LIQUID CRYSTAL DISPLAY APPARATUS

• US 20170315405A1
• Filed: 10/02/2015
• Published: 11/02/2017
• Est. Priority Date: 10/10/2014
• 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: MASUDA, Masatsugu, FUJII, Hideaki, KAWAHARA, Takeshi, TANAKA, Toshiyuki, YOSHIMURA, Kenichi, YOSHIMURA, Makoto, MIYATA, Masataka, SHIOMOTO, Takehiro
• Granted Patent: US 10,261,360 B2
• Time in Patent Office: Days
• CPC Class Codes: C09B 11/04 derived from triarylmethanes , i.e. central C-atom is substituted by amino, cyano, alkyl
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/617 Silicates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: G02B 5/223 containing organic substances, e.g. dyes, inks or pigments
• CPC Class Codes: G02F 1/133357 Planarisation layers
• CPC Class Codes: G02F 1/133514 Colour filters
• 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 1/133624 characterised by their spectral emissions
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A liquid crystal display device includes: a liquid crystal display panel that includes red color filters, green color filters, and blue color filters; and an illumination device that illuminates the liquid crystal display panel with white light. The illumination device includes light-emitting elements that emit blue light, a green phosphor that absorbs a portion of the blue light emitted from the light-emitting elements and then emits green light, and a red phosphor that absorbs a portion of the blue light emitted from the light-emitting elements and then emits red light. The blue color filters are made of a colored material that contains a dye, and the chromaticity values x and y of the white light emitted from the illumination device satisfy the relationships 0.24<x and 0.24<y.

Claims

1. A liquid crystal display device, comprising:

a liquid crystal display panel including a red color filter, a green color filter, and a blue color filter; and

an illumination device illuminating the liquid crystal display panel with white light,

wherein the illumination device includes a light-emitting element that emits blue light, a green phosphor that absorbs a portion of the blue light emitted from the light-emitting element and then emits green light, and a red phosphor that absorbs a portion of the blue light emitted from the light-emitting element and then emits red light,

wherein the blue color filter is made of a colored material that contains a dye, and

wherein chromaticity values x, y of the white light emitted from the illumination device satisfy relationships 0.24<

x and 0.24<

y.

2. The liquid crystal display device according to claim 1, wherein a peak wavelength of an emission spectrum of the green phosphor is 520 nm to 540 nm.

3. The liquid crystal display device according to claim 1, wherein the green phosphor is a bivalent europium-activated oxynitride β

-SiAlON phosphor represented by a general formula (A);

Si_6-zAl_zO_zN_8-z;

Eu_x, where z and x satisfy relationships 0<

z<

4.2 and 0.003<

x<

0.03.

4. The liquid crystal display device according to claim 1, wherein a ratio Ia/Ib of an emission spectrum of the red phosphor is less than 0.1, where Ia is an integrated intensity at wavelengths greater than or equal to 650 nm and Ib is an integrated intensity over all wavelength regions.

5. The liquid crystal display device according to claim 1, wherein the red phosphor is a tetravalent manganese-activated fluoro-tetravalent metalate phosphor represented by a general formula (B):

M^I₂(M^II_1-hMn_h)F₆, where M^I is at least one alkali metal element selected from Li, Na, K, Rb, and Cs;

M^II is at least one tetravalent element selected from Ge, Si, Sn, Ti, and Zr; and

h satisfies the relationship 0.01<

h<

0.2.

6. The liquid crystal display device according to claim 1, wherein the dye contained in the colored material is a triphenylmethane dye.

7. The liquid crystal display device according to claim 1, wherein the colored material further contains a pigment.

8. The liquid crystal display device according to claim 1:

wherein an emission spectrum of the illumination device has peaks in wavelength regions of 442 nm to 453 nm, 525 nm to 535 nm, 611 nm to 615 nm, 629 nm to 633 nm, and 645 nm to 649 nm,

wherein a transmission spectrum of the red color filter exhibits a transmittance of less than or equal to 5% at wavelengths of 400 nm to 580 nm, exhibits an increase in transmittance at wavelengths of 580 nm to 585 nm, and exhibits a transmittance of greater than or equal to 80% at wavelengths of greater than or equal to 625 nm, and a wavelength at which the transmission spectrum of the red color filter exhibits a transmittance of greater than or equal to 50% is included in a range of 595 nm to 605 nm,

wherein a transmission spectrum of the green color filter has a peak in transmittance in a wavelength region of 505 nm to 525 nm, exhibits a transmittance of less than or equal to 5% at wavelengths of less than or equal to 465 nm and at wavelengths of 600 nm to 680 nm, and wavelengths at which the transmission spectrum of the green color filter exhibits a transmittance of 50% are respectively included in a range of 485 nm to 490 nm and a range of 556 nm to 562 nm, and

wherein a transmission spectrum of the blue color filter has a peak in transmittance in a wavelength region of 420 nm to 450 nm, exhibits a transmittance of 30% to 50% at a wavelength of 400 nm and a transmittance of 10% to 20% at a wavelength of 500 nm, and wavelengths at which the transmission spectrum of the blue color filter exhibits a transmittance of 50% are respectively included in a range of 400 nm to 410 nm and a range of 468 nm to 478 nm.

