Partially filterless and two-color subpixel liquid crystal display devices, mobile electronic devices including the same, and methods of operating the same

• US 8,836,624 B2
• Filed: 08/30/2007
• Issued: 09/16/2014
• Est. Priority Date: 02/15/2007
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Roberts, John, You, Chenhua
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US11/847,882
• Publication Number:
  US 20080198114A1
• Time in Patent Office: 2,574 Days
• Field of Search: 345 87-100, 345204-215
• US Class Current: 345/88
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

A liquid crystal display (LCD) device includes a pixel array including a plurality of pixels configured to display an image. The plurality of pixels respectively include a first subpixel configured to display first color image data, and a second subpixel configured to display second and third color image data. The LCD device may further include a backlight configured to emit the first, second, and/or third colors of light, and a backlight controller. The backlight controller may be configured to activate the backlight to emit the first and second colors of light at a same time to generate a first image component including a combination of the first color image data and the second color image data, and to separately emit the third color of light at a different time than the first and second colors of light to generate a second image component including the third color image data. The pixel array may be configured to display the first and second image components to provide a single image frame. Related devices and methods of operation are also discussed.

Claims

1. A liquid crystal display device, comprising:

a backlight configured to emit first and second colors of light; and

a backlight controller configured to activate the backlight to emit the first and second colors of light at a same time, wherein the backlight controller is configured to activate the backlight to emit the first color of light for a first duration of time, and wherein the backlight controller is configured to activate the backlight to emit the second color of light for a second duration of time different than the first duration of time, wherein the first and second durations of time overlap.

2. The device of claim 1, wherein the backlight controller is configured to activate the backlight to emit the first color of light for the first duration during a first portion of a first time period, and to emit the second color of light for the second duration during a second portion of the first time period, wherein the first and second portions of the first time period overlap and respectively include the same time.

3. The device of claim 2, wherein:

the backlight is further configured to emit a third color of light;

the backlight controller is configured to activate the backlight to emit the first and second colors of light at the same time during the first time period to generate a first image component including a combination of first color image data and second color image data; and

the backlight controller is configured to activate the backlight to separately emit the third color of light during a second time period that does not overlap with the first time period to generate a second image component including the third color image data.

4. The device of claim 3, wherein the respective durations of activation for the first and second colors of light within the first time period and the third light within the second time period are selected such that the first and second image components provide an image with a desired white point.

5. The device of claim 3, further comprising:

a pixel array including a plurality of pixels configured to display an image, wherein the plurality of pixels respectively comprise;

a first subpixel configured to display the first color image data; and

a second subpixel configured to display the second and third color image data,

wherein the pixel array is configured to sequentially display the first and second image components to provide a single image frame.

6. A liquid crystal display device, comprising:

a backlight configured to emit first, second, and third colors of light; and

a backlight controller configured to activate the backlight to emit the first and second colors of light at a same time to generate a first image component including a combination of first color image data and second color image data, and to separately emit the third color of light at a different time than the first and second colors of light to generate a second image component including the third color image data,

wherein the backlight controller is configured to activate the backlight to emit at least two of the first, second, and third colors of light for different durations.

7. The device of claim 6, further comprising:

a pixel array including a plurality of pixels configured to display an image, wherein the plurality of pixels respectively comprise;

a first subpixel configured to display the first color image data; and

a second subpixel configured to display the second and third color image data,

wherein the pixel array is configured to sequentially display the first and second image components to provide a single image frame.

8. The device of claim 7, wherein the first subpixel comprises a first liquid crystal shutter configured to be activated to an open state and a closed state and a first color filter configured to allow passage of a first color of light and prevent passage of a second color of light, and wherein the second subpixel comprises a second liquid crystal shutter configured to be activated to an open state and a closed state and a second color filter configured to allow passage of the second color of light and a third color of light and prevent passage of the first color of light.

9. The device of claim 8, wherein the first subpixel is configured to display the first and the third color image data, and wherein the first color filter is further configured to allow passage of the third color of light.

10. The device of claim 8, further comprising:

a shutter controller configured to selectively activate the first and second liquid crystal shutters when the backlight is activated to emit the first and second colors of light to display the first color image data and the second color image data at the same time to generate the first image component, and configured to selectively activate at least the second liquid crystal shutter when the backlight is activated to separately emit the third color of light to separately display the third color image data at the different time to generate the second image component.

11. The device of claim 6, wherein the backlight controller is configured to alternately activate the backlight to emit the first and second colors of light at the same time and activate the backlight to emit the third color of light at the different time than the first and second colors of light to sequentially display the first and second image components at a predetermined refresh rate.

12. The device of claim 11, wherein the predetermined refresh rate is based on a shutter rate of the first and/or second liquid crystal shutters.

13. The device of claim 6, wherein the backlight controller is configured to activate the backlight to emit the first and second colors of light during a first time period, and wherein the same time comprises at least a portion of the first time period.

14. The device of claim 13, wherein the backlight controller is configured to activate the backlight to emit the first color of light during a first portion of the first time period and emit the second color of light during a second portion of the first time period, wherein the first and second portions of the first time period have the different durations but respectively include the same time.

15. The device of claim 13, wherein the backlight controller is configured to activate the backlight to emit the third color of light during a second time period, and wherein a duration of the second time period is different than that of the first time period.

16. The device of claim 6, wherein the backlight comprises a solid state lighting panel comprising:

a first solid state lighting element configured to emit the first color of light;

a second solid state lighting element configured to emit the second color of light; and

a third solid state lighting element configured to emit the third color of light;

wherein the backlight controller is configured to activate the first and second solid state lighting elements at the same time to generate the first image component, and to activate the third solid state lighting element at the different time than the first and second solid state lighting elements to generate the second image component.

17. The device of claim 16, wherein the first, second, and/or third solid state lighting elements comprise a light-emitting diode (LED), an organic light-emitting diode (OLED), and/or a laser light source.

18. The device of claim 6, further comprising:

a battery electrically coupled to the pixel array and the backlight and configured to provide power thereto.

19. The device of claim 8, wherein a wavelength of the third color of light is greater than a wavelength of the second color of light but less than a wavelength of the first color of light.

20. The device of claim 19, wherein the first color of light comprises red light, wherein the second color of light comprises blue light, and wherein the third color of light comprises green light.