Reflective polarizer and display device having the same

• US 7,557,989 B2
• Filed: 05/16/2006
• Issued: 07/07/2009
• Est. Priority Date: 06/03/2005
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Nelson, Eric W., Cross, Elisa M., Invie, Judith M., Zhang, Wei Feng
• Primary Examiner(s): FINEMAN, LEE A
• Application Number:
  US11/383,672
• Publication Number:
  US 20070014009A1
• Time in Patent Office: 1,148 Days
• Field of Search: None
• US Class Current: 359/489.15
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers

Abstract

A reflective polarizer suitable for use in a display device is disclosed herein. The reflective polarizer includes: a multilayer optical film including alternating layers of first and second polymeric layers that reflects light of a first polarization state and transmits light of a second polarization state, wherein for normally incident light of the second polarization state, the reflective polarizer has an internal percent transmission of at least 95% at 410 nm, and at most 25% at 380 nm. Also disclosed herein is a display device including the reflective polarizer.

Claims

1. A reflective polarizer suitable for use in a display device, the article comprising:

a multilayer optical film comprising alternating layers of first and second polymeric layers, the first and second polymeric layers having refractive indices along an in-plane x-axis that differ sufficiently to substantially reflect light of a first polarization state, the first and second polymeric layers having refractive indices along an in-plane y-axis that are matched sufficiently to substantially transmit light of a second polarization state, wherein the x- and y-axes are orthogonal, wherein at least one of the first and second polymeric layers comprises naphthalate functionality;

a support layer disposed on a first side of the multilayer optical film and adhered thereto by an adhesive layer, the support layer being light transmissive;

wherein at least one of the first and second polymeric layers, the support layer, and the adhesive layer comprises an ultraviolet (UV) absorber that absorbs UV light and transmits visible light, such that for normally incident light of the second polarization state, the reflective polarizer has an internal percent transmission of at least 95% at 410 nm, and at most 25% at 380 nm.

2. A display device comprising:

a display panel,

a light source, and

a reflective polarizer disposed between the display panel and the light source, the reflective polarizer comprising;

a multilayer optical film comprising alternating layers of first and second polymeric layers, the first and second polymeric layers having refractive indices along an in-plane x-axis that differ sufficiently to substantially reflect light of a first polarization state, the first and second polymeric layers having refractive indices along an in-plane y-axis that are matched sufficiently to substantially transmit light of a second polarization state, wherein the x- and y-axes are orthogonal, wherein at least one of the first and second polymeric layers comprises naphthalate functionality;

wherein for normally incident light of the second polarization state, the reflective polarizer has an internal percent transmission of at least 95% at 410 nm, and at most 25% at 380 nm.

3. The display device of claim 2, wherein the display panel is a liquid crystal display panel.

4. The display device of claim 2, wherein the display device is a television.