This invention relates to apparatus useful in applications such as a video disc player and more particularly to the stylus assembly for recovering the recorded signal from a disc record.
Information is recorded on video discs in generally circular tracks or a continuous spiral track having an extremely small pitch, e.g., 10,000 tracks per inch. Those systems which employ a track following stylus for signal recovery require a pickup stylus with concomitantly small dimensions. In order that the stylus faithfully track the information track, the dynamics of the stylus assembly normal to the disc must be designed to relatively critical tolerances. Typically the stylus is rigidly mounted to the free end of a stylus arm of low mass. The opposite end of the stylus arm is compliantly mounted to a carriage assembly and stylus-disc pressure is provided by a leaf spring arranged in an arc between the stylus and the carriage assembly.
The capacitive disc player systems utilize a stylus having an electrode adherent to one of its faces which is generally normal to the disc. Electrical contact is made to this electrode via the leaf spring. The leaf spring has a hole in one end which is designed to slide over the stylus. The leaf spring is then soldered, welded, or glued with conductive cement to the stylus electrode. Alternatively the hole in the leaf spring may be arranged with tines so that it is self retentive to the stylus. In addition, the leaf spring is staked to the stylus arm to preclude imposing twisting forces, etc. on the stylus body.
It has been found, however, that compliantly securing the stylus to the stylus arm enhances tracking of the disc. In order to achieve this result, it is required that the leaf spring be indirectly connected to the stylus electrode. This in turn imposes contraints on the sequence of assembly of the recovery apparatus during manufacturing operations. The present invention affords both a mounting means for limited decoupling of the stylus from the stylus arm and for facilitating assembly of the recovery apparatus.