Light source system for a color flat panel display

• US 8,111,210 B2
• Filed: 01/13/2009
• Issued: 02/07/2012
• Est. Priority Date: 05/15/2001
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Lowles, Robert J., Robinson, James A.
• Primary Examiner(s): Dharia, Prabodh M
• Application Number:
  US12/352,710
• Publication Number:
  US 20090122004A1
• Time in Patent Office: 1,120 Days
• Field of Search: 345/1.1, 345 4- 6, 345 87-102, 345/211, 345/690, 345/691, 345419-424, 345471-4722, 345/431, 345 56- 59, 345/74.1, 345/75.1, 345/75.2, 455/556.1, 455/556.2, 455/574, 349/78.5
• US Class Current: 345/56
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2340/14 Solving problems related to the presentation of information to be displayed
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127

Abstract

A system for operating a color flat panel display (FPD) is provided that includes a color FPD, a light source, and a display processing device. The color FPD has an adjustable color depth and is configured to reflect ambient light. The light source transmits light through the bottom surface of the color FPD. The display processing device is coupled to the color FPD and decreases the color depth of the color FPD when the light source is activated and increases the color depth of the color FPD when the light source is turned off.

Claims

1. A system for operating a color flat panel display, comprising:

the color flat panel display having a bottom surface and having a reflector to reflect ambient light for viewing of the color flat panel display, the color flat panel display having an adjustable color depth;

a light source for emitting light through the bottom surface of the color flat panel display;

a user interface coupled to the light source for activating the light source and for receiving a user input to set the adjustable color depth; and

a display processing device coupled to the color flat panel display for automatically decreasing the adjustable color depth of the color display when the light source is activated and automatically increasing the adjustable color depth of the color display when the light source is deactivated;

wherein the color flat panel display is configured to allow more reflection of ambient light than transmission of light emitted from the light source.

2. The system of claim 1, wherein the adjustable color depth is a set of eight colors when the light source is activated.

3. The system of claim 1, wherein the user interface is further coupled to the display processing device and includes a low-light mode input to activate the light source and a further input to adjust the adjustable color depth of the color.

4. The system of claim 1, wherein the user interface is further coupled to the display processing device and includes a reflective mode input to deactivate the light source and a further input to adjust the adjustable color depth of the color flat panel display.

5. The system of claim 3, wherein the low-light mode input also increases the font size of the color flat panel display from a first font size to a second font size.

6. The system of claim 4, wherein the reflective mode input also decreases the font size of the color flat panel display from the second font size to the first font size.

7. The system of claim 5, wherein a second occurrence of the low-light mode input increases the font size of the color flat panel display from the second font size to a third font size.

8. The system of claim 1, wherein the display processing device is one of a microprocessor, a display controller, and a combination the microprocessor and the display controller.

9. The system of claim 1, wherein the color flat panel display is one of a liquid crystal display and a digital paper display.

10. A system for operating a color flat panel display, comprising:

the color flat panel display having a bottom surface and having a reflector to reflect ambient light for viewing of the color flat panel display, where the color flat panel display has an adjustable color depth;

a light source for emitting light through the bottom surface of the color flat panel display;

a user interface coupled to the light source for activating the light source and for receiving a user input to set the adjustable color depth; and

a display processing device coupled to the color flat panel display for automatically decreasing the adjustable color depth of the color display when the light source is activated and automatically increasing the adjustable color depth of the color display when the light source is deactivated.

11. The system of claim 10, wherein the adjustable color depth is a set of eight colors when the light source is activated.

12. The system of claim 10, wherein the user interface is further coupled to the display processing device and includes a low-light mode input to activate the light source and a further input to adjust the adjustable color depth of the color.

13. The system of claim 10, wherein the user interface is further coupled to the display processing device includes a reflective mode input to deactivate the light source and a further input to adjust the adjustable color depth of the color flat panel display.

14. The system of claim 12, wherein the low-light mode input also increases the font size of the color flat panel display from a first font size to a second font size.

15. The system of claim 13, wherein the reflective mode input also decreases the font size of the color flat panel display from the second font size to the first font size.

16. The system of claim 14, wherein a second occurrence of the low-light mode input increases the font size of the color flat panel display from the second font size to a third font size.

17. The system of claim 10, wherein the display processing device is one of a microprocessor, a display controller, and a combination the microprocessor and the display controller.

18. The system of claim 10, wherein the color flat panel display is one of a liquid crystal display and a digital paper display.

19. A color liquid crystal display (LCD) module, comprising:

an upper transparent plate having a front polarizer and having a top surface for viewing;

a lower transparent plate having a bottom surface and a rear polarizer;

a liquid crystal layer between the upper transparent plate and the lower transparent plate for adjusting color depth of light passing through the liquid crystal layer;

a color filter for filtering light;

an electroluminescent (EL) light source for emitting light through the bottom surface of the lower transparent plate; and

a reflector for reflecting ambient light back through the liquid crystal layer and for passing light from the EL light source;

wherein the liquid crystal decreases the color depth when the EL light source is activated and increases the color depth when the light source is deactivated

wherein a first font size displayed by the LCD is increased to a second font size while the EL light source is activated.

20. The color LCD module of claim 19, wherein the reflector is configured to allow for more reflection of ambient light than the transmission of emitted light from the EL light source.

21. The color LCD module of claim 19, wherein the upper and lower transparent plates are one of glass, plastic, and a combination of glass and plastic.

22. A method of operating a color flat panel display, the color flat panel display having a color depth, having a light source and a reflector, comprising:

receiving input for controlling the light source to one of activate and deactivate;

controlling the light source, in response to the input, to one of activate and deactivate; and

decreasing the color depth of the color flat panel display when the light source is activated and increasing the color depth of the color panel display when the light source is deactivated;

wherein the color depth is adjusted to a predetermined setting in response to an input.

23. The method of claim 22, wherein the reflector is configured to allow for more reflection of ambient light than transmission of emitted light from the light source.

24. The method of claim 22, further comprising increasing a font size of content being displayed by the color flat panel display when the light source is activated.

25. The method of claim 24, further comprising:

monitoring for a second occurrence of the input and, in response to receiving a second occurrence of the input, further increasing the font size.

26. The method of claim 22, wherein the color depth is a set of eight colors when the light source is activated.

27. A method of operating a color liquid crystal display (LCD) module, the LCD module comprising:

an upper transparent plate having a front polarizer and having a top surface for viewing;

a lower transparent plate having a bottom surface and a rear polarizer;

a liquid crystal layer between the upper transparent plate and the lower transparent plate for adjusting color depth of light passing through the liquid crystal layer;

a color filter for filtering light;

an electroluminescent (EL) light source for emitting light through the bottom surface of the lower transparent plate; and

a reflector for reflecting ambient light back through the liquid crystal layer 2nd for passing light from the EL light source;

the method comprising;

decreasing the color depth when the EL light source is activated and increasing the color depth when the EL light source is deactivated;

wherein a first font size displayed by the LCD is increased to a second font size while the EL light source is activated.

28. The method of claim 27, wherein the reflector is configured to allow for more reflection of ambient light than the transmission of emitted light from the EL light.

29. The method of claim 27, wherein the upper and lower transparent plates are one of glass, plastic, and a combination of glass and plastic.

30. The method of claim 27, wherein the color depth is a set of eight colors when the EL light source is activated.