| BitMaps |
A bitmap is an array of dots or "pixels" where each pixel (picture element) has a value that represents the color of the pixel. The width of a bitmap is defined by the number of pixels across a row. The height of the bitmap is defined by the number of rows of pixels. Any graphic that is made up of rows of dots is called a "Raster" graphic therefore a bitmap is a raster graphic. The overall printed dimensions of a bitmap is dependent on the dot resolution of the device used to print it. For example if you create a bitmap graphic that is 300 pixels wide and has 300 rows of pixels and then you print this bitmap on a printer that has a dot resolution of 300 dots per inch, you will end up with a printed image one inch square. If you display the same bitmap on a computer screen that has a dot resolution of 100 dots per inch, you end up with an image that is three inches square. This means that bitmaps are "device dependent" where the resolution of the rendering device (i.e. printer or screen) must be taken into consideration when you create the image. If you need to preserve the size of an image from one device to another, (i.e. screen to printer) you must "stretch" or "shrink" a bitmap to fit the desired size. The process of stretching and shrinking involves either adding or removing pixels to or from the original image. As you can imagine resizing a bitmap to a desired size when moving from one output device to another generally causes a severe degradation of the original image quality. Therefore, when creating precise graphics (like bar codes) it is extremely important that the image is created with the same dot resolution of the printer. If you do not know the dot resolution of the printer that will be used to print the bar code then you cannot fully guarantee that the image will be readable by all bar code readers. A type of bitmap called a "Device Independent Bitmap" has been developed as an attempt to solve the device dependency problem however you still end up with distorted images when you render a bitmap on a device that does not have the exact same dot resolution that the bitmap was created with. Another problem with bitmaps is that they require large amounts of memory. For example a bitmap that is 300 pixels wide and 300 lines down (only 1 square inch on a 300 DPI laser printer) and has three bytes per pixel of color information (standard RGB colors) will require 270,000 bytes of memory or disk space. For bar codes, this is a huge amount of space for a very simple graphic made up of a relatively small number of rectangles.
| Fonts |
Although fonts are not normally thought of as graphics, they can be used to produce bar codes. A font is a collection of graphic elements that are assigned to each of the characters in the ASCII or ANSI character set. Because most bar code symbologies encode data by mapping specific characters to specific bar and space patterns, it is possible to use fonts to create bar codes. Unfortunately, fonts have many inherent problems when they are used to create bar codes. The most important problem with fonts when they are used to create bar codes is that they are not "intelligent". Almost every bar code symbology has features like start and stop patterns, check digits, guard patterns, quiet zones and bearer bars. When you use a font to create a bar code you cannot simply select the text for the message that you want encoded and select a bar code font. You first have to insert special characters for the start and stop patterns as well as manually calculate and insert a special character for the check digit. In almost all cases you have to use a special program provided with the font to calculate and add check digits and insert start and stop patterns. Another problem with fonts is that they cannot be scaled in a single direction in most application programs. Some specialized desktop publishing programs allow stretching of fonts in a single direction however most database or word processing programs do not. This means that if you increase the size of a font, both the height and the width change. When creating bar codes, it is extremely important that the width of the bars and spaces remain constant. Typically the height of a bar code font is not adequate and it must be scaled up. When you do this by increasing the font size, the width of the bars and spaces as well as the overall width of the bar code increases proportionally which causes the bar code to be rendered out of spec. In general fonts are the poorest choice for creating bar codes. They offer the least control of all possible methods for creating bar codes.
"Bar code fonts have been known to create EAN/UPC symbols with serious quality defects. The problems may be caused by the inherent design of the font, operator input, or a combination of both..." Uniform Code Council, Inc., Guidelines for Providers of EAN/UPC Symbol Design Software, 1997, Page 13.
"For these reasons, extreme caution should be used when producing EAN/UPC symbols with bar code fonts. They should only be used by highly experienced bar code design professionals utilizing appropriate controls"
This is true when using fonts to create any bar code symbology.
| Metafiles |
The absolute best way to create bar codes is to use a vector style graphic. Instead of containing an actual raster style image (like a bitmap), a vector graphic contains a sequence of drawing instructions that describe how to render the image. For example it might contain an instruction that tells the output device to move to a point exactly two inches down and to the right from the upper left corner of the screen or page and draw solid black rectangle that is exactly a quarter of an inch wide and one inch tall. The Windows metafile (WMF) and the Encapsulated Postscript (EPS) graphics formats are "vector" graphic formats. The prominent features of the WMF format is that it is completely device independent, it supports extremely precise dimensions for all graphic elements (down to 1/100th of a millimeter) and the amount of memory required to store a metafile is extremely small. Best of all, every printer that has a Windows printer driver must support printing metafiles therefore there is never an issue with being able to print metafiles on a particular printer. The characteristics of metafiles are ideal for creating bar codes. As an added bonus, most programming languages and commonly used Windows programs provide built in support for handling metafiles. Metafiles are in fact built from the natural "graphics language" used by Windows for creating almost all graphic elements used in every Windows program. Widows also provides built in clipboard support for the metafile format which makes it extremely easy to move them between applications. The only problems that you might encounter with metafiles is that some service bureaus have trouble printing them on a small number of high resolution film mastering devices. Typically the problems that they encounter are because they are using older, outdated printer drivers. Service bureaus generally prefer the EPS graphics however most Windows programs do not have the ability to render EPS images on screen making EPS files difficult to work with. For example PageMaker for Windows will allow you to insert EPS files into a document however when you do so, PageMaker only displays a rectangle where the image would appear in the document. You will not see the image on your screen unless the EPS file has a TIFF preview embedded in the EPS file. (A TIFF is a type of raster graphic similar to a bitmap. Both EPS and WMF files can contain raster images embedded as part of the vector graphic.)
| B-Coder Pro and B-Coder Lite |
TAL's B-Coder bar code graphic generating software can create bar codes in ANY graphic format - including Windows Metafile (.WMF), EPS, TIFF, bitmap, GIF, JPEG, AI, PCT, PCX, etc... However for the reasons given above we recommend that you one of the vector formats, i.e. WMF or EPS if possible.
| Windows Applications |
- Word, Access, PageMaker, WordPerfect, Quark, etc. Generally in Windows the WMF format is best as all printers can print perfect WMF graphics from Windows however only postscript printers can print EPS (Encapsulated Postscript) graphics. Hence WMF is the "default" graphic format in B-Coder.
| MAC |
If you are going to be printing from a MAC we recommend you use the EPS graphic format in B-Coder. This allows all EPS options including selectable TIFF preview for the EPS.
| Internet |
If you are going to be showing the bar codes on web pages then you will want to use the GIF or JPEG options, however the quality of these bar codes will be much lower as GIFs and JPEGs are raster graphics.
The other graphic formats supported by B-Coder (bitmap, TIFF, PCT, PCX, TGA, CTM, WPG, DRW, etc.)are provided for special situations or for specific applications that have limited graphic support. They are all raster graphics so they should only be used if you have no other choice.
Imaging Device Resolution in DPI* | |
Bit-map Images | 100 - 400 dpi (device dependent) |
Vector Images | 100 - 4000+ dpi (device independent) |
Thermal Bar Code Printers | 100 - 400 dpi (with resident bar code formats) |
General Purpose Printers | 300 - 1200 dpi (laser, inkjet, etc..) |
Image setters | 1200 - 4000+ dpi (i.e. Linotronic printers) |
*Taken from Guidelines for Providers of EAN/UPC Symbol Design Software | |
General purpose printers, especially laser printers, are excellent for producing bar code labels on sheets of pre-cut labels (such as "Avery" labels) or on continuous feed labels. Obviously, for anyone needing extremely high quantities of bar codes on a daily basis thermal transfer printers with their high speed would be better, but for many users general purpose printers, especially laser printers, are preferably. Laser printers are also perfect for creating bar codes on documents, such as medical and legal records, coded "mail-merge" letters, etc. Imagesetters, such as Linotronic printers, are used to create high quality, 2540+ dpi, film positives and negatives for commercial printing. With general purpose printers, including laser, desk top, ink jet, ion deposition, dot matrix and imagesetter, the software used is critical to ensuring readable symbols.
