Bar code reader

Abstract

Abstract PURPOSE:To ignore the head width value within a storage means and to restart decoding with the next width value in case an error arises before detection of bars, by reading and storing the width value corresponding to the region of each bar and generating characters. CONSTITUTION:A bar code is irradiated by a hard scanner 1, and the light reflection factor is converted into electric signals. These electric signals are converted into digital signals by an A/D converter 2 and supplied to a pulse detecting circuit 3. The circuit 3 detects the rise and fall of a pulse to apply them to an AND gate 4 as a trigger, and the output of the gate 4 is applied to a CPU5 as an interruption signal. Memories M and D, a time counter Tc and an SR type FF6 are connected to the CPU5. Then the CPU5 obtains the width value corresponding to the region of each read bar. The read width value is stored to generate characters. When an error arises before detection of bars, the head width value of the memory M is ignored. Then the decoding is restarted with the next width value.

Inventors

• 👤 Shigeru Yamada
• 👤 繁 山田

Bibliographic Details