Optical system, display apparatus, and image pickup apparatus
AssigneeCanon Kabushiki Kaisha
InventorsTomohiro INO, Takaho MATSUDA
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Abstract
Optical systems, display apparatuses, and image pickup apparatuses are provided herein. One or more optical systems configured to guide light from a display element to an observation side, may include a plurality of lenses that consist of, in order from a display element side to the observation side, a first lens with positive refractive power, a second lens with negative refractive power, a third lens with refractive power, and a fourth lens with refractive power. A predetermined inequality is satisfied.
Claims13
An optical system configured to guide light from a display element to an observation side, the optical system comprising a plurality of lenses, the plurality of lenses consisting of, in order from a display element side to the observation side:
- a first lens with positive refractive power;
- a second lens with negative refractive power;
- a third lens with refractive power;
- and
- a fourth lens with refractive power,
- wherein the following inequalities are satisfied:
- -
- 1
-
- 0
- .
- 0
-
- 0
- <
- f
-
- 4
- /
- f
-
- 3
- <
- 0
- .15
- -
- 5.
- <
- (
- R
-
- 4
-
- 1
- +
- R
-
- 4
-
- 2
- )
- /
- (
- R
-
- 41
- -
- R
-
- 42
- )
- <
- -
- 0.19
- 0.5
- <
- LD
- /
- L
-
- 1
- <
- 4
-
- 0
- .
- 0
- where f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, R41 is a radius of curvature of a display-element-side surface of the fourth lens, R42 is a radius of curvature of an observation-side surface of the fourth lens, L1 is an air-equivalent distance from a display surface of the display element to a display-element-side surface of the first lens in a case where diopter is −1 diopter, and LD is a distance on an optical axis from the display-element-side surface of the first lens to the observation-side surface of the fourth lens.
A display apparatus comprising:
- an optical system configured to guide light from a display element to an observation side;
- and
- the display element;
- wherein the optical system that includes a plurality of lenses, the plurality of lenses consisting of, in order from the display element side to the observation side:
- a first lens with positive refractive power;
- a second lens with negative refractive power;
- a third lens with refractive power;
- and
- a fourth lens with refractive power,
- wherein the following inequalities are satisfied:
- -
- 10.
-
- 0
-
- 0
- <
- f
-
- 4
- /
- f
-
- 3
- <
- 0
- .15
- -
- 5.
- <
- (
- R
-
- 4
-
- 1
- +
- R
-
- 4
-
- 2
- )
- /
- (
- R
-
- 41
- -
- R
-
- 42
- )
- <
- -
- 0.19
- 0.5
- <
- LD
- /
- L
-
- 1
- <
- 4
-
- 0
- .
- 0
- where f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, R41 is a radius of curvature of a display-element-side surface of the fourth lens, R42 is a radius of curvature of an observation-side surface of the fourth lens, L1 is an air-equivalent distance from a display surface of the display element to a display-element-side surface of the first lens in a case where diopter is −1 diopter, and LD is a distance on an optical axis from the display-element-side surface of the first lens to the observation-side surface of the fourth lens.
An image pickup apparatus comprising:
- an image sensor;
- and
- an electronic viewfinder that includes an optical system configured to guide light from a display element to an observation side;
- and
- the display element;
- wherein the optical system that includes a plurality of lenses, the plurality of lenses consisting of, in order from the display element side to the observation side:
- a first lens with positive refractive power;
- a second lens with negative refractive power;
- a third lens with refractive power;
- and
- a fourth lens with refractive power,
- wherein the following inequalities are satisfied:
- -
- 10.
-
- 0
-
- 0
- <
- f
-
- 4
- /
- f
-
- 3
- <
- 0
- .15
- -
- 5.
- <
- (
- R
-
- 4
-
- 1
- +
- R
-
- 4
-
- 2
- )
- /
- (
- R
-
- 41
- -
- R
-
- 42
- )
- <
- -
- 0.19
- 0.5
- <
- LD
- /
- L
-
- 1
- <
- 4
-
- 0
- .
- 0
- where f3 is a focal length of the third lens, f4 is a focal length of the fourth lens, R41 is a radius of curvature of a display-element-side surface of the fourth lens, R42 is a radius of curvature of an observation-side surface of the fourth lens, L1 is an air-equivalent distance from a display surface of the display element to a display-element-side surface of the first lens in a case where diopter is −1 diopter, and LD is a distance on an optical axis from the display-element-side surface of the first lens to the observation-side surface of the fourth lens.
Dependencies are inferred from the claim text.