Computer based semi-automatic focusing and assembly apparatus and method

• US 6,399,937 B1
• Filed: 08/08/2000
• Issued: 06/04/2002
• Est. Priority Date: 02/12/1998
• Status: Expired due to Fees

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: The Research Foundation for The State University of New York (State University of New York)
• Inventors: Huang, Peisen S., Kao, Imin
• Primary Examiner(s): ALLEN, STEPHONE B
• Application Number:
  US09/601,822
• Time in Patent Office: 665 Days
• Field of Search: 250/201.2, 250/201.4, 250/216, 362/235, 362/240, 362/277, 362/317, 362/319, 356/400
• US Class Current: 250/216
• CPC Class Codes: G06K 7/10811 Focalisation

Abstract

An apparatus and method for semi-automatic focusing and assembling of a light beam modifier, such as a lens, relative to a light beam source to optimize the light beam characteristics at one or more locations along the beam path using one or more light beam analyzers (27, 28, 29). A host computer compares the measurements and axially adjusts the light beam modifier. The apparatus may include two focusing stations (21, 22) for alternately focusing and assembling two light source assemblies, two beam splitters (25, 26) for splitting the light beam emitted from either focusing station into three components, and three light beam analyzers for measuring the beam characteristics at three locations. The apparatus may also include a video camera for automated or manual pointing of the laser beam, a semi-automatic glue dispensing system for fixing the light beam modifier relative to the light source and an automatic laser power-up circuit.

Claims

1. An apparatus for positioning a light beam modifier relative to a light beam source to optimize a beam characteristic at one or more desired locations along the path of a beam comprising:

a light source for emitting a first light beam along a first beam path;

a first light beam analyzer positioned at a first desired location along said first beam path for continuously measuring a characteristic of said first light beam emitted from said light source and generating a value signal based on said measurement;

a first light beam modifier axially aligned along said first beam path between said light source and said first light beam analyzer, said first light beam modifier being movable along said first beam path relative to said light source; and

a host computer electrically connected to said first light beam analyzer and said first light beam modifier, said host computer receiving said value signal and generating a focusing signal for axially adjusting said first light beam modifier along said beam path to provide an optimal beam characteristic at said first location.

2. The apparatus as defined in claim 1, wherein said light beam modifier is an optical focusing lens.

3. The apparatus as defined in claim 1, wherein said light source is a laser emitting diode.

4. The apparatus as defined in claim 1, wherein said measured beam characteristic is a beam width.

5. The apparatus as defined in claim 1, further comprising a first focusing fixture for holding said light source and said light beam modifier in axial alignment, said focusing fixture being adjustable to point said first light beam emitted from said light source at said first light beam analyzer.

6. The apparatus as defined in claim 5, wherein said first focusing fixture includes a first focusing motor electrically connected to said host computer for axially adjusting said light beam modifier along said beam path.

7. The apparatus as defined in claim 6, wherein said host computer generates said focusing signal based on a difference between said value signal and a predetermined parameter range associated with said first location, said focusing signal activating said focusing motor to axially adjust said light beam modifier with respect to said light source, said focusing signal terminating when said value signal falls within said predetermined parameter range.

8. The apparatus as defined in claim 6, wherein said first focusing fixture includes a drive member for holding said light beam modifier, said drive member being driven by said first focusing motor for axially adjusting said light beam modifier along said beam path.

9. The apparatus as defined in claim 1, further comprising a first carrier rail axially aligned with said first beam path and wherein said first light beam analyzer is slidably mounted to said first carrier rail for positioning and fixing said first light beam analyzer at said first desired location.

10. The apparatus as defined in claim 1, further comprising:

a first beam splitter positioned along the axis of said first beam path between said light beam modifier and said first light beam analyzer, said first beam splitter splitting said first light beam into a first component and a second component, a characteristic of said first component being continuously measured by said first light beam analyzer; and

a second light beam analyzer electrically connected to said host computer and positioned at a second desired location along a path of said second component for continuously measuring a characteristic of said second component and generating a value signal based on said measurement,

wherein said host computer receives said value signals from said first and second light beam analyzers and generates a focusing signal based on differences between said value signals and respective predetermined parameter ranges associated with said first and second locations to provide optimal beam characteristics at said first and second locations.

