Granted Patent B2

US 7,302,148 · App. 11/112,172 · Granted Nov 27, 2007

Abstract

Claims (75)

1. Apparatus comprising:

a block of material having a plurality of optical paths extending therethrough;

at least one of said optical paths comprising an input optical path for communicating laser light from a laser light source to a workpiece being inspected;

at least one of said optical paths comprising an output optical path for communicating light reflected from said workpiece to a detector; and

a motor for causing relative motion between said block of material and said workpiece during use,

wherein said material is not present in said optical paths.

2. Apparatus of claim 1

wherein said block is a monolithic block of material.

3. Apparatus of claim 1 further comprising:

one or more lenses within said input optical path for concentrating said light onto said workpiece;

one or more lenses within said output optical path for collecting light reflected by said workpiece; and

one or more lenses for concentrating light form said output path onto said detector,

at least one of said lenses being within said block of material.

4. Apparatus of claim 1 wherein said block comprises a plurality of output paths for communicating reflected light to associated detectors.

5. Apparatus of claim 1 wherein said block of material is opaque.

6. Apparatus of claim 1 wherein said light exits said block of material prior to striking said workpiece and reflects back into said block of material after striking said workpiece.

7. Apparatus of claim 1 wherein said apparatus comprises one or more lenses within at least one of said optical paths for concentrating and/or collecting light, said one or more lenses being coated with an antireflective layer.

8. Apparatus of claim 1 wherein a mask is provided in at least one of said optical paths within said block of material for blocking at least a portion of the light passing therethrough.

9. Apparatus of claim 1 further comprising an iris at one end of the output optical path for controlling the amount of light striking the detector.

10. Apparatus of claim 1 wherein said block is adjustable with three degrees of freedom relative to said workpiece.

11. Apparatus of claim 1 further comprising at least one lens that both collects diverging light reflected from said workpiece and concentrates said light onto the detector.

12. Apparatus of claim 1 further comprising a lens concentrating light directly onto said workpiece.

13. Apparatus of claim 1 further comprising said workpiece, said workpiece being a platter.

14. A method for making an optical test head comprising:

providing one or more input optical paths within a block of material for permitting light to travel from a laser source to a workpiece located outside of said block of material;

providing one or more output optical paths within said block of material for permitting light to travel from said workpiece to a detector, wherein said providing of one or more input optical paths and said providing of one or more output optical paths comprise removing material from said block of material, said optical paths being where said material has been removed;

removing a portion of said block of material to expose first and second parts of one or more of said optical paths;

and affixing a mirror against said block to reflect light from said first part to said second part of said one or more optical paths.

15. Method of claim 14 wherein said providing of one or more input optical paths and said one or more output optical paths comprises milling or EDM.

16. Method of claim 14 further comprising:

providing light absorptive material in at least one of said optical paths to absorb stray light; and

providing at least one lens in one of said optical paths, said method further comprising providing an antireflective coating on said at least one lens, said at least one lens being within said block of material.

17. Method of claim 14 further comprising providing at least one mask in at least one of said optical paths within said block of material for minimizing the amount of stray light passing therethrough.

18. Method of claim 14 further comprising providing an iris at one end of at least one of said one or more output optical paths.

19. Method of claim 14 further comprising providing one or more lenses within said input optical path within said block of material and one or more lenses within said output optical path within said block of material.

20. Method of claim 14 wherein said block of material is opaque.

21. Method of claim 14 further comprising providing a lens for concentrating light directly onto said workpiece.

22. Apparatus comprising:

a block of material having a plurality of optical paths extending therethrough;

at least one of said optical paths comprising an input optical path for communicating laser light from a laser light source to a workpiece being inspected;

at least one of said optical paths comprising an output optical path for communicating light reflected from said workpiece to a detector;

said block of material moving relatives to said workpiece during use, wherein said material is not present in said optical paths; and

a sensor for receiving light from said output optical path and generating therefrom a signal indicative of the angle at which light specularly reflects off said workpiece.

23. Apparatus of claim 22 further comprising a sensor for receiving light from another output optical path and generating therefrom a signal indicative of the amount of light that scatters off the workpiece surface at a predetermined range of angles.

24. A method for making an optical test head comprising:

providing one or more input optical paths within a block of material for permitting light to travel from a laser source to a workpiece located outside of said block of material;

providing one or more output optical paths within said block of material for permitting light to travel from said workpiece to a detector, wherein said providing of one or more input optical paths and said providing of one or more output optical paths comprise removing material from said block of material, said optical paths being where said material has been removed;

providing a first sensor to receive light from said output optical path and generate therefrom a signal indicative of the angle at which light specularly reflects off said workpiece.

25. Method of claim 24 further comprising:

providing a second optical output path extending through said block of material; and

providing a second sensor for receiving light from said second optical output path and generating therefrom a signal indicative of the amount of light that scatters off the workpiece surface at a predetermined range of angles.

26. Apparatus of comprising:

a block of material having a plurality of optical paths extending therethrough;

at least one of said optical paths comprising an input optical path for communicating laser light from a laser light source to a workpiece being inspected; and

at least one of said optical paths comprising an output optical path for communicating light reflected from said workpiece to a detector, said block of material moving relative to said workpiece during use; and

one or more mirrors affixed to said block for reflecting light in at least one of said optical paths.

27. Apparatus comprising:

a block of material having a plurality of optical paths extending therethrough;

at least one of said optical paths comprising an input optical path for communicating laser light from a laser light source to a workpiece being inspected;

at least one of said optical paths comprising an output optical path for communicating light reflected from said workpiece to a detector;

means for causing relative movement between said block of material and said workpiece during use;

wherein said material is not present in said optical paths.

28. A method for using an optical test head comprising:

providing a block of material having at least one input optical path extending therethrough and at least one output optical path extending therethrough, wherein said material is not present in said optical paths;

transmitting laser light through said input optical path to a workpiece;

receiving light reflected from said workpiece into said one or more output optical paths and transmitting said received light to a detector; and

causing relative motion of said workpiece relative to said block during said transmitting and receiving.

29. Method of claim 28 wherein said workpiece is a platter and said transmitting of laser light through said input optical path comprises transmitting laser light through one or more lenses, said method also comprising passing said reflected light through one or more lenses, said one or more lenses being within said block of material.

30. Method of claim 28 wherein said block of material is opaque.

31. Method of claim 28 wherein said workpiece is a platter.

32. Method of claim 28 wherein said workpiece is located outside of said block of material, said light leaving said block of material to said workpiece and then reflecting back from said workpiece to said block of material prior to said receiving.

33. Method of claim 28 wherein said detector generates a signal indicative of the angle at which light specularly reflects off said workpiece.

34. Method of claim 33 wherein said a second detector receives light scattered from said workpiece via a second output optical path extending through said block of material, said second detector generating a signal indicative of the amount of light that scatters off the workpiece surface at a predetermined range of angles.

35. Method of claim 28 wherein a mirror is affixed to said block of material, said method further comprising reflecting said laser light off of said mirror.

36. Method of claim 28 further comprising passing said laser light through a lens that concentrates light directly onto said workpiece.

Assignments (8)