Concentric optical system

• US 5,644,436 A
• Filed: 03/17/1995
• Issued: 07/01/1997
• Est. Priority Date: 03/18/1994
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Togino, Takayoshi, Nakagiri, Kunie
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): BEY, DAWN MARIE
• Application Number:
  US08/405,711
• Time in Patent Office: 837 Days
• Field of Search: 359/643, 359/644, 359/645, 359/646, 359/647, 359/726, 359/727, 359/728, 359/729, 359/730, 359/731, 359/732, 359/839, 359/853, 359/858, 359/859
• US Class Current: 359/731
• CPC Class Codes: G02B 13/18 with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration G02B13/002 takes precedence
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features

Abstract

A concentric optical system usable as either an imaging optical system or an ocular optical system, which enables a clear image to be obtained at a field angle of up to about 90° and with a pupil diameter of up to about 10 millimeters with substantially no chromatic aberration. The concentric optical system includes a first optical component having a first semitransparent reflecting surface (2), and a second optical component having a second semitransparent reflecting surface (3). The first and second semitransparent reflecting surfaces (2 and 3) have respective centers of curvature disposed at approximately the same position (1). The first and second optical components are different in dispersion from each other. The first and second semitransparent reflecting surfaces (2 and 3) are arranged so that a bundle of light rays passing through the first semitransparent reflecting surface (2) is reflected by the second semitransparent reflecting surface (3), and the bundle of light rays reflected by the second semitransparent reflecting surface (3) is reflected by the first semitransparent reflecting surface (2) and then passes through the second semitransparent reflecting surface (3). The optical system satisfies the condition of 0.2<ν₁ /ν₂ <1.00, where ν₁ is the Abbe'"'"'s number of the first optical component, and ν₂ is the Abbe'"'"'s number of the second optical component.

Claims

1. A concentric optical system comprising:

at least two semitransparent reflecting surfaces each being convex toward an image side of said concentric optical system; and

a turn-back optical path defined such that light passing through one of said at least two semitransparent reflecting surfaces is reflected at the other of said at least two semitransparent reflecting surfaces, then is reflected at said one of said at least two semitransparent reflecting surfaces, and finally is transmitted by said other of said at least two semitransparent reflecting surfaces;

said turn-back optical path including;

a first medium having a first dispersion, and

a second medium having a second dispersion different from said first dispersion; and

each of said at least two semitransparent reflecting surfaces having a transmittance in a range of from 20% to 80%.

2. A concentric optical system according to claim 1, further comprising:

two optical components, said at least two semitransparent optical components being on said two optical components;

said at least two semitransparent optical components lying adjacent to each other.

3. A concentric optical system according to claim 2, wherein:

said at least two semitransparent reflecting surfaces and said turn-back optical path form an ocular optical system.

4. A concentric optical system according to claim 2, wherein:

said at least two semitransparent reflecting surfaces and said turn-back optical path form an imaging optical system.

5. A concentric optical system according to claim 2, 4, or 1, further comprising:

a first optical component and a second optical component, said at least two semitransparent optical components being on said first optical component and said second optical component;

said concentric optical system satisfying the following condition;

space="preserve" listing-type="equation">0.2<

ν

.sub.1 /ν

.sub.2 <

1.00 (1)

where ν

₁ is a first Abbe'"'"'s number of said first optical component, and ν

₂ is a second Abbe'"'"'s number of said second optical component.

6. A concentric optical system according to claim 2, further comprising:

a first optical component and a second optical component, said at least two semitransparent optical components being on said first optical component and said second optical component;

said concentric optical system satisfying the following condition when a field angle in each of vertical and horizontal directions is 40°

or more;

space="preserve" listing-type="equation">0.5<

ν

.sub.1 /ν

.sub.2 <

0.98 (2)

where ν

₁ is a first Abbe'"'"'s number of said first optical component, and ν

₂ is a second Abbe'"'"'s number of said second optical component.

7. A concentric optical system according to claim 2, further comprising:

a first optical component and a second optical component, said at least two semitransparent optical components being on said first optical component and said second optical component;

said concentric optical system satisfying the following condition when a field angle in each of vertical and horizontal directions is 40°

or more, and a pupil diameter is 10 millimeters or more;

space="preserve" listing-type="equation">0.5<

ν

.sub.1 /ν

.sub.2 <

0.95 (3)

where ν

₁ is a first Abbe'"'"'s number of said first optical component, and ν

₂ is a second Abbe'"'"'s number of said second optical component.

8. A concentric optical system comprising:

a first optical component including a first semitransparent reflecting surface on a pupil side of said concentric optical system, said first optical component containing a first medium having a first dispersion;

a second optical component including a second semitransparent reflecting surface on a side of said concentric optical system opposite to said pupil side of said concentric optical system, said second optical component containing a second medium having a second dispersion different from said first dispersion; and

means for cutting off light rays passing through said first transparent reflecting surface and said second transparent reflecting surface without being reflected by either of said first transparent reflecting surface and said second transparent reflecting surface, said cut-off means including;

a polarizing optical element;

both said first semitransparent reflecting surface and said second semitransparent reflecting surface being shaped such that a respective concave surface thereof is directed toward said pupil side of said concentric optical system; and

said first optical component being located toward said pupil side of said concentric optical system with respect to said second optical component.

