US5235253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin-film electroluminescent device drive circuit
Assignee: Fujifilm Business Innovation Corp
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Filing: 1992-12-14
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Granted: 1993-08-10
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Expires: 2012-12-14
Abstract
Abstract A thin film electroluminescent EL device drive circuit which is capable of applying an AC pulse signal to EL elements contained in the EL device to thereby perform high luminance drive of the EL devices and realize AC pulse drive. With such a drive circuit, it is possible to reduce supply current capacity and power consumption.
Inventors
- 👤 Yoshihide Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:16
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/22; G09G3/30; H; H05; H05B; H05B44/00; G09G2300/00; G09G2300/08; G09G2300/0809; G09G2300/0842; Y; Y02; Y02B; Y02B20/00; Y02B20/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
136 words
A thin film electroluminescent device drive circuit comprising: an electroluminescent means for emitting light in response to an applied charge, said electroluminescent means having first and second terminals, said first terminal being connected to a predetermined constant voltage; a storage capacitor, having a position terminal and a negative terminal, for accumulating a charge to supply to said electroluminescent means to provide high power to said electroluminescent means; a DC power source for charging said storage capacitor; and means for controlling the charge and discharge of said storage capacitor so as to drive said electroluminescent means with an AC pulse drive signal, said AC pulse drive signal being produced by repeating alternate connection of the positive terminal and the negative terminal of said storage capacitor to said electroluminescent means after each time said storage capacitor is charged.
Claim 2
Dependent Claim
136 words
A thin film electroluminescent device drive circuit comprising: an electroluminescent means for emitting light in response to an applied charge, said electroluminescent means having first and second terminals, said first terminal being connected to a predetermined constant voltage; a storage capacitor, having a position terminal and a negative terminal, for accumulating a charge to supply to said electroluminescent means to provide high power to said electroluminescent means; a DC power source for charging said storage capacitor; and means for controlling the charge and discharge of said storage capacitor so as to drive said electroluminescent means with an AC pulse drive signal, said AC pulse drive signal being produced by repeating alternate connection of the positive terminal and the negative terminal of said storage capacitor to said electroluminescent means after each time said storage capacitor is charged.
Claim 3
Dependent Claim
134 words
A thin film electroluminescent device drive circuit comprising: an electroluminescent means for emitting light in response to an applied charge, said electroluminescent means having first and second terminals, said first terminal being connected to a ground; a storage capacitor, having a positive terminal and a negative terminal, for accumulating a charge to supply to said electroluminescent means to provide high power to said electroluminescent means; a DC power source for charging said storage capacitor; and means for controlling the charge and discharge of said storage capacitor so as to drive said electroluminescent means with an AC pulse drive signal, said AC pulse drive signal being produced by repeating alternate connection of the positive terminal and the negative terminal of said storage capacitor to said electroluminescent means after each time said storage capacitor is charged.
Claim 4
Dependent Claim
134 words
A thin film electroluminescent device drive circuit comprising: an electroluminescent means for emitting light in response to an applied charge, said electroluminescent means having first and second terminals, said first terminal being connected to a ground; a storage capacitor, having a positive terminal and a negative terminal, for accumulating a charge to supply to said electroluminescent means to provide high power to said electroluminescent means; a DC power source for charging said storage capacitor; and means for controlling the charge and discharge of said storage capacitor so as to drive said electroluminescent means with an AC pulse drive signal, said AC pulse drive signal being produced by repeating alternate connection of the positive terminal and the negative terminal of said storage capacitor to said electroluminescent means after each time said storage capacitor is charged.
Claim 5
Dependent Claim
20 words
The thin film electroluminescent device drive circuit as defined in claim 2 wherein said control switches are thin film transistors.
Claim 6
Dependent Claim
344 words
A thin film electroluminescent device drive circuit comprising: a DC power source; a storage capacitor having a positive and a negative terminal, said storage capacitor being charged by said DC power source; an electroluminescent means having first and second terminals, for emitting light in response to an applied charge, said first terminal being connected to a ground; a first control switch for connecting said DC power source and the positive terminal of said storage capacitor; a second control switch for connecting the negative terminal of said storage capacitor to a ground; a third control switch for connecting the positive terminal of said storage capacitor to a ground; a fourth control switch for connecting the positive terminal of said storage capacitor to said second terminal of said electroluminescent means; a fifth control switch for connecting the negative terminal of said storage capacitor to said second terminal of said electroluminescent means; a sixth control switch for connecting said second terminal of said electroluminescent means to a ground; and means for controlling the charge and discharge of said storage capacitor so as to drive said electroluminescent means with an AC pulse drive signal by: turning-off said third, fourth and fifth control switches and turning-on said first, second and sixth switches to charge said storage capacitor and to reset said electroluminescent means; turning-off said first and sixth control switches and turning-on said fourth control switch to supply a positive charge of said storage capacitor to said electroluminescent means to perform a positive polarity drive; turning-off said fourth control switch and turning-on said first and sixth control switches to discharge said electroluminescent means and to charge said storage capacitor with said DC power source, turning-off said sixth, first and second control switches and turning-on said fifth and third control switches to supply a negative charge of said storage capacitor to perform a negative polarity drive, and turning-off said fifth and third control switches and turning on said sixth, first and second control switches to discharge said electroluminescent means and to charge said storage capacitor with said DC power source.
Claim 7
Dependent Claim
344 words
A thin film electroluminescent device drive circuit comprising: a DC power source; a storage capacitor having a positive and a negative terminal, said storage capacitor being charged by said DC power source; an electroluminescent means having first and second terminals, for emitting light in response to an applied charge, said first terminal being connected to a ground; a first control switch for connecting said DC power source and the positive terminal of said storage capacitor; a second control switch for connecting the negative terminal of said storage capacitor to a ground; a third control switch for connecting the positive terminal of said storage capacitor to a ground; a fourth control switch for connecting the positive terminal of said storage capacitor to said second terminal of said electroluminescent means; a fifth control switch for connecting the negative terminal of said storage capacitor to said second terminal of said electroluminescent means; a sixth control switch for connecting said second terminal of said electroluminescent means to a ground; and means for controlling the charge and discharge of said storage capacitor so as to drive said electroluminescent means with an AC pulse drive signal by: turning-off said third, fourth and fifth control switches and turning-on said first, second and sixth switches to charge said storage capacitor and to reset said electroluminescent means; turning-off said first and sixth control switches and turning-on said fourth control switch to supply a positive charge of said storage capacitor to said electroluminescent means to perform a positive polarity drive; turning-off said fourth control switch and turning-on said first and sixth control switches to discharge said electroluminescent means and to charge said storage capacitor with said DC power source, turning-off said sixth, first and second control switches and turning-on said fifth and third control switches to supply a negative charge of said storage capacitor to perform a negative polarity drive, and turning-off said fifth and third control switches and turning on said sixth, first and second control switches to discharge said electroluminescent means and to charge said storage capacitor with said DC power source.
Claim 8
Dependent Claim
29 words
A thin film EL device drive circuit as defined in claim 1 wherein a capacity of said storage capacitor is larger than a load capacity of said electroluminescent means.
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) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |