CAPACITANCE VARIATION DETECTION CIRCUIT, AND DISPLAY DEVICE
First Claim
1. A capacitance variation detection circuit for detecting a variation in capacitance in a cell, comprising:
- a first variable capacitance portion connected to a voltage supply line;
a second variable capacitance portion connected in series with the first variable capacitance portion; and
a switching device connected to the second variable capacitance portion, the switching device being driven depending on a capacitance value of the first variable capacitance portion and a capacitance value of the second variable capacitance portion, to output an electrical signal corresponding to these capacitance values.
1 Assignment
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Accused Products
Abstract
A capacitance variation detection circuit is provided in which detection sensitivity to variations in the liquid crystal capacitance can be improved. A capacitance variation detection circuit (10) includes a first variable capacitance portion (CLC1) connected to the voltage supply line; a second variable capacitance portion (CLC2) connected in series with the first variable capacitance portion (CLC1); and a TFT (15) connected to the second variable capacitance portion (CLC2) to be driven depending on the capacitance value of the first variable capacitance (CLC1) and the capacitance value of the second variable capacitance (CLC2), to output an electrical signal corresponding to these capacitance values.
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Citations
5 Claims
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1. A capacitance variation detection circuit for detecting a variation in capacitance in a cell, comprising:
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a first variable capacitance portion connected to a voltage supply line; a second variable capacitance portion connected in series with the first variable capacitance portion; and a switching device connected to the second variable capacitance portion, the switching device being driven depending on a capacitance value of the first variable capacitance portion and a capacitance value of the second variable capacitance portion, to output an electrical signal corresponding to these capacitance values. - View Dependent Claims (2)
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3. A display device for detecting a contact location in a display screen based on a variation in capacitance between an electrode on a first substrate and an electrode on a second substrate, comprising:
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a plurality of pixel circuits; at least one capacitance variation detection circuit; and an active matrix substrate, wherein the capacitance variation detection circuit includes; a first variable capacitance portion connected to a voltage supply line; a second variable capacitance portion connected in series with the first variable capacitance portion; and a switching device connected to the second variable capacitance portion, the switching device being driven depending on a capacitance value of the first variable capacitance portion and a capacitance value of the second variable capacitance portion, to output an electrical signal corresponding to these capacitance values. - View Dependent Claims (4, 5)
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Specification