Lens measuring method and device for determining decenter and tilt of the lens

• US 20070201037A1
• Filed: 08/31/2006
• Published: 08/30/2007
• Est. Priority Date: 09/06/2005
• Status: Active Grant

• Current Assignee: National Applied Research Laboratories (Government of The Republic of China)
• Original Assignee: Instrument Technology Research Center
• Inventors: Huang, Kuo-Cheng, Wu, Wen, Lee, Chien-Shing, Yu, Jung-Ru
• Granted Patent: US 7,535,557 B2
• Time in Patent Office: Days
• US Class Current: 356/515
• CPC Class Codes: G01B 11/272 using photoelectric detection means

Abstract

A device for measuring a lens, comprising a first interferometer having a first optical axis and carried on a first adjustment base, a lens holder for holding the lens having a first surface having a first lens optical axis and a second surface having a second lens optical axis, and a platen having a sliding rail and carrying the first adjustment base and the lens holder thereon, wherein the lens holder is movable on the sliding rail, wherein each of the first adjustment base and the lens holder has a tetra-axis adjustment mechanism through which a relative positional relationship of the first optical axis of the first interferometer and the first lens optical axis of the first surface of the lens is adjustable.

Claims

1. A device for measuring a lens, comprising:

a first interferometer having a first optical axis and carried on a first adjustment base;

a lens holder for holding the lens having a first surface having a first lens optical axis and a second surface having a second lens optical axis; and

a platen having a sliding rail and carrying the first adjustment base and the lens holder thereon, wherein the lens holder is movable on the sliding rail,

wherein each of the first adjustment base and the lens holder has a tetra-axis adjustment mechanism through which a relative positional relationship of the first optical axis of the first interferometer and the first lens optical axis of the first surface of the lens is adjustable.

2. The device as claimed in claim 1, wherein the tetra-axis adjustment mechanism comprises two translation axes and two rotation axes.

3. The device as claimed in claim 1, wherein the lens holder has a 180 degrees overturn mechanism through which the first and second lens optical axes of the first and second surfaces are calibrated in turn with respect to the first optical axis of the first interferometer.

4. The device as claimed in claim 1, further comprising a second interferometer having a second lens optical axis and disposed on a second adjustment base on the platen to measure a relative positional relationship of the second lens optical axis of the second surface and the second optical axis of the second interferometer.

5. The device as claimed in claim 1, wherein the device is used to measure a decenter and a tilt of the lens.

6. A method for measuring a decenter amount and a tilt amount of a lens, comprising the steps of:

providing an interferometer having an optical axis and the lens, wherein the lens has a first lens optical axis and a second lens optical axis;

arranging the optical axis of the interferometer and the first lens optical axis of the first surface into having a first specific relative positional relationship therebetween;

rotating the lens by 180 degrees;

adjusting the second optical axis of the lens and the optical axis of the interferometer into having a second specific relationship therebetween and recording a first adjusted translation amount Δ

y, a second adjusted translation amount Δ

z, a first adjusted angular amount Δ

θ

_y and a second adjusted angular amount Δ

θ

_z required to be adjusted; and

calculating the respective one of the decenter amount δ and

the tilt amount Δ

θ

existing between the first and second lens optical axes according to the first and second adjusted translation amounts Δ

y and Δ

z and the first and second adjusted angular amounts Δ

θ

_y and Δ

θ

_z.

7. The method as claimed in claim 6, wherein each of the first and second specific relationships is a relationship where the optical axis of the interferometer and the first and second lens optical axes of the first and second surfaces totally coincide with each other.

8. The method as claimed in claim 7, wherein the optical axis of the interferometer and the first and second lens optical axes of the first and second surfaces are adjusted to totally coincide with one another by observing interfering fringes formed as an interferogram.

9. The method as claimed in claim 8, wherein a distance between the lens and the interferometer is adjusted to present the interfering fringes.

10. The method as claimed in claim 8, wherein the optical axis of the interferometer and the first and second lens optical axes of the lens are adjusted to totally coincide with one another by observing whether the interfering fringes are formed as concentric rings and whether the concentric rings are positioned at a center of the interferogram.

11. The method as claimed in claim 6, wherein the first and second specific relationships are identical to each other.

12. A method for measuring a decenter amount and a tilt amount of a lens, comprising the steps of:

providing a first interferometer having a first optical axis, a second interferometer having a second optical axis and the lens, wherein the lens has a first surface having a first lens optical axis and a second surface having a second lens optical axis, and the first and second interferometers face the first and second surfaces of the lens respectively;

adjusting the first interferometer and the lens so that the first lens optical axis of the first surface and the first optical axis of the first interferometer have a first specific relative positional relationship therebetween;

adjusting the second lens optical axis of the second surface of the lens and the second optical axis of the second interferometer into having a second specific relative positional relationship therebetween and recording a first adjusted translation amount Δ

y, a second adjusted translation amount Δ

z, a first adjusted angular amount Δ

θ

_y and a second adjusted angular amount Δ

θ

_z; and

calculating the decenter amount δ and

the tilt amount Δ

θ

existing between the first and second lens optical axes of the first and second surfaces according to the first and second specific relative positional relationships and the first and second adjusted translation amounts Δ

y and Δ

z and the first and second adjusted angular amounts Δ

θ

_y and Δ

θ

_z.

13. The method as claimed in claim 12, wherein each of the first and second specific relationships is a relationship where the first and second optical axes of the first and second interferometers and the first and second lens optical axes of the first and second surfaces totally coincide with one another.

14. The method as claimed in claim 13, wherein the optical axes of the first and second interferometers and the first and second lens optical axes of the first and second surfaces are adjusted to totally coincide with one another by observing interfering fringes formed as an interferogram.

15. The method as claimed in claim 14, wherein a first distance between the first surface of the lens and the first interferometer and a second distance between the second surface of the lens and the second interferometer are adjusted respectively to present the interfering fringes.

16. The method as claimed in claim 14, wherein the optical axes of the first and second interferometers and the first and second lens optical axes of the first and second surfaces are adjusted to totally coincide with one another by observing whether the interfering fringes are formed as concentric rings and whether the concentric rings are positioned at a center of the interferogram.

17. The method as claimed in claim 12, wherein the first and second specific relationships are identical to each other.