Projection-type picture display apparatus and screen used thereby
AssigneeHitachi, Ltd.
InventorsKoji Hirata, Shigeru Inaoka
Life of this patent
Estimating the term…
Abstract
A screen for use in a projection-type image display apparatus having an image displaying element which includes a plurality of pixels for modulating light from a light source so as to form an enlarged picture on the screen. The screen includes a Fresnel lens sheet, a first sheet disposed on the light emission side of the Fresnel lens sheet, and a second sheet disposed on a light emission side of the first sheet. The first sheet includes a plurality of lenticular lenses which extend in a longitudinal direction and are arranged in a horizontal direction, with light passing window portions being formed at positions opposing the lenticular lenses and with light absorbing portions provided therebetween.
Claims3
A screen for use in a projection-type image display apparatus having an image displaying element which includes a plurality of pixels for modulating a light from a light source so as to form an image formed by said image displaying element to be projected on said screen as an enlarged picture, said screen comprising:
- a Fresnel lens sheet;
- a first sheet disposed on a light emission side of said Fresnel lens sheet;
- and
- a second sheet disposed on a light emission side of said first sheet;
- wherein said first sheet includes a plurality of lenticular lenses formed on a light incident side thereof, said lentiular lenses extending in a longitudinal direction and being arranged in a horizontal direction, light passing window portions formed at positions opposing to said lenticular lenses with light absorbing portions provided between said light passing window portions;
- wherein the following equations are satisfied:
- 1.558≦Lp/Fp≦1.649;
- Lp<Iph;
- and
- Ipv/Fp≧2;
- where Fp is a pitch between Fresnel lenses formed on said Fresnel lens sheet, Lp is a pitch of the light absorbing portions provided on said first sheet, Iph is a pixel pitch of said image display element which is projected so as to form an enlarged picture on said screen in a horizontal direction, and Ipv is a pixel pitch thereof in a vertical direction.
A screen for use in a projection-type image display apparatus having an image displaying element, which includes a plurality of pixels for modulating a light from a light source so as to form an image formed by said image displaying element to be projected on said screen as an enlarged picture, said screen comprising:
- a Fresnel sheet;
- and
- another sheet which is disposed on a light emission side of said Fresnel lens sheet and has lenticular lenses which are formed on a light incident side thereof so as to extend in a longitudinal direction and being arranged in a horizontal direction;
- wherein said second sheet includes light passing window portions formed at positions opposing to said lenticular lenses with light absorbing portions being provided therebetween;
- wherein following equations are satisfied;
- 1.558≦Lp/Fp≦1.649;
- Lp<Iph;
- and
- Ipv/Fp≧2;
- where Fp is a pitch between Fresnel lenses formed on said Fresnel sheet, Lp is a pitch of the light absorbing portion provided on said another sheet, Iph is a pixel pitch of said image display element which is projected so as to form an enlarged picture on said screen in a horizontal direction, and Ipv is a pixel pitch thereof in a vertical direction.
A lenticular lens sheet for use in a screen for displaying an enlarged and projected display image from an image display device having pixels laid out in a matrix form, the screen including a Fresnel lens sheet having Fresnel lenses, the lenticular lens sheet comprising:
- a plurality of lenticular lenses which are arranged in a horizontal direction of the screen, the lenticular lenses extending in vertical direction of the screen;
- a plurality of light passing portions which are provided at positions opposed to each of the lenticular lenses;
- and
- a plurality of light absorbing portions, one of the light absorbing portions being provided between the light passing portions;
- wherein the light absorbing portions are arranged so that the following equations are satisfied
- 1.558≦Lp/Fp<1.649;
- and
- Lp<Iph;
- wherein Fp is a pitch between the Fresnel lenses formed on the Fresnel lens sheet, Lp is a pitch of the light absorbing portions provided on the lenticular lens sheet, and Iph is an enlarged and projected pixel pitch of the image display device on the screen in a horizontal direction.
Dependencies are inferred from the claim text.