Turnable, contactless variable resistor

{
  "publication_number": "US3859617A",
  "country": "US",
  "kind": "A",
  "title": "Turnable, contactless variable resistor",
  "abstract": "A turnable, contactless variable resistor is provided consisting of a light source and a photoconductive cell, capable of operation without producing noise and wear as distinguished from conventional turnable variable resistors having mechanical contact.",
  "claims": [
    "1. A turntable, contactless variable resistor comprising: an opaque disk having a shaft that is rotatable about a given axis; an opaque upper supporting plate having an opening therethrough for transmitting light and a bearing for the free turning of said disk about the shaft axis; a light source fixed to the upper supporting plate and completely on one side thereof; an opaque lower supporting plate having an opening therethrough for transmitting light from the light source disposed coaxially with the hole on said upper supporting plate; a photoconductive cell fixed to the opening of said lower supporting plate and completely one one side thereof; and said disk having an opening disposed between said upper and lower supporting plates at a radial position corresponding to the radial position of the openings in said supporting plates said supporting plates being joined as one body with said one side on the outside of said body, and the conducting resistance of said photoconductive cell varying by means of a changing amount of light passing through the openings by turning said rotatable shaft.",
    "2. A turnable, contactless variable resistor as defined in claim 1 wherein, a photoconductive cell is attached on the opening of said upper supporting plate and a light source on the opening of said lower supporting plate.",
    "3. A turnable, contactless variable resistor as defined in claim 1 wherein, the opening of the disk is a large comma like shape, whose radial distance varies with the angular displacement of the disk about the shaft axis.",
    "4. A turntable, contactless variable resistor as defined in claim 1 wherein: the upper supporting plate has a second opening for transmitting light; the lower supporting plate has a second opening located coaxially with said corresponding opening on said upper supporting plate; and a second light source and a second photoconductive cell are attached in positions corresponding to those associated with said first light source and photoconductive cell; whereby the resistances of the first and second photoconductive cells may be varied at the same time in response to rotation of the shaft.",
    "5. A turntable, contactless variable resistor as defined in claim 4 wherein, the opening of the disk is a large comma-like shape, whose width measured radially varies with angular displacement of the disk about the shaft axis."
  ],
  "cpc": [
    "H10F 55/208"
  ],
  "assignees": [
    "MATSUSHITA ELECTRIC INDUSTRIAL CO LTD"
  ],
  "filing_date": "1973-09-20",
  "publication_date": "1975-01-07",
  "grant_date": "1975-01-07",
  "priority_date": "1972-09-26",
  "application_number": "US-39915073-A",
  "family_id": "14593005",
  "citations": [
    "US3102227A",
    "US3171034A",
    "US3358150A"
  ]
}