Rear-projection screen and a rear projection image display employing the rear-projection screen

A lenticular lens sheet for a rear-projection screen, said lenticular lens sheet comprising an entrance surface formed by contiguously and horizontally arranging a plurality of first vertically elongate lenticular lenses, and an exit surface formed by horizontally arranging a plurality of second vertically elongate lenticular lenses substantially opposite to the first vertically elongate lenticular lenses, respectively, and horizontally arranging a plurality of vertically elongate light absorbing strips of a finite width on vertically elongate light absorbing strips of a finite width on boundaries between the adjacent second vertically elongate lenticular lenses, respectively;

• wherein each of said first vertically elongate lenticular lenses having a convex, horizontal cross section symmetrical with respect to an optical axis thereof, and a sign of a derivative of an equation Z=f(r), where r is the distance between a point on the convex contour of the convex, horizontal cross section and the optical axis and Z is the distance in a parallel direction to the optical axis between the same point on the convex contour and the vertex of the convex, horizontal cross section, defining the convex contour of the convex, horizontal cross section for a point on the convex contour near the optical axis and the sign of a second derivative of the equation Z=f(r) for a point on the convex contour remote from the optical axis being different from each other.

A rear-projection screen for a rear-projection image display having a video source, comprising:

• a Fresnel lens sheet disposed on a side of the video source;
• and
• a lenticular lens sheet disposed on a viewing side of the video source,
• wherein the Fresnel lens sheet having an entrance surface formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses, and an exit surface having a shape of a convex Fresnel lens, and the lenticular lens sheet having an entrance surface formed by contiguously and horizontally arranging a plurality of first vertically elongate lenticular lenses, and
• wherein a refracting power of a first portion of each of said first vertically elongate lenticular lenses, remote from an optical axis of said first vertically elongate lens, is smaller than that of a second portion of each of said first vertically elongate lenticular lenses around the optical axis.

A rear-projection screen for a rear-projection image display having a video source, comprising:

• a Fresnel lens sheet disposed on a side of the video source;
• and
• a lenticular lens sheet disposed on a viewing side of the video source,
• wherein the Fresnel lens having an entrance surface formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses, and an exit surface having a shape of a convex Fresnel lens, and the lenticular lens sheet having an entrance surface formed by contiguously and horizontally arranging a plurality of first vertically elongate lenticular lenses,
• wherein each of said first vertically elongate lenticular lenses having a convex, horizontal cross section convex toward the video source and symmetrical with respect to an optical axis thereof, and
• wherein the sign of a second derivative of an equation Z=f(r), where r is a distance between a point on a convex contour of a convex, horizontal cross section and the optical axis and Z is a distance in a parallel direction to the optical axis between a same point on the convex contour and a vertex of a convex, horizontal cross section, defining the convex contour of the convex, horizontal cross section for a point on the convex contour near the optical axis and the sign of the second derivative of the equation Z=f(r) for a point on the convex contour remote from the optical axis are different from each other.

A rear-projection screen for a rear-projection image display having a video source, comprising:

• a Fresnel lens sheet disposed on a side of the video source;
• and
• a lenticular lens sheet disposed on a viewing side of the video source,
• wherein the Fresnel lens sheet having an entrance surface formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses, and an exit surface having a shape of a convex Fresnel lens, and the lenticular lens sheet having an entrance surface formed by contiguously and horizontally arranging a plurality of first vertically elongate lenticular lenses, and an exit surface formed by horizontally arranging a plurality of second vertically elongate lenticular lenses substantially opposite to the first vertically elongate lenticular lenses, respectively, and horizontally arranging a plurality of vertically elongate light absorbing strips of a finite width on boundaries between adjacent ones of the second vertically elongate lenticular lenses, respectively,
• wherein each of said second vertically elongate lenticular lenses having a convex, horizontal cross section convex toward the viewing side and symmetrical with respect to an optical axis thereof, and
• wherein a sign of a second derivative of an equation Z=f(r), where r is a distance between a first point on the convex contour of the convex, horizontal cross section and the optical axis and Z is a distance in a parallel direction to the optical axis between the first point on the convex contour and a vertex of the convex, horizontal cross section, defining the convex contour of the convex, horizontal cross section for a point on the convex contour near the optical axis and a sign of the second derivative of the equation Z=f(r) for a second point on the convex contour remote from the optical axis are different from each other.