Lighting device, display device, and television device that reduce unevenness in displayed color

• US 10,451,790 B2
• Filed: 03/15/2016
• Issued: 10/22/2019
• Est. Priority Date: 04/01/2015
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Gotou, Akira
• Primary Examiner(s): Mai, Anh T
• Assistant Examiner(s): Featherly, Hana S
• Application Number:
  US15/554,465
• Publication Number:
  US 20180039006A1
• Time in Patent Office: 1,316 Days
• Field of Search: 362606
• CPC Class Codes: F21S 2/00 Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/0088 of the light guide or other optical sheets in the package
• CPC Class Codes: G02B 6/009 of the light source in the package G02B6/0021 takes precedence
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials

Abstract

A backlight device (a lighting device) 12 includes LEDs (a light source) 17, a light guide plate 19 having a light entering end surface 19b that is a part of peripheral edge surfaces and through which light from the LEDs 17 enters and a light exiting plate surface 19a that is one of a pair of plate surfaces and through which light exits, a wavelength conversion sheet (a wavelength conversion member) 20 overlapping the light exiting plate surface 19a of the light guide plate 19 and containing phosphors that convert the light from the LEDs 17 to light with other wavelengths, and a color exhibit member 30 disposed on at least a part of a peripheral portion of the wavelength conversion sheet 20 and exhibiting a color same as or similar to a color of the light converted with wavelength conversion by the phosphors contained in the wavelength conversion sheet 20.

Claims

1. A lighting device comprising:

a light source emitting a first light;

a light guide plate having a light entering end surface that is a part of peripheral edge surfaces and through which the first light from the light source enters and a light exiting plate surface that is one of a pair of plate surfaces and through which the first light exits;

a wavelength conversion member overlapping the light exiting plate surface of the light guide plate and containing phosphors that convert the first light from the light source to a second light with other wavelengths; and

a color exhibit member disposed on at least a part of a peripheral portion of the wavelength conversion member and exhibiting a color same as or similar to a color of the second light converted by the phosphors contained in the wavelength conversion member.

2. The lighting device according to claim 1, wherein the color exhibit member has a higher absorption rate of light having a color same as or similar to a color that makes a complementary color pair with the color of the second light that is converted by the phosphors through the wavelength conversion member than an absorption rate of the light having a color same as or similar to the color of the second light that is converted by the phosphors through the wavelength conversion member.

3. The lighting device according to claim 1, wherein

the light source is configured to emit blue light,

the wavelength conversion member includes at least green phosphors and red phosphors, or yellow phosphors as the phosphors,

the green phosphors convert the blue light into green light with wavelength conversion and the red phosphors convert the blue light into red light with wavelength conversion, and the yellow phosphors convert the blue light into yellow light with wavelength conversion, and

the color exhibit member is configured to exhibit yellow or a similar color to yellow.

4. The lighting device according to claim 1, further comprising a frame including a frame portion that is between and supports peripheral portions of the light guide plate and the wavelength conversion member, wherein

the color exhibit member extends inward farther than the frame portion extends.

5. The lighting device according to claim 1, wherein the color exhibit member extends along an entire periphery of the peripheral portion of the wavelength conversion member.

6. The lighting device according to claim 5, wherein

the wavelength conversion member includes a wavelength conversion layer containing the phosphors, and a pair of protection layers having the wavelength conversion layer therebetween and protecting the wavelength conversion layer, and

the color exhibit member is configured to collectively hold peripheral portions of the wavelength conversion layer and the protection layers.

7. The lighting device according to claim 1, further comprising a support member supporting the wavelength conversion member and having a positioning member positioning the wavelength conversion member, wherein

the color exhibit member includes a positioning projection that partially projects from the peripheral portion of the wavelength conversion member and is in contact with the positioning member.

8. The lighting device according to claim 1, wherein the wavelength conversion member contains quantum dot phosphors as the phosphors.

9. A display device comprising:

the lighting device according to claim 1; and

a display panel displaying images using light from the lighting device.

10. A television device comprising the display device according to claim 9.

11. The lighting device according to claim 1, wherein the wavelength conversion member is a wavelength conversion sheet having a sheet surface that overlaps and is opposite the light exiting plate surface.

12. The lighting device according to claim 1, wherein the color exhibit member is configured to hold the peripheral portion of the wavelength conversion member.

13. The lighting device according to claim 12, wherein:

the wavelength conversion member includes;

a wavelength conversion layer containing the phosphors, and

a pair of protection layers having the wavelength conversion layer therebetween and protecting the wavelength conversion layer, and

the color exhibit member is configured to collectively hold peripheral portions of the wavelength conversion layer and the protection layers.

14. A lighting device comprising:

a light source emitting a first light;

a chassis in which the light source is arranged and that includes a bottom portion on an opposite side from a light emission surface side of the light source;

a wavelength conversion member disposed opposite the light emission surface and away from the light emission surface on a light exit side and containing phosphors that convert the first light from the light source to a second light with other wavelengths;

a reflecting member configured to reflect the first light from the light source toward the wavelength conversion member and at least including a bottom reflection portion disposed along the bottom portion and an extended reflection portion extending from the bottom reflection portion toward the wavelength conversion member; and

a color exhibit member disposed on at least a part of a peripheral portion of the wavelength conversion member and exhibiting a color same as or similar to a color that makes a complementary color pair with a color of the second light that is converted by the phosphors through the wavelength conversion member.

15. The lighting device according to claim 14, wherein the color exhibit member has a higher absorption rate of light having a color same as or similar to the color of the second light converted by the phosphors through the wavelength conversion member than an absorption rate of light having a color same as or similar to a color that makes a complementary color pair with the color of the second light converted by the phosphors through the wavelength conversion member.

16. The lighting device according to claim 14, wherein

the light source is configured to emit blue light,

the wavelength conversion member includes at least green phosphors and red phosphors, or yellow phosphors as the phosphors,

the green phosphors convert the blue light into green light with wavelength conversion and the red phosphors convert the blue light into red light with wavelength conversion, and the yellow phosphors convert the blue light into yellow light with wavelength conversion, and

the color exhibit member is configured to exhibit blue or a similar color to blue.

17. The lighting device according to claim 14, wherein the color exhibit member is disposed to overlap the extended reflection portion.

18. The lighting device according to claim 14, wherein the color exhibit member extends along an entire periphery of the peripheral portion of the wavelength conversion member.

19. The lighting device according to claim 14, wherein the wavelength conversion member is a wavelength conversion sheet.

20. The lighting device according to claim 14, further comprising a support member supporting the wavelength conversion member and having a positioning member positioning the wavelength conversion member, wherein

the color exhibit member includes a positioning projection that partially projects from the peripheral portion of the wavelength conversion member and is in contact with the positioning member.

21. The lighting device according to claim 14, wherein:

the light source includes a plurality of light sources; and

no light source is disposed on a section of the bottom portion overlapping the extended reflection portion.

22. The lighting device according to claim 21, wherein the extended reflection portion extends from an entire periphery of an outer edge of the bottom reflection portion.

23. The lighting device according to claim 14, wherein the extended reflection portion extends while being inclined with respect to the bottom reflection portion and the wavelength conversion member, and a distance between the wavelength conversion member and the extended reflection portion is greatest at an extended basal end of the extended reflection portion and is smallest at an extended distal end.