Optical systems
AssigneeZhejiang Sunny Optics Co., Ltd.
InventorsBiran Chen, Xiaobin Zhang, Lin Huang
Life of this patent
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Abstract
The present disclosure discloses an optical system, including: a first lens having a positive refractive power, a reflective polarizing element, a first quarter wave plate, a second lens having a positive refractive power, a third lens having a negative refractive power, a partially reflective element, a fourth lens having a refractive power, a second quarter wave plate and a polarizer. An effective focal length f1 of the first lens and an effective focal length f2 of the second lens satisfy: 0.15<f2/f1<1.6; and center thicknesses CT1, CTR, CTQ1 and CT2 of the first lens, the reflective polarizing element, the first quarter wave plate and the second lens respectively on the optical axis satisfy: 0.35<(CT1+CTR)/(CTQ1+CT2)<1.05.
Claims16
An optical system, comprising sequentially along an optical axis from a first side to a second side:
- a first lens having a positive refractive power;
- a reflective polarizing element;
- a first quarter wave plate;
- a second lens having a positive refractive power;
- a third lens having a negative refractive power;
- a partially reflective element;
- a fourth lens having a positive refractive power or a negative refractive power;
- a second quarter wave plate;
- and
- a polarizer;
- wherein, the reflective polarizing element is disposed on a second side surface of the first lens, a first side surface of the reflective polarizing element is at least partially adhered to the second side surface of the first lens;
- the first quarter wave plate is disposed on a second side surface of the reflective polarizing element, a first side surface of the first quarter wave plate is at least partially adhered to the second side surface of the reflective polarizing element, and a second side surface of the first quarter wave plate is at least partially adhered to a first side surface of the second lens;
- the second lens is cemented to the third lens;
- and the third lens is cemented to the fourth lens;
- the optical system satisfies:
- 0.15
- <
- f
-
- 2
- /
- f
-
- 1
- <
- 1.6
- ,
- and
- 0.35
- <
- (
- CT
-
- 1
- +
- CTR
- )
- /
- (
- CTQ
-
- 1
- +
- CT
-
- 2
- )
- <
- 1.05
- ,
- wherein, f2 is an effective focal length of the second lens, f1 is an effective focal length of the first lens, CT1 is a center thickness of the first lens on the optical axis, CTR is a center thickness of the reflective polarizing element on the optical axis, CTQ1 is a center thickness of the first quarter wave plate on the optical axis, and CT2 is a center thickness of the second lens on the optical axis.
Dependencies are inferred from the claim text.