11. The apparatus as defined in claim 10, further comprising:

a first carrier rail axially aligned with said first component of said light beam; and

a second carrier rail axially aligned with said second component of said light beam,

wherein said first light beam analyzer is slidably mounted to said first carrier rail for positioning and fixing said first light beam analyzer at said first desired location and said second light beam analyzer is slidably mounted to said second carrier rail for positioning and fixing said second light beam analyzer at said second desired location.

12. The apparatus as defined in claim 10, further comprising:

a second beam splitter positioned along said path of said second component of said light beam between said first beam splitter and said second light beam analyzer, said second beam splitter splitting from said second component a third component of said light beam; and

a third light beam analyzer electrically connected to said host computer and positioned at a third desired location along a path of said third component for continuously measuring a characteristic of said third component of said light beam and generating a value signal based on said measurement,

wherein said host computer receives said value signals from said first, second and third light beam analyzers and generates a focusing signal based on differences between said value signals and respective predetermined parameter ranges associated with said first, second and third locations to provide optimal beam characteristics at said first, second and third locations.

13. The apparatus as defined in claim 12, further comprising:

a first carrier rail axially aligned with said first component of said light beam;

a second carrier rail axially aligned with said second component of said light beam; and

,

a carrier slidably mounted to said second carrier rail,

wherein said first light beam analyzer is slidably mounted to said first carrier rail for positioning and fixing said first light beam analyzer at said first desired location and said second light beam analyzer is slidably mounted to said second carrier rail for positioning and fixing said second light beam analyzer at said second desired location and said third light beam analyzer and said second beam splitter are fixed on said carrier for positioning and fixing said third light beam analyzer at said third desired location.

14. The apparatus as defined in claim 1, further comprising:

a second light source positioned for emitting a second light beam along a second beam path;

a first beam splitter positioned along the axes of said first and second beam paths between said first light beam modifier and said first light beam analyzer, said first beam splitter splitting each of said first and second light beams into first and second components, a characteristic of said first components being continuously measured by said first light beam analyzer; and

a second light beam modifier electrically connected to said host computer and axially aligned along said second beam path between said second light source and said first beam splitter, said second light beam modifier being movable along said second beam path relative to said second light source;

wherein said first light beam analyzer generates value signals based on said measurements of said first components and wherein said host computer receives said value signals and generates focusing signals for axially adjusting said first and second light beam modifiers.

15. The apparatus as defined in claim 14, further comprising:

a second light beam analyzer electrically connected to said host computer and positioned at a second desired location along a path of said second components for continuously measuring a characteristic of said second components and generating value signals based on said measurement,

wherein said host computer receives said value signals from said first and second light beam analyzers and generates focusing signals based on differences between said value signals and respective predetermined parameter ranges associated with said first and second locations for axially adjusting said first and second light beam modifiers.

16. The apparatus as defined in claim 14, further comprising a second focusing fixture for holding said second light source and said second light beam modifier in axial alignment, said second focusing fixture being adjustable to point said second light beam at said first beam splitter.

17. The apparatus as defined in claim 16, wherein said second focusing fixture includes a second focusing motor electrically connected to said host computer for axially adjusting said second light beam modifier along said second beam path.

18. The apparatus as defined in claim 15, further comprising:

a second beam splitter positioned along the axes of said second components of said light beams between said first beam splitter and said second light beam analyzer, said second beam splitter splitting from each of said second components a third component; and

a third light beam analyzer electrically connected to said host computer and positioned at a third desired location along a path of said third components of said light beams for continuously measuring a characteristic of said third components and generating value signals based on said measurement,

wherein said host computer receives said value signals from said first, second and third light beam analyzers and generates focusing signals based on differences between said value signals and respective predetermined parameter ranges associated with said first, second and third locations for axially adjusting said first and second light beam modifiers.

