Laser scanning utilizing facet tracking and acousto pulse imaging techniques

Claim 2

An improved flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of radiant energy; means for generating a signal representing the start or end of a scan; a Bragg diffraction light-sound interaction medium including a transducer coupled to an acoustic wave transmitting medium characterized by a predetermined acoustic wave propagation velocity, said medium both modulating and deflecting said beam in accordance with the information content of a drive signal applied thereto, scanning means having at least one reflective surface positioned in the optical path of said modulated and deflected beam for scanning said beam across said scanned medium by rotating said reflective surface a desired angle to impart the information content of said beam to said scanned medium; means responsive to the start or end of a scan signal and said electrical signal for providing said drive signal, said drive signal causing said beam to track said reflective surface during the rotation and translation of said reflective surface during said scan, said drive signal being coupled to said transducer for also propagating intensity-modulated acoustic waves in said medium at a predetermined velocity, said beam of radiant energy being projected through said medium in a direction transverse to said acoustic waves to produce in said medium a moving image of information corresponding to said electrical signal, said image moving at said predetermined velocity, and optical means interposed in the path of said intensity modulated beam and having magnification M associated therewith, for minimizing image blur on a recording medium said moving image being projected onto said scanned medium with said beam in a manner such that the velocity of said moving image is substantially equal to and in an opposite direction as the velocity of said scanning beam.

Claim 3

The system as defined in claim 1 wherein said scanned medium comprises a rotating xerographic member.

Claim 4

The system as defined in claim 2 wherein the magnification M is selected such that M is substantially equal to V 3 /V 1 wherein M is the system magnification between the interaction medium and said scanned medium, V 3 is the velocity of the beam spot scanning across the surface of said scanned medium, and V 1 is said predetermined velocity.

Claim 5

The system as defined in claim 1 wherein said beam providing means comprises a laser.

Claim 6

The system of claim 1 wherein said drive signal means includes: first means for providing an output signal of constant amplitude and a frequency dependent upon a voltage applied to its input; means responsive to the start or end of scan signal for generating said input voltage, said input voltage being proportional to the distance travelled by said reflective surface during a scan; and means for processing said electrical signal and said output signal to provide said drive signal.

Claim 7

The system of claim 1 wherein the scanning means includes a multifaceted polygon having reflective facets for reflecting the radiant energy incident to it onto said medium and means for rotating said polygon such that the reflected light is scanned in successive traces across said medium.

Claim 8

The system as defined in claim 1 wherein the modulation and deflection of said beam is accomplished simultaneously.

Claim 9

The system of claim 1 wherein said beam tracks a discrete area of said reflective surface.

Claim 10

The system of claim 5 wherein said voltage input comprises a linear ramp whose duration corresponds substantially to the time required to scan one trace.

Claim 11

The system as defined in claim 1 wherein the magnification M is the magnification in a direction parallel to the direction of scan.

Claim 12

An improved flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of radiant energy; means for generating a signal representing the start or end of scan; a Bragg diffraction light-sound interaction medium including a transducer coupled to an acoustic wave transmitting medium characterized by a predetermined acoustic wave propagation velocity, said medium modulating said beam in accordance with the information content of said electrical signal applied thereto, deflecting means positioned to receive said modulated beam and for deflecting said beam in accordance with a first electrical signal applied thereto, scanning means having at least one reflective surface positioned in the optical path of said modulated and deflected beam for scanning said beam across said medium by rotating said scanned reflective surface a desired angle to impart the information content of said beam to said scanned medium; means responsive to the start or end of scan signal for providing said first electrical signal, said first electrical signal causing said beam to track said reflective surface during the rotation and translation of said reflective surface during said scan, said electrical signal being coupled to said transducer for propagating intensity-modulated acoustic waves in said medium at a predetermined velocity, said beam being projected through said medium in a direction transverse to said acoustic waves to produce in said medium a moving image of information corresponding to said electrical signal, said image moving at said predetermined velocity, and optical means interposed in the path between said intensity modulated and deflected beam and having a magnification M associated therewith, for minimizing image blur on a recording medium said moving image being projected onto said scanned medium with said beam in a manner such that the velocity of said moving image is substantially equal to and in an opposite direction as the velocity of said scanning beam.

Claim 13

An improved flying spot scanning system for recording information from an electrical signal onto a scanned medium comprising: means for providing a beam of radiant energy; means for generating a signal representing the start or end of scan; a Bragg diffraction light-sound interaction medium including a transducer coupled to an acoustic wave transmitting medium characterized by a predetermined acoustic wave propagation velocity, said medium modulating said beam in accordance with the information content of said electrical signal applied thereto, deflecting means positioned to receive said modulated beam and for deflecting said beam in accordance with a first electrical signal applied thereto, scanning means having at least one reflective surface positioned in the optical path of said modulated and deflected beam for scanning said beam across said medium by rotating said scanned reflective surface a desired angle to impart the information content of said beam to said scanned medium; means responsive to the start or end of scan signal for providing said first electrical signal, said first electrical signal causing said beam to track said reflective surface during the rotation and translation of said reflective surface during said scan, said electrical signal being coupled to said transducer for propagating intensity-modulated acoustic waves in said medium at a predetermined velocity, said beam being projected through said medium in a direction transverse to said acoustic waves to produce in said medium a moving image of information corresponding to said electrical signal, said image moving at said predetermined velocity, and optical means interposed in the path between said intensity modulated and deflected beam and having a magnification M associated therewith, for minimizing image blur on a recording medium said moving image being projected onto said scanned medium with said beam in a manner such that the velocity of said moving image is substantially equal to and in an opposite direction as the velocity of said scanning beam.

Claim 14

The system as defined in claim 11 wherein said scanned medium comprises a rotating xerographic member.

Claim 15

The system as defined in claim 12 wherein the magnification M is selected such that M is substantially equal to V 3 /V 1 wherein M is the system magnification between the interaction medium and said scanned medium, V 3 is the velocity of the beam spot scanning across the surface of said scanned medium and V 1 is said predetermined velocity.

Claim 16

The system as defined in claim 11 wherein said beam providing means comprises a laser.

Claim 17

The system of claim 11 wherein said drive signal means for providing said first electrical signal includes: first means for providing an output signal of constant amplitude and a frequency dependent upon a voltage applied to its input; and means responsive to the start or end of scan signal for generating said input voltage, said input voltage being proportional to the distance travelled by said reflective surface during a scan.

Claim 18

The system of claim 11 wherein the scanning means includes a multifaceted polygon having reflective facets for reflecting the radiant energy incident to it onto said medium and means for rotating said polygon such that the reflected light is scanned in successive traces across said medium.

Claim 19

The system as defined in claim 11 wherein said beam tracks a discrete area of said reflective surface.

Claim 20

The system of claim 11 wherein said first electrical signal comprises a linear ramp whose duration corresponds substantially to the time required to scan one trace.

Claim 21

The system as defined in claim 10 wherein the magnification M is the magnification in a direction parallel to the direction of scan.