PURPOSE: To extract proper bar code signals and to reduce the mixture factor of noises excepting code signals by referring to the regular continuity of the width of white and black bars with the scan signal scanning bar codes.
CONSTITUTION: The pulses corresponding to the width of white and black bars are delivered alternately from a scanner 11. A white/black and black/white width counter 13 adds those white and black bar pulses delivered alternately and delivers them. In other words, the counter 13 detects a change from the white to black bar with reference to the signal supplied from a white/black and black/white change detecting circuit 14. Then the pulse width of the white bar is added to the pulse width of the black bar before it is changed into the black bar to obtain the black/white width data. In the same way, the pulse width of the black bar before it is changed into the white bar is added to the pulse width of the white bar before it is changed into the black bar to obtain the white/ black width data. These width data are stored in a data shift register 20 and a buffer memory 16 respectively.
ISHII KAZUO
IRIONO MASATOSHI
NIPPON ELECTRIC ENG
| JPS53132944A | 1978-11-20 |