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EP-4742869-A1 - LIGHT EMITTING DEVICE, DISPLAY DEVICE, PHOTOELECTRIC CONVERSION DEVICE, ELECTRONIC APPARATUS, ILLUMINATION DEVICE, MOVING BODY, AND WEARABLE DEVICE

EP4742869A1EP 4742869 A1EP4742869 A1EP 4742869A1EP-4742869-A1

Abstract

A light emitting device including first and second pixels is provided. Each of the first and second pixels includes a microlens and a light emitting element including a light emitting layer arranged between a main surface of a substrate and the microlens. A luminance distribution in a light emitting region of the light emitting layer of the first pixel and a luminance distribution in a light emitting region of the light emitting layer of the second pixel are different from each other The microlens is arranged at a position where, in a case where light enters toward the light emitting layer while passing through the microlens from a normal direction of the main surface, an area of a region where a light beam having passed through the entire microlens enters becomes larger than an area of the light emitting region.

Inventors

  • TAKAHASHI, TETSUO
  • SANO, HIROAKI
  • HINATA, SHOMA
  • SATO, RYO
  • ITO, TAKAYUKI
  • MATSUDA, YOJIRO

Assignees

  • Canon Kabushiki Kaisha

Dates

Publication Date
20260513
Application Date
20251107

Claims (20)

  1. A light emitting device including a first pixel (110a) and a second pixel (110b), wherein each of the first pixel (110a) and the second pixel (110b) includes a microlens (107) arranged above a main surface (109) of a substrate (101), and a light emitting element (120) arranged between the main surface (109) and the microlens (107), the light emitting element (120) includes a light emitting layer (131), characterized in that a luminance distribution in a light emitting region (130) of the light emitting layer (131) of the first pixel (110a) and a luminance distribution in a light emitting region (130) of the light emitting layer (131) of the second pixel (110b) are different from each other, and in each of the first pixel (110a) and the second pixel (110b), the microlens (107) is arranged at a position where, in a case where light enters toward the light emitting layer (131) while passing through the microlens (107) from a normal direction of the main surface (109), an area of an incident region (133) where a light beam having passed through the entire microlens (107) enters in a plane parallel to the main surface (109) and including an upper surface of the light emitting layer (131), becomes larger than an area of the light emitting region (130).
  2. The light emitting device according to claim 1, characterized in that in each of the first pixel and the second pixel, a whole outer edge of the light emitting region is arranged inside an outer edge of the incident region in a planar view.
  3. The light emitting device according to claim 1 or 2, characterized in that the device includes a plurality of pixels including the first pixel and the second pixel, and the first pixel and the second pixel are nearest pixels that emit light of the same color among the plurality of pixels.
  4. The light emitting device according to any one of claims 1 to 3, characterized in that in each of the first pixel and the second pixel, in a coordinate system where a direction from the first pixel to the second pixel is a first direction, a direction intersecting the first direction is a second direction, and a geometric centroid position of the light emitting region in an orthogonal projection to the main surface is an origin, a coordinate position of a first position where luminance is maximum in the light emitting region of the first pixel and a coordinate position of a second position where luminance is maximum in the light emitting region of the second pixel are different from each other.
  5. The light emitting device according to claim 4, characterized in that in the coordinate system, the first position and the second position are not less than 0.2 µm away from each other.
  6. The light emitting device according to claim 4 or 5, characterized in that in the coordinate system, the first position and the second position are not less than 0.5 µm away from each other.
  7. The light emitting device according to any one of claims 1 to 6, characterized in that a luminance at a geometric centroid position in the light emitting region of the first pixel in an orthogonal projection to the main surface and a luminance at a geometric centroid position in the light emitting region of the second pixel in an orthogonal projection to the main surface are different from each other.
  8. The light emitting device according to any one of claims 1 to 7, characterized in that a luminance at a geometric centroid position in the light emitting region of the first pixel in an orthogonal projection to the main surface and a luminance at a geometric centroid position in the light emitting region of the second pixel in an orthogonal projection to the main surface are different by not less than 2%.
  9. The light emitting device according to any one of claims 1 to 8, characterized in that a luminance at a geometric centroid position in the light emitting region of the first pixel in an orthogonal projection to the main surface and a luminance at a geometric centroid position in the light emitting region of the second pixel in an orthogonal projection to the main surface are different by not less than 5%.
  10. The light emitting device according to any one of claims 1 to 9, characterized in that a luminance at a geometric centroid position in the light emitting region of the first pixel in an orthogonal projection to the main surface and a luminance at a geometric centroid position in the light emitting region of the second pixel in an orthogonal projection to the main surface are different by not less than 10%.
  11. The light emitting device according to any one of claims 1 to 10, characterized in that in an orthogonal projection to the main surface, a light emitting region of the first pixel has a plurality of luminance peak positions.
  12. The light emitting device according to any one of claims 1 to 11, characterized in that the light emitting element includes a lower electrode arranged between the light emitting layer and the main surface, and the lower electrode includes a conductive layer and an oxide layer covering the conductive layer.
  13. The light emitting device according to any one of claims 1 to 12, characterized in that the light emitting element includes a lower electrode arranged between the light emitting layer and the main surface, and the lower electrode has an in-plane distribution of reflectance for light emitted from the light emitting region.
  14. The light emitting device according to any one of claims 1 to 13, characterized in that the light emitting element includes a lower electrode arranged between the light emitting layer and the main surface, a reflective layer arranged between the lower electrode and the main surface, and an insulating layer arranged between the lower electrode and the reflective layer.
  15. A display device characterized by comprising: the light emitting device according to any one of claims 1 to 14; and a control circuit connected to the light emitting device.
  16. A photoelectric conversion device characterized by comprising: an optical unit including a plurality of lenses; an image sensor configured to receive light having passed through the optical unit; and a display configured to display an image, wherein the display includes the light emitting device according to any one of claims 1 to 14.
  17. An electronic apparatus characterized by comprising: a housing provided with a display; and a communication unit provided in the housing and configured to perform external communication, wherein the display includes the light emitting device according to any one of claims 1 to 14.
  18. An illumination device characterized by comprising: a light source; and at least one of a light diffusing unit and an optical film, wherein the light source includes the light emitting device according to any one of claims 1 to 14.
  19. A moving body characterized by comprising: a main body; and a display provided in the main body, wherein the display includes the light emitting device according to any one of claims 1 to 14.
  20. A wearable device characterized by comprising: a display device configured to display an image, wherein the display device includes the light emitting device according to any one of claims 1 to 14.

