Barcode scanners can be extremely simple devices made up of a mild source, a picture diode plus a simple decoder or complex CCD or camera based scanners. Learn how barcode scanners work and ways to scan barcode reader in a computer.
There are currently four several types of barcode scanners available. Each uses a slightly different technology for reading and decoding a barcode. You can find pen type readers (i.e. barcode wands), laser scanners, CCD readers and camera based readers.
Pen type readers comprise of a light source along with a photo diode which are placed next to each other inside the tip of a pen or wand. To learn a barcode, you drag the tip of your pen across every one of the bars within a steady even motion. The photo diode measures the concentration of the lighting reflected back from the light source and generates a waveform that is utilized to look at the widths of your bars and spaces inside the barcode. Dark bars within the barcode absorb light and white spaces reflect light to ensure the voltage waveform generated with the photo diode is an exact duplicate of your bar and space pattern in the barcode. This waveform is decoded with the scanner in the manner similar to the way Morse code dots and dashes are decoded.
Laser scanners work exactly the same way as pen type readers although they utilize a laser beam because the light source and typically employ either a reciprocating mirror or a rotating prism to scan the laser beam forward and backward throughout the barcode. Just similar to with all the pen type reader, a photo diode can be used to appraise the concentration of the sunshine reflected back in the barcode. In pen readers and laser scanners, light emitted with the reader is tuned to some specific frequency along with the photo diode is made to detect only this same frequency light.
Pen type readers and laser scanners are available with assorted resolutions to enable them to read barcodes of several sizes. The scanner resolution is measured by how big the dot of light emitted from the reader. The dot of light needs to be similar to or slightly small compared to the narrowest element width (“X” dimension). In case the dot is wider compared to the width of the narrowest bar or space, then the dot will overlap several bars at any given time thereby inducing the scanner to struggle to distinguish clear transitions between bars and spaces. If the dot is simply too small, then any spots or voids in the bars may be misinterpreted as light areas also making barcode companion unreadable. The most popular X dimension is 13 mils (roughly 4 printer dots on the 300 DPI printer). Because this X dimension is indeed small, it is extremely critical that the barcode is created with a program that creates high res graphics (like B-Coder).
CCD (Charge Coupled Device) readers use a wide range of countless tiny light sensors arranged in a row inside the head from the reader. Each sensor might be thought of as just one photo diode that measures the power of the lighting immediately facing it. Each individual light sensor inside the CCD reader is incredibly small and as there are hundreds of sensors lined up in a row, a voltage pattern identical to the pattern inside a barcode is generated inside the reader by sequentially measuring the voltages across each sensor in the row. The key distinction between a CCD reader and a pen or laser scanner is the fact that CCD reader is measuring emitted ambient light in the barcode whereas pen or laser scanners are measuring reflected light of a specific frequency originating from the scanner itself.
The 4th and newest form of barcode reader available today are camera based readers that utilize a little camera to capture a photo of the barcode. The reader then uses sophisticated digital image processing strategies to decode the barcode. Video cameras utilize the same CCD technology like in a CCD barcode reader other than instead of using a single row of sensors, a relevant video camera has a huge selection of rows of sensors arranged inside a two dimensional array so that they can generate a photo.
The factors that will make a barcode readable are: a satisfactory print contrast in between the light and dark bars and achieving all bar and space dimensions inside the tolerances for that symbology. Additionally it is helpful to have sharp bar edges, few or no spots or voids, an easy surface and clear margins or “quiet zones” at either end of your printed symbol.
All application programs support barcode reading providing you possess the right equipment. Barcode readers can be found with two kinds of output – either “keyboard wedge” output or RS232 output. The barcode readers with keyboard wedge output plug into the keyboard port on your PC plus they provide a pigtail connector to enable you to connect your keyboard as well. When you scan a barcode with all the keyboard wedge barcode reader, the data enters into the computer in the same way whether it were typed in in the keyboard. It is then extremely easy to interface the barcode reader to any application which is written to take keyboard data.
The keyboard wedge interface is extremely simple however it possesses a few drawbacks. Should you swipe a barcode, the cursor must be inside the correct input field inside the correct application otherwise you wind up reading barcode data into whatever application has the focus. This will cause a number of potential issues obviously. The keyboard output is also limited in that you can not modify the data at all before sending it in the program which is to get your data. By way of example, when you necessary to parse a barcode message into multiple pieces or remove a number of a barcode message or add inside a date or time stamp you would probably struggle to having a normal keyboard wedge reader.
Other possible output option is to buy a barcode reader with the RS232 or “Serial” interface. With these kinds of barcode readers, you connect the reader to an available serial 65dexqpky on the back of your computer. You would probably then need a program termed as a “Software Wedge” to accept data in the barcode reader and feed it for the application in which you want your data to visit. The problem with this process is that it might be a more complicated however you gain far more control over where and how your data winds up whenever you read moto z barcode.
Our WinWedge product line is designed just for this reason. WinWedge is an executable program that may pass serial data forward and backward to many other programs using either DDE (Dynamic Data Exchange) or by converting incoming serial data to keystrokes (i.e. it stuffs the keyboard buffer together with the incoming serial data). With WinWedge, it is possible to control specifically where your data goes in the marked application and you could also perform a number of modifications in the data before it is sent to the applying including parsing or translating the info along with adding additional keystrokes or date and time stamps towards the data.
WinWedge is quite user friendly and was designed to do you have up and running sending and receiving serial data from in your own application in a couple of minutes. Because WinWedge can pass data using DDE, you can set your application as much as insure the barcode data always goes where it is supposed to go and you will also have your application running within the background still accept barcode input whilst you run another program inside the foreground. WinWedge is without question probably the most robust method to interface a barcode reader to your PC together with the least amount of effort.