"There is a wide variety of software packages for creating symbols using general purpose printers. Unfortunately, many of these packages are capable of producing symbols with totally unacceptable quality."
UCC Guidelines for Producing Quality Symbols, April 1998
The software used should be able to satisfy the following requirements: Dots Per Bar WidthWhen specifying the narrow bar (module) width the user should be able to specify an integer multiple of the printer dot width. This is best explained with an example. For a 600dpi printer the actual dot width is 1/609.6* = 0.00164". The module width should be specified as an integer multiple of printer dots, i.e. 8 dots per module gives a width of 13.12 Mils and a Magnification Factor of 100.95% 7 dots per module gives a width of 11.48 Mils and a Magnification Factor of 88.33%.
(*A 600 dpi printer with an actual 609.6 dpi)
Module (bar) width defined as 8 printer dots or 13.12 Mils or a Magnification Factor of 100.95%
Module (bar) width defined as 13 Mils or a Magnification Factor of 100%. This is not an Integer number of printer dots. Rounding errors could occur when printing.
The easiest way to achieve the correct module width for your printer is to have software that:
i. Allows you to specify the target printer resolution or finds the resolution for you for the printer you have selected.
ii. Then allows you to specify the module width in "printer dots" (it would already know the "dots per inch"). You would select the number of printer dots that most closely matches the Magnification Factor, or module width in Mils, that you desire. If you wanted 100% magnification an "8 printer dot" width for a 600 dpi printer would be the closest.
| Bar Width Reduction |
The software you select also needs to have an option for "Bar Width Reduction." This is important when printing to any printer that has "dot spread". This includes ink jet printers and "wet ink" printers (but not laser printers). For these printers one dot of bar width reduction is recommended per bar width. For instance for a 300 dpi ink jet printer with a module width of 13.12 Mils (4 printer dots per module width) Bar Width Reduction of one dot would be 3.28 Mils or 25%. Bar Width Reduction is also required when bar codes are going to be printed on a commercial (wet ink) press. In this case the artwork containing the bar code is usually output on film from an Image setter. Image setters have resolutions of 2400+ dpi so the required bar width reduction can be specified exactly. The actual amount of reduction required is determined by the paper and ink used and this should be specified by the printer. If printing to a smooth hard surface, such as a glass bottle, Bar Width Gain may be required. Again, you should consult your commercial printer for his recommendations before generating the bar codes.
| Bar Code Graphic Type |
There are 3 main types of bar code software products:
- Bar Code Fonts
- Bit-map (Raster) Bar Code Generators
- Vector Bar Code Generators
Each is discussed below:
1 Bar Code Fonts
"Bar code fonts have been known to create EAN/UPC symbols with serious design defects. The problems may be caused by the design of the font, an operator input, or a combination of both." UCC Guidelines for Providers of EAN/UPC Symbol Design Software, July 1997.
"Extreme caution should be used when producing EAN/UPC symbols with bar code fonts."
The Uniform Code Council does not recommend the use of fonts. As problems it cites in particular the ability to manipulate the size of individual characters (distortion), spacing between the characters (kerning) and the possibility of font or resolution substitution at the output stage. However there are many other problems with bar code fonts. The user cannot specify the module (bar) width exactly in printer dots. Fonts do not support Bar Width Reduction. Nor do they support many of the features specific to bar code symbols such as Bearer Bars, Quiet Zones, independent symbol height and module (bar) width specification, symbol rotation and support for binary data (including ACSII nulls in Code 128, Code 39, Code 93 and PDF 417). In addition, most fonts do not automatically calculate and add check digits and other security features to bar codes.
2 Bit-map Bar Code Generators
A bit map image is device dependent. This means a bitmap of a one inch square to be printed at 300 dpi would be 300 pixels across by 300 pixels down. If a bar code designed to print one inch square on a 300 dpi printer were printed instead on a 600 dpi printer the resulting bar code would be � inch x � inch. This is because there would only be 300x300 pixels in the image instead of 600x600. The other problem with bit-maps images is their size. If you are printing to a 200 dpi printer a one inch square would contain 200 x 200 =40,000 bits of data. This is bad enough but to a higher resolution printer, such as a common 600 dpi printer it would be 360,000 bits of data (and 6.5 million bits of data for a 2540 dpi Image setter!!). These huge files not only use large amounts of computer memory they also print extremely slowly.
3 Vector Bar Code Generators
Vector graphics are perfect for defining bar code images. A vector image is a set of drawing commands that precisely defines the edges of each bar and specifies how to fill in the area created within the defined edges. Vector images are completely device independent as they are a set of precise commands instead of a collection of dots. A 1" x 1" box will print 1" by 1" on a 100, 600 or 2540 dpi printer! When a vector image is sent to a general printer the printer’s software converts it to a raster image so that it can print it. The Raster Image Processor in the Printer converts the precise path commands in the vector graphic into a series of pixels. Hence the exact measurements of the image are influenced by the resolution of the printer. A higher resolution printer will be able to more precisely match the exact measurements of the vector graphic. A lower resolution printer will need to round the dimensions to the nearest integer number of printer dots. This is why it is so important, especially in printers of 600 dpi or less, to specify the module (bar) width in integers of printer dots (see part 1 above). Vector bar code graphics are also much smaller than other bar code graphics so they print many, many times faster. For instance, a typical 1" high UPC code at 100% magnification would create a 149 KB bitmap for a 600 dpi printer. A Windows Metafile (WMF) vector graphic of this bar code would be 2 KB and an Encapsulated Postscript (EPS) vector graphic with a TIFF preview would be 48 KB and 29 KB without the TIFF preview. Windows Metafiles (WMF) are the best graphic format for bar codes in Windows and EPS in the Mac (Macs do not support WMF graphics). Once the bar code is created by any bar code software it should not be resized, scaled or stretched. If the bar code is to be transferred to a second party, information, such as the minimum printer resolution for that bar width, should be communicated.
| Bar Code Verification |
As with Thermal Transfer printers, it is important to test the output from General Purpose printers using a bar code verifier. The UCC recommends using the test symbols: 0 12345 01234 1 6 78912 56789 0 If they fall below a grade B check that you have specified a Magnification Factor (or module width) that corresponds to an integer number of printer dots per module (bar) width. Bar Width Reduction may also be required as discussed above. If the user does not have a bar code verifier he can submit the bar codes to a qualified testing organization. If nothing else, at least they should be tested with a bar code reader.
| Further Information |
For the complete, in-depth, guidelines please refer to the following Uniform Code Council documents
- UCC Guidelines for Producing Quality Symbols, April 1998
- Guidelines for providers of EAN/UPC Symbol Design Software, July 1997
- UCC Technical Bulletin #1, April 1997
You can download a FREE demo for TAL’s bar code generating software, B-Coder Pro and the ActiveX control. Use this to create bar codes in any size and any graphic format. Take the recommendations above to create bar codes as WMF Vector graphics and define the module (bar) width in "Printer Dots". B-Coder Pro automates bar code production on labels and documents from MS Word, Access, PageMaker and other Windows application programs. A FREE demo also available for the TALtech Bar Code DLLs. These programmers’ tools allow developers to add high resolution, completely device-independent, bar code printing capability to their custom applications, royalty free! As with B-Coder Pro, the DLLs fully comply with industry recommendations to print 100% compliant bar codes.
