Sound track selector system for phonograph record players Patent #: 3937903
ApplicationNo. 682079 filed on 04/30/1976
US Classes:369/33.01, Specified electrical control signal processing250/214B, Ambient light desensitizing means250/570, Tape, drum, or disc types327/72, Input signal compared to reference derived therefrom369/206By center hold feeding of disc (e.g., spindle drop)
ExaminersPrimary: Konick, Bernard
Assistant: Faber, Alan
Attorney, Agent or Firm
International ClassG11B 019/14
AbstractA programmable phonograph record changer which provides automatic sound track selection for each of a plurality of records played sequentially by the record changer. The record changer includes an electro-optic scanner mounted on the pickup arm for sensing the land areas located between the various sound tracks of a disc-type record. An auxiliary tone arm lift and sweep mechanism is controlled by a digital logic system connected to the electro-optic scanner to drive the tone arm across various bands which the user does not want to be reproduced. The logic system includes a programmable memory which stores the preselected sound tracks of a sequence of records which the user intends to be reproduced. A land sensing circuit includes a means for developing a threshold signal which varies with the record surface reflectivity characteristics.