| 摘要 |
A compensator for the horizontal angular error of a record player arm. A first lever is disposed in a horizontal plane beneath the player arm, a first, fixedly positioned bearing supporting an intermediate portion of the first lever so that such lever can rotate in a horizontal plane. The first lever has a bearing on a first end thereof journalling a vertically rotatable shaft upon which the player arm is mounted for limited vertical motion with respect to the arm but so as to rotate horizontally with the vertical shaft. A second lever in the form of a flat horizontal optical mask is affixed to the vertical shaft to rotate therewith, the optical mask having an arch-shaped slit therein which is convex in the direction away from the axis of the vertical shaft. A source of light is disposed close to the optical mask on one side thereof, and two spaced photo-receivers are disposed on the other side of the optical mask. A blind is disposed between the optical mask and two photo-receivers, the blind having a linear slit therein directed radially of the vertical shaft. Electric circuit means connects the two photo-receivers to an electric motor drivingly connected to the first lever so as to energize the motor to drive the first lever constantly to seek a position in which the illuminations of the two photo-receivers are equal. |
