SCREEN AND PROJECTION DISPLAY APPARATUS USING THE SAME

• US 20020012082A1
• Filed: 10/01/1997
• Published: 01/31/2002
• Est. Priority Date: 03/16/1994
• Status: Active Grant

• Current Assignee: Hisashi Yamaguchi, Takeshi Goto, Tetsuya Kobayashi, Toshihiro Suzuki
• Original Assignee: Hisashi Yamaguchi, Takeshi Goto, Tetsuya Kobayashi, Toshihiro Suzuki
• Inventors: SUZUKI, TOSHIHIRO, KOBAYASHI, TETSUYA, GOTO, TAKESHI, YAMAGUCHI, HISASHI
• Granted Patent: US 6,392,726 B2
• Time in Patent Office: Days
• US Class Current: 349/86
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G03B 21/62 Translucent screens

Abstract

A screen has a screen main body, a power supply and a voltage regulator. The screen main body has a Flesnel lens, a polymer dispersed liquid crystal unit and a lenticular lens 15. The liquid crystal unit includes a polymer dispersed liquid crystal and a pair of transparent electrodes which sandwich the polymer dispersed liquid crystal. By operating the voltage regulator, a voltage applied to the electrodes is adjusted so that a gain of the liquid crystal is controlled.

Claims

1. A screen comprising a gain controller for changing a ratio (gain) of luminance at a light-outgoing face of the screen to illuminance at a light-incident face of the screen.

2. The screen as claimed in claim 1, wherein said gain controller comprises:

a pair of transparent electrodes opposite to each other;

.

a scattering liquid crystal disposed between said pair of transparent electrodes; and

a voltage regulator for adjusting a voltage applied to said pair of transparent electrodes.

3. The screen claimed in claim 2, further comprising:

a Flesnel lens at which an image-forming light is incident on the screen; and

a lenticular lens at which the image-forming light outgoes from the screen,

wherein said gain controller is disposed between said lenticular lens and said Flesnel lens.

4. The screen as claimed in claim 2, further comprising:

a Flesnel lens at which the image-forming light is incident on the screen,

wherein said gain controller is provided to face the surface of said Flesnel lens from which surface the image-forming light outgoes, and

the scattering liquid crystal constituting a part of said gain controller has a lenticular lens surface on its face from which face the image-forming light outgoes.

5. The screen as claimed in claim 2, further comprising:

a Flesnel lens at which the image-forming light is incident on the screen; and

a transparent base which has a surface having discrete depressions, said surface facing said Flesnel lens,

wherein said gain controller is provided on said surface of said transparent base which surface faces said Flesnel lens, and

the scattering liquid crystal constituting a part of said gain controller has a lenticular lens surface on its face from which face the image-forming light outgoes.

6. The screen as claimed in claim 2, further comprising a reflecting layer for reflecting the image-forming light emitted by a projector,

wherein said gain controller is provided between said projector and said reflecting layer.

7. The screen as claimed in claim 1, further comprising a brightness detector for detecting brightness of the surroundings,

wherein an output from said brightness detector is used to operate said gain controller.

8. The screen as claimed in claim 2, further comprising a brightness detector for detecting brightness of the surroundings,

wherein an output from said brightness detector is used to operate said gain controller.

9. The screen as claimed in claim 6, further comprising a brightness detector for detecting brightness of the surroundings,

wherein an output from said brightness detector is used to operate said gain controller.

10. A projection display apparatus comprising:

a body;

a projector provided in said body; and

screen attached to said body, said screen comprising a gain controller for changing a ratio (gain) of luminance at a light-outgoing face of the screen to illuminance at a light-incident face of the screen.

11. The projection display apparatus as claimed in claim 10,

wherein said gain controller of said screen comprises:

a pair of transparent electrodes opposite to each other;

a scattering liquid crystal disposed between said pair of transparent electrodes; and

a voltage regulator for adjusting a voltage applied to said pair transparent electrodes.

12. The projection display apparatus as claimed in claim 11,

wherein said screen further comprises:

a Flesnel lens at which an image-forming light is incident on the screen; and

a lenticular lens at which the image-forming light outgoes from the screen, and

said gain controller is disposed between said lenticular lens and said Flesnel lens.

13. The projection display apparatus as claimed in claim 11,

wherein said screen fur her comprises:

a Flesnel lens at which the image-forming light is incident on the screen, and

said gain controller is provided to face the surface of said Flesnel lens from which surface the image-forming light outgoes, and

the scattering liquid crystal constituting a part of said gain controller has a lenticular lens surface of its face from which face the image-forming light outgoes.

14. The projection display apparatus as claimed in claim 11

wherein said screen further comprises:

a Flesnel lens at which the image-forming light is incident on the screen; and

a transparent base which has a surface having discrete depressions, said surface facing said Flesnel lens, and

said gain controller is provided on said surface of said transparent base which surface faces said Flesnel lens, and

the scattering liquid crystal constituting a part of said gain controller has a lenticular lens surface on its face from which face the image-forming light outgoes.

15. The projection display apparatus as claimed in claim 10, wherein said screen further comprises a brightness detector for detecting brightness of the surroundings, and

an output from said brightness detector is used to operate said gain controller.

16. The projection display apparatus as claimed in claim 11, wherein said screen further comprises a brightness detector for detecting brightness of the surroundings, and

an output from said brightness detector is used to operate said gain controller.

17. A projection display apparatus comprising:

a body;

a projector provided in said body; and

a screen having a gain controller for changing reflecting capability of the screen;

wherein said screen further comprises a reflecting layer for reflecting the image-forming light emitted by said projector, and

said gain controller is provided between said projector and said reflecting layer.

18. The projection display apparatus as claimed in claim 17, wherein said screen further comprises a brightness detector for detecting brightness of the surroundings, and

an output from said brightness detector is used to operate said gain controller.

19. A display method in a projection display apparatus having a projector and a screen, wherein the screen has a gain controller, said display method comprising the step of:

adjusting a gain of the screen by using said gain controller.

20. The display method as claimed in claim 19, wherein said gain controller has a scattering liquid crystal being disposed between a pair of transparent electrodes, and the adjusting of the gain being carried out by adjusting a voltage applied to said pair of transparent electrodes.