Polarization Conversion System for a PICO-Projector

US 20130194556A1

(19) United States (12) Patent Application Publication (10) Pub. No.: US 2013/0194556 A1 CHI et al. (54)

(43) Pub. Date:

POLARIZATION CONVERSION SYSTEM

Aug. 1, 2013

Publication Classi?cation

FOR A PICO-PROJECTOR

(5 1) Int. Cl. G02B 27/28 G03B 21/14

(71) Applicant: Citizen Finetech Miyota Co., LTD, Miyota (JP) _

(72)

(52)

(2006.01) (2006.01)

US. Cl.

Inventors: Wanll CHI, Longmom, CO (US);

CPC ............ .. G02B 27/285 (2013.01); G03B 21/14

Michael J. O’Callaghan, Louisville, CO

(201301)

(US)

USPC ........................................... .. 353/121; 362/19

(73) Assignee: Citizen Finetech Miyota Co., LTD,

(57)

Miyota (JP)

21

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ABSTRACT .

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An 1llummat1on system for a p1co-pro] ector that prov1des polarization conversion includes the combination of an opti cal element With a series of stacked, elongated PBSs, Where

1' N '2 13/756 225 0 ’ _

alternate ones of the PBSs have a half-Wave plate ?lm applied

(22)

Flled'

Jan‘ 31’ 2013

to a back side thereof and a retarder stack ?lm (RSF) that ?ips

(60)

Related U's' Apphcatlon Data Provisional application No. 61/593,708, ?led on Feb. 1, 2012.

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LED Die Array

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or passes different linear polarization orientations based on

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the Wavelength of light. This combination is placed at a posi tion in the illumination system Where the impinging light is collimated to at least some degree.

Patent Application Publication

Aug. 1, 2013 Sheet 1 0f 5

US 2013/0194556 A1

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Patent Application Publication

Aug. 1, 2013 Sheet 4 0f 5

US 2013/0194556 A1

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