Spatial light modulator featured with an anti-reflective structure

• US 20080013157A1
• Filed: 07/11/2007
• Published: 01/17/2008
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Ichikawa, Hirotoshi, Watanabe, Kazuhiro, Ishii, Fusao, Horikawa, Yoshiaki
• Granted Patent: US 7,542,197 B2
• Time in Patent Office: Days
• US Class Current: 359/298
• CPC Class Codes: G02B 1/118 having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures
• 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: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 2201/38 Anti-reflection arrangements
• CPC Class Codes: G02F 2203/12 spatial light modulator
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A spatial light modulator supported on a device substrate includes a plurality of light modulation elements to modulate a light emitted from a light source. The spatial light modulator and the device substrate further comprises a cyclic structure on a surface of the spatial light modulator and/or the device substrate for preventing a reflection of the incident light from the cyclic structure. In an exemplary embodiment the cyclic structure includes cyclic structural elements having a distance between two cyclic elements shorter than the wavelength of an incident light for preventing a reflection of the incident light from the cyclic structure,

Claims

1. An image projection system comprising a spatial light modulator formed on a device substrate for controlling a light modulation element to modulate an incident light emitted from a light source, comprising

a cyclic structure comprising cyclic structural elements having a distance between two cyclic elements shorter than the wavelength of an incident light for preventing a reflection of said incident light from said cyclic structure.

2. The image projection system according to claim 1 wherein:

said cyclic structure is disposed on said spatial light modulator.

3. The image projection system according to claim 1 wherein:

said cyclic structure is disposed on said device substrate.

4. The image projection system according to claim 1 wherein:

said spatial light modulator is contained in a package and said cyclic structure is disposed on said package.

5. The image projection system according to claim 1, wherein

said cyclic structure having a cross sectional shape of substantially at least two side-by-side vertical triangles.

6. The image projection system according to claim 5, wherein

said side-by-side triangles is characterized by:

λ

>

P>

λ

/2, and
H/W>

3, where

the P is a pitch between top vertex points of the side-by-side triangles, the λ

is the wavelength of the incident light, the H is the height of the side-by-side triangles, and the W is a base width of the side-by-side triangles.

7. The image projection system according to claim 1, comprising

the cyclic structure is disposed on one side of a surface of the device substrate.

8. The image projection system according to claim 1, comprising

the cyclic structure is disposed on both sides of a surface of the device substrate.

9. The image projection system according to claim 1, comprising

the spatial light modulator comprising a plurality of mirror elements for modulating the incident light wherein said structure is disposed on one side of a surface of the mirror elements.

10. An image display apparatus comprising a spatial light modulator modulating an incident light emitted from a light source, comprising

a device substrate for supporting said spatial light modulator thereon wherein said device substrate further includes a cyclic structure comprising cyclic structural elements having a distance between two cyclic elements shorter than the wavelength of said incident light for preventing a reflection of said incident light from said cyclic structure.

11. The image display apparatus according to claim 10, further comprising

a light source for projecting a polarized incident light, and

the cyclic structure is oriented in one direction parallel with a polarization direction of the polarized incident light.

12. The image display apparatus according to claim 10, further comprising

a light source for projecting a polarized incident light, and

the cyclic structure is oriented in one direction perpendicular to a polarization direction of the polarized incident light.

14. The method according to claim 10, wherein

said step of forming said cyclic structure further comprising forming said cyclic structure with cyclic structural elements having a distance between two cyclic elements shorter than the wavelength of an incident light for preventing a reflection of said incident light from said cyclic structure.

13. A method of manufacturing a spatial light modulator for modulating an incident light projected thereon comprising

applying an imprinting method, etching method or sol-gel method for forming a cyclic structure on a surface of said spatial light modulator for preventing a reflection of said incident light from said cyclic structure.