Surface illuminator and liquid crystal display having the same

• US 8,007,159 B2
• Filed: 04/28/2010
• Issued: 08/30/2011
• Est. Priority Date: 03/29/2005
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hamada, Tetsuya, Ohashi, Noriyuki
• Primary Examiner(s): Husar; Stephen F
• Assistant Examiner(s): Neils; Peggy A.
• Application Number:
  US12/768,774
• Publication Number:
  US 20100208164A1
• Time in Patent Office: 489 Days
• Field of Search: 362/610, 362/612, 362/613, 362/609, 362/615, 362/631, 362/632, 362/800, 362/231
• US Class Current: 362/612
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices

Abstract

The invention provides a surface illuminator capable of achieving high display quality by employing an array of discrete light sources constituted by a plurality of LEDs and a liquid crystal display having the same. The surface illuminator includes an LED module which is a plurality of LEDs alternately and discretely provided along a light entrance surface and a color irregularity correcting resistor which is connected in parallel with a predetermined LED at an end of the LED module and which provides a bypass for a current supplied to the LED.

Claims

1. A surface illuminator comprising:

a light exit region which spreads in the form of a plane and from which light exits;

a light guide region arranged to guide light to the light exit region;

a light entrance surface through which light enters the light guide region;

a reflective surface extending from an end of the light entrance surface and reflecting light in the light guide region; and

an LED module including a white LED set provided at only one end of the LED module and an LED set arranged next to the white LED set;

wherein

the white LED set includes only one or more white LEDs;

the LED set includes a plurality of LEDs that emit only light having a color that is not white; and

the one or more white LEDs and the plurality of LEDs are discretely provided along the light entrance surface.

2. A surface illuminator according to claim 1, further comprising:

a luminance irregularity correcting resistor connected in parallel with each of the one or more white LEDs; and

a switch arranged to switch the luminance irregularity correcting resistor.

3. A surface illuminator according to claim 1, wherein the one or more white LEDs are separately driven.

4. A surface illuminator according to claim 1, wherein the LEDs are arranged in the same order of colors from both ends of the reflective surface.

5. A surface illuminator according to claim 1, wherein optical sensors arranged to control luminance and chromaticity are provided at four corners and the center of a back side or front side of the light exit region.

6. A surface illuminator according to claim 1, wherein the LED module is provided on one side of the light entrance surface.

7. A surface illuminator according to claim 2, further comprising a housing defined by a sheet metal or mold including an adjusting hole arranged to allow the luminance irregularity correcting resistor to be adjusted from outside.

8. A liquid crystal display having a liquid crystal sealed between a pair of substrates provided opposite to each other, the display comprising a surface illuminator according to claim 1.

9. A surface illuminator according to claim 1, wherein the LED module includes another white LED set provided at another end of the LED module;

the another white LED set includes only one or more white LEDs; and

only the LED set is provided between the white LED set and the another white LED set.