Barcode scanners can be hugely simple devices consisting of an easy source, a photo diode along with a simple decoder or complex CCD or camera based scanners. Learn how barcode scanners work and the ways to scan bluetooth barcode in to a computer.
There are currently four different kinds of barcode scanners available. Each works with a slightly different technology for reading and decoding a barcode. There are actually pen type readers (i.e. barcode wands), laser scanners, CCD readers and camera based readers.
Pen type readers comprise of an easy source as well as a photo diode that are placed next to one another in the tip of any pen or wand. To learn a barcode, you drag the tip of your pen across every one of the bars inside a steady even motion. The photo diode measures the power of the lighting reflected back through the source of light and generates a waveform that is used to study the widths in the bars and spaces inside the barcode. Dark bars from the barcode absorb light and white spaces reflect light in order that the voltage waveform generated through the photo diode is undoubtedly an exact duplicate of your bar and space pattern inside the barcode. This waveform is decoded with the scanner within a manner just like the way Morse code dots and dashes are decoded.
Laser scanners work exactly the same as pen type readers except that they utilize a laser beam as being the source of light and typically employ either a reciprocating mirror or perhaps a rotating prism to scan the laser beam back and forth over the barcode. Just exactly like with all the pen type reader, a photograph diode is utilized to appraise the concentration of light reflected back from the barcode. Both in pen readers and laser scanners, the lighting emitted from the reader is tuned to some specific frequency and the photo diode is designed to detect only this same frequency light.
Pen type readers and laser scanners can be purchased with some other resolutions to allow them to read barcodes of different sizes. The scanner resolution is measured by the actual size of the dot of light emitted by the reader. The dot of light should be comparable to or slightly smaller compared to the narrowest element width (“X” dimension). If the dot is wider compared to the width in the narrowest bar or space, then a dot will overlap two or more bars at one 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 could be misinterpreted as light areas also making wearable scanner unreadable. By far the most popular X dimension is 13 mils (roughly 4 printer dots on a 300 DPI printer). As this X dimension is really small, it is rather critical that the barcode is made by using a program that can cause high res graphics (like B-Coder).
CCD (Charge Coupled Device) readers use a multitude of numerous tiny light sensors lined up in a row from the head from the reader. Each sensor may be looked at as just one photo diode that measures the concentration of the light immediately before it. Each individual light sensor in the CCD reader is incredibly small, and because there are hundreds of sensors arranged consecutively, a voltage pattern identical to the pattern in the barcode is generated from the reader by sequentially measuring the voltages across each sensor from the row. The key distinction between a CCD reader plus a pen or laser scanner is that the CCD reader is measuring emitted ambient light from your barcode whereas pen or laser scanners are measuring reflected light of your specific frequency caused by the scanner itself.
Your fourth and newest kind of barcode reader currently available are camera based readers that use a small camera to capture a photo of your barcode. The reader then uses sophisticated digital image processing solutions to decode the barcode. Video cameras use the same CCD technology as with a CCD barcode reader although instead of developing a single row of sensors, a youtube video camera has countless rows of sensors arranged in the two dimensional array in order to generate a photo.
The factors which make a barcode readable are: a satisfactory print contrast involving the light and dark bars and achieving all bar and space dimensions inside the tolerances for the symbology. Also, it is beneficial 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 so long as you possess the right equipment. Barcode readers are offered with 2 kinds of output – either “keyboard wedge” output or RS232 output. The barcode readers with keyboard wedge output plug straight into the keyboard port on your personal computer plus they give a pigtail connector to be able to plug in your keyboard simultaneously. When you scan a barcode together with the keyboard wedge barcode reader, the information explores your computer just like whether it were typed in on the keyboard. This will make it extremely easy to interface the barcode reader to the application which is written to simply accept keyboard data.
The keyboard wedge interface is incredibly simple however it possesses a few drawbacks. Should you swipe a barcode, the cursor has to be in the correct input field inside the correct application otherwise you find yourself reading barcode data into whatever application provides the focus. This will cause a number of potential problems as you can imagine. The keyboard output is also limited in this you are unable to modify the data by any means before sending it in the program which is to get the information. For example, when you needed to parse a barcode message into multiple pieces or remove several of a barcode message or add in a date or time stamp you would probably not be able to using a normal keyboard wedge reader.
The other possible output option is to buy a barcode reader with an RS232 or “Serial” interface. With these sorts of barcode readers, you connect the reader for an available serial 65dexqpky on the rear of your computer. You will then require a program known as a “Software Wedge” to take the data from your barcode reader and feed it for the application the place you want your data to go. The disadvantage of this approach is it is a little more advanced nevertheless you gain a lot more control of how and where your computer data winds up when you read barcode sled.
Our WinWedge product lines are designed just for this purpose. WinWedge is an executable program that can pass serial data back and forth for some 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 are able to control specifically where the data goes into the target application and you could also perform a number of modifications in the data before it is shipped to the applying including parsing or translating the information along with adding additional keystrokes or date and time stamps for the data.
WinWedge is incredibly simple to operate and is designed to perhaps you have ready to go sending and receiving serial data straight from in your own application with a matter of minutes. Because WinWedge can pass data using DDE, you can set your application around insure that the barcode data always goes where it should really go and you can also have the application running inside the background still accept barcode input whilst you run various other program from the foreground. WinWedge is without question the most robust approach to interface a barcode reader to your PC with the least volume of effort.