Light beam polarization converter for converting an illumination light source

• US 6,587,275 B2
• Filed: 01/19/2001
• Issued: 07/01/2003
• Est. Priority Date: 12/01/2000
• Status: Expired due to Fees

• Current Assignee: Advancewave Technology Incorporated, Slight Opto-Electronics Company Limited, TANG, CNING-HENG (50%)
• Original Assignee: Slight Opto-Electronics Company Limited
• Inventors: Lee, Chih-Kung, Lin, Chih-Ting, Tang, Ching-Heng, Lee, Shu-Sheng
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Harrington, Alicia M.
• Application Number:
  US09/765,948
• Publication Number:
  US 20020105710A1
• Time in Patent Office: 893 Days
• Field of Search: 359/490, 359/495, 359/496, 359/619, 359/620, 359/626, 359/627
• US Class Current: 359/620
• CPC Class Codes: G02B 27/285 comprising arrays of elements, e.g. microprisms
• 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 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence

Abstract

A light beam polarization converter converts non-polarized light beams of an illumination source having a plurality of polarization states into a single polarization state. The light beams from the bottom converged by the lower surface of the under plate and further parallelized by the upper surface thereof enter the converter. After a series of optical processes of polarization splitting, reflection or total reflection, and phase retardation within the converter, the light beams will pass through the converter as light beams of a single polarization state.

Claims

1. A light beam polarization converter for converting an illumination light source having a plurality of polarization states into a polarization light source, comprising:

an under plate having undulated lower and upper surfaces in conjugate to each other for converging and parallelizing the light beams respectively;

a substrate having a ridged upper surface and a ridged lower surface disposed on the under plate;

a phase retardation film of high reflectivity disposed partially on the lower surface of the substrate;

an upper cover having a ridged lower surface, substantially complementary to the ridged upper surface of the substrate and facing therewith, and an upper surface; and

a thin film disposed between the upper cover and the substrate, the index of refraction thereof is different from that of the substrate.

2. The light beam polarization converter according to claim 1, wherein the phase retardation film is a dry film formed by an optical-precision application process.

3. The light beam polarization converter according to claim 1, further comprising an undulated film disposed on the upper surface of the upper cover.

4. The light beam polarization converter according to claim 1, further comprising an anti-reflection film disposed on the undulated lower surface of the under plate.

5. A light beam polarization converter for converting an illumination light source having a plurality of polarization states into a polarization light source, comprising:

an under plate having undulated lower and upper surfaces in conjugate to each other for converging and parallelizing the light beams respectively;

a substrate having a ridged upper surface and a ridged lower surface providing total reflection of the light beams disposed on the under plate;

an upper cover having a ridged lower surface, substantially complementary to the ridged upper surface of the substrate and facing therewith, and an upper surface; and

a thin film disposed between the upper cover and the substrate, the index of refraction thereof is different from that of the substrate.

6. The light beam polarization converter according to claim 5, wherein the phase retardation film is a dry film formed by an optical-precision application process.

7. The light beam polarization converter according to claim 5, further comprising an undulated film disposed on the upper surface of the upper cover.

8. The light beam polarization converter according to claim 5, further comprising an anti-reflection film disposed on the undulated lower surface of the under plate.