JP7719236B2 - Light-emitting device, display device, exposure system, and display/imaging device - Google Patents

Description

The present invention relates to light-emitting devices, display devices, exposure systems, display and imaging devices, photoelectric conversion devices, electronic devices, lighting devices, and mobile objects.

An organic EL element is a light-emitting element that has a pair of electrodes and an organic compound layer, including a light-emitting layer, disposed between them. Light-emitting devices that use organic EL elements have excellent features such as surface emission characteristics and light weight. Taking advantage of these features, they have attracted attention as light-emitting devices for use in display and imaging devices such as head-mounted displays and exposure devices in exposure systems for electrophotographic printers.

When a light-emitting device is used as a display device or exposure device, the light emitted from the light-emitting device is used through various optical systems. The optical systems only use a portion of the light emitted from the light-emitting device. For this reason, it is thought that the power consumption of the light-emitting device can be reduced by improving the light utilization efficiency of the optical systems.

Patent document 1 discloses a configuration in which microlenses are provided on organic EL elements in order to increase the light emission intensity in the front direction.

JP 2012-248453 A

The light-emitting device described in Patent Document 1 may not have sufficient light utilization efficiency when combined with an optical system.

One aspect of the present invention is a light emitting device having a first chip and a second chip on a main surface of a substrate, wherein the first chip has, as a light emitting portion , only a set of a first light emitting element and a first lens that overlaps in a planar view with the midpoint of a first light emitting region of the first light emitting element in a cross section perpendicular to the substrate , and the second chip has, as a light emitting portion, only a set of a second light emitting element and a second lens that overlaps in a planar view with the midpoint of a second light emitting region of the second light emitting element in a cross section perpendicular to the substrate, wherein, in a planar view , an apex of the first lens that is the farthest point from the substrate on the first lens is away from the midpoint of the first light emitting region in a positive direction in a first direction, and the apex of the second lens that is the farthest point from the substrate on the second lens is away from the midpoint of the second light emitting region in a negative direction in the first direction.

It is possible to provide a light-emitting device with improved light utilization efficiency.

1A is a schematic cross-sectional view illustrating an example of the configuration of a portion of an exposure system, and FIG. 1B is a schematic plan view. FIG. 2 is a schematic diagram showing a light beam from a light emitting device in a magnifying optical system. 1A is a cross-sectional view showing an example of a part of an exposure system using a light-emitting device, and FIG. 1B is a schematic diagram when viewed in plan. 10 is a cross-sectional view illustrating the relationship between the arrangement of light-emitting regions and microlenses and light rays. FIG. 10 is a cross-sectional view illustrating the relationship between the arrangement of light-emitting regions and microlenses and light rays. FIG. FIG. 10 is a cross-sectional view illustrating a modified example of the light-emitting device. 1A and 1B are schematic plan views showing examples of arrangements of light-emitting devices and microlenses. FIG. 1 is a cross-sectional view showing an example of an aspherical lens. FIG. 1A is a schematic cross-sectional view showing an example of a portion of a display device using a light-emitting device; FIG. 1B is a schematic diagram for explaining the arrangement of light-emitting elements and microlenses; and FIG. 1C is a schematic plan view showing an example of a portion of a display device using a light-emitting device. FIG. 1 is a cross-sectional view showing a configuration example of an exposure system that does not have a color filter. 10A and 10B are cross-sectional schematic diagrams for explaining an example in which an aspherical lens is used in a light emitting device. 1A and 1B are schematic diagrams illustrating application examples of a light emitting device. 1 is a schematic cross-sectional view of an example of a display and imaging device. FIG. 1 is a schematic cross-sectional view of an example of a display device. 1A is a schematic diagram showing an example of a display photoelectric conversion device, and FIG. 1B is a schematic diagram showing an example of an electronic device. FIG. 1A is a schematic diagram showing an example of a display device, and FIG. 1B is a schematic diagram showing an example of a foldable display device. 1A is a schematic diagram showing an example of a lighting device, and FIG. 1B is a schematic diagram showing an example of an automobile having a vehicle lamp.

Figures 1(a) and (b) show an example of the configuration of an exposure system in which light emitted from a light-emitting device using organic EL elements as light-emitting elements is imaged onto a photosensitive member through an imaging lens array. Figure 1(b) is a schematic plan view, and Figure 1(a) is a cross-sectional view of the A-A' cross section in Figure 1(b).

As shown in Figure 1(b), in the case of a light-emitting device 2 in which chips each having multiple light-emitting elements 100 are arranged in a staggered pattern, the pixels each having a light-emitting element are not located directly below the imaging lens array 3. Furthermore, when multiple pixels are arranged in the sub-scanning direction as shown in Figures 1(a) and 1(b) in order to expose the same point on the photosensitive member multiple times, the angle at which light from the outer pixels is directed toward the imaging lens array increases. In such cases, it is believed that light utilization efficiency can be improved by increasing the light emission intensity in the direction from the pixel toward the imaging lens array.

Figure 2 shows an overview of the light rays when a light-emitting device having an organic EL element is used in a display device that uses a magnifying optical system. As shown in the figure, when a magnifying optical system 6 is used with the light-emitting device 2, the center of the functional area (display area) uses light rays that are directed in a direction directly toward the display surface. On the other hand, the periphery of the functional area uses light that is directed in an oblique direction toward the display surface. Therefore, it is thought that light utilization efficiency can be improved by increasing the light emission intensity in an oblique direction in the periphery of the functional display area.

The inventors came up with this idea and arrived at a solution by displacing the center of a microlens from the light-emitting region of the light-emitting element in the direction in which the light-emitting intensity is desired to be increased. Below, an embodiment of the present invention will be described with reference to the drawings. Note that well-known or publicly known techniques in the relevant technical field apply to parts not specifically shown or described in this specification. Furthermore, the present invention is not limited to the embodiments described below.

Furthermore, in the following description and drawings, common reference numerals are used to designate components that are common across multiple drawings. Therefore, the common components will be described by mutually referencing multiple drawings, and descriptions of the components, materials, methods, effects, etc. that are designated by common reference numerals will be omitted as appropriate.

(Embodiment 1)
An example of the configuration of the light emitting device of this embodiment will be described below. In this embodiment, an example of an exposure system will be described in which light emitted from the light emitting device is irradiated onto a photosensitive member through an imaging lens array to form an image.

The light-emitting device of this embodiment has a light-emitting element arranged on the main surface of a substrate, and a microlens fixed to the substrate and onto which light from the light-emitting region of the light-emitting element is incident. In a plan view from a direction perpendicular to the main surface of the substrate, the center of the light-emitting region and the center of the microlens are separated by a distance in a direction parallel to the main surface.

A plurality of light-emitting regions and microlenses may be arranged, and in a planar view from a direction perpendicular to the main surface, for example, the distance between the center of the second light-emitting region and the center of the second microlens may be smaller than the distance between the center of the first light-emitting region and the center of the first microlens in the parallel direction.

Furthermore, in the parallel direction, the distance from the center of the first microlens to the center of the second microlens may be different from the distance from the center of the first light-emitting region to the center of the second light-emitting region.

