Patent US4951041A successfully refreshed from Google Patents.
US4951041A
Expired / Lapsed
US
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Driving method for thin film el display device and driving circuit thereof
Assignee: Sharp Corp
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Filing: 1988-07-06
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Granted: 1990-08-21
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Expires: 2008-07-06
Abstract
Abstract A driving method is described for thin film EL display devices having an EL layer interposed between scanning side electrodes and data side electrodes which are intersected to each other. The method comprises displaying frames formed by a line sequential drive in which voltage corresponding to display data is applied to the data side electrodes. Concurrently, write pulses which are negative and positive with respect to the data side electrodes are applied to the scanning side electrodes. Further the write pulses which are positive or negative with respect to the data side electrodes are applied to the scanning electrodes. The number of light emitting picture elements of the scanning side electrodes is previously detected from display data and the width of the write pulses, which are at least one of positive or negative is controlled in proportion to the number of the light emitting picture elements. Thus, the brightness of the light emitting picture elements is uniform due to the driving circuit thereof.
Inventors
- 👤 Shuji Inada
- 👤 Toshihiro Ohba
- 👤 Hiroshi Kishishita
- 👤 Hisashi Uede
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:08
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/22; G09G3/30; G09G2310/00; G09G2310/02; G09G2310/0264; G09G2310/0267; G09G2310/0275
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
247 words
A method for driving a matrix display device comprising scan side electrodes interposed in a matrix type format with data side electrodes, comprising the steps of: (a) repeatedly displaying a first frame, utilizing a line sequential drive, said display of said first frame being formed by, (1) applying voltage corresponding to display data to said data side electrodes, (2) applying write impulses, which are negative with respect to the voltage applied to said data side electrodes, to odd number lines of said scan side electrodes, and (3) applying write pulses, which are positive with respect to the voltage applied to said data side electrodes, to even number lines of said scan side electrodes; (b) repeatedly displaying a second frame, in an alternate manner with respect to said first frame, utilizing a line sequential drive, said display of said second frame being formed by, (1) applying voltage corresponding to display data to said data side electrodes, (2) applying write pulses, which are positive with respect to the voltage applied to said data side electrodes, to odd number lines of said scan side electrodes, and (3) applying write pulses, which are negative with respect to the voltage applied to said data side electrodes, to even number lines of said scan side electrodes; and (c) controlling the width of said positive and negative write pulses in proportion to the number of light emitting picture elements of each scanning side electrode line which has been previously detected from said display data.
Claim 2
Independent Claim
247 words
A method for driving a matrix display device comprising scan side electrodes interposed in a matrix type format with data side electrodes, comprising the steps of: (a) repeatedly displaying a first frame, utilizing a line sequential drive, said display of said first frame being formed by, (1) applying voltage corresponding to display data to said data side electrodes, (2) applying write impulses, which are negative with respect to the voltage applied to said data side electrodes, to odd number lines of said scan side electrodes, and (3) applying write pulses, which are positive with respect to the voltage applied to said data side electrodes, to even number lines of said scan side electrodes; (b) repeatedly displaying a second frame, in an alternate manner with respect to said first frame, utilizing a line sequential drive, said display of said second frame being formed by, (1) applying voltage corresponding to display data to said data side electrodes, (2) applying write pulses, which are positive with respect to the voltage applied to said data side electrodes, to odd number lines of said scan side electrodes, and (3) applying write pulses, which are negative with respect to the voltage applied to said data side electrodes, to even number lines of said scan side electrodes; and (c) controlling the width of said positive and negative write pulses in proportion to the number of light emitting picture elements of each scanning side electrode line which has been previously detected from said display data.
Claim 3
Dependent Claim
29 words
A method according to claim 1, wherein the width of write pulses is controlled to be between a maximum width and a minimum width which have been previously determined.
Claim 4
Dependent Claim
23 words
A method according to claim 1, wherein the width of write pulses is controlled by adjusting the rise time of the write pulses.
Claim 5
Dependent Claim
24 words
A method according to claim 1, wherein the number of light emitting picture elements is detected from non-illuminous signals included in a data signal.
Claim 6
Dependent Claim
23 words
A method according to claim 1, wherein the number of light emitting picture elements is detected by integrating pulses corresponding to non-illuminous signals.
Claim 7
Dependent Claim
284 words
A driving system for matrix display devices having a layer interposed between scanning side electrodes and data side electrodes which are intersected to each other, comprising: display means for displaying a first frame and a second frame alternatively and repeatedly; line sequential drive means for applying voltage corresponding to display data to the data side electrodes, for applying write pulses, which are negative with respect to the data side electrodes, to odd number lines of the scanning side electrodes, and for applying write pulses, which are positive with respect to the data side electrodes, to even lines of the scanning side electrodes, thereby forming said first frame; said line sequential drive means alternatively, with respect to said first frame, applying voltage corresponding to display data to the data side electrodes, applying write pulses, which are positive with respect to the data side electrodes, to the odd number lines, and applying write pulses, which are negative with respect to the data side electrodes, to the even number lines, thereby forming said second frame alternate to said first frame; first switching means for applying said write pulses, which are positive with respect to the data side electrodes, to the scanning side electrodes; second switching means for applying said write pulses, which are negative with respect to the data side electrodes, to the scanning side electrodes; detection means for previously detecting the number of light emitting picture elements in each scanning side electrode line from the display data; and control means for controlling at least either of said first or second switching means to control the width of the write pulses in proportion to the number of the light emitting picture elements detected by said detection means.
Claim 8
Dependent Claim
284 words
A driving system for matrix display devices having a layer interposed between scanning side electrodes and data side electrodes which are intersected to each other, comprising: display means for displaying a first frame and a second frame alternatively and repeatedly; line sequential drive means for applying voltage corresponding to display data to the data side electrodes, for applying write pulses, which are negative with respect to the data side electrodes, to odd number lines of the scanning side electrodes, and for applying write pulses, which are positive with respect to the data side electrodes, to even lines of the scanning side electrodes, thereby forming said first frame; said line sequential drive means alternatively, with respect to said first frame, applying voltage corresponding to display data to the data side electrodes, applying write pulses, which are positive with respect to the data side electrodes, to the odd number lines, and applying write pulses, which are negative with respect to the data side electrodes, to the even number lines, thereby forming said second frame alternate to said first frame; first switching means for applying said write pulses, which are positive with respect to the data side electrodes, to the scanning side electrodes; second switching means for applying said write pulses, which are negative with respect to the data side electrodes, to the scanning side electrodes; detection means for previously detecting the number of light emitting picture elements in each scanning side electrode line from the display data; and control means for controlling at least either of said first or second switching means to control the width of the write pulses in proportion to the number of the light emitting picture elements detected by said detection means.
Claim 9
Dependent Claim
25 words
A system according to claim 6, wherein the control means comprises a circuit for controlling a maximum and a minimum width of the write pulses.
Claim 10
Dependent Claim
26 words
A system according to claim 6, wherein the control means adjusts the width of the write pulses by adjusting the rise time of the write pulses.
Claim 11
Dependent Claim
26 words
A system according to claim 6, wherein the detection means detects the number of light emitting picture elements from non-illuminous signals included in a data signal.
Claim 12
Dependent Claim
22 words
A system according to claim 9, wherein the control means includes an integrating circuit which integrates pulses corresponding to the non-illuminous signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |