Liquid crystal display
AssigneeChi Mei Optoelectronics Corp.
InventorsFu-Cheng Chen, Chia-Chi Wu
Life of this patent
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Abstract
An alternating electric field is applied across liquid crystal cells of pixels of an optically compensated birefringence mode liquid crystal display during a time period after power is provided to the display to cause the liquid crystal cells to change from a splay state to a bend state. The alternating electric field has a frequency that is less than 40 Hz. After the liquid crystal cells change to the bend state, a backlight module is turned on, and the pixels are controlled to show images with a refresh rate of greater than 40 Hz.
Claims25
A method for driving a liquid crystal display that includes a display panel having a common electrode, a plurality of pixel electrodes and an optically compensated birefringence (OCB) liquid crystal layer, the OCB liquid crystal layer positioned between the common electrode and the plurality of pixel electrodes, the driving method comprising:
- forming a transition electric field between the common electrode and the plurality of pixel electrodes when the liquid crystal display is turned on, and maintaining the transition electric field continuously for a specific time, wherein the frequency of the transition electric field is smaller than 40 Hz;
- and
- sending an image signal to the display panel after the specific time, and displaying an image on the liquid crystal display in response to the image signal.
A method for driving a liquid crystal display that includes a display panel having a common electrode, a plurality of pixel electrodes and an optically compensated birefringence (OCB) liquid crystal layer, the OCB liquid crystal layer positioned between the common electrode and the plurality of pixel electrodes, the driving method comprising:
- applying a common DC voltage to the common electrode or floating the common electrode, and applying a transition DC voltage to the plurality of pixel electrodes respectively when the liquid crystal display is turned on, to form a transition electric field between the common electrode and the plurality of pixel electrodes, and maintaining the transition electric field continuously for a specific time, wherein the common DC voltage and the transition DC voltage have different polarities;
- and
- sending an image signal to the display panel after the specific time, and displaying an image on the liquid crystal display in response to the image signal.
A method, comprising:
- applying an alternating electric field across liquid crystal cells of pixels of an optically compensated birefringence mode liquid crystal display after power is provided to the display to cause the liquid crystal cells to change from a splay orientation state to a bend orientation state, the alternating electric field having a frequency less than 40 Hz;
- and
- driving the pixels to show images with a refresh rate of greater than 40 Hz after the liquid crystal cells are in the bend orientation state.
An optically compensated birefringence (OCB) mode liquid crystal display, comprising:
- an array of pixels, each pixel comprising
- a common electrode,
- a pixel electrode, and
- a liquid crystal cell disposed between the common electrode and the pixel electrode;
- and
- a display controller to control voltage levels of the common electrode and the pixel electrodes to generate an alternating electric field across the liquid crystal cells after power is provided to the display to cause the liquid crystal cells to change from a splay state to a bend state, the alternating electric field having a frequency f less than 40 Hz, the display controller also controlling the array of pixels to show images with a refresh rate greater than 40 Hz after the liquid crystal cells change to the bend state.
Dependencies are inferred from the claim text.