Projector apparatus with mirror means

• US 4,875,064 A
• Filed: 07/30/1987
• Issued: 10/17/1989
• Est. Priority Date: 08/06/1986
• Status: Expired due to Term

• Current Assignee: Casio Computer Corporation (Casio Computer Company Limited)
• Original Assignee: Casio Computer Company Limited
• Inventors: Nakakusu, Tohru, Sato, Makoto, Umeda, Osamu, Shimazaki, Tatsuo
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Scanlon, Patrick R.
• Application Number:
  US07/079,883
• Time in Patent Office: 810 Days
• Field of Search: 353/74, 353/77, 353/78, 353/79, 353/98, 353/30, 353/31, 353/37, 353/122, 353/27 R, 350/331 R, 350/338, 350/127, 350/128, 358/231, 358/232, 358/233, 358/236, 358/237
• US Class Current: 353/78
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: G02B 5/0215 the surface having a regular structure
• CPC Class Codes: G02B 5/0221 the surface having an irregular structure G02B5/0226 takes precedence
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: G03B 21/625 Lenticular translucent screens
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A projection lens, for enlarging and projecting an image displayed on a liquid crystal display panel onto a transmission type screen provided at a display window of a projector case, is arranged so that its optical axis is perpendicular to the optical axis of projection toward the transmission type screen. At least one mirror, for reflecting an image projected through the projection lens toward the transmission type screen, is arranged between the projection lens and the transmission type screen. The liquid crystal display panel is arranged such that its optical axis is perpendicular to the optical axis of the projection lens. At least one mirror, for reflecting an image displayed on the liquid crystal display panel toward the projection lens, is arranged between the liquid crystal display panel and the projection lens.

Claims

1. A projector apparatus including, within a case having a display window equipped with a transmission type screen, a transmission type liquid crystal display panel, a light source means for illuminating said liquid crystal display panel from behind, and a projection lens means for projecting a display image of said liquid crystal display panel as an enlarged image on said transmission type screen, said projector apparatus comprising:

a first mirror means for reflecting light emitted from said light source to be incident substantially perpendicular to said liquid crystal display panel;

a focusing lens means for focusing light transmitted through said liquid crystal display panel onto said projection lens means;

a second mirror means for reflecting the focused light in the direction of an optical axis of said projection lens means to be incident on said projection lens means;

a third mirror means for reflecting the light projected from said projection lens means in a direction parallel to said transmission type screen;

a fourth mirror means for reflecting the light reflected by said third mirror means toward said transmission type screen; and

wherein a plane is defined by light reflected from the first mirror means to the second mirror means and on to the third mirror means, said first, second and third mirror means each bend light that is respectively incident thereon by 90°

in said plane, and said fourth mirror means reflects light in a direction perpendicular to said plane.

2. An apparatus according to claim 1, wherein said apparatus further comprises correction means for correcting the light emitted from said light source means to be parallel beams and to be incident on said liquid crystal display panel.

3. An apparatus according to claim 2, wherein said correction means comprises a parabolic reflector for reflecting the light emitted from said light source means to be parallel beams.

4. An apparatus according to claim 2, wherein said correction means comprises a condenser lens, arranged between said first mirror means and said liquid crystal display panel, for correcting the light reflected by said first mirror means into parallel beams to be incident on said liquid crystal display panel.

5. An apparatus according to claim 1, wherein said plane is substantially parallel to said transmission type screen.

6. An apparatus according to claim 1, wherein said focusing lens means is Fresnel lens.

7. A projector apparatus including, within a case having a display window equipped with a transmission type screen, a transmission type liquid crystal display panel, a light source means for illuminating said liquid crystal display panel from behind, and a projection lens means for projecting a display image of said liquid crystal display panel as an enlarged image on said transmission type screen, said projector apparatus comprising:

a first mirror means for reflecting light emitted from said light source means to be incident substantially perpendicular to said liquid crystal display panel;

a focusing lens means for focusing light transmitted through said liquid crystal display panel onto said projection lens means;

a second mirror means for reflecting the focused light in the direction of an optical axis of said projection lens means to be incident on said projection lens means;

a third mirror means for reflecting the light projected from said projection lens means in a direction parallel to said transmission type screen;

a fourth mirror means for reflecting the light reflected by said third mirror means toward said transmission type screen; and

wherein said light source is arranged in an upper portion of said case and behind said fourth mirror means.

8. An apparatus according to claim 7, wherein said transmission type screen comprises a large number of lenticular lenses on its surface.

9. An apparatus according to claim 7, wherein said transmission type screen has a Fresnel lens on its back surface.

10. An apparatus according to claim 7, wherein said transmission type screen is molded integrally with a lenticular lens and a Fresnel lens.

