| 摘要 |
PURPOSE:To shift a tone arm at a high speed and to ensure the assured and stable follow-up of the arm in a play mode, by increasing the minimum unit of the count change degree of a counting means when the arm is shifted at a high speed and changing the minimum unit to a small level to drive a step motor in a play mode. CONSTITUTION:A system control circuit 18 supplies different count change degree control signals to a counter circuit 17 between a high-speed shift mode and a play mode of a tone arm 1. A comparator 14 compares the count number at the arm position given from the circuit 17 with the count number at a lead-in position given from a target value storing circuit 13. An indication signal is delivered to the circuit 17 from the circuit 18 to drive a motor 16 and to set the error value at zero. The minimum unit of the count change degree is increased when the arm 1 is shifting at a high speed, and therefore the arm 1 reaches quickly its target position. This minimum unit is switched to a small level in a play mode, and therefore the arm 1 can have stable follow-up with high S/N. |
