Active matrix type liquid crystal display apparatus

• US 7,433,012 B2
• Filed: 12/13/2005
• Issued: 10/07/2008
• Est. Priority Date: 10/23/1995
• Status: Expired due to Fees

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Yanagawa, Kazuhiko, Kondo, Katsumi, Ashizawa, Keiichiro, Utsumi, Yuka, Hiyama, Ikuo, Itoh, Osamu, Ohe, Masahito
• Primary Examiner(s): Dudek; James A
• Application Number:
  US11/299,699
• Publication Number:
  US 20060087482A1
• Time in Patent Office: 1,029 Days
• Field of Search: 349/177, 349/181
• US Class Current: 349/181
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G09G 2300/0434 Flat panel display in which a field is applied parallel to the display plane
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display apparatus includes a liquid crystal panel including a pair of polarizers, and a back light provided at a back side of said liquid crystal panel. The liquid crystal panel is an active matrix type liquid crystal panel enabling display and has a characteristic of spectral transmittance required to satisfy the following equation, ×>y, when a drive voltage is applied thereto so as to vary from a dark state to a light state, in which “x” is a value of the transmittance in the liquid crystal panel at a wavelength which corresponds to one of 490 nm and 500 nm, and “y” is a value of the transmittance in the liquid crystal panel at a wavelength which corresponds to 545 nm.

Claims

1. A liquid crystal display apparatus comprising:

a liquid crystal panel including a pair of polarizers; and

a back light having a light source provided at a back side of said liquid crystal panel for illumination thereof;

wherein said liquid crystal panel is an active matrix type liquid crystal panel enabling display and has a characteristic of spectral transmittance required to satisfy the following equation, x>

y, when a drive voltage is applied thereto so as to vary at all voltages of the drive voltage from a dark state to a light state, where;

“

x”

is a value of the transmittance in said liquid crystal panel at a wavelength which corresponds to one of 490 nm and 500 nm; and

“

y”

is a value of the transmittance in said liquid crystal panel at a wavelength which corresponds to 545 nm.

2. A liquid crystal display apparatus according to claim 1, wherein a range of wavelengths designated for blue light illuminated from said light source corresponds to 400 nm to 500 nm, and a range of wavelengths designated for green light illuminated from said light source corresponds to 500 nm to 600 nm.

3. A liquid crystal display apparatus according to claim 1, wherein:

said pair of polarizers is arranged so as to sandwich a pair of substrates in said liquid crystal panel; and

a birefringent film is arranged between a polarizer and a substrate.

4. A liquid crystal display apparatus according to claim 3, further comprising a plurality of electrodes provided on at least one of said pair of substrates in said liquid crystal panel to produce an electric field substantially in parallel with surfaces of said pair of substrates.

5. A liquid crystal display apparatus according to claim 1, wherein “

x”

is a value of the transmittance in said liquid crystal panel at a wavelength which corresponds to 490 nm.

6. A liquid crystal display apparatus according to claim 1, wherein “

x”

is a value of the transmittance in said liquid crystal panel at a wavelength which corresponds to 500 nm.

7. A liquid crystal display apparatus comprising:

a liquid crystal panel including a pair of polarizers; and

a back light having a light source provided at a back side of said liquid crystal panel for illumination thereof;

wherein said liquid crystal panel is an active matrix type liquid crystal panel enabling display and has a characteristics of spectral transmittance required to satisfy the following equation, x>

y, when a drive voltage is applied thereto so as to vary at all voltages of the drive voltage from a dark state to a light state, where;

“

x”

is a value of the transmittance in said liquid crystal panel at a wavelength which corresponds to a longest wavelength in the range of wavelengths designated for blue light illuminated from said light source;

“

y”

is a value of the transmittance in said liquid crystal panel at a wavelength which corresponds to a maximum value of the intensity in the range of wavelengths designated for green light illuminated from said light source.

8. A liquid crystal display apparatus according to claim 7, wherein the range of wavelengths designated for blue light illuminated from said light source corresponds to 400 nm to 500 nm, and the range of wavelengths designated for green light illuminated from said light source corresponds to 500 nm to 600 nm.

9. A liquid crystal display apparatus according to claim 8, wherein:

said pair of polarizers is arranged so as to sandwich a pair of substrates in said liquid crystal panel; and

a birefringent film is arranged between a polarizer and a substrate.

10. A liquid crystal display apparatus according to claim 9, further comprising a plurality of electrodes provided on at least one of said pair of substrates in said liquid crystal panel to produce an electric field substantially in parallel with surfaces of said pair of substrates.