Micromirror array, manufacturing method for micromirror array, and optical elements used in micromirror array

• US 9,494,716 B2
• Filed: 07/08/2013
• Issued: 11/15/2016
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Juni, Noriyuki
• Primary Examiner(s): CHOI, WILLIAM C
• Application Number:
  US14/413,323
• Publication Number:
  US 20150192709A1
• Time in Patent Office: 1,226 Days
• Field of Search: 359619-624, 359/838, 359/850
• US Class Current: 1/1
• CPC Class Codes: B29D 11/00596 Mirrors
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: G02B 5/0816 Multilayer mirrors, i.e. having two or more reflecting layers G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A manufacturing method for a micromirror array includes: preparing transparent flat substrates; attaching each of the substrates at a predetermined position of a machining stage of a dicing machine; sequentially forming parallel linear grooves arranged at intervals in one surface of each substrate; and stacking the substrates together so that the directions in which the linear grooves of the respective substrates extend are orthogonal to each other as seen in plan view. The substrates are stacked together in a manner selected from the group consisting of: the front surface of one of the substrates and the back surface of the other substrate are joined together for the stacking of the substrates; the front surfaces of the respective substrates are joined together for the stacking of the substrates; and the back surfaces of the respective substrates are joined together for the stacking of the substrates.

Claims

1. A micromirror array comprising:

two optical elements each having a plurality of parallel linear grooves arranged at predetermined spacings and formed in a first surface of a transparent flat substrate, the two optical elements being stacked together so that the directions in which the linear grooves of the respective optical elements extend are orthogonal to each other as seen in plan view, to thereby constitute a single unit,

wherein the two optical elements are stacked together in a manner selected from the group consisting of;

(A) a manner in which the front surface of one of the optical elements where the linear grooves are formed and the back surface of the other optical element where the grooves are not formed are brought into abutment with each other;

(B) a manner in which the front surfaces of the respective optical elements where the linear grooves are formed are brought into abutment with each other; and

(C) a manner in which the back surfaces of the respective optical elements where the grooves are not formed are brought into abutment with each other,

wherein the micromirror array is capable of forming a mirror image of an object to be projected which is disposed on a first surface side of the micromirror array at a spatial position on a second surface side thereof symmetrical to the object with respect to the plane of an element surface of the micromirror array.

2. A micromirror array comprising:

a plurality of parallel linear grooves arranged at predetermined spacings and formed in a first surface of a transparent flat substrate constituting an optical element and in a second surface thereof opposite from the first surface,

wherein the directions in which the linear grooves on the front surface side and the linear grooves on the back surface side extend are orthogonal to each other as seen in plan view,

wherein the micromirror array is capable of forming a mirror image of an object to be projected which is disposed on a first surface side of the micromirror array at a spatial position on a second surface side thereof symmetrical to the object with respect to the plane of an element surface of the micromirror array.

3. A method of manufacturing a micromirror array, comprising:

preparing a transparent flat substrate;

attaching the substrate at a predetermined position of a machining stage of a dicing machine;

sequentially forming a plurality of parallel linear grooves arranged at predetermined intervals in a surface of said substrate by using a rotary blade; and

stacking two substrates where said linear grooves are formed together so that the directions in which the linear grooves of the respective substrates extend are orthogonal to each other as seen in plan view, to thereby constitute a single unit,

wherein the two substrates are stacked together in a manner selected from the group consisting of;

(D) a manner in which the front surface of one of the substrates where the linear grooves are formed and the back surface of the other substrate where the grooves are not formed are joined together for the stacking of the substrates;

(E) a manner in which the front surfaces of the respective substrates where the linear grooves are formed are joined together for the stacking of the substrates; and

(F) a manner in which the back surfaces of the respective substrates where the grooves are not formed are joined together for the stacking of the substrates.

4. A method of manufacturing a micromirror array, comprising:

preparing a transparent flat substrate;

attaching the substrate at a predetermined position of a machining stage of a dicing machine;

sequentially forming a plurality of parallel linear grooves arranged at predetermined intervals in a first surface of said substrate by using a rotary blade;

removing the substrate once from said machining stage to flip the substrate upside down and to thereafter attaching the substrate again at a predetermined position of the machining stage; and

sequentially forming a plurality of parallel linear grooves similar to those in said first surface and arranged at predetermined intervals in a second surface of said substrate by using a rotary blade, so as to extend in a direction orthogonal to the linear grooves in said first surface as seen in plan view.

5. A micromirror array comprising:

two optical elements stacked one on top of the other,

wherein the optical elements comprise a transparent flat substrate comprising a plurality of parallel linear grooves arranged at predetermined spacings formed in a surface thereof,

wherein a “

height-to-width”

ratio of a width of substrate front surface portions lying between adjacent linear grooves to a height of the substrate front surface portions from the bottom of the grooves is not less than 3.0, and

wherein the micromirror array is capable of forming a mirror image of an object to be projected which is disposed on a first surface side of the micromirror array at a spatial position on a second surface side thereof symmetrical to the object with respect to the plane of an element surface of the micromirror array.