Tilted dichroic polarizing beamsplitter

Patent metadata

Field	Value
Publication number	US-10139645-B2
Application number	US-201715664136-A
Country	US
Kind code	B2
Filing date	Jul 31, 2017
Priority date	Oct 24, 2011
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

The disclosure generally relates to beamsplitters useful in color combiners, and in particular color combiners useful in small size format projectors such as pocket projectors. The disclosed beamsplitters and color combiners include a tilted dichroic reflective polarizer plate having at least two dichroic reflective polarizers tilted at different angles relative to incident light beams, with light collection optics to combine at least two colors of light.

First claim

What is claimed is:

1. A tilted polarizing beam splitter, comprising:
a first prism comprising a first diagonal face;
a second prism comprising a second diagonal face;
and a plurality of spaced apart reflective polarizers stacked between and bonded to each other and the first and second diagonal faces and comprising:
a first reflective polarizer configured to reflect a first polarization state of a first color light, transmit an orthogonal second polarization state of the first color light, and transmit the first polarization state of second and third colors;
a second reflective polarizer configured to reflect the first polarization station of the second color light, transmit the second polarization state of the second color light, and transmit the first polarization state of the third color; and
a third reflective polarizer configured to reflect the first polarization station of the third color light and transmit the second polarization state of the third color light,
wherein at least one of the first, second and third reflective polarizers is titled with respect to the other two.

2. The tilted polarizing beam splitter, wherein each of the first, second and third reflective polarizers is titled with respect to the other two.

3. The tilted polarizing beam splitter, wherein the first color is a red color, the second color is a green color, and the third color is a blue color.

4. The tilted polarizing beam splitter, wherein at least one of the first, second and third reflective polarizers comprises a multilayer optical film.

5. The tilted polarizing beam splitter, wherein at least one of the first, second and third reflective polarizers is a wire grid polarizer.

Assignees

• 3M Innovative Properties Co

Inventors

• Poon Yarn Chee
• Ouderkirk Andrew J
• Watson Philip E
• Cheng Xiaohui
• Tan Kim Leong
• Willett Stephen J

Classifications

• G02F2001/13355

  Physics · mapped topic

• G02B27/145

  having sequential partially reflecting surfaces · CPC title

• G02F1/133533

  Colour selective polarisers (G02F1/1347 takes precedence) · CPC title

• G03B33/06

  by additive-colour projection apparatus · CPC title

• H04N9/3108

  by using a single electronic spatial light modulator · CPC title