ARM BASE DRIVING CONTROL SYSTEM FOR LINEAR TRACKING PLAYER

摘要

PURPOSE:To avoid a sudden shift of an arm base and to improve both the S/N and the wow and flutter, by providing a detector to the driving system of the arm base to detect the acceleration when the arm base moves, and therefore controlling the acceleration of the arm base. CONSTITUTION:A straight line connecting the fulcrum of a tone arm 5 and the tip of a stylus forms a certain angle to the tangent line of a sound groove on a record in accordance with the shift of the stylus tip and during a reproduction of the record. This angle is detected by a displacement sensor 2, and the position control voltage corresponding to the angle is applied to an adder 13 from a differential amplifier 7 to be fed to a driving motor 1. Thus the motor 1 is driven to give a horizontal shift to an arm base 3 so as to set the above-mentioned angle at 0. In this case, the moving speed of the base 3 is detected by a magnetic signal plate 9, a Hall device 10 and a speed detecting 11 respectively. Then the acceleration control voltage supplied from a differentiating circuit 12 is delivered to the adder 13 to apply a feedback to the motor 1. Thus a sudden action is avoided to perform a control.