JP2019192888A - Light-emitting device and projector - Google Patents

Abstract

To provide an optical device that can efficiently illuminate an object to be illuminated.SOLUTION: A light-emitting device 100 comprises a plurality of light-emitting units 2 having a light-emitting element 20 and a lens 50 provided corresponding to the light-emitting element 20. The light-emitting element 20 has a luminescent layer 24 that is provided between a first semiconductor layer 22 and a second semiconductor layer 26 and can generate light upon injection of current, a first electrode 30 that is electrically connected to the first semiconductor layer 22; and a second electrode 32 that is in contact with the second semiconductor layer 26. In plan view viewed from a lamination direction of the first semiconductor layer 22 and luminescent layer 24, the second electrode 32 overlaps the luminescent layer 24; in plan view viewed from the lamination direction, the plurality of light-emitting units 2 are arranged at a pitch p in a first direction; the size d in the first direction of a contact area of the second semiconductor layer 26 and second electrode 32 and the pitch p satisfy the relationships of d/p≤0.5, d≥2 μm, and p≤12 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device and a projector.

  Mercury lamps, which have been widely used as light sources for projectors, have a life problem that they gradually become darker and suddenly cut off, and there is a problem with mercury regulation. ing.

  For example, in Patent Document 1, 300 (15 × 20) LED lamps having a plurality of LED chips are arranged two-dimensionally on an LED substrate with an arrangement pitch of 4 mm, and the output light of the LED lamp is parallelized by a microlens array. A light projector is described.

JP 2006-317935 A

  The light source (light emitting device) of the projector as described above is desired to efficiently illuminate an illumination target such as a screen.

One aspect of the light emitting device according to the present invention is:
A plurality of light emitting units having a light emitting element and a lens provided corresponding to the light emitting element;
The light emitting element is
A first semiconductor layer;
A second semiconductor layer having a conductivity type different from that of the first semiconductor layer;
A light emitting layer provided between the first semiconductor layer and the second semiconductor layer and capable of generating light by injecting a current;
A first electrode electrically connected to the first semiconductor layer;
A second electrode in contact with the second semiconductor layer;
Have
In a plan view seen from the stacking direction of the first semiconductor layer and the light emitting layer, the second electrode overlaps the light emitting layer,
In a plan view seen from the stacking direction, the plurality of light emitting units are arranged at a pitch p in the first direction,
The size d in the first direction of the contact region between the second semiconductor layer and the second electrode, and the pitch p are:
d / p ≦ 0.5, d ≧ 2 μm, and p ≦ 12 μm
Satisfy the relationship.

In one aspect of the light emitting device,
The size d and the pitch p are:
0.4 ≦ d / p ≦ 0.5
May be satisfied.

In one aspect of the light emitting device,
The size d and the pitch p are:
d / p ≦ 0.3
May be satisfied.

In one aspect of the light emitting device,
The first light emitting element among the plurality of light emitting elements is adjacent to the second light emitting element among the plurality of light emitting elements,
The light emitted from the first light emitting element may not be totally reflected by the lens provided corresponding to the second light emitting element among the plurality of lenses.

In one aspect of the light emitting device,
One aspect of the projector according to the present invention is as follows:
An aspect of the light emitting device;
A projection device for projecting light emitted from the light emitting device;
Have

Sectional drawing which shows typically the light-emitting device which concerns on 1st Embodiment. The top view which shows typically the light-emitting device which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the light-emitting device which concerns on 1st Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on 2nd Embodiment. The top view which shows typically the light-emitting device which concerns on 2nd Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on 3rd Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on a reference example. Sectional drawing which shows typically the light-emitting device which concerns on 3rd Embodiment. The graph which shows the minimum value of the curvature radius of a lens. The graph which shows the minimum value of the curvature radius of a lens. The graph which shows projection efficiency. The graph which shows projection efficiency. The graph which shows projection efficiency. Sectional drawing which shows typically the light-emitting device which concerns on the modification of 3rd Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on a reference example. Sectional drawing which shows typically the light-emitting device which concerns on the modification of 3rd Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on the modification of 3rd Embodiment. Sectional drawing which shows typically the light-emitting device which concerns on the modification of 3rd Embodiment. FIG. 10 is a diagram schematically illustrating a projector according to a fourth embodiment. The figure which shows typically the projector which concerns on the 1st modification of 4th Embodiment. The figure which shows typically the projector which concerns on the 2nd modification of 4th Embodiment. The graph which shows the relationship between the magnitude | size of a contact area | region, and projection efficiency. The graph which shows the relationship between the magnitude | size of a contact area, and a projection light beam. The graph which shows the relationship between an electric current density and optical power density. The graph which shows the relationship between the magnitude | size of a contact area | region, and a current density and total electric current amount. The graph which shows the relationship between the magnitude | size of a contact area, and a projection light beam. The graph which shows the relationship between the magnitude | size of a contact area, and efficiency. The graph which shows the relationship between the ratio of the magnitude | size of the contact area with respect to a pitch, and a projection light beam. The graph which shows the relationship between the ratio of the size of the contact area to the pitch, and the efficiency.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. 1. First embodiment 1.1. First, the light emitting device according to the first embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a light emitting device 100 according to the first embodiment. FIG. 2 is a plan view schematically showing the light emitting device 100 according to the first embodiment. 1 is a cross-sectional view taken along the line II of FIG. 1 and 2 illustrate the X axis, the Y axis, and the Z axis as three axes orthogonal to each other.

  As illustrated in FIGS. 1 and 2, the light emitting device 100 includes, for example, a substrate 10, a light emitting element 20, an insulating layer 40, and a lens 50. For convenience, the second electrode 32 and the insulating layer 40 of the light emitting element 20 are not shown in FIG.

  The substrate 10 is, for example, a sapphire substrate. For example, the substrate 10 can transmit light generated in the light emitting layer 24 of the light emitting element 20.

  The light emitting element 20 is provided on the substrate 10. A plurality of light emitting elements 20 are provided. As shown in FIG. 2, the plurality of light emitting elements 20 are in a plan view as viewed from the stacking direction (Z-axis direction in the illustrated example) of the first semiconductor layer 22 and the light emitting layer 24 of the light emitting element 20 (hereinafter simply “ In a plan view, it is also provided in a matrix. The plurality of light emitting elements 20 are arranged at a pitch p in the first direction (for example, the X-axis direction) and in the second direction (for example, the Y-axis direction) orthogonal to the first direction. The number of light-emitting elements 20 is not particularly limited, but is, for example, about 10,000 (100 × 100 in the X-axis direction and 100 in the Y-axis direction). The light emitting element 20 is, for example, an LED. In the illustrated example, the plurality of light emitting elements 20 are arranged in a square arrangement with a pitch p in the first direction and the second direction orthogonal to the first direction. It may be a hexagonal arrangement arranged at a pitch p in the direction and the second direction inclined by 60 ° C. with respect to the first direction.

