EP0395387A2
Expired / Lapsed
EP
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Display drive circuit
Assignee: Citizen Watch Co Ltd
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Filing: 1990-04-25
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Granted: —
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Expires: 2010-04-25
Abstract
Abstract A display drive circuit including a pulse generator means, a variable voltage source circuit including a first voltage source line (VD t ) with a variable potential, a second voltage source line (VS t ) with a potential different from the first voltage source line by a constant value, having a voltage waveform, a variation period and a variation component the same as the first voltage source line, and varying in potential with a potential level not more than the lowest potential level of the first voltage source line, and other voltage source lines with constant potential levels between the potentials of the first and second voltage source lines; and an integrated circuit having an electronic switch which switches at a constant period the connection of the voltage source line so as to make a plurality of constant waveform voltage and outputting these to a plurality of output terminals at constant phase difference.
Inventors
- 👤 Shigeru Morokawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:41
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3696; G09G3/22; G09G3/30; G09G3/3674; G09G2310/00; G09G2310/02; G09G2310/0264; G09G2310/0289; G09G2330/00; G09G2330/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
A display drive circuit which comprises; a pulse generating means; a variable voltage source circuit comprising a first voltage source line (VD t ) with a variable potential, a second voltage source line (VS t ) with a potential different from said first voltage source line by a constant value, having the same potential waveform as the potential of said first voltage source line except said constant potential difference, and other plurality of constant potential voltage source lines with each constant voltage level of between the potentials of said first and second voltage source lines; and an integrated circuit having electronic switching means which switches at a constant period the connections of said respective voltage source lines so as to make a plurality of constant waveform voltages and outputting these to a plurality of output terminals at a constant phase difference.
Claim 2
Dependent Claim
141 words
A display drive circuit which comprises; a pulse generating means; a variable voltage source circuit comprising a first voltage source line (VD t ) with a variable potential, a second voltage source line (VS t ) with a potential different from said first voltage source line by a constant value, having the same potential waveform as the potential of said first voltage source line except said constant potential difference, and other plurality of constant potential voltage source lines with each constant voltage level of between the potentials of said first and second voltage source lines; and an integrated circuit having electronic switching means which switches at a constant period the connections of said respective voltage source lines so as to make a plurality of constant waveform voltages and outputting these to a plurality of output terminals at a constant phase difference.
Claim 3
Dependent Claim
140 words
An integrated circuit for a display drive circuit according to claim 1, wherein in said integrated circuit, said first voltage source line is connected to a positive electrode side of an integrated circuit substrate while said second voltage source line is connected to a negative electrode side; a complementary field effect transistor circuit is provided which comprises a P channel field effect transistor formed on said positive electrode substrate and an N channel field effect transistor formed on said negative electrode substrate; and said third voltage source line is connected to a source side of said P channel field effect transistor, while said fourth voltage source line is connected to a source side of said N channel field effect transistor, and an output terminal being connected to a common drain side of both the P-channel and N-channel field effect transistors.
Claim 4
Dependent Claim
143 words
A display drive circuit according to claim 1, wherein in said variable voltage source circuit, a voltage of a pulse supplied from said pulse generating means is clamped at a positive electrode side of a constant voltage source 348 and a negative electrode side of a constant voltage source 322 by clamping circuits comprising a capacitor and a switching device, respectively, and wherein a high voltage level side of the variable voltage source circuit is connected to said first voltage source line and a low voltage level side thereof is connected to said second voltage source line while a positive electrode side of said constant voltage source and a negative electrode side of said constant voltage source are connected to said third and fourth voltage source lines respectively, whereby an output voltage varying with period as a function of time can be obtained.
Claim 5
Dependent Claim
32 words
A display drive circuit according to claim 3, wherein said switching device used in said clamping circuit consists of any one of a diode, a field effect transistor, and a bipolar transistor.
Claim 6
Dependent Claim
28 words
A display drive circuit according to claim 3, wherein said switching device used in said clamping circuit is formed with a diode and a transistor arranged in parallelly.
References Cited (Backward Citations)
No citation records indexed.
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