Furthermore, for example, the light emitting device of this embodiment has first to third light emitting elements arranged on the main surface of the substrate, and first to third microlenses onto which light from the light emitting regions of the first to third light emitting elements is incident, respectively. Furthermore, the first to third pixels, each having the first to third light emitting elements, emit light of the same color, and when viewed from the first to third pixels alone, the second light emitting element is arranged adjacent to and between the first and third light emitting elements in a plan view perpendicular to the main surface.

In this configuration, when viewed in a plan view perpendicular to the main surface, the difference between the distance between the vertex of the first microlens and the vertex of the second microlens and the distance between the vertex of the second microlens and the vertex of the third microlens is defined as the pitch difference D.

In this case, in the light-emitting device of this embodiment, the distance between the center of the second light-emitting region and the vertex of the second microlens in plan view is greater than the pitch difference D.

In a plan view perpendicular to the main surface, the distance between the center of the second light-emitting region and the vertex of the second microlens may be smaller than the distance between the center of the first light-emitting region and the vertex of the first microlens. In this case, the distance refers to the distance (shortest distance) in a direction passing through the vertex of the first microlens and the vertex of the second microlens.

Furthermore, in the parallel direction, the pitch of the microlenses and the pitch of the light-emitting regions may be different. For example, the distance from the apex of the first microlens to the apex of the second microlens may be different from the distance from the center of the first light-emitting region to the center of the second light-emitting region.

A more specific configuration example will be described using the drawings. Figure 3(a) is a cross-sectional view showing an example of a portion of an exposure system using the light-emitting device of this embodiment, and Figure 3(b) is a schematic diagram when viewed from a plan view. A plan view refers to the arrangement of the light-emitting device when viewed from a direction perpendicular to the main surface of the substrate (the normal direction to the main surface). Here, a plan view from a direction perpendicular to the main surface of the substrate is shown.

The light-emitting device has a light-emitting element 100, and the light-emitting element 100 on the substrate 8 has a first electrode 11 arranged on the main surface of the substrate 8, an organic layer 12 including a light-emitting layer, and a second electrode 13 arranged on the first electrode 11 with the organic layer 12 sandwiched between them. The light-emitting device also has an insulating layer 16 that covers the end of the first electrode 11, has an opening on the first electrode 11, and functions as a bank, a protective layer 14 arranged on the second electrode 13, and a microlens 15. Light emitted from the light-emitting element is incident on the microlens 15.

In this embodiment, the microlenses 15 are arranged offset in direction B toward the imaging lens array 3 relative to the light-emitting region 17 of the light-emitting element 100 in plan view. This configuration increases the light emission intensity in the direction toward the imaging lens array 3 compared to when no microlenses are formed or when the microlenses and light-emitting region are formed to overlap in plan view, improving the efficiency of use of light emitted by the light-emitting layer. Details of this effect will be described later. Note that the light-emitting region of the light-emitting element refers to the portion where the first electrode 11, light-emitting layer, and second electrode 13 are stacked in the opening of the insulating layer 16 in plan view.

In each light-emitting element, the microlens and the light-emitting area are misaligned, meaning that the center of the microlens and the center of the light-emitting area do not overlap in a planar view, but are separated by a certain distance. The center of the microlens is the center of gravity of the shape (external shape) formed by the lines connecting the ends in a planar view. The end of the microlens is the position where the height in the Z direction is lowest in the cross-sectional view of the microlens. In Figure 3(a), the cross-section of microlens 15 is spherical (spherical shapes also include partially missing spheres and hemispheres), and in this case, the center of microlens 15 coincides with the vertex of microlens 15.

In this embodiment, the microlens 15 is positioned so as to be offset from the light-emitting area. That is, in a plan view of the surface of the substrate 8 on which the light-emitting elements 100 are arranged, the center of the microlens 15 and the center of the light-emitting area are separated by a certain distance (they do not coincide). In addition, because the cross-sectional shape of the microlens 15 here is spherical, the apex of the microlens 15 and the center of the light-emitting area are also separated by a certain distance.

In this embodiment, the pitch of the microlenses 15 (the distance between the centers of adjacent microlenses in a planar view relative to the surface of the substrate 8 on which the light-emitting elements 100 are arranged) is constant. The pitch of the light-emitting elements (the distance between the centers of the light-emitting regions of adjacent light-emitting elements 10 in the planar view) is also constant. Therefore, the microlenses 15 and the light-emitting regions 10 are arranged with a constant offset (amount of offset).

Furthermore, the pitch of the light-emitting elements and the pitch of the microlenses 15 are substantially equal. In other words, this embodiment shows an example in which the distance between the center of the microlens and the center of the light-emitting area in a planar view (microlens shift amount) is constant for each light-emitting element.

The pitch of the microlenses 15 can be 0.1 to 20 times the pitch of the light-emitting elements. Specifically, the pitch of the light-emitting elements can be, for example, 0.1 μm to 40 μm, and the pitch of the microlenses 15 can be 0.01 μm to 800 μm. Furthermore, in this embodiment, the distance from the second electrode 13 of the light-emitting element to the microlenses 15 can be 0.1 μm to 1 mm.

The substrate 8 may be made of any material that can support the first electrode 11, organic layer 12, and second electrode 13. For example, glass, plastic, silicon, etc. may be used. The substrate 8 may also be provided with switching elements such as transistors, wiring, an interlayer insulating film (not shown), etc.

The first electrode 11 may be transparent or opaque. If it is opaque, a metal material with a reflectance of 70% or more at the emission wavelength is desirable. Metals such as Al and Ag, alloys of these with Si, Cu, Ni, Nd, etc., as well as ITO, IZO, AZO, and IGZO can be used. Note that the emission wavelength here refers to the spectral range emitted from the organic layer 12. As long as the first electrode 11 has a reflectance higher than the desired one, it may be a laminated electrode with a barrier electrode made of a metal such as Ti, W, Mo, or Au or an alloy thereof, or a laminated electrode with a transparent oxide film electrode such as ITO or IZO.

On the other hand, if the first electrode 11 is a transparent electrode, a reflective layer may be further provided below the first electrode 11. Examples of transparent electrodes that can be used include ITO, IZO, AZO, and IGZO. To optimize the optical path (described later), an insulating film may be further provided between the reflective layer and the transparent conductive film.

The second electrode 13 is disposed on the organic layer 12 and is light-transmitting. The second electrode 13 may be made of a semi-transparent material that transmits part of the light that reaches its surface and reflects the other part (i.e., semi-transparent and semi-reflective).

The second electrode 13 may be made of a transparent material such as a transparent conductive oxide. Alternatively, a semi-transparent material made of an elemental metal such as aluminum, silver, or gold, an alkali metal such as lithium or cesium, or an alkaline earth metal such as magnesium, calcium, or barium, or an alloy containing these metal materials may be used. As a semi-transparent material, an alloy primarily composed of magnesium or silver is particularly preferable. The second electrode 13 may also have a stacked structure of layers containing the above materials, as long as it has a desired transmittance. The second electrode 13 may also be shared by multiple light-emitting elements 100.

Either the first electrode 11 or the second electrode 13 functions as an anode, and the other functions as a cathode. That is, the first electrode 11 may be an anode and the second electrode 13 may be a cathode, or vice versa.

