| 摘要 |
PROBLEM TO BE SOLVED: To identify each photosensitive sensor by setting the detection threshold to the output signal that is produced for each sensor and illuminating in turn some of plural sensors via a controller, in response to the signal having a 1st state. SOLUTION: In sensitivity or switching threshold is set at one of 255 values, for example, which are decided by a digital word D that is generated at a control logical part 301. A highest sensitivity is obtained, when the word D that secures the least current lref is set at 255. When a blank cluster is used, no marker M is generated, and some of plural photosensitive sensors are illuminated by the undesired light. The delay is applied to detect those illuminated sensors which are notified to a conversion microcomputer controller 900 within a display frame period. The sensors are illuminated by the undesired light, if the test is 'YES'. |
