| 摘要 |
PROBLEM TO BE SOLVED: To obtain a detector small in size, low in cost and capable of accurately detecting the positional deviation or position of a registration by receiving light beams respectively reflected on a movable reflection surface and a fixed reflection surface and detecting the write starting position of the registration from the poistional deviation of the respective reflected light beams. SOLUTION: Infrared light emitted from an infrared light emitting element 52 is transmitted through a transfer belt 1, reflected on a reflector 7 being the 2nd fixed reflection surface, and formed into an image at a point (a) on a PSD 62. When the belt 1 is driven and the transferred toner reaches the position of a point 12, the infrared light is reflected by toner being the 1st reflection surface, and formed into the image at a point (b) on the PSD 62. At such a time, since the infrared light reaching the 2nd reflection surface is intercepted, the image forming point on the PSD 62 is changed from (a) to (b). When the transferred toner is not found, the infrared light reflected on the 2nd reflection surface again is formed into the image at the point (a) on the PSD 62. Thus, a light receiving position on the PSD 62 is detected and the position of the registration is accurately detected. |
