Transmission screen and projection display

1. A transmission screen comprising:

Fresnel lens means having a Fresnel surface molded as an incident plane thereof for giving its optical action to projected light fluxes, and for outputting the light fluxes through an outgoing plane thereof;

stray light eliminating means for eliminating an ineffective light flux generated based on the optical action of the Fresnel surface; and

image display means for focusing the light flux from the stray light eliminating means and controlling the light flux distribution characteristic.

2. The transmission screen according to claim 1 , wherein the Fresnel lens means is refraction Fresnel lens means having a refraction Fresnel plane formed at the incident plane thereof, and

the refraction Fresnel plane comprises: refraction inclined planes for refracting light fluxes; and ineffective facet planes, which are arranged in a periodic structure.

3. The transmission screen according to claim 1 , wherein the Fresnel lens means is total reflection Fresnel lens means having a total reflection Fresnel plane formed at the incident plane thereof, and

the total reflection Fresnel plane comprises: transmission inclined planes for refracting light fluxes; and total reflection inclined planes for reflecting the light fluxes refracted at the transmission inclined planes, which are arranged in a periodic structure.

4. The transmission screen according to claim 1 , wherein the Fresnel lens means is refraction total reflection Fresnel lens means having a refraction total reflection Fresnel plane formed at the incident plane thereof, and

the refraction total reflection Fresnel plane comprises: refraction inclined planes for refracting light fluxes; ineffective facet planes; transmission inclined planes for refracting the light fluxes; and total reflection inclined planes for reflecting the light fluxes refracted at the transmission inclined planes, which are arranged in a periodic structure.

5. The transmission screen according to claim 2 , wherein the refraction inclined planes in the Fresnel lens means refract the projected light fluxes toward a direction approximately parallel to a normal of the outgoing plane of the Fresnel lens means.

6. The transmission screen according to claim 3 , wherein the total reflection inclined planes in the Fresnel lens means reflect the light fluxes refracted at the transmission inclined planes toward a direction approximately parallel to a normal of the outgoing plane of the Fresnel lens means.

7. The transmission screen according to claim 4 , wherein the refraction inclined planes in the Fresnel lens means refract the projected light fluxes toward a direction approximately parallel to a normal of the outgoing plane of the Fresnel lens means, and

the total reflection inclined planes in the Fresnel lens means reflect the light fluxes refracted at the transmission inclined planes toward the direction approximately parallel to the normal of the outgoing plane of the Fresnel lens means.

8. The transmission screen according to claim 4 , wherein the Fresnel lens means changes a ratio of a total reflection Fresnel section and a refraction Fresnel section, and the total reflection Fresnel section is composed of the transmission inclined planes and the total reflection inclined planes and the refraction Fresnel section is composed of the refraction inclined planes and the ineffective facet planes according to a distance measured from a center of its rotation.

9. The transmission screen according to claim 1 , wherein the stray light eliminating means comprises: condensing light lens array means in which unit lenses are arranged at an incident plane of a first transmission substrate in a periodic structure in an up-and-down direction; and first black stripe means

composed of transparent sections placed near a condensing light point of each unit lens and opaque sections placed at a peripheral area of the condensing light point of each unit lens, which are arranged alternately at the outgoing plane of the first transparent substrate in a periodic structure in an up-and-down direction.

10. The transmission screen according to claim 1 , wherein the image display means is lenticular lens means having the unit lenses arranged in a periodic structure in a horizontal direction at an incident plane of a second transparent substrate having a scattering characteristic capable of scattering the light fluxes.

11. The transmission screen according to claim 9 , wherein the stray light eliminating means comprises: a holding transmission substrate for holding the first transmission substrate; the condensing light lens array means; and the first black stripe means.

12. The transmission screen according to claim 9 , wherein the stray light eliminating means comprises: the condensing light lens array means; and the first black stripe means, which are molded with a concentric circle shape around a center of rotation of the Fresnel lens means.

13. The transmission screen according to claim 9 , wherein the stray light eliminating means comprises: the condensing light lens array means; and the first black stripe means, which are molded with a periodic structure of a line shape.

