Apparatuses and methods for providing light

• US 10,209,611 B2
• Filed: 02/05/2016
• Issued: 02/19/2019
• Est. Priority Date: 02/23/2015
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Eskolin, Jan, Piippo, Petri, Jarvenpaa, Toni, Salmimaa, Marja
• Primary Examiner(s): Chowdhury, Sultan
• Application Number:
  US15/552,659
• Publication Number:
  US 20180046070A1
• Time in Patent Office: 1,110 Days
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02F 1/0136 for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation G02F1/0353 takes precedence
• CPC Class Codes: G03B 21/2073 Polarisers in the lamp house peculiar to electronic spatial light modulators H04N9/3197

Abstract

An apparatus including a light source; a pixel control element; and an input transmission polarizer configured to: polarize incident light from the light source into transmitted first and second light portions, wherein the first light portion has a first polarization and the second light portion has a second polarization and wherein the first and second polarizations are orthogonal; to provide the first light portion as input to the pixel control element; and to output the second light portion to provide the second light portion for illumination.

Claims

1. An apparatus comprising:

a light source;

a pixel control element; and

an input transmission polarizer configured to;

polarize incident light from the light source into transmitted first and second light portions, wherein the first light portion has a first polarization and the second light portion has a second polarization and wherein the first and second polarizations are orthogonal;

provide the first light portion as input to the pixel control element, wherein the pixel control element is configured to rotate the polarization of the first light portion based on what is displayed on at least one pixel of the pixel control element; and

output the second light portion to provide the second light portion for illumination, wherein the second light portion is output for illumination external to the apparatus.

2. The apparatus as claimed in claim 1, wherein the input transmission polarizer comprises a polarizing beam splitter.

3. The apparatus as claimed in claim 1, wherein the input transmission polarizer is located between the light source and the pixel control element.

4. The apparatus as claimed in claim 1, further comprising a control mechanism configured to receive the second light portion as an input and to control the transmission ratio of the second light portion.

5. The apparatus as claimed in claim 4 wherein the control mechanism comprises a liquid crystal shutter.

6. The apparatus as claimed in claim 1, further comprising a polarization controller configured to receive light from the light source as an input and to selectively output light having the first or second polarization as an input to the input transmission polarizer.

7. The apparatus as claimed in claim 6, wherein the polarization controller comprises a polarizer and a controllable polarization rotator.

8. The apparatus as claimed in claim 7, wherein the polarization rotator comprises a liquid crystal plate.

9. The apparatus as claimed in claim 6 wherein the polarization controller is configured to be controlled in synchronization with the duty cycle of the pixel control element.

10. The apparatus as claimed in claim 7 further comprising a polarization recycler configured to receive light returned from the polarization controller and to recycle at least a portion of the returned light and output the recycled light to the polarization controller.

11. The apparatus as claimed in claim 1 wherein the pixel control element comprises a reflective microdisplay.

12. The apparatus as claimed in claim 1, wherein the pixel control element comprises a transmissive microdisplay.

13. The apparatus as claimed in claim 1, wherein the apparatus comprises a near-eye display.

14. A method comprising:

providing a light source;

providing a pixel control element; and

providing an input transmission polarizer configured to;

polarize incident light from the light source into transmitted first and second light portions, wherein the first light portion has a first polarization and the second light portion has a second polarization and wherein the first and second polarizations are orthogonal;

provide the first light portion as input to the pixel control element, wherein the pixel control element is configured to rotate the polarization of the first light portion based on what is displayed on at least one pixel of the pixel control element; and

output the second light portion to provide the second light portion for illumination, wherein the second light portion is output for illumination external to the apparatus.

15. The method of claim 14, wherein the input transmission polarizer comprises a polarizing beam splitter.

16. The method of claim 14, wherein the input transmission polarizer is located between the light source and the pixel control element.

17. The method of claim 14, further comprising

providing a control mechanism configured to receive the second light portion as an input and to control the transmission ratio of the second light portion.

18. The method of claim 17, wherein the control mechanism comprises a liquid crystal shutter.

19. The method of claim 14, wherein the pixel control element comprises a reflective microdisplay.

20. The method of claim 14, wherein the pixel control element comprises a transmissive microdisplay.