| 摘要 |
<p>PURPOSE:To obtain a dynamic drive circuit for a photosensor with a simplified wire harness while employing a single comparator by using an analog switch to switch a load resistor of a photosensor output section dynamically. CONSTITUTION:An analog switch 7 switches an analog input corresponding to SCAN signals A, B, C changing from binary 0 to 7. That is, when the SCAN signal is 0, a variable resistor 6a is connected to a photosensor output section and when the SCAN signal is logical 1, a variable resistor 6b is connected to the photosensor output section, and the load resistance of the photosensor output section is switched to respective variable resistor in response to the SCAN signal. As a result, the load resistance in response to the output level different from each photosensor is set. The output of the comparator 3 is sampled synchronously with the dynamic drive timing by FFs5a, 5b-5g.</p> |
