WO2022044708A1

WO2022044708A1 - Display device

Info

Publication number: WO2022044708A1
Application number: PCT/JP2021/028585
Authority: WO
Inventors: 昌哉玉置
Original assignee: 京セラ株式会社
Priority date: 2020-08-27
Filing date: 2021-08-02
Publication date: 2022-03-03

Abstract

This display device comprises: a cavity structure having a first surface as a display surface, the first surface having a recess; a first light emitting unit positioned in the recess to emit light of a first wavelength; a second light emitting unit positioned in the recess to emit light of a second wavelength shorter than the first wavelength; and a third light emitting unit positioned in the recess to emit light of a third wavelength shorter than the second wavelength. The first light emitting unit includes a first light emitting element for emitting light of the third wavelength, and a wavelength conversion member for converting the emitted light of the first light emitting element into light of the first wavelength.

Description

Display device

The present disclosure relates to a display device including a pixel having a light emitting element such as a light emitting diode (LED) element.

Conventionally, for example, the display device described in Patent Document 1 is known.

Japanese Unexamined Patent Publication No. 2006-119274

The display device of the present disclosure has a display surface, and a substrate provided with a recess on the display surface and a substrate.
A first light emitting unit located in the recess and emitting light of the first wavelength,
A second light emitting unit located in the recess and emitting light having a second wavelength shorter than the first wavelength.
A third light emitting unit located in the recess and emitting light having a third wavelength shorter than the second wavelength is provided.
The first light emitting unit includes a first light emitting element that emits light of the third wavelength, and a wavelength conversion member that converts the light of the third wavelength emitted from the first light emitting element into light of the first wavelength. , Have.

The purposes, features, and advantages of this disclosure will become clearer from the detailed description and drawings below.
It is a top view schematically showing the display device which concerns on one Embodiment of this disclosure. It is sectional drawing which cut at the cut plane line A1-A2 of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is a top view which shows typically the display device which concerns on other embodiment of this disclosure. It is sectional drawing which cut at the cut plane line A3-A4 of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is sectional drawing which shows typically the modification of the display device of FIG. It is a top view schematically showing the display device which concerns on still another Embodiment of this disclosure. It is a schematic plan view of the pixel for demonstrating the effect of the display device of this disclosure. It is a schematic plan view of the pixel for demonstrating the effect of the display device of this disclosure. It is a schematic plan view of the pixel for demonstrating the effect of the display device of this disclosure. It is a schematic plan view of the pixel for demonstrating the effect of the display device of this disclosure. It is a schematic plan view of the pixel for demonstrating the effect of the display device of this disclosure.

The configuration on which the display device of the present disclosure is based will be described. Patent Document 1 discloses a display device in which each pixel has a red LED element, a green LED element, and a blue LED element. The emission brightness of the LED element depends not only on the drive voltage applied to the LED element but also on the temperature of the LED element. In particular, among the red LED element, the green LED element, and the blue LED element, the red LED element that emits the longest wavelength light has a lower emission intensity as the temperature rises than the green LED element and the blue LED element. easy. Therefore, when the conventional display device is used for a long time, the red component in the displayed image is reduced, and as a result, the color reproducibility may be lowered or the display image may be uneven.

The decrease in color reproducibility and display unevenness of the display image caused by the temperature rise of the LED element can be reduced by correcting the drive current applied to the LED element. However, by adding a correction circuit for correcting the drive current to the display device, the power consumption of the display device may increase or the manufacturing cost of the display device may increase.

Hereinafter, the display device according to the embodiment of the present disclosure will be described with reference to the attached drawings. Each figure referred to below shows the main constituent members and the like of the display device which concerns on embodiment. The display device according to the embodiment may have a well-known configuration such as a circuit board, a wiring conductor, a control IC, and an LSI (not shown).

1 is a plan view schematically showing a display device according to an embodiment of the present disclosure, and FIG. 2 is a cross-sectional view taken along the cutting plane lines A1-A2 of FIG. 1, FIGS. 3 to 5. Is a cross-sectional view schematically showing a modified example of the display device of FIG. The cross-sectional views shown in FIGS. 3 to 5 correspond to the cross-sectional views shown in FIG.

As shown in FIGS. 1 and 2, the display device 1 of the present disclosure has a first surface 30a as a display surface, and is located in a substrate 30 having a recess 301 provided in the first surface 30a and a recess 301. A first light emitting unit 41 that emits light of the first wavelength, a second light emitting unit 42 that is located in the recess 301 and emits light of a second wavelength shorter than the first wavelength, and a second light emitting unit 42 that is located in the recess 301. A third light emitting unit 43 that emits light having a third wavelength shorter than the wavelength is provided, and the first light emitting unit 41 is from a first light emitting element 41a that emits light of the third wavelength and a first light emitting element 41a. It is configured to include a wavelength conversion member 41b that converts the emitted light of the third wavelength into the light of the first wavelength.

The above configuration has the following effects. Since it does not have a light emitting element that emits light of the first wavelength whose emission intensity tends to decrease due to a temperature rise, for example, a red light emitting element, the color reproducibility deteriorates and display unevenness caused by the temperature rise of the light emitting element. Can be suppressed. Further, since a correction circuit or the like for correcting the decrease in the emission intensity of the light emitting element due to the temperature rise by increasing the drive current is not required, the configuration can be simplified and the increase in the current consumption can be suppressed. .. Therefore, according to the display device of the present disclosure, it is possible to suppress an increase in power consumption and an increase in manufacturing cost.

The display device 1 according to the present embodiment includes a substrate (also referred to as a cavity structure) 30, a first light emitting unit 41, a second light emitting unit 42, and a third light emitting unit 43.

The cavity structure 30 has a plate-like or block-like shape. The cavity structure 30 has a first surface 30a and a second surface 30b opposite to the first surface 30a. The first surface 30a is a display surface on which the display device 1 emits image light. The cavity structure 30 may be in the shape of a plate-like body such as a substrate, a block-like body, a flexible sheet-like body, a three-dimensional structure having a curved surface, or the like.

A recess (also referred to as a cavity) 301 is provided on the first surface 30a. The recess 301 opens on the first surface 30a and is recessed in the thickness direction of the cavity structure 30. As shown in FIG. 2, for example, the recess 301 has an opening 301a and a bottom surface 301b on the first surface 30a, and an inner peripheral surface 301c connecting the opening 301a and the bottom surface 301b. The concave portion 301 may have a cross-sectional shape parallel to the first surface 30a, for example, a square shape, a rectangular shape, a circular shape, an elliptical shape, or the like, or may have another shape. Further, the recess 301 may have a shape in which the cross-sectional shape of the cross section parallel to the first surface 30a gradually shrinks in the direction from the first surface 30a to the second surface 30b. The recess 301 may have a shape in which the peripheral edge of the opening 301a surrounds the peripheral edge of the bottom surface 301b in a plan view.

