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WO2000060570A1 - Circuit de commande d'affichage a cristaux liquides - Google Patents

Circuit de commande d'affichage a cristaux liquides Download PDF

Info

Publication number
WO2000060570A1
WO2000060570A1 PCT/GB2000/001296 GB0001296W WO0060570A1 WO 2000060570 A1 WO2000060570 A1 WO 2000060570A1 GB 0001296 W GB0001296 W GB 0001296W WO 0060570 A1 WO0060570 A1 WO 0060570A1
Authority
WO
WIPO (PCT)
Prior art keywords
control circuit
circuit
controller
interface
control
Prior art date
Application number
PCT/GB2000/001296
Other languages
English (en)
Inventor
Nicholas James How
Original Assignee
Densitron Europe Limited
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 Densitron Europe Limited filed Critical Densitron Europe Limited
Priority to EP00917185A priority Critical patent/EP1086448A1/fr
Priority to AU38279/00A priority patent/AU3827900A/en
Publication of WO2000060570A1 publication Critical patent/WO2000060570A1/fr

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/14—Digital output to display device ; Cooperation and interconnection of the display device with other functional units
    • G06F3/147—Digital output to display device ; Cooperation and interconnection of the display device with other functional units using display 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
    • 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

Definitions

  • the present invention relates to control circuitry for LCD display devices and especially to those with low-power requirements.
  • Control circuits comprise a control chip and an associated memory, the chip being connected to relatively simple driver circuits for a LCD display. However, they consume a relatively large amount of power and are limited to the number of pixels they can control on a single display device. Also, they operate relatively slowly. The control chip can be moved outside the device, but this increases the complexity and cost of the external control required.
  • the present invention seeks to overcome or reduce one or more of the above disadvantages.
  • a control circuit for a liquid crystal display device comprising driver circuits for the device, each driver circuit having a respective memory section, characterised in that the control circuit further comprises a controller operatively connected between an external interface of the control circuit and the driver circuits.
  • the presence of the controller provides the advantage of on-board intelligence, whereas the incorporation of memory sections in the driver circuits permits the display to be self-refreshing. This has important implications for power consumption.
  • the controller is programmable, which enables an extremely flexible and useful device to be provided.
  • the controller may also provide functions associated with a transparent touch panel overlying the display device and/or a separate keyboard and/or separate switches.
  • the external interface may comprise a plurality of intelligent serial and or parallel connections. By reducing the number of input lines, less interference is caused to radio f equency signals.
  • a liquid crystal device incorporating a control circuit as set out above may have sleep, idle and active modes. In the idle mode, the controller and the interface are "off but the LCD driver circuits are still operative. Such an arrangement has the advantage of further reducing power consumption and leads to a longer battery life.
  • the contents of the memory sections of the driver circuits are preferably entered by a user/customer of the L.C.D. device.
  • a customer's microprocessor external to the control circuit, can communicate directly with the driver circuit memory sections.
  • the data entered by the user/customer may relate to the selection and configuration of graphic images or characters which may be shown by the display device.
  • Fig. 1 is a block circuit diagram of a first prior art control circuit
  • Fig. 2 is a block circuit diagram of a second prior art control circuit
  • Fig. 3 is a block circuit diagram of a first control circuit in accordance with the present invention.
  • Fig. 4 is a block circuit diagram of a second control circuit in accordance with the present invention.
  • Fig. 1 shows a prior art LCD control circuit 10 connected via interface 11 to an external microprocessor 100.
  • Graphic display panel 20 typically comprises 128 x 240 pixels which are driven at one edge by two MSM 5260 driver circuits 21, 22 and along a perpendicular edge by three MSM 5260 driver circuits, 23, 24, 25.
  • the abbreviation COM refers to common rows of pixels and the abbreviation COL refers to columns of vertical pixels.
  • the driver circuits are effectively "dumb” and typically consume 5 mA each. They are controlled by a display controller T6963 or HD44780 circuit 30 to which they are connected via standard drive output serial lines 32, 33.
  • the circuit 30 typically consumes 15 mA and has a fixed program.
  • Circuit 10 further includes a drive voltage circuit 40 and a backlight circuit 41.
  • Interface 11 is 12-way, comprising 8 data bits, represented by bi-directional data bus lines DB0-DB7, and 4 control lines, including the clock function and a power connection.
  • the data bus lines operate at a maximum rate of 5.5MHz.
  • Circuit 10 has an overall power consumption exceeding 200mW.
  • Fig. 2 shows a second prior art LCD control circuit 110 connected via interface 11 to external microprocessor 100.
  • Graphic display panel 120 is driven by column and row drive circuits 123, 121 which each incorporate a RAM memory section. The contents of the memory sections are only held while the power is on.
  • Interface 11 is 32-way comprising 16 address bits, 8 data bits and 8 control lines, including the clock function and a power connection.