19. The apparatus as defined in claim 1, further comprising:

a video camera electrically connected to said host computer and positioned adjacent said first light beam analyzer for capturing an image of said light beam falling on said first beam light analyzer; and

wherein said host computer includes a video monitor for displaying the image captured by said video camera.

20. The apparatus as defined in claim 19, wherein said host computer digitizes the image captured by the video camera and displays the digitized image on said video monitor.

21. The apparatus as defined in claim 20, wherein said host computer further provides a reference target and displays said reference target along with said digitized image on said video monitor for visually assisting an operator in pointing the light source beam.

22. The apparatus as defined in claim 5, further comprising:

an adjustment motor electrically connected to said host computer and positioned adjacent said first focusing fixture for adjusting the direction of said light beam; and

a video camera electrically connected to said host computer and positioned adjacent said first light beam analyzer for capturing an image of said light beam falling on said first light beam analyzer,

wherein said host computer includes a frame grabber for digitizing the image captured by the video camera and for detecting the location of said light beam on said first light beam analyzer and an algorithm for generating an adjustment signal based on the difference between the detected light beam location and a predetermined location, said adjustment signal activating said adjustment motor to adjust the direction of said light beam, said adjustment signal terminating when the detected light beam location is within the predetermined location.

23. The apparatus as defined in claim 1, further comprising a light source power circuit electrically connected to said host computer and said light source for providing controlled power to said light source.

24. The apparatus as defined in claim 23, wherein said light source power circuit comprises a current monitoring circuit operatively coupled to said light source for monitoring a current flowing through said light source and generating an output signal corresponding to said monitored current, and a power control circuit operatively coupled to said light source for controlling power to said light source in response to said output signal.

25. The apparatus as defined in claim 6, wherein said first focusing motor includes an optical limit switch which prevents axial adjustment of said light beam modifier beyond a predetermined distance by terminating power to said motor when said predetermined distance is exceeded.

26. The apparatus as defined in claim 1, further comprising a glue dispenser electrically connected to said host computer for dispensing glue to said light beam modifier and said light source when said focusing signal from said host computer terminates.

27. The apparatus as defined in claim 26, wherein said glue dispenser includes a valve electrically connected to said host computer, said valve being controlled by said host computer to dispense a predetermined amount of glue.

28. The apparatus as defined in claim 27, wherein said glue dispenser generates a curing signal when the glue is dispensed, said host computer receiving said curing signal and initiating a timer, said timer alerting an operator when the glue has cured.

29. A method for optimizing a characteristic of a light beam emitted from a light source at one or more desired locations along the path of said light beam, said method comprising the steps of:

positioning a light beam modifier along said light beam path in axial alignment with said beam at a distance from said light beam source for optimizing a characteristic of said beam;

continuously measuring a characteristic of said light beam at at least one selected position along said beam path;

generating value signals corresponding to said continuously measured characteristic;

comparing said value signals with a predetermined value range corresponding to an optimal beam characteristic;

generating a focusing signal which corresponds to an adjustment of said modifier to optimize said beam characteristic at said selected position;

sending said focusing signal to said modifier;

axially adjusting said light beam modifier along said beam path based on said focusing signal; and

terminating said focusing signal when said value signals fall within said predetermined value range.

30. The method as defined in claim 29, wherein said light beam modifier is an optical focusing lens.

31. The method as defined in claim 29, wherein said light source is a laser emitting diode.

32. The method as defined in claim 29, wherein said measured beam characteristic is a beam width.

33. The method as defined in claim 29, further comprising the step of fixing said light beam modifier with respect to said light source when said focusing signal terminates.

34. The method as defined in claim 29, further comprising the steps of:

positioning at least one beam splitter along the axis of said beam path for splitting from said light beam one or more components; and

continuously measuring a characteristic of said one or more components at a selected position along the path of said components;

generating value signals corresponding to said continuously measured characteristics of said components; and

comparing said value signals with a predetermined value range corresponding to an optimal beam characteristic.

35. The method as defined in claim 29, further comprising the steps of:

displaying a video image of said light beam along with a reference target corresponding to said at least one selected measurement position along said beam path; and

adjusting said light beam path based on said displayed video image and said reference target.