  In the present invention, “up” refers to a direction away from the substrate 10 when viewed from the light emitting layer 24 of the light emitting element 20 in the stacking direction of the first semiconductor layer 22 and the light emitting layer 24 of the light emitting element 20. “Lower” means a direction approaching the substrate 10 when viewed from the light emitting layer 24 in the stacking direction. In the illustrated example, “upper” is the + Z-axis direction side, and “lower” is the −Z-axis direction side.

  As illustrated in FIG. 1, the light emitting element 20 includes, for example, a first semiconductor layer 22, a light emitting layer 24, a second semiconductor layer 26, a first electrode 30, and a second electrode 32. .

  The first semiconductor layer 22 is provided on the substrate 10. The first semiconductor layer 22 is provided between the substrate 10 and the light emitting layer 24. The thickness of the first semiconductor layer 22 is, for example, about 5 μm. The first semiconductor layer 22 is, for example, an n-type GaN layer doped with Si. In the illustrated example, in the adjacent light emitting elements 20, the first semiconductor layer 22 is continuous, and in the plurality of light emitting elements 20, the first semiconductor layer 22 is one common layer.

  A part of the first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26 constitute, for example, a columnar portion 28. In the plurality of light emitting elements 20, the columnar portions 28 are provided separately from each other. In the example shown in FIG. 2, the columnar portion 28 has a square shape in plan view.

  As shown in FIG. 1, the light emitting layer 24 is provided on the first semiconductor layer 22. The light emitting layer 24 is provided between the first semiconductor layer 22 and the second semiconductor layer 26. The light emitting layer 24 has, for example, a multiple quantum well (MQW) structure in which five pairs of InGaN layers having a thickness of about 2.5 nm and GaN layers having a thickness of about 12 nm are alternately stacked. The light emitting layer 24 is a layer capable of generating light when current is injected.

  The second semiconductor layer 26 is provided on the light emitting layer 24. The thickness of the second semiconductor layer 26 is, for example, about 150 nm. The second semiconductor layer 26 is a layer having a different conductivity type from the first semiconductor layer 22. The second semiconductor layer 26 is, for example, a p-type GaN layer doped with Mg.

  In the light emitting device 100, the p-type second semiconductor layer 26, the light emitting layer 24 not doped with impurities, and the n-type first semiconductor layer 22 constitute a pin diode. The semiconductor layers 22 and 26 are layers having a larger band gap than the light emitting layer 24. In the light emitting device 100, when a forward bias voltage of a pin diode is applied between the first electrode 30 and the second electrode 32 (current is injected), recombination of electrons and holes occurs in the light emitting layer 24. This recombination causes light emission.

  Light generated in the light emitting layer 24 (light traveling toward the −Z axis direction) is transmitted through the substrate 10 and emitted. The light generated in the light emitting layer 24 (light directed toward the + Z axis direction) is reflected by the second electrode 32, for example. In FIG. 1, light (light rays) generated in the light emitting layer 24 and transmitted through the substrate 10 is indicated by arrows.

  The first electrode 30 is provided on the first semiconductor layer 22. In the illustrated example, the first electrode 30 is in contact with the first semiconductor layer 22. The first electrode 30 may be in ohmic contact with the first semiconductor layer 22. The first electrode 30 is electrically connected to the first semiconductor layer 22.

  The first electrode 30 is one electrode for injecting current into the light emitting layer 24. As the first electrode 30, for example, an electrode in which a Ti layer and an Al layer are stacked in this order from the first semiconductor layer 22 side is used. In the example shown in FIG. 2, in the adjacent light emitting elements 20, the first electrodes 30 are continuous, and in the plurality of light emitting elements 20, the first electrodes 30 are provided in a grid pattern as one common electrode. Yes. The first electrode 30 is provided so as to be separated from the columnar portion 28 and surround the columnar portion 28.

  As shown in FIG. 1, the second electrode 32 is provided on the second semiconductor layer 26. The second electrode 32 is in contact with the second semiconductor layer 26. The second electrode 32 may be in ohmic contact with the second semiconductor layer 26. The second electrode 32 overlaps the light emitting layer 24 in plan view. The second electrode 32 is electrically connected to the second semiconductor layer 26. In the illustrated example, the second electrode 32 is also provided on the insulating layer 40.

  The second electrode 32 is the other electrode for injecting current into the light emitting layer 24. The material of the second electrode 32 is a conductor having a high reflectance with respect to light generated in the light emitting layer 24, such as an APC alloy that is an alloy of Ag, Pd, and Cu. In the illustrated example, in the adjacent light emitting elements 20, the second electrode 32 is continuous, and in the plurality of light emitting elements 20, the second electrode 32 is one common electrode.

The contact area 34 between the second electrode 32 and the second semiconductor layer 26 is a square as shown in FIG. The contact region 34 is a contact surface between the second electrode 32 and the second semiconductor layer 26. The plurality of contact regions 34 are provided in a matrix shape in plan view. The plurality of contact areas 34 are
For example, they are arranged at a pitch p in the X-axis direction and the Y-axis direction.

As shown in FIG. 1, the insulating layer 40 is provided on the first semiconductor layer 22 and the first electrode 30 around the columnar portion 28. The insulating layer 40 electrically separates the first electrode 30 and the second electrode 32. The insulating layer 40 is, for example, a silicon oxide layer (for example, a SiO ₂ layer).

  The lens 50 is provided under the substrate 10. The lens 50 is bonded to the lower surface of the substrate 10, for example. In the illustrated example, the lens 50 is a convex lens in which the incident surface 51a on the substrate 10 side is a flat surface and the exit surface 51b on the opposite side to the substrate 10 is a curved surface. A plurality of lenses 50 are provided. The plurality of lenses 50 constitute a lens array 52. The lens array 52 is, for example, a microlens array (MLA).