  • the overall power consumption of circuit 110 itself is less than 20mW but it has no internal controller. This means that circuit 110 behaves completely differently from circuit 10 and that external control has to be provided. Circuit 110 does not itself incorporate any intelligence or functionality.
  • Figs. 1 and 2 constitute so-called embedded devices, that is they are limited to one type of application.
  • the power consumption of the arrangement of Fig. 1 is increased because data transfer to the memories has to occur every time the display is refreshed.
  • external control in particular memory control, has to be provided.
  • FIG. 3 shows a liquid crystal display control circuit 50 of a graphics terminal in accordance with a first embodiment of the present invention.
  • Graphic LCD display panel 60 has an i.e. HD 66523 driver circuit 61 at one edge and an i.e. HD66522 driver circuit 62 at a perpendicular edge.
  • the circuits 61, 62 have four grey scales and each consume less than 2 mA.
  • the controller 30 of prior art circuit 10 is replaced by a programmable integrated circuit 70 which may be constituted by a PIC16C64 device, which consumes less that 1 mA.
  • Software associated with the control circuit 70 is provided by the manufacturer.
  • Both circuits 61, 62 incorporate a respective RAM memory section as in circuit 110, but in circuit 50 they can be directly and remotely programmed by a user/customer solely by means of the data bus of the external microprocessor 100 so that panel 60 can indicate a desired display.
  • circuit 70 serves to forward communications between microprocessor 100 and circuits 61, 62 without change or to intelligently modify the data according to the internal program.
  • Another distinguishing feature of circuits 61, 62 when in circuit 50 is that their memories are not cleared when the system is otherwise dormant.
  • Circuit 70 has several memory blocks including a static block relating to functionality and a plurality of register blocks which are programmable by the user, for example to determine when the system is to be dormant.
  • a data input buffer circuit is provided between the customer's microprocessor bus and the internal microprocessor bus of the circuit 50.
  • circuit 50 across interface 11 are substantially the same as those of the circuit 10 of Fig. 1, except that processing can now occur at a frequency of a maximum of 12MHz rather than the previous maximum of 5.5MHz. This enables the circuit to directly replace existing circuits without requiring any changes to the customer's electronic equipment; software changes, however, need to be made.
  • the total current consumption is less than 5 mA which has important power supply implications, since the display circuit can be operated over telephone lines rather than requiring a battery or a mains connection.
  • the electricity supply incorporates a circuit which transforms the line voltage into five different voltages required to operate the control circuit. Because of its low power requirement and its flexibility, the circuit of the present invention may be used with larger display panels e.g. up to 480 x 640 pixels.
  • circuit of Fig. 3 is not of the "embedded" type, i.e. it is not dedicated to a single application but can be programmed for a wide range of alternative uses.
  • Circuit 150 in accordance with a second embodiment of the present invention, is shown in Fig. 4 as an arrangement embedded in a touch panel display device.
  • Circuit 150 comprises a programmable integrated circuit 170 which may be constituted by a PIC16LC874 device. It typically comprises two blocks, viz a static block with programmed functionality and a register block which a user can program, e.g. to determine the conditions under which control circuit 150 is to be dormant.
  • a transparent touch panel input device 80 Overlying the display panel 60 is a transparent touch panel input device 80 of the type which produces an output depending upon the location at which a user's finger or stylus contacts the panel.
  • a transparent touch panel input device 80 of the type which produces an output depending upon the location at which a user's finger or stylus contacts the panel.
  • One exemplary application is as a so-called "palm-pilot" in a Personal Data Assistant device.
  • the touch panel 80 may be supplemented or replaced by switches along an edge of the display panel 60, and/or by a keyboard. Indicators such as LEDs may also be provided to indicate different operational states. A light sensor may also be provided.
  • the interface 1 1 may be 12-way parallel as with control circuit 10. Alternatively, it may be 5-way serial, viz two serial data lines and two control lines in addition to a clock input line. Such an arrangement is particularly advantageous in wireless communication applications because fewer wires produce less interference and can be more easily shielded.
  • a display device incorporating circuit 150 may have three states, viz: active, idle and sleep.
  • the PIC wakes up from idle mode or sleep mode if either of the following wake-up events happens:
  • the PIC remains in idle or sleep mode at all other times.
  • - are expandable, consume lower power, especially compared to the device of Fig. 1, combine intelligence with self-refreshing memories for the display, offer enhanced pixel control, and offer an increased pixel count.
  • Device 5 is of the type shown in Fig. 3 and has the following features: full Bit Map graphic control, 4 grey scale (from 32 total), blinking, inverse video, 2 sleep modes, SPI or 8 bit parallel, multiple window control, backlight control.
  • Device 6 is of the type shown in Fig. 4 and has the following features: full Bit Map graphic control, 4 grey scale, 2 sleep modes, SPI or 8 bit parallel, multiple window control, 8 bit (512y x 512x point) analogue resistive touch decoder.

