COMPACT PROJECTION LENSES FOR USE WITH LARGE FORMAT PIXELIZED PANELS
First Claim
1. A projection lens for forming an enlarged image of a pixelized panel on a screen, said projection lens having a long conjugate side, a short conjugate side, and an effective focal length f0, said lens, in order from the long conjugate side to the short conjugate side, comprising:
- (I) a first lens unit consisting in order from the long conjugate side to the short conjugate side of;
(A) a first lens sub-unit having a negative power and comprising a negative lens element which (i) has a short conjugate surface which is concave towards the short conjugate side and (ii) comprises at least one aspheric surface; and
(B) a second lens sub-unit;
(II) an aperture stop; and
(III) a second lens unit having a positive power, an effective focal length fU2, and consisting in order from the long conjugate side to the short conjugate side of;
(A) a first lens sub-unit having a positive power, an effective focal length fU2S1 and comprising a positive lens element and a negative lens element, the positive lens element having a lower dispersion than the negative lens element; and
(B) a second lens sub-unit which, in order from the long conjugate side to the short conjugate side, comprises;
a negative lens element having a focal length fneg and a lens element which comprises an aspherical surface which has a positive on-axis power;
or a lens element having first and second optical surfaces,—
where the first surface has a negative power φ
neg, the second surface is an aspherical surface which has a positive on-axis power, and the first and second surfaces are separated by an axial distance t which satisfies the relationship;
t/f0≧
0.05;
wherein;
(a) the first and second lens units are the only lens units of the projection lens;
(b) fU2/f0≦
1.5;
(c) fU2S1/f0≦
2.0; and
(d) |fneg|≦
2.0·
f0 or 1/|φ
neg|≦
1.5·
f0.
1 Assignment
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Accused Products
Abstract
Projection lenses for use with pixelized panels (PP) are provided. The projection lenses have first and second lens units (U1,U2), with the first lens unit having a negative or weakly positive power and the second lens unit having a positive power. The second lens unit has first and second subunits (U2S1 and U2S2) which provide positive power followed by negative power. The second subunit (U2S2) of the second unit (U2), in turn, has negative power followed by positive power. In this way, an overall short projection lens (e.g., BRL/f0≦0.9) along with small lens elements (e.g., CAmax/f0≦0.8) can be achieved.
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Citations
24 Claims
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1. A projection lens for forming an enlarged image of a pixelized panel on a screen, said projection lens having a long conjugate side, a short conjugate side, and an effective focal length f0, said lens, in order from the long conjugate side to the short conjugate side, comprising:
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(I) a first lens unit consisting in order from the long conjugate side to the short conjugate side of;
(A) a first lens sub-unit having a negative power and comprising a negative lens element which (i) has a short conjugate surface which is concave towards the short conjugate side and (ii) comprises at least one aspheric surface; and
(B) a second lens sub-unit;
(II) an aperture stop; and
(III) a second lens unit having a positive power, an effective focal length fU2, and consisting in order from the long conjugate side to the short conjugate side of;
(A) a first lens sub-unit having a positive power, an effective focal length fU2S1 and comprising a positive lens element and a negative lens element, the positive lens element having a lower dispersion than the negative lens element; and
(B) a second lens sub-unit which, in order from the long conjugate side to the short conjugate side, comprises;
a negative lens element having a focal length fneg and a lens element which comprises an aspherical surface which has a positive on-axis power;
ora lens element having first and second optical surfaces,—
where the first surface has a negative power φ
neg, the second surface is an aspherical surface which has a positive on-axis power, and the first and second surfaces are separated by an axial distance t which satisfies the relationship;
t/f0≧
0.05;
wherein;
(a) the first and second lens units are the only lens units of the projection lens;
(b) fU2/f0≦
1.5;
(c) fU2S1/f0≦
2.0; and
(d) |fneg|≦
2.0·
f0 or 1/|φ
neg|≦
1.5·
f0. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A projection lens for forming an enlarged image of a pixelized panel on a screen, said projection lens having a long conjugate side, a short conjugate side, and an effective focal length f0, said lens, in order from the long conjugate side to the short conjugate side, comprising:
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(I) a first lens unit consisting in order from the long conjugate side to the short conjugate side of;
(A) a negative lens element which (i) has a short conjugate surface which is concave towards the short conjugate side and (ii) comprises at least one aspheric surface; and
(B) a positive lens element;
(II) an aperture stop; and
(III) a second lens unit having a positive power, an effective focal length fU2, and consisting in order from the long conjugate side to the short conjugate side of;
(A) a first lens sub-unit having a positive power, an effective focal length fU2S1 and consisting in order from the long conjugate side to the short conjugate side of a positive lens element and a negative lens element which form a cemented doublet, the positive lens element having a lower dispersion than the negative lens element; and
(B) a second lens sub-unit which, in order from the long conjugate side to the short conjugate side, consists of;
a negative lens element having a focal length fneg and a lens element which comprises an aspherical surface which has a positive on-axis power;
ora lens element having first and second optical surfaces, where the first surface has a negative power φ
neg, the second surface is an aspherical surface which has a positive on-axis power, and the first and second surfaces are separated by an axial distance t which satisfies the relationship;
t/f0≧
0.05;
wherein;
(a) the first and second lens units are the only lens units of the projection lens;
(b) fU2/f0≦
1.5;
(c) fU2S1/f0≦
2.0; and
(d) |fneg|≦
2.0·
f0 or 1/φ
neg|≦
1.5·
f0. - View Dependent Claims (22, 23, 24)
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Specification