The laser handheld scanner is a single-line scanner that USES the laser diode as the light source. The representative brand of the rotary mirror is the ACAN 8500, which USES a high-speed motor to turn a set of prisms, turning the single-point laser emitted by the diode into a line. The laser line scan the barcode itself, black absorbs most of the laser, white reflects most of the laser, at the same time reflect light through the optical lenses, in the "engine" reflection, focused on a photoelectric triode, observations in the time domain, scan the barcode photoelectric laser output low level three black belt, leucorrhea power transistor high level on time. After several times of amplification, the shaping is a rectangular wave, which corresponds to the scanned barcode. The resulting waveform is then transmitted to the decoder via the data line. "Codecs" actually is for a single chip microcomputer, rely mainly on interrupts, and a single chip microcomputer counter record waveform jump time, collected by the sequence to be the time when the next scan or flyback digital decoder, rely mainly on these counters count to decode the corresponding bar code, the percentage of time in the practical application, there are many different kinds of bar code, and shall meet with irregular folds such as blister packing, so the decoding part needs certain fault tolerance, but it does not produce error. Decoder MCU is generally divided into 8 bits and 32 bits, 8 bits advantage lies in the price, 32 bits lie in the speed. Laser bar code market mixed, also followed the CCD scanner, prices have been low, cheap copy rampant, but the domestic strength of the manufacturers also has a few, consumers need to carefully consider what brand to use, choose the most suitable.
The manufacturing cost of the chatter mirror is lower than that of the rotating mirror, but the laser gun of this principle is not easy to improve the scanning speed, generally 33 times per second. Some models, such as the OPTICON, can reach 100 times per second. The representative brands are Symbol, PSC and OPTICON, and the most representative one is Symbol 2208
When choosing a laser scanner, the most important thing for commercial enterprises is to pay attention to scanning speed and resolution, and the depth of field is not the key factor. As the depth of field increases, the resolution decreases. A good handheld laser scanner should have high scan speed and high resolution over a fixed depth of field.