Infrared projection lens assembly and infrared projection module
OwnerChun-Sheng Lee, Chi-Chang Wang +1inventors
InventorsChun-Sheng Lee, Chi-Chang Wang, Ya-Hsin Huang
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Abstract
An infrared projection lens assembly includes, in order from the image side to the image source side: a stop, a first lens with positive refractive power, a second lens with refractive power, and a third lens with positive refractive power, wherein a radius of curvature of an image-side surface of the first lens is R1, half of a maximum view angle (field of view) of the infrared projection lens assembly is HFOV, a focal length of the infrared projection lens assembly is f, and following condition is satisfied: −18.2<R1/(sin(HFOV)*f)<−1.53, so as to provide projected light of large angle.
Claims20
An infrared projection lens assembly, comprising a stop and three lenses, in order from an image side to an image source side, comprising:
- the stop;
- a first lens with positive refractive power, comprising an image-side surface and an image source-side surface, the image-side surface of the first lens being concave near an optical axis and the image source-side surface of the first lens being convex near the optical axis, and the image-side surface and the image source-side surface of the first lens being aspheric;
- a second lens with refractive power, comprising an image-side surface and an image source-side surface, the image-side surface of the second lens being concave near the optical axis and the image source-side surface of the second lens being convex near the optical axis, and the image-side surface and the image source-side surface of the second lens being aspheric;
- and
- a third lens with positive refractive power, comprising an image-side surface and an image source-side surface, the image-side surface of the third lens being convex near the optical axis and the image source-side surface of the third lens being convex near the optical axis, and the image-side surface and the image source-side surface of the third lens being aspheric;
- wherein a radius of curvature of the image-side surface of the first lens is R1, half of a maximum view angle (field of view) of the infrared projection lens assembly is HFOV, a focal length of the infrared projection lens assembly is f, a focal length of the second lens is f2, and following conditions are satisfied:
- −18.2<R1/(sin(HFOV)*f)<−1.53 and −0.22<f/f2<0.40, wherein the ratio f/f2 must not be equal to zero.
An infrared projection module, comprising:
- a lens barrel,
- an infrared projection lens assembly disposed in the lens barrel, and a light source disposed on an image source plane of the infrared projection lens assembly,
- wherein the infrared projection lens assembly, comprising a stop and three lenses, in order from an image side to an image source side, comprising:
- the stop;
- a first lens with positive refractive power, comprising an image-side surface and an image source-side surface, the image-side surface of the first lens being concave near an optical axis and the image source-side surface of the first lens being convex near the optical axis, and the image-side surface and the image source-side surface of the first lens being aspheric;
- a second lens with refractive power, comprising an image-side surface and an image source-side surface, the image-side surface of the second lens being concave near the optical axis and the image source-side surface of the second lens being convex near the optical axis, and the image-side surface and the image source-side surface of the second lens being aspheric;
- and
- a third lens with positive refractive power, comprising an image-side surface and an image source-side surface, the image-side surface of the third lens being convex near the optical axis and the image source-side surface of the third lens being convex near the optical axis, and the image-side surface and the image source-side surface of the third lens being aspheric;
- wherein a radius of curvature of the image-side surface of the first lens is R1, half of a maximum view angle (field of view) of the infrared projection lens assembly is HFOV, a focal length of the infrared projection lens assembly is f, a focal length of the second lens is f2, and following conditions are satisfied:
- −18.2<R1/(sin(HFOV)*f)<−1.53 and −0.22<f/f2<0.40, wherein the ratio f/f2 must not be equal to zero.
Dependencies are inferred from the claim text.