| 摘要 |
<p>PURPOSE:To read out a normal bar code having low against a ground and a specific bar code having high lightness by inverting the output of an image sensor by an inversion means when deciding the impossible of bar code reading. CONSTITUTION:When the leading end of a wand 11 come into contact with a label 2, each photodiode 17 outputs a required signal in accordance with the lightness of a bar code 3. The output of each photodiode 17 is transferred from a shift gate 18 to a shift register 19 by a parallel loading signal. The output transferred from each photodiode 17 to the shift register 19 by every input of shift clocks phi1, phi2 is inputted to a waveform shaping circuit 16. The data of a binary-coded bar code 3 are read by an input port I 25 and written in a RAM 22. When all the bits of a CCD linear sensor 15, i.e. the data of all photodiodes, are inputted, a subroutine for reading the CCD linear sensor 15 is completed.</p> |
