Dual beam laser display device employing polygonal mirror

Claim 2

In a display system wherein a beam of light is modulated in accordance with an information signal and steered to scan a display screen, the combination which comprises: a. modulator means positioned in the path of the beam of light, said modulator means resolving said beam intO first and second component beams and modulating the intensity thereof in accordance with the information signal; b. beam scanning means containing a polygonal mirror having a plurality of reflecting faces, said mirror being rotatable about an axis of rotation, and c. means interposed between said modulator and beam scanning means for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axes of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during traversal of the second beam, the rotation of said polygonal mirror resulting in the alternate scanning of the screen by said first and second component beams.

Claim 3

The combination of claim 1 further comprising means for applying first and second modulating signals to said modulator means, said first signal alternating between first and second voltage levels and said second signal containing the information to be displayed whereby said first and second components are alternately modulated with positive display information.

Claim 4

The combination of claim 2 wherein said beam scanning means contains means for rotating said polygonal mirror in synchronism with the first modulating signal applied to said modulator means whereby the transition between levels of said first modulating signal occurs prior to the generation of the next line scan.

Claim 5

The combination of claim 1 wherein each face of the polygonal mirror has a width which is approximately twice the diameter of a component beam.

Claim 6

The combination of claim 1 wherein said polygonal mirror has n individual faces and the means for directing said first and second components to adjacent positions on the mirror provides an angle phi between said components which is equal to 360/n.

Claim 7

The combination of claim 1 wherein each face of the polygonal mirror has a width which is not less than twice the diameter of a component beam whereby the retrace interval between successive line scans is minimized.

Claim 8

The combination of claim 1 further comprising a vertical beam scanner positioned to receive the line scan generated by said beam scanning means, said vertical scanner being oriented to steer an incident beam in a direction orthogonal to the line scan and thereby provide a raster.

Claim 9

A display system for providing a television image on a display screen which comprises: a. means for providing a beam of light; b. an intensity modulator positioned in the path of said beam of light, said modulator resolving said beam into first and second intensity-modulated component beams; c. means for applying first and second modulating signals to said modulator, said first signal having a square waveform, said second signal containing the video information to be displayed, said first and second signals providing alternate modulation of said first and second components with positive video information, d. a dual beam scanner containing a rotating polygonal mirror having n reflecting faces, each of said faces having a width which is approximately twice the diameter of a component beam; e. means interposed between said intersecting modulator and dual beam scanner for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axes of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during traversal of the second beam, the rotation of said mirror reSulting in the alternate scanning of a line by said first and second component beams, f. a single beam scanner positioned to receive the line scan generated by said dual beam scanner, said single beam scanner providing deflection in a direction orthogonal to the line scan and thereby provide a raster on the display screen.

Claim 10

A display system for providing a television image on a display screen which comprises: a. means for providing a beam of light; b. an intensity modulator positioned in the path of said beam of light, said modulator resolving said beam into first and second intensity-modulated component beams; c. means for applying first and second modulating signals to said modulator, said first signal having a square waveform, said second signal containing the video information to be displayed, said first and second signals providing alternate modulation of said first and second components with positive video information, d. a dual beam scanner containing a rotating polygonal mirror having n reflecting faces, each of said faces having a width which is approximately twice the diameter of a component beam; e. means interposed between said intersecting modulator and dual beam scanner for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axes of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during traversal of the second beam, the rotation of said mirror reSulting in the alternate scanning of a line by said first and second component beams, f. a single beam scanner positioned to receive the line scan generated by said dual beam scanner, said single beam scanner providing deflection in a direction orthogonal to the line scan and thereby provide a raster on the display screen.

Claim 11

The display of claim 8 wherein said means for directing said first and second components to adjacent positions on the mirror provides an angle phi therebetween which is equal to 360/n.

Claim 12

The combination of claim 8 further comprising means for applying first and second modulating signals to said modulator, said first signal alternating between first and second voltage levels and said second signal containing the information to be displayed whereby said first and second components are alternately modulated with positive display information.

Claim 13

The display of claim 8 wherein said intensity modulator is an electro-optic light modulator and further comprising a beam splitter positioned at the output of said modulator for spatially separating the first and second component beams.

Claim 14

The display of claim 8 further comprising: a. photodetecting means interposed between the single beam scanner and the display screen for providing output signals in accordance with the generation of the raster, and b. sync detection means coupled to said photodetecting means for comparing the signals from said photodetecting means with the received sync signals and generating corrective signals accordingly, said corrective signals being supplied to the beam scanners.

