Image display device
An image display device includes a drive circuit substrate, micro LED elements, and a wavelength conversion layer that converts excitation light emitted from the micro LED elements and that emits converted long-wavelength light to a side opposite to the drive circuit substrate, the micro LED elements and the wavelength conversion layer being sequentially stacked on the drive circuit substrate. The micro LED elements include a first multilayer film that reflects the long-wavelength light converted by the wavelength conversion layer.
1. An image display device comprising:
a drive circuit substrate;
micro LED elements;
a red wavelength conversion layer and a green wavelength conversion layer that each convert excitation light emitted from a corresponding one of the micro LED elements and emit converted red light and converted green light, respectively, to a side opposite to the drive circuit substrate, each of the micro LED elements and a corresponding either of the red wavelength conversion layer or the green wavelength conversion layer being stacked in this order on the drive circuit substrate,
wherein each of the micro LED elements includes a first multilayer film that reflects the red light and the green light converted by the red wavelength conversion layer and the green wavelength conversion layer, respectively, where the first multilayer film is only placed on a side of the micro LED element faced to the drive circuit substrate; and
a second multilayer film that transmits both the red light and the green light and reflects the excitation light, the second multilayer film being disposed on an emission side of the red wavelength conversion layer and an emission side of the green wavelength conversion layer.
2. The image display device according to claim 1 ,
wherein the first multilayer film of the micro LED element is separated from each other.
3. The image display device according to claim 1 ,
wherein the first multilayer film is included inside a nitride semiconductor layer that forms the micro LED elements.
4. The image display device according to claim 1 ,
wherein the first multilayer film is disposed on the wavelength conversion layer side with respect to a light emission layer of the micro LED elements and transmits the excitation light.
5. The image display device according to claim 1 ,
wherein the first multilayer film reflects the excitation light.
6. The image display device according to claim 1 ,
wherein the first multilayer film includes a nitride semiconductor.
7. The image display device according to claim 6 ,
wherein the first multilayer film has conductivity.
8. The image display device according to claim 7 ,
wherein the first multilayer film has N-type conductivity.
9. The image display device according to claim 7 ,
wherein the first multilayer film has P-type conductivity.
10. The image display device according to claim 6 ,
wherein the first multilayer film has high resistivity.
11. The image display device according to claim 1 ,
wherein the first multilayer film is a dielectric multilayer film.
12. The image display device according to claim 11 ,
wherein the first multilayer film has a through portion in part thereof, and the through portion is provided for each of the micro LED elements.
13. The image display device according to claim 12 ,
wherein the through portion is filled with a nitride semiconductor.
14. The image display device according to claim 12 ,
wherein the through portion is filled with an electrode material.
15. The image display device according to claim 1 , comprising:
a filter layer that transmits the long-wavelength light and that absorbs the excitation light, the filter layer being disposed on an emission side of the wavelength conversion layer.
16. The image display device according to claim 1 , comprising:
a color filter layer that absorbs the excitation light and that transmits part of the long-wavelength light, the color filter layer being disposed on an emission side of the wavelength conversion layer.
17. The image display device according to claim 15 ,
wherein the first multilayer film has peak reflectances at a wavelength of 460±15 nm, a wavelength of 520±15 nm, and a wavelength of 630±15 nm, and
the second multilayer film has a peak reflectance at a wavelength of 460±15 nm.
18. The image display device according to claim 1 ,
wherein the red wavelength conversion layer and the green wavelength conversion layer include both wavelength conversion particles and scattering particles that do not perform wavelength conversion.
19. The image display device according to claim 1 ,
wherein the micro LED elements includes a layered structure that includes a transparent insulating film and a metal film having a high reflectance on all sidewalls of the micro LED element, where the sidewalls are surfaces of the micro LED element other than the emission side surface and the drive circuit substrate side surface.
20. The image display device according to claim 1 ,
wherein the second multilayer film is covered with a passivation film.
21. The image display device according to claim 1 ,
wherein a transparent resin layer is provided between the second multilayer film and the red and green wavelength conversion layers and the red and green wavelength conversion layers, the transparent resin layer, and the second multilayer film are stacked in this order.
22. The image display device according to claim 1 ,
wherein the red wavelength conversion layer and the green wavelength conversion layer cover a whole of light emission surfaces of the micro LED elements.
23. An image display device comprising:
a drive circuit substrate;
micro LED elements; and
a wavelength conversion layer that converts excitation light emitted from the micro LED elements and that emits converted long-wavelength light to a side opposite to the drive circuit substrate, the micro LED elements and the wavelength conversion layer being sequentially stacked on the drive circuit substrate,
wherein each of the micro LED elements includes a first multilayer film that reflects the long-wavelength light converted by the wavelength conversion layer, where the first multilayer film is only placed on a side of the micro LED element faced to the drive circuit substrate, and
the wavelength conversion layers covers a whole light emission surfaces of the micro LED elements.
24. The image display device according to claim 23 ,
wherein a side edge of the first multilayer film is aligned with a side edge of a nitride semiconductor layer of the micro LED elements.
25. The image display device according to claim 23 ,
wherein the micro LED elements include a layered structure that includes a transparent insulating film and a metal film having a high reflectance on all sidewalls of the micro LED element, where the sidewalls are surfaces of the micro LED element other than the emission side surface and the drive circuit substrate side surface.
26. The image display device according to claim 23 , comprising:
a second multilayer film that transmits the long-wavelength light and that reflects the excitation light, the second multilayer film being disposed on an emission side of the wavelength conversion layer.
27. The image display device according to claim 26 ,
wherein the second multilayer film is covered with a passivation film.
28. The image display device according to claim 26 ,
wherein a transparent resin layer is provided between the second multilayer film and the wavelength conversion layers and the red and green wavelength conversion layers, the transparent resin layer, and the second multilayer film are stacked in this order.
29. The image display device according to claim 23 ,
wherein the wavelength conversion layers includes both wavelength conversion particles and scattering particles.
30. An image display device comprising:
a drive circuit substrate;
micro LED elements; and
a wavelength conversion layer that converts excitation light emitted from the micro LED elements and that emits converted long-wavelength light to a side opposite to the drive circuit substrate, the micro LED elements and the wavelength conversion layer being sequentially stacked on the drive circuit substrate,
wherein each of the micro LED elements includes a first multilayer film that reflects the long-wavelength light converted by the wavelength conversion layer,
the first multilayer film is only placed on a side of the micro LED element faced to the drive circuit substrate, and
a side edge of the first multilayer film is aligned with a side edge of a nitride semiconductor layer of the micro LED elements.
31. The image display device according to claim 30 ,
wherein the micro LED elements include a layered structure that includes a transparent insulating film and a metal film having a high reflectance on all sidewalls of the micro LED element, where the sidewalls are surfaces of the micro LED element other than the emission side surface and the drive circuit substrate side surface.
32. The image display device according to claim 30 ,
wherein the wavelength conversion layers includes both wavelength conversion particles and scattering particles that do not perform wavelength conversion.
33. The image display device according to claim 1 ,
wherein each of the micro LED elements includes a transparent electrode layer between a nitride semiconductor layer of the micro LED element and the first multilayer film.
34. The image display device according to claim 23 ,
wherein each of the micro LED elements includes a transparent electrode layer between a nitride semiconductor layer of the micro LED element and the first multilayer film.
35. The image display device according to claim 30 ,
wherein each of the micro LED elements includes a transparent electrode layer between a nitride semiconductor layer of the micro LED element and the first multilayer film.