| 摘要 |
PROBLEM TO BE SOLVED: To satisfactorily measure the toner print density of an electrophotographic device from high to low density. SOLUTION: A laser beam is emitted to the surface of an intermediate transfer body 14 from a slanting position, and the position of the reflected laser beam is detected. Because the laser beam reflected from the intermediate transfer body 14 and a laser beam reflected from toner transferred to the intermediate transfer body 14 differ in position in proportion to the thickness of the toner, the thickness of transferred toner is detected from the positional change and this is converted into the print density. Because the print density is not read from the intensity of the reflection, it is not effected by the characteristic of an optical sensor. |
