Projection lens and projection device using the same
AssigneeQisda Corporation
InventorMing-Kuen Lin
Life of this patent
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Abstract
A projection lens and a projection device using the same are provided. The projection device comprises a projection lens and an optical element. The projection lens comprises a first lens group and a second lens group from an image side sequentially. The first lens group has a negative refracting power, and the first lens group includes an aspherical lens surface. The second lens group has a positive refracting power. The first lens group has a first focal length f1, and the second lens group has a second focal length f2. The first focal length f1 and the second focal length f2 satisfy the following two conditions: 0.5<|f1/f2|<1.5, and −35 mm<f1<−15 mm.
Claims19
A projection lens disposed in a projection device, wherein the projection lens from an image side sequentially comprises:
- a first lens group having a negative refracting power and comprising an aspherical lens surface;
- and
- a second lens group having a positive refracting power;
- wherein, the first lens group has a first focal length f1, the second lens group has a second focal length f2, and the first focal length f1 and the second focal length f2 satisfy the following two conditions:
- 0.5<|f1/f2<1.5;
- and
- −35 mm<f1<−15 mm.
A projection device, comprising:
- a projection lens from an image side sequentially comprising:
- a first lens group having a negative refracting power and comprising an aspherical lens surface;
- and
- a second lens group having a positive refracting power;
- and
- an optical element, wherein the projection lens is located between the image side and the optical element;
- wherein, the first lens group has a first focal length f1, the second lens group has a second focal length f2, and the first focal length f1 and the second focal length f2 satisfy the following two conditions:
- 0.5<|f1/f2|<1.5;
- and
- −35 mm<f1<−15 mm.
Dependencies are inferred from the claim text.