The organic layer 12 is disposed on the first electrode 11 and can be formed using known techniques such as vapor deposition or spin coating.

The organic layer 12 may be composed of multiple layers. When the organic layer is an organic compound layer, the multiple layers may include one or a combination of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

The light-emitting layer emits light when holes injected from the anode and electrons injected from the cathode recombine in the organic compound layer. The light-emitting layer may be a single layer or multiple layers. Any of the light-emitting layers may contain a red light-emitting material, a green light-emitting material, and a red light-emitting material, and white light can be obtained by mixing the emitted colors. Any of the light-emitting layers may also contain light-emitting materials of complementary colors, such as a blue light-emitting material and a yellow light-emitting material.

Also, different colors may be emitted by changing the material or composition of the light-emitting layer for each light-emitting pixel. Alternatively, a light-emitting layer may be provided for each light-emitting element. In this case, the light-emitting layer may be patterned for each light-emitting element 100.

The light-emitting device according to this embodiment may include an element having a first reflective surface, a second reflective surface, and a light-emitting layer disposed between the first reflective surface and the second reflective surface. The light-emitting element described above may have this configuration. The first reflective surface may be the first electrode 11, or a reflective layer disposed between the first electrode 11 and the insulating layer.

In order to optimize the optical distance between the first reflecting surface and the light-emitting position of the organic layer 12 including the light-emitting layer, let Lr be the optical path length from the upper surface of the first reflecting surface to the light-emitting position of the organic layer 12, and Φr be the phase shift in the reflecting layer.
Lr=(2m-(Φr/π))×(λ/4)...(1)
m is an integer equal to or greater than 0. The film thickness of the first electrode 11 or the first reflecting surface and the organic layer 12 may be optimized so as to approximately satisfy the above formula (1).

Furthermore, the optical distance Ls from the light-emitting position to the second reflecting surface approximately satisfies the following formula (2), where Φs is the phase shift that occurs when light of wavelength λ is reflected by the reflecting surface. In this embodiment, m′=0.
Ls=(2m'-(Φs/π))×(λ/4)=-(Φs/π)x(λ/4)...(2)

Therefore, the total layer interference L approximately satisfies the following condition:
L=Lr+L=(2m-Φ/π)×(λ/4)...(3)

Here, Φ is the sum of the phase shifts Φr + Φs when light of wavelength λ is reflected by the first electrode 11 or the reflective layer and the second electrode 13.

In this context, "approximately satisfying" means that the tolerance range in equations (1) to (3) is approximately λ/8 or approximately 20 nm.

Note that since it can be difficult to identify the light-emitting position of the light-emitting layer, in the above configuration, the interface on the first reflecting surface side or the interface on the second reflecting surface side of the functional layer is used as the light-emitting position. Taking into account the tolerance ranges mentioned above, even when using this substitution, the effect of intensifying light can be achieved.

The protective layer 14 is an insulating layer, and preferably contains an inorganic material that is translucent and has low permeability to oxygen and moisture from the outside. For example, the protective layer 14 can be made using inorganic materials such as silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiO _x ), aluminum oxide (Al ₂ O ₃ ), and titanium oxide (TiO ₂ ). In particular, inorganic materials such as SiN, SiON, and Al ₂ O ₃ are preferred in terms of protective performance. The protective layer 14 is preferably formed by chemical vapor deposition (CVD), atomic layer deposition (ALD), or sputtering.

Protective layer 14 may have a single layer structure or a laminated structure that combines the above materials and formation methods, as long as it has sufficient moisture-blocking properties. For example, it may be a laminate of a silicon nitride layer and a high-density layer formed by atomic deposition. Furthermore, protective layer 14 may have an organic layer, as long as it maintains moisture-blocking properties. Examples of organic layers include polyacrylate, polyimide, polyester, and epoxy.

Furthermore, the protective layer 14 may be disposed across multiple light-emitting elements 100.

The microlenses 15 can be formed using an exposure and development process. Specifically, a film (photoresist film) is formed from the material used to form the microlenses, and the photoresist film is exposed and developed using a mask with continuous gradation changes. Such a mask can be a gray mask, or an area gradation mask, which changes the density distribution of dots made of a light-shielding film below the resolution of the exposure device, allowing light to be irradiated with continuous gradations on the imaging surface.

In addition, the lens shape can be adjusted by etching back the microlenses formed by the exposure and development process. The shape of the microlenses can be any shape that can refract the emitted light, and they can be spherical or have an asymmetric cross-sectional shape.

The effects of this embodiment will be explained. As shown in Figure 4(a), when the microlens and light-emitting area are arranged so that they overlap in a planar view, the light emitted from the light-emitting area is focused in the front direction by the microlens. Therefore, the light emission intensity in the front direction is improved compared to when no microlens is provided. On the other hand, when the microlens is arranged offset from the light-emitting area as shown in Figure 4(b), the light is refracted as it passes through the microlens, improving the light emission intensity in a specific direction.

In an exposure system, as described above, when chips having light-emitting elements are arranged in a staggered pattern, pixels having light-emitting elements are not located directly below the imaging lens array. Furthermore, when multiple pixels are arranged in the sub-scanning direction, the angle at which light from the outer pixels is directed toward the imaging lens array increases. Therefore, by using a light-emitting device with improved light emission intensity in a specific direction, as in this embodiment, it is possible to increase the light emission intensity in the direction from the pixel toward the imaging lens array. This makes it possible to provide an exposure system with improved light utilization efficiency.

For example, a light-emitting device used in an exposure system has multiple sets of light-emitting regions and microlenses onto which light from the light-emitting regions is incident. In this case, in the multiple sets, the direction from the center of the light-emitting region toward the center of the microlens in a direction parallel to the surface of the substrate 8 on which the light-emitting elements 100 are arranged is one direction, specifically the direction toward the imaging lens array 3. This makes it possible to increase the emission intensity of light passing through the microlenses arranged in the functional region (light-emitting region) where the multiple sets are arranged, in the direction toward the imaging lens array. This improves light utilization efficiency.

Figure 5 is a cross-sectional view showing the relationship between the light-emitting area and the microlenses. Figure 5 shows microlenses with height h, radius r, and refractive index n.

Light is emitted from the light-emitting region at an angle θ1 and is bent at an angle θ2 by point A of the microlens. The angle at which the normal to the tangent to the microlens surface at point A is inclined is defined as angle α. If α + θ1 is defined as β, then the following equation (1) holds according to Snell's law:
1×sin(θ2+α)==n×sin(θ1+α)...(1)

When equation (1) is solved for θ1, θ1 becomes equation (2).
θ1=sin ^-1 {sin(θ2+α)/n}-α...(2)

As shown in Figure 5, when it is desired to emit light from the light-emitting area toward the wide-angle side (when θ2 > θ1 is desired), the light that enters the area where α is positive, i.e., the area to the right of the apex of the microlens in Figure 5, will be mainly used.

In order to effectively utilize the microlens right up to its edges, it is desirable that α<θ2 be satisfied across the entire area of the microlens, where θ2 is the desired emission angle at which the emission intensity is to be increased.

