GB1286828A - Creation of Inventions and Patents with Artificial Intelligence

GB1286828A – Turn-off method and circuit for liquid crystal display element
– Google Patents

GB1286828A – Turn-off method and circuit for liquid crystal display element
– Google Patents
Turn-off method and circuit for liquid crystal display element

Info

Publication number
GB1286828A

GB1286828A
GB49178/69A
GB4917869A
GB1286828A
GB 1286828 A
GB1286828 A
GB 1286828A
GB 49178/69 A
GB49178/69 A
GB 49178/69A
GB 4917869 A
GB4917869 A
GB 4917869A
GB 1286828 A
GB1286828 A
GB 1286828A
Authority
GB
United Kingdom
Prior art keywords
crystal
turn
row
voltage
lead
Prior art date
1969-07-10
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
GB49178/69A
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.)
1969-07-10
Filing date
1969-10-07
Publication date
1972-08-23

1969-10-07
Application filed by RCA Corp
filed
Critical
RCA Corp

1972-08-23
Publication of GB1286828A
publication
Critical
patent/GB1286828A/en

Status
Expired
legal-status
Critical
Current

Links

Espacenet

Global Dossier

Discuss

Classifications

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

Abstract

1286828 Modulating light RCA CORPORATION 7 Oct 1969 [10 July 1969] 49178/69 Heading H4F The dynamic scattering state produced in a liquid crystal solely of the nematic type by the application of an electric field may be erased rapidly compared to the natural relaxation of the crystal following cessation of the electric field by applying an alternating voltage in the range 2-20 kHz, and preferably 7-8 kHz, to the crystal. It is believed that in this frequency range, the dipoles in the crystal are still able to align themselves with the electric field, whereas the mechanisms producing turbulence, i.e. injection of ions into the crystal have time constants which are too large. Fig. 1 (not shown) illustrates the effect of a 40 v, 10 millisecond, 7 kHz pulse immediately following a 50 v., 10 millisecond D.C. “turn-on” pulse, the turn-off time being reduced from 60 to 5 milliseconds. The alternating voltage may be left on at all times except when it is desired to produc the scattering state, and the contrast ratio may be improved by up to a factor of 2. Fig. 3 shows a suitable circuit for one cell of an array of liquid crystal cells using transistors which are “on” only when the gate voltage is one or more volts positive relative to the source voltage, and which are all “off” in the state shown. On switching row line R bn to +42 v., T1 is turned on but T3 remains off. If column lead Cn is simultaneously raised to + 41 v., T3 is turned on and a low frequency source 22 applies a field to the crystal 20 to produce the scattering effect. If row line R bn is now returned to – 40 v. and subsequently column Cn is also returned to – 40 v., the charge stored in the capacitance of the gate electrode of transistor T3 keeps that transistor “on”. To turn the crystal off, the voltage on row lead R an is switched from – 40 v. to + 42 v. for about 10 milliseconds, thus turning transistors T2 and T4 on, consequently discharging the gate of T3 and removing the low frequency source 22 while admitting high frequency excitation from a source 22 to the crystal. A matrix of such elements is illustrated in Fig. 4 (not shown), wherein a row lead and a column lead must be simultaneously energized to switch a particular crystal on and the erase operation occurs a row at a time. Instead of an array of cells, a single crystal may be used with a matrix of individual electrodes.

GB49178/69A
1969-07-10
1969-10-07
Turn-off method and circuit for liquid crystal display element

Expired

GB1286828A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

US84073169A

1969-07-10
1969-07-10

Publications (1)

Publication Number
Publication Date

GB1286828A
true

GB1286828A
(en)

1972-08-23

Family
ID=25283070
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB49178/69A
Expired

GB1286828A
(en)

1969-07-10
1969-10-07
Turn-off method and circuit for liquid crystal display element

Country Status (3)

Country
Link

US
(1)

US3575492A
(en)

CA
(1)

CA937291A
(en)

GB
(1)

GB1286828A
(en)

Families Citing this family (30)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US3896318A
(en)

1969-12-25
1975-07-22
Suwa Seikosha Kk
Driving device for liquid crystal cell

FR2082477A5
(en)

