| 摘要 |
In a laser printer 11 including a light source 13, a photosensitive drum 15, an oscillating minor 17, a beam detector 18, and a control circuit 35, the light source shines a light beam towards the oscillating minor, which reflects the light beam towards the photosensitive drum. The beam detector detects light reflected from the oscillating minor. A reflected light beam hits the beam detector twice in each period of the oscillating minor. The time interval between detected beams is used to determine the maximum mechanical deflection angle of the oscillating minor. Two beam detectors may be used to detect light reflected from the oscillating minor and determine its maximum mechanical deflection angle. The oscillating mirror may be part of a Micro Electro Mechanical System (MEMS) device. |
