Focused line identifier for a bar code reader

摘要: A focused line identifier is useful in a bar code reader employing Scheimpflug optics for focusing an illuminated from the on two dimensional array of photodetectors. One or small group lines somewhere sharpest focus within working range scanner. The best located with analog signal before digitizing by generating having amplitude representative high frequency component photodetector array. maximum may be found passing through pass filter detecting largest amplitude. is, effect, one field scan and used to open gate next digitizer. also hop adjacent focuesd feeding slightly unfocused Further, zone photodetectors which has greatest illumination selected disregarding spurious signals other objects that happen lie view reader.