1970-03-17
1971-12-10
Thomson Csf

US3653745A
(en)

1970-06-11
1972-04-04
Rca Corp
Circuits for driving loads such as liquid crystal displays

JPS556916B1
(en)

1970-11-17
1980-02-20

JPS549040B1
(en)

1970-11-25
1979-04-20

US3697150A
(en)

1971-01-06
1972-10-10
Xerox Corp
Electro-optic systems in which an electrophoretic-like or dipolar material is dispersed throughout a liquid crystal to reduce the turn-off time

JPS53279B1
(en)

1971-02-25
1978-01-06

JPS5219106B1
(en)

1971-02-27
1977-05-26

US3881311A
(en)

1971-02-27
1975-05-06
Suwa Seikosha Kk
Driving arrangement for passive time indicating devices

CH529421A
(en)

1971-03-30
1972-10-15
Bbc Brown Boveri & Cie

Circuit arrangement for controlling liquid-crystalline light valves which can be addressed in matrix form

US4116543A
(en)

1971-05-03
1978-09-26
General Electric Company
Control electro-optical device utilizing liquid crystal

JPS5114434B1
(en)

1971-07-29
1976-05-10

US3786486A
(en)

1971-08-11
1974-01-15
Olivetti & Co Spa
Multiplex driving circuit

US3999180A
(en)

1971-10-04
1976-12-21
Rockwell International Corporation
Multiplex driver system for liquid crystal display

DE2151401C2
(en)

1971-10-15
1982-03-25
Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt
Liquid crystal matrix display unit – has control signal timing determined to avoid generation of cross effect

JPS527920B2
(en)

1971-10-20
1977-03-05

US3744049A
(en)

1971-11-16
1973-07-03
Optel Corp
Liquid crystal driving and switching apparatus utilizing multivibrators and bidirectional switches

US3723749A
(en)

1972-04-14
1973-03-27
Timex Corp
Driving circuit for liquid crystal displays

JPS4931297A
(en)

1972-07-21
1974-03-20

US3906290A
(en)

1973-01-16
1975-09-16
Mitsubishi Electric Corp
Display apparatus

JPS5311171B2
(en)

1973-02-09
1978-04-19

GB1502280A
(en)

1974-12-11
1978-03-01
Secr Defence
Liquid crystal displays

FR2312829A1
(en)

1975-05-30
1976-12-24
Commissariat Energie Atomique

PROCEDURE FOR CONTROL OF A LIQUID CRYSTAL DISPLAY CELL AND CORRESPONDING DEVICE

JPS6056026B2
(en)

1976-09-20
1985-12-07
松下電器産業株式会社

LCD panel drive method

US4109242A
(en)

1977-01-13
1978-08-22
Rca Corporation
Matrix address system using erase operation

GB2067811B
(en)

1980-01-16
1983-08-10
Standard Telephones Cables Ltd
Co-ordinate addressing of smetic display cells

US4505548A
(en)

1980-10-20
1985-03-19
At&T Bell Laboratories
Bistable liquid crystal twist cell

EP0236361A1
(en)

1985-09-06
1987-09-16
Consolidated Technology Pty. Ltd.
Method and apparatus for controlling a liquid crystal device

US4614940A
(en)

1985-10-21
1986-09-30
Southwest Research Institute
Micropower DC voltage indicator

NL8603151A
(en)

1986-12-11
1988-07-01
Philips Nv

CAMERA.

Family Cites Families (3)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US3322485A
(en)

1962-11-09
1967-05-30
Rca Corp
Electro-optical elements utilizing an organic nematic compound

US3499112A
(en)

1967-03-31
1970-03-03
Rca Corp
Electro-optical device

US3519330A
(en)

1967-09-14
1970-07-07
Rca Corp
Turnoff method and circuit for liquid crystal display element

1969

1969-07-10
US
US840731A
patent/US3575492A/en
not_active
Expired – Lifetime

1969-10-07
GB
GB49178/69A
patent/GB1286828A/en
not_active
Expired

1969-10-23
CA
CA065670A
patent/CA937291A/en
not_active
Expired

Also Published As

Publication number
Publication date

US3575492A
(en)

1971-04-20

CA937291A
(en)

1973-11-20

Contact information