The cavity structure 30 may be configured to include the first substrate 2 and the second substrate 3, for example, as shown in FIG.

The first substrate 2 has one main surface (also referred to as a third surface) 2a and the other main surface (also referred to as a fourth surface) 2b. The fourth surface 2b of the first substrate 2 may be the second surface 30b of the cavity structure 30. The shape of the first substrate 2 when viewed in a plan view (that is, when viewed from a direction perpendicular to the third surface 2a) is, for example, a triangle, a square, a rectangle, a trapezoid, a hexagon, a circle, an ellipse, or the like. It may have a shape or any other shape.

The first substrate 2 is made of, for example, a glass material, a ceramic material, a resin material, a metal material, a semiconductor material, or the like. Examples of the glass material used for the first substrate 2 include borosilicate glass, crystallized glass, quartz, soda glass and the like. Examples of the ceramic material used for the first substrate 2 include alumina (Al ₂ O ₃ ), aluminum nitride (AlN), silicon nitride (Si ₃ N ₄ ), zirconia (ZrO ₂ ), silicon carbide (SiC) and the like. Can be mentioned. Examples of the resin material used for the first substrate 2 include epoxy resin, polyimide resin, and polyamide resin. Examples of the metal material used for the first substrate 2 include aluminum (Al), titanium (Ti), beryllium (Be), magnesium (Mg) (particularly, high-purity magnesium having a purity of 99.95% or more), and zinc ( Zn), tin (Sn), copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), silver (Ag) and the like can be mentioned. The metal material used for the first substrate 2 may be an alloy material. Examples of the alloy material used for the first substrate 2 include iron alloys containing iron as a main component (Fe—Ni alloy, Fe—Ni—Co (cobalt) alloy, Fe—Cr alloy, Fe—Cr—Ni alloy). , Duralmin (Al-Cu alloy, Al-Cu-Mg alloy, Al-Zn-Mg-Cu alloy), which is an aluminum alloy containing aluminum as the main component, and magnesium alloy (Mg-Al alloy, Mg) containing magnesium as the main component. -Zn alloy, Mg-Al-Zn alloy), titanium boronized, Cu-Zn alloy and the like. Examples of the semiconductor material used for the first substrate 2 include silicon (Si), germanium (Ge), gallium arsenide (GaAs) and the like.

The first substrate 2 may have a single-layer structure composed of the above-mentioned glass material, ceramic material, resin material, metal material, semiconductor material, etc., or may have a multi-layer laminated structure. When the first substrate 2 has a laminated structure of a plurality of layers, the plurality of layers may be made of the same material or may be made of different materials.

The second substrate 3 is arranged on the third surface 2a of the first substrate 2, for example, as shown in FIG. The second substrate 3 has a plate-like or block-like shape. The second substrate 3 has a facing surface (also referred to as a fifth surface) 3a facing the third surface 2a of the first substrate 2 and an outer surface (also referred to as a sixth surface) 3b opposite to the fifth surface 3a. Have. The sixth surface 3b of the second substrate 3 may be the first surface 30a of the cavity structure 30. The shape of the second substrate 3 when viewed in a plan view may be, for example, a triangle, a square, a rectangle, a trapezoid, a hexagon, a circle, an ellipse, or the like, or any other shape. The first substrate 2 and the second substrate 3 may have the same plan-view shapes.

The second substrate 3 is formed with a through hole 31 penetrating from the fifth surface 3a to the sixth surface 3b. The through hole 31 exposes a portion (also referred to as a mounting portion) 2aa on the third surface 2a of the first substrate 2. The opening 31a on the sixth surface 3b of the through hole 31 may be the opening 301a of the recess 301, and the inner peripheral surface 31b of the through hole 31 may be the inner peripheral surface 301c of the recess 301. Further, the mounting portion 2aa may be the bottom surface 301b of the recess 301.

The second substrate 3 is made of a glass material, a ceramic material, a resin material, a metal material, a semiconductor material, or the like.

Examples of the glass material used for the second substrate 3 include borosilicate glass, crystallized glass, quartz, soda glass and the like. Examples of the ceramic material used for the second substrate 3 include alumina, aluminum nitride, silicon nitride, zirconia, silicon carbide and the like. Examples of the resin material used for the second substrate 3 include epoxy resin, polyimide resin, and polyamide resin. Examples of the metal material used for the second substrate 3 include aluminum, titanium, beryllium, magnesium (particularly, high-purity magnesium having a purity of 99.95% or more), zinc, tin, copper, iron, chromium, nickel, silver and the like. Can be mentioned. The metal material used for the second substrate 3 may be an alloy material. Examples of the alloy material used for the second substrate 3 include iron alloys containing iron as a main component (Fe—Ni alloy, Fe—Ni—Co alloy, Fe—Cr alloy, Fe—Cr—Ni alloy) and aluminum. Duralmin (Al-Cu alloy, Al-Cu-Mg alloy, Al-Zn-Mg-Cu alloy), which is an aluminum alloy as the main component, and magnesium alloy (Mg-Al alloy, Mg-Zn alloy) whose main component is magnesium. , Mg—Al—Zn alloy), titanium boronized, Cu—Zn alloy and the like. Examples of the semiconductor material used for the second substrate 3 include silicon, germanium, gallium arsenide and the like.

The second substrate 3 may have a single-layer structure made of the above-mentioned metal material, or may have a laminated structure of a plurality of layers. When the second substrate 3 has a laminated structure of a plurality of layers, the plurality of layers may be made of the same material or may be made of different materials. The through hole 31 may be formed by using, for example, a punching method, an electric casting method (plating method), a cutting method, a laser processing method, or the like. When the second substrate 3 is made of a metal material, the through hole 31 can be formed by using, for example, a punching method or an electroplating method. When the second substrate 3 is made of a semiconductor material, the through hole 31 can be formed by a photolithography method or the like including a dry etching step.

When the second substrate 3 is made of a metal material or a semiconductor material, an insulator or an insulating layer made of an electrically insulating material is provided between the third surface 2a of the first substrate 2 and the fifth surface 3a of the second substrate 3. It may be arranged. As a result, it is possible to prevent the electrodes, wiring conductors, and the like provided on the third surface 2a from being short-circuited with each other via the second substrate 3. Examples of the electrically insulating material used for the insulator or the insulating layer include silicon oxide and silicon nitride.

The first substrate 2 and the second substrate 3 may both be transparent substrates made of a transparent material such as a transparent resin material and a glass material. In this case, a transparent display device and a double-sided display type transparent display device can be manufactured. Further, the first substrate 2 and the second substrate 3 may both be flexible transparent substrates made of a transparent material such as a transparent resin material having flexibility. In this case, a flexible transparent display device and a double-sided display type transparent display device that can be installed on a non-flat surface such as a curved surface can be manufactured.

