| 摘要 |
<p>PURPOSE:To reduce the reading error of bar codes by measuring and storing successively the dimension of a pair of bright and dark parts adjacent to the bar code and discriminating the information based on the data measured successively. CONSTITUTION:The bar code digital signal BD sent from a signal input terminal 1 of a bar code reader is supplied to a start end signal generating circuit 2 as well as to a control signal generating circuit 4. The circuit 2 produces start signals S1 and S2 as well as an end signal Se synchronously with the pulse generated from a clock pulse oscillator 5. These signals S1 and Se are applied to the circuit 4 via a D-FF3 and a gate 6, and at the same time the signal S2 is applied to the circuit 4. The circuit 4 produces an initial reset signal SR, a latch timing signal SL, a memory timing signal SM, etc. Then a bar code counter 7 measures successively the dimension of a pair of bright and dark parts of adjacent bar codes. The data of this measurement is stored in an RAM11, and the bar code information is discriminated based on the data stored in the RAM11.</p> |
