Lighting device, display device, and television device

Patent metadata

Field	Value
Publication number	US-2020241195-A1
Application number	US-201615762462-A
Country	US
Kind code	A1
Filing date	Sep 23, 2016
Priority date	Sep 24, 2015
Publication date	Jul 30, 2020
Grant date	—

Abstract

A backlight unit includes LEDs, a light guide plate, a wavelength converter, and an LED controller. The LEDs include end-side LEDs arranged at ends in the direction of arrangement and a center LED arranged at the center in the direction of arrangement. The light guide plate includes a light entering end surface and a light exiting plate surface. The light entering end surface extends along the direction of arrangement. The wavelength converter extends along the direction of arrangement and is interposed among the LEDs and the light entering end surface. The wavelength converter includes a phosphor configured to wavelength-convert the light from the LEDs. The LED controller is configured to control the amount of light emitted by each LED per unit time such that the amount of light emitted by at least one of the end-side LEDs than the amount of light emitted by the center LED.

First claim

1 . A lighting device comprising:
a plurality of light sources arranged in line including a plurality of end-side light sources arranged at ends in a direction of arrangement of the light sources and a center light source arranged at a center in the direction of arrangement; a light guide plate including:
a light entering end surface through which light from the light sources enters, the light entering end surface being at least a section of an outer peripheral end surface of the light guide plate extending along the direction of arrangement; and
a light exiting plate surface through which the light exits, the light exiting plate surface being one of plate surfaces of the light guide plate;
at least one wavelength converter extending along the direction of arrangement and interposed among the light sources and the light entering end surface, the at least one wavelength converter including a phosphor configured to wavelength-convert the light from the light sources; and a light source controller configured to control an amount of light emitted by each of the light sources per unit time such that the amount of light emitted by at least one of the end-side light sources is less than the amount of light emitted by the center light source.

2 . The lighting device according to claim 1 , wherein
the at least one wavelength converter is configured such that one of end portions in a length direction of the at least one wavelength converter is defined as a scaling member disposed end portion in which a sealing member is disposed and the other end portion is defined as a sealing member non-disposed end portion not provided with the sealing member, and the light source controller is configured to control the amount such that the amount of light emitted by one of the end-side light sources facing the sealing member disposed end portion of the at least one wavelength converter is less than the amount of light emitted by the other one of the end-side light sources facing the sealing member non-disposed end portion of the at least one wavelength converter.

3 . The lighting device according to claim 1 , wherein
the at least one wavelength converter includes a plurality of wavelength converters arranged in line along the direction of arrangement, and the light source controller is configured to control the amount such that the amount of light emitted by each of the end-side light sources facing a corresponding one of not-adjacent end portions of the wavelength converters than the amount of light emitted by the center light source.

4 . The lighting device according to claim 1 , wherein the light source controller is configured to supply a pulse signal to the light sources and to adjust a time ratio between a turn-on period and a turn-off period of the light sources to control the amount of light emitted per unit time.

5 . The lighting device according to claim 1 , wherein the light source controller is configured to drive the light sources with constant current and differentiate a value of current supplied to the light sources to control the amount of light emitted per unit time.

6 . A lighting device comprising:
a wavelength conversion member including:
a first wavelength converter containing a first phosphor to release secondary light when excited by primary light in a predetermined wavelength region, the secondary light being in another wavelength region different from the predetermined wavelength region;
a housing having an elongated shape and light transmissivity, the hosing holding the first wavelength converter to surround the first wavelength converter; and
a non-wavelength-converter portion formed by an end portion of the housing in a longitudinal direction thereof;
a light source line including a line of light sources arranged to face the wavelength conversion member, the light sources including a reference color light source and a mixed color light source, the reference color light source facing the first wavelength converter to emit the primary light toward the first wavelength converter, the mixed color light source facing the non-wavelength-converter portion to emit primary light and complementary color light in a complementary color to a reference color of the primary light toward the non-wavelength-converter portion; and a light guide plate including:
a light entering surface through which the light emitted by each light source in the light source line enters via the wavelength conversion member disposed in a clearance between the light source line and the light entering surface; and
a light exiting surface through which the light entering through the light entering surface exits.

7 . The lighting device according to claim 6 , wherein
the first wavelength converter of the wavelength conversion member is configured such that the first phosphor is dispersed in transparent resin, the housing of the wavelength conversion member is formed of a cylindrical body sealed at both ends thereof, and the non-wavelength-converter portion of the wavelength conversion member is formed by a sealed end portion of the cylindrical body.

8 . The lighting device according to claim 6 , wherein the mixed color light source includes a section that does not face the non-wavelength-converter portion but directly faces the light entering surface such that some rays of the light emitted by the mixed color light source directly enter the light entering surface.

9 . The lighting device according to claim 6 , wherein the mixed color light source includes:
a primary light source configured to emit the primary light; and a second wavelength converter formed to cover a light emitting portion of the primary light source and to pass the primary light therethrough, the second wavelength converter containing a second phosphor to release the secondary light when excited by some rays of the primary light.

10 . A display device comprising:
the lighting device according to claim 1 ; and a display panel configured to display an image by means of light emitted by the lighting device.

11 . A television device comprising the display device according to claim 10 .

Assignees

• Sharp Kk

Inventors

• Kamada Kentaro
• Matsui Keitaro
• Harada Masanobu

Classifications

• H05B47/10 Primary

  Controlling the light source · CPC title

• F21S2/00 Primary

  Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction · CPC title

• G02B6/0068 Primary

  Arrangements of plural sources, e.g. multi-colour light sources · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title

• G02B6/0026

  Wavelength selective element, sheet or layer, e.g. filter or grating · CPC title