WO1993006586A1 - Procede d'adressage d'une cellule a cristaux liquides du type a matrice - Google Patents

Procede d'adressage d'une cellule a cristaux liquides du type a matrice Download PDF

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Publication number
WO1993006586A1
WO1993006586A1 PCT/GB1992/001464 GB9201464W WO9306586A1 WO 1993006586 A1 WO1993006586 A1 WO 1993006586A1 GB 9201464 W GB9201464 W GB 9201464W WO 9306586 A1 WO9306586 A1 WO 9306586A1
Authority
WO
WIPO (PCT)
Prior art keywords
blanking
select
pulses
pulse
addressing
Prior art date
Application number
PCT/GB1992/001464
Other languages
English (en)
Inventor
Paul Surguy
Original Assignee
Thorn Emi Plc
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 Thorn Emi Plc filed Critical Thorn Emi Plc
Priority to JP05505857A priority Critical patent/JP3122137B2/ja
Priority to CA002119459A priority patent/CA2119459C/fr
Priority to EP92916450A priority patent/EP0604448B1/fr
Priority to DE69224292T priority patent/DE69224292T2/de
Publication of WO1993006586A1 publication Critical patent/WO1993006586A1/fr

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3622—Control of matrices with row and column drivers using a passive matrix
    • G09G3/3629—Control of matrices with row and column drivers using a passive matrix using liquid crystals having memory effects, e.g. ferroelectric liquid crystals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0202—Addressing of scan or signal lines
    • G09G2310/0205—Simultaneous scanning of several lines in flat panels
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G09G2310/061—Details of flat display driving waveforms for resetting or blanking
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G09G2310/065—Waveforms comprising zero voltage phase or pause
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/02—Improving the quality of display appearance
    • G09G2320/0247—Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes

