EP0535885A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Driver circuit for a display device and method of driving such device
Assignee: NEC Corp
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Filing: 1992-09-28
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Granted: —
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Expires: 2012-09-28
Abstract
Abstract A driver circuit for an electroluminescent display device has first and second clock pulse generator circuits (1,2). The first and second clock pulses are applied to a gate circuit (3) to allow the first clock pulse to pass when both the first and second clock pulses are a high level. From the output of the gate circuit, a combination of a transistor (41) and an inductance (42) generate a high voltage pulse. The high voltage pulse is rectified in a triple voltage rectifying circuit (43) to output a high voltage output for driving the display device such as EL elements, and the high voltage output can be reset by a low frequency pulse output from a discharge circuit (50). As a result, no inverter is required, and a small-sixed and light-weight driver circuit is achieved with a long luminescence life of the EL elements and without noises offensive to the ear. <IMAGE>
Inventors
- 👤 Motoyoshi C/O Nec Corporation Komoda
- 👤 Minoru C/O Sangikyo Corporation Katsumata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 17:54
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/06; G09G3/12; H; H05; H05B; H05B44/00; Y; Y02; Y02B; Y02B20/00; Y02B20/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
137 words
A driver circuit for applying a driving voltage to a display device, comprising: first clock generator means (1) for generating a first clock pulse having a first frequency; second clock generator means (2) for generating a second clock pulse having a second frequency lower than the first frequency; gate means (3) for receiving the first and second clock pulses and allowing the first clock pulse to pass when the second clock pulse is present; high voltage pulse generation means (41, 42) for generating a high voltage pulse in synchronism with the pulse output from the gate means; voltage multiplication rectifying means (43) for performing a voltage multiplication rectifying of the high voltage pulse to obtain a high voltage output; and reset means (50) for resetting the voltage multiplication rectifying means when the second clock pulse is off.
Claim 2
Dependent Claim
137 words
A driver circuit for applying a driving voltage to a display device, comprising: first clock generator means (1) for generating a first clock pulse having a first frequency; second clock generator means (2) for generating a second clock pulse having a second frequency lower than the first frequency; gate means (3) for receiving the first and second clock pulses and allowing the first clock pulse to pass when the second clock pulse is present; high voltage pulse generation means (41, 42) for generating a high voltage pulse in synchronism with the pulse output from the gate means; voltage multiplication rectifying means (43) for performing a voltage multiplication rectifying of the high voltage pulse to obtain a high voltage output; and reset means (50) for resetting the voltage multiplication rectifying means when the second clock pulse is off.
Claim 3
Dependent Claim
38 words
The driver circuit as claimed in claim 1, wherein the gate means is an AND gate (3), and the AND gate outputs the first clock pulse when both the first and second clock pulses are a high level.
Claim 4
Dependent Claim
47 words
The driver circuit as claimed in claim 1 or 2, wherein the high voltage pulse generation means includes a coil (42) connected to a power source and a MOSFET (41) connected to the coil, and the output of the gate means (3) is input to the MOSFET.
Claim 5
Dependent Claim
24 words
The driver circuit as claimed in claim 1, 2 or 3, wherein the voltage multiplication rectifying means (43) is a triple voltage rectifying circuit.
Claim 6
Dependent Claim
78 words
The driver circuit as claimed in any of claims 1 to 4, wherein the reset means includes: first transistor means (51) having a base and a collector for inputting the second clock pulse at the base from the second clock generator means; and second transistor means (52) having a base connected to the collector of the first transistor means and a power source via a resistor and a collector connected to an output terminal of the driver circuit.
Claim 7
Independent Claim
88 words
A method of driving a display device, comprising the steps of: generating a first clock pulse having a first frequency; generating a second clock pulse having a second frequency lower than the first frequency; allowing the first clock pulse to pass responsive to the second clock pulse; generating a high voltage pulse in synchronism with the passed first clock pulse; performing a voltage multiplication of the high voltage pulse to obtain a high voltage output; and resetting the voltage multiplication operation when the second clock pulse is off.
Claim 8
Independent Claim
88 words
A method of driving a display device, comprising the steps of: generating a first clock pulse having a first frequency; generating a second clock pulse having a second frequency lower than the first frequency; allowing the first clock pulse to pass responsive to the second clock pulse; generating a high voltage pulse in synchronism with the passed first clock pulse; performing a voltage multiplication of the high voltage pulse to obtain a high voltage output; and resetting the voltage multiplication operation when the second clock pulse is off.
Claim 9
Dependent Claim
107 words
An electroluminescent display device provided with a driver circuit for applying a driving voltage to the display device, the driver circuit comprising: first clock generator means (1) for generating a first clock pulse having a first frequency; second clock generator means (2) for generating a second clock pulse having a second frequency lower than the first frequency; gate means (3) for receiving the first and second clock pulses and allowing the first clock pulse to pass when the second clock pulse is present; and high voltage pulse generation means (41, 42) for generating a high voltage pulse in synchronism with the pulse output from the gate means.
Claim 10
Dependent Claim
107 words
An electroluminescent display device provided with a driver circuit for applying a driving voltage to the display device, the driver circuit comprising: first clock generator means (1) for generating a first clock pulse having a first frequency; second clock generator means (2) for generating a second clock pulse having a second frequency lower than the first frequency; gate means (3) for receiving the first and second clock pulses and allowing the first clock pulse to pass when the second clock pulse is present; and high voltage pulse generation means (41, 42) for generating a high voltage pulse in synchronism with the pulse output from the gate means.
Claim 11
Dependent Claim
22 words
A device as claimed in claim 7, wherein the high voltage pulse generation means is provided with a voltage multiplier circuit (43).
References Cited (Backward Citations)
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