  The lens 50 is provided corresponding to the light emitting element 20. That is, light emitted from one light emitting element 20 enters one lens 50. In the illustrated example, the columnar portion 28 of one light emitting element 20 is disposed inside the outer edge of one lens 50 as viewed from the Z-axis direction. The material of the lens 50 is, for example, glass. The lens 50 can narrow the emission angle of the light emitted from the light emitting element 20 to Lambertian.

  The center position of the lens 50 is the same as, for example, the center position of the contact area 34 in plan view. The plurality of lenses 50 are provided in a matrix in a plan view. The plurality of lenses 50 are arranged at a pitch p in the X-axis direction and the Y-axis direction, for example, in plan view.

  The light emitting element 20 and the lens 50 constitute a plurality of light emitting units 2. That is, the light emitting device 100 includes a plurality of light emitting units 2 including the light emitting element 20 and the lens 50 provided corresponding to the light emitting element 20. The plurality of light emitting units 2 are arranged at a pitch p in the X-axis direction and the Y-axis direction, for example, in plan view.

  The size d in the X-axis direction of the contact region 34 between the second semiconductor layer 26 and the second electrode 32 and the pitch p in the X-axis direction of the light emitting unit 2 are expressed by the following equations (1), (2), (3). Satisfy the relationship.

d / p ≦ 0.5 (1)
d ≧ 2 μm (2)
p ≦ 12μm (3)

  From equations (1), (2), and (3), the size d is 2 μm or more and 6 μm or less, and the pitch p is 4 μm or more and 12 μm or less.

  The size d and the pitch p may satisfy the following formula (4), or may satisfy the following formula (5).

0.4 ≦ d / p ≦ 0.5 (4)
d / p ≦ 0.3 (5)

  For example, the light emitting device 100 has the following characteristics.

In the light emitting device 100, the size d in the X axis direction of the contact region 34 between the second semiconductor layer 26 and the second electrode 32 and the pitch p in the X axis direction of the light emitting unit 2 are d / p ≦ 0.5, The relationship d ≧ 2 μm and p ≦ 12 μm is satisfied. Therefore, the light emitting device 100 can efficiently illuminate an illumination target such as a screen as compared with a light emitting device outside the above range (see “Experimental Example” described later for details). As a result, in the light emitting device 100, power saving can be achieved.

  In the light emitting device 100, the size d and the pitch p may satisfy a relationship of 0.4 ≦ d / p ≦ 0.5. Such a light emitting device 100 can achieve higher luminance than a light emitting device outside the above range (see “Experimental examples” described later for details).

  In the light emitting device 100, the size d and the pitch p may satisfy the relationship d / p ≦ 0.3. In such a light-emitting device 100, it is possible to illuminate an illumination target more efficiently than a light-emitting device outside the above range (for details, refer to “Experimental Example” described later).

  In the above description, the GaN-based light-emitting element 20 that emits blue light has been described. However, by using a semiconductor layer such as a GaP-based or GaAs-based material, the light-emitting element can emit green light or red light. .

  In the above description, the first semiconductor layer 22 is an n-type semiconductor layer and the second semiconductor layer 26 is a p-type semiconductor layer. However, the first semiconductor layer 22 is a p-type semiconductor layer. In addition, the second semiconductor layer 26 may be an n-type semiconductor layer.

  Further, although not shown, a heat sink may be provided on the + Z axis direction side of the second electrode 32. The heat sink may be bonded to the second electrode 32. The material of the heat sink is copper, aluminum or the like. The heat sink can efficiently dissipate heat generated in the light emitting element 20.

1.2. Method for Manufacturing Light-Emitting Device Next, a method for manufacturing the light-emitting device 100 according to the first embodiment will be described with reference to the drawings. FIG. 3 is a cross-sectional view schematically showing the manufacturing process of the light emitting device 100 according to the first embodiment.

  As shown in FIG. 3, the first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26 are epitaxially grown in this order on the substrate 10. Examples of the epitaxial growth method include MOCVD (Metal Organic Chemical Vapor Deposition) method, MBE (Molecular Beam Epitaxy) method, and the like.

  As shown in FIG. 1, the second semiconductor layer 26, the light emitting layer 24, and the first semiconductor layer 22 are patterned to form columnar portions 28. The patterning is performed by, for example, photolithography and etching.

  Next, the first electrode 30 is formed on the first semiconductor layer 22. The first electrode 30 is formed by, for example, a vacuum evaporation method.

  Next, the insulating layer 40 is formed on the semiconductor layers 22 and 26 and the first electrode 30. The insulating layer 40 is formed by, for example, a spin coating method, a CVD (Chemical Vapor Deposition) method, or the like. Next, the insulating layer 40 is patterned to expose the second semiconductor layer 26.

  Next, the second electrode 32 is formed on the second semiconductor layer 26 and the insulating layer 40. The second electrode 32 is formed by, for example, a vacuum evaporation method.

  Next, the lens array 52 is bonded to the lower surface of the substrate 10 with an adhesive, for example.

  Through the above steps, the light emitting device 100 can be manufactured.

  In the above description, an example in which the semiconductor layers 22 and 26 and the light emitting layer 24 are epitaxially grown and then the semiconductor layers 22 and 26 and the light emitting layer 24 are patterned to form the columnar portion 28 has been described. (Not shown) may be formed, and then the columnar portion 28 may be formed by epitaxially growing the semiconductor layers 22 and 26 and the light emitting layer 24 using the mask layer as a mask.

2. Second Embodiment 2.1. Next, a light emitting device according to a second embodiment will be described with reference to the drawings. FIG. 4 is a cross-sectional view schematically showing the light emitting device 200 according to the second embodiment. FIG. 5 is a plan view schematically showing the light emitting device 200 according to the second embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. 4 and 5 illustrate the X axis, the Y axis, and the Z axis as three axes orthogonal to each other.

  Hereinafter, the light emitting device 200 according to the second embodiment will be described with respect to differences from the above-described example of the light emitting device 100 according to the first embodiment, and description of similar points will be omitted.

  As shown in FIG. 4, the light emitting device 200 is different from the above-described light emitting device 100 in that a drive circuit substrate 64 is provided between the substrate 60 and the light emitting element 20. 4 and 5, the light emitting device 200 includes, for example, a substrate 60, a heat sink 62, a drive circuit substrate 64, an insulating layer 70, a first through via 80, a second through via 82, A pad 84 and a wiring 86 are provided.

  In the light emitting device 200, the substrate 60 is, for example, a silicon substrate.

