LED STRUCTURE WITH POLARIZED LIGHT EMISSION

• US 20170357127A1
• Filed: 06/08/2017
• Published: 12/14/2017
• Est. Priority Date: 06/10/2016
• Status: Active Grant

• Current Assignee: X Display Company Technology Limited (Sensinnovat BVBA)
• Original Assignee: X-Celeprint Limited
• Inventors: Cok, Ronald S., Bower, Christopher, Meitl, Matthew
• Granted Patent: US 11,137,641 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: G02F 2203/05 wavelength dependent
• CPC Class Codes: H01L 2224/24 of an individual high density interconnect connector

Abstract

A light-emitting diode (LED) structure includes an LED substrate having a first side and a second side opposing the first side. One or more light-emitting diodes are disposed on the first side and arranged to emit light through the LED substrate. In certain embodiments, a wire-grid polarizer is disposed on the second side and arranged to polarize light emitted from the one or more light-emitting diodes. A plurality of different colored LEDs or an LED with one or more color-conversion materials can be provided on the LED substrate to provide white light. A spatially distributed plurality of the LED structures can be provided in a backlight for a liquid crystal display. A polarization-preserving transmissive diffuser can diffuse light emitted from the LED toward the liquid crystal layer and a polarization-preserving reflective diffuser can diffuse light emitted from the LED away from the liquid crystal layer.

Claims

1. A light-emitting diode (LED) structure, comprising:

an LED substrate having a first side and a second side opposing the first side;

one or more light-emitting diodes (LEDs) disposed on the first side and arranged to emit light through the LED substrate; and

a wire-grid polarizer disposed on the second side and arranged to polarize light emitted from the one or more light-emitting diodes.

2. The LED structure of claim 1, wherein the LED substrate has additional sides other than the first and second sides and comprising a reflective layer disposed at least on the first side of the LED substrate around the one or more LEDs or on the additional sides of the LED substrate.

3. The LED structure of claim 1, wherein the one or more LEDs emit light of a first frequency and comprising a phosphor or one or more quantum dots disposed on, in, or over the LED substrate to convert the light emitted from the one or more LEDs to light of a second frequency lower than the first frequency.

4. The LED structure of claim 1, wherein the LED structure is a white-light-emitting LED structure.

5. The LED structure of claim 1, wherein the one or more LEDs all emit light of the same color.

6. The LED structure of claim 1, wherein the one or more LEDs at least two LEDs that emit different colors of light.

7. The LED structure of claim 1, comprising two or more electrodes electrically connected to the one or more light-emitting LEDs and two or more connection posts electrically connected to the electrodes.

8. A backlight, comprising:

a diffuser; and

one or more LED structures disposed on, over, or adjacent to the diffuser, wherein each of the one or more LED structures comprises

an LED substrate having a first side and a second side opposing the first side;

one or more light-emitting diodes (LEDs) disposed on the first side and arranged to emit light through the LED substrate; and

a wire-grid polarizer disposed on the second side and arranged to polarize light emitted from the one or more light-emitting diodes.

9. The backlight of claim 8, wherein the one or more LED structures are spatially distributed over, on, or adjacent to a common side of the diffuser.

10. The backlight of claim 8, wherein the diffuser is a polarization-preserving diffuser.

11. The backlight of claim 8, wherein the diffuser comprises metal, a metal coating, metal particles, or metal-coated particles, or is a holographic diffuser.

12. The backlight of claim 8, wherein the diffuser is a reflective diffuser.

13. The backlight of claim 8, wherein the diffuser is a transmissive diffuser.

14. The backlight of claim 8, wherein the diffuser is a spatially variable diffuser.

15. The backlight of claim 8, comprising a liquid crystal layer and a front polarizer layer, wherein the diffuser is a transmissive diffuser, and wherein the liquid crystal layer is disposed between the front polarizer layer and the transmissive diffuser and the transmissive diffuser is between the liquid crystal layer and the one or more LED structures.

16. The backlight of claim 8, comprising a liquid crystal layer and a front polarizer layer, wherein the diffuser is a reflective diffuser, and wherein the liquid crystal layer is disposed between the front polarizer layer and the one or more LED structures and the one or more LED structures are between the liquid crystal layer and the reflective diffuser.

17. The backlight of claim 8, comprising a liquid crystal layer and a front polarizer layer, and wherein the liquid crystal layer is disposed between the front polarizer layer and the one or more LED structures.

18. An LCD display, comprising:

a front polarizer layer;

a liquid crystal layer;

one or more light-emitting diode (LED) structures, each LED structure comprising;

an LED substrate having a first side and a second side opposing the first side;

one or more light-emitting diodes disposed on the first side and arranged to emit light through the LED substrate; and

a wire-grid polarizer disposed on the second side and arranged to polarize light emitted from the one or more light-emitting diodes, wherein the liquid crystal layer is disposed between the LED substrate and the front polarizer layer.

19. The LCD display of claim 18, wherein the one or more LED structures provide polarized light, there is no rear polarizer layer between the one or more LED structures and the liquid crystal layer and the front polarizer layer is the only polarizer other than the wire-grid polarizer.

20. The LCD display of claim 18, comprising a transmissive polarization-preserving diffuser disposed between the one or more LED structures and the liquid crystal layer.

21. The LCD display of claim 18, comprising a reflective polarization-preserving diffuser disposed on a side of the one or more LED structures opposite the liquid crystal layer.