Polarizing beam splitters providing high resolution images and systems utilizing such beam splitters

• US 10,345,610 B2
• Filed: 11/23/2016
• Issued: 07/09/2019
• Est. Priority Date: 11/28/2011
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Carls, Joseph C., Lee, Seong Taek, Teo, Yeow Leng, Chan, Kin Sheng, Cheng, Xiaohui
• Primary Examiner(s): Gordon, Steven Whitesell
• Assistant Examiner(s): Brooks, Jerry L
• Application Number:
  US15/359,653
• Publication Number:
  US 20170075126A1
• Time in Patent Office: 958 Days
• Field of Search: 353 20
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks
• CPC Class Codes: G03B 21/14 Details

Abstract

Polarizing beam splitters and systems incorporating such beam splitters are described. More specifically, polarizing beam splitters and systems with such beam splitters that incorporate multilayer optical films and reflect imaged light towards a viewer or viewing screen with high effective resolution are described.

Claims

1. A multilayer reflective polarizer substantially transmitting a first polarization state and substantially reflecting an orthogonal second polarization state, the multilayer reflective polarizer capable of reflecting an imaged light toward a viewer or screen, the effective pixel resolution of the imaged light being less than 12 microns after reflection from the reflective polarizer.

2. The multilayer reflective polarizer of claim 1, wherein the effective pixel resolution of the imaged light is less than 9 microns after reflection from the multilayer reflective polarizer.

3. The multilayer reflective polarizer of claim 1, wherein the effective pixel resolution of the imaged light is less than 6 microns after reflection from the multilayer reflective polarizer.

4. The multilayer reflective polarizer of claim 1 having a surface roughness Ra of less than 45 nm or a surface roughness Rq of less than 80 nm.

5. The multilayer reflective polarizer of claim 1 having a surface roughness Ra of less than 40 nm or a surface roughness Rq of less than 70 nm.

6. The multilayer reflective polarizer of claim 1 having a surface roughness Ra of less than 35 nm or a surface roughness Rq of less than 55 nm.

7. A polarizing beam splitter, comprising the multilayer reflective polarizer of claim 1 disposed between a first cover and a second cover.

8. The polarizing beam splitter of claim 7, wherein the first and second cover comprise glass or plastic.

9. The polarizing beam splitter of claim 7, wherein the first and second covers are attached to the multilayer reflective polarizer with a pressure sensitive adhesive, UV cured adhesive or an optical epoxy.