  The heat sink 62 is provided under the substrate 60. The heat sink 62 is bonded to the lower surface of the substrate 60, for example. The material of the heat sink 62 is copper, aluminum, or the like. The heat sink 62 can efficiently dissipate heat generated in the light emitting element 20.

  The drive circuit board 64 is provided on the board 60. A drive circuit for driving the light emitting element 20 is mounted on the drive circuit board 64. The drive circuit is realized by, for example, a CMOS (Complementary Metal Oxide Semiconductor). For example, the drive circuit can drive the light emitting element 20 based on the input image information. Therefore, one light emitting element 20 can form one pixel. The light emitting device 200 is, for example, a self light emitting imager.

  The insulating layer 70 is provided on the drive circuit board 64. The insulating layer 70 is, for example, a silicon oxide layer.

  The first through via 80 and the second through via 82 are provided through the insulating layer 70. The material of the through vias 80 and 82 is, for example, Ti. The first through via 80 connects the drive circuit mounted on the drive circuit board 64 and the second electrode 32 of the light emitting element 20. The second through via 82 connects the drive circuit and the pad 84.

  The pad 84 is provided on the second through via 82. The material of the pad 84 is metal, for example.

  The wiring 86 connects the pad 84 and the first electrode 30 of the light emitting element 20. The material of the wiring 86 is, for example, metal.

  The light emitting element 20 is provided on the first through via 80 and the insulating layer 70. The plurality of light emitting elements 20 are separated from each other. In the illustrated example, the second electrode 32, the second semiconductor layer 26, the light emitting layer 24, the first semiconductor layer 22, and the first electrode 30 are provided side by side from the first through via 80 side in this order. The semiconductor layers 22 and 26, the light emitting layer 24, and the electrodes 30 and 32 have, for example, the same shape (square in the example shown in FIG. 5) in plan view.

  The first electrode 30 is electrically connected to the drive circuit via the wiring 86, the pad 84, and the second through via 82. The material of the first electrode 30 is a transparent electrode such as ITO (Indium Tin Oxide). The light generated in the light emitting layer 24 passes through the first electrode 30 and enters the lens 50.

  The second electrode 32 is electrically connected to the drive circuit via the first through via 80. For the second electrode 32, an Al layer and a Ti layer stacked in this order from the second semiconductor layer 26 side are used. By sufficiently smoothing and cleaning Ti of the second electrode 32 and Ti of the first through via 80 and pressurizing and heating, the second electrode 32 and the first through via 80 can be metal-bonded. it can.

  In the light emitting device 200, the first electrode 30 and the second electrode 32 overlap the light emitting layer 24 in a plan view. In such a case, the second semiconductor layer 26 forming the contact region 34 is a semiconductor layer having a smaller area of the contact region between the n-type semiconductor layer and the p-type semiconductor layer. In the case where the contact areas have the same area, any one of the semiconductor layers is formed. In the illustrated example, the second semiconductor layer 26 is a p-type semiconductor layer, and the area of the contact region 34 between the second semiconductor layer 26 and the second electrode 32 is equal to the first semiconductor layer 22, the first electrode 30, and the like. It is the same as the area of the contact region.

  In the light emitting device 200, the lens array 52 is provided on the + Z axis direction side of the light emitting element 20. The lens array 52 is bonded to a support member (not shown), for example.

2.2. Method for Manufacturing Light Emitting Device Next, a method for manufacturing the light emitting device 200 according to the second embodiment will be described with reference to the drawings.

  Hereinafter, in the method for manufacturing the light emitting device 200 according to the second embodiment, differences from the example of the method for manufacturing the light emitting device 100 according to the first embodiment described above will be described, and description of similar points will be omitted or simplified. .

  As shown in FIG. 3, the first semiconductor layer 22, the light emitting layer 24, and the second semiconductor layer 26 are epitaxially grown in this order on the substrate 10.

  Next, the substrate 10 is removed by polishing and plasma etching. Next, as shown in FIG. 4, the first electrode 30 and the second electrode 32 are formed. Through the above steps, the light-emitting element 20 can be formed. Note that the second electrode 32 may be formed before the substrate 10 is removed.

Next, the substrate 60, the heat sink 62, the drive circuit substrate 64, the insulating layer 70, and the through vias 80 and 82 are prepared, the second electrode 32 side is directed to the first through via 80, and the light emitting element 20 is secondly arranged.
The through via 82 is connected.

  Next, the pad 84 is formed on the second through via 82. The pad 84 is formed by, for example, a sputtering method or a plating method. The pad 84 may be formed before connecting the light emitting element 20 to the first through via 80.

  Next, the insulating layer 40 is formed on the first electrode 30 and the pad 84. Next, the insulating layer 40 is patterned to expose the first electrode 30 and the pad 84.

  Next, a wiring 86 is formed on the first electrode 30 and the pad 84. The wiring 86 is formed by, for example, a sputtering method or a plating method.

  Next, the lens array 52 is disposed. The heat sink 62 may be adhered to the back surface of the substrate 60 after the lens array 52 is disposed.

  The light emitting device 200 can be manufactured through the above steps.

3. Third Embodiment 3.1. Light Emitting Device Next, a light emitting device according to a third embodiment will be described with reference to the drawings. FIG. 6 is a cross-sectional view schematically showing a light emitting device 300 according to the third embodiment. For convenience, illustration of members other than the light emitting element 20, the lens array 52, and the substrate 60 is omitted in FIG. In FIG. 6, the light emitting element 20 is illustrated in a simplified manner. 6 and FIGS. 7 and 8 to be described later, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other.

  Hereinafter, in the light emitting device 300 according to the third embodiment, points that differ from the example of the light emitting device 200 according to the second embodiment described above will be described, and description of similar points will be omitted.

  In the light emitting device 300, as shown in FIG. 6, the shape of the lens 50 is different from that of the light emitting device 100 described above.

  In the light emitting device 300, the light emitting element 20 is provided on the substrate 60. Among the plurality of light emitting elements 20, the first light emitting element 20 a is adjacent to the second light emitting element 20 b among the plurality of light emitting elements 20. Among the plurality of lenses 50, the first lens 50a is a lens provided corresponding to the first light emitting element 20a. Among the plurality of lenses 50, the second lens 50b is a lens provided corresponding to the second light emitting element 20b. The first lens 50a is adjacent to the second lens 50b. The light emitted from the first light emitting element 20a is not totally reflected by the first lens 50a and the second lens 50b.

