Bar code scanners
- Categories:Expert Answer
- Time of issue:2020-07-09 00:00:00
Bar code scanners are often referred to as the bar code scanning gun / reader, which is used to read the bar code contains information of the scanner device. The structure of bar code scanner / bar code scanning gun is usually the following parts: light source, receiving device, photoelectric conversion unit, decoding circuit, computer interface. The basic working principle of the bar code scanner / bar code scanner is: the light emitted by the light source is illuminated by the optical system to the bar code symbol, and is reflected back by the optical system imaging in the photoelectric converter, which is interpreted as a digital signal directly accepted by the computer.
Classification of a bar code scanner
Commercial bar code scanners are commonly used: CCD scanners, laser hand-held scanners and three kinds of full angle laser scanners.
1, CCD scanner is the use of photoelectric coupling (CCD) principle, the imaging of printing bar code, and then decode.
Its advantages are: no shaft, motor, long service life; the price is cheap.
When you select a CCD scanner, the most important is the two parameter:
Jingshen: because of the imaging principle of CCD is similar to the camera, if you want to increase the depth of field, corresponding to increase the lens, so as to make the CCD size is too large, inconvenient operation. Good CCD should not cling to the barcode reader, and moderate volume, comfortable operation.
Resolution: if you want to improve the resolution of CCD, you must increase the unit element of the imaging unit. Low CCD is generally 5 pixels, reading ean, UPC and other commercial code is enough, for some other code reading will be difficult. Class CCD to 1024pixel for more, some even reach 2048pixe1, can identify the most narrow unit element for 0.1mm's bar code.
2, laser hand-held scanner is the use of laser diode as the source of a single line scanner, it mainly has two kinds of rotating mirror and mirror type
Rotating mirror is the representative of the brand is SP400, it is the use of a high speed motor driven by a prism rotation, so that the single point of laser beam into a line.
The production cost of the mirror is lower than the rotating mirror, but the laser gun is not easy to improve the scanning speed, generally 33 times per second. Individual models, such as POTICON can reach 100 times per second, the brand is Symbol, PSC and POTICON.
Commercial enterprises in the selection of laser scanner, the most important is to pay attention to the scanning speed and resolution, and the depth of field is not a critical factor. When the depth of field is increased, the resolution will be greatly reduced. Hand-held laser scanner should be excellent high scanning speed, fixed depth range of high resolution.
3, the angle of scanner is through the optical system of the laser diode emits laser refraction or a plurality of scanning lines of the bar code scanner, the main purpose is reduce receivables bar code input data alignment bar code of labor, the choice should focus on scanning line of the mosaic distribution:
In one direction, there are multiple parallel lines and at one point, there are multiple scan lines.
In line with the above three points, the whole point of view of the scanner will be the preferred business applications.
Two, how to choose the right bar code scanner
★ CCD scanner is generally used for money tight, suitable for less demanding situations, such as the general supermarket.
★ The gun type laser scanner. The price is moderate, scanning speed, high accuracy, high requirement for.
★ This platform laser scanner for slightly higher prices, easy to use, f
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