Laser printer using a fly's eye integrator

• US 5,923,475 A
• Filed: 11/27/1996
• Issued: 07/13/1999
• Est. Priority Date: 11/27/1996
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Kurtz, Andrew F., Kessler, David
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): LETENDRE, SUZANNE M
• Application Number:
  US08/757,889
• Time in Patent Office: 958 Days
• Field of Search: 359/619, 359/621, 359/626
• US Class Current: 359/619
• CPC Class Codes: B41J 2/451 Special optical means therefor, e.g. lenses, mirrors, focusing means
• CPC Class Codes: B41J 2/465 using masks, e.g. light-switching masks
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/0966 Cylindrical lenses cylindrical lenses per se G02B3/06

Abstract

A laser printer (10) is comprised of a laser diode array (11), a cross array illumination optics (21), a laser lenslet array (24), a spatial light modulator (40), and a fly'"'"'s eye integrator (23) which illuminates the spatial light modulator with flooded uniform light.

In another embodiment the angular spectrum of the light incident to the spatial light modulator is tailored to enhance the quality of modulation. The spatial light modulator (40), is illuminated uniformly by laser diode emitters (12) comprising laser diode array (11), and the spatial light modulator (40) break up the light into image elements, which are subsequently imaged to a media plane (60), to form a desired pattern of spots.

Claims

1. A laser printer for printing onto a light sensitive media comprising:

a laser array comprised of a plurality of laser diode emitters each of which emits a beam of light;

cross array illumination optics for reducing a divergence of light beams from the plurality of laser diode emitters;

a laser lenslet array having lenslet elements, each lenslet element of the laser lenslet array receiving a light beam from each laser diode emitter;

at least one fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of a spatial light modulator comprised of a plurality of modulator sites; and

a print lens for imaging the spatial light modulator onto the light sensitive media.

2. A laser printer as in claim 1 wherein said fly'"'"'s eye integrator is comprised of a first uniformizer lenslet array and a second uniformizer lenslet array.

3. A laser printer as in claim 2 wherein a field lens is located between said fly'"'"'s eye integrator and said laser lenslet array.

4. A laser printer as in claim 2 wherein a field lens is located between said fly'"'"'s eye integrator and said spatial light modulator.

5. A laser printer as in claim 1 wherein said fly'"'"'s eye integrator is divided into segments, each segment having an array of lens elements patterned on a first surface and a corresponding array of lens elements patterned on a second surface, and each segment corresponds to a laser diode emitter and a lenslet element.

6. A laser printer as in claim 5 wherein said first surface has a first number of facets and said second surface has a second number of facets and said first number and said second number are equal.

7. A laser printer as in claim 5 wherein said laser lenslet array provides Koehler illumination to said fly'"'"'s eye integrator.

8. A laser printer as in claim 5 wherein a first group of segments has an even number of lens elements on said first and second surfaces and a second group of segments has an odd number of lens elements on said first and second surfaces.

9. A laser printer as in claim 8 wherein said group one segments alternate with group two segments.

10. An illumination system comprising:

a laser array comprised of a plurality of laser diode emitters each of which emits a beam of light;

cross array illumination optics for reducing a divergence of light beams from the plurality of laser diode emitters;

a laser lenslet array having lenslet elements, each lenslet element of the laser lenslet array receiving a light beam from each laser diode emitter; and

at least one fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of a plane.

11. An illumination system as in claim 10 wherein a spatial light modulator is located at said plane.

12. A printer for printing onto a light sensitive media comprising:

a LED array comprised of a plurality of LED emitters each of which emits a beam of light;

a lenslet array having lenslet elements, each lenslet element of the lenslet array receiving a light beam from each LED emitter;

a fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of a spatial light modulator comprised of a plurality of modulator sites; and

a print lens for imaging the spatial light modulator onto the light sensitive media.

13. A laser printer for printing onto a light sensitive media comprising:

a laser array comprised of a plurality of laser diode emitters each of which emits a beam of light;

a laser lenslet array having lenslet elements, each lenslet element of the laser lenslet array receiving a light beam from each laser diode emitter;

a fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of a spatial light modulator comprised of a plurality of modulator sites; and

a print lens for imaging the spatial light modulator onto the light sensitive media.

14. A laser printer for printing onto a light sensitive media comprising:

a laser array comprised of a plurality of laser diode emitters each of which emits a beam of light;

cross array illumination optics for reducing a divergence of light beams from the plurality of lasers diode emitters;

a laser lenslet array having lenslet elements, each lenslet element of the laser lenslet array receiving a light beam from each laser diode emitter;

a fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of a spatial light modulator comprised of a plurality of modulator sites wherein said fly'"'"'s eye integrator is divided into segments, each segment having an array of lens elements patterned on a first surface and a corresponding array of lens elements patterned on a second surface; and

a print lens for imaging the spatial light modulator onto the light sensitive media.

15. A laser printer as in claim 14 wherein a field lens is located between said fly'"'"'s eye integrator and said spatial light modulator.

16. A laser printer for printing onto a light sensitive media comprising:

a multitude of laser diode arrays comprised of a plurality of laser diode emitters each of which emits a beam of light;

cross array illumination optics for reducing a divergence of light beams from the plurality of laser diode emitters;

a laser lenslet array having lenslet elements, each lenslet element of the laser lenslet array receiving a light beam from each laser diode emitter;

a fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of at least one spatial light modulator comprised of a plurality of modulator sites; and

a print lens for imaging the spatial light modulator onto the light sensitive media.

17. A laser printer for printing onto a light sensitive media comprising:

a first laser diode array comprised of a plurality of laser diode emitters each of which emits a beam of light;

a second laser diode array comprised of a plurality of laser diode emitters each of which emits a beam of light;

cross array illumination optics for reducing a divergence of light beams from the plurality of laser diode emitters;

a laser lenslet array having lenslet elements, each lenslet element of the laser lenslet array receiving a light beam from one laser diode emitter in said first laser diode array and one laser diode emitter in said second laser diode array;

a fly'"'"'s eye integrator for providing spatially and angularly homogenized uniform flood illumination of a first and second spatial light modulator, each comprised of a plurality of modulator sites, wherein said first spatial light modulator is illuminated primarily by said first laser diode array and said second spatial light modulator is illuminated primarily by said second laser diode array; and

a print lens for imaging the spatial light modulators onto the light sensitive media.