Claim 15

A display system for providing a color television image on a display screen which comprises: a. means for providing first, second and third beams of light of different wavelengths; b. first, second and third intensity modulators, each of said modulators being positioned in the path of the corresponding beam of light, each modulator resolving its beam into first and second intensity-modulated component beams; c. means for combining the first component beams from said modulators to form a first composite beam and for combining the second component beam from said modulators to form a second composite beam; d. means for applying first and second modulating signals to each of said modulators, said first signal having a square waveform, said second signal containing the color video information corresponding to a particular modulator, said first and second signals providing alternate modulation of said first and second components with positive video information; e. a dual beam scanner containing a rotating polygonal mirror having n reflecting faces, each of said faces having a width which is approximately twice the diameter of the composite; f. means interposed between said intensity modulators and dual beam scanner for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axis of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during the traversal of the second beam, the rotation of said mirror resulting in the alternate scanning of a line by said first and second component beams; and g. a single beam scanner positioned to receive the line scan generated by said dual beam scanner, said single beam scanner providing deflection in a direction orthogonal to the line scan and thereby providing a raster on the display screen.

Claim 16

A display system for providing a color television image on a display screen which comprises: a. means for providing first, second and third beams of light of different wavelengths; b. first, second and third intensity modulators, each of said modulators being positioned in the path of the corresponding beam of light, each modulator resolving its beam into first and second intensity-modulated component beams; c. means for combining the first component beams from said modulators to form a first composite beam and for combining the second component beam from said modulators to form a second composite beam; d. means for applying first and second modulating signals to each of said modulators, said first signal having a square waveform, said second signal containing the color video information corresponding to a particular modulator, said first and second signals providing alternate modulation of said first and second components with positive video information; e. a dual beam scanner containing a rotating polygonal mirror having n reflecting faces, each of said faces having a width which is approximately twice the diameter of the composite; f. means interposed between said intensity modulators and dual beam scanner for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axis of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during the traversal of the second beam, the rotation of said mirror resulting in the alternate scanning of a line by said first and second component beams; and g. a single beam scanner positioned to receive the line scan generated by said dual beam scanner, said single beam scanner providing deflection in a direction orthogonal to the line scan and thereby providing a raster on the display screen.

Claim 17

The combination of claim 1 wherein the plane formed by the axes of said first and second component beams is perpendicular to the axis of rotation of said polygonal mirror.

Claim 18

A display system for providing a color television image on a display screEn which comprises: a. means for providing first, second and third beams of light of different wavelengths; b. first, second and third intensity modulators, each of said modulators being positioned in the path of the corresponding beam of light, each modulator resolving its beam into first and second intensity-modulated component beams; c. means for combining the first component beams from said modulators to form a first composite beam and for combining the second component beam from said modulators to form a second composite beam; d. means for applying first and second modulating signals to each of said modulators, said first signal having a square waveform, said second signal containing the color video information corresponding to a particular modulator, said first and second signals providing alternate modulation of said first and second components with positive video information; e. a dual beam scanner containing a rotating polygonal mirror having n reflecting faces, each of said faces having a width which is approximately twice the diameter of the composite; f. means interposed between said intensity modulators and dual beam scanner for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axis of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during the traversal of the second beam, the rotation of said mirror resulting in the alternate scanning of a line by said first and second component beams; and g. a single beam scanner positioned to receive the line scan generated by said dual beam scanner, said single beam scanner providing deflection in a direction orthogonal to the line scan and thereby providing a raster on the display screen.

Claim 19

A display system for providing a color television image on a display screEn which comprises: a. means for providing first, second and third beams of light of different wavelengths; b. first, second and third intensity modulators, each of said modulators being positioned in the path of the corresponding beam of light, each modulator resolving its beam into first and second intensity-modulated component beams; c. means for combining the first component beams from said modulators to form a first composite beam and for combining the second component beam from said modulators to form a second composite beam; d. means for applying first and second modulating signals to each of said modulators, said first signal having a square waveform, said second signal containing the color video information corresponding to a particular modulator, said first and second signals providing alternate modulation of said first and second components with positive video information; e. a dual beam scanner containing a rotating polygonal mirror having n reflecting faces, each of said faces having a width which is approximately twice the diameter of the composite; f. means interposed between said intensity modulators and dual beam scanner for directing said first and second component beams to adjacent positions on said rotating polygonal mirror and for making the axis of said beams coplanar with an angle phi therebetween, the orientation of said beams with respect to said polygonal mirror being such that said first and second component beams are alternately traversed by a boundary between adjacent reflecting faces, the first of said component beams being fully incident on a reflecting face during the traversal of the second beam, the rotation of said mirror resulting in the alternate scanning of a line by said first and second component beams; and g. a single beam scanner positioned to receive the line scan generated by said dual beam scanner, said single beam scanner providing deflection in a direction orthogonal to the line scan and thereby providing a raster on the display screen.

Claim 20

The display of claim 15 wherein said means for directing said first and second composite beams to adjacent positions on the mirror provides an angle phi therebetween which is equal to 360/n.