Spatially patterned polarization compensator

• US 20050151905A1
• Filed: 02/01/2005
• Published: 07/14/2005
• Est. Priority Date: 01/07/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kurtz, Andrew F., Silverstein, Barry D., Mi, Xiang-Dong
• Granted Patent: US 7,023,512 B2
• Time in Patent Office: Days
• US Class Current: 349/117
• CPC Class Codes: G02B 27/18 for optical projection, e.g. combination of mirror and condenser and objective photographic, cine and overhead projectors G03B21/00; photographic projection printing G03B27/32; photolithographic projectors G03F7/20; projection television H04N5/74; colour projection television H04N9/31
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28
• CPC Class Codes: H04N 9/3191 Testing thereof testing of displays in general G09G3/006

Abstract

A modulation optical system (40) provides modulation of an incident light beam. A wire grid polarization beamsplitter (240) receives the beam of light (130) and transmits a beam of light having a first polarization, and reflects a beam of light having a second polarization orthogonal to the first polarization. Sub-wavelength wires (250) on the wire grid polarization beamsplitter face a reflective spatial light modulator. The reflective spatial light modulator receives the polarized beam of light and selectively modulates the polarized beam of light to encode data thereon. The reflective spatial light modulator reflects back both the modulated light and the unmodulated light to the wire grid polarization beamsplitter. The wire grid polarization beamsplitter separates the modulated light from the unmodulated light. A compensator (260) is located between the wire grid polarization beamsplitter and the reflective spatial light modulator (210). The compensator conditions the polarization states of the oblique and skew rays of the modulated beam and includes a spatially variant retardance that corrects for a spatially variant retardance of the reflective spatial light modulator.

Claims

1. A spatially patterned polarization compensator, comprising an optical structure fabricated with a spatially variant retardance that corresponds to the spatially variant retardance of a spatial light modulator, such that when said patterned polarization compensator and said spatial light modulator are used in combination, a nominally spatially uniform retardance results.

2. A spatially patterned polarization compensator according to claim 1 which is fabricated with liquid crystal polymer materials.

3. A spatially patterned polarization compensator according to claim 1 which is fabricated with inorganic materials.

4. A spatially patterned polarization compensator, fabricated with the assistance of a pre-existing spatial light modulator having a spatially variant retardance, such that said spatially patterned polarization compensator has a spatially variant retardance that corresponds to the spatially variant retardance of said pre-existing spatial light modulator, with the result that when said patterned polarization compensator and said pre-existing spatial light modulator are used in combination within a light beam, a nominally spatially uniform retardance is provided.

5. A spatially patterned polarization compensator, comprising an optical structure fabricated with a spatially variant retardance that corresponds to the spatially variant retardance of a pre-existing spatial light modulator, such that when said patterned polarization compensator and said pre-existing spatial light modulator are used in combination within a light beam of a given color band, a nominally spatially uniform net retardance results.

6. A spatially patterned polarization compensator, comprising an optical structure fabricated with a spatially variant retardance that corresponds to the spatially variant retardance of a spatial light modulator, such that when said patterned polarization compensator and said spatial light modulator are used in combination within a light beam, the net retardance of the combination is nominally spatially uniform across the full width of said spatial light modulator.

7. A spatially patterned polarization compensator, comprising an optical structure fabricated with a spatially variant retardance that corresponds to the spatially variant retardance of a spatial light modulator, such that when said patterned polarization compensator and said spatial light modulator are used in combination within a light beam of a given color band, a nominally spatially uniform net retardance results.