Here, Xshift is the amount of deviation between the vertex of the microlens and the center of the light-emitting area. To increase the emission intensity at the desired emission angle θ2, θ1 and β that satisfy equation (2) above are calculated for α at each point on the microlens, and Xshift is set so that the light-emitting area X exists in the direction of one of the βs.

In reality, there are protective layers and other layers between the microlenses and the light-emitting area, so the above formula does not determine this. However, based on the above effect, it is believed that by configuring the microlenses to be offset from the light-emitting area, the light intensity in a specific direction can be improved, and the light utilization efficiency of the optical system can be improved.

Figure 3(a) shows an example in which the microlenses 15 are formed integrally (continuously) directly on the protective layer 14. A planarizing layer may be formed between the protective layer 14 and the microlenses 15 in order to smooth out any irregularities in the protective layer 14. A color filter may also be disposed between the microlenses 15 and the protective layer 14, or between the microlenses 15 and the planarizing layer. Furthermore, a color filter may also be disposed on top of the microlenses 15.

Figure 6(a) shows an example in which a color filter 18 is arranged in the light-emitting device shown in Figure 3(a). Here, an example is shown in which a color filter is arranged between the microlens 15 and the protective layer 14. Also, here, an example is shown in which only pixels that emit light of the same color (e.g., green) are cut out from a light-emitting device in which pixels having red, green, and blue color filters are arranged adjacent to each other.

For pixels that emit light of the same color, the light-emitting device of this embodiment satisfies the following relationship for three pixels that are arranged adjacently in a planar view relative to the surface of the substrate 8 on which the light-emitting elements 100 are arranged. In this planar view, the distance X between the center of the light-emitting region and the vertex of the microlens is greater than the difference between the distance between the vertex of microlens 15a and the vertex 15b of the second microlens, and the distance between the vertex of microlens 15b and the vertex 15c of the microlens. In Figure 6(a), the pitch of the microlenses 15 is constant, so the center of the light-emitting region and the vertex of the microlens (the vertex in this case) are arranged with a misalignment.

This makes it possible to improve the light emission intensity in a specific direction and improve the light utilization efficiency in the optical system (imaging lens array 3 and third optical system 6).

Alternatively, as shown in FIG. 6(b), the microlens 15 may be formed on a separate substrate and attached to it so as to face the light-emitting element 100. For example, the microlens 15 may be fixed to the substrate 8 with an adhesive. In this case, the adhesive may be between the protective layer 14 and the microlens 15, or between the planarization layer and the microlens 15. Alternatively, a space may be provided between the microlens 15 and the protective layer 14 (or the planarization layer, or the color filter), and the microlens 15 may be fixed to the substrate 8 with an adhesive at the edge of the light-emitting device.

Even in this case, as shown in Figure 6(c), by positioning the microlens offset from the light-emitting area, the light is refracted as it passes through the microlens, increasing the light emission intensity in a specific direction. This improves the light utilization efficiency of the optical system.

When the microlens 15 and protective layer 14 are formed integrally, the distance between the microlens 15 and the light-emitting element 100 can be made shorter than when they are formed on separate substrates and then bonded together. This widens the solid angle of light incident on the microlens from the light-emitting layer, improving light extraction efficiency.

On the other hand, by separately creating the substrate 8 on which the microlens 15 and light-emitting element 100 are arranged and then bonding them together, the options for manufacturing the microlens 15 can be increased, thereby improving the design freedom of the microlens 15.

Next, an example of the arrangement of microlenses 15 and light-emitting areas is shown. Figures 3(a) and (b) show an example in which one microlens is provided for one light-emitting element, but multiple microlenses may be provided for one light-emitting element, as shown in Figure 7(a). Also, one microlens may be shared by multiple light-emitting elements, as shown in Figure 7(b). When multiple microlenses 15 are provided for one light-emitting element 100, it is sufficient that the midpoint C3 of the centers C1 and C2 of each microlens 15 and the center of the light-emitting area are separated (shifted) by a certain distance, as shown in Figure 7(a).

When three or more microlenses 15 are provided for one light-emitting element and the centers of the microlenses 15 are not on a straight line, it is sufficient that the center of gravity of the figure formed by connecting the centers of the microlenses is offset from the center of the light-emitting area.

When one microlens is shared by multiple light-emitting elements, the center of the microlens needs to be offset from the center of the midpoint C6 between the centers C4 and C5 of each light-emitting area, as shown in Figure 7(b). When one microlens 15 is shared by three or more light-emitting elements, and the centers of the light-emitting areas are not on a straight line, the center of gravity of the figure formed by connecting the centers of the light-emitting areas needs to be offset from the center of the microlens 15. In this case, the microlens may be cylindrical.

In addition, in this embodiment, the microlens 15 is shown to have a spherical surface in a cross section perpendicular to the main surface of the substrate 8, but the shape of the microlens 15 is not limited to this. For example, as shown in FIG. 8, the microlens 15 may be an aspherical lens in which the apex of the microlens 15 is offset from the center of the microlens 15 in the cross section. Even in this case, by using the configuration of this embodiment and arranging the light-emitting region and the microlens 15 so that they are offset, the light utilization efficiency of the optical system can be improved.

In this embodiment, the light-emitting device is described as being applied to an exposure system, but the light-emitting device is not limited to this. For example, the light-emitting device may also be a display device.

For example, in the case of a display device or display imaging device that uses a light-emitting device in a magnifying optical system as shown in Figure 2, the center of the functional area (display area) uses light rays that are directed in a frontal direction relative to the display surface. On the other hand, the periphery of the functional area uses light that is directed in an oblique direction relative to the display surface.

When the microlenses are positioned offset from the light-emitting area as shown in Figure 4(b), as in the configuration of this embodiment, the light is refracted as it passes through the microlenses, thereby improving the light emission intensity in a specific direction. Therefore, by using the configuration of this embodiment in the periphery of the functional area, it is possible to increase the light emission intensity of light directed in an oblique direction relative to the display surface. This makes it possible to provide a display device and a display/imaging device with improved light utilization efficiency.

(Embodiment 2)
The light emitting device of this embodiment will be described with reference to the drawings. In this embodiment, an example in which the light emitting device is applied as a display device will be described. Specifically, an example of a display device in which light emitted from the light emitting device is visually recognized through a magnifying optical system will be described. Note that the configuration of the light emitting device of this embodiment can be the same as that of the first embodiment, except that the amount of shifting of the microlenses is different. Therefore, a description of the overlapping parts will be omitted.

Figure 9(a) is a cross-sectional view showing one embodiment of a portion of a display device using the light-emitting device of this embodiment, and Figure 9(b) is a diagram illustrating the arrangement of the light-emitting element 100 and the microlens 15. Also, Figure 9(c) is a schematic plan view of a portion of a display device using the light-emitting device of this embodiment.

In this embodiment, in the center of the display area (functional area), the microlens 15 is positioned without any misalignment with the light-emitting area 17. That is, in the center of the display area, in a plan view of the surface of the substrate 8 on which the light-emitting elements 10 are arranged, the distance between the center of the microlens 15 and the center of the light-emitting area is essentially zero (including manufacturing errors). Also, because the cross-sectional shape of the microlens 15 here is spherical, the distance between the vertex of the microlens 15 and the center of the light-emitting area is also essentially zero (they coincide).

