EP0797182A1
Expired / Lapsed
EP
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Active matrix LCD with data holding circuit in each pixel
Assignee: Hitachi Ltd
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Filing: 1997-03-18
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Granted: —
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Expires: 2017-03-18
Abstract
Abstract An improved liquid crystal display apparatus for low power consumption is disclosed. The display apparatus is provided with the following within each of the regions surrounded by a plurality of scanning electrodes (3) and a plurality of signal electrodes (4): a display data holding circuit (5) connected to the corresponding scanning electrodes (3) and signal electrodes (4), for fetching and storing a display data from the signal electrode (4) in response to a scanning signal; a switching device connected to the display data holding circuit (5), its switching operation being controlled by the holding circuit (5); a display electrode (7) connected to the switching device.
Inventors
- 👤 Yoshiro Mikami
- 👤 Tetsuro Minemura
- 👤 Makoto Tsumura
- 👤 Kazuhiro Kuwabara
- 👤 Shinichi Komura
- 👤 Tatsuya Ohkubo
- 👤 Hideo Sato
- 👤 Shoichi Hirota
- 👤 Masaya Adachi
- 👤 Kazuhito Masuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 21:44
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/2007; G09G3/2011; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G09G3/3659; G09G3/3674; G09G3/3685; H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10F; H10F39/00; H10F39/80; H10F39/803; G09G2300/00; G09G2300/08; G09G2300/0809; G09G2300/0814; G09G2300/0828; G09G2300/0842; G09G2300/0857; G09G2300/0876; G09G2310/00; G09G2310/02; G09G2310/0243; G09G2310/0251; G09G2310/0264; G09G2310/027; G09G2320/00; G09G2320/02; G09G2320/0247; G09G2320/10; G09G2340/00; G09G2340/12; G09G2340/125; G09G3/3614
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
149 words
A liquid crystal display apparatus having a pair of substrates of which at least one substrate is transparent and a liquid crystal layer sandwiched between the substrates, comprising: a plurality of scanning electrodes (3) formed on one of the substrates; a plurality of signal electrodes (4) intersecting like a matrix with said plurality of scanning electrodes (3); wherein the display apparatus further comprises the followings within each of the regions surrounded by said plurality of scanning electrodes (3) and said plurality of signal electrodes (4); a display data holding circuit (5) connected to the corresponding scanning electrodes (3) and signal electrodes (4), for fetching and storing a display data from the signal electrode (4) in response to a scanning signal; a switching device connected to said display data holding circuit (5), its switching operation being controlled by the holding circuit; a display electrode (750) connected to said switching device.
Claim 2
Dependent Claim
53 words
A liquid crystal display apparatus according to claim 1, wherein an opposed electrode (770) which faces to said display electrode (750) is provided on the other substrate of said pair of substrates, and a common electrode (8) connected to a switching device within each of the regions is provided on one substrate thereof.
Claim 3
Dependent Claim
181 words
A liquid crystal display apparatus having a pair of substrates of which at least one substrate is transparent and a liquid crystal layer sandwiched between the substrates, comprising: a plurality of first scanning electrodes formed on one of the substrates; a plurality of signal electrodes (4) intersecting like a matrix with said plurality of first scanning electrodes; a plurality of second scanning electrodes provided along said first scanning electrodes or said signal electrodes (4); wherein the display apparatus further comprises the followings within each of the regions surrounded by said plurality of first scanning electrodes and said plurality of signal electrodes (4); a data holding circuit (5) connected to the corresponding first scanning electrodes, signal electrodes (4), and second scanning electrodes for fetching and storing a display data from the signal electrodes (4) in response to voltages applied to the first and the second scanning electrodes; a capacitor connected to said data holding circuit (5); a switching device connected to said capacitor, its switching operation being controlled by a voltage of the capacitor; a display electrode connected to said switching device.
Claim 4
Dependent Claim
165 words
A liquid crystal display apparatus having a pair of substrates of which at least one substrate is transparent and a liquid crystal layer sandwiched between the substrates, comprising: a plurality of scanning electrodes (3) formed on one of the substrates; a plurality of signal electrodes (4) intersecting like a matrix with each of said plurality of scanning electrodes (3); wherein the display apparatus further comprises the followings within each of the regions forming pixels surrounded by said plurality of scanning electrodes (3) and said plurality of signal electrodes (4); a sampling data holding circuit connected to the corresponding each of signal electrodes (4), for sampling and storing signal data from the signal electrode (4) in response to a scanning signal; a gray level selecting circuit connected to said sampling data holding circuit, for selecting the gray levels for the pixel in response to a state of the sampling of said sampling data holding circuit; a display electrode (750) connected to said gray level selecting circuit.
Claim 5
Dependent Claim
319 words
A liquid crystal display apparatus comprising: a liquid crystal layer including a liquid crystal constructing a plurality of pixels; a pair of boards facing to each other between which said liquid crystal layer is inserted, at least one of which is transparent; a plurality of scanning wires (G 1 -G n ) for transmitting scan pulses, distributed on one of said pair of boards; a plurality of signal wires (D 1 -D n ) for transmitting image data crossing with said plurality of scanning wires (G 1 -G n ) in a matrix geometry and distributed on one of said pair of boards; an AC voltage generation means for generating an AC voltage for driving said liquid crystal; and a timing signal generation means (500) for generating periodically timing signals in synchronization with said liquid crystal drive voltage generated by said AC voltage generation means, wherein a plurality of display area enclosed by a plurality of scanning wires (G 1 -G n ) and a plurality of signal wire (D 1 -D n ) having a display electrode (750) placed at one side of said pair of boards; a opposed electrodes (770) placed so as to face to said display electrode (750) through said liquid crystal layer, to which said liquid crystal drive voltage is applied by said AC voltage generation means; a switching device for driving pixels connected to said display electrode (750); a data hold means for holding said image data supplied from said signal wire (D 1 -D n ) in responsive to said scan pulse from said scanning wire (G 1 -G n ) and controlling said switching operation of said switching device for driving pixels in responsive to said held image data; and an initializing means for initializing said voltage applied between said display electrode (750) and said opposed electrode in responsive to said timing signal supplied by said timing signal generation means (500).
Claim 6
Dependent Claim
110 words
A liquid crystal display apparatus of Claim 1, 2 or 3, wherein said switching device for driving pixels is composed of a TFT device; a signal for switching operation is put into a gate terminal of said TFT device, a drain terminal of said TFT device is connected to a display electrode (750), and a source terminal is connected to a reference line (CNT) defining an average voltage of a liquid crystal drive voltage; and a timing signal (VTMG) of a timing signal generation means (500) is generated so synchronized with a time when said liquid crystal drive voltage generated by an AC voltage generation means reaches an average voltage.
Claim 7
Dependent Claim
135 words
A liquid crystal display apparatus of Claim 1, 2 or 3, wherein said switching device for driving pixels is composed of a TFT device; a signal for switching operation is put into a gate terminal of said TFT device, a drain terminal of said TFT device is connected to a display electrode (750), and a source terminal is connected to a reference line defining an average voltage of a liquid crystal drive voltage; a timing signal (VTMG) of a timing signal generation means (500) is generated so synchronized with a time when said liquid crystal drive voltage generated by an AC voltage generation means reaches an average voltage; and a generation of said timing signal (VTMG) is interrupted at a time when said voltage applied between a display electrode and a opposed electrode reaches zero.
References Cited (Backward Citations)
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