|W|P|114782613376294324|W|P|Printing Perfect Bar Codes From ANY Printer|W|P|venkat@sgdnetworks.com| Recently the Uniform Code Council (the organization that governs UPC bar codes) announced that starting in January 2005, they will require that all retailers and trading partners in the United States and Canada that presently scan 12-digit UPC bar code symbols be capable of scanning 8 digit EAN-8 and 13 digit EAN-13 bar code symbols as well. Furthermore, the UCC strongly recommends enhancing systems to accept bar code data of up to 14 digits in preparation for a new numbering system called GTIN (Global Trade Identification Numbers) that will eventually be used to identify products world wide. There is a great deal of confusion about what this all means among companies that both print bar codes on their products as well as with companies that scan bar codes into retail point of sale or inventory systems. Many people mistakenly believe that UPC bar code numbers are going to be phased out altogether or replaced with a new type of bar code called a GTIN bar code. A GTIN bar code is not a new type of bar code at all. GTIN numbers are simply 14 digit numbers that will be used to identify products. GTIN numbers are fully compatible with standard UPC-A, EAN-8 and EAN-13 bar code numbers therefore UPC and EAN bar codes will continue to be used well into the future. All that is really going on is that the Uniform Code Council is recommending that anyone that currently has a system in place for reading 12 digit UPC bar codes should modify their bar code databases so that they can accept up to 14 digit numbers in bar codes used for identifying products. This will allow existing bar code scanning systems to be used to read any of the 4 primary types of bar code numbers used for product identification (UPC-A, EAN-8, EAN-13 and the newer GTIN numbers). UPC bar codes will continue to be encoded using the UPC-A bar code symbology, EAN-8 numbers will continue to be encoded with the EAN-8 bar code symbology and EAN-13 numbers will continue to be encoded with the EAN-13 bar code symbology. The newer GTIN numbers will be encoded using either the Interleaved 2 of 5, the EAN/UCC-128, or RSS14 bar code symbologies. The Interleaved 2 of 5 and EAN/UCC-128 bar code symbologies have been in existence for many years and almost all bar code scanners already have the ability to scan these types of bar code symbols therefore no changes will need to be made to existing bar code scanner hardware. All that has to change is the way that the numbers are stored in a database. The RSS14 bar code symbology is a relatively new symbology therefore only a small percentage of the existing installed base of bar code scanners are capable of reading RSS14 bar codes. For example, suppose that you have a retail point of sale or inventory system that stores all bar code data in a database and the data field that stores the bar code data is restricted to hold only a 12 digit number (standard UPC-A numbers). To support the new standard, you would need to modify the database so that the bar code data field will be able to accept either an 8 digit, 12 digit, 13 digit or 14 digit number. If your database already contains existing data that is shorter than 14 digits in length, they are recommending that you pad the existing data with leading zeros so that all numbers will end up being 14 digits in length. All TAL Bar Code software products including our Bar Code ActiveX control, our bar code DLLs and B-Coder Professional have always supported UPC-A, UPC-E, EAN-8, EAN-13, Interleaved 2 of 5, EAN/UCC-128 and RSS14 bar codes therefore you will be able to continue using the version of B-Coder Pro, our bar code ActiveX control or our bar code DLLs that you have for a very long time - even with the changes that are supposed to occur in 2005. For more information on the 2005 changes to the bar code world, please visit GTIN Implementation Guide Preparing for the 2005 Sunrise Date | |
When you purchase a bar code scanner, the most important decision that you will need to make is how to interface the bar code scanner to your computer. Modern bar code scanners are normally available with one of three "output options" - either "Keyboard Wedge" output, RS232 serial output, or USB output. The following is a description of each of the three output options and how they work and the differences between them. Which option you choose will depend mostly on the software that you will be scanning the bar codes into an how you want everything to work as well as the types of ports available on your PC. Keyboard Wedge Output The "Keyboard Wedge" output option is the most common option. To interface a keyboard wedge bar code scanner to a PC, you would disconnect the keyboard from the keyboard port on the PC, plug the bar code scanner directly into the keyboard port and then connect your keyboard to a small "jumper cable" on the end of the bar code scanner cable (so that you do not lose the functionality of your keyboard). In other words, you are connecting the bar code scanner in the line between your keyboard and you PC. (One benefit of this is that the bar code scanner gets its power from the keyboard port so you do not need to connect any type of power supply to the scanner.) When you scan a bar code with a keyboard wedge scanner, the data that is encoded in the bar code goes into the PC through the keyboard port so that it appears to whatever software is running in the PC as if it were being typed in on the keyboard. (i.e. The bar code scanner behaves exactly like a second keyboard connected to the PC.) With a keyboard wedge scanner, you do not need any additional software. You simply plug the scanner in and start scanning bar codes. The keyboard wedge interface is extremely simple and in most situations, you do not need to make any changes to the software that you will be scanning the bar code data into. The main advantage of the keyboard wedge interface is that it works just like a keyboard. You put the cursor where you want the bar code data to go and then scan the bar code and the data pops in just as if you typed it on the keyboard. The disadvantage of the keyboard wedge interface is that it works just like a keyboard. If the cursor is not in the correct input field in the correct application program, then, when you scan a bar code, the data still gets entered into the PC as if it is being typed in on the keyboard. If the cursor is not in the right place or if the application that you want the bar code data to go into does not have the input focus, the data goes to the wrong place or possibly the wrong application program. Also, if you need to modify the data in any way before it goes into the application program running in the PC, you cannot do this. For example, suppose that you need to parse the bar code data so that separate parts of the data goes to different input fields or if you want to add a date or time stamp to the bar code data, it is not possible with a keyboard wedge scanner.
RS232 (serial) Output The RS232 output option means that you would connect the bar code scanner directly to an available RS232 serial port on the back of your PC. (RS232 output scanners also normally require an AC adapter to supply power to the scanner because the RS232 port cannot supply enough power to run a bar code scanner.) With a RS232 output scanner, you would also need to either develop your application software to open and read in data from the RS232 serial port directly or use a software interface like the TALtech WinWedge software products. (http://www.taltech.com/products/winwedge.html) The main advantage of the RS232 output option is that you can develop your application so that it does not matter where the cursor is. When you scan a bar code, the data always goes to the correct place in your application program because the data from the scanner is going directly into the application program and is not going through the keyboard port. The RS232 interface requires a little more work up front because you either need to develop your software to work directly with the RS232 port (or configure the WinWedge software to act as the interface between the RS232 port and your application software) however the advantage to this approach is that you end up with a much more robust application that does not rely on the user making sure that the cursor is in the correct place in your application program before scanning a bar code. If you need to create a bar code application that is completely "idiot proof", then the RS232 interface option is by far the best choice. The RS232 output option also makes it possible to manipulate the data that you receive from the bar code scanner before writing the data to the application program where you want the data to go. For example, if you want to parse the bar code data or add a date or time stamp to it, the RS232 serial output option would allow you to do this. One issue that you may run into is that some newer desktop PCs and almost all new laptop computers do not come with any RS232 serial ports. The problem is easily solved by purchasing an "Add-on" RS232 serial adapter for the PC. There are even add-on RS232 serial adapters available the connect to a USB port on a PC. A single port add-on serial adapter that connects to a USB port should cost no more than $30 and you can find them at any computer or office supply store.
