Tilted primary clamshell lens laser scanner

• US 5,903,386 A
• Filed: 01/20/1998
• Issued: 05/11/1999
• Est. Priority Date: 01/20/1998
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Hall, James Timothy, Rose, Dennis Hilliard, Mantravadi, Murty Venkata, Richman, Dennis Carl
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US09/009,321
• Time in Patent Office: 476 Days
• Field of Search: 359/366, 359/365, 359/850, 359/853, 359/856, 359/859, 359/867
• US Class Current: 359/366
• CPC Class Codes: G02B 17/0816 off-axis or unobscured systems in which not all of the mirrors share a common axis of rotational symmetry, e.g. at least one of the mirrors is warped, tilted or decentered with respect to the other elements
• CPC Class Codes: G02B 17/086 wherein the system is made of a single block of optical material, e.g. solid catadioptric systems
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 19/009 for use with infrared radiation
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence

Abstract

A scanner transmits a generally collimated beam of radiation such that the beam rotates about an axis to form a conical scanning pattern. The scanner comprises a concave parabolic reflector having a geometric axis and a focus, a rotation mechanism for effecting rotation of the concave parabolic reflector about a rotation axis which is angularly offset with respect to the geometric axis of the concave parabolic reflector, an opening formed in the concave parabolic reflector proximate the rotation axis thereof, and a convex parabolic reflector disposed along the rotation axis of the concave parabolic reflector and having a focus which is approximately co-located with the focus of the concave parabolic reflector. Directing collimated radiation through the opening formed in the concave parabolic reflector and onto the convex parabolic reflector while rotating the concave parabolic reflector about the rotation axis thereof effects transmission of a generally collimated beam of radiation such that the beam rotates about the rotation axis so as to form a conical scanning pattern.

Claims

1. A scanner for transmitting a generally collimated beam of radiation such that the beam rotates about an axis to form a conical scanning pattern, the scanner comprising:

a) a concave parabolic reflector having a geometric axis and a focus;

b) a rotation mechanism for effecting rotation of the concave parabolic reflector about a rotation axis which is angularly offset with respect to the geometric axis of the concave parabolic reflector;

c) an opening formed in the concave parabolic reflector near the rotation axis thereof;

d) a convex parabolic reflector disposed along the rotation axis of the concave parabolic reflector and having a focus which is approximately co-located with the focus of the concave parabolic reflector; and

e) a collimating lens disposed at the opening formed in the concave parabolic reflector directing collimated radiation through the opening formed in the concave parabolic reflector and onto the convex parabolic reflector while rotating the concave parabolic reflector about the rotation axis thereof effects transmission of a generally collimated beam of radiation such that the beam rotates about the rotation axis so as to form a conical scanning pattern.

2. The scanner as recited in claim 1, wherein the rotation axis is offset with respect to the geometric axis by an angle of between approximately 7 degrees and approximately 10 degrees.

3. The scanner as recited in claim 1, wherein the rotation axis is offset with respect to the geometric axis by an angle of approximately 8.5 degrees.

4. The scanner as recited in claim 1, wherein the convex parabolic reflector and the concave parabolic reflector are configured to reflect optical radiation.

5. The scanner as recited in claim 1, wherein the concave parabolic reflector comprises a dynamically balanced concave parabolic reflector so as to facilitate rotation thereof.

6. The scanner as recited in claim 1, further comprising a collimating lens for collimating an output from a diode laser prior to the output being incident upon the convex parabolic reflector.

7. The scanner as recited in claim 1, further comprising a motor in mechanical communication with the concave parabolic reflector for effecting rotation thereof.

8. The scanner as recited in claim 1, further comprising a transparent window upon which the convex parabolic reflector is mounted.

9. A lidar system having a scanner for transmitting a generally collimated beam of radiation such that the beam rotates about an axis to form a conical scanning pattern, the scanner comprising:

a) a concave parabolic reflector having a geometric axis and a focus;

b) a rotation mechanism for effecting rotation of the concave parabolic reflector about a rotation axis which is angularly offset with respect to the geometric axis of the concave parabolic reflector;

c) an opening formed in the concave parabolic reflector near the rotation axis thereof;

d) a convex parabolic reflector disposed along the rotation axis of the concave parabolic reflector and having a focus which is approximately co-located with the focus of the concave parabolic reflector; and

e) a collimating lens disposed at the opening formed in the concave parabolic reflector directing collimated radiation through the opening formed in the concave parabolic reflector and onto the convex parabolic reflector while rotating the concave parabolic reflector about the rotation axis thereof effects transmission of a generally collimated beam of radiation such that the beam rotates about the rotation axis so as to form a conical scanning pattern.