LASER SCANNER WITH PERIPHERAL SCANNING CAPABILITY

• US 20040114205A1
• Filed: 12/05/2002
• Published: 06/17/2004
• Est. Priority Date: 12/05/2002
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Richman, Dennis C., Raffensperger, Susan
• Granted Patent: US 6,879,419 B2
• Time in Patent Office: Days
• US Class Current: 359/205
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces

Abstract

The present invention relates generally to ladar and more particularly to a tilted primary clamshell lens laser scanner for transmitting a generally collimated beam of radiation at a first frequency such that the beam rotates about a central axis so as to form a conical scanning pattern suitable for lidar applications. In addition, the ladar includes a system for transmitting at least one additional collimated beam of radiation at a second frequency at a wider angle then the first collimated beam.

Claims

1. A scanner for transmitting at least two generally collimated beams of radiation of different frequencies such that the beams rotates about an axis to form a conical scanning pattern, the scanner comprising:

a housing;

a frame member rotatably mounted within said housing having an axis of rotation;

motor for rotating said frame member about said axis of rotation;

a concave parabolic first reflector having a geometric axis and a focus mounted to said frame member with said geometric axis angularly offset from said axis of rotation, said first reflector having an opening near said axis of rotation;

a convex parabolic second reflector mounted to said frame assembly disposed along the rotation axis of said reflector and having a focus which is approximately co-located with the focus of said first reflector, said second reflector adapted to transmit at least one of the collimated beam of radiation and to reflect at least one collimated of radiation;

a collimating lens disposed at said opening formed in said first reflector directing the at least two collimated beams of radiation through said opening formed in said first reflector and onto said second reflector;

means for diffracting the at least one collimated beam of radiation transmitted through said second reflector outward from said axis of rotation such that as said frame assembly rotates the at least one beam of radiation transmitted through said second reflector is transmitted in a conical pattern.

2. The scanner as recited in claim 1 wherein said means comprises:

a prism mounted behind said second reflector co-incident therewith and mounted to said frame member, said prism for diffracting the at least one collimated beam of radiation transmitted through said second reflector; and

a mirror mounted behind said prism for reflecting said at least one collimated beam of radiation diffracted by said prism radically outward from said axis of rotation to said diffraction means. and

diffraction grating mounted on said housing and extending about said axis of rotation for diffracting the at least one collimated beam of radiation reflected from said mirror.

3. The scanner as recited in claim 1 wherein said means comprises a diffraction grating mounted to said second reflector for diffracting the at least one collimated beam of radiation transmitted through said second reflector.

4. The scanner as set forth in claim 3 comprising:

said first reflector adapted to reflect at least two beams of collimated radiation to said second reflector; and

a second diffraction grating located in said frame assembly adapted to refract the at least two beams of collimated ration reflected off said second reflector.

5. A scanner for transmitting at least two generally collimated beams of radiation of different frequencies such that the beams rotates about an axis to form a conical scanning pattern, the scanner comprising:

a housing;

a frame member rotatably mounted within said housing having an axis of rotation;

motor for rotating said frame member about said axis of rotation;

a concave parabolic first reflector having a geometric axis and a focus mounted to said frame member with said geometric axis angularly offset from said axis of rotation, said first reflector having an opening near said axis of rotation;

a convex parabolic second reflector mounted to said frame assembly disposed along the rotation axis of said reflector and having a focus which is approximately co-located with the focus of said first reflector, said second reflector adapted to transmit at least one of the collimated beam of radiation and to reflect at least one collimated of radiation;

a collimating lens disposed at said opening formed in said first reflector directing the at least two collimated beams of radiation through said opening formed in said first reflector and onto said second reflector;

a prism mounted behind said second reflector co-incident therewith and mounted to said frame member, said prism for diffracting the at least one collimated beam of radiation transmitted through said second reflector; and

a mirror mounted behind said prism for reflecting said at least one collimated beam of radiation diffracted by said prism radically outward from said axis of rotation to said diffraction means. and

diffraction grating mounted on said housing and extending about said axis of rotation for diffracting the at least one collimated beam of radiation reflected from said mirror.

6. A scanner for transmitting at least two generally collimated beams of radiation of different frequencies such that the beams rotates about an axis to form a conical scanning pattern, the scanner comprising:

a housing;

a frame member rotatably mounted within said housing having an axis of rotation;

motor for rotating said frame member about said axis of rotation;

a concave parabolic first reflector having a geometric axis and a focus mounted to said frame member with said geometric axis angularly offset from said axis of rotation, said first reflector having an opening near said axis of rotation;

a convex parabolic second reflector mounted to said frame assembly disposed along the rotation axis of said reflector and having a focus which is approximately co-located with the focus of said first reflector, said second reflector adapted to transmit at least one of the collimated beam of radiation and to reflect at least one collimated of radiation;

a collimating lens disposed at said opening formed in said first reflector directing the at least two collimated beams of radiation through said opening formed in said first reflector and onto said second reflector; and

a diffraction grating mounted to said second reflector for diffracting the at least one collimated beam of radiation transmitted through said second reflector.

7. The scanner as set forth in claim 6 comprising:

said first reflector adapted to reflect at least two beams of collimated radiation to said second reflector; and

a second diffraction grating located in said frame assembly adapted to refract the at least two beams of collimated ration reflected off said second reflector.