USB Output Bar code scanners that have a USB output can work one of two ways. The first is that they can work exactly like a Keyboard Wedge scanner and the second is that they can work exactly like a RS232 serial output scanner. When you purchase a bar code scanner that has a USB output, you normally will also need to specify which interface you want - either "USB Keyboard Wedge" or "USB RS232 serial port". (Some bar code scanners are only available with the USB Keyboard Wedge option). USB Keyboard Wedge Scanners A USB Keyboard Wedge bar code scanner works exactly like a "Keyboard Wedge" bar code scanner except that instead of connecting the bar code scanner to the keyboard port on the PC, you plug it into a USB port. When you do this, the bar code scanner is recognized by the PC as a second keyboard device and when you scan a bar code, all bar code data goes into the PC just as if it were being typed in on a keyboard. Just like a standard keyboard wedge scanner, no additional software is needed. Windows will automatically recognize the scanner and treat it as if it were a second keyboard connected to your PC. Since the USB Keyboard Wedge option works exactly the same as a standard Keyboard Wedge bar code scanner, there is really little difference between the two other than the port that you plug the scanner into. USB scanners all get their power from the USB port so you do not need an additional power supply. The only real advantage to a USB Keyboard Wedge scanner over a Standard Keyboard Wedge scanner is when you need to connect the scanner to a laptop computer that does not have a keyboard port. USB RS232 Serial Scanners A scanner that has a USB RS232 serial interface will come with a special "Driver" program that you will need to install in the PC that you connect the scanner to. The purpose of the driver is to create a "Virtual RS232 serial port" that works exactly like a physical RS232 port. After you install the driver that comes with the scanner and connect the scanner to a USB port on your PC, Windows will think that it has a new RS232 serial port and any serial communications software (including WinWedge) will be able to open this "Virtual RS232 serial port" just as if it were a standard RS232 serial port built into the motherboard of the PC. In other words, the scanner works exactly like a RS232 serial output scanner except that it connects to the PC through the USB port. Everything that was said above in the paragraph about RS232 serial output scanners applies to a USB RS232 serial scanner. The only difference between the two is that the USB RS232 serial scanner plugs into a USB port on the PC instead of into a RS232 serial port. This means that your PC does not need to have any RS232 serial ports installed in it and it also means that the bar code scanner will get its power from the USB port therefore you do not need any additional power supply. A USB RS232 serial bar code scanner is basically equivalent to a standard RS232 serial scanner that comes with a built in USB RS232 add-on adapter with the advantage that you do not need an external power supply.
|W|P|114782573810078040|W|P|Which Bar Code Scanner Interface is right for me? RS232, Keyboard, or USB.|W|P|venkat@sgdnetworks.com
Bar codes provide a simple and inexpensive method of encoding text information that is easily read by inexpensive electronic readers. Bar coding also allows data to be collected rapidly and with extreme accuracy. A bar code consists of a series of parallel, adjacent bars and spaces. Predefined bar and space patterns or "symbologies" are used to encode small strings of character data into a printed symbol. Bar codes can be thought of as a printed type of the Morse code with narrow bars (and spaces) representing dots, and wide bars representing dashes. A bar code reader decodes a bar code by scanning a light source across the bar code and measuring the intensity of light reflected back by the white spaces. The pattern of reflected light is detected with a photodiode which produces an electronic signal that exactly matches the printed bar code pattern. This signal is then decoded back to the original data by inexpensive electronic circuits. Due to the design of most bar code symbologies, it does not make any difference if you scan a bar code from right to left or from left to right.
The basic structure of a bar code consists of a leading and trailing quiet zone, a start pattern, one or more data characters, optionally one or two check characters and a stop pattern.
There are a variety of different types of bar code encoding schemes or "symbologies", each of which were originally developed to fulfill a specific need in a specific industry. Several of these symbologies have matured into de-facto standards that are used universally today throughout most industries. The symbologies supported by B-Coder, The TAL Bar Code ActiveX control and the TAL Bar Code DLLs are those most commonly used across all industries. The different symbologies have different capabilities for encoding data. For example the UPC symbology used to identify retail products always contains 12 numeric digits whereas the general purpose Code 39 or Code 128 bar code symbologies can encode variable length alphanumeric data up to about 30 characters in length. These types of bar codes are called "linear symbologies" because they are made up of a series of lines of different widths. Most commercially available bar code scanners are able to read all of the different linear bar code symbologies therefore you do not need different readers for different types of bar codes. New "2-Dimensional" bar code symbologies like PDF417, Aztec Code and Data Matrix are also now available that can encode several thousand bytes of data in a single bar code symbol including text or binary data. The newer 2D bar code symbologies typically require special bar code readers that are designed specifically for reading them.
The primary purpose of a bar code is to identify something by labeling the item with a bar code containing a unique number or character string. Bar codes are typically used with a database application where the data encoded in the bar codes is used as an index to a record in the database that contains more detailed information about the item that is being scanned. For example, when a checkout clerk scans a bar code on a product in a grocery store, the bar code data is fed to a computer that looks up the information in a central database and returns more detailed information about the item that was scanned including possibly a description of the item and a price. By using bar codes, the grocery store does not need to put a price tag on each item in the store and they can also change the price for a particular item by modifying a single entry in the central database. They can also track how much of a product is currently in stock so that they know when to re-order more of each item as the number of items in stock falls.
Bar codes also provide a quick and error free means for inputting the data into an application running on a computer. By using bar codes, the potential for errors from manual data input is eliminated. Another typical application for bar codes is therefore for inputting data without having to type. For example you could encode name or address data in a bar code on an ID badge and then scan the ID badges to input a persons name into a computer program instead of typing the information.
| How much data can you actually encode? |
The different bar code symbologies support different types and amounts of data therefore you normally choose a particular symbology based on the type and amount of data that you want to encode in your bar codes.
| Symbology | Data Capacity |
| UPC-A | 12 numeric digits - 11 user specified and 1 check digit. |
| UPC-E | 7 numeric digits - 6 user specified and 1 check digit. |
| EAN-8 | 8 numeric digits - 7 user specified and 1 check digit. |
| EAN-13 | 13 numeric digits - 12 user specified and 1 check digit. |
| Code 39 Code 93 Code 128 EAN-UCC 128 | Variable length alphanumeric data - the practical upper limit is dependent on the scanner and is typically between 20 and 40 characters. Code 128 is more efficient at encoding data than Code 39 or Code 93. Code 128 is the best choice for most general bar code applications. Code 39 and Code 128 are both very widely used while Code 93 is rarely used. |
| I 2 of 5 | variable length numeric data - the practical upper limit is dependent on the scanner and is typically between 20 and 50 characters. |
| Data Matrix | Data can consist of any type of data including binary or alphanumeric and be up to 3116 bytes in length. |
| Aztec | Data can consist of any type of data including binary or alphanumeric and be up to 3750 bytes in length. |
| Maxicode | Maxicode can hold up to 93 alphanumeric characters or 138 numeric digits. Maxicode is used almost exclusively for United Parcel Service package identification. |
| PDF417 | PDF417 is a little more complex and it is difficult to say exactly what its capacity is because it depends greatly on the type of data that you encode in a PDF417 symbol as well as the amount of error correction capacity that you choose to use in a PDF417 symbol. For general binary data with no error correction enabled, a single PDF417 symbol can hold up to 1108 bytes. If the data consists of all numeric digits, then a single PDF417 symbol can hold up to 2725 digits. If the data consists of alphanumeric data, you can encode a maximum of 1850 bytes. If you have a mix of alphanumeric and binary data, the capacity will be somewhere between 1108 and 1850 bytes and will depend on the content of the data. All of our bar code software products use an extremely efficient encoding algorithm that will squeeze the maximum number of bytes possible into a PDF417 symbol however it still must work within the limits of the symbology specification. |
Whereas 2D bar codes offer more security and safety for their subjects, 1D bar codes, as read by 1D bar code readers, are more practical for wide scale operations. The reason? Bar codes with single layers are more affordable to produce than the double layered inscriptions of 2D bar codes. Hence, there is a large demand for 1D bad codes and 1D bar code readers in today’s busy times.
A 1D bar code reader is an essential, and preferred, tool for retail establishments where items pass through a counter several times a minute. A 1D bar code reader is also the device of choice for establishments that seek to monitor the ingress and regress of people, when such establishments are not considered as high security areas.
Why Are There 1D And 2D Bar Code Readers?
Though a universal type of bar code would greatly help a variety of industries, the various types of bar codes today, which are not limited to 1D and 2D bar codes alone, have provided a wider selection for different enterprises with distinct needs.
