Kako delujejo laserski ročni skenerji črtne kode

Laserski ročni optični bralnik je eno{0}}vrstični skener, ki uporablja lasersko diodo kot vir svetlobe. V glavnem ima dve vrsti: tip vrtljivega zrcala in tip zrcala.

The representative brand of the rotating mirror type is ACAN 8500, which uses a high-speed motor to drive a prism group to rotate, so that the single-point laser emitted by the diode becomes a line. This laser line scans the bar code itself. The black bar code absorbs most of the laser light, and the white light reflects most of the laser light. At the same time, the reflected light passes through the optical lens in the "engine" and is reflected and focused on a phototransistor. Observe and scan in the time domain. Go to the black band of the barcode and output the low level of the photo-laser. When the white band is on, the photo-transistor is high. After several magnifications, the shape is a rectangular wave, which corresponds to the scanned barcode. The resulting waveform is then passed to the "decoder" section via the data line. The "decoder" is actually a single-chip microcomputer, which mainly depends on the interrupt and the single-chip computer counter to record the waveform jump time. The acquired sequence is digitally decoded during the next scan or retrace, and mainly depends on the time ratio of these counters to decode the corresponding In practical applications, there are many types of barcodes, and they need to encounter irregularities such as blister packaging folds, so the decoding part needs a certain degree of fault tolerance, but it cannot generate error codes. At present, the decoder microcontroller is generally divided into 8-bit and 32-bit. The advantage of 8-bit lies in the price and the speed of 32-bit. The laser bar code market is a mixed bag and has followed in the footsteps of ccd scanners. The price has repeatedly fallen and the cottage is rampant. However, there are several domestic manufacturers with strong capabilities. Consumers need to carefully consider what brand to use and choose the most suitable one.

Stroški izdelave vrste tremornega ogledala so nižji od stroškov rotacijskega zrcala, vendar laserska pištola s tem principom ni lahko povečati hitrosti skeniranja, ki je na splošno 33-krat na sekundo. Posamezni modeli, kot je OPTICON, lahko dosežejo 100-krat na sekundo. Reprezentativne znamke so Symbol, PSC in OPTICON. Najbolj reprezentativen je SYMBOL 2208.

Pri izbiri laserskega optičnega bralnika za komercialna podjetja je najpomembnejše biti pozoren na hitrost in ločljivost skeniranja, globinska ostrina pa ni ključni dejavnik. Ker se pri povečanju globinske ostrine ločljivost močno zmanjša. Odličen ročni laserski skener mora imeti visoko hitrost skeniranja in visoko ločljivost znotraj fiksne globine polja.