The first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43 are arranged in the recess 301. The first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43 arranged inside one recess 301 may constitute one pixel of the display device 1. The display device 1 may include a plurality of pixels, for example, as shown in FIG. Hereinafter, when it is not necessary to distinguish between the first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43, they are collectively referred to as the light emitting unit 4.

The first light emitting unit 41 emits light having the first wavelength λ1. The first wavelength λ1 may be a wavelength corresponding to red. The first wavelength λ1 may be, for example, a wavelength in the range of 620 to 750 nm. In the present specification, the “light of the first wavelength λ1” may mean monochromatic spectral light (monochromatic light) of the first wavelength λ1 and continuously spectral light having an intensity peak at the first wavelength λ1. It may mean. The same applies to "light having a second wavelength λ2" and "light having a third wavelength λ3" described later.

The first light emitting unit 41 includes a first light emitting element 41a and a wavelength conversion member 41b. When the drive current is supplied from the drive circuit, the first light emitting element 41a emits light having a third wavelength λ3 shorter than the first wavelength λ1. The first light emitting element 41a may be arranged on the bottom surface 301b of the recess 301. The wavelength conversion member 41b converts the light of the third wavelength λ3 emitted from the first light emitting element 41a into the light of the first wavelength λ1. The wavelength conversion member 41b covers at least the light emitting surface of the first light emitting element 41a. The light emitting surface may be the upper surface, or the upper surface and the side surface of the first light emitting element 41a. The wavelength conversion member 41b may be in contact with the first light emitting element 41a or may be separated from the first light emitting element 41a.

The first light emitting element 41a has a three-dimensional shape having an upper surface and side surfaces such as a cube, a rectangular parallelepiped, a columnar body, and a polygonal columnar body, and the wavelength conversion member 41b covers the upper surface and the side surface of the first light emitting element 41a. It may be configured to be present. In this case, in the first light emitting element 41a made of an LED element or the like, the upper surface and the side surface are often light emitting surfaces, and further, the lateral synchrotron radiation emitted from the side surface may include the maximum intensity light. be.

Further, the wavelength conversion member 41b is configured to cover the upper surface and the side surface of the first light emitting element 41a, and the thickness from the side surface of the portion covering the side surface of the first light emitting element 41a (in the direction orthogonal to the side surface). The thickness) may be thicker than the thickness from the upper surface of the portion covering the upper surface of the first light emitting element 41a (thickness in the direction orthogonal to the upper surface). In this case, when the lateral synchrotron radiation emitted from the side surface includes the maximum intensity light, the wavelength conversion of the maximum intensity light can be effectively performed without exception. The thickness from the side surface of the portion covering the side surface of the first light emitting element 41a may be about 2 μm to 80 μm, and the thickness from the upper surface of the portion covering the upper surface of the first light emitting element 41a is about 2 μm to 80 μm. It may be, but it is not limited to these values.

When the drive current is supplied from the drive circuit, the second light emitting unit 42 emits light having a second wavelength λ2 shorter than the first wavelength λ1. The second wavelength λ2 may be a wavelength corresponding to green light. The second wavelength λ2 may be, for example, a wavelength in the range of 500 to 570 nm. The second light emitting unit 42 may be configured to include a second light emitting element 42a that emits light having a second wavelength λ2. The second light emitting element 42a may be arranged on the bottom surface 301b of the recess 301.

When the drive current is supplied from the drive circuit, the third light emitting unit 43 emits light having a third wavelength λ3 shorter than the second wavelength λ2. The third wavelength λ3 may be a wavelength corresponding to blue light. The third wavelength λ3 may be, for example, a wavelength in the range of 450 to 500 nm. The third light emitting unit 43 may be configured to include a third light emitting element 43a that emits light having a third wavelength λ3. The third light emitting element 43a may be arranged on the bottom surface 301b of the recess 301. The third light emitting element 43a may be a light emitting element having the same light emitting characteristics as the first light emitting element 41a, or may be the same light emitting element as the first light emitting element 41a. Having the same emission characteristics may mean that the emission wavelengths are the same and the emission intensities for the same drive current are the same.

The first light emitting element 41a, the second light emitting element 42a, and the third light emitting element 43a may be self-luminous type light emitting elements. Hereinafter, when it is not necessary to distinguish between the first light emitting element 41a, the second light emitting element 42a, and the third light emitting element 43a, they are collectively referred to as a light emitting element 4a. Even if the light emitting element 4a is a self-luminous light emitting element such as a light emitting diode (Light Emitting Diode: LED) element, an organic light emitting diode (Organic Light Emitting Diode: OLED) element, or a semiconductor laser (Laser Diode: LD) element. good. In this embodiment, a light emitting diode element is used as the light emitting element 4a. The light emitting diode element is a two-terminal element having an anode terminal and a cathode terminal. The light emitting element 4a may be a micro light emitting diode element. The micro light emitting diode element has a rectangular plan view shape having a side length of about 1 μm or more and about 100 μm or less or about 5 μm or more and about 20 μm or less when mounted on the bottom surface 301b of the recess 301. May be good.

The wavelength conversion member 41b may contain a phosphor or quantum dots. Even if the wavelength conversion member 41b is composed of a main body portion made of a translucent insulating resin material or a translucent glass material, and a fluorescent substance or quantum dots dispersed in the main body portion. good. The fluorophore or quantum dots may be uniformly dispersed throughout the body.

Examples of the fluorescent material used for the fluorescent material of the wavelength conversion member 41b include organic fluorescent material such as cyanine-based dye, pyridine-based dye, and rhodamine-based dye, and (Sr, Ca) AlSiN ₃ : Eu, Y. Examples thereof include inorganic fluorescent material such as ₂ O ₂ S: Eu and Y ₂ O ₃ : Eu. In addition, "~: Eu" means that Eu is contained as a trace component. Quantum dots are particles having a diameter of about 1 nm or more and about 100 nm or less. Examples of the quantum dot material used for the quantum dots of the wavelength conversion member 41b include CdSe, CdS, InP and the like. When the wavelength conversion member 41b contains quantum dots, the color purity of the light of the first wavelength λ1 emitted from the wavelength conversion member 41b can be improved.

Examples of the insulating resin material used for the wavelength conversion member 41b include fluororesin, silicone resin, acrylic resin, epoxy resin and the like. Examples of the glass material used for the wavelength conversion member 41b include borosilicate glass, crystallized glass, quartz, soda glass and the like.

