Field sequential liquid crystal display and driving method thereof

• US 8,022,924 B2
• Filed: 12/03/2007
• Issued: 09/20/2011
• Est. Priority Date: 12/29/2006
• Status: Expired due to Fees

• Current Assignee: Wintek Corporation
• Original Assignee: Wintek Corporation
• Inventors: Lo, Shin-Tai, Wu, Fa-Chen, Weng, Ruey-Shing
• Primary Examiner(s): Wang; Quan-Zhen
• Assistant Examiner(s): Ma; Calvin
• Application Number:
  US11/987,585
• Publication Number:
  US 20080158207A1
• Time in Patent Office: 1,387 Days
• Field of Search: 345/88, 345/102, 345/207, 349/61
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0237 Switching ON and OFF the backlight within one frame
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A field sequential driving method includes the following steps. First, a liquid crystal display (LCD) including a display unit and a backlight unit is provided. The display unit includes several pixel units. Next, a white light source of the backlight unit is enabled during a first sub-frame period of a frame period of the LCD. Then, red and blue sub-pixel data are provided to drive a first sub-pixel and a second sub-pixel in the pixel unit during the first sub-frame period. Next, a green light source of the backlight unit is enabled during a second sub-frame period of the frame period. Thereafter, green sub-pixel data is provided to drive a third sub-pixel of the pixel unit during the second sub-frame period.

Claims

1. A field sequential liquid crystal display (LCD), comprising:

a control unit for receiving pixel data, which comprises red sub-pixel data, green sub-pixel data, blue sub-pixel data and black sub-pixel data, wherein the control unit outputs the red and blue sub-pixel data during a first sub-frame period of a frame period and outputs the green sub-pixel data during a second sub-frame period of the frame period;

a backlight unit comprising a white light emitting diode (LED) and a green LED, which are driven by the control unit to output white light and green light during the first and second sub-frame periods, respectively, wherein the white and green LEDs are disabled during the second and first sub-frame periods, respectively; and

a display unit comprising a plurality of pixel units, each of which comprises;

a first sub-pixel, which comprises a red color filter and displays a red data frame according to the red sub-pixel data and the white light during the first sub-frame period;

a second sub-pixel, which comprises a blue color filter and displays a blue data frame according to the blue sub-pixel data and the white light during the first sub-frame period; and

a third sub-pixel, which comprises a green color filter and displays a green data frame according to the green sub-pixel data and the green light during the second sub-frame period;

wherein the control unit provides the black sub-pixel data to the first and second sub-pixels during the second sub-frame period, and provides the black sub-pixel data to the third sub-pixel during the first sub-frame period;

during the first sub-frame period, the control unit concurrently outputs the red, the blue and the black sub-pixel data to the first, the second and the third sub-pixels, respectively; and

during the second sub-frame period, the control unit concurrently outputs the black, the black and the green sub-pixel data to the first, the second and the third sub-pixels, respectively.

2. A field sequential liquid crystal display (LCD), comprising:

a control unit for receiving pixel data, which comprises red sub-pixel data, green sub-pixel data, blue sub-pixel data and black sub-pixel data, outputting the red and blue sub-pixel data during a first sub-frame period of a frame period, and outputting the green sub-pixel data during a second sub-frame period of the frame period;

a backlight unit comprising a white LED and a green LED, which are driven by the control unit to output white light and green light during the first and second sub-frame periods, respectively, wherein the white and green LEDs are disabled during the second and first sub-frame periods, respectively; and

a display unit comprising a plurality of pixel units, each of which comprises;

a first sub-pixel, which comprises a red color filter and displays a red data frame according to the red sub-pixel data and the white light during the first sub-frame period;

a second sub-pixel, which comprises a blue color filter and displays a blue data frame according to the blue sub-pixel data and the white light during the first sub-frame period; and

a third sub-pixel for displaying a green data frame according to the green sub-pixel data and the green light during the second sub-frame period;

wherein the control unit provides the black sub-pixel data to the first and second sub-pixels during the second sub-frame period,

during the first sub-frame period, the control unit concurrently outputs the red, the blue, and the black sub-pixel data to the first, the second and the third sub-pixels, respectively; and

during the second sub-frame period, the control unit concurrently outputs the black, the black and the green sub-pixel data to the first, the second and the third sub-pixels, respectively.

3. The LCD according to claim 2, wherein the control unit provides the black sub-pixel data to the third sub-pixel during the first sub-frame period.

4. The LCD according to claim 2, wherein the pixel data further comprises white sub-pixel data, and the control unit outputs the white sub-pixel data to the third sub-pixel during the first sub-frame period.

5. The LCD according to claim 4, wherein the third sub-pixel further receives the white sub-pixel data during the first sub-frame period and outputs a white data frame according to the white sub-pixel data and the white light.

6. The LCD according to claim 2, wherein the third sub-pixel comprises a white filter.

7. A field sequential driving method applicable to a liquid crystal display (LCD) having a display unit and a backlight unit, the display unit having a plurality of pixel units, the method comprising the steps of:

enabling a white LED of the backlight unit to output white light during a first sub-frame period of a frame period;

providing red sub-pixel data to drive a first sub-pixel of the pixel units during the first sub-frame period, the first sub-pixel displaying a red data frame according to the red sub-pixel data and the white light;

providing blue sub-pixel data to drive a second sub-pixel of the pixel units during the first sub-frame period, the second sub-pixel displaying a blue data frame according to the blue sub-pixel data and the white light;

enabling a green LED of the backlight unit to output green light during a second sub-frame period of the frame period; and

providing green sub-pixel data to drive a third sub-pixel of the pixel units during the second sub-frame period, the third sub-pixel displaying a green data frame according to the green sub-pixel data and the green light;

wherein;

during the first sub-frame period, the control unit concurrently outputs the red, the blue, and the white sub-pixel data to the first, the second and the third sub-pixels, respectively; and

during the second sub-frame period, the control unit concurrently outputs the black, the black and the green sub-pixel data to the first, the second and the third sub-pixels, respectively.

8. The method according to claim 7, further comprising the step of:

providing black sub-pixel data to drive the first and second sub-pixels during the second sub-frame period.

9. The method according to claim 7, further comprising the step of:

providing the black sub-pixel data to drive the third sub-pixel during the first sub-frame period.

10. The method according to claim 7, further comprising the step of:

providing white sub-pixel data to drive the third sub-pixel during the first sub-frame period, the third sub-pixel outputting a white data frame according to the white sub-pixel data and the white light.