Definitions

  • the present invention relates to a method for addressing a matrix-type liquid crystal cell and the method has particular, although not exclusive, relevance to such cells as are employed within visual displays and the like.
  • One known method of addressing a matrix-array type liquid crystal cell is that disclosed in UK Patent Number GB 2,173,336B.
  • the cell is treated as a matrix of orthogonal row and column electrodes. Waveforms are applied to both the rows and columns in order to selectively switch the individual elements into either the dark (non-light transmitting) state, or the light transmitting state.
  • the column electrodes may be applied two types of data waveform: "on” or "unchanged”. Synchronised to these waveforms are those waveforms which are applied to the row electrodes, these are termed “select”, “non-select” and “blank”. At any one time, only one row electrode has the “select” waveform applied to it, and at least one other row electrode has the “blank” waveform applied to it. All the remaining row electrodes have the "non-select” waveform applied thereto.
  • the scheme mentioned above operates in the following manner: Data waveforms are applied to the column electrodes in order to create the desired pattern on the row electrode to which the select waveform is applied.
  • this electrode will previously have been blanked by application thereto of the blanking waveform. This has the effect of setting that row into the dark (or "off") state, regardless of whether it combines with an "on” or “unchanged” data waveform all of the elements of the display common to that electrode will be switched into the dark state, prior to the application to that row, of the select waveform.
  • a row electrode Contemporaneously with the application of the data waveform, a row electrode has the blank waveform applied to it. It will be apparent to those skilled in the art that with any such system it is a requirement to maintain dc compensation, or charge balancing, that is both the "on" and “unchanged” data waveforms must have no dc component.
  • the system exemplified in GB 2,173,336B however suffers from the shortcomings that the response time of the liquid crystal material is slowed down if the blanking waveform is applied to a row electrode only shortly before the application of the select waveform to that same row electrode.
  • a method of addressing a matrix-array type liquid crystal cell including ferroelectric liquid crystal material comprising a plurality of pixels which are defined by areas of overlap between members of a first set of electrodes on one side of the material and members of a second set of electrodes, oriented orthogonal to the first set, on the other side of the material; in which method the pixels of the array are addressed on a line-by-line basis after blanking, wherein unipolar blanking pulses are applied to the members of the first set of electrodes to effect blanking and wherein for selective addressing of the pixels, unipolar select pulses are applied serially to the members of the first set of electrodes while charge-balanced bipolar data pulses are applied in parallel to the members of the second set, the positive going parts of the data pulses being synchronised with the select pulses for one data significance and the negative going parts of the data pulses being synchronised with the select pulses for the other data significance, wherein the polarities of the select and blank
  • the present invention provides a method for addressing a matrix-array type liquid crystal cell whereby the potential for the response time of the liquid crystal material being slowed down is reduced by providing a blanking pulse whose amplitude and duration may be modified as desired, within working limits.
  • Figure 1 illustrates schematically a conventional matrix-array type cell
  • Figure 2 illustrates graphically the various waveforms which may be applied to row and column electrodes for both the prior art and the present invention
  • Figure 3 illustrates schematically a comparison between the general form of a blanking waveform and a select waveform
  • Figures A is a schematic illustration of the modified blanking waveform occurring at the cell in accordance with the present invention.
  • a matrix-array type liquid crystal cell shown generally as 2 comprises an array of overlapping orthogonal row 4 and column 6 electrodes between which is disposed liquid crystal material
  • the method of addressing one particular pixel 3 within cell 2, which is defined by an area of overlap between a row electrode 4 and a column electrode 6 is as follows: Before any addressing of the cell 2 with display data may take place, the row 4 of which the one particular pixel 3 forms a part must first be set into the dark state state. This is achieved by applying a blanking waveform 16 thereto. This is necessary to ensure that the whole row 4 is set into a predetermined state from which display data addressing may take place.
  • the desired display data waveform 8 or 10, say 8 is applied to the desired column electrode 6 which intersects or overlies pixel 3. Simultaneously, the corresponding electrode 4 which overlies pixel 3 has applied thereto the select waveform 12.
  • V is the voltage of the data waveform 8,10 and T is the time duration of a waveform having this voltage amplitude.
  • This modification is achieved by a reduction in the amplitude of the blanking pulse 16 such that it is less than the amplitude, V , of the following select pulse 12. However, there is then preferably an extension of the duration of the blanking pulse 16 as compared with the duration, T, of this select pulse 12.
  • the areas defined by the select 12 and blanking pulses 16 are equal, although the area defined by the select pulse may never be less than that of the preceding blanking pulse.
  • the blanking pulse 16 has an i plitude V /n and duration mT as compared with select pulse 12 which has amplitude V and duration T.
  • Figure 5 illustrates the switching characteristics of the cell 2 by plotting the voltage applied thereto against the time for which this voltage is applied. It is known to those skilled in the art that generally, the magnitude of the blanking pulse 16 is greater than is actually required in order to set each pixel 3 into the "dark" state. Because of this, then some relaxation period immediately subsequent to the application of the blanking pulse will be necessary before addressing takes place. Thus, by reducing the amplitude of the blanking waveform 16 in accordance with the present invention, yet still remaining within the switching boundary of figure 5, the need for a relaxation period may be obviated. It will be understood that the limit of reduction of the blanking waveform 16 amplitude and temporal extension will be governed by the requirement that V /n > V .
  • n and m may be used, although integer values have been found convenient. There is no necessity for n and m to be equal but m must be greater than or equal to n.
  • n and m are chosen to be equal, it is preferable that values of greater than or equal to 2 are chosen; this is because a value of less than 2 would lead to the blanking waveform 16 amplitude and duration being such that it approaches that of
  • V /n V /n>V, because it can be seen that if the amplitude of the s d r blanking pulse 16, V /n falls below V , then there will be some time during the blanking period when the voltage changes polarity, and this change in polarity may promote switching in the opposite direction away from the desired blank (or dark) state- Hence the limit V /n > V,. s d
  • the amplitude of the blanking pulse 16 must be greater than or equal to that of the data pulses 8,10. This is so that during application of the blanking pulse 16 there is no excursion of the difference between blanking pulse 16 and either data pulse 8 or 10 to a polarity opposite that of blanking pulse 16.
  • the present invention provides a method of addressing a matrix-array type liquid crystal cell having a modified blanking waveform whereby the response time of the liquid is maintained.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

