Lens testing apparatus and a lens adjusting apparatus

• US 5,999,251 A
• Filed: 02/27/1998
• Issued: 12/07/1999
• Est. Priority Date: 12/16/1997
• Status: Expired due to Term

• Current Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Original Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Inventors: Arimoto, Tetsuya, Teramoto, Tougo
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US09/031,607
• Time in Patent Office: 648 Days
• Field of Search: 356/124, 356/125, 356/126, 356/127, 356/400, 356/399, 356/153, 359/504, 359/506, 359/811-830, 250/201.1, 250/206.2
• US Class Current: 356/127
• CPC Class Codes: G01M 11/0221 by determining the optical axis or position of lenses

Abstract

A lens testing apparatus detects and evaluates inclination of the image plane as caused by decentering of an optical system. The apparatus has an image provider, a plurality of focusing position detectors, and a calculator. The image provider provides an image to a lens system to be tested for decentering. The detectors detect a focusing position on which light rays exiting from the lens system focus. The calculator calculates inclination of the image plane based on the focusing position detected by the detectors.

Claims

1. A lens testing apparatus comprising:

a plurality of focusing position detectors for detecting a focusing position on which light rays exiting from a lens system to be tested focus; and

a calculator for calculating inclination of an image plane caused by relative decentering of lens components in said lens system based on the focusing position detected by said plurality of focusing position detectors.

2. A lens testing apparatus as claimed in claim 1, wherein said plurality of focusing position detectors are arranged along a circumference of a circle symmetrically with respect to the optical axis of said lens system to be tested.

3. A lens testing apparatus as claimed in claim 1, wherein two focusing position detectors are arranged along said circumference symmetrically with respect to said optical axis.

4. A lens testing apparatus as claimed in claim 1, wherein said focusing position detectors each have a detecting optical system that matches said lens system to be tested with a pupil.

5. A lens testing apparatus as claimed in claim 4, wherein said focusing position detectors use a phase-difference detection method.

6. A lens testing apparatus as claimed in claim 4, wherein said detecting optical system is used to re-image an image.

7. A lens testing apparatus as claimed in claim 6, wherein said focusing position detectors use a phase-difference detection method.

8. A lens adjusting apparatus for adjusting a lens system by centering it with respect to an optical axis of an imaging optical system that includes at least said lens system, comprising:

a holder for holding said lens system to be centered in such a way as to be adjustable at least in a direction perpendicular to the optical axis of said imaging optical system;

a plurality of focusing position detectors for detecting a focusing position on which light rays exiting from said imaging optical system focus;

a calculator for calculating inclination of an image plane caused by relative decentering of said imaging optical system based on the focusing position detected by said plurality of focusing position detectors; and

a controller for specifying a movement direction in which said lens system to be centered should be moved from its current position to reach a position at which optimal optical performance is obtained based on the inclination of said image plane calculated by said calculator.

9. A lens adjusting apparatus as claimed in claim 8, wherein said plurality of focusing position detectors are arranged along a circumference of a circle symmetrically with respect to the optical axis of said imaging optical system.

10. A lens adjusting apparatus as claimed in claim 9, wherein two focusing position detectors are arranged along said circumference symmetrically with respect to said optical axis.

11. A lens adjusting apparatus as claimed in claim 8, wherein, after the movement direction is specified by said controller, movement amount is calculated.

12. A lens adjusting apparatus as claimed in claim 8, wherein said focusing position detectors each have a detecting optical system that matches said imaging optical system with a pupil.

13. A lens adjusting apparatus as claimed in claim 12, wherein said detecting optical system is used to re-image an image.

14. A lens adjusting apparatus as claimed in claim 13, wherein said focusing position detectors use a phase-difference detection method.

15. A lens testing apparatus comprising:

an image provider for providing an image to a lens system to be tested for decentering;

a plurality of focusing position detectors for detecting a focusing position on which light rays exiting from said lens system to be tested focus; and

a calculator for calculating inclination of an image plane caused by relative decentering of lens components of said lens system based on the focusing position detected by said plurality of focusing position detectors.

16. A lens testing apparatus as claimed in claim 15, wherein said plurality of focusing position detectors are arranged along a circumference of a circle symmetrically with respect to the optical axis of said lens system to be tested.

17. A lens testing apparatus as claimed in claim 15, wherein two focusing position detectors are arranged along said circumference symmetrically with respect to said optical axis.

18. A lens testing apparatus as claimed in claim 15, wherein said focusing position detectors each have a detecting optical system that matches said lens system to be tested with a pupil.

19. A lens testing apparatus as claimed in claim 18, wherein said focusing position detectors use a phase-difference detection method.

20. A lens testing apparatus as claimed in claim 18, wherein said detecting optical system is used to re-image an image.

21. A lens testing apparatus as claimed in claim 20, wherein said focusing position detectors use a phase-difference detection method.

22. A lens adjusting apparatus for adjusting a lens system by centering it with respect to an optical axis of an imaging optical system that includes at least said lens system, comprising:

an image provider for providing an image to said lens system to be centered;

a holder for holding said lens system to be centered in such a way as to be adjustable at least in a direction perpendicular to the optical axis of said imaging optical system;

a plurality of focusing position detectors for detecting a focusing position on which light rays exiting from said imaging optical system focus;

a calculator for calculating inclination of an image plane caused by relative decentering of said imaging optical system based on the focusing position detected by said plurality of focusing position detectors; and

a controller for specifying a movement direction in which said lens system to be centered should be moved from its current position to reach a position at which optimal optical performance is obtained based on the inclination of said image plane calculated by said calculator.

23. A lens adjusting apparatus as claimed in claim 22, wherein said plurality of focusing position detectors are arranged along a circumference of a circle symmetrically with respect to the optical axis of said imaging optical system.

24. A lens adjusting apparatus as claimed in claim 23, wherein two focusing position detectors are arranged along said circumference symmetrically with respect to said optical axis.

25. A lens adjusting apparatus as claimed in claim 22, wherein, after the movement direction is specified by said controller, movement amount is calculated.

26. A lens adjusting apparatus as claimed in claim 22, wherein said focusing position detectors each have a detecting optical system that matches said imaging optical system with a pupil.

27. A lens adjusting apparatus as claimed in claim 26, wherein said focusing position detectors use a phase-difference detection method.

28. A lens adjusting apparatus as claimed in claim 26, wherein said detecting optical system is used to re-image an image.

29. A lens adjusting apparatus as claimed in claim 28, wherein said focusing position detectors use a phase-difference detection method.