EP0336570A1
Expired / Lapsed
EP
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Method of driving display device
Assignee: Panasonic Holdings Corp
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Filing: 1989-03-10
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Granted: —
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Expires: 2009-03-10
Abstract
Abstract Disclosed is a driving method of an active matrix type liquid crystal display device having picture element electrodes connected in a matrix form to a first through capacity, switching elements connected to these picture element electrodes (these switching elements are also connected to the picture signal wire and scanning signal wire), and a display material held between the picture element electrodes and counter electrodes, wherein a first modulation signal is applied to the fire wire connected to the picture element electrodes through capacity, and a second modulation signal is applied to the counter electrodes. As a result, modulating the potential difference between the first wire and the counter electrodes, it is possible to effectively utilize the capacity coupling potential appearing at the picture element electrodes through the related capacity, so that (1) decrease of driving electric power, (2) improvement of display picture quality, and (3) enhancement of driving reliability may be achieved.
Inventors
- 👤 Seiichi Nagata
- 👤 Etsuya Takeda
- 👤 Tetsuya Kawamura
- 👤 Yutaka Nanno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 10:56
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G3/3655; G09G3/3659; H; H04; H04N; H04N3/00; H04N3/10; H04N3/12; H04N3/127; G09G2300/00; G09G2300/08; G09G2300/0876; G09G2320/00; G09G2320/02; G09G2320/0204; G09G2320/0219; G09G2320/0247
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
161 words
A method of driving a display device having picture element electrodes connected in matrix form to a first wire through capacity, switching elements connected to said picture element electrodes, these switching elements being also connected electrically between picture signal wires and scanning signal wires, and a display material held between the picture element electrodes and counter electrodes, wherein, by using the display device for driving this display material in alternating currents, the picture signal voltage is transmitted to the picture element electrode in the ON period of the switching elements, and a first modulation signal is applied to the first wire in the OFF period of the switching elements and a second modulation signal is also applied to the counter electrodes, thereby changing the potential of the counter electrode and picture element electrode, and the change of the potential and picture signal voltage are mutually superposed or canceled with each other so as to apply a voltage to the display material.
Claim 2
Independent Claim
161 words
A method of driving a display device having picture element electrodes connected in matrix form to a first wire through capacity, switching elements connected to said picture element electrodes, these switching elements being also connected electrically between picture signal wires and scanning signal wires, and a display material held between the picture element electrodes and counter electrodes, wherein, by using the display device for driving this display material in alternating currents, the picture signal voltage is transmitted to the picture element electrode in the ON period of the switching elements, and a first modulation signal is applied to the first wire in the OFF period of the switching elements and a second modulation signal is also applied to the counter electrodes, thereby changing the potential of the counter electrode and picture element electrode, and the change of the potential and picture signal voltage are mutually superposed or canceled with each other so as to apply a voltage to the display material.
Claim 3
Dependent Claim
100 words
A method of a driving display device according to claim 1, wherein the switching elements are thin film transistors (TFTs), the amplitudes of potential changes of the first modulation signal, second modulation signal and scanning signal are respectively defined as Ve, Vt, Vg, and the storage capacity, capacity between gate and drain, and capacity between source and drain are respectively supposed to be Cs, Cgd, Csd, and the relation of the amplitude of potential changes of the first modulation signal and second modulation signal is expressed as follows: Ve = {CpVt - CgdVg}/Cs Cp = Cs + Cgd + Csd
Claim 4
Dependent Claim
98 words
A method of driving a display device according to claim 1, wherein the switching elements are TFTs, the amplitudes of potential changes of the first modulation signal, second modulation signal and scanning signal are respectively defined as Ve, Vt, Vg, and the storage capacity, the capacity between gate and drain and the capacity between source and drain are supposed to be Cs, Cgd and Csd, respectively, and the relation of the amplitude of potential changes of the first modulation signal and second modulation signal is expressed as follows: Ve = CpVt/Cs Cp = Cs + Cgd + Csd
Claim 5
Dependent Claim
33 words
A method of a driving display device according to claim 1 or 2, wherein part of the potential of the first modulation signal is varied in the ON period of the switching elements.
Claim 6
Dependent Claim
22 words
A method of a driving display device according to claim 1, wherein the first and second modulation signals possess the same amplitude.
Claim 7
Dependent Claim
31 words
A method of a driving display device according to claim 1, wherein the second modulation signal is supplied from the (generation source of the) first modulation signal through an electrostatic capacity.
Claim 8
Dependent Claim
46 words
A method of a driving display device according to claim 1, wherein the potential of the counter electrodes is maintained in an electrically floating state, and the second modulation signal is supplied from the first modulation signal through the electrostatic capacity coupling inside the display device.
Claim 9
Dependent Claim
42 words
A method of a driving display device according to claim 1, wherein the mean potential of the counter electrodes is maintained at a specific potential, and the second modulation signal is supplied from the first modulation signal through an electrostatic capacity coupling.
Claim 10
Dependent Claim
46 words
A method of a driving display device according to claim 1, wherein the first wire is electrically composed so as to be shared with the scanning signal wire, and the first modulation signal is applied to the scanning signal wire in superposition on the scanning signal.
Claim 11
Dependent Claim
49 words
A method of a driving display device according to claim 9, wherein the first wire is electrically composed so as to be shared with the scanning signal wire, and the amplitude of the first modulation signal and the amplitude of the second modulation signal are equal to each other.
Claim 12
Dependent Claim
37 words
A method of a driving display device according to claim 9 or 10, wherein the amplitude of the first modulation signal is different (from the other periods) only in the specific period after application of canning signal.
References Cited (Backward Citations)
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