On the other hand, in the peripheral part of the display area, the microlenses 15 are arranged so as to be shifted outward relative to the light-emitting area 17. In other words, in the peripheral part of the display area, in a plan view of the surface of the substrate 8 on which the light-emitting elements 100 are arranged, the center of the microlenses 15 and the center of the light-emitting area are separated by a certain distance (they do not coincide). In addition, because the cross-sectional shape of the microlenses 15 here is spherical, the vertex of the microlenses 15 and the center of the light-emitting area are also separated by a certain distance.

In this embodiment, the pitch of the microlenses 15 (the distance between the centers of adjacent microlenses in a planar view relative to the surface of the substrate 8 on which the light-emitting elements 100 are arranged) is constant. The pitch of the light-emitting elements (the distance between the centers of the light-emitting regions of adjacent light-emitting elements 100 in the planar view) is also constant. However, the pitch of the microlenses 15 and the pitch of the light-emitting elements 100 are different. Therefore, even if the microlenses 15 and light-emitting elements 100 are arranged without any misalignment in the center, the microlenses 15 and light-emitting elements 100 will be arranged with a misalignment in the periphery.

Here, the display area (functional area) refers to the area on the substrate 8 where the light-emitting elements 100 are arranged, and drive circuits, pads, etc. may be arranged around the functional area.

A more specific configuration of the light-emitting device according to this embodiment will now be described. In the left peripheral portion of the display area, the microlenses 15 are arranged offset to the left (direction C) in Figure 9(a) relative to the light-emitting area, while in the light-emitting elements in the right peripheral portion of the display area, they are arranged offset to the right (direction D). As shown in Figure 9(b), at the center E' of the display area, the microlenses 15 and the center of the light-emitting area 17 are not offset.

On the other hand, in the adjacent pixel in the direction toward the peripheral part E of the display area, the microlens 15 is positioned at a distance 300a offset from the center of the light-emitting area 17. Furthermore, in the adjacent pixel in the direction toward the peripheral part A of the display area, the center of the microlens 15 is positioned at a distance 300b offset from the center of the light-emitting area 17. In other words, in the functional area, light-emitting elements with a smaller distance (offset) between the center of the light-emitting area and the center of the microlens are positioned closer to the center.

In the case of display devices, display imaging devices, etc., where light-emitting devices are used in magnifying optical systems, light rays directed in a frontal direction toward the display surface are used in the center of the functional area (display area). On the other hand, light directed in an oblique direction toward the display surface is used in the peripheral area of the functional area.

Therefore, with the configuration of this embodiment, the emission intensity of light passing through the microlenses 15 in a specific direction is improved in the peripheral area of the functional area. This makes it possible to increase the emission intensity of light directed obliquely toward the display surface in the peripheral area of the functional area. This makes it possible to provide a display device and a display/imaging device with improved light utilization efficiency.

For example, the display device of this embodiment has multiple sets of light-emitting regions and microlenses onto which light from the light-emitting regions is incident. In this case, the direction from the center of the light-emitting region to the vertex of the microlens in the multiple sets, parallel to the surface of the substrate 8 on which the light-emitting elements 100 are arranged, is the direction from the center to the periphery of the functional region in which the multiple sets are arranged. This makes it possible to increase the emission intensity of light passing through the microlenses 15 in the peripheral direction, i.e., light directed obliquely to the display surface, in the periphery of the functional region. Therefore, it is possible to provide a display device and a display/imaging device with improved light utilization efficiency.

In this embodiment, a full-color display can be achieved by configuring each light-emitting element to emit a different color. To achieve a full-color display, a method using white organic EL elements and color filters, as described above, can be used, or the light-emitting layer of each light-emitting element can be patterned to emit a different color.

Furthermore, full-color display can be achieved by varying the distance between the first and second reflecting surfaces for each light-emitting element. By varying the distance between the first and second reflecting surfaces, each light-emitting element can emit light of a different color while sharing the same light-emitting layer, making the manufacturing process for the light-emitting layer easier than with methods that pattern the light-emitting layer.

When arranging multiple light-emitting elements 100, the planar arrangement may be any of the following: stripe arrangement, square arrangement, delta arrangement, pentile arrangement, and Bayer arrangement. Figures 9(a) to 9(c) show an example of an arrangement in the case of a delta arrangement. The size and shape of the microlenses 15 may be set appropriately depending on the arrangement method. For example, in the case of a stripe arrangement, elongated microlenses may be arranged across multiple pixels as shown in Figure 7(a), or multiple hemispherical microlenses may be arranged within one pixel as shown in Figure 7(b).

In this embodiment, the color filter 18 may be disposed on the protective layer 14. The color filters 18a, 18b, and 18c may be color filters that transmit different colors, for example, color filters that transmit red, green, and blue light, respectively. In Figure 9(a), the color filter 18 is disposed between the protective layer 14 and the microlens 15.

As in embodiment 1, for pixels that emit light of the same color (e.g., green), the light-emitting device of this embodiment satisfies the following relationship for three pixels that are arranged adjacently in a planar view relative to the surface of the substrate 8 on which the light-emitting elements 100 are arranged: In this planar view, the distance X between the center of the light-emitting region and the vertex of the microlens is greater than the difference between the distance between the vertex of microlens 15a and the vertex 15b of the second microlens, and the distance between the vertex of microlens 15b and the vertex 15c of the microlens. In Figure 9(a), the pitch of the microlenses 15 is constant, so the center of the light-emitting region and the vertex of the microlens (the vertex in this case) are arranged with a misalignment.

This allows for increased light emission intensity in a specific direction, improving the light utilization efficiency in the optical system.

Note that while only pixels in which the microlens 15 corresponding to one pixel overlaps the center of the light-emitting area of that pixel in a planar view are shown, the light-emitting device is not limited to this. Pixels such as those shown in Figure 9(a) may be arranged throughout the entire functional area (display area). Furthermore, in the peripheral area of the functional area, pixels in which the microlens 15 corresponding to one pixel does not overlap the center of the light-emitting area of that pixel in a planar view may be arranged. This configuration improves the utilization efficiency of oblique light when it is desired to utilize light at a large angle (oblique light) from the center of the functional area toward the periphery in the peripheral area.

In this embodiment, an example has been shown in which full color display is possible using color filters that transmit three colors of light, but this is not limiting, and the color filters 18 may be omitted in part or in whole. Figure 10(a) shows a case in which the color filters are omitted. In this case, the light emitting device may be a white light emitting device, with the light emitting element 100 emitting white light. Furthermore, color display may be achieved by creating different light emitting layers in the light emitting element 100 and varying the color of light emitted from the light emitting element.

The stacking order of the color filters and microlenses may be selected as appropriate. Figure 9 shows an example in which the microlenses are located closer to the light extraction side than the color filters. By stacking them in this order, the only light that enters the microlenses is light that has passed through the color filters, which is preferable because it prevents unintended emission of colors emitted from adjacent pixels from leaving the element, improving display quality.