The creation of 1D and 2D varieties of barcodes stemmed from the attempts of bar code manufacturers to improve on the existing formula. But each improvement served a specific purpose distinct to its kind, hence, such was retained. Today, there are a lot of 2D bar code readers for 2D bar codes and 1D bar code readers for 1D bar codes. This is a sign of a very healthy industry!
Kinds Of 1D Bar Code Readers
A 1D bar code reader can come in many forms. Portable 1D bar code readers are the most commonly used in many establishments. Since a 1D bar code reader is generally manufactured for a market that experiences brisk operations, it is easy to assume that the sheer transportability of these portable 1D bar code readers make them more appealing to their target audience.
A 1D bar code reader can also come in the form of scanner-type 1D bar code readers. These are seldom used, however, as their more mobile counterparts are more appropriate for the market that 1D bar code readers seek to cater to.
The Road Ahead For 1D Bar Code Readers
It is understandable that people would feel hesitant about investing on a 1D bar code reader, mainly because of fear that the 1D bar code design would soon become obsolete. These fears are quite unfounded.
There will always be a need for a 1D barcode reader because there will always be a market for 1D bar codes. As we have mentioned earlier, a good number of establishments actually prefer 1D bar codes and 1D bar code readers because they are more resilient and responsive to businesses with busier processes. This accommodative nature of 1D bar code readers should assure everyone that they are here to stay and investing on them would be a prudent choice.
This, of course, is aside from the fact that 1D bar code readers are cheaper than other types of this device.
|W|P|114776467693903352|W|P|Investing On A 1D Bar Code Reader|W|P|venkat@sgdnetworks.comThey’re not really the greatest invention of the recent century. To claim such would be an unbelievable hyperbole. But barcode readers have attained, and kept, their place as indispensable tools for many businesses the world over. Though the world in general may not have been revolutionized by their introduction to several industries, barcode readers have made quite a fortune for benefiting enterprises and barcode reader manufacturers alike.
Indeed, barcode reader manufacturers have enjoyed tremendous and sustained profit by reason of their main products. Barcode readers have become a must in certain fields that demand for the said products has never waned, instead, has experience a steady increase throughout the years. As a result, barcode reader manufacturers are always aiming to discover new applications and improvements for their cash cow.
The Driving Force Behind Barcode Reader Manufacturers
Like most industry giants, barcode reader manufacturers discovered a need, and they provided for such a need through their worthy invention: barcode readers.
Before barcode reader manufacturers started to distribute their products, businesses involved with the identification and verification of items, especially those in minor or major transits, have been fraught with errors and delays. The reason? Everything was being carried out manually, hence the processes are susceptible to human fallibilities.
Barcode reader manufacturers offered barcode readers to solve these problems. The bread and butter of these barcode reader manufacturers was able to make things more accurate and convenient, resulting in a more efficient and speedy execution of the said processes.
Barcode Reader Manufacturers And The Developments In The Industry
Since the time they have started to offer barcode readers for the usage of relevant businesses, barcode reader manufacturers have likewise introduced improvements over the original models. Today, barcode readers come in a variety of forms, care of the many barcode reader manufacturers in the industry.
Fixed readers, portable batches and portable RF readers are just some of major types of barcode readers that barcode reader manufacturers are currently selling in the market. They come in further variations, of course. Barcode reader manufacturers have also developed scanner-based barcode readers, camera-based barcode readers, and CDD barcode readers for businesses with equally varied needs.
Barcode reader manufacturers also change the products to conform to current demands. For example, barcode reader manufacturers today offer barcode readers that could decode numeric barcodes. These barcode reader manufacturers also offer barcode readers that could translate barcodes using alphabetic characters. They also offer barcode readers that could identify and verify barcodes with lines of fixed or varying lengths.
Barcode Reader Manufacturers And The Future
Judging from history, only good things can be expected from barcode reader manufacturers in the coming years. The leading barcode reader manufacturers of today such as Symbol Technologies, Intermec, Opticon, Argox and American Microsystems, Ltd. Are already positioning themselves for their continued success in the future. They are heavily investing on their research and development departments to come up with better applications and features for the barcode readers they will manufacture for tomorrow.
It is an exciting time for both interested businesses and barcode reader manufacturers. Fueled by unceasing success, the future does look bright for those tools that have helped boost the efficiency of countless businesses throughout the years.
|W|P|114776460289779676|W|P|The Future For Barcode Reader Manufacturers|W|P|venkat@sgdnetworks.comThere are many fancy add-ons for computers, but the basic components of the computer are simple and universal. If 1 of these main components is missing, it’s not a computer.
The 4 essentials of every computer system are: a motherboard, a Central Processing Unit (CPU), memory, and a hard drive. These components are installed in a case to which are attached a monitor, a keyboard and a mouse. That’s your basic computer.
Mother WHAT?
The motherboard ("mobo" for short) is the foundation. Everything attaches to the mobo -- the CPU, memory, hard drive, monitor, mouse, keyboard, add-on cards, even additional peripherals like printers, scanners, and speakers. The motherboard is like the nervous system and skeleton of the human body -- it provides support for the internal components and also passes information between the computer parts.
CPU
If the motherboard is the nervous system, then the CPU is the brain. Most of the mathematical manipulations that make computers operate are done by the CPU. Other components may also have their own processors, but their results still have to be passed through the CPU.
The speed of the computer is usually measured by the speed of the CPU. Even though other factors also affect overall speed, the CPU rating is generally seen as the single most important measure of performance.
Modern CPUs are usually rated between 2.0 GHz and 3.0 GHz, although each passing month will see increasing performance. This measurement refer to the number of calculations the processor can make in 1 second. The higher the number, the faster (better) the computer.
CPUs generate a lot of heat doing this work, so they need a heat sink and fan to keep them from overheating. Heat is a major enemy of the computer and directly affects its life span.
Computer Memory
RAM (Random Access Memory) is the part of the computer that stores information the computer needs while it is operating. It is Random Access because the computer can get the data in any order, not necessarily the order in which it is stored. Generally speaking, the more RAM the better. 512 to 1024 megabytes is common for memory.
The most common type of RAM these days is DDR-SDRAM, which stands for double-data-rate synchronous dynamic random access memory. We already know what the RAM part means. DDR means that the data is accessed twice as fast as ordinary RAM.
The latest type of RAM is DDR2. It offers even faster access rates and is quickly becoming the standard for computer memory.
Hard Drive
All the data contained in RAM is lost when the computer is turned off, so there has to be a place to store it permanently. This is what the hard disk is for.
It holds the computer’s operating system. An operating system like Windows uses around 4 gigabytes of hard drive space. The extra space is used to install computer programs and to store your personal data.
80 gigabyte hard drives are common, but 400 GB units are available. Furthermore, you can install more than 1 in a computer case for added security and convenience.
Peripherals
All you need to complete the basic computer system is a monitor, keyboard and mouse.
Accessories like a printer or scanner are useful for office work, and gamers will probably want to add speakers and joystick controls.
So there you have it. The basic computer needs just 7 major components. For the best performance, these components must integrate well. The motherboard is the most important component for determining the type and specification of the other parts. Choosing an appropriate mobo for your computer needs is the first step and may require a quick call to your local geek.
Soon YOU will be considered the local geek!
|W|P|114776450725333139|W|P|Computer Components for Idiots|W|P|venkat@sgdnetworks.comPersonal asset preventive maintenance software exists to help people manage and maximize the value of their assets. Common types of personal asset preventive maintenance software deal with taxes and investments. Software that manages other types of personal assets, such as property, is also available.
Personal tax software can help users avoid overpaying taxes while also streamlining the tax-paying process. Some advantages include information about available tax deductions and the option to electronically file the required forms. To help maximize the user’s deductions, the programs require comprehensive information about the user’s assets. This information is then processed and the user is alerted to all available deductions. Some software has advice for investors on how to best take advantage of tax laws. While filing electronically usually costs around $15, some tax software includes the option to file electronically for free. Filing electronically allows the taxpayer to receive his or her refund more quickly.
