Apparatus with two input beams for generating optical scans

Claim 2

An optical scanner for receiving an input beam and for generating an optical output beam which repetitively scans a fixed path comprising: a. means for converting a single input beam into alternating upper and lower input beams; b. a first mirror repetitively rotated through an angle about a vertically oriented first axis for receiving the upper input beam and for repetitively generating a first scan; c. a second mirror repetitively rotated through an angle about the first axis for receiving the lower input beam and for repetitively generating a second scan, said first and second mirrors having a relative phase angle greater than zero and random facet to axis errors; d. first means for redirecting the first scan back onto the first mirror to form a first redirected scan, wherein the first redirected scan is reflected from the first mirror to generate a plurality of first output scans which define a family of non-coincident surfaces, said family of surfaces being non-intersecting with respect to the upper input beam, the first redirected scan being vertically displaced from the first scan by a distance related to the mirror facet to axis error and laterally displaced from the first scan by a distance related to the relative angle between the mirror and the upper input beam; e. second means for redirecting the second scan back onto the second mirror to form a second redirected scan, wherein the second redirected scan is reflected from the second mirror to generate a plurality of second output scans which define a family of non-coincident surfaces, said family of surfaces being non-intersecting with respect to the lower input beam; the second redirected scan being vertically displaced from the second scan by a distance related to the mirror facet to axis error and laterally displaced from the second scan by a distance related to the relative angle between the mirror and the lower input beam; and f. means for converging the plurality of first and second output scans onto the fixed path such that the optical output beam from said scanner repetitively scans the fixed path thereby eliminating the effect of the facet to axis errors of the first and second mirrors and doubling the effective scan efficiency of the optical scanner.

Claim 3

The optical scanner of claim 1 wherein the first mirror comprises a first polygon mirror and wherein the second mirror comprises a second polygon mirror.

Claim 4

The optical scanner of claim 1 wherein said first redirecting means comprises a first prism and wherein said second redirecting means comprises a second prism.

Claim 5

The optical scanner of claim 1 wherein the upper input beam is parallel to the lower input beam.

Claim 6

The optical scanner of claim 1 wherein the upper input beam is positioned within a first plane and the lower input beam is positioned within a second plane and wherein the first and second planes are parallel.

Claim 7

The optical scanner of claim 5 wherein the upper and lower input beams are oriented perpendicular to the first axis of said scanner.

Claim 8

The optical scanner of claim 3 wherein said first and second prisms comprise 90° prisms.

Claim 9

The optical scanner of claim 7 wherein the first prism is positioned directly above the second prism and wherein the hypotenuse faces of the first and second prisms lie in the same plane.

Claim 10

The optical scanner of claim 8 wherein the hypotenuse faces of the first and second prisms are oriented parallel to the first axis of said scanner.

Claim 11

The optical scanner of claim 1 wherein the first and second polygon mirrors include an equal number of facets.

Claim 12

The optical scanner of claim 1 wherein said converging means includes a positive lens.

Claim 13

The optical scanner of claim 1 wherein said first and second polygon mirrors are rotated by a single motor having an output shaft coincident with the first axis of said scanner.

Claim 14

The optical scanner of claim 1 wherein said converting means comprises: a. segmented reflecting means aligned to receive the input light beam and including a plurality of circumferentially spaced apart mirror facets having a centrally located, vertically oriented axis of rotation and mirror facet to axis errors, said reflecting means including a gap between pairs of adjacent mirror facets; b. means for rotating said reflecting means to sequentially reflect the input beam to generate a pulsed beam and a pulsed, non-reflected output beam; c. means for redirecting the pulsed beam back onto said reflecting means to generate a redirected pulsed beam vertically displaced from the pulsed beam by a distance related to mirror facet to axis error and laterally offset from the pulsed beam by a distance related to the angle between the mirror facet and the input light beam, wherein the redirected pulsed beam is reflected from each of said mirror facets to generate a pulsed reflected output beam; d. means for reflecting the pulsed non-reflected output beam onto the facets of the first polygon mirror to supply the upper input beam; and e. means for reflecting the pulsed reflected output beam onto the facets of the second polygon mirror to supply the lower input beams.

