EXPANDING A PUPIL USING REPLICATION

• US 20190339515A1
• Filed: 05/03/2019
• Published: 11/07/2019
• Est. Priority Date: 05/03/2018
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: THAKUR, Vivek Kumar, FERRI, John M., RANCURET, Paul L.
• Granted Patent: US 10,642,031 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/126 The splitting element being a prism or prismatic array, including systems based on total internal reflection
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• 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 6/0011 the light guides being planar or of plate-like form
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays

Abstract

The pupil formed by an optical apparatus is expanded by use of a beam splitter to replicate the pupil and a waveguide to further replicate the replicated pupil. An optional rotator element can rotate a portion of the light split by the beam splitter to provide consistent polarization of light in the optical apparatus. In some embodiments, the beam splitter replication expands the pupil in one direction, while the waveguide replication expands the pupil in a second direction.

Claims

1. A pupil expansion apparatus, comprising:

a first beam splitter, configured to receive light from an optic and to replicate a pupil formed by the optic; and

a first waveguide, coupled to the beam first splitter, configured to receive light from the first beam splitter and further expand the pupil of the optic.

2. The pupil expansion apparatus of claim 1,

wherein the first beam splitter is a polarizing beam splitter,

further comprising:

an optical polarization rotator, coupled between the first beam splitter and the first waveguide, configured to rotate polarity of the light received from the first beam splitter.

3. The pupil expansion apparatus of claim 1, wherein the first beam splitter is a dichroic beam splitter.

4. The pupil expansion apparatus of claim 1, wherein the first beam splitter is a plate beam splitter.

5. The pupil expansion apparatus of claim 1, wherein the replication of the pupil by the first beam splitter expands the pupil in a first direction of a two-dimensional coordinate system.

6. The pupil expansion apparatus of claim 1, further comprising a second waveguide, coupled to the first beam splitter, configured to receive light from the first beam splitter.

7. The pupil expansion apparatus of claim 1, further comprising a second beam splitter, coupled to the first beam splitter and configured to receive light from the first beam splitter and transmit a first portion of the light to the first waveguide and a second portion of the light to a second waveguide.

8. The pupil expansion apparatus of claim 7, wherein the first beam splitter and the second beam splitter are of different types.

9. An optical apparatus, comprising:

an optical projection system forming a pupil;

a first beam splitter, coupled to the optical projection system and configured to replicate the pupil; and

a first waveguide, coupled to the first beam splitter and configured to replicate the replicated pupil.

10. The optical apparatus of claim 9,

wherein the first beam splitter is a polarizing beam splitter,

further comprising:

an optical polarization rotator, coupled between the first beam splitter and the first waveguide, configured to rotate polarity of light received from the first beam splitter.

11. The optical apparatus of claim 9, wherein the first beam splitter is a dichroic beam splitter.

12. The optical apparatus of claim 9,

wherein the replication of the pupil by the first beam splitter is in a first direction of a two-dimensional coordinate system, and

wherein the replication of the pupil by the first waveguide is in a second direction of the two-dimensional coordinate system.

13. The optical apparatus of claim 9, wherein the first beam splitter is a prism.

14. The optical apparatus of claim 9, further comprising a second waveguide, coupled to the first beam splitter, configured to receive light from the first beam splitter.

15. The optical apparatus of claim 9, further comprising a second beam splitter, coupled to the first beam splitter and configured to receive light from the first beam splitter and transmit a first portion of the light to the first waveguide and a second portion of the light to a second waveguide.

16. The optical apparatus of claim 15, wherein the first beam splitter and the second beam splitter are of different types.

17. A method of expanding a pupil of an optical apparatus, comprising:

splitting light projected by the optical apparatus using a first beam splitter, replicating the pupil formed by the optical apparatus in a first direction of a two-dimensional coordinate system; and

replicating the pupil of the optical apparatus in a second direction of the two-dimensional coordinate system by a first waveguide optically coupled to the first beam splitter.

18. The method of claim 17, further comprising:

Splitting, by a second beam splitter, light output by the first beam splitter, further replicating the pupil of the optical apparatus; and

replicating the pupil of the optical apparatus further by a second waveguide optically coupled to the second beam splitter.

19. The method of claim 18, activating the first waveguide and the second waveguide at alternate time periods.

20. The method of claim 17, wherein splitting light projected by the optical apparatus comprises splitting light based on wavelengths of the light.