Method and apparatus for printing to a photosensitive media using multiple spatial light modulators

• US 6,407,766 B1
• Filed: 07/18/2000
• Issued: 06/18/2002
• Est. Priority Date: 07/18/2000
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Kessler, David, Ramanujan, Sujatha
• Primary Examiner(s): PHAM, HAI CHI
• Application Number:
  US09/618,661
• Time in Patent Office: 700 Days
• Field of Search: 347/239, 347/241, 347/255, 347/256, 347/237, 347/247, 353/20, 353/122, 349/5, 349/9, 359/494, 430/321, 355/67
• US Class Current: 347/239
• CPC Class Codes: B41J 2/465 using masks, e.g. light-switching masks
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G06K 15/1271 by light beam splitting
• CPC Class Codes: H04N 1/50 Picture reproducers for halftone screening H04N1/52

Abstract

A method of printing (10) to a photosensitive media contains the step of imaging light from a light source through an optics assembly to a polarization beamsplitter (80). The polarization beamsplitter (80) produces a first polarized state and a second polarized state. The first polarized state is directed to a first filter to a first spatial light modulator. The first spatial light modulator is addressed with a first color signal to modulate the first polarized beam which is reflected back through the polarization beamsplitter (80). A second polarized light is passed through a second filter to a second spatial light modulator. A second color signal causes said second spatial light modulator to reflect a second modulated light beam through the polarization beamsplitter (80). The first and second modulated light beam are focused through print lens (110) onto a photosensitive media.

Claims

1. A method of printing two-dimensional swaths of area onto a photosensitive media comprising the steps of:

imaging light from a light source through an optics assembly;

passing said light from said optics assembly through a polarization beamsplitter element to produce a first polarization state of said light and a second polarization state of said light;

directing said first polarized light to a first color filter;

passing said first polarized light from said first color filter to a first spatial light modulator to create an essentially telecentric illumination at said first spatial light modulator;

addressing said first spatial light modulator with a first color signal to create a first modulated light beam;

imaging said first modulated light beam through a print lens assembly on said photosensitive media;

directing said second polarized light to a second color filter;

passing said second polarized light from said second color filter to a second spatial light modulator to create an essentially telecentric illumination at said second spatial light modulator;

addressing said second spatial light modulator with a second color signal to create a second modulated light beam;

imaging said second modulated light beam through the print lens assembly on said photosensitive media;

addressing said second spatial light modulator with a third color signal to create a third modulated light beam;

imaging said third modulated light beam through the print lens assembly on said photosensitive media; and

wherein said second signal and said third color signal are processed simultaneously with said first color signal.

2. A method according to claim 1 wherein said first color signal is red.

3. A method according to claim 1 wherein said second color signal is green and said third color signal is blue.

4. A method according to claim 1 wherein said first color filter is part of said first spatial light modulator.

5. A method according to claim 1 wherein said second color filter is part of said second spatial light modulator.

6. A method according to claim 1 wherein said first color filter is integral with said beamsplitter.

7. A method according to claim 1 wherein said second color filter is integral with said beamsplitter.

8. A method according to claim 1 wherein said first color filter is switchable between multiple wavelengths.

9. A method according to claim 1 wherein said second color filter is switchable between multiple wavelengths.

10. A method according to claim 1 wherein at least one of said spatial light modulators is moved to spatially dither at least one of said modulated light beams.

11. A method according to claim 1 wherein said first spatial light modulator and said second spatial light modulator are moved in synchronization to dither said first modulated light beam and said second modulated light beam.

12. A method according to claim 1 wherein said light source is selected from a group comprised of LEDs, halogen light sources, or lasers.

13. A method according to claim 1 wherein said first color filter is a red filter.

14. A method according to claim 1 wherein said second color filter is a switchable blue and green filter.

15. A method according to claim 1 wherein said second color filter is a color filter wheel.

16. A method according to claim 1 wherein said light source produces a first, second, and third color simultaneously.

17. A method according to claim 1 wherein said light source produces a first color continuously and a second and third color sequentially.

18. A method according to claim 1 wherein said second filter is a multiple wavelength filter.