EP0428250A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Driver circuit for a display panel
Assignee: Sharp Corp
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Filing: 1990-08-31
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Granted: —
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Expires: 2010-08-31
Abstract
Abstract A common driver circuit for driving a load heavy in a capacitive property such as a common electrode or the like of a liquid crystal panel is composed of the simple circuit construction provided with each circuit of the voltage follower, the low-pass filter, the feedback, the control so that the variation in the direction current component which gives bad influences in the processing of the signals of this type of circuit is restrained to improve the reliability, and the direct current is not required to be cut to eliminate the direct current cutting capacitor of the large capacity.
Inventors
- 👤 Takeshi Shibata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 19:15
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G3/3655
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
A common driver circuit for liquid crystal panel driving use, comprising an output circuit composed of a buffer amplifier capable of sufficiently driving the capacitive load or of a voltage follower, a means for feeding common signals and common biases to the above described output circuit, a bias setting means for setting the above described common bias, a control means which detects the direct current level of the above described output circuits, so that the common bias set by the above described bias setting means may be normally retained through the use of the detection output.
Claim 2
Dependent Claim
96 words
A common driver circuit for liquid crystal panel driving use, comprising an output circuit composed of a buffer amplifier capable of sufficiently driving the capacitive load or of a voltage follower, a means for feeding common signals and common biases to the above described output circuit, a bias setting means for setting the above described common bias, a control means which detects the direct current level of the above described output circuits, so that the common bias set by the above described bias setting means may be normally retained through the use of the detection output.
Claim 3
Dependent Claim
117 words
A driver circuit for driving a capacitive load in accordance with supplied drive signals, for example a common driver circuit for driving a liquid crystal display panel, the circuit comprising an output circuit (18; 54) adapted for driving the capacitive load, means (11) for feeding the supplied drive signals to said output circuit, means (14) for setting a desired DC bias level for the drive signals, means (R₅, C₁; R₁₇, C₁₂) for detecting the DC level of the signal from the output circuit, and control means (12) for controlling the feeding means so as to adjust the said DC bias to said desired level in response to the outputs of said setting means and said detecting means.
Claim 4
Dependent Claim
117 words
A driver circuit for driving a capacitive load in accordance with supplied drive signals, for example a common driver circuit for driving a liquid crystal display panel, the circuit comprising an output circuit (18; 54) adapted for driving the capacitive load, means (11) for feeding the supplied drive signals to said output circuit, means (14) for setting a desired DC bias level for the drive signals, means (R₅, C₁; R₁₇, C₁₂) for detecting the DC level of the signal from the output circuit, and control means (12) for controlling the feeding means so as to adjust the said DC bias to said desired level in response to the outputs of said setting means and said detecting means.
Claim 5
Dependent Claim
19 words
A driver circuit according to claim 2 wherein said detecting means (R₅, C₁; R₁₇, C₁₂) comprises a low-pass filter.
Claim 6
Dependent Claim
45 words
A driver circuit according to claim 2 or claim 3 wherein said feeding means comprises an operational amplifier (19; 52) receiving at a first input terminal thereof the supplied drive signals and at a second terminal thereof a controlled signal from said control means (12).
Claim 7
Dependent Claim
50 words
A driver circuit according to any preceding claim wherein said output circuit (18; 54) is a voltage follower circuit comprising an operational amplifier (15) and a buffer amplifier means (Q₁, Q₂; Q₁₁, Q₁₂) the output of said operational amplifier means being coupled to said detecting means (R₅, C₁; R1₁₇, C₁₂).
Claim 8
Dependent Claim
40 words
A driver circuit according to any preceding claim, wherein said control means includes a first controller (14) for DC bias level setting, and a second controller (13) for adjusting the amplitude of the control signal supplied to the feeding means.
References Cited (Backward Citations)
No citation records indexed.
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