Wedge-shaped lensless laser focusing device

• US 6,731,421 B2
• Filed: 04/19/2002
• Issued: 05/04/2004
• Est. Priority Date: 04/23/2001
• Status: Expired due to Fees

• Current Assignee: Dee E. Willden
• Original Assignee: Dee E. Willden
• Inventors: Willden, Dee E.
• Primary Examiner(s): Dunn, Drew
• Assistant Examiner(s): Pritchett, Joshua L
• Application Number:
  US10/126,908
• Publication Number:
  US 20020154424A1
• Time in Patent Office: 746 Days
• Field of Search: 359/227, 359/232, 359/234, 359/856, 359/857
• US Class Current: 359/234
• CPC Class Codes: B01D 59/34 Separation by photochemical methods
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 27/0983 being curved

Abstract

A lensless focusing device for receiving an unfocused laser beam and creating a desired output pattern of laser profiles. The focusing device includes a pair of wedge plates oriented at a reflective angle relative to the projection axis of the input laser beam. The focusing device generates an output pattern having a plurality of spaced laser profiles. The laser profiles include a series of fixed laser profiles and a series of adjustable laser profiles. Rotation of the focusing device about the projection axis of the input laser beam moves the adjustable laser profiles relative to the fixed laser profiles. Multiple focusing devices can be used in series with each other to generate an output pattern having a grid shape in which points on the grid are movable upon rotation of either focusing device.

Claims

1. An apparatus for focusing an input laser beam projected along a projection axis, the apparatus comprising:

a first wedge plate extending from an inlet end to a discharge end, the first wedge plate being positioned at a reflection angle relative to the projection axis of the input laser beam; and

a second wedge plate extending from an inlet end to a discharge end, the second wedge plate being positioned at the reflection angle relative to the projection axis in a direction opposite the first wedge plate,

wherein the inlet end of the first wedge plate and the inlet end of the second wedge plate are separated by an inlet opening and the discharge end of the first wedge plate and the discharge end of the second wedge plate are separated by a discharge opening, wherein the width of the inlet opening is greater than the width of the input laser beam and the width of the discharge opening is less than the width of the input laser beam,

wherein the first wedge plate and the second wedge plate are rotatable about the projection axis and maintain the reflection angle between the first and second wedge plates and the projection axis during said rotation, wherein rotation about the projection axis adjusts the output pattern of the focusing device.

2. The apparatus of claim 1 wherein both the first wedge plate and the second wedge plate include a polished face surface, wherein the first and second wedge plates are positioned such that the input laser beam contacts and is reflected off of the polished face surface on each of the first and second wedge plates.

3. The apparatus of claim 1 wherein the first and second wedge plates are formed from a metallic material.

4. The apparatus of claim 1 wherein the first wedge plate is connected to the second wedge plate such that the first wedge plate and the second wedge plate rotate in unison about the projection axis.

5. The apparatus of claim 1 wherein the distance between the inlet end of the first wedge plate and the inlet end of the second wedge plate is adjustable.

6. A method of creating an output pattern from an unfocused laser beam being projected along a projection axis, the method comprising the steps of:

positioning a first wedge plate at a reflection angle relative to the projection axis, the first wedge plate including a face surface extending from an inlet end to a discharge end;

positioning a second wedge plate at the reflection angle relative to the projection axis, the second wedge plate extending in an opposite direction relative to the first wedge plate, the second wedge plate including a face surface extending from an inlet end to a discharge end;

positioning the first wedge plate relative to the second wedge plate to define an inlet opening between the inlet ends of the first and second wedge plates and a discharge opening between the discharge ends of the first and second wedge plates;

positioning the first and second wedge plates along the projection axis such that the input laser beam is received within the inlet opening, wherein the input laser beam is reflected off of the face surfaces and out of the discharge opening to define the output pattern; and

simultaneously rotating the first and second wedge plates about the projection axis while maintaining the reflection angle of both the first and second wedge plates relative to the projection axis to adjust the spacing between the plurality of spaced laser profiles.

7. The method of claim 6 wherein the output pattern includes a plurality of spaced laser profiles.

8. The method of claim 7 wherein the output pattern includes a plurality of fixed laser profiles and a plurality of adjustable laser profiles.

9. The method of claim 8 wherein the step of simultaneously rotating the first and second wedge plates about the projection axis moves the adjustable laser profiles relative to the fixed laser profiles.

10. The method of claim 6 wherein the face surfaces of both the first wedge plate and the second wedge plate are polished.

11. The method of claim 6 wherein the width of the inlet opening is greater than the width of the input laser beam and the width of the discharge opening is less than the width of the input laser beam.

12. The method of claim 6 wherein both the first wedge plate and the second wedge plate are formed from a metallic material.

13. A method of creating an output pattern from an unfocused laser beam being projected along a projection axis, the method comprising the steps of:

positioning a first focusing device along the projection axis, the first focusing device having an inlet opening and a discharge opening, wherein the first focusing device receives the input laser beam through the input opening and creates a first output pattern from the discharge opening;

positioning a second focusing device along the projection axis, the second focusing device being rotated 90°

about the projection axis relative to the first focusing device and positioned to receive the first output pattern from the first focusing device, wherein the second focusing device generates a second output pattern including a plurality of spaced laser profiles;

selectively rotating the first focusing device about the projection axis to adjust the spacing between the plurality of spaced laser profiles; and

selectively rotating the second focusing device about the projecting axis to adjust the spacing between the plurality of spaced laser profiles.

14. The method of claim 13 wherein the first focusing device and the second focusing device each comprise:

a first wedge plate having a face surface extending from an inlet end to a discharge end, the first wedge plate being positioned at a reflection angle relative to the projection axis;

a second wedge plate having a face surface extending from an inlet end to a discharge end, the second wedge plate being positioned at the reflection angle relative to the projection axis and opposite the first wedge plate,

wherein the distance between the inlet end of the first wedge plate and the inlet end of the second wedge plate define the inlet opening and the distance between the discharge end of the first wedge plate and the discharge end of the second wedge plate define the discharge opening.

15. The method of claim 14 wherein the width of the inlet opening is greater than the width of the input laser beam and the width of the discharge opening is less than the width of the input laser beam.

16. The method of claim 14 wherein the first wedge plate and the second wedge plate of both the first focusing device and the second focusing device include a polished face surface.