10. A concentric optical system according to claim 8 or 9, wherein:

said first semitransparent reflecting surface and said second semitransparent reflecting surface lie adjacent to each other.

11. A concentric optical system according to claim 8 or 9, wherein:

said first optical component, said second optical component, said first transparent reflecting surface, and said second transparent reflecting surface form an ocular optical system.

12. A concentric optical system according to claim 8 or 9, wherein:

said first optical component, said second optical component, said first transparent reflecting surface, and said second transparent reflecting surface form an imaging optical system.

13. A concentric optical system according to claim 8 or 9, wherein said concentric optical system satisfies the following condition:

space="preserve" listing-type="equation">0.2<

ν

.sub.1 /ν

.sub.2 <

1.00 (1)

where ν

₁ is a first Abbe'"'"'s number of said first optical component, and ν

₂ is a second Abbe'"'"'s number of said second optical component.

14. A concentric optical system according to claim 8 or 9, wherein said concentric optical system satisfies the following condition when a field angle in each of vertical and horizontal directions is 40°

or more;

space="preserve" listing-type="equation">0.5<

ν

.sub.1 /ν

.sub.2 <

0.98 (2)

where ν

₁ is a first Abbe'"'"'s number of said first optical component, and ν

₂ is a second Abbe'"'"'s number of said second optical component.

15. A concentric optical system according to claim 8 or 9, wherein said concentric optical system satisfies the following condition when a field angle in each of vertical and horizontal directions is 40°

or more, and a pupil diameter is 10 millimeters or more;

space="preserve" listing-type="equation">0.5<

ν

.sub.1 /.sub.2 <

0.95 (3)

where ν

₁ is a first Abbe'"'"'s number of said first optical component, and ν

₂ is a second Abbe'"'"'s number of said second optical component.

9. A concentric optical system comprising:

a first optical component including a first semitransparent reflecting surface on a pupil side of said concentric optical system, said first optical component containing a first medium having a first dispersion; and

a second optical component including a second semitransparent reflecting surface on a side of said concentric optical system opposite to said pupil side of said concentric optical system, said second optical component containing a second medium having a second dispersion different from said first dispersion;

both said first semitransparent reflecting surface and said second semitransparent reflecting surface being shaped such that a respective concave surface thereof is directed toward said pupil side of said concentric optical system;

said first optical component being located toward said pupil side of said concentric optical system with respect to said second optical component; and

each of said first transparent reflecting surface and said second transparent reflecting surface has a transmittance in a range of from 20% to 80%.

16. A concentric optical system comprising:

two optical components;

two semitransparent reflecting surfaces on said two optical components;

each of said two semitransparent reflecting surfaces having a concave surface directed toward a pupil plane of said concentric optical system;

said two semitransparent reflecting surfaces being disposed such that each of said two semitransparent reflecting surfaces transmits light rays at least once and reflects light rays at least once;

said two optical components each having a dispersion different from one another; and

said two optical components being arranged such that a pupil that is formed by said two optical components lies outside a range of from a foremost surface to a rearmost surface of said concentric optical system; and

means for cutting off light rays passing through said two semitransparent reflecting surfaces without being reflected by either of said two semitransparent reflecting surfaces, said cut-off means including;

a polarizing optical element.

17. A concentric optical system comprising:

a first optical component having a first semitransparent reflecting surface which has a center of curvature disposed substantially on an optical axis, and which has a concave surface directed toward said center of curvature, said first optical component being formed from a medium having a refractive index (n) larger than 1 (n>

1);

a second optical component having a second semitransparent reflecting surface which has a center of curvature disposed at approximately the same position as the center of curvature of said first semitransparent reflecting surface, said second optical component being formed from a medium having a refractive index (n) larger than 1 (n>

1); and

means for cutting off light rays passing through said at least two semitransparent reflecting surfaces without being reflected by either of them, said cut-off means including a polarizing optical element;

said medium of said first optical component and said medium of said second optical component being different in dispersion from each other; and

said first and second optical components being arranged so that a pupil that is formed by said first and second optical components lies outside a range of from a foremost surface to a rearmost surface of the optical system.

18. A concentric optical system comprising:

a first optical component having a first semitransparent reflecting surface;

a second optical component having a second semitransparent reflecting surface; and

means for cutting off light rays passing through said at least two semitransparent reflecting surfaces without being reflected by either of them, said cut-off means including a polarizing optical element;

said first and second semitransparent reflecting surfaces having respective centers of curvature disposed at approximately the same position;

said first and second optical components being different in dispersion from each other;

said first and second semitransparent reflecting surfaces being arranged so that a bundle of light rays passing through said first semitransparent reflecting surface is reflected by said second semitransparent reflecting surface, and the bundle of light rays reflected by said second semitransparent reflecting surface is reflected by said first semitransparent reflecting surface and then passes through said second semitransparent reflecting surface; and

said first and second optical components being arranged so that a pupil that is formed by said first and second optical components lies outside a range of from a foremost surface to a rearmost surface of the optical system.