Projection lens including first lens group and second lens group and projection device including planar reflector
First Claim
1. A projection lens, comprising:
- a first lens group, comprising a first spherical lens and a first aspheric lens, wherein an image beam is formed by a light valve passes through the first lens group to form an intermediate image with a first tangential field curvature; and
a second lens group, comprising a second spherical lens, a second aspheric lens, a third aspheric lens, a fourth aspheric lens and a twelfth spherical lens;
wherein refractive-powers of the third aspheric lens, the fourth aspheric lens, the second spherical lens, the twelfth spherical lens and the second aspheric lens are sequentially negative, positive, positive, negative and negative,wherein the first lens group is located between the light valve and the second lens group, and a lens in the first lens group closest to the second lens group is the first aspheric lens and the intermediate image is formed between the first aspheric lens and the second lens group, wherein the intermediate image with the first tangential field curvature passes through the second lens group to produce a second tangential field curvature, and one of the first tangential field curvature and the second tangential field curvature is a positive tangential field curvature while the other one is a negative tangential field curvature.
1 Assignment
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Accused Products
Abstract
A projection lens provided is for projecting an image beam. The projection lens is disposed on a transmission path of the image beam and includes a first group of lenses and a second group of lenses. The first group of lenses includes a first spherical lens and a first aspheric lens. After the image beam passes through the first group of lenses, an intermediate image is formed between the first group of lenses and the second group of lenses, in which the first aspheric lens is the lens in the first group of lenses closest to the second group of lenses. A projection device using the projection lens is also provided. The projection device further includes a planar reflector on the transmission path of the image beam.
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Citations
24 Claims
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1. A projection lens, comprising:
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a first lens group, comprising a first spherical lens and a first aspheric lens, wherein an image beam is formed by a light valve passes through the first lens group to form an intermediate image with a first tangential field curvature; and a second lens group, comprising a second spherical lens, a second aspheric lens, a third aspheric lens, a fourth aspheric lens and a twelfth spherical lens; wherein refractive-powers of the third aspheric lens, the fourth aspheric lens, the second spherical lens, the twelfth spherical lens and the second aspheric lens are sequentially negative, positive, positive, negative and negative, wherein the first lens group is located between the light valve and the second lens group, and a lens in the first lens group closest to the second lens group is the first aspheric lens and the intermediate image is formed between the first aspheric lens and the second lens group, wherein the intermediate image with the first tangential field curvature passes through the second lens group to produce a second tangential field curvature, and one of the first tangential field curvature and the second tangential field curvature is a positive tangential field curvature while the other one is a negative tangential field curvature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A projection device, comprising:
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an illumination unit, capable of providing an illumination beam; a light valve, disposed on transmission path of the illumination beam to convert the illumination beam into an image beam; and a projection lens, disposed on a transmission path of the image beam and comprising; a first lens group, comprising a first spherical lens and a first aspheric lens, wherein the image beam passes through the first lens group to form an intermediate image with a first tangential field curvature; a second lens group, comprising a second spherical lens, a second aspheric lens, a third aspheric lens, a fourth aspheric lens and a twelfth spherical lens;
wherein refractive-powers of the third aspheric lens, the fourth aspheric lens, the second spherical lens, the twelfth spherical lens and the second aspheric lens are sequentially negative, positive, positive, negative and negative, wherein the first lens group is located between the light valve and the second lens group, a lens in the first lens group closest to the second lens group is the first aspheric lens and the intermediate image is formed between the first aspheric lens and the second lens group, wherein the intermediate image with the first tangential field curvature passes through the second lens group to produce a second tangential field curvature, and one of the first tangential field curvature and the second tangential field curvature is a positive tangential field curvature while the other one is a negative tangential field curvature; anda planar reflector, disposed on the transmission path of the image beam, wherein the second lens group is located between the first lens group and the planar reflector, and the planar reflector is configured for reflecting the image beam from the second lens group. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification