Video disc player having stylus protecting apparatus
AssigneeRCA Corporation
InventorsCharles B. Carroll, Alfred L. Baker
Life of this patent
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Abstract
The video disc player includes a selectively-actuated stylus arm lifter. When the player is in the PLAY mode, a forward bias is applied to the lifter electromagnet to cause it to lower the stylus on the record. When the player is disposed in the record LOAD/UNLOAD mode, the lifter is reverse biased to prevent the stylus from being lowered and coming in contact with moving parts during the record load/unload operations.
Claims5
In a player for recovering prerecorded information from a turntable-supported disc record by means of a record-engaging pickup stylus disposed at one end of a stylus arm during playback;
- said player including means for selectively lowering said stylus on said record for playback;
- said selectively lowering means having a stylus arm support, means for yieldably biasing said stylus arm support in a raised position to dispose said stylus away from said turntable, and a selectively-energized means for overcoming said bias to lower said stylus in response to a signal of first polarity;
- an apparatus comprising:
- means for applying a reverse polarity signal to said selectively-energized means, when the lowering of said stylus is not desired, to generate a force on said stylus arm support in a direction away from said turntable in addition to the upward force exerted on said stylus arm support by said yieldable biasing means.
In a player for recovering prerecorded information from a turntable-supported disc record by means of a record-engaging pickup stylus disposed at one end of a stylus arm during playback;
- said player including means for selectively lowering said stylus on said record for playback;
- said selectively lowering means having a stylus arm support, means for yieldably biasing said stylus arm support in a raised position to dispose said stylus away from said turntable, and a selectively-energized electromagnetic means for overcoming said bias to lower said stylus;
- said electromagnetic means comprising a winding having a pair of terminals;
- one of said terminals being connected to a given potential source;
- the other of said terminals being connected through a play switch to a ground potential sink;
- operation of said play switch causing said given potential source to drive a current through said winding in a first direction into said ground potential sink to effect said stylus lowering;
- apparatus comprising:
- (A) a higher potential source;
- (B) a record load/unload switch;
- (C) means for connecting said higher potential source to said other terminal of said winding via said load/unload switch;
- and
- (D) means for alternatingly actuating said play switch and said load/unload switch;
- operation of said alternatingly actuating means to open said play switch and to close said load/unload switch serving to disconnect said ground potential sink from said other terminal of said winding to block said current from passing through said winding in said first direction, and serving to cause said higher potential source to drive a current to flow through said winding in a reverse direction into said given potential sorce to prevent any tendency of said stylus to come down.
Dependencies are inferred from the claim text.