Liquid crystal display device, driving circuit, driving method, and electronic devices
First Claim
1. A liquid crystal display device, comprising:
- a scanning line which becomes an on-voltage at every predetermined interval;
a liquid crystal capacitor having a liquid crystal sandwiched between a counter electrode and a pixel electrode, the counter electrode being of a reference voltage that is unmodulated;
a data line which becomes a voltage corresponding to a density on the basis of the reference voltage of said counter electrode and to a writing polarity of said liquid crystal capacitor when said scanning line is the on-voltage;
a first switching element inserted between said data line and said pixel electrode, said first switching element being turned on when the on-voltage is applied to said scanning line, and being turned off when an off-voltage is applied;
a storage capacitor having one terminal connected to said pixel electrode and other terminal; and
a selector which, when the voltage of said data line corresponds to a positive-polarity writing during the period when the other terminal is the on-voltage, shifts the voltage of the other terminal to high after said scanning line turns off, and when the voltage of said data line corresponds to a negative-polarity writing during the period when the other terminal is the on-voltage, shifts the voltage of the other terminal to low after said scanning line turns off.
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Accused Products
Abstract
The voltage swing of a data signal, which is supplied to a data line, is maintained to be small, thereby reducing the power consumption. When a scanning signal supplied to a scanning line is set to an on-voltage, a data signal with a voltage, depending on the density and depending on the writing polarity, is applied to a data line. In this case, a TFT is turned on. Thus, a liquid crystal capacitor and storage capacitor store the charge corresponding to the voltage of the data signal. Then, the scanning signal is set to an off-voltage to turn the TFT off, and the voltage of the other terminal of the storage capacitor is raised from the low-level of capacitor voltage to the high-level, and the charge corresponding to the raised voltage amount is redistributed to the liquid crystal capacitor. Thus, the effective voltage value applied to the liquid crystal capacitor can correspond to the voltage swing of the data signal or more.
121 Citations
11 Claims
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1. A liquid crystal display device, comprising:
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a scanning line which becomes an on-voltage at every predetermined interval;
a liquid crystal capacitor having a liquid crystal sandwiched between a counter electrode and a pixel electrode, the counter electrode being of a reference voltage that is unmodulated;
a data line which becomes a voltage corresponding to a density on the basis of the reference voltage of said counter electrode and to a writing polarity of said liquid crystal capacitor when said scanning line is the on-voltage;
a first switching element inserted between said data line and said pixel electrode, said first switching element being turned on when the on-voltage is applied to said scanning line, and being turned off when an off-voltage is applied;
a storage capacitor having one terminal connected to said pixel electrode and other terminal; and
a selector which, when the voltage of said data line corresponds to a positive-polarity writing during the period when the other terminal is the on-voltage, shifts the voltage of the other terminal to high after said scanning line turns off, and when the voltage of said data line corresponds to a negative-polarity writing during the period when the other terminal is the on-voltage, shifts the voltage of the other terminal to low after said scanning line turns off. - View Dependent Claims (2, 3, 4, 9)
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5. A liquid crystal display device, comprising:
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a scanning line which becomes an on-voltage at every predetermined interval;
a liquid crystal capacitor having a liquid crystal sandwiched between a counter electrode and a pixel electrode;
a data line which becomes a voltage corresponding to a density on the basis of the voltage of said counter electrode and to a writing polarity of said liquid crystal capacitor when said scanning line is the on-voltage;
a first switching element inserted between said data line and said pixel electrode, said first switching element being turned on when the on-voltage is applied to said scanning line, and being turned off when an off-voltage is applied;
a storage capacitor having one terminal connected to said pixel electrode and other terminal, such that, when the voltage of said data line corresponds to a positive-polarity writing during the period when the other terminal is the on-voltage, the voltage of the other terminal is shifted to high after said scanning line turns off, and when the voltage of said data line corresponds to a negative-polarity writing during the period when the other terminal is the on-voltage, the voltage of the other terminal is shifted to low after said scanning line turns off;
