Laser beam flying spot scanner

Claim 2

An optical scanning system for causing a substantially collimated input laser beam to peRform an angular scan comprising: optical imaging means on a system optical axis; means for directing said input beam to said imaging means on a secondary axis substantially parallel to said system axis but displaced therefrom to form a beam focus at the back focal plane of said imaging means; and scanning means comprising: mirror means including a pair of reflective surfaces arranged convergent in the direction of propagation of said beam, the line of intersection of said reflective surfaces lying in a plane defined by said system optical axis and said secondary axis, and transport means for moving said mirror pair transversely through said beam in the vicinity of said beam focus in a direction orthogonal to said line of intersection of said mirror surfaces to cause an image of said beam focus to move relative to said beam focus, said mirror means reflecting light from said beam focus back to said imaging means on the opposite side of said system optical axis from said input beam to form a substantially collimated angularly sweeping output beam.

Claim 3

The system defined by claim 1 wherein said optical imaging means comprises a positive power reflector.

Claim 4

The system defined by claim 2 wherein the reflective surface of said positive power reflector is parabolic.

Claim 5

An optical scanning system for flying spot recording or displaying a signal in a two-dimensional raster, comprising: laser means for generating an input laser beam; light modulating means in said input beam for modulating said beam according to a time-varying signal supplied to said modulating means; spot-forming imaging means for focusing said input beam to a spot; spot-collecting imaging means located substantially a focal length away from said spot for collecting light emanating from said spot; line-scanning means located substantially at the focal plane of said spot-collecting imaging means at which said spot is formed, said scanning means receiving radiation from said spot to cause an image of said spot to move substantially in the focal plane of said spot-collecting imaging means, whereby an angularly sweeping beam is produced at the output of said spot-collecting imaging means; line-forming imaging means receiving said angularly sweeping beam and forming substantially at the back focal plane thereof a line representing a one-dimensionally moving image of said spot; raster-scanning means located substantially at said back focal plane of said line-forming imaging means for causing an image of said line to move in a direction perpendicular to its length to form a two-dimensional raster and for reflecting light back to said line-forming imaging means to produce a substantially collimated output beam making a repetitive two-dimensional scan; and imaging means receiving said output beam for forming a two-dimensional raster exhibiting information carried by said signal.

Claim 6

An optical scanning system for flying spot recording or displaying a signal in a two-dimensional raster, comprising: laser means for generating an input laser beam; light modulating means in said input beam for modulating said beam according to a time-varying signal supplied to said modulating means; spot-forming imaging means for focusing said input beam to a spot; spot-collecting imaging means located substantially a focal length away from said spot for collecting light emanating from said spot; line-scanning means located substantially at the focal plane of said spot-collecting imaging means at which said spot is formed, said scanning means receiving radiation from said spot to cause an image of said spot to move substantially in the focal plane of said spot-collecting imaging means, whereby an angularly sweeping beam is produced at the output of said spot-collecting imaging means; line-forming imaging means receiving said angularly sweeping beam and forming substantially at the back focal plane thereof a line representing a one-dimensionally moving image of said spot; raster-scanning means located substantially at said back focal plane of said line-forming imaging means for causing an image of said line to move in a direction perpendicular to its length to form a two-dimensional raster and for reflecting light back to said line-forming imaging means to produce a substantially collimated output beam making a repetitive two-dimensional scan; and imaging means receiving said output beam for forming a two-dimensional raster exhibiting information carried by said signal.

Claim 7

The system defined by claim 4 wherein said line and raster scanning means comprise respective trains of corner mirror pairs arranged convergent in the direction of propagation of incident radiation and means for effectively transporting said mirror trains in orthogonal directions.