14. The transmission screen according to claim 9 , wherein the stray light eliminating means comprises: one of the first transmission substrate having a scattering characteristic; and the condensing light lens array means having the scattering characteristic.

15. The transmission screen according to claim 10 , wherein the image display means comprises: second black stripe means in which transparent sections and opaque sections are arranged at the outgoing plane of a third transparent substrate alternately in a periodic structure in a horizontal direction, the transparent sections are placed near the condensing light point of each unit lens in the lenticular lens means, and the opaque sections are placed at a peripheral area of the condensing light point of each unit lens.

16. The transmission screen according to claim 1 , wherein the stray light eliminating means comprises:

transparent sections through which the light fluxes pass;

horizontal louver shaped opaque sections arranged in a periodic structure in an up-and-down direction between the transparent sections; and

up-and-down louver shaped opaque sections arranged in a periodic structure in a horizontal direction between the transparent sections.

17. The transmission screen according to claim 10 , wherein the stray light eliminating means comprises:

transparent sections through which the light fluxes pass; and

a horizontal louver shaped opaque sections arranged in a periodic structure in an up-and-down direction between the transparent sections,

and the image display means comprises second black stripe means in which transparent sections and opaque sections are arranged at the outgoing plane of a third transparent substrate alternately in a periodic structure in a horizontal direction, the transparent sections are placed near the condensing light point of each unit lens in the lenticular lens means, and the opaque sections are placed at a peripheral area of the condensing light point of each unit lens.

18. The transmission screen according to claim 16 , wherein the louver shaped opaque section in the stray light eliminating means has a cross section so that a width of the louver shaped opaque section is changed along the direction of the normal of the outgoing plane of the Fresnel lens means.

19. The transmission screen according to claim 17 , wherein the louver shaped opaque section in the stray light eliminating means has a cross section so that a width of the louver shaped opaque section is changed along the direction of the normal of the outgoing plane of the Fresnel lens means.

20. A projection display device comprising: a transmission screen; and a projection optical system for projecting light fluxes to the transmission screen in order to focus an image on the transmission screen,

wherein the transmission screen comprises:

Fresnel lens means having a Fresnel surface molded at an incident plane thereof for giving its optical action to projected light fluxes and for outputting the light fluxes through its outgoing plane;

stray light eliminating means for eliminating an ineffective light flux generated based on the optical action of the Fresnel surface; and

image display means for focusing the light flux from the stray light eliminating means and controlling the light flux distribution characteristic.

21. A light transmission apparatus, comprising:

a Fresnel lens having a Fresnel surface as an incident plane thereof, and directing an incoming light flux;

a stray light eliminating plate which receives a light flux from the Fresnel lens, wherein the stray light eliminating plate eliminates a vertical component of ineffective light flux, and further comprises,

a condensing light lens array periodic in a vertical direction which focuses the light flux received from the Fresnel lens,

a transmission substrate which receives the focused light flux from the condensing light array, and

a plurality of black stripes associated with the outgoing side of the transmission substrate which are arranged to block the vertical component of ineffective light flux; and

an image display plate which receives a light flux from the stray light eliminating plate, wherein the image display plate eliminates a horizontal component of ineffective light flux.

22. A light transmission apparatus, comprising:

a Fresnel lens having a Fresnel surface as an incident plane thereof, and directing an incoming light flux;

a stray light eliminating plate which receives a light flux from the Fresnel lens, wherein the stray light eliminating plate eliminates a vertical component of ineffective light flux; and

an image display plate which receives a light flux from the stray light eliminating plate, wherein the image display plate eliminates a horizontal component of ineffective light flux and further comprises

a condensing light lens array periodic in the horizontal direction which focuses the light flux received from the stray light eliminating plate,

a first transmission substrate which receives the focused light flux from the condensing light lens array,

a plurality of black stripes associated with the outgoing side of the first transmission substrate which are arranged to block the horizontal component of ineffective light by opaque sections, and

a second transmission substrate which receives light flux through transparent sections of the plurality of black stripes.