Procédé d'adressage d'un affichage à cristaux liquides du type à matrice consistant à occulter toutes les lignes de pixels situées à l'intérieur de l'affichage à cristaux liquides avant l'adressage à afficher. La réduction de l'amplitude de l'impulsion d'occultation (16) permet de l'appliquer à une ligne particulière se trouvant huit lignes ou davantage en-dessous avant application de l'impulsion de sélection nécessaire (12) à l'affichage des renseignements. Ceci se traduit par une maximisation de luminosité de l'affichage et par une réduction de scintillement.
PCT/GB1992/001464 1991-09-21 1992-08-07 Procede d'adressage d'une cellule a cristaux liquides du type a matrice WO1993006586A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP05505857A JP3122137B2 (ja) 1991-09-21 1992-08-07 マトリックス配列型液晶セルをアドレスする方法
CA002119459A CA2119459C (fr) 1991-09-21 1992-08-07 Methode d'adressage pour cellule a cristaux liquides de reseau matriciel
EP92916450A EP0604448B1 (fr) 1991-09-21 1992-08-07 Procede d'adressage d'une cellule a cristaux liquides du type a matrice
DE69224292T DE69224292T2 (de) 1991-09-21 1992-08-07 Verfahren zum steuern einer flüssigkristallanseigematrix

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB919120210A GB9120210D0 (en) 1991-09-21 1991-09-21 Method of addressing a matrix-array type liquid crystal cell
GB9120210.1 1991-09-21

Publications (1)

Publication Number Publication Date
WO1993006586A1 true WO1993006586A1 (fr) 1993-04-01

Family

ID=10701816

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1992/001464 WO1993006586A1 (fr) 1991-09-21 1992-08-07 Procede d'adressage d'une cellule a cristaux liquides du type a matrice

Country Status (6)

Country Link
EP (1) EP0604448B1 (fr)
JP (1) JP3122137B2 (fr)
CA (1) CA2119459C (fr)
DE (1) DE69224292T2 (fr)
GB (1) GB9120210D0 (fr)
WO (1) WO1993006586A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5506599A (en) * 1993-09-01 1996-04-09 Sony Corporation Active matrix liquid crystal display apparatus with varying pulse widths and a constant pulse width-pulse height product

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0931816B1 (fr) 1996-10-09 2005-04-13 Nippon Zeon Co., Ltd. Composition a base d'un polymere de norbornene
KR20000052823A (ko) 1996-10-29 2000-08-25 나카노 카쯔히코 변성 열가소성 노르보르넨계 중합체 및 그 제조방법
US6613855B1 (en) 1997-04-09 2003-09-02 Sanyo Chemical Industries, Ltd. Polymerizable resin, and cured resins, insulators, components of electrical appliances, and electrical appliances made by using the same
JP3890738B2 (ja) 1998-04-09 2007-03-07 日本ゼオン株式会社 軟質重合体配合樹脂組成物
JP6078215B2 (ja) * 2013-06-29 2017-02-08 義夫 遠山 バッティング練習装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3501982A1 (de) * 1984-01-23 1985-07-25 Canon K.K., Tokio/Tokyo Verfahren zum ansteuern einer lichtmodulationsvorrichtung
GB2173336A (en) * 1985-04-03 1986-10-08 Stc Plc Addressing liquid crystal cells

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3501982A1 (de) * 1984-01-23 1985-07-25 Canon K.K., Tokio/Tokyo Verfahren zum ansteuern einer lichtmodulationsvorrichtung
GB2173336A (en) * 1985-04-03 1986-10-08 Stc Plc Addressing liquid crystal cells

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5506599A (en) * 1993-09-01 1996-04-09 Sony Corporation Active matrix liquid crystal display apparatus with varying pulse widths and a constant pulse width-pulse height product

Also Published As

Publication number Publication date
JPH06511095A (ja) 1994-12-08
JP3122137B2 (ja) 2001-01-09
DE69224292D1 (de) 1998-03-05
DE69224292T2 (de) 1998-07-23
EP0604448A1 (fr) 1994-07-06
EP0604448B1 (fr) 1998-01-28
CA2119459A1 (fr) 1993-04-01
CA2119459C (fr) 2002-11-26
GB9120210D0 (en) 1991-11-06

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