The display device 1 of the present embodiment is a first light emitting unit 41 that emits light having the longest wavelength (light of the first wavelength λ1) among the first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43. However, it is configured to include a first light emitting element 41a that emits light having a third wavelength λ3 shorter than the first wavelength λ1. Therefore, in the display device 1, the emission intensity due to the temperature rise of the first light emitting unit 41 is higher than that in the case where the first light emitting unit 41 includes a light emitting element that emits light having the first wavelength λ1. The decrease can be reduced. As a result, the display device 1 can suppress deterioration of color reproducibility and display unevenness of the displayed image due to the temperature rise of the light emitting unit 4 even when the display device 1 is used for a long time.

Further, according to the display device 1 of the present embodiment, it is possible to omit the circuit or function for compensating for the decrease in the emission intensity due to the temperature increase of the light emitting unit 4. As a result, it is possible to reduce the power consumption and cost of the display device.

Further, when the second light emitting unit 42 is configured by using the second light emitting element 42a and the third light emitting unit 43 is configured by using the first light emitting element 41a, the display device 1 has two types of light emitting elements (first light emitting element). It can be configured by using one light emitting element 41a and a second light emitting element 42a) and one kind of wavelength conversion member (wavelength conversion member 41b). Therefore, the number of processes for manufacturing the display device can be reduced, and the manufacturing process for the display device can be simplified. As a result, the manufacturing cost of the display device can be reduced, and the cost of the display device can be reduced.

As shown in FIG. 3, for example, the first light emitting unit 41 may be configured to include a first light emitting element 41a, a wavelength conversion member 41b, and a color filter 41c. The color filter 41c may transmit light having the first wavelength λ1 and suppress the transmission of light other than the light having the first wavelength λ1. That is, the color filter 41c may absorb and suppress light other than the light having the first wavelength λ1 so as not to be perceived by human visual sensation. As shown in FIG. 3, for example, the color filter 41c covers the first light emitting element 41a and the wavelength conversion member 41b. The color filter 41c may be in contact with the wavelength conversion member 41b covering the first light emitting element 41a, or may be separated from the first light emitting element 41a and the wavelength conversion member 41b.

The color filter 41c is made of a resin material to which a pigment or a dye is added. The pigment used in the color filter 41c may be an organic pigment or an inorganic pigment. Examples of the pigment used in the color filter 41c include an acrylic resin and a polycarbonate resin.

The color filter 41c can transmit the light whose wavelength is converted to the first wavelength λ1 by the wavelength conversion member 41b among the emitted light of the first light emitting element 41a. Further, the color filter 41c can absorb the light emitted from the first light emitting element 41a whose wavelength has not been converted to the first wavelength λ1 by the wavelength conversion member 41b. As described above, when the first light emitting unit 41 includes the color filter 41c, the color reproducibility of the first light emitting unit 41 can be improved, and by extension, the color reproducibility of the display device 1 can be improved.

The wavelength conversion member 41b and the color filter 41c are manufactured, for example, as follows. In order to manufacture the wavelength conversion member 41b, first, an insulating resin material or a glass material containing a phosphor or a quantum dot is subjected to a first light emitting unit by using a film forming technique such as a photolithography method or a screen printing method. A film is formed so as to cover 41. After that, the wavelength conversion member 41b can be manufactured by curing the formed insulating resin material or glass material by heating or irradiation with ultraviolet rays.

In order to produce the color filter 41c, first, a resin material to which a pigment or a dye is added is covered with a first light emitting unit 41 and a wavelength conversion member 41b by using a film forming technique such as a photolithography method or a screen printing method. To form a film. After that, the color filter 41c can be manufactured by curing the formed resin material by heating or irradiation with ultraviolet rays.

The wavelength conversion member 41b and the color filter 41c may be manufactured after the cavity structure 30 is manufactured, that is, after the first substrate 2 and the second substrate 3 are joined. The wavelength conversion member 41b and the color filter 41c may be manufactured before the cavity structure 30 is manufactured, that is, before the first substrate 2 and the second substrate 3 are joined.

Since the first light emitting unit 41 includes the first light emitting element 41a and the wavelength conversion member 41b, the second light emitting unit 42 having the second light emitting element 42a and not having the wavelength conversion member, and the first light emitting element. Compared with the third light emitting unit 43 which has 41a and does not have a wavelength conversion member, the efficiency of extracting light to the outside tends to decrease even if the same drive current is input. That is, the brightness of the first light emitting unit 41 is likely to decrease even if the same drive current is input, as compared with the second light emitting unit 42 and the third light emitting unit 43. Therefore, when the same brightness is obtained, the drive current (referred to as the first drive current) input to the first light emitting element 41a provided in the first light emitting unit 41 is transferred to the second light emitting element 42a provided in the second light emitting unit 42. It may be larger than each of the input drive current (referred to as the second drive current) and the drive current input to the first light emitting element 41a provided in the third light emitting unit 43 (referred to as the third drive current). The current value of the first drive current may be set to more than 1 times and not more than 3 times each of the current value of the second drive current and the current value of the third drive current, but is not limited to this range.

As shown in FIG. 1, for example, the cavity structure 30 has a first electrode (also referred to as an anode electrode) 7 and a second electrode (also referred to as a cathode electrode) 8. The anode electrode 7 and the cathode electrode 8 are arranged on the bottom surface 301b of the recess 301. In FIG. 2, the anode electrode 7 and the cathode electrode 8 are omitted. In the present embodiment, for example, as shown in FIG. 1, three

anode electrodes

7a, 7b, 7c and a cathode electrode 8 are provided on the bottom surface 301b of the recess 301. The anode terminal of the first light emitting element 41a, the anode terminal of the second light emitting element, and the anode terminal of the third light emitting element 43a are electrically connected to the three

anode electrodes

7a, 7b, and 7c, respectively. The cathode terminal of the first light emitting element 41a, the cathode terminal of the second light emitting element, and the cathode terminal of the third light emitting element 43a are electrically connected to the cathode electrode 8.

The first light emitting element 41a may be flip-chip connected to the anode electrode 7a and the cathode electrode 8 as shown in FIG. 1, for example. The second light emitting element 42a may be flip-chip connected to the anode electrode 7b and the cathode electrode 8. The third light emitting element 43a may be flip-chip connected to the anode electrode 7c and the cathode electrode 8. The light emitting element 4a and the anode electrode 7 and the cathode electrode 8 are connected by flip-chip connection using a conductive connecting member such as a solder ball, a metal bump, a conductive adhesive, and an anisotropic conductive film (ACF). , Electrically and mechanically connected. The connection between the light emitting element 4a and the anode electrode 7 and the cathode electrode 8 is not limited to the flip chip connection. The light emitting element 4a, the anode electrode 7, and the cathode electrode 8 may be electrically connected by using a conductive connecting member such as a bonding wire.

