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-like spot and a trapezoid-like 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-like spot is compensated to form a rectangular spot after being reflected by the curved reflector, and the image light beam forming the trapezoid-like spot is compensated to form another rectangular spot after being reflected by the curved reflector.
1 Assignment
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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-like spot and a trapezoid-like 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-like spot is compensated to form a rectangular spot after being reflected by the curved reflector, and the image light beam forming the trapezoid-like 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 type spot and a second type 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 type spot is compensated to form a rectangular spot after being reflected by the curved reflector, and the image light beam forming the second type spot is compensated to form another rectangular spot after being reflected by the curved reflector; wherein the first type spot comprises a first butterfly-like reference point (a), a second butterfly-like reference point (b), a third butterfly-like reference point (c), a fourth butterfly-like reference point (d), a fifth butterfly-like reference point (e), a sixth butterfly-like reference point (f), a seventh butterfly-like reference point (g), an eighth butterfly-like reference point (h), a ninth butterfly-like reference point (i), a tenth butterfly-like reference point (j), a eleventh butterfly-like reference point (k), a twelfth butterfly-like reference point (m), and a thirteenth butterfly-like 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-like reference points after being imaged by the first lens group and the second lens group, wherein a relationship of the butterfly-like reference points and the image points satisfies at least one of a first condition and a second condition as follows; wherein the second type spot comprises a first trapezoid-like reference point (a′
), a second trapezoid-like reference point (b′
), a third trapezoid-like reference point (c′
), a fourth trapezoid-like reference point (d′
), a fifth trapezoid-like reference point (e′
), a sixth trapezoid-like reference point (f′
), a seventh trapezoid-like reference point (g′
), an eighth trapezoid-like reference point (h′
), and a ninth trapezoid-like reference point (i′
), and the first image point (A), the second image point (B), the third image point (C), the fourth image point (D), the fifth image point (E), the sixth image point (F), the seventh image point (G), the eighth image point (H), and the ninth image point (I) on the light valve respectively form the trapezoid-like reference points after being imaged by the first lens group and the second lens group, wherein a relationship of the trapezoid-like reference points and the image points satisfies a third 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