Wide field of view projection lenses for compact projection lens systems employing pixelized panels
AssigneeCorning Precision Lens
InventorJacob Moskovich
Life of this patent
Estimating the term…
Abstract
A projection lens for use with LCD panels is provided. The lens has a first lens unit which includes a strong negative lens element having an aspherical surface which provides distortion correction, and a second lens unit which includes a first lens subunit separated by an airspace from a second lens subunit, wherein the first lens subunit has a strong positive power and the second lens subunit has a weaker power. The second lens subunit can include a negative lens element, followed by a positive lens element, followed by a plastic lens element having an aspherical surface. The projection lens has a field of view of at least 35° so that the overall projection lens system has a compact size.
Claims16
A projection lens for forming an image of an object, said projection lens having a focal length f0 and consisting in order from its image side of:
- (A) a first lens unit having a focal length f1 and comprising:
- (i) a lens element having a focal length fE1;
- and
- (ii) at least one aspherical surface for correction of distortion;
- and
- (B) a second lens unit having a focal length f2 and consisting in order from its image side of:
- (i) a first lens subunit having a focal length f2S1;
- and
- (ii) a second lens subunit separated from the first lens subunit by an airspace and having a focal length f2S2, said second lens subunit comprising:
- (a) at least one aspherical surface for correction of spherical aberration, and (b) means for providing axial color correction for the lens system;
- wherein:
- |f1|/f0 > 0.75;
- fE1 < 0;
- f2 > 0;
- f2/f0 < 2.0 f2S1 > 0;
- f2S1/f0 < 1.5;
- and |f2S2|/f0 > 1.5.
A projection lens for forming an image of an object, said projection lens having a focal length f0 and consisting in order from its image side of:
- (A) a first lens unit having a focal length f1 and comprising:
- (i) a lens element having a focal length fE1;
- and
- (ii) at least one aspherical surface for correction of distortion;
- and
- (B) a second lens unit having a focal length f2 and consisting in order from its image side of:
- (i) a first lens subunit having a focal length f2S1;
- and
- (ii) a second lens subunit separated from the first lens subunit by an airspace and having a focal length f2S2, said second lens subunit consisting in order from its image side of:
- (a) a negative lens element, (b) a positive lens element, and (c) a plastic lens element having at least one aspherical surface;
- wherein:
- |f1|/f0 > 0.75;
- fE1 < 0;
- f2 > 0;
- f2/f0 < 2.0;
- f2S1 > 0;
- f2S1/f0 < 1.5;
- and |f2S2|/f0 > 1.5.
Dependencies are inferred from the claim text.