The distance between the center of the color filter 18 of each pixel and the center of the light-emitting region in a planar view (color filter offset amount) can be set as appropriate. Considering the optical path of light from the light-emitting region passing through the color filter 18 and reaching the microlens, it is preferable to set the color filter offset amount in the range of 0 or more and the microlens offset amount or less, as shown in Figure 9(a), as this is thought to be less likely to impede light transmission.

As shown in Figure 9(a), the color filters are formed integrally on the protective layer 14, and the microlenses may also be formed integrally, or may be formed on separate substrates and attached facing each other. By forming the color filters 18 and protective layer 14 integrally, the color filters can be formed with high positional accuracy relative to the light-emitting area using a photolithography process. Furthermore, by forming the color filters 18, microlenses 15, and protective layer 14 integrally, the positional relationship between the light-emitting area, color filters 18, and microlenses 15 can be formed with high precision.

In this embodiment, an example has been described in which the microlenses 15 are spherical microlenses, but the light-emitting device of this embodiment is not limited to this. For example, as shown in FIG. 11, aspherical lenses in which the center and vertex of the lens are offset may also be used. FIG. 11 shows an example in which, in the functional area of the display device, the microlenses 15 of the central pixel are spherical lenses, and the microlenses 15 of the surrounding (peripheral) pixels are aspherical lenses. In this case, too, by using the light-emitting device of this embodiment, it is possible to improve the emission intensity of light obliquely emitted from the pixels in the peripheral area. This makes it possible to improve the light utilization efficiency in the optical system.

Alternatively, as shown in FIG. 10(b), the microlens 15 may be formed on a separate substrate and then bonded to it. Creating the microlens 15 using a substrate separate from the substrate 8 carrying the light-emitting element 100 increases the degree of freedom in the processing method (temperature, etc.) used when creating the microlens 15, and therefore increases the degree of freedom in designing the microlens 15. Alternatively, as shown in FIG. 10(c), the microlens 15 and color filter 18 may be created on separate substrates and then bonded to the substrate 8 carrying the light-emitting element 100 to create a light-emitting device. This configuration increases the degree of freedom in designing the color filter 18 and microlens 15 when creating them.

In this case, as in embodiment 1, the microlenses 15 and color filters 15 are fixed to the substrate 8 with adhesive. Details are the same as in embodiment 1, so a detailed explanation will be omitted.

The above describes an example of a display device, but application examples of the light-emitting device of this embodiment are not limited to this. For example, the light-emitting device may be applied to an exposure system. A cross-sectional view of part of the light-emitting device of this embodiment's exposure system is similar to B-B' in Figure 10(a). An imaging lens array 3 is arranged on this, as shown in Figure 3(a). Furthermore, a schematic plan view of part of the functional area of the light-emitting device of Figure 10(a) is similar to Figure 10(c).

In this embodiment, the amount of microlens shift increases the further the light-emitting element is positioned from directly below the imaging lens array. The amount of microlens shift for each light-emitting element can be set according to the angle from each light-emitting element toward the imaging lens array. Therefore, by using this configuration in this embodiment, it is possible to improve light utilization efficiency, just like in embodiment 1.

(Embodiment 3)
[Configuration of organic light-emitting element]
The organic light-emitting element is provided by forming an anode, an organic compound layer, and a cathode on a substrate. A protective layer, a color filter, etc. may be provided on the cathode. When a color filter is provided, a planarizing layer may be provided between the protective layer and the color filter. The planarizing layer may be made of acrylic resin or the like.

[substrate]
Examples of the substrate include quartz, glass, a silicon wafer, a resin, and a metal. Furthermore, the substrate may be provided with a switching element such as a transistor and wiring, and an insulating layer thereon. Any material can be used for the insulating layer, as long as it allows for the formation of a contact hole to ensure electrical continuity between the anode 2 and the wiring, and ensures insulation from unconnected wiring. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[electrode]
A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

The material that makes up the anode should preferably have as high a work function as possible. For example, simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, or alloys combining these metals, can be used. Metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide can also be used. Furthermore, conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

One of these electrode materials may be used alone, or two or more may be used in combination. The anode may consist of a single layer or multiple layers.

When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates of these can be used. Furthermore, when used as a transparent electrode, transparent conductive oxide layers such as indium tin oxide (ITO) and indium zinc oxide can be used, but are not limited to these. Electrodes can be formed using photolithography techniques.

On the other hand, materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these. Alloys combining these metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials can be used alone or in combination. The cathode can have either a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to prevent silver aggregation. The alloy ratio is not important as long as silver aggregation can be prevented. For example, a 1:1 ratio is acceptable.

The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but DC and AC sputtering methods are preferred, as they provide good film coverage and are easy to use to reduce resistance.

[Protective layer]
A protective layer may be provided on the cathode. For example, by adhering glass provided with a moisture absorbent on the cathode, it is possible to prevent water and the like from penetrating into the organic compound layer and suppress the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to prevent water and the like from penetrating into the organic EL layer. For example, after forming the cathode, the device may be transported to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed by a CVD method to serve as a protective layer. A protective layer may be provided using atomic layer deposition (ALD) after the CVD film formation.

[Color filter]
A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on a separate substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using photolithography technology. The color filter may be made of a polymer.

[Planarization layer]
A planarizing layer may be provided between the color filter and the protective layer. The planarizing layer may be made of an organic compound, and may be either a low molecular weight or a high molecular weight, but is preferably a high molecular weight.

The planarization layer may be provided above or below the color filter, and may be made of the same or different materials. Specific examples include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin.

[Counter substrate]
A counter substrate may be provided on the planarization layer. The counter substrate is called a counter substrate because it is provided at a position corresponding to the aforementioned substrate. The counter substrate may be made of the same material as the aforementioned substrate.

[Organic layer]
The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light emitting element according to one embodiment are formed by the method shown below.

The organic compound layer constituting the organic light-emitting device according to one embodiment can be formed using dry processes such as vacuum deposition, ionization deposition, sputtering, and plasma. Instead of a dry process, a wet process can also be used in which the compound is dissolved in an appropriate solvent and a layer is formed using a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

Here, if a layer is formed using a vacuum deposition method or solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. Furthermore, when forming a film using a coating method, it is also possible to form a film by combining it with an appropriate binder resin.

Examples of the binder resin include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin. These are just examples, and the binder resin is not limited to these.

These binder resins may be used singly as homopolymers or copolymers, or as a mixture of two or more types. If necessary, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may also be used in combination.

[Use of light-emitting device]
The light-emitting device according to the first or second embodiment can be used as a display unit for various electronic devices, such as digital cameras, video cameras, head-mounted displays (goggle-type displays), game consoles, car navigation systems, personal computers, personal digital assistants, electronic books, and television sets. Specific examples are described below with reference to the drawings.

Figure 12 shows an example of an application of a semiconductor device as a display device. A display device using the light-emitting device according to the first or second embodiment can be applied to information display devices such as camera viewfinders, head-mounted displays, and smart glasses.

