Optical display device

Patent metadata

Field	Value
Publication number	US-10025013-B2
Application number	US-201313791017-A
Country	US
Kind code	B2
Filing date	Mar 8, 2013
Priority date	Mar 9, 2012
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

An optical display device which includes a display panel, and at least one polarizing film including a polyvinyl alcohol-based resin layer disposed on a viewing side with respect to the display panel, and having an optical arrangement forming a cross-Nicol relationship with regard to polarized light entering the polarizing film from the side of the display panel. The polarizing film is produced to have a thickness of 10 μm or less, by a method comprising the steps of: forming a polyvinyl alcohol-based resin layer on a resin substrate; stretching the polyvinyl alcohol-based resin layer integrally with the resin substrate; and dyeing the polyvinyl alcohol-based resin layer using a dichroic material. The polarizing film is disposed in the optical display device in a state in which a surface of the polarizing film as a contact surface with the resin substrate during the production thereof is oriented toward a side opposite to the display panel.

First claim

What is claimed is:

1. An optical display device, comprising
a display panel; and
at least one polarizing film having opposed first and second sides and including a polyvinyl alcohol-based resin layer disposed on a viewing side with respect to the display panel, and having an optical arrangement forming a crossed-Nicols relationship with regard to polarized light entering the at least one polarizing film from the viewing side of the display panel,
wherein
the at least one polarizing film is produced to have a thickness of 10 μm or less, by a method comprising the steps of:
forming a polyvinyl alcohol-based resin layer on a resin substrate;
stretching the polyvinyl alcohol-based resin layer integrally with the resin substrate; and
dyeing the polyvinyl alcohol-based resin layer using a dichroic material,

the at least one polarizing film is disposed in the optical display device in a state in which a surface in which the second side of the at least one polarizing film has a contact surface with the resin substrate during the production thereof which is oriented toward a side opposite to the display panel, and
the at least one polarizing film has a defect on the contact surface of the second side formed during the above steps by a defect in or on the resin substrate from which light is emitted for polarized light entering the optical arrangement, and the emitted light is weaker than light that would be emitted from an identical defect formed on a surface of the first side.

2. The optical display device as defined in claim 1 , which is a liquid crystal display device or an organic EL display device.

3. The optical display device as defined in claim 2 , which is a liquid crystal display device comprising the at least one polarizing film and a second polarizing film each produced to have a thickness of 10 μm or less, by a method comprising the steps of:
forming a polyvinyl alcohol-based resin layer on a resin substrate;
stretching the polyvinyl alcohol-based resin layer integrally with the resin substrate; and
dyeing the polyvinyl alcohol-based resin layer using a dichroic material,
wherein:
the second polarizing film is disposed on a non-viewing side with respect to the display panel, and
the first polarizing film forms the crossed-Nicols relationship with regard to polarized light entering the first polarizing film from the viewing side of the display panel after penetrating through the second polarizing film.

4. The optical display device as defined in claim 3 , wherein the second polarizing film is disposed in a state in which a surface of the second polarizing film has a contact surface with the resin substrate during the production thereof which is oriented toward a side opposite to the display panel.

5. The optical display device as defined in claim 3 , wherein each of the first and second polarizing films comprises a protective layer provided at least on the side opposite to the display panel.

6. The optical display device as defined in claim 5 , which is a VA-mode liquid crystal display device or an IPS-mode liquid crystal display device.

7. The optical display device as defined in claim 6 , which is a VA-mode liquid crystal display device having a VA-mode liquid crystal cell as the display panel, wherein the VA-mode liquid crystal display device further comprises a phase difference film provided between the display panel and the first polarizing film.

8. The optical display device as defined in claim 6 , which is an IPS-mode liquid crystal display device having an IPS-mode liquid crystal cell as the display panel.

9. The optical display device as defined in claim 2 , which is an organic EL display device comprising the display panel, a ¼ wavelength phase difference film, the at least one polarizing film and a protective film which are arranged in this order, the optical arrangement has the crossed-Nicols relationship with regard to polarized light which, after penetrating through the at least one polarizing film from the viewing side and then undergoing a reflection at the display panel, re-enters the at least one polarizing film from the viewing side of the display panel.

10. The optical display device as defined in claim 1 , wherein the at least one polarizing film is produced by:
subjecting both a non-crystallizable ester-based thermoplastic resin substrate and a PVA-based resin layer, applied and formed on the non-crystallizable ester-based thermoplastic resin substrate, to a 2-stage stretching process consisting of preliminary in-air stretching and in-boric-acid-solution stretching; and
subjecting the PVA-based resin layer to a dyeing treatment using a dichroic material.

11. The optical display device as defined in claim 1 , wherein
the display panel includes a liquid crystal cell, and
a first polarizing film of the at least one polarizing film is between the liquid crystal cell and the resin substrate.

12. The optical display device as defined in claim 1 , wherein
the display panel includes an organic El cell, and
a first polarizing film of the at least one polarizing film is between the organic EL cell and the resin substrate.

Assignees

• Nitto Denko Corp

Inventors

• Ikeshima kentaro
• Miyatake Minoru
• Nakano Yuki

Classifications

• G02B5/3033 Primary

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title

• G02F2001/133531

  Physics · mapped topic

• B29C55/026

  of preformed plates or sheets coated with a solution, a dispersion or a melt of thermoplastic material · CPC title

• G02F1/133528

  Polarisers · CPC title

• G02F1/1335

  Structural association of cells with optical devices, e.g. polarisers or reflectors · CPC title