GB1485061A - Liquid crystal protection circuit - Google Patents

Liquid crystal protection circuit

Info

Publication number
GB1485061A
GB1485061A GB581/75A GB58175A GB1485061A GB 1485061 A GB1485061 A GB 1485061A GB 581/75 A GB581/75 A GB 581/75A GB 58175 A GB58175 A GB 58175A GB 1485061 A GB1485061 A GB 1485061A
Authority
GB
United Kingdom
Prior art keywords
oscillator
driving circuit
transistor
liquid crystal
backplate
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
GB581/75A
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.)
RCA Corp
Original Assignee
RCA Corp
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 RCA Corp filed Critical RCA Corp
Publication of GB1485061A publication Critical patent/GB1485061A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/50—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to the appearance of abnormal wave forms, e.g. ac in dc installations
    • 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
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
    • G—PHYSICS
    • G04—HOROLOGY
    • G04G—ELECTRONIC TIME-PIECES
    • G04G9/00—Visual time or date indication means
    • G04G9/0023—Visual time or date indication means by light valves in general
    • G04G9/0029—Details
    • G04G9/0047—Details electrical, e.g. selection or application of the operating voltage

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Oscillators With Electromechanical Resonators (AREA)
  • Electric Clocks (AREA)
  • Liquid Crystal (AREA)

Abstract

1485061 Controlling light RCA CORPORATION 581/75 7 Jan 1975 [27 March 1974] Heading G2 [Also in Divisions H2 and H3] The power supply for the driving circuit 12 of a liquid crystal display 14 is automatically cut off if the oscillator 10 controlling the driving circuit fails, thereby avoiding prolonged application of a steady voltage to the crystal. The power supply is derived from a source VEE via a switching transistor 16, controlled by the oscillator, and a smoothing capacitor C 2 . So long as the oscillator is functioning, transistor 16 is repeatedly switched on to maintain C2 fully charged, but if oscillations cease transistor 16 remains permanently off. The driving circuit may comprise COS/MOS transistors switched under the control of the oscillator to provide a squarewave which is applied to both the backplate and segments of the display 14, the waveform applied to those segments that are to be displayed being 180 degrees out of phase with the waveform applied to the backplate.
GB581/75A 1974-03-27 1975-01-07 Liquid crystal protection circuit Expired GB1485061A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US455372A US3873888A (en) 1974-03-27 1974-03-27 Liquid crystal protection circuit

Publications (1)

Publication Number Publication Date
GB1485061A true GB1485061A (en) 1977-09-08

Family

ID=23808523

Family Applications (1)

Application Number Title Priority Date Filing Date
GB581/75A Expired GB1485061A (en) 1974-03-27 1975-01-07 Liquid crystal protection circuit

Country Status (10)

Country Link
US (1) US3873888A (en)
JP (1) JPS50129241A (en)
CA (1) CA1033480A (en)
CH (2) CH74475A4 (en)
DE (1) DE2501114C3 (en)
FR (1) FR2266207B1 (en)
GB (1) GB1485061A (en)
HK (1) HK55180A (en)
MY (1) MY8100199A (en)
SU (1) SU563931A3 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51135499A (en) * 1975-05-20 1976-11-24 Seiko Epson Corp Liquid crystal display unit
DE2939553A1 (en) * 1979-09-28 1981-04-02 Eurosil GmbH, 8000 München CIRCUIT ARRANGEMENT FOR CONTROLLING A MULTI-DIGIT LIQUID CRYSTAL DISPLAY
JPS5877391U (en) * 1981-11-20 1983-05-25 トキコ株式会社 liquid crystal display circuit
JPH0693166B2 (en) * 1984-09-05 1994-11-16 株式会社日立製作所 Liquid crystal element
DE3807020A1 (en) * 1988-03-04 1989-09-14 Eurosil Electronic Gmbh Liquid crystal display having clock-controlled disconnection

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB505490A (en) * 1937-10-11 1939-05-11 Eric Lawrence Casling White Improvements in or relating to cathode ray tube television and like apparatus
US3588608A (en) * 1969-02-24 1971-06-28 Sun Electric Corp Circuit protection apparatus for disabling high voltage to a cathode-ray tube
DE2150621A1 (en) * 1971-10-11 1973-04-19 Rca Corp CONTROL CIRCUIT, IN PARTICULAR FOR A LIQUID CRYSTAL CELL
GB1425828A (en) * 1972-04-24 1976-02-18 Rca Corp Electron beam tube protection circuit

Also Published As

Publication number Publication date
SU563931A3 (en) 1977-06-30
CA1033480A (en) 1978-06-20
FR2266207A1 (en) 1975-10-24
CH74475A4 (en) 1977-01-31
DE2501114A1 (en) 1975-10-09
FR2266207B1 (en) 1978-04-21
DE2501114B2 (en) 1981-07-02
MY8100199A (en) 1981-12-31
US3873888A (en) 1975-03-25
CH610713B5 (en) 1979-05-15
JPS50129241A (en) 1975-10-13
HK55180A (en) 1980-10-10
DE2501114C3 (en) 1982-02-25

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PCNP Patent ceased through non-payment of renewal fee