Exposure apparatus for irradiating a sensitized substrate

• US 20030206337A1
• Filed: 05/06/2002
• Published: 11/06/2003
• Est. Priority Date: 05/06/2002
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Kessler, David, Liang, Rongguang
• Application Number:
  US10/139,489
• Publication Number:
  US 20030206337A1
• Time in Patent Office: Days
• US Class Current: 359/352
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation

Abstract

An exposure apparatus (10) for applying high-intensity, uniform polarized UV irradiation to a sensitized substrate such as an LCD alignment layer. A telecentric projection system (20) projects a uniformized light towards a surface (28) for irradiation. One or more individual light sources (12) can be combined to provide the intensity needed over the area of the surface (28). An integrator (40) with combining structures (42) allows combination of light from multiple light sources (12). A polarizer (18) is provided at one of an alternate number of locations in the exposure illumination path.

Claims

1. An apparatus for uniform irradiation of a substrate, comprising:

(a) a light source for providing source radiation;

(b) a uniformizing component for homogenizing said source radiation to provide a uniform exposure beam having uniform energy across the field;

(c) a polarizer for conditioning said uniform exposure beam to provide a polarized uniform exposure beam; and

(d) a telecentric projection system for projecting said polarized uniform exposure beam onto the substrate.

2. An apparatus for irradiating a substrate according to claim 1 wherein said light source provides UV light.

3. An apparatus for irradiating a substrate according to claim 1 wherein said light source comprises:

(a) at least two lamps; and

(b) an optical combiner for combining light from said at least two lamps to provide said source radiation.

4. An apparatus for irradiating a substrate according to claim 3 wherein an integrating bar acts as said optical combiner.

5. An apparatus for irradiating a substrate according to claim 1 wherein said light source further comprises a heat sink.

6. An apparatus for irradiating a substrate according to claim 1 wherein said uniformizing component comprises an integrating bar.

7. An apparatus for irradiating a substrate according to claim 1 wherein said uniformizing component comprises a lenslet array.

8. An apparatus for irradiating a substrate according to claim 1 wherein said polarizer comprises a wire-grid polarizer.

9. An apparatus for irradiating a substrate according to claim 1 wherein said polarizer can be rotated to change the angle of polarization on said substrate.

10. An apparatus for irradiating a substrate according to claim 1 wherein said polarizer comprises a Brewster plate polarizer.

11. An apparatus for irradiating a substrate according to claim 3 wherein said optical combiner is a dichroic combiner.

12. An apparatus for irradiating a substrate according to claim 1 further comprising a mirror for directing said polarized uniform exposure beam toward said substrate.

13. An apparatus for irradiating a substrate according to claim 12 wherein said mirror is a substantially spherical segment.

14. An apparatus for irradiating a substrate according to claim 12 wherein said mirror allows a tilt adjustment for changing the incident angle of said polarized uniform exposure beam.

15. An apparatus for irradiating a substrate according to claim 3 wherein the number of said at least two lamps is determined by the area of the substrate to be irradiated at one time.

16. An apparatus for irradiating a substrate according to claim 1 wherein said substrate is an alignment material for liquid-crystal device fabrication.

17. An apparatus for irradiating a substrate according to claim 1 wherein said substrate is moved over an exposure area.

18. An apparatus for irradiating a substrate according to claim 1 wherein said polarizer comprises a polarizing beamsplitter for transmitting light of a first polarization and reflecting light of a second polarization.

19. An apparatus for irradiating a substrate according to claim 18 wherein said polarizer further comprises a waveplate for rotating the polarization state of said first polarization.

20. An apparatus for irradiating a substrate according to claim 18 wherein said polarizer further comprises a waveplate for rotating the polarization state of said second polarization.

21. An apparatus for uniform irradiation of a substrate comprising:

(a) a light source for providing source radiation;

(b) a uniformizing component for homogenizing said source radiation to provide a uniform exposure beam;

(c) a telecentric projection system for projecting said uniform exposure beam toward said substrate; and

(d) a polarizer for conditioning said uniform exposure beam to provide a polarized uniform exposure beam.

22. An apparatus for uniform irradiation of a substrate according to claim 21 wherein said polarizer is disposed near said substrate.

23. An apparatus for uniform irradiation of a substrate comprising:

(a) a light source for providing source radiation;

(b) a uniformizing component for homogenizing said source radiation to provide a uniform exposure beam having uniform energy; and

(c) a telecentric projection system comprising a polarizer for conditioning said uniform exposure beam to provide a polarized uniform exposure beam, said telecentric projection system projecting said polarized uniform exposure beam onto said substrate.

24. An apparatus for uniform irradiation of a substrate according to claim 23 wherein said uniformizing component provides homogenized light from a plurality of light sources, said uniformizing component comprising:

(a) for each light source, a light channel for directing light into said uniformizing component; and

(b) at least one prism structure for turning light into said uniformizing component.

25. An apparatus for uniform irradiation of a substrate comprising:

(a) means for providing source radiation;

(b) means for homogenizing said source radiation to provide spatially uniform energy;

(c) means for polarizing said source radiation; and

(d) means for telecentric projection of said source radiation onto said substrate.

26. A method for irradiating a sensitized surface comprising:

(a) providing a source radiation beam;

(b) uniformizing said source radiation beam to provide a uniform exposure beam;

(c) polarizing said uniform exposure beam to provide a polarized uniform exposure beam; and

(d) projecting said uniform exposure beam as a telecentric exposure beam.

27. A method for irradiating a sensitized surface according to claim 26 wherein the step of providing a source radiation beam comprises the step of combining light from at least two lamps.

28. A method for irradiating a sensitized surface according to claim 26 wherein the step of uniformizing said source radiation beam comprises the step of directing said source radiation beam through an integrating bar.

29. A method for irradiating a sensitized surface according to claim 26 wherein the step of polarizing comprises the step of directing said uniform exposure beam through a wire grid polarizer.

30. A method for irradiating a sensitized surface according to claim 26 wherein the step of projecting further comprises the step of reflecting said telecentric exposure beam from a reflective surface.

31. A method for irradiating a sensitized surface according to claim 30 wherein said reflective surface is curved.

32. A method for irradiating a sensitized surface according to claim 26 wherein said source radiation beam provides ultraviolet light.

33. A method for irradiating a sensitized surface comprising:

(a) providing a source radiation beam;

(b) uniformizing said source radiation beam to provide a uniform exposure beam;

(c) polarizing said uniform exposure beam with a polarizer rotated to a first position to provide a polarized uniform exposure beam having a first polarization;

(d) projecting said uniform exposure beam having said first polarization as a telecentric exposure beam;

(e) polarizing said uniform exposure beam with a polarizer rotated to a second position to provide a polarized uniform exposure beam having a second polarization; and

(f) projecting said uniform exposure beam having said second polarization as a telecentric exposure beam.