Light modulation element, exposure unit, and flat-panel display unit

• US 6,642,913 B1
• Filed: 01/19/2000
• Issued: 11/04/2003
• Est. Priority Date: 01/20/1999
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kimura, Koichi, Sawano, Mitsuru
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Dharia, Prabodh M.
• Application Number:
  US09/487,296
• Time in Patent Office: 1,385 Days
• Field of Search: 345/84, 345/85, 345/86, 345/108, 345/111, 345/105, 345/75.2, 345/74.1, 359/295, 359/291, 359/290, 359/292-294
• US Class Current: 345/84
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 3/3473 based on light coupled out of a light guide, e.g. due to scattering, by contracting the light guide with external means

Abstract

A light modulation element which has a light guide body 11 for guiding light from a light source and a flexible thin film 12 having a phosphor 13 being provided facing the light guide body 11. The distance between the flexible thin film 12 and the light guide body 11 is changed by the electromechanical operation and light emission of the phosphor 13 excited by the guided light is controlled.

Claims

1. A light modulation element comprising:

a light guide body for guiding light from a light source, and

a flexible thin film having a fluorescent material being formed opposing to said light guide body, wherein;

distance between said flexible thin film and said light guide body is changed by electromechanical operation so that light emission of the fluorescent material being excited by the guided light is controlled.

2. The light modulation element as claimed in claim 1, wherein the electromechanical operation is performed by generating an electrostatic force between said flexible thin film and said light guide body.

3. The light modulation element as claimed in any one of claims 1 to 2, wherein said light guide body is formed with a first electrode, said flexible thin film is formed with a second electrode, and a voltage is applied to the first electrode and the second electrode so as to generate an electrostatic force.

4. The light modulation element as claimed in any one of claims 1 to 2, wherein the fluorescent material is a fluorescent layer formed on a surface of said flexible thin film.

5. The light modulation element as claimed in any one of claims 1 to 2, wherein said flexible thin film is made of a resin material and the fluorescent material made of a fluorescent pigment of fine particles is mixed in said flexible thin film.

6. The light modulation element as claimed in any one of claims 1 to 2, wherein said flexible thin film is made of a resin material and the fluorescent material made of an organic fluorescent dye is melted into said flexible thin film.

7. The light modulation element as claimed in any one of claims 1 to 2, wherein said flexible thin film is formed with a reflection film for reflecting light emitted by the fluorescent material toward said light guide body.

8. The light modulation element as claimed in claim 7, wherein the reflection film is used as a second electrode.

9. The light modulation element as claimed in any one of claims 1 to 2, wherein a filter layer for allowing light from the light source to pass through and reflecting light emitted by the fluorescent material is placed between the fluorescent material of said flexible thin film and said light guide body.

10. The light modulation element as claimed in any one of claims 1 to 2, wherein light from the light source is guided from a side of said light guide body.

11. The light modulation element as claimed in any one of claims 1 to 2, wherein light from the light source is guided from a surface of said light guide body on an opposite side to said flexible thin film.

12. The light modulation element as claimed in any one of claims 1 to 2, wherein said light guide body is an optical waveguide.

13. The light modulation element as claimed in claim 12 comprising:

a plurality of parallel optical waveguides formed on a substrate;

a plurality of light sources which can be controlled separately with at least one of the optical waveguides made to correspond to one pixel; and

a plurality of flexible thin films orthogonal to the optical waveguides, wherein

the quantity of light from the light source is changed and light emission of the fluorescent material excited is controlled by the electromechanical operation of the flexible thin film.

14. The light modulation element as claimed in claim 13, wherein the light source is a light emission array element.

15. The light modulation element as claimed in claim 13, wherein the light source is made up of a light emission body and a light modulation array element.

16. The light modulation element as claimed in any one of claims 1 to 2, wherein said light guide body is a light guide plate.

17. The light modulation elements as claimed in claim 16, wherein the light modulation elements are arranged in one-dimensional or two-dimensional matrix wherein the first electrodes and the second electrodes are disposed in stripe shape orthogonal to each other, each of said light modulation elements is formed at each of the intersection points of the first electrodes and the second electrodes so that a simple matrix drive is executed.

18. The light modulation elements as claimed in claim 16, wherein the light modulation elements are arranged in one-dimensional or two-dimensional matrix wherein either the first electrode or the second electrode is used as a pixel electrode, a switch mechanism for supplying an image signal to the pixel electrode is provided for each of said light modulation elements so that an active matrix drive is executed.

19. The light modulation element as claimed in any one of claims 1 to 2, wherein the guided light is ultraviolet light.

20. The light modulation element as claimed in any one of claims 1 to 2, wherein a shield part is provided in an area other than the light emission part of the fluorescent material.

21. The light modulation element as claimed in any one of claims 1 to 2, wherein the guided light is single-color light and wherein the fluorescent material comprises a plurality of different luminescent colors.

22. An exposure unit using a light modulation element as claimed in any one of claims 1 to 2.

23. A flat-panel display unit using a light modulation element as claimed in any one of claims 1 to 2.