Figure 12(a) is a schematic diagram of an example used as a viewfinder for an imaging device such as a camera. Display light 217 and infrared light 218 are emitted from the display device 212, and the display light and infrared light pass through the same optical member 222 to reach the user's eyeball 216. The infrared light reflected by the user's eyeball 216 is converted into electrical information by an imaging device 223 having an imaging element, and the line of sight is detected based on this information. Instead of providing an imaging device, an imaging element may be provided on the insulating layer of the display device 1, and it may be used as a display imaging device.

Figure 12(b) shows an example of an imaging device such as a camera. The imaging device 224 has a viewfinder 225, a display 226, an operation unit 227, and a housing 228. The display device in Figure 12(a) is provided in the viewfinder 225.

In Figure 12(a), an example is shown in which the display light 217 and infrared light 218 pass through the same optical member 222, but separate optical members may be provided for the display light and infrared light. Furthermore, instead of providing an imaging device, an imaging element may be provided on the substrate of the display device 212 and used as a display imaging device. Detected line-of-sight information can be used to control the display device and various devices connected to the display device, such as for camera focus control, display image resolution control, and as a substitute for button operation.

In this embodiment, the display device having a light-emitting device may have an imaging device having a light-receiving element, and may control the image displayed on the display device based on user line-of-sight information from the imaging device.

Specifically, the display device determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and second field of view area may be determined by a control device of the display device, or may be received from an external control device. In the display area of the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

The display area also includes a first display area and a second display area different from the first display area, and a high priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be received from an external control device. The resolution of the high priority area may be controlled to be higher than the resolution of areas other than the high priority area. In other words, the resolution of areas with relatively low priority may be lowered.

Note that AI may be used to determine the first field of view area and high-priority areas. The AI may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from the image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI program may be included in the display device, the imaging device, or an external device. If included in an external device, it is transmitted to the display device via communication.

When display control is based on visual recognition detection, it is preferably applied to smart glasses that also have an imaging device that captures images of the outside world. The smart glasses can display captured external information in real time.

Alternatively, a system may include a first imaging device having a light-receiving element that receives infrared light, and a second imaging device having a light-receiving element different from that of the first imaging device for capturing images of the outside world, and control the imaging resolution of the second imaging device based on the user's line of sight information of the first imaging device. By lowering the imaging resolution of other areas compared to a prioritized area, the amount of information can be reduced, thereby reducing power consumption and display delays. The prioritized area may be the first imaging area, and an area with a lower priority than the first imaging area may be the second imaging area.

Figure 12(c) is a schematic diagram showing an example of smart glasses. An imaging and display device 229, typified by smart glasses, has a control unit 230, a transparent display unit 231, and an external imaging unit (not shown). When applied to smart glasses, both the display device and the external imaging device can be controlled based on detected gaze information, reducing power consumption and display delays. For example, by lowering the display and imaging resolution of areas of the display area other than the area the user is gazing at, the amount of information in both imaging and display can be reduced, reducing power consumption and display delays.

In addition, a display device having a light-emitting device according to the first or second embodiment can be used as a component of the display device or lighting device described below. Other applications include an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, and a light-emitting device with a white light source and a color filter.

The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, linear CCD, memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

The display unit of the imaging device or inkjet printer may also have a touch panel function. The driving method for this touch panel function is not particularly limited and may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method. The display device may also be used in the display unit of a multifunction printer.

Next, a display device according to this embodiment will be described with reference to the drawings. Figure 13 is a cross-sectional view showing an example of a display device having an organic light-emitting element and a TFT element connected to the organic light-emitting element. The TFT element is an example of an active element.

The display device 300 in Figure 13 has a substrate 301 made of glass or the like, and a moisture-proof film 302 on top of it to protect the TFT elements or organic compound layers. Also, reference numeral 303 denotes a metal gate electrode 303. Reference numeral 304 denotes a gate insulating film 304, and 305 denotes a semiconductor layer.

The TFT element 308 has a semiconductor layer 305, a drain electrode 306, and a source electrode 307. An insulating film 309 is provided on top of the TFT element 308. An anode 311 constituting the organic light-emitting element is connected to the source electrode 307 via a contact hole 310.

The electrical connection method between the electrodes (anode, cathode) included in the organic light-emitting element and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the form shown in Figure 13. In other words, it is sufficient that either the anode or cathode is electrically connected to either the source electrode or drain electrode of the TFT element.

In the display device 300 of Figure 13, the organic compound layer is illustrated as a single layer, but the organic compound layer 312 may be multiple layers. A first protective layer 314 and a second protective layer 315 are provided on the cathode 313 to prevent deterioration of the organic light-emitting element.

The display device 300 in Figure 13 uses transistors as switching elements, but MIM elements may alternatively be used as switching elements.

Furthermore, the transistors used in the display device 300 of Figure 13 are not limited to transistors using single-crystal silicon wafers, but may also be thin-film transistors having an active layer on the insulating surface of a substrate. Examples of active layers include single-crystal silicon, amorphous silicon, microcrystalline silicon, and other non-single-crystal silicon, as well as non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

The transistors included in the display device 300 of Figure 13 may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the substrate itself, such as a Si substrate, is processed to create the transistors. In other words, having a transistor within a substrate can also be seen as the substrate and transistor being formed integrally.

The light emission brightness of the organic light-emitting element according to this embodiment is controlled by a TFT, which is an example of a switching element. By arranging multiple organic light-emitting elements on a surface, an image can be displayed based on the respective light emission brightnesses. Note that the switching element according to this embodiment is not limited to a TFT, and may also be a transistor formed from low-temperature polysilicon, or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also be referred to as "within the substrate." Whether to provide a transistor within the substrate or to use a TFT is selected depending on the size of the display unit; for example, for a size of about 0.5 inches, it is preferable to arrange the organic light-emitting element on a Si substrate.

Figure 14 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different location even if the display device is a portable device.

The display device 1000 according to this embodiment may be used as a display unit of a photoelectric conversion device having an optical unit with multiple lenses and an image sensor that receives light that has passed through the optical unit. The photoelectric conversion device may have a display unit that displays information acquired by the image sensor. Alternatively, the display unit may acquire information using information acquired by the image sensor, and display information different from that information. The display unit may be a display unit exposed to the outside of the photoelectric conversion device, or a display unit located within the viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

Figure 15(a) is a schematic diagram showing an example of a photoelectric conversion device according to this embodiment. The photoelectric conversion device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may have the light-emitting device according to the first or second embodiment as a display device. In this case, the display device may display not only the image to be captured, but also environmental information, imaging instructions, etc. Environmental information may include the intensity of external light, the direction of external light, the speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, etc.

Since the optimum timing for capturing an image is very short, it is better to display information as quickly as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of the present invention. This is because organic light-emitting elements have a fast response speed. Display devices using organic light-emitting elements can be used more preferably than liquid crystal display devices, which require high display speed.

The photoelectric conversion device 1100 has an optical section (not shown). The optical section has multiple lenses that form an image on an image sensor housed in the housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

The display device according to this embodiment may have color filters having red, green, and blue colors. The red, green, and blue colors may be arranged in a delta array in the color filters.

The display device according to this embodiment may be used as a display unit for a mobile device. In this case, it may have both display and operation functions. Examples of mobile devices include mobile phones such as smartphones, tablets, and the head-mounted displays described above.

