The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 10, 1981
Filed:
Jan. 17, 1979
Robert J Hudson, London, GB;
Molins Limited, London, GB;
Abstract
A bistable circuit comprises a light-emitting diode connected in series with a phototransistor and so disposed as to illuminate the latter. When current is flowing--i.e. when the phototransistor conducts--light from the LED keeps the phototransistor conductive, and the circuit can be switched to the non-conductive (OFF) state by interrupting the light path between the LED and the phototransistor. When the circuit is OFF it can be switched to the ON state by external light. A data-storage device embodying such bistable circuits is also disclosed; a rotatable disc carries a plurality of such circuits at regular spacings adjacent its periphery, and several setting devices at different positions are each operable to illuminate one of the circuits passing the setting device to switch that circuit to the ON state. After passing the several setting devices, each circuit is carried past a sensing device which detects whether the circuit is ON (by detecting whether light is being emitted from the circuit) and thereafter past a stationary shutter so placed as to interrupt the light path of the circuit and hence reset any circuit which is ON to the OFF state.