Projection-type picture display apparatus and screen used thereby

A screen for allowing light generated by a light source and modulated by a picture display device having pixels extending in a vertical and in a horizontal direction and laid out to form a matrix to produce an image thereon to be projected on said screen as an enlarged picture, said screen comprising:

• a Fresnel lens sheet forming Fresnel lenses at an emission side of said light;
• a first member disposed for receiving light emitted from said Fresnel lens sheet and having light passing units formed at a light emission side of said first member, and a plurality of light absorbing portions, one of the light absorbing portions being provided between said light passing units;
• and
• a second member placed on said emission side of said first member and adhered to said first member;
• wherein a pitch in the vertical direction of the pixels projected and enlarged on said screen from said image produced by said picture display device is at least twice of a pitch of said Fresnel lenses formed on said Fresnel lens sheet;
• and
• wherein a pitch Mp1 of moire fringes, which are generated due to interference between said light absorbing portions and said Fresnel lenses, is less than to a pixel pitch Iph in the horizontal direction.

A screen, on which a display picture of an image display element, on which pixels are aligned in a matrix manner, is projected enlargedly, comprising:

• a first sheet on which Fresnel lenses are formed at a picture observation side;
• a second sheet being disposed at the picture observation side of said first sheet;
• and
• a third sheet being disposed at a picture observation side of said second sheet, said third sheet being one of adhered and bonded upon a picture observation side surface of said second sheet;
• wherein, on the picture observation side of said second sheet opening portions for emitting light therethrough are disposed, said opening portions being formed so as to extend in a direction perpendicular to said screen, and light absorbing portions are alternately disposed in a horizontal direction of said screen;
• wherein the following condition is satisfied:
• Ipv/Fp≧2,
• where a pixel pitch of said image display element in a vertical direction is Ipv, which is projected upon said screen enlargedly, and a pitch of the Fresnel lenses which are formed on said first sheet is Fp;
• and
• wherein a ratio (Lp/Fp) between a pitch Lp of said light absorbing portions and the pitch Fp of said Fresnel lenses satisfies the following condition:
• 1.558≦Lp/Fp≦1.649.

A screen, on which a display picture of an image display element, on which pixels are aligned in a matrix manner, is projected enlargedly, comprising:

• a first sheet on which Fresnel lenses are formed at a picture observation side;
• a second sheet being disposed at the picture observation side of said first sheet;
• and
• a third sheet being disposed at a picture observation side of said second sheet, said third sheet being one of adhered and bonded upon a picture observation side surface of said second sheet;
• wherein, on the picture observation side of said second sheet opening portions for emitting light therethrough are disposed, said opening portions being formed so as to extend in a direction perpendicular to said screen, and light absorbing portions are alternately disposed in a horizontal direction of said screen;
• wherein the following condition is satisfied:
• Ipv/Fp≧2,
• where a pixel pitch of said image display element in a vertical direction is Ipv, which is projected upon said screen enlargedly, and a pitch of the Fresnel lenses which are formed on said first sheet is Fp;
• and
• wherein the following further condition is satisfied:
• Mp1<Iph,
• where a pitch of moire fringes, which are generated due to interference between said light absorbing portions and said Fresnel lenses, is Mp1, and a pixel pitch of said image display element in a horizontal direction if 1ph.

A screen, on which a display picture of an image display element, on which pixels are aligned in a matrix manner, is projected enlargedly, comprising:

• a first sheet on which Fresnel lenses are formed at a picture observation side;
• a second sheet being disposed at the picture observation side of said first sheet;
• and
• a third sheet being disposed at a picture observation side of said second sheet, said third sheet being one of adhered and bonded upon a picture observation side surface of said second sheet;
• wherein said third sheet includes a light scattering material for scattering the light;
• wherein, on the picture observation side of said second sheet, opening portions for emitting the light therethrough are disposed, said opening portions being formed so as to extend in a perpendicular direction of said screen, and light absorbing portions are alternately disposed in a horizontal direction of said screen;
• and
• wherein a pixel pitch of said image display element in a perpendicular direction, which is projected upon said screen enlargedly, is at least equal to twice of a pitch of said Fresnel lenses which are formed on said first sheet, and a ratio (Lp/Fp) between a pitch Lp of said light absorbing portions and a pitch Fp of said Fresnel lenses is within a range of 1.558 to 1.649.