a low-level capacitor line which is maintained at a predetermined first voltage;
a high-level capacitor line which is maintained at a second voltage that is higher than said first voltage; and
a selector which selects either one of said low-level capacitor line and said high-level capacitor line depending on the voltage of a selection signal line, and applies the voltage to the other terminal of said storage capacitor. - View Dependent Claims (6, 7, 8)
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10. A driving circuit for a liquid crystal display device, the liquid crystal display device including:
- a liquid crystal capacitor arranged at the intersection of a scanning line and a data line, and having a liquid crystal sandwiched between a counter electrode and pixel electrode, the counter electrode being of a reference voltage that is unmodulated;
a first switching element inserted between said data line and said pixel electrode, said first switching element being turned on when the on-voltage is applied to said scanning line, and being turned off when an off-voltage is applied; and
a capacitor of which one terminal is connected to said pixel electrode, the driving circuit comprising;a scanning line driving circuit which turns said scanning line an on-voltage at every predetermined interval;
a data line driving circuit which turns the voltage of said data line to a voltage corresponding to a density on the basis of the reference voltage of said counter electrode and to a writing polarity of said liquid crystal capacitor when said scanning line is on-voltage; and
a storage capacitor driving circuit, such that, when the voltage of said data line corresponds to a positive-polarity writing during the period when said scanning line is the on-voltage, the voltage of the other terminal of said storage capacitor is shifted to high after said scanning line turns off, and when the voltage of said data line corresponds to a negative-polarity writing during the period when said scanning line is on-voltage, the voltage of the other terminal of said storage capacitor is shifted to low after said scanning line turns off the storage capacitor driving circuit including;
a low-level capacitor line which is maintained at a predetermined first voltage;
a high-level capacitor line which is maintained at a second voltage that is higher than said first voltage; and
a selector which selects either one of said low-level capacitor line and said high-level capacitor line depending on the voltage of a selection signal line, and applies the voltage to the other terminal of said storage capacitor.
- a liquid crystal capacitor arranged at the intersection of a scanning line and a data line, and having a liquid crystal sandwiched between a counter electrode and pixel electrode, the counter electrode being of a reference voltage that is unmodulated;
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11. A driving method for a liquid crystal display device, the liquid crystal display device including:
- a liquid crystal capacitor arranged at the intersection of a scanning line and a data line, and having a liquid crystal sandwiched between a counter electrode and pixel electrode, the counter electrode being of a reference voltage that is unmodulated;
a first switching element inserted between said data line and said pixel electrode, said first switching element being turned on when the on-voltage is applied to said scanning line, and being turned off when an off-voltage is applied; and
a capacitor having one terminal connected to said pixel electrode and other terminal, the driving method comprising;turning a scanning line an on-voltage at every predetermined interval;
turning a voltage of said data line to a voltage difference corresponding to a density on the basis of the reference voltage of said counter electrode and to a writing polarity of said liquid crystal capacitor when said scanning line is the on-voltage;
shifting the voltage of the other terminal of said storage capacitor to high after said scanning line turns off when said data line corresponds to a positive-polarity writing during the period when said scanning line is the on-voltage, the high voltage being maintained by a high-level capacitor line; and
shifting the voltage of the other terminal of said storage capacitor to low after said scanning line turns off when said data line corresponds to a negative-polarity writing during the period when said scanning line is the on-voltage, the low voltage being maintained by a low-level capacitor line, either one of said low-level capacitor line and said high-level capacitor line being selected depending on the voltage of a selection signal line, and either one of the high or the low voltage being applied to the other terminal of said storage capacitor.
- a liquid crystal capacitor arranged at the intersection of a scanning line and a data line, and having a liquid crystal sandwiched between a counter electrode and pixel electrode, the counter electrode being of a reference voltage that is unmodulated;
Specification