Figure 15(b) is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform operations such as unlocking. An electronic device having a communication unit can also be called a communication device. The display unit may have a light-emitting device according to the first or second embodiment.

Figure 16 is a schematic diagram showing an example of a display device having a light-emitting device according to this embodiment. Figure 16(a) shows a display device such as a television monitor or PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device according to the first or second embodiment may be used for the display unit 1302.

It has a frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in Figure 16(a). The bottom edge of the frame 1301 may also serve as the base.

Furthermore, the frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

Figure 16(b) is a schematic diagram showing another example of a display device having a light-emitting device according to the present embodiment. Display device 1310 in Figure 16(b) is configured to be bendable, and is a so-called foldable display device. Display device 1310 has first display unit 1311, second display unit 1312, housing 1313, and bending point 1314. First display unit 1311 and second display unit 1312 may have a semiconductor device according to the embodiment. First display unit 1311 and second display unit 1312 may be a single display device without any joints. First display unit 1311 and second display unit 1312 can be separated by bending point 1314. First display unit 1311 and second display unit 1312 may each display different images, or the first and second display units may display a single image.

Figure 17(a) is a schematic diagram showing an example of an illumination device according to this embodiment. The illumination device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion section 1405. The light source may have a light-emitting device according to the first or second embodiment. In this case, the image data input to each pixel may not form an image when displayed, but may be a signal corresponding to the same brightness.

The optical film 1404 may be a filter that improves the color rendering of the light source. The light diffusion section 1405 effectively diffuses the light from the light source, such as for lighting, and can deliver the light over a wide area. The optical filter and light diffusion section are transparent and may be provided on the light output side of the lighting. If necessary, a cover may be provided on the outermost surface.

The lighting device 1400 is, for example, a device that illuminates a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit to adjust the light intensity. The lighting device 1400 may have a light-emitting device according to the first or second embodiment, and may have, for example, an organic light-emitting element and a power supply circuit connected to it. The power supply circuit is a circuit that converts AC voltage to DC voltage. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

The lighting device 1400 according to this embodiment may also have a heat dissipation unit. The heat dissipation unit dissipates heat from within the device to the outside, and examples of such a unit include metals with high specific heat, liquid silicon, etc.

Figure 17(b) is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of lighting fixtures. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking, etc.

The tail lamp 1501 may have the light-emitting device according to the first or second embodiment as a lighting device. The tail lamp may have a protective member that protects the organic EL element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but it is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

The automobile 1500 may have a body 1503 and a window 1502 attached to it. The window may be a transparent display, as long as it is not a window for checking the front and rear of the automobile. The transparent display may have a light-emitting device according to the first or second embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting fixture attached to the body. The lighting fixture may emit light to indicate the position of the body. The lighting fixture has the light-emitting device according to the first or second embodiment as an illumination device.

As explained above, by using the light-emitting device according to the first or second embodiment, it is possible to provide a device with a wide viewing angle and improved light utilization efficiency.

2 Light-emitting device 8 Substrate 15 Lens 17 Light-emitting region 100 Light-emitting element

Claims (17)

a light emitting device having a first chip and a second chip on a main surface of a substrate, the first chip having only a set of a first light emitting element and a first lens overlapping in a plan view with a midpoint of a first light emitting region of the first light emitting element in a cross section perpendicular to the substrate, as a light emitting portion, and the second chip having only a set of a second light emitting element and a second lens overlapping in a plan view with a midpoint of a second light emitting region of the second light emitting element in a cross section perpendicular to the substrate ,
a vertex, which is a point of the first lens farthest from the substrate in a plan view, is spaced from a midpoint of the first light-emitting region in a positive direction in a first direction;
A light-emitting device characterized in that, in a planar view, the vertex, which is the point on the second lens that is farthest from the substrate , is away from the midpoint of the second light-emitting region in the negative direction in the first direction. In a plan view, a vertex of the first lens is spaced a first distance greater than 0 from a midpoint of the first light-emitting region,
2 . The light emitting device according to claim 1 , wherein, in a plan view, the vertex of the second lens is spaced from the midpoint of the second light emitting region by the first distance , which is greater than 0. the first chip further includes a third light-emitting element adjacent to the first light-emitting element in a second direction intersecting the first direction, and a third lens overlapping in plan view with a midpoint of a third light-emitting region of the third light-emitting element in a cross section perpendicular to the substrate ;
3. The light-emitting device according to claim 1, wherein, in a planar view, the vertex of the third lens , which is the point farthest from the substrate , is spaced apart in the first direction from the midpoint of the third light-emitting region in a cross section perpendicular to the substrate. 4. The light emitting device according to claim 3, wherein the vertex of the third lens is spaced a first distance greater than 0 from the midpoint of the third light emitting region. 4. The light emitting device according to claim 3, wherein the vertex of the third lens is spaced from the midpoint of the third light emitting region by a distance smaller than a first distance greater than 0. The light emitting device of claim 1, wherein the vertex of the first lens is the center of gravity of the outer shape of the first lens in the planar view. the first chip further includes a third light-emitting element adjacent to the first light-emitting element in a second direction intersecting the first direction, and a third lens overlapping in plan view with a midpoint of a third light-emitting region of the third light-emitting element in a cross section perpendicular to the substrate ;
3 . The light emitting device according to claim 1 , wherein, in a plan view, the vertex of the third lens is spaced apart from a midpoint of the third light emitting region in the second direction. In a plan view, a vertex of the first lens is spaced a first distance from a midpoint of the first light-emitting region,
8. The light emitting device according to claim 7, wherein, in a plan view, the vertex of the third lens is spaced the first distance from the midpoint of the third light emitting region. In a plan view, a vertex of the first lens is spaced a first distance from a midpoint of the first light-emitting region,
8. The light emitting device according to claim 7, wherein, in a plan view, the vertex of the third lens is spaced from the midpoint of the third light emitting region by a distance smaller than the first distance. an insulating layer is disposed on the first light emitting element;
10. The light emitting device according to claim 1, wherein the first lens is disposed in contact with the insulating layer. The light-emitting device described in any one of claims 1 to 10, characterized in that a color filter is disposed between the first light-emitting element and the first lens. The light-emitting device described in any one of claims 1 to 10, characterized in that a color filter is disposed on the first lens. The light-emitting device described in any one of claims 1 to 12, characterized in that the distance between the first light-emitting element and the first lens in a direction perpendicular to the main surface is 0.1 μm or more and 1 mm or less. A light-emitting device according to any one of claims 1 to 13, characterized in that it comprises a transistor connected to an electrode of the first light-emitting element. a lens array disposed above the first chip;
the lens array is disposed in the positive direction relative to the first chip, and
15. The light emitting device according to claim 1, wherein the lens array is disposed in the negative direction relative to the second chip. A light-emitting device comprising: the light-emitting device according to any one of claims 1 to 15; and a photoreceptor;
an exposure system configured so that light emitted from the light-emitting device is irradiated onto the photosensitive member; the light emitting device has a plurality of light emitting elements including the first light emitting element,
17. The exposure system according to claim 16, wherein the plurality of light emitting elements are arranged side by side in the rotation direction of the photosensitive member.