Barcode scanners can be very simple devices made up of an easy source, a picture diode plus a simple decoder or complex CCD or camera based scanners. Understand how barcode scanners work and how to scan bluetooth barcode into a computer.
You will find currently four different types of barcode scanners available. Each utilizes a slightly different technology for reading and decoding a barcode. You will find pen type readers (i.e. barcode wands), laser scanners, CCD readers and camera based readers.
Pen type readers include an easy source as well as a photo diode which can be placed next to each other from the tip of your pen or wand. To see a barcode, you drag the tip of your pen across each of the bars within a steady even motion. The photo diode measures the power of the sunshine reflected back from the source of light and generates a waveform that is used to look at the widths of your bars and spaces inside the barcode. Dark bars inside the barcode absorb light and white spaces reflect light to ensure the voltage waveform generated from the photo diode is an exact duplicate of your bar and space pattern in the barcode. This waveform is decoded from the scanner in a manner like the way Morse code dots and dashes are decoded.
Laser scanners work much the same way as pen type readers other than they prefer a laser beam as being the light source and typically employ either a reciprocating mirror or even a rotating prism to scan the laser beam backwards and forwards over the barcode. Just exactly like using the pen type reader, a photo diode is utilized to measure the concentration of light reflected back through the barcode. In pen readers and laser scanners, the lighting emitted with the reader is tuned to a specific frequency and the photo diode is made to detect only this same frequency light.
Pen type readers and laser scanners are available with different resolutions to allow them to read barcodes of several sizes. The scanner resolution is measured by the actual size of the dot of light emitted with the reader. The dot of light ought to be equal to or slightly small compared to the narrowest element width (“X” dimension). In case the dot is wider compared to width from the narrowest bar or space, then this dot will overlap two or more bars at a time thereby causing the scanner to struggle to distinguish clear transitions between bars and spaces. When the dot is just too small, then any spots or voids in the bars may be misinterpreted as light areas also making barcode companion unreadable. By far the most popular X dimension is 13 mils (roughly 4 printer dots over a 300 DPI printer). Simply because this X dimension is very small, it is quite critical that the barcode is made with a program that creates high definition graphics (like B-Coder).
CCD (Charge Coupled Device) readers use an array of a huge selection of tiny light sensors lined up in a row from the head in the reader. Each sensor can be regarded as just one photo diode that measures the concentration of the sunshine immediately looking at it. Every person light sensor inside the CCD reader is quite small, and because there are countless sensors arranged consecutively, a voltage pattern just like the pattern inside a barcode is generated within the reader by sequentially measuring the voltages across each sensor inside the row. The important difference between a CCD reader along with a pen or laser scanner is the CCD reader is measuring emitted ambient light from your barcode whereas pen or laser scanners are measuring reflected light of any specific frequency originating from the scanner itself.
The 4th and newest kind of barcode reader available today are camera based readers designed to use a little camera to capture a photo of any barcode. The reader then uses sophisticated digital image processing methods to decode the barcode. Video cameras make use of the same CCD technology as in a CCD barcode reader other than instead of having a single row of sensors, a video camera has countless rows of sensors arranged inside a two dimensional array so they can generate an image.
The factors which make a barcode readable are: a satisfactory print contrast in between the light and dark bars and getting all bar and space dimensions throughout the tolerances for the symbology. Additionally it is helpful to have sharp bar edges, few or no spots or voids, an effortless surface and clear margins or “quiet zones” at either end from the printed symbol.
All application programs support barcode reading providing you have the right equipment. Barcode readers are offered with two types of output – either “keyboard wedge” output or RS232 output. The barcode readers with keyboard wedge output plug straight into the keyboard port on your hard drive additionally they provide a pigtail connector so that you can connect your keyboard concurrently. Whenever you scan a barcode using the keyboard wedge barcode reader, your data enters into your computer just as whether it were typed in in the keyboard. This makes it extremely an easy task to interface the barcode reader to any application that may be written to just accept keyboard data.
The keyboard wedge interface is very simple however it possesses a few drawbacks. Should you swipe a barcode, the cursor should be inside the correct input field within the correct application otherwise you end up reading barcode data into whatever application has got the focus. This may cause all sorts of potential problems as you can imagine. The keyboard output is also limited in this you are unable to modify the data in any way before sending it into the program which is to get your data. By way of example, when you needed to parse a barcode message into multiple pieces or remove a number of a barcode message or add within a date or time stamp you will be unable to using a normal keyboard wedge reader.
The other possible output option is to get a barcode reader with an RS232 or “Serial” interface. With most of these barcode readers, you connect your reader to a available serial 65dexqpky on the back of your PC. You would then want a program termed as a “Software Wedge” to take the data from the barcode reader and feed it to the application the place you want the info to travel. The disadvantage to this strategy is it is a bit more technical however, you gain a lot more power over where and how your information winds up when you read barcode sled.
Our WinWedge product line is designed just for this purpose. WinWedge is definitely an executable program that may pass serial data back and forth to 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 specifically where the info goes into the prospective application and you could also perform all sorts of modifications around the data before it can be shipped to the application including parsing or translating the information as well as adding additional keystrokes or date and time stamps for the data.
WinWedge is extremely simple to use and was created to do you have working sending and receiving serial data straight from inside your application within a matter of minutes. Because WinWedge can pass data using DDE, you may set your application around insure that the barcode data always goes where it should certainly go and you can also have your application running in the background still accept barcode input whilst you run some other program from the foreground. WinWedge is without question the most robust method to interface a barcode reader to a PC with the least level of effort.