  For example, in the example shown in FIG. 7, the light ray L1 is a light ray that travels with the radiation angle narrowed in the direction of the illumination target (target direction), and is projected onto the screen by the projection lens. The light beam L2 is a light beam that spreads in a direction different from the target direction and does not squeeze into the projection lens, and therefore does not affect the projection display. The light beam L <b> 3 is a light beam that repeats total reflection in the lens array 52. A part of the light beam L3 is scattered by the concavo-convex structure formed by the light emitting element 20 or the like, resulting in crosstalk that blurs brightly a position unrelated to display.

  In the light emitting device 300 illustrated in FIG. 6, the above-described crosstalk can be reduced. FIG. 7 is a cross-sectional view schematically showing a light emitting device according to a reference example.

Here, FIG. 8 is an enlarged view of FIG. When the refractive index between the lens array 52 and the substrate 60 is n ₁ , the refractive index of the lens array 52 is n ₂ , and the refractive index on the outside (+ Z-axis direction side) of the lens array 52 is n ₃ , n ₁ <n _2> is _{n 3.} When the magnitude relationship between n ₁ and n ₂ is reversed (when n ₁ > n ₂ ), part of the light emitted from the light emitting element 20 is totally reflected at the interface (incident surface 51a) between n ₁ and n _2. Thus, n ₁ <n ₂ because crosstalk occurs. Air may be between the lens array 52 and the substrate 60 and outside the lens array 52.

The second lens 50b is divided into a region A and a region B with a point C that is the vertex of the emission surface 51b as a boundary. At point C, the exit surface 51b and the entrance surface 51a of the second lens 50b are parallel to each other, so that the light passing through the point C cannot be bent in the traveling direction by the second lens 50b. On the other hand, light passing through the region A is bent in a narrowing direction, and light passing through the region B is bent in a spreading direction. Here, the problem is the light passing through the region B that may be totally reflected. In particular, the point D (the boundary between the first lens 50a and second lens 50b), in a typical radius of curvature R, the incidence angle theta ₃ of light is that the highest increase. If it is not totally reflected at the point D, it is not totally reflected in the entire region B.

The conditions for not totally reflecting at the point D are as follows. Assuming that the inclination angle of the second lens 50b at the point D is α and the incident angles of light from the most light emitting element 20a to the point D from the + X-axis direction side are θ ₁ and θ ₂ , Since it is (6), the following formula (7) can be derived.

The condition that the total reflection does not occur at the point D is represented by the following formula (8) according to Snell's law. Since θ ₃ = θ ₂ + α, the following formula (9) can be derived. Then, the following equation (10) can be derived from the equations (6) and (9).

If α is set so as to satisfy Expression (10), total reflection does not occur in the entire region B. Θ ₁ is the distance d ₁ between the light emitting element 20 and the lens array 52, the thickness d ₂ of the lens array 52, the pitch (pitch of the light emitting unit 2) p of the light emitting element 20 and the lens 50, and the light emitting element. It depends on the size of 20 in plan view.

In equation (10), the maximum value α _MAX of α was determined while changing d ₁ and d ₂ , and the minimum value R _MIN of the radius of curvature R was determined from the following equation (11).

9 and 10 are graphs showing the relationship between the distances d ₁ and d ₂ and the minimum value R _{MIN of the} radius of curvature R. 9 and 10, n ₁ = 1 (air) and n ₃ = 1 (air). In FIG. 9, n ₂ = 1.68 (high refractive index glass), and in FIG. 10, n ₂ = 1.46 (quartz glass). In FIGS. 9 and 10, p = 10 μm, and the LED size (size in plan view) is 4 μm square.

9 and 10, in the region H, R _MIN is not less than 5 μm and less than 10 μm. In the region I, R _MIN is not less than 10 μm and less than 15 μm. In the region J, R _MIN is not less than 15 μm and less than 20 μm. In the region K, R _MIN is 20 μm or more and less than 25 μm. In the region L, R _MIN is 25 μm or more and less than 30 μm. In the region M, R _MIN is 30 μm or more and less than 35 μm. In the region N, R _MIN is not less than 35 μm and less than 40 μm. In the region O, R _MIN is 40 μm or more and less than 45 μm. In the region _{P, R MIN} is less than 50μm more than 45 [mu] m.

As shown in FIGS. 9 and 10, R _MIN was smaller as the distances d ₁ and d ₂ were larger.

In each _RMIN described above, crosstalk to the adjacent lens does not occur. Further, the smaller the radius of curvature R, the higher the light collection efficiency and the higher the projection efficiency. Therefore, FIG. 9 and FIG. 10 are also the conditions for obtaining the maximum projection efficiency at the respective distances d ₁ and d ₂ . Therefore, the projection efficiency was measured using a projection lens with F (F-number) = 1.5 under the above conditions. 11 and 12 are graphs showing the relationship between the distances d ₁ and d ₂ and the projection efficiency.

  11 and 12, in region Q, the projection efficiency is 11.6% or more and less than 14.5%. In the region S, the projection efficiency is 14.5% or more and less than 17.4%. In the region T, the projection efficiency is 17.4% or more and less than 20.3%. In the region U, the projection efficiency is 20.3% or more and less than 23.2%.

In FIG. 11 and FIG. 12, since the contour line of the projection efficiency runs from the upper left to the lower right, it can be argued that the value of d ₁ + d ₂ can be centrally discussed. FIG. 13 is a graph showing the relationship between d ₁ + d ₂ and the projection efficiency in the case of FIG. 11 (n ₂ = 1.68) and the case of FIG. 12 (n ₂ = 1.46). The projection efficiency is the amount of light reaching the illumination target (for example, a screen) with respect to the amount of light emitted from the light emitting element 20.

From FIG. 13, regardless of the value of n ₂ , the projection efficiency is high when d ₁ + d ₂ is 10 μm or more and 16 μm or less. This is an optimum value when p = 10 μm, and a geometric proportional relationship is established. Therefore, it can be said that the optimum value of d ₁ + d ₂ is 1.0 to 1.6 times p. .

When d ₁ + d ₂ is increased, the minimum value R _{MIN of the} radius of curvature is decreased, the light emission angle is narrowed, and a large amount of light can be swallowed into the projection lens. However, if d ₁ + d ₂ is too large, the distance from the light emitting element 20 to the lens array 52 increases, and the amount of light that can be captured by the projection lens decreases. Therefore, d ₁ + d ₂ has the optimum value as described above.

