Rotationally asymmetric optical system

• US 20060238879A1
• Filed: 04/25/2006
• Published: 10/26/2006
• Est. Priority Date: 04/25/2005
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Togino, Takayoshi
• Granted Patent: US 7,362,517 B2
• Time in Patent Office: Days
• US Class Current: 359/637
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 17/0804 using two curved mirrors G02B17/0864, G02B17/0896 takes precedence

Abstract

The invention relates to a rotationally asymmetric optical system for taking an image having a full 360°-direction angle of view or projecting an image onto a full 360°-direction angle of view. With the rotationally asymmetric optical system, an image in a specific direction can be more enlarged or more reduced than an image in other direction, or an image can be picked up ro projected with an angle of view in a specific direction differing from an angle of view in other direction. This rotationally asymmetric optical system comprises a full-panoramic optical system 50 which includes at least one reflecting surface 12 rotationally symmetric about a center axis, is rotationally symmetric about the center axis, and is adapted to form a full 360°-direction image on an image plane or project an image located on the image plane at a full 360°-direction angle of view, and a rotationally asymmetric optical element 60 which is located in such a way as to surround the full circumference of the entrance surface 11 of the full-panoramic optical system 50 in order of travel of light rays in the case of an image-formation optical system, and in reverse order of travel of light rays in the case of a projection optical system, and is rotationally asymmetric about the center axis.

Claims

1. A rotationally asymmetric optical system, comprising a full-panoramic optical system which includes at least one reflecting surface rotationally symmetric about a center axis, is rotationally symmetric about the center axis, and is adapted to form a full 360°

-direction image on an image plane or project an image located on the image plane onto a full 360°

-direction angle of view, and a rotationally asymmetric optical element which is located in such a way as to surround a full circumference of an entrance surface of said full-panoramic optical system in order of travel of light rays in the case of an image-formation optical system, and in reverse order of travel of light rays in the case of a projection optical system, and is rotationally asymmetric about the center axis.

2. The rotationally asymmetric optical system according to claim 1, wherein said rotationally asymmetric optical element differs in angular magnification depending on an azimuth.

3. The rotationally asymmetric optical system according to claim 1, wherein said rotationally asymmetric optical element differs in an angle of deflection along the center axis depending on an azimuth.

4. The rotationally asymmetric optical system according to claim 1, wherein, in order of travel of light rays in the case of the image-formation optical system, and in reverse order of travel of light rays in the case of the projection optical system, a light beam incident at each azimuth from the entrance surface of said full-panoramic optical system passes through said optical full-panoramic optical system to form an image at a position of the image plane off the center axis, and said rotationally asymmetric optical element differs in at least one of angular magnification in a section including the center axis and angular magnification in a section that is orthogonal to the first-mentioned section and includes a center ray of said light beam depending an azimuth.

5. The rotationally asymmetric optical system according to claim 1, wherein said rotationally asymmetric optical element comprises only a refracting surface.

6. The rotationally asymmetric optical system according to claim 1, wherein said rotationally asymmetric optical element includes a reflecting surface.

7. The rotationally asymmetric optical system according to claim 1, which satisfies the following conditions (1) and (2) with respect to Δ

Pm indicative of a powder change due to an azimuth of said rotationally asymmetric optical element in a section including the center axis and Δ

Ps indicative of a power change due to an azimuth of said rotationally asymmetric optical element in a section that is orthogonal to the section including the center axis and including a center ray;

Δ

Pm<

0.1(1/mm) 

 

(1)
Δ

Ps<

0.1(1/mm) 

 

(2)

8. The rotationally asymmetric optical system according to claim 1, wherein said rotationally asymmetric optical element is located rotatably about the center axis.

9. The rotationally asymmetric optical system according to claim 8, wherein a second rotationally asymmetric optical element is located in such a way as to surround a full circumference of said rotationally asymmetric optical element, wherein said second optical element is located rotatably about said first optical element and about an axis parallel with the center axis.

10. The rotationally asymmetric optical system according to claim 1, wherein an entrance pupil of said full-panoramic optical system lying in a section including the center axis is positioned near a transmitting surface that forms said entrance surface of said full-panoramic optical system.

11. The rotationally asymmetric optical system according to claim 1, wherein at least one reflecting surface of said full-panoramic optical system is of a rotationally symmetric shape defined by rotation about the center axis of a line segment of any arbitrary shape including an odd-number degree term.

12. The rotationally asymmetric optical system according to claim 1, wherein said full-panoramic optical system has a flare stop located near an entrance pupil in a section including the center axis, wherein said flare stop is adapted to limit an aperture only in the section including the center axis.

13. The rotationally asymmetric optical system according to claim 2, wherein said rotationally asymmetric optical element comprises only a refracting surface.

14. The rotationally asymmetric optical system according to claim 3, wherein said rotationally asymmetric optical element comprises only a refracting surface.

15. The rotationally asymmetric optical system according to claim 4, wherein said rotationally asymmetric optical element comprises only a refracting surface.

16. The rotationally asymmetric optical system according to claim 2, wherein said rotationally asymmetric optical element includes a reflecting surface.

17. The rotationally asymmetric optical system according to claim 3, wherein said rotationally asymmetric optical element includes a reflecting surface.

18. The rotationally asymmetric optical system according to claim 4, wherein said rotationally asymmetric optical element includes a reflecting surface.

19. The rotationally asymmetric optical system according to claim 2, which satisfies the following conditions (1) and (2) with respect to Δ

Pm indicative of a powder change due to an azimuth of said rotationally asymmetric optical element in a section including the center axis and Δ

Ps indicative of a power change due to an azimuth of said rotationally asymmetric optical element in a section that is orthogonal to the section including the center axis and including a center ray;

Δ

Pm<

0.1(1/mm) 

 

(1)
Δ

Ps<

0.1(1/mm) 

 

(2)

20. The rotationally asymmetric optical system according to claim 3, which satisfies the following conditions (1) and (2) with respect to Δ

Pm indicative of a powder change due to an azimuth of said rotationally asymmetric optical element in a section including the center axis and Δ

Ps indicative of a power change due to an azimuth of said rotationally asymmetric optical element in a section that is orthogonal to the section including the center axis and including a center ray;

Δ

Pm<

0.1(1/mm) 

 

(1)
Δ

Ps<

0.1(1/mm) 

 

(2)