| 摘要 |
PURPOSE:To improve reproduction characteristics by correcting the eccentricity of the center of a record from the center of rotation of a turntable due to a gap between the center hole of the record and the spindle of the turntable, etc. CONSTITUTION:The record 1 is mounted on the turntable 3 by fitting its center hole 1a around a fitting spindle part 2. An arm 5 has a trace stylus for tracking the groove of the record at its tip and also has a shutter blade 8 interposed between a light emitting element 6a such as a lamp and a photodetector 7a for photodetecting light from the light emitting element 6a at the other end. The photodetector 7a outputs a necessary electric signal V which varies in level in response to the quantity of photodetected light due to the angular displacement of the arm 5, and this output is supplied to a control circuit 9. Further, the photosensor means consisting of a light emitting element 6b and a photodetector 7b is provided to detect information on the turning position of the turntable 3. |