As shown in FIG. 8, the distance between the lens array 52 and the point D and d _3, the size of the light emitting element 20 in a plan view when the w, derivable following equation (12). Furthermore, the following formula (13) can be derived from the formula (6). And from the formula (12) and the formula (13), the following formula (14) can be derived.

  In the light emitting device 300, the first light emitting element 20 a among the plurality of light emitting elements 20 is adjacent to the second light emitting element 20 b among the plurality of light emitting elements 20, and the light emitted from the first light emitting element 20 a is a plurality of lenses. 50, the second lens 50b provided corresponding to the second light emitting element 20b is not totally reflected. Therefore, in the light emitting device 300, crosstalk of light emitted from the light emitting element 20 can be reduced.

  In the light emitting devices 100 and 200 described above, the light emitted from the first light emitting element 20a may not be totally reflected by the second lens 50b.

3.2. Method for Manufacturing Light-Emitting Device Next, a method for manufacturing the light-emitting device 300 according to the third embodiment will be described. The manufacturing method of the light emitting device 300 according to the third embodiment is basically the same as the manufacturing method of the light emitting device 200 according to the second embodiment described above. Therefore, the detailed description is abbreviate | omitted.

3.3. Modification of Light Emitting Device Next, a light emitting device according to a modification of the third embodiment will be described with reference to the drawings. FIG. 14 is a cross-sectional view schematically showing a light emitting device 310 according to the third embodiment. 14 and FIGS. 15 to 18 described later, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other.

  Hereinafter, the light emitting device 310 according to the modification of the third embodiment will be described with respect to differences from the above-described example of the light emitting device 300 according to the third embodiment, and description of similar points will be omitted.

In the light-emitting device 300 described above, as shown in FIG. 6, the entrance surface 51a of the lens 50 is a flat surface, and the exit surface 51b is a curved surface. On the other hand, in the light emitting device 310, as shown in FIG. 14, both the entrance surface 51a and the exit surface 51b of the lens 50 are curved surfaces. In the light emitting device 310, the lens 50 is a biconvex lens.

  In the light emitting device 310, for example, the light beam L3 (total reflection light beam) shown in FIG. 6 can be removed. Among the plurality of lenses 50, the third lens 50c is a lens adjacent to the second lens 50b on the −X axis direction side of the second lens 50b. Of the plurality of light emitting elements 20, the third light emitting element 20c is a lens adjacent to the second light emitting element 20b on the −X axis direction side of the second light emitting element 20b. The third lens 50c is provided corresponding to the third light emitting element 20c.

  Here, FIG. 15 is a cross-sectional view schematically showing a light emitting device according to a reference example. The light rays totally reflected by the third lens 50c are light hitting the region E as shown in FIG.

  The light beam emitted from the first light emitting element 20a and traveling to the incident surface 51a of the second lens 50b is refracted by the second lens 50b and travels as the light beam L4, or refracted by the third lens 50c and travels as the light beam L5. Or one of them. In such a ray, the light traveling through the region F to the region E does not exist geometrically. Therefore, in the biconvex lens, the amount of light totally reflected by the third lens 50c is extremely small.

  The light that becomes crosstalk by the biconvex lens as described above is a light beam L6, a light beam L7, and a light beam L8. The light ray L6 is a light ray that is totally reflected by the first lens 50a. The light ray L7 is a light ray that is totally reflected by the second lens 50b. The light beam L8 is a light beam that is once emitted from the second lens 50b and then reenters the third lens 50c.

  Since the light beams L6 and L7 are light beams that enter the region G of the first lens 50a, crosstalk can be reduced if a structure that does not geometrically enter the region G is employed.

In the light emitting device 310, as shown in FIG. 16, when a tangent line is drawn from the end of the light emitting element 20 on the −X axis direction side to the incident surface 51a of the first lens 50a, a region G can be secured outside the contact. Further, the radius of curvature R ₁ , the distance d ₁ , and the pitch p of the incident surface 51a are defined.

  On the other hand, the light beam L8 in FIG. 15 re-enters the third lens 50c because the second lens 50b bends too much. Therefore, it is effective to make the curvature radius R2 of the emission surface 51b smaller than the curvature radius R1. Intuitively, it seems that the radius of curvature R2 must be increased. However, since light originally enters the lens 50 at a deep angle, it is correct to decrease the radius of curvature R2.

  17 and 18 are cross-sectional views schematically showing the light emitting device 310. FIG. FIG. 17 shows a case where R1 = R2 = 80 μm. FIG. 18 shows a case where R1 = 80 μm and R2 = 70 μm.

  In FIG. 17, the light beam L8 is incident on the third lens 50c again. On the other hand, in FIG. 18, the light beam L8 does not bend too much by the second lens 50b, and therefore does not re-enter the third lens 50c.

4). Fourth embodiment 4.1. Projector Next, a projector according to a fourth embodiment will be described with reference to the drawings. FIG. 19 is a diagram schematically illustrating a projector 400 according to the fourth embodiment.

The projector according to the present invention includes the light emitting device according to the present invention. Below, the projector 400 which has the light-emitting device 100 as a light-emitting device based on this invention is demonstrated.

  The projector 400 includes a housing (not shown), and a red light source 100R, a green light source 100G, and a blue light source 100B that respectively emit red light, green light, and blue light provided in the housing. . Each of the red light source 100R, the green light source 100G, and the blue light source 100B is the light emitting device 100. For convenience, FIG. 19 omits the illustration of the casing constituting the projector 400. In FIG. 19, the light sources 100R, 100G, and 100B are shown in a simplified manner.

  The projector 400 further includes transmissive liquid crystal light valves (light modulation devices) 402R, 402G, and 402B and a projection lens (projection device) 406 provided in the housing. The projector 400 is an LCD (Liquid Crystal Display) projector.

  Light emitted from the light sources 100R, 100G, and 100B is incident on the liquid crystal light valves 402R, 402G, and 402B. Each of the liquid crystal light valves 402R, 402G, and 402B modulates incident light according to image information. The projection lens 406 enlarges and projects the image (image) formed by the liquid crystal light valves 402R, 402G, and 402B onto the screen (display surface) 408. That is, the projection lens 406 projects the light emitted from the light sources 100R, 100G, and 100B onto the screen.

  Further, the projector 400 can include a cross dichroic prism (color light combining unit) 404 that combines the light emitted from the liquid crystal light valves 402R, 402G, and 402B and guides the light to the projection lens 406.