11. A projector apparatus including, within a case having a display window equipped with a transmission type screen, a transmission type liquid crystal display panel, a light source means for illuminating said liquid crystal display panel from behind, and a projection lens means for projecting a display image of said liquid crystal display panel as an enlarged image on said transmission type screen, said projector apparatus comprising:

at least one mirror means, arranged between said projection lens means and said transmission type screen, for reflecting the image projected by said projection lens means toward said transmission type screen;

at least one mirror means, arranged between said liquid crystal display panel and said projection lens means, for reflecting a display image from said liquid crystal display panel toward said projection lens means;

said projection lens means being arranged such that its optical axis is perpendicular to a projection axis toward said transmission type screen;

said liquid crystal display panel being arranged such that its optical axis intersects with the optical axis of said projection lens means; and

wherein said light source means is located at an upper side of said case and at the rear of the at least one mirror means arranged between the projection lens means and the transmission type screen.

12. An apparatus according to claim 11 wherein said apparatus further comprises correction means for correcting light emitted from said light source means to be parallel beams and to be incident on said liquid crystal display panel.

13. An apparatus according to claim 11 wherein said apparatus further comprises a focusing lens for focusing the light transmitted through said liquid crystal display panel onto said projection lens means.

14. An apparatus according to claim 11, wherein said transmission type screen comprises a large number of lenticular lenses formed on its surface.

15. An apparatus according to claim 11, wherein said transmission type screen has a Fresnel lens on its back surface.

16. An apparatus according to claim 11, wherein said transmission type screen is molded integrally with a lenticular lens and a Fresnel lens.

17. A projector apparatus comprising:

a case;

a transmission type screen provided on a predetermined surface of said case, to constitute a display window;

a display device arranged inside said case;

a projection lens for enlarging and projecting an image displayed on said display device, onto said transmission type screen; and

at least one mirror for reflecting the image projected through said projection lens, toward said transmission type screen,

said transmission type screen having a lenticular lens which is formed on a screen surface and is constituted by a plurality of lens units each having a lens portion at a top portion and total-reflection surfaces on two side surfaces, and leading surfaces, which stand at an angle larger than an angle of inclination of said total-reflection surface, being formed at upper end sides of said total-reflection surfaces on the sidesurfaces of each of said lens units.

18. A projector apparatus comprising:

a case;

a transmission type screen provided on a predetermined surface of said case with its body being in a given plane to constitute a display window;

a display device arranged inside said case;

a projection lens for enlarging and projecting an image displayed on said display device, onto said transmission type screen; and

at least one mirror for reflecting the image projected through said projection lens toward said transmission type screen,

said transmission type screen having a lenticular lens which is formed on a screen surface and is constituted by a plurality of lens units each having a lens portion at a top portion and total-reflection surfaces on two side surfaces, said lens portion of said lens unit of said lenticular lens being formed into a shape such that an aspherical lens surface is formed between a central portion and an outer edge portion, a convex lens surface is formed on the outer edge portion, and linear surfaces facing said total-reflection surfaces at the two side surfaces of said lens unit are formed on the central portion, said total-reflection surfaces at the two side surfaces being formed into arcuated surfaces capable of reflecting and focusing incident light from a back surface side of said screen toward said linear surfaces, and leading surfaces, which stand from said given plane of the screen body at an angle larger than that of said total-reflection surfaces, being formed at upper end sides of said total-reflection surfaces.

19. A projector apparatus comprising:

a case;

a transmission type screen provided on a predetermined surface of said case with its body being in a given plane to constitute a display window;

a display device arranged inside said case;

a projection lens means for enlarging and projecting an image displayed on said display device onto said transmission type screen; and

at least one mirror means for reflecting the image projected through said projection lens toward said transmission type screen,

said transmission type screen having a lenticular lens which is formed on a screen surface and is constituted by a plurality of lens units each having a lens portion at a top portion and total-reflection surfaces on two side surfaces, said lens portion of said lens unit of said lenticular lens being formed into a shape such that an aspherical lens surface is formed between a central portion and an outer edge portion having an outer edge side, a convex lens surface and a flat surface, extending substantially parallel to said given plane from said convex lens surface toward the outer edge side, are formed on the outer edge portion, and linear surfaces, facing said total-reflection surfaces at the two side surfaces of said lens unit, are formed on the central portion, said total-reflection surfaces at the two side surfaces being formed into arcuated surfaces capable of reflecting and focusing incident light from a back surface side of said screen toward said linear surfaces, and leading surfaces, which stand almost perpendicular to the given plane, being formed at upper end sides of said total-reflection surfaces.