Polarizing element

• US 6,778,237 B2
• Filed: 01/19/2001
• Issued: 08/17/2004
• Est. Priority Date: 01/21/2000
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Arakawa, Kohei, Ichihashi, Mitsuyoshi
• Primary Examiner(s): NGUYEN, DUNG T
• Application Number:
  US09/764,127
• Publication Number:
  US 20010017676A1
• Time in Patent Office: 1,306 Days
• Field of Search: 349/96, 349/99, 349/100, 349/194, 349/9, 349/37, 359/500
• US Class Current: 349/100
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528

Abstract

A polarizing element provided with a layer including liquid crystals and a polarizer having a transmission axis. The polarizing element of the present invention is structured such that liquid crystal molecules in the aforementioned liquid crystal layer have a chiral smectic texture of a helical configuration with respect to a axis, the axis is not along a direction normal to a surface of the liquid crystal layer (a z-direction), and a direction of an orthogonal projection of the axis onto the surface of the liquid crystal layer is substantially at 90° to the polarizer'"'"'s transmission axis.

Claims

1. A polarizing element comprising:

a layer including liquid crystal molecules; and

a polarizer having a transmission axis,

wherein the liquid crystal molecules have a chiral smectic texture of a helical configuration, an axis of a molecular helix of the helical configuration of each of the liquid crystal molecules is along a direction other than a direction normal to a surface of the layer, and a direction of an orthogonal projection of the axis onto the surface of the layer is substantially at 90°

with respect to the transmission axis of the polarizer.

2. The polarizing element of claim 1, wherein the layer has a chiral smectic C texture.

3. The polarizing element of claim 2, wherein the chiral smectic texture of the helical configuration is formed by liquid crystal molecules which are fixed one of physically and by a chemical reaction.

4. The polarizing element of claim 1, wherein the chiral smectic texture is formed by liquid crystal molecules to be fixed one of physically and by a chemical reaction.

5. The polarizing element of claim 1, wherein the polarizer is one of an iodine-type polarizing plate, a dye-type polarizing plate and a polyvinylene-type polarizing plate, and the polarizer has a degree of polarization of at least 98%.

6. The polarizing element of claim 1, wherein the layer is formed on a transparent substrate.

7. The polarizing element of claim 6, wherein the transparent substrate is formed by one of a cellulose-type resin, a norbornene-type resin and a polycarbonate-type resin.

8. The polarizing element of claim 6, wherein the transparent substrate also serves as a protective film for the polarizer.

9. The polarizing element of claim 1, wherein, of natural light that is incident from the direction normal to the surface of the layer, a linearly polarized light component whose vibration direction is substantially at 90°

to the orthogonal projection is transmitted and a vibration direction of a linearly polarized light component whose vibration direction is substantially parallel to the orthogonal projection is substantially altered by 90°

to be transmitted.

10. The polarizing element of claim 1, wherein the axis forms an oblique angle of from 5°

to 90°

with respect to the direction normal to the surface of the layer.

11. A polarizing element comprising:

a layer including liquid crystal molecules; and

a polarizer having a transmission axis,

wherein, the liquid crystal molecules have a chiral smectic C texture of a helical configuration, an axis of a molecular helix of the helical configuration of each of the liquid crystal molecules is along a direction other than a direction normal to a surface of the layer, a direction of an orthogonal projection of the axis onto the surface of the layer is substantially at 90°

with respect to the transmission axis of the polarizer, and, of natural light that is incident from the direction normal to the surface of the layer, a linearly polarized light component whose vibration direction is substantially at 90°

to the orthogonal projection is transmitted and a vibration direction of a linearly polarized light component whose vibration direction is substantially parallel to the orthogonal projection is substantially altered by 90°

to be transmitted.

12. The polarizing element of claim 11, wherein the chiral smectic C texture is formed by liquid crystal molecules to be fixed one of physically and by a chemical reaction.