Area active backlight with steerable light source

• US 7,982,822 B2
• Filed: 01/28/2009
• Issued: 07/19/2011
• Est. Priority Date: 01/28/2009
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Feng, Xiao-fan
• Primary Examiner(s): Ullah; Akm E
• Application Number:
  US12/322,115
• Publication Number:
  US 20100188610A1
• Time in Patent Office: 902 Days
• Field of Search: 349 62- 69, 349/139, 349/141, 349/15, 362/615, 362/612, 362/607, 345/84, 345/86, 345/102, 385/129, 385/140, 385/147
• US Class Current: 349/62
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 2201/06 integrated waveguide
• CPC Class Codes: G02F 2203/026 attenuated or frustrated internal reflection
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines

Abstract

A liquid crystal display includes a backlight. The backlight includes a plurality of waveguides to selectively direct light. A set of selection elements in combination with the backlight selectively direct light to the front of the display.

Claims

1. A display comprising:

(a) a liquid crystal layer;

(b) a backlight that provides light to said liquid crystal layer;

(c) said liquid crystal layer selectively modifying the transmission of light from said backlight to the front of said display;

(d) said backlight includes a plurality of spaced apart light waveguides arranged in a one-dimensional parallel array extending from one side to the other side of said display;

(e) said backlight includes at least one light source associated with each of said waveguides;

(f) said display includes a plurality of selection elements associated with each of said waveguides such that selective activation of one of said selection elements causes light to pass through said associated waveguide that is directed direct light toward said liquid crystal layer while light does not similarly pass through said associated waveguide where one of said selection element is not selected;

(g) each of said waveguides are provided with light in a sequential manner while a plurality of associated selection elements for each of said waveguides are selected so that light is selectively emitted from each of said respective waveguide.

2. The display of claim 1 wherein regions of an image to be displayed that is determined not to have motion have a slower rate of providing light to said waveguides than regions of said image to be display that is determined to have motion.