The light emitting element 4a does not have to be a connection form in which a flip chip connection (horizontal connection) is made to the anode electrode 7 and the cathode electrode 8, and may be a connection form in which a vertical connection is made. In the vertical connection, the light emitting element 4a having the cathode terminal located on the upper surface and the anode terminal located on the lower surface is mounted on the bottom surface 301b of the recess 301 in that state (vertically placed state), and the anode terminal is connected to the anode electrode 7. It is a connection form in which the cathode terminal is connected to the cathode electrode 8. In this case, the cathode electrode 8 may be a transparent electrode such as ITO (Indium Tin Oxide).

When the first substrate 2 is made of a metal material or a semiconductor material, an insulating layer made of silicon oxide, silicon nitride or the like is arranged on at least the third surface 2a of the first substrate 2, and the anode electrode 7 and the cathode are placed on the insulating layer. The electrode 8 may be arranged. As a result, when the light emitting element 4a is electrically connected to the anode electrode 7 and the cathode electrode 8, it is possible to prevent the anode terminal and the cathode terminal of the light emitting element 4a from being electrically short-circuited.

The anode electrode 7 and the cathode electrode 8 are connected to the drive circuit. The drive circuit can control light emission, non-light emission, light emission intensity, and the like of the light emitting element 4a. The drive circuit may be arranged, for example, on the third surface 2a of the first substrate 2 or may be arranged on the fourth surface 2b of the first substrate 2. The drive circuit may be arranged between layers of a plurality of insulating layers made of silicon oxide, silicon nitride, or the like, which are arranged on the third surface 2a or the fourth surface 2b.

The drive circuit includes a thin film transistor (TFT), a wiring conductor, and the like. The TFT may have, for example, a semiconductor film (also referred to as a channel) made of amorphous silicon (a-Si), low-Temperature Poly Silicon (LTPS), or the like. The TFT may have three terminals, a gate electrode, a source electrode, and a drain electrode. The TFT functions as a switching element that switches between conduction and non-conduction between the source electrode and the drain electrode according to the voltage applied to the gate electrode. The drive circuit may be formed by using a thin film forming method such as a chemical vapor deposition (CVD) method.

The drive circuit may be a semiconductor integrated circuit element such as an IC (Integrated Circuit) or an LSI (large Scale Integrated Circuit).

The display device 1 may be configured such that the light emitted from the light emitting element 4a is reflected at least once on the inner peripheral surface 301c of the recess 301. As a result, the light emitted from the inside of the recess 301 to the outside of the recess 301 can be brought close to the parallel light, so that the directivity of the image light emitted from the display device 1 can be improved. In order to reflect the emitted light of the light emitting element 4a at least once on the inner peripheral surface 301c, for example, the thickness of the second substrate 3 may be thicker than the thickness of the first substrate 2. That is, the depth of the through hole 31 may be increased. The display device 1 has, for example, the thickness of the second substrate 3, the shape of the recess 301 or the through hole 31, and the dimensions of the recess 301 or the through hole 31 and the light emitting element 4a based on, for example, the intensity distribution of the emitted light of the light emitting element 4a. By appropriately designing the ratio and the like, the emitted light of the light emitting element 4a may be configured to be reflected at least once on the inner peripheral surface 301c of the recess 301.

The recess 301 may have a depth that reflects light of the first wavelength, light of the second wavelength, and light of the third wavelength a plurality of times on the inner peripheral surface. It is possible to further improve the effect (convergence effect) of bringing the light emitted from the inside of the recess 301 to the outside of the recess 301 closer to the parallel light. The depth of the recess 301 may be about 3 to 10 times the height of the light emitting element 4a, or may be about 5 to 10 times, but is not limited to these ranges.

In the cavity structure 30, the inner peripheral surface 301c of the recess 301 may be a mirror surface. As a result, the reflectance of the emitted light of the light emitting element 4a on the inner peripheral surface 301c of the recess 301 can be increased, and the loss when the emitted light of the light emitting element 4a is reflected on the inner peripheral surface 301c can be reduced. As a result, it is possible to improve the efficiency of taking out the emitted light of the light emitting element 4a to the outside of the device, and it is possible to display a high-luminance image.

The inner peripheral surface 301c of the recess 301 may be mirror-finished, for example, by electric field polishing or chemical polishing. The surface roughness Ra of the inner peripheral surface 301c of the recess 301 may be, for example, about 0.01 μm or more and about 0.1 μm or less. The reflectance of the inner peripheral surface 301c of the recess 301 with respect to visible light may be, for example, about 85% or more and about 95% or less.

As shown in FIG. 4, for example, the display device 1 may include a light reflecting film 9 provided on the inner peripheral surface 301c of the recess 301. As a result, regardless of the material constituting the cavity structure 30, the surface roughness Ra of the inner peripheral surface 301c, etc., the reflectance of light in the recess 301 is increased, and the emitted light of the light emitting portion 4 is reflected in the recess 301. The loss can be reduced. As a result, the display device 1 can improve the efficiency of taking out the light emitted from the light emitting unit 4 to the outside of the device, and can display a high-luminance image.

The light reflecting film 9 may be made of, for example, a metal material. Examples of the metal material used for the light reflecting film 9 include aluminum, silver, and gold.

The light reflective film 9 may be formed on the inner peripheral surface 301c of the recess 301 by using a thin film forming method such as a CVD method, a vapor deposition method, or a plating method, and is a resin paste containing particles containing aluminum, silver, gold, and the like. It may be formed by using a film forming method such as a thick film forming method in which a film is fired and solidified. The light reflecting film 9 may be formed by a joining method in which a film containing aluminum, silver, gold, or the like or a film of the above alloy is joined to the inner peripheral surface 301c of the recess 301. The outer surface of the light-reflecting film 9 may be provided with a protective film for suppressing a decrease in reflectance due to oxidation of the light-reflecting film 9.

The first surface 30a of the cavity structure 30 may be roughened by blasting or the like. By roughening the first surface 30a, the surface area of the first surface 30a can be increased. As a result, the heat generated from the light emitting unit 4 is easily dissipated to the outside through the first surface 30a of the cavity structure 30. As a result, the display device 1 can suppress the deterioration of the color reproducibility and the display unevenness of the displayed image due to the temperature rise of the light emitting unit 4.

Further, by roughening the first surface 30a, the external light incident on the first surface 30a can be diffusely reflected on the first surface 30a. As a result, it is possible to suppress the reflected light of the external light from interfering with the image light emitted from the display device 1, and it is possible to suppress the deterioration of the display quality of the display device 1.

As shown in FIG. 4, for example, the display device 1 may include a light absorption film 10 arranged on the first surface 30a of the cavity structure 30. The light absorption film 10 can absorb external light incident on the first surface 30a. Since the display device 1 can reduce the reflection of the external light on the first surface 30a, it is possible to suppress the reflected light of the external light from interfering with the image light emitted from the display device 1. As a result, deterioration of the display quality of the display device 1 can be suppressed.

