Display device and electronic apparatus using the same

• US 6,359,668 B1
• Filed: 01/13/1999
• Issued: 03/19/2002
• Est. Priority Date: 05/14/1997
• Status: Expired due to Term

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Sakura, Seiichi, Iijima, Chiyoaki, Tsuchihashi, Toshihiko
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Qi, Mike
• Application Number:
  US09/214,992
• Time in Patent Office: 1,161 Days
• Field of Search: 349/8, 349/162, 349/106, 349/112, 349/61, 349/62, 349/63, 349/64, 349/65
• US Class Current: 349/61
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one

Abstract

A retardation film 30 and an upper polarized light separator 20 are provided on the upper side of a liquid crystal cell 10. A diffuser 40, a lower polarized light separator 50, a color filter 60, a PET film 70 and an Al deposited film 80 are provided on the lower side of the liquid crystal cell 10. As the upper polarized light separator 20 and the lower polarized light separator 50, a polarized light separator (reflective polarizer) is used, which reflects linearly-polarized light in one direction as linearly-polarized light in the one direction, and transmits linearly-polarized light in another direction perpendicular to the one direction as linearly-polarized light in the other direction. The light emitted from LED 120 is introduced into a light guide plate 130 between the upper polarized light separator 20 and the retardation film 30 through a light guide 110. Then the light is emitted from the lower side of the light guide plate 130 to the liquid crystal cell 10.

Claims

1. A display device comprising:

a variable transmission polarization axis device;

a first polarized light separator disposed on a first side of said variable transmission polarization axis device, said first polarized light separator transmitting first linearly-polarized light and reflecting other linearly-polarized light;

a second polarized light separator disposed on a second side of said variable transmission axis device, said second polarized light separator transmitting second linearly polarized light and reflecting or absorbing other linearly polarized light; and

a light source for introducing light between said first and second polarized light separators said light guide including a transmissive light guide plate interdisposed between said second polarized light separator and said variable transmission polarization axis device.

2. The display device of claim 1 wherein said first polarized light separator further comprises a reflective polarizer.

3. The display device of claim 1 wherein said second polarized light separator further comprises a reflective polarizer.

4. The display device of claim 1 further comprising:

a color filter disposed on a first side of said first polarized light separator opposite said variable transmission axis device for emitting light in a first wavelength range from said first polarized light separator to said second polarized light separator.

5. The display device of claim 4 further comprising:

a reflector disposed on a first side of said color filter opposite said first polarized light separator for reflecting said light in said first wavelength range toward said color filter.

6. The display device of claim 1 further comprising:

an absorber disposed on a first side of said first polarized light separator opposite said variable transmission polarization axis device for absorbing light in a visible light region.

7. The display device of claim 1 further comprising:

a diffusion layer interdisposed between said first polarized light separator and said variable transmission polarization axis device.

8. The display device of claim 1 further comprising a light guide optically interconnecting said light source and said light guide plate.

9. The display device of claim 1 wherein said light guide plate further comprises a transmissive flat plate having a plurality of projections extending therefrom.

10. The display device of claim 1 wherein said variable transmission polarization axis device further comprises a liquid crystal.