Light emission unit

• US 6,479,942 B2
• Filed: 04/04/2001
• Issued: 11/12/2002
• Est. Priority Date: 04/05/2000
• Status: Expired due to Fees

• Current Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Inventors: Kimura, Tsutomu
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): VO, TUYET THI
• Application Number:
  US09/825,306
• Publication Number:
  US 20010028223A1
• Time in Patent Office: 587 Days
• Field of Search: 315/169.3, 315/169.4, 315/169.1, 396/322, 396/547, 362/800
• US Class Current: 315/169.3
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light emission device includes organic light emission element arrays for red, green and blue, each of which has a plurality of microscopic organic light emission elements arranged in line. Three-color recording light beams of one line emitted from said organic light emission element arrays are applied to an instant photo film through corresponding condenser lenses and graded-index type optical fiber. The condenser lenses are formed integrally with a surface of a transparent plate, on the other side of which the organic light emission element arrays for red, green and blue are stacked. In order to correct axial chromatic aberration, radius of curvature of each condenser lens is varied in accordance with the color of light beam emitted from corresponding organic light emission element.

Claims

1. A light emission unit comprising:

a plurality of light emission element arrays for emitting a plurality of linear light beams of different color from a light emitting surface, each of said light emission element arrays having a plurality of light emission elements arranged in line for emitting light beam of same color;

a transparent plate for protecting said light emitting surface of said light emission element arrays; and

a plurality of lens arrays arranged on said transparent plate such that each of said lens arrays corresponds to each of said light emission element arrays, respective said lens array including a plurality of condenser lenses, each of which is faced to each of said light emission elements;

wherein the plurality of lens arrays and the transparent plate are respective portions of a single piece of transparent material.

2. The light emission unit of claim 1, wherein each of the light emission elements is separated from a respective said condenser lens by a gap.

3. The light emission unit of claim 1, wherein the transparent plate comprises a plurality of convex portions on a side of the plate opposite the light emission element arrays, each of the convex portions corresponding to one of the light emission elements.

4. A light emission unit as defined in claim 1, wherein a plurality of said light emission element arrays include a light emission element array for red for emitting linear light beam of red, a light emission element array for green for emitting linear light beam of green, and a light emission element array for blue for emitting linear light beam of blue.

5. A light emission unit as defined in claim 4, wherein a radius of curvature of said condenser lens becomes smaller as wavelength of light beam of corresponding said light emission element becomes longer.

6. A light emission unit as defined in claim 5, wherein said light emission element arrays of red, green and blue are arranged in this order listed, and said condenser lenses for red and blue are located such that their optical axes are shifted from optical axes of corresponding light emission elements toward said condenser lens for green.

7. A light emission unit used for printer, said printer exposing an image to a photosensitive material, said light emission unit comprising:

a plurality of light emission element arrays for emitting a plurality of linear light beams of different color from a light emitting surface, each of said light emission element arrays having a plurality of light emission elements arranged in line for emitting light beam of same color;

a transparent plate for protecting said light emitting surface of said light emission element arrays; and

a plurality of lens arrays arranged on a first side of said transparent plate such that each of said lens arrays corresponds to each of said light emission element arrays, respective said lens array including a plurality of condenser lenses, each of which is faced to each of said light emission elements;

wherein the plurality of lens arrays and the transparent plate are respective portions of a single piece of transparent material.

8. The light emission unit of claim 7, wherein each of the light emission elements is separated from a respective said condenser lens by a gap.

9. The light emission unit of claim 7, wherein the transparent plate comprises a plurality of convex portions on a side of the plate opposite the light emission element arrays, each of the convex portions corresponding to one of the light emission elements.

10. A light emission unit as defined in claim 7, wherein said condenser lens is a convex lens provided on a side of said photosensitive material.

11. A light emission unit as defined in claim 10, further comprising:

a focusing lens array being disposed between said light emission element arrays and said photosensitive material, said light beams from said light emission element arrays are focused on said photosensitive material through said focusing lens array, said focusing lens array having a plurality of graded-index type optical fibers arranged in line.

12. A light emission unit as defined in claim 11, wherein said light emission element array includes:

a transparent positive electrode;

an organic compound layer stacked on said positive electrode, said organic compound layer including organic light emission elements for emitting said light beams;

a negative electrode stacked on said organic compound layer, said light beam being reflected by said negative electrode toward said positive electrode; and

wherein said positive electrode, said organic compound layer and said negative electrode are provided on a second surface of said transparent plate.

13. A light emission unit as defined in claim 12, wherein said organic compound layer includes:

an organic light emission element array for red for emitting linear light beam of red;

an organic light emission element array for green for emitting linear light beam of green; and

an organic light emission element array for blue for emitting linear light beam of blue.

14. A light emission unit as defined in claim 13, wherein a radius of curvature of said condenser lens becomes smaller as wavelength of light beam of corresponding said light emission element becomes longer, such that said red, green and blue light beams are focused on said photosensitive material.

15. A light emission unit as defined in claim 14, wherein said light emission element arrays of red, green and blue are arranged in this order listed, and said condenser lenses for red and blue are located such that their optical axes are shifted from optical axes of corresponding light emission elements toward said condenser lens for green.

16. A light emission unit as defined in claim 11, wherein said plural light emission element arrays includes:

a red LED element array for red for emitting linear light beam of red;

a green LED element array for green for emitting linear light beam of green; and

a blue LED element array for blue for emitting linear light beam of blue.

17. A light emission unit as defined in claim 16, wherein a radius of curvature of said condenser lens becomes smaller as wavelength of corresponding said light emission element becomes longer, such that said red, green and blue light beams are focused on said photosensitive material.

18. A light emission unit as defined in claim 17, wherein said light emission element arrays of red, green and blue are arranged in this order listed, and said condenser lenses for red and blue are located such that their optical axes are shifted from optical axes of corresponding light emission elements toward said condenser lens for green.