Claim 8

An optical scanning system for flying spot recording or displaying a signal in a two-dimensional raster, laser means for generating an input laser beam; light modulating means in said input beam for modulating said beam according to a time-varying signal supplied to said modulating means; spot-forming imaging means for focusing said input beam to a spot on a system optical axis; spot-collecting imaging means located on said optical axis substantially a focal distance away from said spot for collecting light emanating from said spot; spot-translating means comprising: first mirror means including a first pair of mirror surfaces arranged convergent in the direction of propagation of said beam, and transport means for moving said first miRror surface pair transversely through said beam in the vicinity of said spot in a direction orthogonal to the line of intersection of said mirror surfaces to cause an image of said spot to move relative to said spot, said mirror surface pair reflecting light from said spot to said spot-collecting imaging means to form an angularly sweeping beam at the output of said spot-collecting imaging means, line-forming imaging means on said optical axis receiving said angularly sweeping beam for forming at the back focal plane thereof a line representing a one-dimensionally moving image of said spot; raster-scanning means for causing an image of said line to move perpendicular to the direction thereof to form a two-dimensional raster, comprising: second mirror means including a second pair of mirror surfaces arranged convergent in the direction of propagation of said line-forming beam, and transport means for moving said second mirror surface pair transversely through said line-forming beam in the vicinity of said line in a direction orthogonal to the line of intersection of said second pair of mirror surfaces and substantially orthogonal to the direction of said line to effectively cause an image of said line to move relative to said line so as to form a raster, said mirror pair reflecting the light defining said raster back to said line-imaging means to form a substantially collimated output beam making a repetitive two-dimensional scan; and imaging means receiving said output beam for forming a two-dimensional raster exhibiting information carried by said signal.

Claim 9

An optical scanning system for flying spot recording or displaying a signal in a two-dimensional raster, laser means for generating an input laser beam; light modulating means in said input beam for modulating said beam according to a time-varying signal supplied to said modulating means; spot-forming imaging means for focusing said input beam to a spot on a system optical axis; spot-collecting imaging means located on said optical axis substantially a focal distance away from said spot for collecting light emanating from said spot; spot-translating means comprising: first mirror means including a first pair of mirror surfaces arranged convergent in the direction of propagation of said beam, and transport means for moving said first miRror surface pair transversely through said beam in the vicinity of said spot in a direction orthogonal to the line of intersection of said mirror surfaces to cause an image of said spot to move relative to said spot, said mirror surface pair reflecting light from said spot to said spot-collecting imaging means to form an angularly sweeping beam at the output of said spot-collecting imaging means, line-forming imaging means on said optical axis receiving said angularly sweeping beam for forming at the back focal plane thereof a line representing a one-dimensionally moving image of said spot; raster-scanning means for causing an image of said line to move perpendicular to the direction thereof to form a two-dimensional raster, comprising: second mirror means including a second pair of mirror surfaces arranged convergent in the direction of propagation of said line-forming beam, and transport means for moving said second mirror surface pair transversely through said line-forming beam in the vicinity of said line in a direction orthogonal to the line of intersection of said second pair of mirror surfaces and substantially orthogonal to the direction of said line to effectively cause an image of said line to move relative to said line so as to form a raster, said mirror pair reflecting the light defining said raster back to said line-imaging means to form a substantially collimated output beam making a repetitive two-dimensional scan; and imaging means receiving said output beam for forming a two-dimensional raster exhibiting information carried by said signal.

Claim 10

The system defined by claim 6 wherein said spot-forming imaging means comprises an objective lens, and wherein said spot-collecting imaging means and said spot-forming imaging means comprise a telecentric set.

Claim 11

The system defined by claim 7 wherein said spot-collecting imaging means and said line-forming imaging means comprise a symmetrical arrangement of reverse Steinheil doublets.

Claim 12

The system defined by claim 6 wherein said spot-forming imaging means and said spot-collecting imaging means comprise the same structure performing both stated functions, and wherein said system includes means for directing said input light beam to this double-function means on a secondary axis parallel to said system axis but spaced therefrom, said line of intersection of said first mirror pair lying in a plane defined by said system optical axis and said secondary axis diametrically opposed first and second quadrants of said double-function imaging means being employed to form said spot and to collect light from said spot.

Claim 13

The apparatus defined by claim 9 wherein said double-function imaging means includes a positive power mirror.

Claim 14

The apparatus defined by claim 9 wherein said double-function imaging means and said line-imaging means constitute the same structure, and wherein said system includes means for reflecting said light returned from said second quadrant of said double-function spot-imaging and spot-collecting means and reflecting it back to a third quadrant of said structure, said raster scanning means being located contiguous to said system axis effectively adjacent said line-scanning means for receiving said beam from said third quadrant of said structure and reflecting it back to a fourth quadrant of said structure.