Claim 15

An optical scanner for receiving an input beam and for generating an optical output beam which repetitively scans a fixed path comprising: a. means for converting the input beam into alternating first and second input beams lying within non-intersecting planes; b. a first polygonal mirror repetitively rotated through an angle about a first axis for receiving the first input beam and for repetitively generating a first scan; c. a second polygonal mirror repetitively rotated through an angle about the first axis for receiving the second input beam and for repetitively generating a second scan, said first and second mirrors having random facet to axis errors and a relative phase angle greater than zero; d. first means for redirecting the first scan back onto the first mirror to form a first redirected scan, said first redirecting means including a first reflecting surface lying within a first plane and a second reflecting surface lying within a second plane oriented perpendicular to the first plane, said first and second planes intersecting along a first line oriented perpendicular to the first axis and positioned between the first scan and the first redirected scan, wherein the first redirected scan is reflected from the first mirror to generate a plurality of first output scans which are directed through parallel, non-conincident paths, the first redirected scan being vertically displaced from the first scan by a distance related to the mirror facet to axis error and laterally offset from the first scan by a distance related to the relative angle between the mirror and the first beam and wherein the first and second planes are oriented such that a plane bisecting the included angle between the first and second planes is also oriented perpendicular to the first axis to generate linear output scans in response to the first input beam; e. second means for redirecting the second scan back onto the second mirror to form a second redirected scan, said second redirecting means including a third reflecting surface lying within a third plane and a fourth reflecting surface lying within a fourth plane oriented perpendicular to the third plane, said third and fourth planes intersecting along a second line oriented perpendicular to the first axis and positioned between the second scan and the second redirected scan, wherein the second redirected scan is reflected from the second mirror to generate a plurality of second output scans which are directed through parallel, non-coincident paths, the second redirected scan being vertically displaced from the second scan by a distance related to the mirror facet to axis error and laterally displaced from the second scan by a distance related to the relative angle between the mirror and the lower input beam and wherein the third and fourth planes are oriented such that a plane bisecting the included angle between the third and fourth planes is oriented perpendicular to the first axis to generate linear output scans in response to the second input beam; and f. means for converging the plurality of first and second output scans onto the fixed path such that the optical output beam from said scanner repetitively scans the fixed path thereby eleminating the effective of the facet to axis errors of the first and second mirrors and doubling the effective mirror scan efficiency.

Claim 16

An optical scanner for receiving an input beam and for generating an optical output beam which repetitively scans a fixed path comprising: a. means for converting the input beam into alternating first and second input beams lying within non-intersecting planes; b. a first polygonal mirror repetitively rotated through an angle about a first axis for receiving the first input beam and for repetitively generating a first scan; c. a second polygonal mirror repetitively rotated through an angle about the first axis for receiving the second input beam and for repetitively generating a second scan, said first and second mirrors having random facet to axis errors and a relative phase angle greater than zero; d. first means for redirecting the first scan back onto the first mirror to form a first redirected scan, said first redirecting means including a first reflecting surface lying within a first plane and a second reflecting surface lying within a second plane oriented perpendicular to the first plane, said first and second planes intersecting along a first line oriented perpendicular to the first axis and positioned between the first scan and the first redirected scan, wherein the first redirected scan is reflected from the first mirror to generate a plurality of first output scans which are directed through parallel, non-conincident paths, the first redirected scan being vertically displaced from the first scan by a distance related to the mirror facet to axis error and laterally offset from the first scan by a distance related to the relative angle between the mirror and the first beam and wherein the first and second planes are oriented such that a plane bisecting the included angle between the first and second planes is also oriented perpendicular to the first axis to generate linear output scans in response to the first input beam; e. second means for redirecting the second scan back onto the second mirror to form a second redirected scan, said second redirecting means including a third reflecting surface lying within a third plane and a fourth reflecting surface lying within a fourth plane oriented perpendicular to the third plane, said third and fourth planes intersecting along a second line oriented perpendicular to the first axis and positioned between the second scan and the second redirected scan, wherein the second redirected scan is reflected from the second mirror to generate a plurality of second output scans which are directed through parallel, non-coincident paths, the second redirected scan being vertically displaced from the second scan by a distance related to the mirror facet to axis error and laterally displaced from the second scan by a distance related to the relative angle between the mirror and the lower input beam and wherein the third and fourth planes are oriented such that a plane bisecting the included angle between the third and fourth planes is oriented perpendicular to the first axis to generate linear output scans in response to the second input beam; and f. means for converging the plurality of first and second output scans onto the fixed path such that the optical output beam from said scanner repetitively scans the fixed path thereby eleminating the effective of the facet to axis errors of the first and second mirrors and doubling the effective mirror scan efficiency.

Claim 17

The optical scanner of claim 14 wherein the upper and lower input beams comprise fixed alignment, constant position input beams.

Claim 18

The optical scanner of claim 14 wherein the first plane is parallel to the third plane.

Claim 19

The optical scanner of claim 16 wherein the second plane is parallel to the fourth plane.

Claim 20

The optical scanner of claim 17 wherein said first redirecting means comprises a first prism and wherein said second redirecting means comprises a second prism.

Claim 21

The optical scanner of claim 14 wherein said first redirecting means comprises a first prism and wherein said second redirecting means comprises a second prism.