Cholesteric liquid crystal display and driving method thereof

Abstract

This invention provides a cholesteric liquid crystal display (LCD) and its driving method, which reduces horizontal crosstalk. The cholesteric LCD includes a cholesteric liquid crystal panel and a controller. The cholesteric liquid crystal panel includes a plurality of pixel units. During a screen refresh cycle, the controller applies a plurality of data voltages arranged in a first polarity combination to the plurality of pixel units during a first scan period. The first polarity combination has different polarities. During the first scan period, the controller also applies a common-mode voltage having a DC voltage value to the plurality of pixel units.

Claims

1. A cholesterol-based liquid crystal display, comprising: A cholesterol-based liquid crystal panel, comprising multiple pixel units; The controller is coupled to the pixel units, wherein during a frame update cycle, the controller is configured to: apply a plurality of data voltages arranged in a first polarity combination to the pixel units during a first scan period, wherein the first polarity combination has different polarities; apply a common-mode voltage having a DC voltage value to the pixel units during the first scan period; apply the data voltages arranged in a second polarity combination to the pixel units during a second scan period, wherein the second polarity combination has different polarities and is opposite to the first polarity combination; and apply the common-mode voltage having the DC voltage value to the pixel units during the second scan period.

2. The cholesterol liquid crystal display as claimed in claim 1, wherein during the screen update cycle, the controller continues to execute the second scan period after executing the first scan period.

3. The cholesterol liquid crystal display as claimed in claim 1, wherein during the screen update cycle, after performing the first scan period, the controller continues to perform a swing period and then continues to perform the second scan period, wherein during the swing period, the controller applies the data voltages having the DC voltage value to the pixel units and applies the common-mode voltage having the DC voltage value to the pixel units.

4. The cholesterol liquid crystal display as claimed in claim 1, wherein the first polarity combination includes a plurality of first rows having a first polarity and a plurality of second rows having a second polarity, wherein the first rows are adjacent to each other and adjacent to the second rows that are adjacent to each other.

5. The cholesterol liquid crystal display as claimed in claim 1, wherein the first polarity combination includes a plurality of odd rows having a first polarity and a plurality of even rows having a second polarity.

6. The cholesterol liquid crystal display as claimed in claim 1, wherein the first polarity combination includes a plurality of first columns having a first polarity and a plurality of second columns having a second polarity, wherein the first columns are adjacent to each other and adjacent to the second columns that are adjacent to each other.

7. The cholesterol liquid crystal display as claimed in claim 1, wherein the first polarity combination comprises a plurality of odd columns having a first polarity and a plurality of even columns having a second polarity.

8. The cholesterol liquid crystal display as claimed in claim 1, wherein the first polarity combination includes a plurality of first elements having a first polarity and a plurality of second elements having a second polarity, wherein the first elements and the second elements are interleaved and arranged in a matrix.

9. The cholesterol liquid crystal display as claimed in claim 8, wherein each of the first elements comprises a plurality of first sub-elements and the first sub-elements are adjacent to each other, wherein each of the second elements comprises a plurality of second sub-elements and the second sub-elements are adjacent to each other.

10. The cholesterol liquid crystal display as claimed in claim 1, wherein each pixel unit comprises: A switching element having a first terminal that receives one of the corresponding data voltages; And a cholesterol liquid crystal pixel having a first end coupled to a second end of the switching element, the second end of the cholesterol liquid crystal pixel receiving the common-mode voltage.

11. A driving method for a cholesterol liquid crystal display, comprising: A controller applies multiple data voltages arranged in a first polarity combination to multiple pixel units during a first scan period of a screen update cycle, wherein the first polarity combination has different polarities; the controller also applies a common-mode voltage with a DC voltage value to the pixel units during the first scan period; the controller further applies the data voltages arranged in a second polarity combination to the pixel units during a second scan period of the screen update cycle, wherein the second polarity combination has different polarities and is opposite to the first polarity combination; and the controller also applies the common-mode voltage with the DC voltage value to the pixel units during the second scan period.

12. The driving method as described in claim 11, wherein during the screen update cycle, the controller continues to execute the second scan period after executing the first scan period.

13. The driving method as claimed in claim 11, wherein during the screen update cycle, after executing the first scan period, the controller continues to execute a swing period, and then continues to execute the second scan period, wherein the driving method further comprises: Through the controller, during the swing period, data voltages having the DC voltage value are applied to the pixel units; And through the controller, during the swing period, the common-mode voltage having the DC voltage value is applied to the pixel units.

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