The light absorption film 10 may be formed, for example, by applying a photocurable or thermosetting resin material containing a light absorption material to the first surface 30a of the cavity structure 30 and curing it. The light absorbing material may be, for example, an inorganic pigment. The inorganic pigments include, for example, carbon-based pigments such as carbon black, nitride-based pigments such as titanium black, Cr-Fe-Co-based, Cu-Co-Mn (manganese) -based, Fe-Co-Mn-based, and Fe-Co. -A metal oxide pigment such as Ni—Cr may be used.

The light absorbing film 10 may have a concave-convex structure on its surface that absorbs incident light. For example, the light absorbing film 10 is a black film formed by mixing a black pigment such as carbon black into a base material such as a silicone resin, and has a structure in which an uneven structure is formed on the surface of the black film. May be good. In this case, the light absorption is significantly improved. The arithmetic average roughness of the uneven structure may be about 10 μm to 50 μm, or may be about 20 μm to 30 μm. The uneven structure may be formed by, for example, a transfer method.

The display device 1 may include a transparent body 11 as shown in FIG. 5, for example. The transparent body 11 is arranged in the recess 301 and seals the light emitting portion 4. The transparent body 11 may be in contact with the surface of the light emitting portion 4 and the inner peripheral surface 301c of the recess 301.

The transparent body 11 is made of a transparent resin material or the like. Examples of the transparent resin material used for the transparent body 11 include fluororesin, silicone resin, acrylic resin, polycarbonate resin, polymethylmethacrylate resin and the like.

When the transparent body 11 is arranged in the recess 301, the heat dissipation path (or heat transfer path) from the light emitting unit 4 to the cavity structure 30 is compared with the case where the recess 301 is filled with a gas such as air. ) Thermal resistance can be reduced. Therefore, the display device 1 can effectively dissipate the heat generated from the light emitting unit 4 to the outside through the cavity structure 30. As a result, the display device 1 can suppress the deterioration of the color reproducibility and the display unevenness of the displayed image due to the temperature rise of the light emitting unit 4.

Further, by having the transparent body 11, the display device 1 suppresses the position shift of the light emitting element 4a and the peeling of the light emitting element 4a from the mounting portion 2aa even when used for a long period of time. can. Therefore, according to the display device 1, the display device with improved long-term reliability can be obtained.

The transparent body 11 may be configured to have a main body portion made of a transparent resin material and a plurality of insulating particles dispersed inside the main body portion. Examples of the transparent resin material used for the main body include fluororesin, silicone resin, acrylic resin, polycarbonate resin, polymethylmethacrylate resin and the like. The insulating particles are made of, for example, a glass material, a ceramic material, or the like. Examples of the glass material used for the insulating particles include borosilicate glass, crystallized glass, quartz, soda glass and the like. Examples of the ceramic material used for the insulating particles include alumina, aluminum nitride, silicon nitride and the like. The insulating particles may be made of a glass material having a higher refractive index than that of the main body, or may be made of a ceramic material having a high light reflectance for visible light.

The insulating particles can scatter the external light incident on the transparent body 11 and reflect a part of the external light incident on the transparent body 11 toward the outside of the device. Therefore, the display device 1 can suppress the external light incident on the transparent body 11 from being reflected in the recess 301 and interfering with the emitted light of the light emitting unit 4. As a result, it is possible to suppress the external light from interfering with the image light emitted from the display device 1, and it is possible to suppress the deterioration of the display quality of the display device 1.

When the insulating particles are made of a transparent glass material or a transparent resin material, the insulating particles may be given a function as a color filter by coloring the insulating particles.

On the bottom surface 301b of the recess 301, the first light emitting unit 41 and the third light emitting unit 43 may be positioned symmetrically with respect to the second light emitting unit 42 in a plan view. This makes it possible to further reduce the display unevenness of the displayed image. The symmetric position may be a line symmetric position or a rotationally symmetric position. Further, in this case, the second light emitting unit 42 may be located at the center of the bottom surface 301b. This makes it possible to further reduce the display unevenness of the displayed image.

Further, when the shape of the bottom surface 301b in a plan view is a shape having a long axis and a short axis such as a rectangle or an ellipse, the first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43 are viewed in a plan view. The first light emitting unit 41 and the third light emitting unit 43 may be located on the long axis of the bottom surface 301b and are positioned symmetrically with respect to the second light emitting unit 42 in a plan view. This makes it possible to further reduce the display unevenness of the displayed image. Further, in this case, the second light emitting unit 42 may be located at the center of the bottom surface 301b. This makes it possible to further reduce the display unevenness of the displayed image.

On the bottom surface 301b of the recess 301, the first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43 may be configured to be located at each apex of an equilateral triangle in a plan view. This makes it possible to further reduce the display unevenness of the displayed image. In this case, the center of the equilateral triangle may be located at the center of the bottom surface 301b. This makes it possible to further reduce the display unevenness of the displayed image.

Next, the display device according to another embodiment of the present disclosure will be described. 6 is a plan view schematically showing a display device according to another embodiment of the present disclosure, and FIG. 7 is a cross-sectional view taken along the cutting plane line A3-A4 of FIG. 6, and FIGS. 8A to 8E. , 9 are cross-sectional views schematically showing a modified example of the display device of FIG. In FIG. 6, the light absorption film is omitted. In FIG. 7, the anode electrode and the cathode electrode are omitted. The cross-sectional views shown in FIGS. 8A to 8E and 9 correspond to the cross-sectional views shown in FIG. 7. In the following, the same reference numerals will be given to the configurations common to or similar to the configurations of the above embodiments, and detailed description thereof will be omitted.

In the display device 1A of the present embodiment, for example, as shown in FIGS. It may be composed of the second recess 304 and the second recess 304. That is, a wall portion (also referred to as a first wall portion) 302 located in the recess 301 is provided. The wall portion 302 divides the recess 301 into a first recess 303 in which the first light emitting portion 41 is located and a second recess 304 in which the second light emitting portion 42 and the third light emitting portion 43 are located. You may. As a result, it is possible to prevent the emitted light of the second light emitting unit 42 and the emitted light of the third light emitting unit 43 from being incident on the wavelength conversion member 41b of the first light emitting unit 41 and being converted into the light having the first wavelength λ1. can. As a result, the color reproducibility of the light emitting unit 4 can be improved, and by extension, the color reproducibility of the display device can be improved.

The wall portion 302 may be a member manufactured separately from the cavity structure 30, or may be a member integrally formed with the cavity structure 30.

When the wall portion 302 is made of a transparent material or a translucent material, it is on the side surface of the wall portion 302 facing the second light emitting portion 42 and the third light emitting portion 43, and on the side surface of the wall portion 302 facing the first light emitting portion 41. A light reflecting film may be provided on at least one of the above. As a result, it is possible to reduce the possibility that the emitted light of the second light emitting unit 42 and the emitted light of the third light emitting unit 43 pass through the wall portion 302 and enter the first recess 303 and enter the wavelength conversion member 41b. As a result, the color reproducibility of the light emitting unit 4 can be improved, and by extension, the color reproducibility of the display device can be improved.

