1.CCD scanner uses the principle of photoelectric coupling (CCD) to image barcode printing patterns, and then decode them. Its advantages are: no shaft, motor, long service life; low price.
When choosing a CCD scanner, the most important two parameters are: depth of field: because the imaging principle of CCD is similar to that of a camera, if the depth of field is to be increased, the lens should be enlarged accordingly, so that the volume of the CCD is too large and the operation is inconvenient. Excellent CCD should be able to read without sticking to barcode, and the volume is moderate and the operation is comfortable.
Resolution: If the resolution of CCD is to be improved, the unit elements of photosensitive elements at the imaging site must be added. Low-cost CCD is usually 5 pixels. It is enough to read EAN, UPC and other commercial codes. It will be more difficult to read other codes. Mid-range CCDs are mostly 1024 pixels, some even reach 2048 pixe1, which can distinguish the barcode with the narrowest unit element of 0.1 mm.
2.Laser hand-held scanner is a single-line scanner using laser diode as light source. It mainly has two types: rotating mirror type and chattering mirror type. Rotating mirror type uses high-speed motor to drive a prism group to rotate, so that the single-point laser emitted by the diode becomes a line. The manufacturing cost of the fibrillator type is lower than that of the rotating mirror type, but the laser gun based on this principle is not easy to improve the scanning speed, usually 33 times per second. When choosing a laser scanner, the most important thing is to pay attention to the scanning speed and resolution, and the depth of field is not the key factor. Because when the depth of field increases, the resolution will be greatly reduced. A good hand-held laser scanner should have high scanning speed and high resolution in a fixed depth of field.
3.All-angle scanner is a bar code scanner which makes laser diode refract or scan lines through optical system. Its main purpose is to reduce the work of aligning bar code when the cashier enters bar code data. When choosing the scanner, attention should be paid to the spot distribution of the scanning line.
The omni-angle scanner with multiple parallel lines in one direction, multiple scanning lines passing through a certain point, and the probability of interpretation of each point in a certain space range tends to be consistent with the above three points must be the preferred application for businessmen.