LCD projection lens
First Claim
Patent Images
1. A projection lens for forming a magnified image of an object, said lens having an aperture stop, a short conjugate, and a long conjugate, said lens comprising:
- (a) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; and
(b) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where;
(i) f3 >
0;
(ii) f3 <
|f1 |;
(iii) f3 <
|f2 |;
(iv) the projection lens has an object side associated with the short conjugate and an image side associated with the long conjugate; and
(v) the two meniscus elements are on the object side of the projection lens and the color-correcting doublet is on the image side of the projection lens.
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Accused Products
Abstract
A projection lens for use with LCD panels is provided. The lens has two aspherical meniscus elements which are concave to each other and are located in the vicinity of the lens'"'"' aperture stop and a color-correcting doublet which provides most of the positive optical power of the lens. The lens can also include an aspherical corrector lens element of weak optical power which is located on the side of the two meniscus elements opposite to the color correcting doublet.
98 Citations
17 Claims
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1. A projection lens for forming a magnified image of an object, said lens having an aperture stop, a short conjugate, and a long conjugate, said lens comprising:
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(a) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; and (b) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where; (i) f3 >
0;(ii) f3 <
|f1 |;(iii) f3 <
|f2 |;(iv) the projection lens has an object side associated with the short conjugate and an image side associated with the long conjugate; and (v) the two meniscus elements are on the object side of the projection lens and the color-correcting doublet is on the image side of the projection lens. - View Dependent Claims (7, 8, 9, 10, 13, 14, 15, 16, 17)
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2. A projection lens for forming an image of an object, said lens having an aperture stop and consisting of:
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(a) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; and (b) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where; f3 >
0;f3 <
|f1 |; andf3 <
|f2 |. - View Dependent Claims (11, 12)
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3. A projection lens for forming an image of an object, said lens having an aperture stop and consisting of:
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(a) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; (b) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where; f3 >
0;f3 <
|f1 |;f3 <
|f2 |; and(c) a corrector lens element which has at least one aspherical surface and is of weak optical power; said color correcting doublet and said corrector lens element being on opposite sides of said two meniscus elements.
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4. A projection lens system for forming a magnified image of an object, said system comprising:
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(a) an illumination system comprising a light source and illumination optics which forms an image of the light source, said image of the light source being the output of the illumination system; (b) a pixelized panel which comprises the object; and (c) a projection lens having an aperture stop, a short conjugate, and a long conjugate, said lens comprising; (A) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; and (B) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where; (i) f3 >
0;(ii) f3 <
|f1 |;(iii) f3 <
|f2 |;(iv) the projection lens has an object side associated with the short conjugate and an image side associated with the long conjugate; and (v) the two meniscus elements are on the object side of the projection lens and the color-correcting doublet is on the image side of the projection lens.
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5. A projection lens system for forming an image of an object, said system comprising:
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(a) an illumination system comprising a light source and illumination optics which forms an image of the light source, said image of the light source being the output of the illumination system; (b) a pixelized panel which comprises the object; and (c) a projection lens having an aperture stop and consisting of; (A) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; and (B) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where; f3 >
0;f3 <
|f1 |; andf3 <
|f2 |.
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6. A projection lens system for forming an image of an object, said system comprising:
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(a) an illumination system comprising a light source and illumination optics which forms an image of the light source, said image of the light source being the output of the illumination system; (b) a pixelized panel which comprises the object; and (c) a projection lens having an aperture stop and consisting of; (A) two meniscus elements having focal lengths f1 and f2, said meniscus elements being (i) concave to each other and (ii) located in the vicinity of the aperture stop, each meniscus element having at least one aspherical surface; (B) a color-correcting doublet having a focal length f3 and comprising a positive crown element and a negative flint element, where; f3 >
0;f3 <
|f1 |;f3 <
|f2 |; and(C) a corrector lens element which has at least one aspherical surface and is of weak optical power; said color correcting doublet and said corrector lens element being on opposite sides of said two meniscus elements.
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Specification