| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method which is capable of optically measuring a width of a doctor gap regardless of a shape of a developing device. <P>SOLUTION: A retroreflective member 26 is provided on an inner wall of an enclosure 21, and light is irradiated toward the retroreflective member 26 from the outside of a developing device 20 by light emitting means 51, and light reflected by the retroreflective member 26 is detected by optical detection means 52 to measure a doctor gap G. Preferably, a half mirror 53 is provided in an optical path between the light emitting means 51 and the doctor gap G, and light is irradiated to the retroreflective member 26 from the light emitting means 51 through the half mirror 53, and light reflected by the retroreflective member 26 is separated by the half mirror 53 and is detected by the optical detection means 52. <P>COPYRIGHT: (C)2012,JPO&INPIT |