Several money management software programs like Quicken and Microsoft Money can be used as personal asset preventive maintenance software. These programs have features like automatic bill pay, budgeting features, and savings and investment advice and information. Automatic bill pay saves the user from having to remember when a bill is due. This prevents the user from having to pay late fees if the bill is not paid on time. Most personal asset preventive maintenance software programs include budgeting features that allow users to plan for the future and forecast how much money they will have available. The investment information and advice helps the user to maintain savings and retirement funds by keeping investors aware of current market trends and future predictions.
Personal asset preventive maintenance software helps people avoid financial emergencies by providing money management assistance. Such software makes personal finance less stressful and time-consuming.
|W|P|114776318989625933|W|P|There is a great need for preventive maintenance in correctional institutions. The public would be at risk if penal facilities waited to solve problem|W|P|venkat@sgdnetworks.comThere is a great need for preventive maintenance in correctional institutions. The public would be at risk if penal facilities waited to solve problems until after they manifested themselves. Correctional institution preventive maintenance software is necessary to ensure that life in the facility runs smoothly and none of the prisoners escape. As the governments and other organizations allot revenues for correctional facilities, there may be debate about the costs of such maintenance. Although the software is expensive, it is both effective and necessary.
The best way to implement preventive maintenance software in correctional institutions is to integrate it in facilities statewide. This provides a uniform plan for all of the penal institutions and makes it easier for such facilities to work together if need be. This also assures that all of the institutions will be equally maintained and none will be in worse condition than the others. As with many other large institutions, standardization of correctional facilities is of paramount importance.
There are many goals of correctional institution preventive maintenance software, including maintaining of the prison, reducing or eliminating emergency repairs, and systematically updating the information database. The need to maintain the physical facility is obvious – the safety of the public and the living conditions of the inmates depend on the prison being well-maintained. The need to avoid emergency repairs is parallel to the maintenance of the facility. The integrity of the facility would be disturbed if the building suddenly needed to be repaired, creating a breach in the orderly pattern of operations. Finally, the creation of a comprehensive database makes it easier to keep accurate records and to share information between facilities.
Correctional institution preventative maintenance software streamlines the operations of the facilities and minimizes unpredictable events. In the long run, it saves the taxpayers’ money by making the institutions more efficient.
|W|P|114776311778591691|W|P|Correctional Institution Preventive Maintenance Software|W|P|venkat@sgdnetworks.comComputers often break down at the worst of all times. These problems can be averted, or at least minimized with preventive maintenance. Several methods of keeping computer hardware in good working order deal with the external components of the computer, such as the keyboard and monitor. For example, it is important to keep the processor away from excess heat and moisture. There are also computer hardware preventive maintenance software programs that can help with the upkeep of other internal aspects of a computer.
While it is rare to find a CMMS that works on all of a computer’s hardware, many different programs can be utilized simultaneously. Some computers have periodic automatic updates available that can be downloaded and used to improve the computer’s performance. Other software programs, known as disk defragmenters, manage hard drive space so that software programs take less time to access. Programs known as hardware diagnostic utilities can check the computer’s hardware components and alert the user about any potential failures. Since some new hardware will not always work on all computers and could cause existing hardware to malfunction, it is important to have a CMMS program to ensure that the new hardware is compatible with existing hardware.
Antivirus programs are another important component of computer hardware preventive maintenance software. Computer viruses have become increasingly common in recent years and can render a good computer useless. While computer viruses mainly attack software programs, they can ruin hardware as well. Several manufacturers make reliable antivirus software. A couple of well-known companies are Norton and McAfee. As with much preventive maintenance software, these programs are usually available for a free trial period before the user must pay a subscription fee.
Computer hardware preventive maintenance software is necessary to keep computers in good working order. This software manages aspects of computer hardware that would be difficult and time-consuming for even the most computer savvy users.
|W|P|114769447639307899|W|P|Computer Hardware Preventive Maintenance Software|W|P|venkat@sgdnetworks.comThe other piece of vital equipment to accompany the rack mount computers and the monitors are the rack mount computer keyboards. Rackmount computer keyboards are built with durability and reliability in mind.
Most keyboards in home systems get attacked by cookie crumbs, soft drinks, children’s sticky fingers and a whole host of other awful things and yet, for the most part, they keep on functioning. But they’ll break down soon enough in the desert or on a glacier because they’re not made to withstand those harsh environments. The keyboards must be made of materials that will not rust or corrode, will not malfunction in extreme heat or cold and will continue to operate no matter what the workload.
Rack mount computer keyboards are manufactured with two things in mind -- easy compatibility with the rack mount system and durability of the keyboard itself. Essentially, manufacturers chose the finest keyboard on the market and adapted it to conform easily to the requirements of rack mount computer systems. Made to slide into the rack mounts they fit easily into any 19-inch standard rack. The keyboard of choice became the Qtronix, which has become the gold standard of rack mount computer keyboards. Manufactured to the highest standards available, the Qtronix is made to operate without failure under extreme circumstances.
Because of high user demand for rack mount computer systems, monitors and keyboards, the industry prides itself on quality manufacturing. There is no higher standard to achieve than to be recognized by the US military as a supplier of top quality products that soldiers in combat situations can depend on, explorers in the Artic can rely on and that any other user of these products can absolutely depend on.
|W|P|114769444131736136|W|P|Rackmount Computer Keyboards|W|P|venkat@sgdnetworks.comSamsung laser toner is just as popular as its Hewlett-Packard and Brother counterparts. Samsung is a group of products and services that began in Korea in 1938. Today Samsung operate five different business areas: Telecommunications, Digital and Home Appliances, Digital Media, LCD, and Semiconductors. They started their Electronics section in 1969. Today they are one of the top 100 brands in the world, and their printers and cartridges continue to gain a loyal following.
You can buy Samsung laser toner from their official website. There you will find a complete list of all their products. Enter “laser toner cartridge” in the website’s search field and start comparing prices. You are guaranteed to get a quality from this site. Their website offers full specifications, so that you can find the right cartridge for your printer.
Another option is to go to the PCWorld website. Look for “printers” in the drop-down menu. They have a database of websites selling quality third-party laser toner. You can search for “Samsung” via a menu bar on the left. One color ink cartridge is available for under $30, for example. Be careful when you buy third-party laser toner products. Some of these will be sold as “compatible” or “remanufactured” but aren’t up to specifications with the manufacturer’s original standards. One good review website is Epinions, which allows users to rate all kinds of products, including laser printers and accessories, so that you can get a non-marketing perspective on products you are looking to buy.
You can find a list of authorized retailers of Samsung products on their website. That way, you won’t accidentally end up buying a counterfeit Samsung laser toner cartridge.
|W|P|114769440303575150|W|P|A Review of Samsung Laser Toners|W|P|venkat@sgdnetworks.comBrother is right up there with HP and Samsung as one of the most sought-after brands of laser toner. The Japan-based Brother Industries was first famous for its sewing machines. It went on to produce all kinds of office equipment, such as machine tools, fax machines, label makers, printers, and other office equipment. They began making dot-matrix printers in the 1970s. In the 1980s, after HP blew up the market, Brother began releasing their own laser printers to consumers, and to other companies under the name of OEMed. Brother has a great reputation for printers and printing accessories.
You can buy new toner from Brother. There you will find plenty of personal, home, and small business laser toner cartridges and refills. You can also buy new toner refills in bulk, for middleweight to heavyweight business in need of massive amounts of toner on a daily basis.
One popular Brother laser toner cartridge costs about $34 from their website. This will yield about 2200 pages at 5% printing capacity. This percentage means that 5% of the page is assumed to be covered in ink. If you print a lot of photographs, that number will be much lower.
