Display device

• US 6,249,370 B1
• Filed: 09/16/1999
• Issued: 06/19/2001
• Est. Priority Date: 09/18/1998
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Okada, Shigeki, Takeuchi, Yukihisa, Shimogawa, Natsumi, Takahashi, Masao
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/397,229
• Time in Patent Office: 642 Days
• Field of Search: 359/227, 359/222, 359/224, 359/226, 359/230, 359/245, 359/320, 359/322, 359/323, 359/290, 359/291, 359/295, 345/84, 345/85, 345/108, 345/109
• US Class Current: 359/291
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means

Abstract

Disclosed is a display device comprising a light-shielding plate including a metal thin film formed on a first principal surface of an optical waveguide plate for introducing the light thereinto and including light-transmitting sections formed at portions corresponding to picture elements to make penetration through the optical waveguide plate, and shutter sections provided opposingly to a second principal surface of the light-shielding plate, for selectively intercepting the light transmitted through the light-transmitting sections in accordance with an input signal. The shutter sections include actuator elements provided corresponding to the large number of light-transmitting sections so that the light to be transmitted through the light-transmitting sections is intercepted substantially in synchronization with the operation of the actuator elements. Accordingly, it is possible to improve the contrast and improve the image quality of a displayed image.

Claims

1. A display device comprising:

a light-shielding plate;

light-transmitting sections formed on said light-shielding plate corresponding to a large number of picture elements, for transmitting light toward a first principal surface of said light-shielding plate; and

a shutter means provided opposingly to a second principal surface of said light-shielding plate, for selectively intercepting said light to be transmitted through each of said light-transmitting sections, in response to an input signal.

2. The display device according to claim 1, wherein said shutter means comprises:

an actuator element provided corresponding to each of said large number of light-transmitting sections; and

a shutter mechanism for intercepting said light to be transmitted through said each of said light-transmitting sections substantially in synchronization with operation of said actuator element.

3. The display device according to claim 2, wherein:

said shutter mechanism includes a displacement-transmitting section formed on said actuator element; and

said displacement-transmitting section includes a light-shielding section provided at a portion opposed to said light-shielding plate.

4. The display device according to claim 3, wherein said light-shielding section of said displacement-transmitting section is provided at a position at which an optical path communicating with the outside through said light-transmitting section is intercepted when said actuator element is operated.

5. The display device according to claim 4, wherein said optical path is intercepted by displacing said light-shielding section with respect to said second principal surface of said light-shielding plate in its normal direction in accordance with said operation of said actuator element.

6. The display device according to claim 2, wherein said actuator element is formed on an actuator substrate made of ceramics.

7. The display device according to claim 6, wherein said actuator substrate is formed as a thin-walled diaphragm section, and said actuator element is formed in an integrated manner thereon.

8. The display device according to claim 6, wherein said actuator substrate has at least one hollow space, a thin-walled portion thereof is formed as a diaphragm section, and said actuator element is formed in an integrated manner thereon.

9. The display device according to claim 6, wherein said actuator element includes a shape-retaining layer for making movement in a direction to make separation and/or approach from said second principal surface of said light-shielding plate in accordance with an applied electric field, and an operating section having at least a pair of electrodes formed on said shape-retaining layer.

10. The display device according to claim 1, wherein said light-shielding plate is arranged such that at least its first principal surface and an inner wall surface of said light-transmitting section are shielded from light.

11. The display device according to claim 10, wherein:

said light-shielding plate is constructed such that a first principal surface of an optical waveguide plate for introducing said light thereinto and said inner wall surface of said light-transmitting section are shielded from light; and

a light-introducing section for releasing said light introduced into said optical waveguide plate as leakage light is provided at a portion of a second principal surface of said optical waveguide plate in the vicinity of said light-transmitting section.

12. The display device according to claim 11, wherein said light-introducing section is constructed by a mediating element formed at a portion of said second principal surface of said optical waveguide plate in the vicinity of said light-transmitting section.

13. The display device according to claim 11, wherein a portion of said second principal surface of said optical waveguide plate except for said light-introducing section is shielded from light.

14. The display device according to claim 11, wherein:

a light-emitting section is disposed on a side of said second principal surface of said light-shielding plate; and

said light to be transmitted through said light-transmitting section is generated by radiating said leakage light from said optical waveguide plate onto said light-emitting section.

15. The display device according to claim 14, wherein said light-emitting section is constructed by a light-emitting element or a reflective element provided corresponding to each of said displacement-transmitting sections.

16. The display device according to claim 10, wherein:

a light-emitting section is disposed on a side of said second principal surface of said light-shielding plate; and

said light to be transmitted through said light-transmitting section is generated by radiating said light introduced from the outside onto said light-emitting section.

17. The display device according to claim 16, wherein said light-emitting section is constructed by a light-emitting element or a reflective element provided corresponding to each of said displacement-transmitting sections.