| 摘要 |
<p>PURPOSE:To improve its reading accuracy by scanning a recessed/projected bar code by a displacement sensor, finding out the area of the obtained recessed/ projected waveform and comparing the found area with a reference area expressed by thick lines and thin lines to decide the pattern of the bar code. CONSTITUTION:The reading waveform of the recessed/projected bar code 6 on a tire 5 is read out as a waveform H superposed to the base of the tire 5 because the tire 5 is rotated by a rotating device while being vibrated and the base is slowly changed without being kept at a fixed level, and then temporally stored in a RAM 4d. A CPU 4b divides the read-out waveform H in each unit (t) stored in a ROM 4c, finds out the maximum value Hmax and the minimum value Hmin in the unit time and calculates the center value Hm sets up the center value Hm as the threshold in each unit time (t). Values less than the threshold are discarded to obtain the waveform HS. The waveform HS is limited and respective areas of the obtained waveform Hr are found out and whether the value corresponds to the thick bar cord or the thin bar code is determined.</p> |
