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US 2024/0404486 A1Published application
Liquid crystal display device and method of driving the same
AssigneeSharp Display Technology Corporation
InventorsKAORU YAMAMOTO, KOHHEI TANAKA, Keiichi YAMAMOTO
Life of this patent
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Abstract
In a first transition period during which an operation mode transitions from a normal mode to a low power consumption mode, a VCOM generation unit in a power source IC changes a potential of a common electrode drive voltage VCOM from a potential of a first level (for example, 5 V) to a potential of a second level (for example, 12 V) so that a leakage current flowing through a pixel transistor is not generated during a pause period, a gate driver changes a potential of each gate bus line to 0 V, and a source driver changes a potential of each source bus line to 0 V.
Claims16
A liquid crystal display device capable of switching an operation mode between a normal mode and a low power consumption mode, the liquid crystal display device comprising:
- a plurality of scanning signal lines;
- a plurality of video signal lines intersecting the plurality of scanning signal lines;
- a plurality of pixel forming portions each connected to one of the plurality of scanning signal lines and one of the plurality of video signal lines;
- a scanning signal line drive circuit configured to drive the plurality of scanning signal lines;
- a video signal line drive circuit configured to drive the plurality of video signal lines;
- a common electrode provided in common to the plurality of pixel forming portions;
- and
- a power source circuit configured to generate a first power source voltage to be supplied to the common electrode,
- wherein each of the plurality of pixel forming portions includes
- a pixel electrode,
- a pixel transistor including a control terminal connected to one of the plurality of scanning signal lines, a first conduction terminal connected to one of the plurality of video signal lines, and a second conduction terminal connected to the pixel electrode,
- the common electrode, and
- a liquid crystal capacitance formed by the pixel electrode and the common electrode,
- a period during which the operation mode is set to be the low power consumption mode includes a rewrite period during which a video signal is written to the liquid crystal capacitance and a pause period during which a video signal is not written to the liquid crystal capacitance,
- in a first transition period during which the operation mode transitions from the normal mode to the low power consumption mode,
- the power source circuit changes a potential of the first power source voltage from a potential of a first level to a potential of a second level so that a leakage current flowing through the pixel transistor is not generated during the pause period,
- the scanning signal line drive circuit changes potentials of the plurality of scanning signal lines from a potential of a predetermined off level to 0 V, and
- the video signal line drive circuit changes potentials of the plurality of video signal lines to 0 V, and
- in a second transition period during which the operation mode transitions from the low power consumption mode to the normal mode,
- the scanning signal line drive circuit changes the potentials of the plurality of scanning signal lines from 0 V to the potential of the predetermined off level, and
- the power source circuit changes the potential of the first power source voltage from the potential of the second level to the potential of the first level.
18 more elements
A method of driving a liquid crystal display device capable of switching an operation mode between a normal mode and a low power consumption mode,
- the liquid crystal display device including
- a plurality of scanning signal lines,
- a plurality of video signal lines intersecting the plurality of scanning signal lines,
- a plurality of pixel forming portions each connected to one of the plurality of scanning signal lines and one of the plurality of video signal lines,
- a scanning signal line drive circuit configured to drive the plurality of scanning signal lines,
- a video signal line drive circuit configured to drive the plurality of video signal lines,
- a common electrode provided in common to the plurality of pixel forming portions, and
- a power source circuit configured to generate a first power source voltage to be supplied to the common electrode,
- each of the plurality of pixel forming portions including
- a pixel electrode,
- a pixel transistor including a control terminal connected to one of the plurality of scanning signal lines, a first conduction terminal connected to one of the plurality of video signal lines, and a second conduction terminal connected to the pixel electrode,
- the common electrode, and
- a liquid crystal capacitance formed by the pixel electrode and the common electrode,
- a period during which the operation mode is set to be the low power consumption mode including a rewrite period during which a video signal is written to the liquid crystal capacitance and a pause period during which a video signal is not written to the liquid crystal capacitance,
- the driving method comprising:
- causing the operation mode to transition from the normal mode to the low power consumption mode, and
- causing the operation mode to transition from the low power consumption mode to the normal mode,
- wherein the causing of the operation mode to transition from the normal mode to the low power consumption mode includes
- causing the video signal line drive circuit to change potentials of the plurality of video signal lines to 0 V,
- causing the power source circuit to change the potential of the first power source voltage from a potential of a first level to a potential of a second level so that a leakage current flowing through the pixel transistor is not generated during the pause period, and
- causing the scanning signal line drive circuit to change potentials of the plurality of scanning signal lines from a potential of a predetermined off level to 0 V, and
- the causing of the operation mode to transition from the low power consumption mode to the normal mode includes
- causing the power source circuit to change the potential of the first power source voltage from the potential of the second level to the potential of the first level, and
- causing the scanning signal line drive circuit to change the potentials of the plurality of scanning signal lines from 0 V to the potential of the predetermined off level.
21 more elements
Dependencies are inferred from the claim text.