Fixed-focus lens
First Claim
1. A fixed-focus lens, adapted to be disposed between a primary image side and a second image side and having an optical axis, the fixed-focus lens comprising:
- a first lens group disposed between the primary image side and the second image side and comprising an aspheric lens;
a second lens group disposed in a light path between the primary image side and the first lens group and comprising a first lens, a second lens, and a third lens sequentially arranged from the primary image side to the second image side, wherein refractive powers of the first lens and the third lens are both positive, and each of the first lens, the second lens, and the third lens is a spherical lens; and
a curved reflector disposed in a light path between the primary image side and the second image side, wherein a refractive power of the curved reflector is negative;
wherein an image light beam transmitted from the primary image side and passing through the first lens group and the second lens group forms one of a butterfly spot and a trapezoid spot on a reference plane, and the reference plane is located between the first lens group and the curved reflector and perpendicular to a part of the optical axis between the first lens group and the curved reflector;
wherein the image light beam forming the butterfly spot is compensated to form a rectangular spot after being reflected by the curved reflector, and the image light beam forming the trapezoid spot is compensated to form another rectangular spot after being reflected by the curved reflector.
1 Assignment
0 Petitions
Accused Products
Abstract
A fixed-focus lens adapted to be disposed between a primary image side and a second image side is provided. The fixed-focus lens includes a second lens group, a first lens group, and a curved reflector arranged in sequence from the primary image side to the second image side. The second lens group includes a first lens, a second lens, and a third lens arranged in sequence from the primary image side to the second image side. The first lens and the third lens have positive refractive powers and each of the first lens, the second lens, and the third lens is a spherical lens.
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Citations
21 Claims
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1. A fixed-focus lens, adapted to be disposed between a primary image side and a second image side and having an optical axis, the fixed-focus lens comprising:
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a first lens group disposed between the primary image side and the second image side and comprising an aspheric lens; a second lens group disposed in a light path between the primary image side and the first lens group and comprising a first lens, a second lens, and a third lens sequentially arranged from the primary image side to the second image side, wherein refractive powers of the first lens and the third lens are both positive, and each of the first lens, the second lens, and the third lens is a spherical lens; and a curved reflector disposed in a light path between the primary image side and the second image side, wherein a refractive power of the curved reflector is negative; wherein an image light beam transmitted from the primary image side and passing through the first lens group and the second lens group forms one of a butterfly spot and a trapezoid spot on a reference plane, and the reference plane is located between the first lens group and the curved reflector and perpendicular to a part of the optical axis between the first lens group and the curved reflector; wherein the image light beam forming the butterfly spot is compensated to form a rectangular spot after being reflected by the curved reflector, and the image light beam forming the trapezoid spot is compensated to form another rectangular spot after being reflected by the curved reflector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A fixed-focus lens, adapted to be disposed between a primary image side and a second image side and having an optical axis, wherein a light valve is adapted to be disposed at the primary image side and capable of emitting an image light beam, the fixed-focus lens comprising:
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a first lens group disposed between the primary image side and the second image side and comprising an aspheric lens; a second lens group disposed in a light path between the primary image side and the first lens group and comprising a first lens, a second lens, and a third lens sequentially arranged from the primary image side to the second image side, wherein refractive powers of the first lens and the third lens are both positive, and each of the first lens, the second lens, and the third lens is a spherical lens; and a curved reflector disposed in a light path between the primary image side and the second image side, wherein a refractive power of the curved reflector is negative; wherein the image light beam passing through the first lens group and the second lens group forms one of a first spot and a second spot on a reference plane, and the reference plane is located between the first lens group and the curved reflector and perpendicular to a part of the optical axis between the first lens group and the curved reflector; wherein the image light beam forming the first spot is compensated to form a rectangular spot after being reflected by the curved reflector, and the image light beam forming the second spot is compensated to form another rectangular spot after being reflected by the curved reflector; wherein the first spot comprises a first butterfly reference point (a), a second butterfly reference point (b), a third butterfly reference point (c), a fourth butterfly reference point (d), a fifth butterfly reference point (e), a sixth butterfly reference point (f), a seventh butterfly reference point (g), an eighth butterfly reference point (h), a ninth butterfly reference point (i), a tenth butterfly reference point (j), a eleventh butterfly reference point (k), a twelfth butterfly reference point (m), and a thirteenth butterfly reference point (n), and a first image point (A), a second image point (B), a third image point (C), a fourth image point (D), a fifth image point (E), a sixth image point (F), a seventh image point (G), an eighth image point (H), a ninth image point (I), a tenth image point (J), a eleventh image point (K), a twelfth image point (M), and a thirteenth image point (N) on the light valve respectively form the butterfly reference points after being imaged by the first lens group and the second lens group, wherein a relationship of the butterfly reference points and the image points satisfies at least one of a first condition and a second condition as follows;
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21. A fixed-focus lens, adapted to be disposed between a primary image side and a second image side and having an optical axis, the fixed-focus lens comprising:
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a first lens group disposed between the primary image side and the second image side and comprising an aspheric lens; a second lens group disposed in a light path between the primary image side and the first lens group and comprising a first lens, a second lens, and a third lens sequentially arranged from the primary image side to the second image side, wherein refractive powers of the first lens and the third lens are both positive, and each of the first lens, the second lens, and the third lens is a spherical lens; and a curved reflector disposed in a light path between the primary image side and the second image side, wherein a refractive power of the curved reflector is negative; wherein an effective focal length (EFL) of the fixed-focus lens is F, an EFL of the first lens group is F1, and an EFL of the second lens group is F2, and the fixed-focus lens satisfies at least one of following conditions;
8.5<
|F1/F|<
50.1 and 20.2<
|F2/F|<
75.7.
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Specification