Optical modulator, display device and manufacturing method for same

• US 7,034,981 B2
• Filed: 01/15/2004
• Issued: 04/25/2006
• Est. Priority Date: 01/16/2003
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Makigaki, Tomohiro
• Primary Examiner(s): Dang, Hung Xuan
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US10/758,700
• Publication Number:
  US 20040184134A1
• Time in Patent Office: 831 Days
• Field of Search: 359/290, 359/291, 359/292, 359/245, 359/248, 359/223, 359/224, 359/332, 359/237, 359/295, 359/298, 353/30, 353/31, 353/97, 353/98, 353/99
• US Class Current: 359/290
• 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 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24

Abstract

An optical modulator is provided which can be manufactured by means of a simple process, and a display device, and a method of manufacturing same. The optical modulator comprises a first substrate having a movable reflective film that oscillates in accordance with the application of an electrostatic force; a light-transmitting second substrate disposed so as to oppose the first substrate and formed with a transparent electrode for applying the electrostatic force, in a position corresponding to the movable reflective film; and a cavity section, demarcated by the first substrate and the second substrate, for restricting the range of oscillation of the movable reflective film. By forming a movable reflective film by a portion of the substrate and determining the range of oscillation of the movable reflective film by the interval between the substrates, an optical modulator of high durability and high precision can be obtained.

Claims

1. An optical modulator comprising:

a first substrate having at least one first groove on one face thereof, said at least one first groove having a movable reflective film that oscillates in accordance with an electrostatic force formed on the bottom face thereof; and

a light-transmitting second substrate opposing said first substrate and having at least one second groove provided on the face thereof opposing said first substrate, said at least one second groove extending in a direction approximately orthogonal to said at least one first groove and having a transparent electrode formed on the bottom face thereof;

wherein said movable reflective film and said transparent electrode form a picture element at an intersection of said first and second grooves.

2. The optical modulator according to claim 1, wherein said movable reflective film is formed from either a conductive film, or a semiconductor film doped with an impurity, or a dielectric film, or a laminated film combining these films.

3. The optical modulator according to claim 1, wherein said first substrate is formed from a semiconductor substrate.

4. The optical modulator according to claim 3, wherein said first substrate is formed from a semiconductor substrate of one polarity, and said movable reflective film is formed from a semiconductor film of the other polarity.

5. The optical modulator according to claim 3, wherein said semiconductor substrate is a silicon substrate.

6. The optical modulator according to claim 1, wherein said first substrate and said second substrate are bonded together by anodic bonding.

7. The optical modulator according to claim 1, wherein said second substrate is made of borosilicate glass.

8. The optical modulator according to claim 1, wherein a light absorber is formed on the upper face of said transparent electrode.

9. A display device formed by incorporating an optical modulator according to claim 1.