GB1383540A - Keyboards - Google Patents

Keyboards

Info

Publication number
GB1383540A
GB1383540A GB4105772A GB4105772A GB1383540A GB 1383540 A GB1383540 A GB 1383540A GB 4105772 A GB4105772 A GB 4105772A GB 4105772 A GB4105772 A GB 4105772A GB 1383540 A GB1383540 A GB 1383540A
Authority
GB
United Kingdom
Prior art keywords
key
liquid crystal
crystal device
photosensitive devices
conductors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB4105772A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BAE Systems Electronics Ltd
Original Assignee
Marconi Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Marconi Co Ltd filed Critical Marconi Co Ltd
Priority to GB4105772A priority Critical patent/GB1383540A/en
Publication of GB1383540A publication Critical patent/GB1383540A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/965—Switches controlled by moving an element forming part of the switch
    • H03K17/968—Switches controlled by moving an element forming part of the switch using opto-electronic devices
    • H03K17/969—Switches controlled by moving an element forming part of the switch using opto-electronic devices having a plurality of control members, e.g. keyboard
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/1313—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells specially adapted for a particular application

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal (AREA)

Abstract

1383540 Keyboards MARCONI CO Ltd 18 July 1973 [5 Sept 1972] 41057/72 Addition to 1299979 Heading G4H In a keyboard, each key controls the intensity of light incident upon an associated set of photosensitive devices by applying a voltage to a liquid crystal device arranged between the set of photosensitive devices and a source of light. A plurality of conductors each contain a photosensitive device at each of a number of key locations but the conductors are continued over the photosensitive devices (thus covering them) except for a characteristic combination at each key location to give a coded output. The liquid crystal device at each key location may be a twisted nematic liquid crystal with associated crossed polarizers, a voltage being capaeitively coupled to the crystal device from a plate on the key.
GB4105772A 1972-09-05 1972-09-05 Keyboards Expired GB1383540A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4105772A GB1383540A (en) 1972-09-05 1972-09-05 Keyboards

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4105772A GB1383540A (en) 1972-09-05 1972-09-05 Keyboards

Publications (1)

Publication Number Publication Date
GB1383540A true GB1383540A (en) 1974-02-12

Family

ID=10417919

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4105772A Expired GB1383540A (en) 1972-09-05 1972-09-05 Keyboards

Country Status (1)

Country Link
GB (1) GB1383540A (en)

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee