Optical system having extended angular scan range
View Patent ↗System and method for scanning light across a light-receiving surface. A system for scanning light across a light-receiving surface to project a scanned line on the light-receiving surface has a light beam generator for generating a plurality of light beams. A scanning mechanism simultaneously scans each light beam of the plurality of light beams across the light-receiving surface to project a different portion of the scanned line on the light-receiving surface. The scanning system can be utilized in a compact laser printer capable of printing at a high rate, and in other scanning applications.
1. A method for scanning light across a surface of a rotating drum in a printer to project a scanned line on the surface, comprising:
generating at least three light beams;
relaying each of the at least three generated light beams to impinge on a Micro-Electro-Mechanical System scanning mirror at different propagation angles; and
simultaneously scanning each light beam of the at least three light beams across the surface of the drum in alignment with one another with the Micro-Electro-Mechanical System scanning mirror to project a different portion of the scanned line on the surface.
2. The method according to claim 1 , and further including correcting misalignment between adjacent light beams during a scanning operation.
3. The method according claim 1 , wherein the at least three light beams comprises three light beams.
4. A printer, comprising:
a drum; and
a system for scanning light across a surface of the drum to project a scanned line on the surface of the drum, the system comprising:
a light beam generator for generating at least three light beams;
a Micro-Electro-Mechanical System scanning mirror for simultaneously scanning each light beam of the at least three light beams across a surface of the drum in alignment with one another to project a different portion of the scanned line on the surface of the drum; and
relay optics for relaying each of the at least three light beams from the light beam generator to impinge on the Micro-Electro-Mechanical System scanning mirror at a different propagation angle.
5. The printer according to claim 4 , wherein the optics for relaying each of the at least three light beams to impinge on the Micro-Electro-Mechanical System scanning mirror at a different propagation angle includes a plurality of stationary mirrors.
6. The printer according to claim 4 , wherein the optics for relaying each of the at least three light beams to impinge on the Micro-Electro-Mechanical System scanning mirror at a different propagation angle includes a diffractive element.
7. The printer according to claim 4 , and further including light focusing structure for focusing the at least three light beams on the light-receiving surface, wherein the light focusing structure includes at least one fΘ lens.
8. The printer according to claim 4 , and further including a stitching mechanism for correcting misalignment between adjacent light beams during a scanning operation, wherein the stitching mechanism comprises a mechanism for causing light beams to overlap in stitching regions between adjacent light beams.
9. The printer according to claim 8 , wherein the stitching mechanism further comprises a mechanism for adjusting a combined power of adjacent light beams in stitching regions.
10. The printer according to claim 9 , wherein the mechanism for adjusting a combined power of adjacent light beams in stitching regions comprises one of an optical mechanism and an electronic mechanism.
11. The printer according to claim 4 , wherein the at least three light beams comprises three light beams, each light beam providing approximately one-third of the scanned line.
12. The printer according to claim 11 , wherein the three light beams comprise a first light beam on an optical axis of the system for scanning light across a surface of the drum to project a scanned line on the surface of the drum, and second and third light beams on opposite sides of the first light beam.
13. The printer according to claim 4 , wherein the Micro-Electro-Mechanical System scanning mirror prints about 32,000 lines per minute on the drum surface.
14. The printer according to claim 4 , wherein the light beam generator comprises at least three lasers.
15. The printer according to claim 14 , wherein the at least three lasers comprises at least three Vertical Cavity Surface Emitting Lasers.