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High resolution non-contact interior profilometer

Imported: 23 Feb '17 | Published: 22 Oct '02

Martin S. Piltch, R. Alan Patterson, Gerald W. Leeches, John Van Nierop, John J. Teti, Jr.

USPTO - Utility Patents

Abstract

Apparatus and method for inspecting the interior surfaces of devices such as vessels having a single entry port. Laser energy is introduced into a device under test and to a time delay. Light reflected from the interior surfaces of the device under test is introduced into one end of a dye-cell and the time-delayed light is introduced into the other end. The amount of time delay is adjusted to produce two-photon fluorescence in the dye-cell so that the amount of time delay is representative of the interior surfaces of the device under test.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the components of the present invention.

FIG. 2 is a schematical illustration of one of the dye cell units for output from the present invention.

FIG. 3 is a side view detail of the end of three optical fibers inserted into a device under test to be inspected so that upon rotation and translation of the device under test virtually all of the interior surface can be inspected.

FIGS. 4A and 4B are schematical drawings of a micro-positioned mirror used to inspect the interior surface of a device under test instead of the ends of optical fibers.

FIG. 5 is a block diagram of the control portion of the present invention and its interconnection to other control devices.

Claims

1. Apparatus for inspecting the interior of a device under test through a single port in the device under test comprising:

2. The apparatus as described in claim 1, further comprising fixture means for holding said device under test and for controllably positioning said device under test relative to said first at least one optical fibers.

3. The apparatus as described in claim 1, wherein said first and second at least one optical fibers each comprises three optical fibers.

4. The apparatus as described in claim 3, wherein said first at least one optical fibers comprise three optical fibers wherein two of said three optical fibers have ends that are cut at 45° angle surfaces and direct light at a right angle with respect to said light traversing said two of said three optical fibers.

5. The apparatus as described in claim 4, wherein said two optical fibers have reflective coating applied to said 45° angle surfaces.

6. The apparatus as described in claim 3, wherein said first at least one optical fibers comprise three optical fiber wherein two of said three optical fibers have ends that are cut at an angle of less than 45°.

7. The apparatus as described in claim 1, further comprising camera means in optical contact with said two-photon fluorescence for imaging said two-photon fluorescence and outputting said image.

8. The apparatus as described in claim 2, further comprising computer means receiving said image for displaying and analyzing said image, and for controlling said fixture means.

9. The apparatus as described in claim 1 wherein said laser energy is modulated using short pulse modulation.

10. The apparatus as described in claim 1 wherein said laser energy is modulated using frequency modulated continuous wave modulation.

11. The apparatus as described in claim 1 wherein said laser energy is modulated using stepped frequency phase measurement modulation.

12. The apparatus as described in claim 1 wherein said elongate dye-cell means is filled with a dilute alcohol solution of an organic dye that fluoresces at a wavelength of one-half that of said laser energy.

13. The apparatus as described in claim 1 wherein said laser means comprise a titanium-doped sapphire crystal excited by a frequency doubled, Nd doped, lithium vanadate laser.

14. The apparatus as described in claim 1 wherein said first at least one optical fiber connect to a scanning at least one micro-positioned mirror for reflecting laser energy to interior surfaces of said device under test and reflecting laser energy reflected from said interior surfaces into said first at least one optical fiber.

15. The apparatus as described in claim 14, wherein said at least one micro-positioned mirror is rotatable about its axis.

16. A method of inspecting the interior surfaces of a device under test having a single entry port comprising the steps of:

17. The method as described in claim 16, further comprising the step of rotating and translating said device under test.

18. The method as described in claim 17, further comprising the step of directing said light toward virtually all of said interior surfaces.

19. The method as described in claim 16 wherein said laser energy is modulated using short pulse modulation.

20. The method as described in claim 16 wherein said laser energy is modulated using frequency modulated continuous wave modulation.

21. The method as described in claim 16 wherein said laser energy is modulated using stepped frequency phase measurement modulation.