| 摘要 |
PURPOSE:To simplify an installation process and parts, and to prevent deformation of a mask in case of a high temperature, by installing a mask as floating between an encoder housing having a fitting part for aligning an installing position to the mask, and a holding plate fixed so as to be opposed to said hous- ing. CONSTITUTION:An encoder housing 4 provided with a hole for making a rotary shaft 2 pass through is fixed to a rotary device 1, in which a light emitting element 3 is placed. To the rotary shaft 2, a disk 6 where a lot of slits have been placed at equal intervals on the circumference corresponding to the light emitting element 3 is fixed. A housing 9 to which a flexible printed board 7 having a photdetector 7a has been installed so as to be opposed to the light emitting element 3 is fixed to the housing 4 through a holding plate 8. In front of the photodetector 7a, a mask 11 having a slit 10 is placed in a recessed part 12 as floating by separating it from the holding plate having a square hole 13 by DELTAl1. As for the mask, it is unnecessary to screw it, therefore, the installation process and parts are simplified, and also deformation in case of a high temperature is prevented. |