The wavelength conversion member 41b of the display device 1A can be manufactured, for example, as follows. First, the cavity structure 30 in which the wall portion 302 is arranged in the recess 301 is manufactured, and the insulating resin material containing the phosphor or the quantum dot is made into an ink form. Next, the ink-shaped insulating resin material is discharged into the first recess 303 so as to cover the first light emitting element 41a by using inkjet technology. After that, the wavelength conversion member 41b as shown in FIGS. 7 and 8 can be manufactured by curing the insulating resin material by heating or irradiation with ultraviolet rays.

Further, the color filter 41c of the display device 1A can be manufactured, for example, as follows. First, the wavelength conversion member 41b is manufactured as described above, and the resin material to which the pigment or dye is added is made into an ink form. Next, the ink-shaped resin material is discharged into the first recess 303 so as to cover the first light emitting element 41a and the wavelength conversion member 41b by using inkjet technology. Then, by curing the resin material by heating or irradiation with ultraviolet rays, the color filter 41c as shown in FIG. 7 can be produced.

When the display device 1 includes the wall portion 302, the color filter 41c is a color filter prepared in advance using a resin material to which a pigment or a dye is added, in the first recess 303, for example, as shown in FIG. 8A. It may be produced by arranging.

FIG. 8B shows a configuration in which the upper surface of the first light emitting element 41a is in contact with the lower surface of the wavelength conversion member 41b in the configuration of FIG. 8A. A portion other than the upper surface of the first light emitting element 41a is embedded in a transparent body 41d made of a transparent resin material or the like. In the case of this configuration, it is possible to increase the number of portions of the wavelength conversion member 41b that contribute to wavelength conversion. That is, in the case of the configuration of FIG. 8A, the lower end portion of the wavelength conversion member 41b is a portion that does not easily contribute to the wavelength conversion, but in the case of the configuration of FIG. 8B, the entire wavelength conversion member 41b contributes to the wavelength conversion.

FIG. 8C is a configuration in which the transparent body 41d is inserted between the first substrate 2 and the second substrate 3 in the configuration of FIG. 8B. In this case, the transparent body 41d also functions as a fixing member for fixing the first substrate 2 and the second substrate 3, and the first substrate 2 and the second substrate 3 are firmly fixed.

FIG. 8D is a configuration in which the wavelength conversion member 41b is located above the first light emitting element 41a at a distance from the first light emitting element 41a in the configuration of FIG. 8B. The first light emitting element 41a is entirely embedded in the transparent body 41d. In this case, the same effect as in FIG. 8B is obtained.

FIG. 8E is a configuration in which the transparent body 41d is inserted between the first substrate 2 and the second substrate 3 in the configuration of FIG. 8D. In this case, the same effect as in FIG. 8C is obtained.

In the display device 1A, for example, as shown in FIG. 9, the recess 301 includes a first recess 303 in which the first light emitting unit 41 is located, a second recess in which the second light emitting unit 42 is located, and a third light emitting unit 43. It may be composed of a third recess located.

In other words, the second wall portion 305 located in the second recess 304 may be provided. Even if the second wall portion 305 divides the second recess 304 into a third recess 306 in which the second light emitting portion 42 is located and a fourth recess 307 in which the third light emitting portion 43 is located. good. That is, the second concave portion in which the second light emitting portion 42 is located may be referred to as the third concave portion 306, and the third concave portion in which the third light emitting portion 43 is located may be referred to as the fourth concave portion 307. As a result, the emitted light of the second light emitting unit 42 and the emitted light of the third light emitting unit 43 are incident on the wavelength conversion member 41b of the first light emitting unit 41 and are converted into the light of the first wavelength λ1. Can be suppressed. As a result, the color reproducibility of the light emitting unit 4 can be improved, and by extension, the color reproducibility of the display device can be improved.

As shown in FIG. 9, for example, the display device 1A may include a plurality of transparent bodies 11 arranged inside the first recess 303, the third recess 306, and the fourth recess 307, respectively. The plurality of transparent bodies 11 seal the first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43, respectively. The transparent body 11 that seals the first light emitting unit 41 is the first transparent body 11a, the transparent body 11 that seals the second light emitting unit 42 is the second transparent body 11b, and the transparent body 11 that seals the third light emitting unit 43 is transparent. Let the body 11 be the third transparent body 11c. As a result, the heat generated from the light emitting unit 4 can be effectively dissipated to the outside through the cavity structure 30, so that the color reproducibility deteriorates and the display image is uneven due to the temperature rise of the light emitting unit 4. Can be suppressed. Further, since it is possible to suppress the position shift of the light emitting element 4a and the peeling of the light emitting element 4a from the mounting portion 2aa, the display device with improved long-term reliability can be obtained.

The thickness of the first transparent body 11a may be thicker than the thickness of the wavelength conversion member 41b. In this case, the first transparent body 11a effectively functions as a light guide body and a heat transfer medium. That is, the directivity of the light of the first wavelength λ1 guided by the first transparent body 11a and radiated to the outside is improved, and the heat generated by the first light emitting unit 41 is transferred to the second transparent body 11a through the first transparent body 11a. It becomes easy to transmit to the substrate 3 and dissipate heat. Further, it is possible to effectively prevent the wavelength conversion member 41b from being exposed to air and causing deterioration such as oxidation. The second transparent body 11b and the third transparent body 11c are the same as those of the first transparent body 11a. The thickness of the first transparent body 11a may be about 5 μm to 300 μm, and the thickness of the wavelength conversion member 41b may be about 2 μm to 80 μm, but is not limited to these values.

When the display device 1A includes the first wall portion 302 and the second wall portion 305, the first recess 303, the third recess 306, and the fourth recess 307 can have substantially the same shape. As a result, the intensity distribution of the light emitted from the inside of the first recess 303 to the outside, the intensity distribution of the light emitted from the inside of the third recess 306 to the outside, and the intensity distribution of the light emitted from the inside of the fourth recess 307 to the outside are emitted. The intensity distributions of light can be brought closer to each other. As a result, it becomes possible to suppress display unevenness of the displayed image.

In the display device 1A of the present embodiment, each of the first recess 303, the third recess 306, and the fourth recess 307 can be recesses having a high aspect ratio. As a result, the emitted light of the first light emitting unit 41 is reflected at least once on the inner peripheral surface of the first recess 303, and the emitted light of the second light emitting unit 42 is reflected at least once on the inner peripheral surface of the third recess 306. , The emitted light of the third light emitting unit 43 can be reflected at least once on the inner peripheral surface of the fourth recess 307. As a result, it becomes possible to increase the directivity of the image light emitted from the display device. The aspect ratio of the recess may be the ratio D / L of the depth D of the recess to the absolute value L of the square root of the bottom area of the recess. The display device 1A may have a ratio D / L of about 2.5 or more. This makes it possible to effectively increase the directivity of the image light.

