Barcode scanners can be hugely simple devices composed of an easy source, a photograph diode along with a simple decoder or complex CCD or camera based scanners. Find out how barcode scanners work and ways to scan bluetooth barcode right into a computer.
You can find currently four various kinds of barcode scanners available. Each utilizes 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 contain an easy source along with a photo diode which are placed next to each other inside the tip of any pen or wand. To learn a barcode, you drag the tip from the pen across each of the bars in the steady even motion. The photo diode measures the concentration of the light reflected back from the source of light and generates a waveform which is used to appraise the widths in the bars and spaces within the barcode. Dark bars inside the barcode absorb light and white spaces reflect light so the voltage waveform generated by the photo diode is undoubtedly an exact duplicate of your bar and space pattern within the barcode. This waveform is decoded from the scanner inside a manner the same as the way Morse code dots and dashes are decoded.
Laser scanners work exactly the same as pen type readers other than they prefer a laser beam because the light source and typically employ either a reciprocating mirror or a rotating prism to scan the laser beam to and fro over the barcode. Just just like with all the pen type reader, a photograph diode is used to measure the intensity of the light reflected back from the barcode. Both in pen readers and laser scanners, light emitted with the reader is tuned to a specific frequency and also the photo diode is designed to detect only this same frequency light.
Pen type readers and laser scanners are available with different resolutions to enable them to read barcodes of numerous sizes. The scanner resolution is measured by the actual size of the dot of light emitted through the reader. The dot of light should be comparable to or slightly small compared to the narrowest element width (“X” dimension). In case the dot is wider in comparison to the width from the narrowest bar or space, then your dot will overlap 2 or more bars at any given time thereby resulting in the scanner to struggle to distinguish clear transitions between bars and spaces. If the dot is way too small, then any spots or voids within the bars could be misinterpreted as light areas also making barcode companion unreadable. One of the most frequently used X dimension is 13 mils (roughly 4 printer dots on the 300 DPI printer). Simply because this X dimension is so small, it is very crucial that the barcode is created by using a program that can cause high res graphics (like B-Coder).
CCD (Charge Coupled Device) readers use a wide range of a huge selection of tiny light sensors lined up consecutively within the head from the reader. Each sensor can be considered to be just one photo diode that measures the intensity of the light immediately looking at it. Every individual light sensor inside the CCD reader is extremely small and seeing as there are a huge selection of sensors arranged in a row, a voltage pattern just like the pattern inside a barcode is generated inside the reader by sequentially measuring the voltages across each sensor inside 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 through the barcode whereas pen or laser scanners are measuring reflected light of a specific frequency originating from the scanner itself.
The 4th and newest sort of barcode reader on the market today are camera based readers which use a little video camera to capture a picture of the barcode. Your reader then uses sophisticated digital image processing strategies to decode the barcode. Video cameras make use of the same CCD technology like a CCD barcode reader although instead of possessing a single row of sensors, a video camera has a huge selection of rows of sensors arranged within a two dimensional array so they can generate a photo.
The factors that make a barcode readable are: a satisfactory print contrast in between the light and dark bars and getting all bar and space dimensions inside the tolerances to the symbology. It is also important to have sharp bar edges, few or no spots or voids, an easy surface and clear margins or “quiet zones” at either end in the printed symbol.
All application programs support barcode reading so long as you get the right equipment. Barcode readers can be purchased 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 PC and they also offer a pigtail connector to help you plug in your keyboard at the same time. Once you scan a barcode with the keyboard wedge barcode reader, the data enters into the computer in the same way whether it were typed in on the keyboard. It is then extremely easy to interface the barcode reader for any application which is written to just accept keyboard data.
The keyboard wedge interface is quite simple however it possesses a few drawbacks. Should you swipe a barcode, the cursor has to be inside the correct input field inside the correct application otherwise you find yourself reading barcode data into whatever application has the focus. This may cause a variety of potential issues obviously. The keyboard output also is limited for the reason that you are unable to modify the information by any means before sending it in to the program that may be to obtain the info. For instance, when you required to parse a barcode message into multiple pieces or remove some of a barcode message or add in the date or time stamp you will not be able to having a normal keyboard wedge reader.
One other possible output option is to find a barcode reader with an RS232 or “Serial” interface. With these kinds of barcode readers, you connect your reader to an available serial 65dexqpky on the back of your PC. You might then require a program referred to as a “Software Wedge” to take the data from the barcode reader and feed it for the application that you want the data to look. The disadvantage of this method is that it might be a more technical however you gain much more power over where and how your data ultimately ends up if you read barcode sled.
Our WinWedge product lines are designed just for this purpose. WinWedge is surely an executable program that may 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 with the incoming serial data). With WinWedge, you are able to control exactly where the information goes in the prospective application and you can also perform all kinds of modifications around the data before it is actually sent to the applying including parsing or translating the info as well as adding additional keystrokes or date and time stamps on the data.
WinWedge is extremely easy to use and was designed to have you up and running sending and receiving serial data from inside your application in a short while. Because WinWedge can pass data using DDE, you are able to set your application approximately insure how the barcode data always goes where it should really go and you will have the application running in the background still accept barcode input while you run a few other program in the foreground. WinWedge is without question the most robust approach to interface a barcode reader to your PC using the least amount of effort.