Optical system

Patent metadata

Field	Value
Publication number	US-12216262-B2
Application number	US-202117482762-A
Country	US
Kind code	B2
Filing date	Sep 23, 2021
Priority date	Mar 31, 2017
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

An optical system including one or more optical lenses, at least one retarder layer, a reflective polarizer, and a partial reflector is provided. The at least one retarder layer may include first and second retarder layers having different wavelength dispersion curves. The at least one retarder layer may include a first retarder layer having a non-uniform fast axis orientation and/or a non-uniform retardance.

First claim

What is claimed is:

1. An optical system for displaying an object to a viewer, comprising:
one or more optical lenses having at least one curved major surface;
a reflective polarizer disposed on and conforming to a first major surface of the one or more optical lenses, the reflective polarizer substantially reflecting light having a first polarization state and substantially transmitting light having an orthogonal second polarization state;
a partial reflector disposed on and conforming to a different second major surface of the one or more optical lenses, the partial reflector having an average optical reflectance of at least 20%;
a first retarder layer disposed on and conforming to a third major surface of the one or more optical lenses; and
a second retarder layer disposed on and conforming to a fourth major surface, different than the third major surface, of the one or more optical lenses, such that relative to the first polarization state, the first retarder layer has a substantially uniform orientation and uniform retardance across the first retarder layer, and the second retarder layer has a substantially non-uniform retardance and non-uniform orientation across the second retarder layer.

2. The optical system of claim 1 , wherein the first retarder layer has a first wavelength dispersion curve and the second retarder layer has a different second wavelength dispersion curve.

3. The optical system of claim 1 , wherein the first retarder layer comprises a first spin-coated retarder layer having a smaller average first physical thickness and the second retarder layer comprises a second spin-coated retarder layer having a greater average second physical thickness.

4. The optical system of claim 1 having an optical axis intersecting the first retarder layer at a first origin and the reflective polarizer at a second origin, a light ray propagating along the optical axis passing through the one or more optical lenses, the partial reflector, the reflective polarizer and the first retarder layer without being substantially refracted, the optical system further comprising a display, wherein for a plurality of chief light rays emitted by the display, each chief light ray having the first polarization state at a predetermined wavelength and a different separation from the optical axis, the first retarder layer converts the chief light ray to a circularly polarized light.

5. The optical system of claim 1 having an optical axis intersecting the first retarder layer at a first origin and the reflective polarizer at a second origin, a light ray propagating along the optical axis passing through the one or more optical lenses, the partial reflector, the reflective polarizer and the first retarder layer without being substantially refracted, wherein each location on the reflective polarizer has corresponding mutually orthogonal pass and block polarization states, and wherein for a light ray having a predetermined wavelength and the block polarization state of the reflective polarizer at the second origin and first incident on the first retarder layer at the first origin and making an angle θ with the optical axis, the light ray is substantially reflected when first incident on the reflective polarizer at a first location and substantially transmitted when second incident on the reflective polarizer at a second location,
a difference between the polarization state of the light ray and the pass polarization state of the reflective polarizer at the second location being greater when θ is zero and less when θ is not zero.

Assignees

• 3M Innovative Properties Company

Inventors

• Steiner Michael L
• Ouderkirk Andrew J
• Wong Timothy L
• Yun Zhisheng
• Etter Jo A
• Benoit Gilles J
• Le John D
• Mcdowell Erin A

Classifications

• G02B27/283

  used for beam splitting or combining · CPC title

• G02B5/3083

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title

• G02B17/0856 Primary

  comprising a refractive element with a reflective surface, the reflection taking place inside the element, e.g. Mangin mirrors · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title