9. The liquid crystal display device according to claim 1:

wherein an emission spectrum of the illumination device has peaks in wavelength regions of 442 nm to 453 nm, 525 nm to 535 nm, 611 nm to 615 nm, 629 nm to 633 nm, and 645 nm to 649 nm,

wherein a transmission spectrum of the red color filter exhibits a transmittance of less than or equal to 10% at wavelengths of 400 nm to 560 nm, exhibits an increase in transmittance at wavelengths of 560 nm to 570 nm, and exhibits a transmittance of greater than or equal to 90% at wavelengths of greater than or equal to 620 nm, and a wavelength at which the transmission spectrum of the red color filter exhibits a transmittance of 50% is included in a range of 588 nm to 593 nm,

wherein a transmission spectrum of the green color filter has a peak in transmittance in a wavelength region of 505 nm to 525 nm, exhibits a transmittance of less than or equal to 5% at wavelengths of less than or equal to 465 nm and at wavelengths of 600 nm to 680 nm, and wavelengths at which the transmission spectrum of the green color filter exhibits a transmittance of 50% are respectively included in a range of 485 nm to 490 nm and a range of 557 nm to 562 nm, and

wherein a transmission spectrum of the blue color filter has a peak in transmittance in a wavelength region of 415 nm to 460 nm, exhibits a transmittance of 50% to 70% at a wavelength of 400 nm and a transmittance of 35% to 45% at a wavelength of 500 nm, and a wavelength at which the transmission spectrum of the blue color filter exhibits a transmittance of 50% is included in a range of 490 nm to 500 nm.

10. The liquid crystal display device according to claim 1:

wherein an emission spectrum of the illumination device has peaks in wavelength regions of 442 nm to 453 nm, 535 nm to 545 nm, 611 nm to 615 nm, 629 nm to 633 nm, and 645 nm to 649 nm,

wherein a transmission spectrum of the red color filter exhibits a transmittance of less than or equal to 5% at wavelengths of 400 nm to 575 nm, exhibits an increase in transmittance at wavelengths of 575 nm to 580 nm, and exhibits a transmittance of greater than or equal to 90% at wavelengths of greater than or equal to 620 nm, and a wavelength at which the transmission spectrum of the red color filter exhibits a transmittance of greater than or equal to 50% is included in a range of 595 nm to 605 nm,

wherein a transmission spectrum of the green color filter has a peak in transmittance in a wavelength region of 512 nm to 532 nm, exhibits a transmittance of less than or equal to 5% at wavelengths of less than or equal to 470 nm and at wavelengths of 600 nm to 670 nm, and wavelengths at which the transmission spectrum of the green color filter exhibits a transmittance of 50% are respectively included in a range of 488 nm to 493 nm and a range of 561 nm to 567 nm, and

wherein a transmission spectrum of the blue color filter has a peak in transmittance in a wavelength region of 415 nm to 460 nm, exhibits a transmittance of 50% to 70% at a wavelength of 400 nm and a transmittance of 48% to 58% at a wavelength of 500 nm, and a wavelength at which the transmission spectrum of the blue color filter exhibits a transmittance of 50% is included in a range of 496 nm to 505 nm.

11. The liquid crystal display device according to claim 1:

wherein an emission spectrum of the illumination device has peaks in wavelength regions of 442 nm to 453 nm, 535 nm to 545 nm, 611 nm to 615 nm, 629 nm to 633 nm, and 645 nm to 649 nm,

wherein a transmission spectrum of the red color filter exhibits a transmittance of less than or equal to 5% at wavelengths of 400 nm to 560 nm, exhibits an increase in transmittance at wavelengths of 560 nm to 570 nm, and exhibits a transmittance of greater than or equal to 90% at wavelengths of greater than or equal to 620 nm, and a wavelength at which the transmission spectrum of the red color filter exhibits a transmittance of greater than or equal to 50% is included in a range of 590 nm to 595 nm,

wherein a transmission spectrum of the green color filter has a peak in transmittance in a wavelength region of 515 nm to 535 nm, exhibits a transmittance of less than or equal to 10% at wavelengths of less than or equal to 465 nm and at wavelengths of 625 nm to 670 nm, and wavelengths at which the transmission spectrum of the green color filter exhibits a transmittance of 50% are respectively included in a range of 477 nm to 482 nm and a range of 590 nm to 595 nm, and

wherein a transmission spectrum of the blue color filter has a peak in transmittance in a wavelength region of 415 nm to 460 nm, exhibits a transmittance of 50% to 70% at a wavelength of 400 nm and a transmittance of 45% to 55% at a wavelength of 500 nm, and a wavelength at which the transmission spectrum of the blue color filter exhibits a transmittance of 50% is included in a range of 495 nm to 505 nm.

12. The liquid crystal display device according to claim 1, wherein thicknesses of the red color filter, the green color filter, and the blue color filter are each less than or equal to 2.5 μ

m.

13. The liquid crystal display device according to claim 1,

wherein the liquid crystal display panel includes a color filter substrate that includes the red color filter, the green color filter, and the blue color filter, and

wherein the color filter substrate further includes a planarizing layer formed covering the red color filter, the green color filter, and the blue color filter.

14. The liquid crystal display device according to claim 1, wherein images are displayed using a lateral electric field mode.