  The three color lights modulated by the respective liquid crystal light valves 402R, 402G, and 402B are incident on the cross dichroic prism 404. The cross dichroic prism 404 is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 408 by the projection lens 406, which is a projection optical system, and an enlarged image is displayed.

4.2. Modification Example of Projector 4.2.1. First Modification Next, a projector according to a first modification of the fourth embodiment will be described with reference to the drawings. FIG. 20 is a cross-sectional view schematically showing a projector 410 according to a first modification of the fourth embodiment. For convenience, in FIG. 20, the light sources 100R, 100G, and 100B are shown in a simplified manner. In FIG. 20, the screen 408 is not shown.

  Hereinafter, in the projector 410 according to the first modification example of the fourth embodiment, differences from the example of the projector 400 according to the fourth embodiment described above will be described, and description of similar points will be omitted. This is the same in the projector according to the second modification of the fourth embodiment to be described later.

In the projector 400 described above, as shown in FIG. 19, a transmissive liquid crystal light valve is used as the light modulation device. On the other hand, as shown in FIG. 20, the projector 410 uses a DMD (Digital Micromirror Device, registered trademark) 418 as a light modulation device. The projector 410 is a DLP (Digital Light Processing (registered trademark) projector.

  The projector 410 includes light sources 100R, 100G, and 100B, dichroic filters 411 and 412, lenses 413, 414, 415, and 416, an internal total reflection prism (TIR prism) 417, a DMD 418, and a projection lens 406. is doing.

  The light emitted from the red light source 100 </ b> R is reflected by the dichroic filter 411 and enters the lens 413. The light emitted from the green light source 100 </ b> G is reflected by the dichroic filter 412, passes through the dichroic filter 411, and enters the lens 413. The light emitted from the blue light source 100 </ b> B passes through the dichroic filters 411 and 412 and enters the lens 413. Light emitted from the light sources 100R, 100G, and 100B is combined in the dichroic filter 411.

  The light emitted from the lens 413 enters the TIR prism 417 via the lenses 414, 415, and 416. The lens 414 is a rod lens (integrator), and light is repeatedly totally reflected inside the lens 414, whereby the illuminance distribution can be made substantially uniform at the exit of the lens 414. The lenses 413, 415, and 416 are, for example, condenser lenses.

  The light incident on the TIR prism 417 is reflected by the reflecting portion 417a and enters the DMD 418.

  The DMD 418 modulates incident light according to image information and reflects it. The light reflected by DMD 418 passes through TIR prism 417 and enters projection lens 406.

4.2.2. Second Modification Next, a projector according to a second modification of the fourth embodiment will be described with reference to the drawings. FIG. 21 is a cross-sectional view schematically showing a projector 420 according to a second modification of the fourth embodiment. For convenience, the screen 408 is not shown in FIG.

  The projector 400 described above has the light sources 100R, 100G, and 100B, which are the light emitting devices 100, as shown in FIG. On the other hand, the projector 420 includes light sources 200R, 200G, and 200B, which are light emitting devices 200, as shown in FIG. Since the light emitting device 200 is a self-luminous imager capable of forming pixels, the projector 420 does not have a separate light modulation device. Therefore, it is possible to reduce the size. For convenience, in FIG. 21, the light sources 200R, 200G, and 200B are illustrated in a simplified manner.

  The red light source 200R, the green light source 200G, and the blue light source 200B emit red light, green light, and blue light, respectively. Further, the projector 420 has a Philips prism 422.

  The light emitted from the light sources 200R, 200G, and 200B is combined in the Philips prism 422 and enters the projection lens 406. For example, since the light emitted from the light sources 200R, 200G, and 200B is non-polarized light, the Philips prism 422 with little polarization dependence is suitable.

Note that the light emitting device according to the present invention can also be applied to a device to which a projector such as an HMD (head mounted display) or a HUD (head up display) is applied. The light-emitting device according to the present invention can be widely applied to devices that require bright light with directivity, such as headlights and spotlights for automobiles, in addition to projectors.

5. Experimental Example An experimental example is shown below to describe the present invention more specifically. The present invention is not limited by the following experimental examples.

  In a model having a light emitting device corresponding to the light emitting device 100 and a projection lens of F = 1.5, a simulation was performed by ray tracing by the Monte Carlo method. Note that FIG. 24 shown below is not a simulation but an experimental result obtained by actually manufacturing a light emitting device and performing measurement.

  The model light-emitting device used for the simulation has 100,000 (100 × 100) light-emitting units (light-emitting units including light-emitting elements (LEDs) and lenses) arranged in a matrix. In the model, the contact region between the second semiconductor layer and the second electrode (hereinafter also simply referred to as “contact region”) is a square.

  FIG. 22 is a graph showing the relationship between the size of the contact area and the projection efficiency. The pitch between the LED and the lens (the pitch of the light emitting unit) was set to 10 μm. Projection efficiency is the intensity of light reaching the screen relative to the intensity of light emitted from the LED.

  As shown in FIG. 22, when the size of the contact area is smaller than 4 μm square, the projection efficiency is 40% or more.

  Next, FIG. 23 is a graph showing the relationship between the size of the contact area and the projected light beam (light beam projected on the screen). In FIG. 23, the projection light flux is 100 when there is no micro lens array (MLA) and the size of the contact area is 10 μm square (that is, when the light emitting layers of the LEDs are continuously arranged without gaps). As standardized.

  As shown in FIG. 23, in the case without MLA, the projected light flux was reduced in proportion to the area of the contact region. On the other hand, in the case of MLA, even when the size of the contact area became 4 μm square, it was possible to maintain a projected light beam exceeding 90%. When the size of the contact area is 4 μm square, the current injected into the light emitting layer of the LED can be reduced to 1/6 in order to obtain the same brightness as without MLA.

  Next, as an experiment corresponding to the light emitting device 100 using an LED as the light emitting element 20, the size of the contact region of the LED was changed variously, and the characteristics were measured. However, the shape of the contact area is a square. In addition, isolated LEDs were used instead of LEDs arranged in a matrix. FIG. 24 is a graph showing the relationship between the current density injected into the light emitting layer of the LED and the light power density of the LED. The size of the contact area was changed from 100 μm square to 1 μm square.

  As shown in FIG. 24, the optical power density tends to increase as the current density increases, but saturates at a certain current density. This is due to a droop phenomenon in which the luminous efficiency decreases when a large amount of power is applied to the LED.