Description

TECHNICAL FIELD The aspect of the embodiments relates to a light emitting device, a display device, a photoelectric conversion device, an electronic apparatus, an illumination device, a moving body, and a wearable device. BACKGROUND A light emitting device including a light emitting element such as an organic electroluminescence (EL) element is known. Japanese Patent Laid-Open No. 2022-080507 describes an electrooptical device that includes a microlens on a light emitting element to improve light extraction efficiency. SUMMARY If the luminance distribution in the light emitting region of the light emitting element varies among the light emitting elements, the intensity of light extracted by the microlens can vary among the light emitting elements due to the variation of the luminance distribution. The present disclosure in its first aspect provides a light emitting device as specified in claim 1. Optional features are specified in claims 2 to 14. The present disclosure in its second aspect provides a display device as specified in claim 15. The present disclosure in its third aspect provides a photoelectric conversion device as specified in claim 16. The present disclosure in its fourth aspect provides an electronic apparatus as specified in claim 17. The present disclosure in its fifth aspect provides an illumination device as specified in claim 18. The present disclosure in its sixth aspect provides a moving body as specified in claim 19. The present disclosure in its seventh aspect provides a wearable device as specified in claim 20. Features of the disclosure will become apparent from the following description of embodiments with reference to the attached drawings. The following description of embodiments is described by way of example. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view showing an example of the configuration of a light emitting device according to an embodiment;Fig. 2 is a view for explaining light emitted from a pixel of the light emitting device shown in Fig. 1;Fig. 3 is a view for explaining light entering the pixel of the light emitting device shown in Fig. 1;Fig. 4 is a view showing an example of the optical path of light passing through a microlens of the light emitting device shown in Fig. 1;Fig. 5 is a view showing an example of the optical path of light passing through a microlens of the light emitting device shown in Fig. 1;Figs. 6A and 6B are views for explaining the light emitting device of a comparative example;Figs. 7A and 7B are views for explaining the effect of the light emitting device shown in Fig. 1;Fig. 8 is a view for explaining evaluation of the distribution of light emission intensity of the light emitting device shown in Fig. 1;Fig. 9 is a view showing an example of the optical path of light passing through a microlens of the light emitting device shown in Fig. 1;Figs. 10A and 10B are an orthogonal projection view and a sectional view showing a modification of the light emitting device shown in Fig. 1;Fig. 11 is a sectional view showing a modification of the light emitting device shown in Fig. 1;Figs. 12A and 12B are sectional views showing an example of the configuration of a pixel of the light emitting device according to the embodiment;Figs. 13A to 13C are views showing an example of an image forming apparatus using the light emitting device according to the embodiment;Fig. 14 is a view showing an example of a display device using the light emitting device according to the embodiment;Fig. 15 is a view showing an example of a photoelectric conversion device using the light emitting device according to the embodiment;Fig. 16 is a view showing an example of an electronic apparatus using the light emitting device according to the embodiment;Figs. 17A and 17B are views each showing an example of a display device using the light emitting device according to the embodiment;Fig. 18 is a view showing an example of an illumination device using the light emitting device according to the embodiment;Figs. 19A and 19B are views showing an example of a moving body using the light emitting device according to the embodiment; andFigs. 20A and 20B are views each showing an example of a wearable device using the light emitting device according to the embodiment. DESCRIPTION OF THE EMBODIMENTS Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claims. Multiple features are described in the embodiments, but it is not the case that all such features are required, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. With reference to Figs. 1 to 11, a light emitting device according to an embodiment of the disclosure will be described. Fig. 1 is a sectional view showing an example of the con