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US 2015/0103411 A1Published application
Eyepiece optical system and electronic apparatus
AssigneeSony Corporation
InventorKenta Katagata
Life of this patent
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Abstract
An eyepiece optical system includes: a first lens having a biconvex shape in optical axis center and having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; and a fourth lens having positive refractive power. The first to fourth lenses are arranged in order from an image to be observed. The following conditional expression is satisfied, 0.47<f3/f4<3.00 (1) where f3 is a focal length of the third lens, and f4 is a focal length of the fourth lens.
Claims8
An eyepiece optical system comprising:
- a first lens having a biconvex shape in optical axis center and having positive refractive power;
- a second lens having negative refractive power;
- a third lens having positive refractive power;
- and
- a fourth lens having positive refractive power, the first to fourth lenses being arranged in order from an image to be observed, wherein
- the following conditional expression is satisfied,
- 0.47<f3/f4<3.00 (1)
- where f3 is a focal length of the third lens, and
- f4 is a focal length of the fourth lens.
6 more elements
An electronic apparatus comprising:
- an image display device;
- and
- an eyepiece optical system configured to allow observation, in an enlarged manner, of an image displayed on the image display device,
- the eyepiece optical system including
- a first lens having a biconvex shape in optical axis center and having positive refractive power,
- a second lens having negative refractive power,
- a third lens having positive refractive power, and
- a fourth lens having positive refractive power, the first to fourth lenses being arranged in order from an image to be observed, wherein
- the following conditional expression is satisfied,
- 0.47<f3/f4<3.00 (1)
- where f3 is a focal length of the third lens, and
- f4 is a focal length of the fourth lens.
9 more elements
Dependencies are inferred from the claim text.