Landscapes

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

Abstract

L'invention concerne un circuit de commande (50, 150) pour un dispositif à affichage à cristaux liquides (60). Ce circuit comprend des circuits d'attaque à affichage à cristaux liquides (61, 62) comprenant des mémoires correspondantes et un contrôleur programmable (70, 170) relié de manière opérationnelle aux circuits d'attaque et un microprocesseur externe (100) dans une interface externe (11). Le dispositif peut comprendre un écran tactile transparent (80) recouvrant le dispositif d'affichage (60). Cette interface (11) comprend des connexions séries et/ou parallèles intelligentes comprenant des lignes de données, de commande et d'horloge. Un dispositif comprenant le circuit de commande présente des modes « sommeil », « repos » et « actif » . Les circuits de commande (61, 62) fonctionnent sur le mode « repos ».
PCT/GB2000/001296 1999-04-06 2000-04-06 Circuit de commande d'affichage a cristaux liquides WO2000060570A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP00917185A EP1086448A1 (fr) 1999-04-06 2000-04-06 Circuit de commande d'affichage a cristaux liquides
AU38279/00A AU3827900A (en) 1999-04-06 2000-04-06 Lcd control circuitry

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9907849.5 1999-04-06
GBGB9907849.5A GB9907849D0 (en) 1999-04-06 1999-04-06 LCD control circuitry

Publications (1)

Publication Number Publication Date
WO2000060570A1 true WO2000060570A1 (fr) 2000-10-12

Family

ID=10851029

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2000/001296 WO2000060570A1 (fr) 1999-04-06 2000-04-06 Circuit de commande d'affichage a cristaux liquides

Country Status (4)

Country Link
EP (1) EP1086448A1 (fr)
AU (1) AU3827900A (fr)
GB (1) GB9907849D0 (fr)
WO (1) WO2000060570A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1164570A4 (fr) * 1999-11-29 2003-01-02 Seiko Epson Corp Pilote a ram integree, unite d'affichage associee audit pilote et dispositif electronique
KR100408393B1 (ko) * 2001-01-15 2003-12-06 삼성전자주식회사 액정 표시 장치의 패널 구동 장치 및 패널 구동 시스템
EP1164571A4 (fr) * 1999-11-29 2004-03-03 Seiko Epson Corp Pilote a ram integree, unite d'affichage associee audit pilote et dispositif electronique
KR100551728B1 (ko) * 2002-07-11 2006-02-13 비오이 하이디스 테크놀로지 주식회사 액정 모니터 제조를 자동화할 수 있는 액정표시장치
US12164707B2 (en) 2022-06-21 2024-12-10 GE Precision Healthcare LLC Methods and systems for a rotary user interface for touchscreen displays

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4710766A (en) * 1983-08-25 1987-12-01 Societe Francaise D'equipements Pour La Navigation Aerienne Device for displaying symbols by means of a liquid crystal matrix
EP0655725A1 (fr) * 1993-11-30 1995-05-31 Rohm Co., Ltd. Méthode et appareil pour réduire la consommation d'énergie dans un affichage matriciel
US5703616A (en) * 1993-05-13 1997-12-30 Casio Computer Co., Ltd. Display driving device
US5726677A (en) * 1992-07-07 1998-03-10 Seiko Epson Corporation Matrix display apparatus, matrix display control apparatus, and matrix display drive apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4710766A (en) * 1983-08-25 1987-12-01 Societe Francaise D'equipements Pour La Navigation Aerienne Device for displaying symbols by means of a liquid crystal matrix
US5726677A (en) * 1992-07-07 1998-03-10 Seiko Epson Corporation Matrix display apparatus, matrix display control apparatus, and matrix display drive apparatus
US5703616A (en) * 1993-05-13 1997-12-30 Casio Computer Co., Ltd. Display driving device
EP0655725A1 (fr) * 1993-11-30 1995-05-31 Rohm Co., Ltd. Méthode et appareil pour réduire la consommation d'énergie dans un affichage matriciel

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1164570A4 (fr) * 1999-11-29 2003-01-02 Seiko Epson Corp Pilote a ram integree, unite d'affichage associee audit pilote et dispositif electronique
EP1164571A4 (fr) * 1999-11-29 2004-03-03 Seiko Epson Corp Pilote a ram integree, unite d'affichage associee audit pilote et dispositif electronique
US7034792B2 (en) 1999-11-29 2006-04-25 Seiko Epson Corporation RAM-incorporated driver, and display unit and electronic equipment using the same
US7050032B2 (en) 1999-11-29 2006-05-23 Seiko Epson Corporation Ram-incorporated driver, and display unit and electronic equipment using the same
KR100408393B1 (ko) * 2001-01-15 2003-12-06 삼성전자주식회사 액정 표시 장치의 패널 구동 장치 및 패널 구동 시스템
KR100551728B1 (ko) * 2002-07-11 2006-02-13 비오이 하이디스 테크놀로지 주식회사 액정 모니터 제조를 자동화할 수 있는 액정표시장치
US12164707B2 (en) 2022-06-21 2024-12-10 GE Precision Healthcare LLC Methods and systems for a rotary user interface for touchscreen displays

Also Published As

Publication number Publication date
EP1086448A1 (fr) 2001-03-28
AU3827900A (en) 2000-10-23
GB9907849D0 (en) 1999-06-02

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