Be careful when buying Brother toner from third-party distributors. They will offer you lower prices under the umbrella terms of “compatible” or “remanufactured” laser toner cartridges. While some of these are perfectly reputable and suitable for a full range of printer uses, many others are below par. These phony cartridges will produce bad printing results and possibly damage your printer. Sometimes a third-party distributor might even package phony cartridges in real Brother packaging. You can find a list of authorized Brother retailers at their website.
|W|P|114769436673576400|W|P|A Review of Brother Laser Toners|W|P|venkat@sgdnetworks.comHewlett-Packard is, along with Brother and Samsung, one of the most readily available brands of laser toner. This is due, in part, to the fact that HP was first to release a laser toner inexpensive enough to catch the attention of the average consumer, in 1984.
Prices on laser printers were much higher back then, sometimes costing $500. But the price on laser toner refill was a lot lower – about $30 a cartridge. Today, you can buy an HP laser printer for less than $200, but the toner replacements can cost as much as $80 if bought new from the manufacturer.
You can also buy remanufactured laser toner cartridges from HP. These are cartridges that were used up by the previous user and sent back to HP to be remade and refilled. These remanufactured cartridges cost about half as much as the new ones. These are almost exactly the same quality of new, and most people can’t even tell. You only really need to buy new cartridges if you are a professional businessperson who needs to create documents of completely reliable quality.
HP laser toner can range from 50 cents for an unrated third-party remanufactured cartridge, to several hundred thousand dollars for a bulk shipment of a few thousand new cartridges direct from the manufacturer. Your needs probably fall somewhere between these two extremes. One popular HP cartridge is the HP No. 56 Black Inkjet print cartridge. This well received toner refill starts at about $14 and can climb as high as $30 via PC World-approved third parties.
A popular color laser toner refill from HP is the HP 97 Tri-Color Inkjet Print cartridge, starting at $23.
|W|P|114769433759184425|W|P|A Review of HP Laser Toners|W|P|venkat@sgdnetworks.comLaser toner refills can be expensive. Over the life of the printer, expect to spend many times more on laser toner refill than you paid for the printer itself.
Laser printers have two chief replaceable components: laser toner cartridges and drums. The laser toner is basically the ink for the paper. The drum is the cylindrical metal roller that applies the ink to the paper. Sometimes printers are designed for cartridges and drums to be separately replaceable; other printers are designed for cartridge-and-drum units bought as one. While the laser toner will last only a few thousand pages in most home printers, drums will last tens of thousands of pages. If you have to replace the drum every time you replace the cartridge, your printing costs will increase significantly. Therefore, if you don’t yet have a printer, get one with separate slots for a laser toner cartridge and drum.
If your laser toner ever gets low, a warning light will appear on the front panel of your printer. When this happens, don’t replace the cartridge just yet. You can put off spending the necessary money by removing the cartridge, shaking it gently back and forth a few times to re-spread the toner, and replacing the cartridge. The warning light might still stay on, but the cartridge will have been manually “renewed” for a few dozen (or few hundred, in some cases) more pages worth of printing.
The other way you can save on toner is to use the “draft” function on your computer and printer settings. This will produce printouts that are suitable for your reading, but not suitable for sending out to other people.
|W|P|114769429971136387|W|P|Purchasing Laser Toner Refills|W|P|venkat@sgdnetworks.comCompatible Laser Toner Cartridges
Recently, there has been a huge legal and investigative battle with people selling “compatible” laser toner cartridges. Often, a distributor will sell their defective, ineffective, or even damaging laser toner cartridges to unsuspecting resellers. These cartridges will make weak prints, cause messy ink spray, and may cause serious damage to your printer. So be sure to buy cartridges from an authorized reseller that the manufacturer audits. Check the manufacturer’s website to obtain a list of authorized resellers.
Beware of laser toner cartridges that are priced way below market standard. Bad or old packaging should also send up a red flag for phony laser toner cartridges.
Finally, if your cartridge runs out of ink too quickly, gives messy prints, or damages your printer, don’t buy from the same retailer again.
This is not to say that all compatible toner cartridges are bunk. But if you’re going to spend tens of dollars on a cartridge, why risk it?
|W|P|114769426331699063|W|P|Buying Laser Toner Cartridges|W|P|venkat@sgdnetworks.comLaser toner is the ink for laser printers. It is an extremely fine synthetic powder (usually plastic) packed into a cartridge. You insert the cartridge into your laser printer according to the manufacturer’s instructions. When the printer goes to print a page, there are several steps to the process:
1. The printer receives an image from your computer. 2. Lasers project the image onto an electromagnetic drum. 3. The drum is charged positively and negatively, and at varying levels of charge, according to the image. 4. The drum attracts the four colors of toner in the cartridge according to the charges the colors are attracted to. The four colors mix to create any of millions of colors. 5. The drum rolls the image onto a page of paper, the page goes through a heating device to melt or burn the color onto the page, and the page is ejected.
This process uses up a lot of laser toner. Typically, a laser toner cartridge will yield a few thousand pages before needing to be replaced. The drum, too, eventually wears out from all the positive and negative charges it gives off, and needs to be replaced every 10,000 – 30,000 pages. Some printers are made with cartridge-and-drum replacement units in mind, while other printers are designed to separate the cartridge and drum. This way, when the cartridge runs out of toner, you don’t have to replace the longer lasting drum with it. This saves you money.
You can buy laser toner from your printer’s manufacturer, a computer supply store, online, or at any of a number of other types of retailers. To save money, you might want to consider buying in bulk.
|W|P|114769422172960209|W|P|A Look at Laser Toners|W|P|venkat@sgdnetworks.comIf you’ve been looking to upgrade your computer video card you’ve probably heard a great deal about PCI Express and SLI. Don’t run out and buy a new computer just yet and take that AGP motherboard you just threw away out of the trash. The truth is you can probably make some simple upgrades to your current computer to get a couple more years of gaming out of it. Of course if you have an extremely slow processor and/or less than an 8x AGP motherboard, you will need to do more than upgrade your graphics card. However, in most cases people’s computers are only a couple of years old and really have plenty of processing power.
The three things to look at are your memory, motherboard, and video card. To get the most out of the more recent games you want to have at least 1GB of RAM. This is a very simple upgrade and only takes a couple of minutes. For more information on upgrading your memory you can visit my website. Second, check to be sure your AGP slot on your current motherboard is 8x. If your memory and motherboard meet these standards you’re in luck. A new video card will probably float you for at least another year, likely two if you get a top of the line card. The thing to remember is that PCI Express is new technology and not nearly as widespread as AGP is. Game companies want to make as much money as possible from each game. For this reason, they will try to make the games play well on the widest array of platforms. When you think about it like this, it is easy to see how AGP will be useful for a while longer. For more information on AGP video cards visit the Video Card review section of my website.
If your motherboard isn’t up to par or your processor is outdated it is time for an upgrade. If you are a do-it-yourselfer like I am, you should look into building your own computer. It’s not as difficult as you might think and can save you a good deal of money.
|W|P|114769418669962158|W|P|Video Cards: Is AGP Dead?|W|P|venkat@sgdnetworks.comSwitch mode power supply contain some large filter capacitors that can hold dangerous charges even if the unit has not been used for several days. Typical values of this type of filter capacitor are 220uf 250volt and 330uf 400volt! If you are going to work on the power supply circuits, it's a good idea to discharge that capacitor first.
There are three ways to discharge the big filter capacitor in a power supply.
1)Discharge it with a screw driver (not recommended).
The reason for not using the screw driver to discharge a capacitor is because
-the printed circuit board or circuitry can be damage due to the spark generated while discharging the high voltage capacitor. I once blowed the power section using this method. However, if you know that the capacitor stored voltage is not too large, you can easily discharge it with a small screw driver.
-if the capacitor holds a heavier charge of electricity. Discharging the capacitor may melt the tip of the screw driver and the copper on the printed circuit board.
