Optoelectronic switch

Abstract

A light actuated switch apparatus is described in which no movable switch contacts are employed. The switch uses a light source and shutter to activate an array of light sensitive devices to generate a binary code that provides the switching function. One embodiment of the switch apparatus is employed inside a control knob providing a binary code generated by shutter action of a light source on an array of photo-transistors. Another embodiment .[.employes.]. .Iadd.employs .Iaddend.the above control knob including switch apparatus as well as a second knob and printed board to form a dual switch apparatus. As no switch contacts are employed there is considerable reduction in electrical components. Additionally, this also greatly reduces the space required for mounting the switch, is readily serviceable or replaceable as no parts are located within an instrument, and is less expensive as no contacts eliminate any wear and potential problems associated with movable through stationary contacts.

The invention is claimed in accordance with the following: .[.1. An optoelectronic switch, comprising: 
     
        coupled device..]. 11. An optoelectronic switch, comprising: a first movable housing member;   a second movable housing member operatively disposed within said first movable housing member;   stationary radiation source means disposed within said second movable housing member, said stationary radiation source means for providing electromagnetic radiation;   movable masking means operatively disposed in said second movable housing member, said movable masking means for selectively masking said electromagnetic radiation to provide a coded electromagnetic radiation;   stationary radiation .[.sensative.]. .Iadd.sensitive .Iaddend.means disposed inside said second movable housing member, said stationary radiation sensitive means for collecting said coded electromagnetic radiation to provide an electrical signal proportional to said coded electromagnetic radiation; and   means operatively disposed inside said first housing member, said means for selectively receiving said .[.electricl.]. .Iadd.electrical   
     
     
        .Iaddend.signal to provide a selectable electrical signal. 12. The switch according to claim 11 wherein said first and said second movable housing 
     
     
        members move independently from one another. 13. The switch according to claim 11 wherein said means operatively disposed inside said first movable housing member defines a circuit board means including selectable connection members. .Iadd. 14. An optoelectronic switch, comprising a rotatable housing,   a masking member mounted within and coupled to said housing for rotation therewith, said member including a plurality of light transmissive windows,   stationary light sensitive means disposed within said housing facing one side of said masking member for detecting incident light and generating an electrical signal proportional thereto, and   stationary light source means disposed within said housing facing the opposite side of said masking member for directing light toward said light sensitive means,   1ight from said source means passing through certain of said windows at different rotational positions of said housing to illuminate said light sensitive means and thereby produce electrical output signals at such positions. .Iaddend..Iadd. 15. The switch of claim 14, further including detent means within said housing for indexing said masking member at different rotational positions. .Iaddend..Iadd. 16. The switch of claim 14, wherein said masking member comprises a disc mounted for axial rotation, said windows being disposed in a selected pattern in the disc to provide different electrical output signals at different rotational positions. .Iaddend..Iadd. 17. The switch of claim 14, wherein said light sensitive means comprises a plurality of photodetectors and said light source means comprises a like plurality of light emitting devices, each directing light toward a different one of said photodetectors, different individual ones and groups of said photodetectors being illuminated by light passing through said windows at different rotational positions of the housing to generate different, coded electrical signals at such positions. .Iaddend.