GRID POLARIZER AND PHOTO-ALIGNMENT DEVICE

• US 20170017027A1
• Filed: 03/10/2015
• Published: 01/19/2017
• Est. Priority Date: 03/11/2014
• Status: Abandoned Application

• Current Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Original Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Inventors: TSURUOKA, Kazuyuki, ARAKI, Ryuhei, NAWAKI, Yohei
• Application Number:
  US15/124,616
• Publication Number:
  US 20170017027A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation

Abstract

A stripe-shaped grid provided on a transparent substrate is made from dielectrics or semiconductors. For each linear segment of the grid, a gap (t) on one side of the linear segment, and an opposite gap (T) on an opposite side of the linear segment materially satisfy the relation t<T in a periodic fashion. The phase of s-polarized light propagating between two linear segments that are adjacent to each other over the narrow gap (t) is delayed by at least π/2 relative to s-polarized light propagating between two linear segments that are adjacent to each other over the wider gap (T). As a result, the former s-polarized light and the latter s-polarized light weaken each other and become attenuated.

Claims

1. A grid polarizer comprising:

a transparent substrate; and

a stripe-shaped grid provided on the transparent substrate, the grid including a plurality of linear segments,

the grid being made from dielectrics or semiconductors,

the grid being having portions that satisfy, in effect, relation of t<

T in a periodic fashion, where for each said linear segment of the grid, t represents a first gap between the linear segment concerned and an adjacent linear segment on one side of the linear segment concerned, and T represents a second gap between the linear segment concerned and another adjacent linear segment on an opposite side of the linear segment concerned,

a ratio of t/T having a value that causes a phase of a dense part propagating light to delay at least π

/2 relative to a phase of a coarse part propagating light, where polarized light that has an electric field component in a length direction of each said linear segment of the grid is s-polarized light, the s-polarized light propagating between two linear segments that are adjacent to each other over the first gap t is the dense part propagating light, and the s-polarized light propagating between two linear segments that are adjacent to each other over the second gap T is the coarse part propagating light.

2. The grid polarizer according to claim 1, wherein the grid includes a plurality of pairs of said linear segments provided on the transparent substrate, with each said pair being constituted by two adjacent said linear segments,

the s-polarized light propagating between the two linear segments of each said pair being the dense part propagating light, and a distance between the two linear segments of each said pair being the first gap t,

the s-polarized light propagating between each two adjacent pairs being the coarse part propagating light, and a distance between the each two adjacent pairs being the second gap T,

the first gap t being a distance measured at a light exit of the dense part propagating light, and

the second gap T being a distance measured at a light exit of the coarse part propagating light.

3. The grid polarizer according to claim 2, wherein the distance between the two linear segments in each said pair gradually decreases in a propagating direction of the dense part propagating light.

4. A photo-alignment apparatus comprising:

a light source; and

a grid polarizer according to claim 1, the grid polarizer being disposed between a light irradiation area, where a photo-alignment film is placed, and the light source.

5. The grid polarizer according to claim 2, wherein the distance between the two linear segments in each said pair is constant in a propagating direction of the dense part propagating light.

6. The grid polarizer according to claim 1, wherein the first gap t is from 30 nm to 40 nm.

7. The grid polarizer according to claim 1, wherein the grid is made from titanium oxide, and the transparent substrate is made from silica.

8. The grid polarizer according to claim 1, wherein said plurality of linear segments stand vertically from the transparent substrate.

9. The grid polarizer according to claim 1, wherein said plurality of linear segments stand slant from the transparent substrate.

10. A photo-alignment apparatus comprising:

a light source; and

a grid polarizer according to claim 2, the grid polarizer being disposed between a light irradiation area, where a photo-alignment film is placed, and the light source.

11. A photo-alignment apparatus comprising:

a light source; and

a grid polarizer according to claim 3, the grid polarizer being disposed between a light irradiation area, where a photo-alignment film is placed, and the light source.

12. A grid polarizer comprising:

a transparent substrate; and

a stripe-shaped grid provided on the transparent substrate, the grid being made from dielectrics or semiconductors, the grid including a plurality of linear segments arranged on the transparent substrate at uneven intervals, the uneven intervals being repeated in a periodic fashion, the uneven intervals including at least one first intervals and a second interval, the uneven intervals being decided such that polarized light beam passing between the linear segments arranged at said at least one first interval delays π

/2 or more, in terms of phase, relative to polarized light beam passing between the linear segments arranged at the second interval.