Barcode scanners can be quite simple devices comprised of an easy source, a photograph diode and a simple decoder or complex CCD or camera based scanners. Find out how barcode scanners work and ways to scan bluetooth barcode in to a computer.
You will find currently four several types 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 include a light source and a photo diode that are placed next to one another within the tip of your pen or wand. To see a barcode, you drag the tip of your pen across all the bars within a steady even motion. The photo diode measures the power of the sunshine reflected back from the light source and generates a waveform that is utilized to measure the widths from the bars and spaces in the barcode. Dark bars inside the barcode absorb light and white spaces reflect light in order that 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 within a manner just like the way Morse code dots and dashes are decoded.
Laser scanners work exactly the same way as pen type readers except that they normally use a laser beam since the light source and typically employ either a reciprocating mirror or even a rotating prism to scan the laser beam to and fro all over the barcode. Just similar to with all the pen type reader, a picture diode is commonly used to study the intensity of the lighting reflected back from your barcode. Both in pen readers and laser scanners, the sunshine emitted from 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 can be acquired with assorted resolutions to enable them to read barcodes of different sizes. The scanner resolution is measured by the dimensions of the dot of light emitted from the reader. The dot of light must be equivalent to or slightly smaller compared to the narrowest element width (“X” dimension). If the dot is wider in comparison to the width from the narrowest bar or space, then a dot will overlap a couple of bars at one time thereby creating the scanner to struggle to distinguish clear transitions between bars and spaces. In case the dot is too small, then any spots or voids inside the bars may be misinterpreted as light areas also making wearable scanner unreadable. One of the most frequently used X dimension is 13 mils (roughly 4 printer dots with a 300 DPI printer). Since this X dimension is so small, it is very crucial that the barcode is produced having a program that creates high definition graphics (like B-Coder).
CCD (Charge Coupled Device) readers use a wide range of countless tiny light sensors lined up in a row inside the head from the reader. Each sensor can be looked at as one particular photo diode that measures the intensity of light immediately before it. Each individual light sensor inside the CCD reader is extremely small and as there are countless sensors arranged in a row, a voltage pattern identical to the pattern inside a barcode is generated in the reader by sequentially measuring the voltages across each sensor inside the row. The key distinction between a CCD reader along with a pen or laser scanner is the CCD reader is measuring emitted ambient light in the barcode whereas pen or laser scanners are measuring reflected light of any specific frequency originating from the scanner itself.
Your fourth and newest sort of barcode reader now available are camera based readers that use a tiny camera to capture a picture of a barcode. Your reader then uses sophisticated digital image processing strategies to decode the barcode. Video cameras use the same CCD technology like in a CCD barcode reader other than as an alternative to having a single row of sensors, a relevant video camera has countless rows of sensors arranged within a two dimensional array to enable them to generate a picture.
The standards that can make a barcode readable are: a satisfactory print contrast in between the light and dark bars and having all bar and space dimensions within the tolerances to the symbology. Also, it is important to have sharp bar edges, few or no spots or voids, an even surface and clear margins or “quiet zones” at either end of the printed symbol.
All application programs support barcode reading provided that you possess the right equipment. Barcode readers can be purchased with 2 types of output – either “keyboard wedge” output or RS232 output. The barcode readers with keyboard wedge output plug into the keyboard port on your personal computer and they also provide a pigtail connector so that you can connect your keyboard at the same time. When you scan a barcode using the keyboard wedge barcode reader, the data enters into the computer equally as whether it were typed in around the keyboard. It is then extremely very easy to interface the barcode reader to any application which is written to simply accept keyboard data.
The keyboard wedge interface is incredibly simple however it features a few drawbacks. If you swipe a barcode, the cursor needs to be within the correct input field inside the correct application otherwise you wind up reading barcode data into whatever application has the focus. This can cause all sorts of potential problems obviously. The keyboard output is also limited in this you cannot modify your data at all before sending it in to the program that is to get the information. For instance, in the event you necessary 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 struggle to by using a normal keyboard wedge reader.
Other possible output option is to get a barcode reader having an RS232 or “Serial” interface. With these types of barcode readers, you connect the reader with an available serial 65dexqpky on the rear of your PC. You might then need to have a program called a “Software Wedge” to take the data through the barcode reader and feed it to the application the place you want your data to go. The disadvantage of this process is it might be a more complex nevertheless, you gain much more control of how and where your computer data winds up if you read barcode sled.
Our WinWedge product line is designed just for this purpose. WinWedge is surely an executable program that may pass serial data forward and backward 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 can control precisely where the data goes in the target application and you can also perform all sorts of modifications in the data before it really is sent to the application form including parsing or translating the info and also adding additional keystrokes or date and time stamps for the data.
WinWedge is extremely user friendly and was designed to do you have working sending and receiving serial data straight from in your application in a short while. Because WinWedge can pass data using DDE, you are able to set the application around insure how the barcode data always goes where it is supposed to go and you may have your application running inside the background and still accept barcode input as you run a few other program in the foreground. WinWedge is undoubtedly one of the most robust strategy to interface a barcode reader to a PC together with the least level of effort.