-Sometimes a heavier spark may cause small disintegrated solder lead or copper to fly out from the circuit board and may injured your eyes.
2)Place the leads of a socketed 100 watt electric bulb on the leads of the capacitor.
This method had been used by many technicians around the world for the light bulb will act as an indicator to see if the capacitor still holds the charge. If there is a charge the light bulb will light and after discharged the light bulb will goes off.
3)Place the leads of a high wattage resistor on the leads of the capacitor. I use a 2.2k ohm 10 watt resistor to discharge the high voltage capacitor in a switch mode power supplies. It is simple to use and very effective .It takes only couple of seconds to fully discharge the capacitor.
Conclusion
I strongly suggest for those who use screw driver to discharge a capacitor to swift to the second and third method as these is the safest method to protect the circuit and most importantly is yourself.
|W|P|114769415109704635|W|P|The Right Way To Discharge Capacitor In Switch Mode Power Supplies|W|P|venkat@sgdnetworks.comLaptop Notebook – Your Portable Office
In much of today’s business world, portability and mobility are the keys to success. Having a laptop notebook computer provides business men and women with portable computing capability, and these notebooks help them take their mobile business functionality to a new level.
Notebook Computers Provide Portability to Today’s Workers
Advances in computer electronics have brought us to the point where we can take these mobile and portable notebook computers all over the world, conduct business from home with our notebooks, and even connect our laptops to a computer network in Los Angeles from a coffee shop in Atlanta. These notebooks have changed how we conduct business, and in order to keep up with these changes more and more professionals and companies are making the investment of notebooks for themselves and their mobile workforce.
For the small company or individual business owner, the investment needed to buy notebooks and move into the world of portability and mobility doesn’t have to be enormous. Some companies, especially larger ones, will make the decision to invest big money in the top of the line notebook computer. Other companies will choose to make a lesser but equally valuable investment in discount or used laptops. As long as the laptop computers meet the mobile business needs, making the smaller investment in notebooks works out great for companies or individuals who are conducting mobile and portable business on a tighter budget.
Want to read more about Electronics? Visit electronicsme.net or electronicsme.com for the latest articles on televisions, digital still cameras, and notebook computers.
Electronicsme: Where electronics are made easy!
|W|P|114769411454711405|W|P|Laptop Notebook - Inexpensive Business Laptops|W|P|venkat@sgdnetworks.comComputers and their accompanying printers were huge years ago. In the past toner reservoirs and toner cartridges were used instead of ink cartridges like those used now. It was difficult to fill a toner cartridge and it was very messy.
Toner cartridges were an improvement. Print wheels and ribbons were used in some printers. Computers are now more compact and the printers do more than just print in some cases. Printer cartridges now have self-contained reservoirs. Refilling some printer cartridges now is not as messy as adding toner was.
Printer cartridges are available in two types. Primarily Hewlett-Packard and Epson printers used the first type the Piezo Electric. An applied electric current is put to a small crystal causing it to expand approximately every five microseconds (20,000 per second).
The inkjet ink squirts out through the print heads very fast and very precisely because of this expansion. Because Piezo Electric has fewer print heads than bubble jet/thermal printers it can do more precise action and tends to last longer. Bubble jet cartridges heats the ink rapidly into a bubble and then squirts it through ink nozzles thousands of times per second.
Bubble jet printers are less noisy than the Piezo based printers. You can expect really high resolution color printing from it. Inkjet has ink squirted through the nozzles as they move over a variety of media, not mega pixel method. Various colored liquid ink is squirted at the paper to create an image. The page gets scanned by the print head horizontally by a motor assembly that rolls the paper vertically.
A strip of an image is printed and the paper moves toward the next step. It not only prints a strip across the page it also prints vertical rows of pixels in each pass for speed. There are a number of types of inkjet technology. Ink in small drops are squirted onto the paper through tiny nozzles in drop on demand (DOD).
It resembles turning a hose off and on 5,000 times a second. How much ink is dropped on the page and which nozzle fires and when is controlled by the driver software program. The ink may smudge after printing is one problem with inkjet technology. With the development of new ink compositions, this is progressing.
Ink is discharged onto the paper in the Thermal Technology of printing. This process has three stages. In stage one the squirt begins when the ink is heated to create a bubble. When the pressure is initiated the bubble breaks and
The resulting vacuum draws out the ink from the reservoir to replace what was ejected. Printers used to be costly because the print heads that would imprint the image on the paper was within the printer. Printers are cheap now but the expense comes when you need to buy cartridges.
You could almost conclude it would almost be worth it to buy a new printer instead of the cartridges because the price of the cartridges can be more than the cost of the most basic inkjet printers.
Though the current price of cartridges is expensive the complex technology they contain will end up being cheaper in the long run than it would be to continually replace printer heads.
Now print heads are contained within the cartridges themselves. It's exciting because if you use the correct cartridges for your printer you could have it for a very long time. Color cartridges work the same way as black cartridges by squirting the ink through tiny nozzles onto the paper in horizontal strips while they move across the page.
There are three individual reservoirs in color cartridges, one is filled with cyan, the other with magenta, and the other with yellow ink. The quality of the image can be influenced by a lot of things. The quality of the paper can affect the image you get. The image you get can be affected by both brightness and absorption of the ink.
Brightness indicates the vividness of the print image and absorption is how effectively the paper absorbs the ink. When using an inkjet printer, it is best to use paper specifically designed for its use. The best possible image can be possible with the use of the proper paper.
Things that can affect your printing project are display properties settings and/or printer settings. You may want to leave your documents alone to dry for awhile depending on the paper you use and your printer. Most printers have an ink saver setting that puts out less ink which will allow documents to dry faster. You should have knowledge of how your printer operates.
|W|P|114769407368601020|W|P|Ink Cartridges - A Humble Beginning|W|P|venkat@sgdnetworks.comFor Video cards - Most PC video cards these days are AGP. But you COULD be working with PCI, or PCI express. If you're not sure which you have (more then 75% of the time it will be AGP) consult your motherboard manual. If your video card is AGP, you should see a slot smaller then the other slots on your board, and it will be a different color. You can likely also tell your video card if it has a GPU (a processor with a fan on top of it) or a video card company printed on it like Nvidia or Geforce.
To take out your video card in order to switch it for a newer one, or if it simply is not working, remove the screw first that holds it to the case. DO NOT ATTEMPT TO REMOVE THE CARD UNTIL YOU HAVE UNSCREWED IT. You will damage, maybe even destroy your card, and you may damage your AGP, PCI or PCI express slot as well. Your board may then have a simple switch that holds the socket down. Flick this switch up. After the scrue is removed, and the switch is flicked up, pull the card away from the board. Pull it on one side first so when it comes out it comes out on a slant, kind of like a car reversing. It should come out quite easily. To put in a new card, make sure the card you're putting in is properly lined up in the slot, then press the card into the slot. If it dosen't seem to be going in, you may be putting it in the wrong way. The pathways on the one side of the card should be the side that goes into the motherboard slot (these pathways looking like small lines going up one side of the card). Once the card sinks in with almost a click (like RAM), flick the switch down and scrue the card into the place you unscrued it. Start up your PC, make sure the card is working, then put your case back on.
Sound card - Sound cards are pretty easy, and the method for these can be used for any other card, such as network cards and the like (assuming they are all PCI. PCI are the black slots on your board). For installing/removing a PCI card, just unscrue it from the board, pull it out, then put the new one in, and scrue it in. Pretty easy. If you are having troubles, make sure the lines running up one side of the card is the side going into the slot. If you still have troubles, try turning the card around (but still make sure the pathways are facing the slot).
|W|P|114769403876551364|W|P|Upgrading, Adding or Removing a Video Card, Sound Card, or Other AGP/PCI Card|W|P|venkat@sgdnetworks.com