Color filter and color LCD apparatus having red filter with a peak wavelength between 685 nm and 690 nm and a red light source having a peak wavelength of between 640 nm and 645 nm

• US 7,808,585 B2
• Filed: 07/12/2005
• Issued: 10/05/2010
• Est. Priority Date: 07/15/2004
• Status: Active Grant

• Current Assignee: Saturn Licensing LLC (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ota, Yutaka, Nakatsue, Takehiro, Kakinuma, Koichiro, Haga, Shuichi, Matsumoto, Tatsuhiko, Oku, Takashi, Tagawa, Yasuhiro, Arai, Takeo
• Primary Examiner(s): HEYMAN, JOHN S
• Application Number:
  US11/631,543
• Publication Number:
  US 20080186433A1
• Time in Patent Office: 1,911 Days
• Field of Search: 349106-109
• US Class Current: 349/106
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133624 characterised by their spectral emissions

Abstract

A color filter (19) used in a transmissive color liquid crystal display panel of a color liquid crystal display (LCD) apparatus. This color filter (19) is constituted by a tristimulus color filter for wavelength-selecting and transmitting red light, green light and blue light. Mixing of blue color and red color is prohibited by not having the transmission wavelength band of the red filter CFR overlaid substantially on the transmission wavelength band of the blue filter CFB.

Claims

1. A color filter of a transmissive color liquid crystal display panel, the color filter comprising a tristimulus color filter for wavelength-selecting and transmitting red light, green light and blue light, the color filter comprising:

a red filter having a peak wavelength of a transmission wavelength band Fpr such that 685 nm≦

Fpr≦

690 nm;

wherein overlaying of a transmission wavelength band of a red filter on a transmission wavelength band of a blue filter is substantially precluded for preventing color mixing of blue and red colors.

2. The color filter according to claim 1, wherein said red filter has transmittance for light with a wavelength of 400 nm set so as to be less than or equal to 6%.

3. The color filter according to claim 1, further comprising a blue filter having a peak wavelength of a transmission wavelength band Fpb such that 440 nm≦

Fpb≦

460 nm.

4. A color liquid crystal display apparatus including a transmissive color liquid crystal display panel provided with a color filter, the color filter comprising a tristimulus filter for wavelength-selecting and transmitting red light, green light and blue light, and a backlight device for illuminating said color liquid crystal display panel with white light from a backside thereof, the color liquid crystal display apparatus comprising:

a light source comprising a red light emitting diode to emit red light and having a peak wavelength λ

pr such that 640 nm≦

λ

pr≦

645 nm;

wherein overlaying of a transmission wavelength band of a red filter on a transmission wavelength band of a blue filter is substantially precluded for preventing color mixing of blue and red colors.

5. The color liquid crystal display apparatus according to claim 4, wherein said red filter has transmittance for light with a wavelength of 400 nm set so as to be less than or equal to 6%.

6. The color liquid crystal display apparatus according to claim 4, wherein said backlight device includes a light source comprising a red light emitting diode to emit red light, a green light emitting diode to emit green light and a blue light emitting diode to emit blue light and having a peak wavelength λ

pb such that 440 nm≦

λ

pb≦

460 nm, and

color mixing means for mixing the red light, green light and blue light, radiated from said light source, to create said white light.

7. The color liquid crystal display apparatus according to claim 4, further comprising a blue filter having a peak wavelength of a transmission wavelength band Fpb such that 440 nm≦

Fpb≦

460 nm.

8. A color liquid crystal display apparatus including a transmissive color liquid crystal display panel provided with a color filter, the color filter comprising a tristimulus filter for wavelength-selecting and transmitting red light, green light and blue light, and a backlight device for illuminating said color liquid crystal display panel with white light from a backside thereof, wherein

said backlight device includes

a light source comprising a red light emitting diode to emit red light and having a peak wavelength λ

pr such that 640 nm≦

λ

pr≦

645 nm, a green light emitting diode to emit green light and having a peak wavelength λ

pg such that 525 nm≦

λ

pg≦

530 nm, and a blue light emitting diode to emit blue light and having a peak wavelength λ

pb such that 440 nm≦

λ

pb≦

450 nm, and

a color mixing unit for mixing the red light, green light and blue light radiated from said light source to create said white light, and

said color filter comprises a red filter having a peak wavelength of a transmission wavelength band Fpr such that 685 nm≦

Fpr≦

690 nm, said transmission wavelength band of said red filter not substantially overlapping with a transmission wavelength band of said blue filter to prevent color mixing of blue and red colors, a green filter having a peak wavelength of a transmission wavelength band Fpg of 530 nm and the half-value width of a transmission wavelength band Fhwg such that 80 nm≦

Fhwg≦

100 nm, and a blue filter having a peak wavelength of a transmission wavelength band Fpb such that 440 nm≦

Fpb≦

460 nm.

9. The color liquid crystal display apparatus according to claim 8, wherein said red filter has transmittance for light with the wavelength of 400 nm set so as to be less than or equal to 6%.