Barcode scanners can be very simple devices consisting of a mild source, a picture diode as well as a simple decoder or complex CCD or camera based scanners. Find out how barcode scanners work and ways to scan barcode scanner in to a computer.
You can find currently four several types of barcode scanners available. Each works with 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 contain an easy source as well as a photo diode which can be placed next to each other within the tip of any pen or wand. To learn a barcode, you drag the tip of your pen across every one of the bars in a steady even motion. The photo diode measures the intensity of the light reflected back from the light source and generates a waveform which is used to appraise the widths of the bars and spaces from the barcode. Dark bars from the barcode absorb light and white spaces reflect light so that the voltage waveform generated through the photo diode is surely an exact duplicate in the bar and space pattern from the barcode. This waveform is decoded by the scanner in a manner like the way Morse code dots and dashes are decoded.
Laser scanners work exactly the same as pen type readers although they prefer a laser beam because the light source and typically employ either a reciprocating mirror or perhaps a rotating prism to scan the laser beam back and forth over the barcode. Just similar to together with the pen type reader, a photograph diode is commonly used to appraise the power of light reflected back in the barcode. Within both pen readers and laser scanners, the lighting emitted from the reader is tuned to a specific frequency as well as the photo diode is designed to detect only this same frequency light.
Pen type readers and laser scanners can be purchased with assorted resolutions to allow them to read barcodes of numerous sizes. The scanner resolution is measured by the size of the dot of light emitted from the reader. The dot of light must be comparable to or slightly smaller compared to the narrowest element width (“X” dimension). In the event the dot is wider than the width in the narrowest bar or space, then the dot will overlap several bars at one time thereby causing the scanner to not be able to distinguish clear transitions between bars and spaces. In case the dot is too small, then any spots or voids within the bars may be misinterpreted as light areas also making barcode companion unreadable. One of the most commonly used X dimension is 13 mils (roughly 4 printer dots over a 300 DPI printer). As this X dimension is very small, it is quite critical that the barcode is generated having a program that creates high resolution graphics (like B-Coder).
CCD (Charge Coupled Device) readers use a wide range of a huge selection of tiny light sensors arranged in a row within the head from the reader. Each sensor could be thought of as a single photo diode that measures the power of the sunshine immediately in front of it. Each individual light sensor inside the CCD reader is incredibly small and since there are countless sensors arranged consecutively, a voltage pattern identical to the pattern in the barcode is generated inside the reader by sequentially measuring the voltages across each sensor from the row. The most important difference between a CCD reader plus 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 caused by the scanner itself.
The 4th and newest sort of barcode reader currently available are camera based readers designed to use a small camera to capture an image of the barcode. Your reader then uses sophisticated digital image processing methods to decode the barcode. Video cameras take advantage of the same CCD technology like a CCD barcode reader although as opposed to having a single row of sensors, a youtube video camera has a huge selection of rows of sensors arranged inside a two dimensional array to enable them to generate a photo.
The factors that make a barcode readable are: a sufficient print contrast involving the light and dark bars and achieving all bar and space dimensions throughout the tolerances for the symbology. Additionally it is beneficial to have sharp bar edges, few or no spots or voids, a smooth surface and clear margins or “quiet zones” at either end of your printed symbol.
All application programs support barcode reading as long as you have the right equipment. Barcode readers are available with 2 types of output – either “keyboard wedge” output or RS232 output. The barcode readers with keyboard wedge output plug directly into the keyboard port on your hard drive and they also offer a pigtail connector to be able to connect your keyboard concurrently. Whenever you scan a barcode together with the keyboard wedge barcode reader, the data enters into the computer just as if this were typed in in the keyboard. It is then extremely easy to interface the barcode reader to the application which is written to simply accept keyboard data.
The keyboard wedge interface is very simple however it has a few drawbacks. Should you swipe a barcode, the cursor should be from the correct input field inside the correct application otherwise you find yourself reading barcode data into whatever application has the focus. This will cause a number of potential issues as you can imagine. The keyboard output is also limited in that you are unable to modify the information at all before sending it into the program that is certainly to obtain the information. By way of example, when you required to parse a barcode message into multiple pieces or remove a few of a barcode message or add within a date or time stamp you will be unable to having a normal keyboard wedge reader.
One other possible output option is to find a barcode reader by having an RS232 or “Serial” interface. With most of these barcode readers, you connect your reader with an available serial 65dexqpky on the rear of your PC. You will then want a program called a “Software Wedge” to accept data in the barcode reader and feed it to the application in which you want your data to travel. The problem with this process is it is a little more advanced however you gain considerably more control of how and where your computer data ends up if you read barcode sled.
Our WinWedge product lines are designed just for this specific purpose. WinWedge is surely an executable program that could pass serial data back and forth with other programs using either DDE (Dynamic Data Exchange) or by converting incoming serial data to keystrokes (i.e. it stuffs the keyboard buffer using the incoming serial data). With WinWedge, you may control exactly where the info goes in the target application and you could also perform all kinds of modifications about the data before it can be shipped to the application form including parsing or translating the information along with adding additional keystrokes or date and time stamps towards the data.
WinWedge is incredibly user friendly and is designed to have you ever operational sending and receiving serial data right from in your own application in just a short while. Because WinWedge can pass data using DDE, it is possible to set the application around insure the barcode data always goes where it should certainly go and you can also provide your application running from the background still accept barcode input whilst you run some other program from the foreground. WinWedge is undoubtedly one of the most robust strategy to interface a barcode reader to some PC together with the least quantity of effort.