DISPLAY DEVICE AND TELEVISION RECEIVER

• US 20130002963A1
• Filed: 02/09/2011
• Published: 01/03/2013
• Est. Priority Date: 03/25/2010
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yokota, Masashi
• Application Number:
  US13/636,285
• Publication Number:
  US 20130002963A1
• Time in Patent Office: Days
• US Class Current: 348/728
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 2202/046 fluorescent

Abstract

It is an object of the present invention to obtain high brightness and high color reproducibility in a liquid crystal display device. A liquid crystal display device 10 according to the present invention includes a liquid crystal panel 11 and a backlight unit 12. The liquid crystal panel 11 includes a pair of substrates 11a and 11b, and a liquid crystal layer 11c. The liquid crystal layer 11C includes liquid crystal between the substrates 11a and 11b. The liquid crystal is a substance having optical characteristics that vary with application of an electric field. The backlight unit 12 includes a light source. The back light unit 12 is configured to irradiate light onto the liquid crystal panel 11. At least one of the substrates 11a and 11b of the liquid crystal panel 11 includes a color filter 19 with a plurality of color sections R, G, B, and Y that exhibit the colors of blue, green, red, and yellow, respectively. The backlight unit 12 includes LEDs 24 as the light source. Each LED 24 includes an LED element as a light emitting source and a phosphor configured to emit light when excited by the light from the LED element. The phosphor includes at least two types of phosphors with different dominant emission wavelengths in a range of 480 nm to 580 nm.

Claims

1. A display device comprising:

a display panel including a pair of substrates and a substance provided between the substrates, the substance having optical characteristics that vary with application of an electric field; and

a lighting device including an LED as a light source, the LED being configured to irradiate light toward the display panel, wherein

one of the substrates of the display panel includes a color filter including a plurality of blue, green, red, and yellow color sections,

the LED includes an LED element as a light emitting source and phosphors configured to light when excited by light from the LED element, the phosphors including at least two types of phosphors with different dominant emission wavelengths in a range of 480 nm to 580 nm.

2. The display device according to claim 1, wherein the at least two types of phosphors have the dominant emission wavelengths in a range of 500 nm to 560 nm.

3. The display device according to claim 2, wherein the at least two types of phosphors include a phosphor with the dominant emission wavelength of 530 nm.

4. The display device according to claim 2, wherein the at least two types of phosphors include a phosphor with the dominant emission wavelength of 540 nm.

5. The display device according to claim 2, wherein the at least two types of phosphors include a first phosphor with the dominant emission wavelength of 530 nm and a second phosphor with the dominant emission wavelength of 540 nm.

6. The display device according to claim 5, wherein the first and second phosphors are contained in substantially equal amounts.

7. The display device according to claim 1, wherein the at least two types of phosphors include a first phosphor with the dominant emission wavelength on a relatively shorter wavelength side and relatively far from 555 nm, and a second phosphor with the dominant emission wavelength on a relatively longer wavelength side and relatively close to 555 nm.

8. The display device according to claim 7, wherein the first and second phosphors are contained in substantially equal amounts.

9. The display device according to claim 1, wherein the at least two types of phosphors have a difference of 10 nm in the dominant emission wavelength.

10. The display device according to claim 1, wherein the at least two types of phosphors include a SiAlON-based phosphor.

11. The display device according to claim 10, wherein the SiAlON-based phosphor is a β

-SiAlON.

12. The display device according to claim 11, wherein the β

-SiAlON uses Eu as an activator.

13. The display device according to claim 10, wherein

the at least two types of phosphors include a first phosphor with the dominant emission wavelength on a relatively shorter wavelength side and a second phosphor with the dominant emission wavelength on a relatively longer wavelength side, and

the first phosphor and the second phosphor are both SiAlON-based phosphors.

14. The display device according to claim 1, wherein the phosphors further include at least one type of phosphor with the dominant emission wavelength in a range of 580 nm to 780 nm.

15. The display device according to claim 14, wherein the at least one type of phosphor has the dominant emission wavelength in a range of 600 nm to 780 nm.

16. The display device according to claim 15, wherein the at least one type of phosphor has the dominant emission wavelength in a range of 610 nm to 650 nm.

17. The display device according to claim 15, wherein the at least one type of phosphor is a CASN-based phosphor.

18. The display device according to claim 17, wherein the CASN-based phosphor is a CASN (CaAlSiN₃:

Eu).

19. The display device according to claim 1, wherein the LED element has the dominant emission wavelength in a range of 380 nm to 480 nm.

20. The display device according to claim 19, wherein the LED element has the dominant emission wavelength in a range of 440 nm to 460 nm.

21. The display device according to claim 1, wherein the color filter is configured such that each chromaticity of blue, green, red, and yellow output lights obtained by passing the light from the LED through the color sections in the color filter lies outside a common region of a NTSC chromaticity region according to a NTSC standard and a EBU chromaticity region according to a EBU standard in a CIE1976 chromaticity diagram.

22. The display device according to claim 1, wherein a chromaticity region of output light obtained by passing the light from the LED through the color sections in the color filter occupies 70% or more of a NTSC chromaticity region according to the NTSC standard.

23. The display device according to claim 1, wherein

the lighting device includes a chassis that houses the LED and an optical member, the chassis including a bottom portion arranged on a side opposite to the light output side of the LED, and

the optical member is arranged on the light output side in an opposed manner with respect to both the bottom portion and the LED.

24. The display device according to claim 23, wherein the LED includes a diffuser lens on the light output side of the LED to diffuse the light from the LED.

25. The display device according to claim 1, wherein

the lighting device further includes a light guide member with an end portion opposed to the LED, and

the light guide member guides the light from the LED toward the display panel through the light guide member.

26. The display device according to claim 25, wherein

the light guide member includes an elongated light entrance surface on the end portion opposed to the LED,

the LED includes a lens member that covers the light output side of the LED and diffuses light, and

the lens member is opposed to the light entrance surface of the light guide member and curved along the longitudinal direction of the light entrance surface to be convex toward the light guide member.

27. The display device according to claim 26, wherein the lighting device further includes a reflection sheet between the LED and the light guide member along the longitudinal direction of the light entrance surface.

28. The display device according to claim 1, wherein the display panel is a liquid crystal panel including liquid crystal as the substance, the optical characteristics of which vary with application of an electric field.

29. A television receiver comprising:

the display device according to claim 1; and

a reception unit configured to receive a television signal.

30. The television receiver according to claim 29, further comprising an image conversion circuit converting a television image signal output from the reception unit into an image signal for the respective colors of blue, green, red, or yellow.