Barcode detection device

Abstract

Abstract PURPOSE:To stably decode a bar code by transmitting an external command signal to a variable gain amplifier circuit when decoding fails and sequentially setting the gains of a variable gain circuit to a preset amplification ratio so as to decode it. CONSTITUTION:When decoding fails, a microprocessor 15 varies the external command signal and sets only an analog switch 172. In such case, the amplification ratio is multiplied by 44. Then a bar width signal is again fetched and decoded. When decoding fails, the external command signal is varied, and in this time only an analog switch 173 is set, and bar width data is fetched and decoded. In such case the amplification ratio is multiplied by 11. In such a way the amplification ratio falls into three steps; 22 times, 44 times and 11 times. Thus the bar code can be stably decoded even if the detection position of the bar code, reflectance, a printing density and an angle to scan change are changed.

Inventors

• 👤 Naotsugu Tokumura
• 👤 徳村　直継
• 👤 Seiichiro Tamai
• 👤 誠一郎 玉井
• 👤 Keiichi Kobayashi
• 👤 圭一 小林

Bibliographic Details