As shown in FIG. 24, the smaller the size of the contact area, the greater the optical power density can be withstood. This can be understood as the smaller the size of the contact region, the lower the junction temperature due to heat radiation from the side surface of the light emitting layer, and the higher the quantum efficiency. However, when the size of the contact area is 2 μm square, the droop phenomenon suppressing effect is saturated. Further, in the case of an LED having a contact area smaller than 2 μm square, when the light emitting layer is patterned, the ratio of the light emitting layer that deteriorates due to patterning increases, and the light emission intensity may decrease. Therefore, the size of the contact region is preferably 2 μm square or more.

  Next, FIG. 25 is a graph showing the relationship between the size of the contact area, the current density, and the total current amount. In FIG. 25, “current density” indicates a limit current density at which the droop phenomenon occurs (current density when the optical power density is maximum in FIG. 24). In FIG. 25, “total current amount” is obtained by multiplying the current density by the size of the contact area.

As shown in FIG. 25, when the contact area was 10 μm square, the current density was as low as 2500 A / cm ² . This is because when the contact area is 10 μm square, adjacent contact areas are connected to form a 1 mm square contact area. When the contact area was 1 μm square, the current density could be increased to 28000 A / cm ² . When the contact area was 3 μm square or less, the total current amount was smaller than 25 A in the case of 10 μm square and decreased to 3 A in the 1 μm square.

  Next, FIG. 26 is a graph showing the relationship between the size of the contact area and the projected light flux when the current density is increased to the limit according to the size of the contact area as shown in FIG.

  As shown in FIG. 26, in the case of MLA, when the size of the contact area is 1 μm square or more and 9 μm square or less, the projected light beam becomes larger (brighter) than in the case of 10 μm square. In particular, when the size of the contact area is 4 μm square or more and 5 μm square or less, a projection light beam nearly 10 times as large as that of the 10 μm square is obtained. In the case with MLA, the projected light flux was larger than in the case without MLA.

  Next, FIG. 27 is a graph showing the relationship between the size of the contact area and the efficiency. In FIG. 27, “efficiency” is obtained by dividing the projected light flux of FIG. 26 by the total current amount of FIG. As shown in FIG. 27, the smaller the contact area, the higher the efficiency.

  Next, FIG. 28 is a graph showing the relationship between the ratio (d / p) of the size (length of one side) d of the contact area to the pitch p of the LED and the lens, and the projected light flux.

  As shown in FIG. 28, when the ratio (d / p) is not less than 0.4 and not more than 0.5, the projected light flux becomes high. Further, the smaller the pitch p, the higher the projected luminous flux, but it was saturated at 12 μm. Therefore, it can be said that the pitch p is preferably 12 μm or less.

  Next, FIG. 29 is a graph showing the relationship between the ratio (d / p) and efficiency. As shown in FIG. 29, when the pitch p was 5 μm or more and 12 μm or less, the ratio (d / p) was 0.5 and there was an inflection point. In order to improve the efficiency, it was found that the ratio (d / p) is preferably 0.1 or more and 0.5 or less. In particular, the efficiency can be improved by setting the ratio (d / p) to 0.1 or more and 0.3 or less.

  From FIG. 24, the size of the contact area is 2 μm square or more, the pitch p is 12 μm or less from FIG. 28, and the ratio (d / p) is 0.5 or less from FIG. It was found that can be illuminated efficiently.

  In the present invention, a part of the configuration may be omitted within a range having the characteristics and effects described in the present application, or each embodiment or modification may be combined.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 2 ... Light emitting unit, 10 ... Board | substrate, 20 ... Light emitting element, 20a ... 1st light emitting element, 20b ... 2nd light emitting element, 20c ... 3rd light emitting element, 22 ... 1st semiconductor layer, 24 ... Light emitting layer, 26 ... 1st 2 semiconductor layers, 28 ... columnar part, 30 ... first electrode, 32 ... second electrode, 34 ... contact region, 40 ... insulating layer, 50 ... lens, 50a ... first lens, 50b ... second lens, 50c ... first 3 lenses, 51a ... incident surface, 51b ... output surface, 52 ... lens array, 60 ... substrate, 62 ... heat sink, 64 ... drive circuit board, 70 ... insulating layer, 80 ... first through via, 82 ... second through via 84 ... Pad, 86 ... Wiring, 100 ... Light emitting device, 100R ... Red light source, 100G ... Green light source, 100B ... Blue light source, 200 ... Light emitting device, 200R ... Red light source, 200G ... Green light source, 200B ... Blue light source, 300 , 3 DESCRIPTION OF SYMBOLS 0 ... Light-emitting device, 400 ... Projector, 402R, 402G, 402B ... Liquid crystal light valve, 404 ... Cross dichroic prism, 406 ... Projection lens, 408 ... Screen, 410 ... Projector, 411, 412 ... Dichroic filter, 413, 414, 415 , 416 ... Lens, 417 ... TIR prism, 417a ... Reflector, 418 ... DMD, 420 ... Projector, 422 ... Philips prism

Claims (5)

A plurality of light emitting units having a light emitting element and a lens provided corresponding to the light emitting element;
The light emitting element is
A first semiconductor layer;
A second semiconductor layer having a conductivity type different from that of the first semiconductor layer;
A light emitting layer provided between the first semiconductor layer and the second semiconductor layer and capable of generating light by injecting a current;
A first electrode electrically connected to the first semiconductor layer;
A second electrode in contact with the second semiconductor layer;
Have
In a plan view seen from the stacking direction of the first semiconductor layer and the light emitting layer, the second electrode overlaps the light emitting layer,
In a plan view seen from the stacking direction, the plurality of light emitting units are arranged at a pitch p in the first direction,
The size d in the first direction of the contact region between the second semiconductor layer and the second electrode, and the pitch p are:
d / p ≦ 0.5, d ≧ 2 μm, and p ≦ 12 μm
A light-emitting device that satisfies the above relationship. In claim 1,
The size d and the pitch p are:
0.4 ≦ d / p ≦ 0.5
A light-emitting device that satisfies the above relationship. In claim 1,
The size d and the pitch p are:
d / p ≦ 0.3
A light-emitting device that satisfies the above relationship. In any one of Claims 1 thru | or 3,
The first light emitting element among the plurality of light emitting elements is adjacent to the second light emitting element among the plurality of light emitting elements,
The light emitted from the first light emitting element is not totally reflected by the lens provided corresponding to the second light emitting element among the plurality of lenses. A light emitting device according to any one of claims 1 to 4,
A projection device for projecting light emitted from the light emitting device;
Having a projector.

Images