Irradiation device for polarized light for optical alignment of a liquid crystal cell element

• US 6,532,047 B1
• Filed: 01/13/2000
• Issued: 03/11/2003
• Est. Priority Date: 10/27/1998
• Status: Expired due to Fees

• Current Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Original Assignee: Ushio Denki Kabushiki Kaisha (Ushio Incorporated)
• Inventors: Oosawa, Osamu, Suzuki, Shinji
• Primary Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US09/482,074
• Time in Patent Office: 1,153 Days
• Field of Search: 349/96, 349/97, 349/98, 359/622, 359/618, 359/619, 359/621, 359/623, 359/626
• US Class Current: 349/96
• CPC Class Codes: G02B 5/3066 involving the reflection of light at a particular angle of incidence, e.g. Brewster's angle
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation

Abstract

An improved irradiation device for polarized light for optical alignment of a liquid crystal cell element includes a lamp, a focusing mirror for focusing of the light of the lamp, an integrator lens, and a polarization element in which the polarization element is made such that several glass plates, which are located parallel to one another at a distance, are tilted by the Brewster angle with reference to the optical axis. The rotary motion of the above described polarization element around the center of the light beam incident in the polarization element (light beam being the axis of rotation), changes the polarization direction of the polarized light with which the alignment layer of the liquid crystal cell element is irradiated. The polarization element may be located in the vicinity of the integrator lens. In addition, the polarization element may be made in such a way that several glass plates which are located parallel and at a distance to one another and which are tilted by the Brewster angle with reference to the optical axis of the incident light beam, are each combined with one another in a V-shape and their apex lines pass through the center of the light beam.

Claims

1. An irradiation device for providing polarized light for optically aligning a liquid crystal cell element comprising:

a lamp adapted to emit a light;

a focusing mirror adapted to focus the light of said lamp into a light beam;

an integrator lens adapted to integrate the light beam from said focusing mirror; and

a polarization element for polarizing the light beam in a polarization direction, said polarization element having a plurality of glass plates which are located parallel to and at a distance from one another, said plurality of glass plates being tilted by a Brewster angle with respect to an optical axis of the light beam;

wherein said polarization element is rotatably mounted to rotate about the optical axis of the light beam to change the polarization direction of the light beam which irridates an alignment layer of the liquid crystal cell element.

2. An irradiation device of claim 1, wherein said polarization element is located proximate to said integrator lens.

3. An irradiation device of claim 1, wherein each of said plurality of glass plates of said polarization element are joined with one other of said plurality of glass plates in a V-shape in a manner that apex lines formed where said glass plates are joined are positioned at a substantial center of the light beam.

4. An irradiation device of claim 3, wherein said plurality of glass plates of said polarization element which are joined in a V-shape are arranged into a first group and a second group in which the apex lines of the V-shapes of said first group are brought into alignment with the apex lines of the V-shapes of said second group, and the V-shapes of said first group point in a direction different from the V-shapes of said second group.

5. An irradiation device of claim 4, wherein said plurality of glass plates of said polarization element which are joined in a V-shape are joined at a connecting surface defined by a plane in which an angle of incidence with reference to the optical axis is 90°

.

6. An irradiation device of claim 3, wherein said plurality of glass plates of said polarization element which are joined in a V-shape are joined at a connecting surface defined by a plane in which an angle of incidence with reference to the optical axis is 90°

.

7. The irradiation device according to claim 1, further comprising

a first lens located on an outlet side of the integrator lens and from which parallel beams of light emerge; and

a second lens which converts the parallel beams emerging from the first lens into nonparallel scattered light;

wherein said polarization element is located in an optical path between the first lens and the second lens.