Dynamic dimming LED backlight

• US 10,431,166 B2
• Filed: 08/07/2014
• Issued: 10/01/2019
• Est. Priority Date: 06/03/2009
• Status: Active Grant

• Current Assignee: Manufacturing Resources International, Inc.
• Original Assignee: Manufacturing Resources International, Inc.
• Inventors: Wasinger, Jerry, Dunn, William
• Primary Examiner(s): Nguyen, Kevin M
• Application Number:
  US14/453,966
• Publication Number:
  US 20140361969A1
• Time in Patent Office: 1,881 Days
• Field of Search: 345102
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/12 Frame memory handling
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

Disclosed herein is a system for controlling the interactions of light between adjacent subsections of a dynamic LED backlight. Preferred embodiments contain a dividing wall positioned between each adjacent subsection of the LED backlight. The dividing wall may be in contact with the LED backlight and extend away from the LED backlight. The dividing wall may prohibit light from a first subsection from entering an adjacent second subsection at its full luminance. The luminance for each adjacent subsection may be approximately half of the full luminance of each subsection, when measured at the location of the dividing wall.

Claims

1. An LED backlight assembly for a liquid crystal display (LCD), the LED backlight assembly comprising:

an LED backlight having a number of individually controllable subsections, wherein each subsection comprises a number of red light emitting LEDs, a number of green light emitting LEDs, and a number of blue light emitting LEDs, wherein simultaneous illumination of each of said number of red, green, and blue light emitting LEDs within a given subsection is configured to produce white light, and wherein each of said subsections comprises an equal number of red, green, and blue light emitting LEDs;

an unpenetrated dividing wall extending away from the LED backlight and separating adjacent subsections of the LED backlight;

a diffusing element placed in front of the LED backlight;

a gap located between the dividing wall and the diffusing element;

a histogram accumulator in electrical communication with the LED backlight;

a frame buffer; and

a digital signal processor in electrical communication with the LED backlight, wherein the digital signal processor is also in electrical communication with the LCD and is configured to send virtual backlight data to the LCD.

2. A system for controlling the interactions of light between adjacent subsections of a dynamic LED backlight, the system comprising:

a dividing wall positioned between adjacent subsections of the dynamic LED backlight, wherein the dividing wall extends below a diffusing element such that a gap is created between the diffusing element and an upper portion of the dividing wall;

wherein the dividing wall extends away from the LED backlight at a distance which creates a luminance overlap of adjacent subsections of 50% within the gap when measured at the dividing wall;

wherein said dynamic LED backlight comprises a number of color producing LEDs that are configured to be illuminated simultaneously to produce white light.

3. The system of claim 2 wherein:

the dividing wall is adapted to produce a Gaussian relationship for the interactions of light between adjacent subsections of the LED backlight.

4. The system of claim 2 further comprising:

a histogram accumulator in electrical communication with the LED backlight.

5. The system of claim 2 wherein:

the dividing wall extends less than three inches away from the LED backlight.

6. A system for controlling the interactions of light between adjacent subsections of a dynamic LED backlight, the system comprising:

a first subsection of the LED backlight;

a second subsection of the LED backlight positioned adjacent to the first subsection so as to create a border between the first and second LED subsections; and

a dividing wall positioned along the border and extending away from the LED backlight such that approximately one-half of the luminance of the first subsection and approximately one-half of the luminance of the second subsection is present at the dividing wall;

a gap located between the dividing wall and a diffusing element such that the border extends within the gap;

wherein each of said first subsection of the LED backlight and said second subsection of the LED backlight comprise a number of color producing LEDs that are configured to be illuminated simultaneously to produce white light;

wherein the first subsection and the second subsection are configured to be illuminated at approximately one-half of the full luminance when measured at the border and the remainder of the first subsection and the second subsection are configured to be illuminated at approximately full luminance when measured away from the border.

7. The system of claim 6, further comprising:

a histogram accumulator in electrical communication with the first and second subsections of the LED backlight.

8. The system of claim 6 wherein:

the full luminance of the first subsection is not permitted to cross the border into the second subsection.

9. The system of claim 6 wherein:

the luminance of the first subsection is gradually reduced as one moves from the border and into the second subsection.