| 摘要 |
<p>PURPOSE: To compensate the difference in width of bars on a bar code label by measuring the read time of one bar to set the time of a timing device. CONSTITUTION: A controller 46 has timers 0 and 1. The timer O is used to measure the duration of one bar element or that of a combinational element called trunk. Each bar element is read within 4ms. When calculation of the character end time is determined, the timer 1 is stopped, and the time elapsed of the timer 1 is subtracted from 23.5ms as its initial load time. The obtained time is divided by 4.096ms to determine how many bar elements pass and are detected by a sensor. The character read speed is recorded in the controller 46, and this measured speed is a reference time for detection of characters following the end character.</p> |
