| 摘要 |
PURPOSE:To contrive the thinning of a device by housing a scale to detect the position of a head arm, a light emitting element and a light receiving element in the range of the fitting height of the head arm in a sealing case. CONSTITUTION:A head arm 6 is freely-rockably attached to the outer periphery of a rocking central shaft 7 fixed on a bottom part 1a of a hermetically sealing case 1. Further, by using the outer peripheral space of the rocking central shaft 7, a scale 20 is attached to the bottom part of a head arm 6, a light emitting element 22 and a light receiving element 23 are arranged in the upper and lower spaces of the scale 20, and the scale 20, the light emitting element 22 and the light receiving element 23 are housed in the range of the fitting height of the head arm 6 in the sealing case 1. Thus, the device can be made thinner. |