Next, the display device according to still another embodiment of the present disclosure will be described. FIG. 10 is a plan view schematically showing a display device according to still another embodiment of the present disclosure. In the following, the same reference numerals will be given to the configurations common to or similar to the configurations of the above embodiments, and detailed description thereof will be omitted.

The display device 1B of this embodiment is redundantly designed. In other words, the display device 1B arranges two first light emitting units 41 in the first recess 303, and two second light emitting units 42 and two second light emitting units 42 in the second recess 304, for example, as shown in FIG. The configuration is such that the three light emitting units 43 are arranged. As a result, for example, in the manufacturing process of the display device, when one of the two first light emitting units 41 is defective and becomes a non-light emitting state, the other can be driven, so that the manufacturing yield is improved. Can be made to.

As shown in FIG. 10, for example, the display device 1B has a configuration in which each of the two first light emitting units 41 includes a first light emitting element 41a and a wavelength conversion member 41b. As a result, the distance between the two adjacent light emitting units 4 becomes short, and even if the heat generated from the light emitting unit 4 is likely to be trapped in the pixel, the color reproducibility deteriorates due to the temperature rise of the light emitting unit 4. And the display unevenness of the display image can be suppressed. Further, in the display device 1B, since the first recess 303 and the second recess 304 are partitioned by the wall portion 302, even if the distance between the two adjacent light emitting portions 4 is shortened, the second recess is second. It is possible to reduce the possibility that the emitted light of the light emitting unit 42 and the emitted light of the third light emitting unit 43 are incident on the wavelength conversion member 41b. As a result, deterioration of the color reproducibility of the display device can be suppressed.

Each of FIGS. 11A to 11E is a schematic plan view of pixels for explaining the effect of the display device of the present disclosure. FIG. 11A shows a pixel 50a in which the first light emitting unit 41, the second light emitting unit 42, and the third light emitting unit 43 are located in one recess 301. FIG. 11B shows a pixel 50b in which the first light emitting unit 41 is located in the first recess 303, and the second light emitting unit 42 and the third light emitting unit 43 are located in the second recess 304. FIG. 11C shows a pixel 50c in which two first light emitting units 41 are located in the first recess 303, and two second light emitting units 42 and two third light emitting units 43 are located in the second recess 304. In FIG. 11D, the first light emitting portion 41 is located in the first concave portion 303, the second light emitting portion 42 is located in the third concave portion 306 (shown in FIG. 9) as the second concave portion, and the fourth light emitting portion 42 is located as the third concave portion. A pixel 50d in which the third light emitting unit 43 is located is shown in the recess 307 (shown in FIG. 9). In FIG. 11E, two first light emitting portions 41 are located in the first concave portion 303, two second light emitting portions 42 are located in the third concave portion 306 as the second concave portion, and the fourth concave portion 307 as the third concave portion. 2 shows a pixel 50d in which two third light emitting units 43 are located.

The display device of the present disclosure has a configuration in which the first light emitting unit 41 includes a first light emitting element 41a that emits light of a third wavelength and a wavelength conversion member 41b. For example, the first light emitting unit 41 has a configuration including a blue light emitting element 41a that emits blue light and a wavelength conversion member 41b that converts red light into blue light. Hereinafter, for easy explanation, the first light emitting unit 41 is a red light emitting unit 41, the second light emitting unit 42 is a green light emitting unit 42, the third light emitting unit 43 is a blue light emitting unit 43, and the second light emitting element 42a is green. The light emitting element 42a and the third light emitting element 43a are referred to as a blue light emitting element 43a.

In the above configuration (referred to as configuration A), when the blue light of the blue light emitting element 43a is mixed in the wavelength conversion member 41b, the excess blue light is wavelength-converted. Therefore, the blue light emitting element 41a and the blue light emitting element 43a may not be adjacent to each other or may be located in different recesses. Then, the configuration A has a pixel structure of

pixels

50a, 50b, and 50c. That is, it has a pixel structure having one wavelength conversion member 41b and one or two recesses. However, in the case of the configuration A, a pixel structure of

pixels

50d and 50e may be adopted.

On the other hand, for example, the red light emitting unit 41 has a blue light emitting element 41a and a wavelength conversion member 41b, and the green light emitting unit 42 has a blue light emitting element and a wavelength conversion member (wavelength) that converts blue light into green light. A configuration (referred to as a configuration B) having a conversion member (referred to as a conversion member 42b) is also conceivable. That is, all the light emitting units 4 are provided with a blue light emitting element. In this configuration B, in the case of the

pixels

50a, 50b, 50c, since the blue light emitting unit 43 and the green light emitting unit 42 are adjacent to each other, the emitted light of the blue light emitting element 43a of the blue light emitting unit 43 is the green light emitting unit 42. There is a problem that it is mixed in the wavelength conversion member 42b. Therefore, in the case of the configuration B, the pixel structure has

pixels

50d and 50e having two wavelength conversion members 41b and 42b and three recesses. From the above, the display device of the present disclosure also has an effect that the number of wavelength conversion members and recesses can be reduced.

However, in the configuration B, when the wavelength conversion member 42b of the green light emitting unit 42 covers the entire blue light emitting element and the entire wavelength conversion member 42b is covered by the color filter, the blue light from the adjacent blue light emitting element 43a. Since it is not affected by the above, the pixel structure of the

pixels

50a, 50b, 50c can also be taken.

As described above, the display device of the present disclosure can suppress a decrease in color reproducibility and display unevenness caused by an increase in the temperature of the LED element. Further, according to the display device of the present disclosure, it is possible to suppress an increase in power consumption and an increase in manufacturing cost.

Although each embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiment, and various changes, improvements, etc. are made without departing from the gist of the present disclosure. Is possible. Needless to say, all or part of each of the above embodiments can be combined as appropriate and within a consistent range.

The display device of this disclosure can be applied to various electronic devices. The electronic devices include automobile route guidance systems (car navigation systems), ship route guidance systems, aircraft route guidance systems, instrument indicators for vehicles such as automobiles, instrument panels, smartphone terminals, mobile phones, tablet terminals, and personals. Digital assistants (PDAs), video cameras, digital still cameras, electronic notebooks, electronic books, electronic dictionaries, personal computers, copying machines, game console terminals, televisions, product display tags, price display tags, industrial programmable displays. Equipment, car audio, digital audio players, facsimiles, printers, automated cash deposit and payment machines (ATMs), vending machines, medical displays, digital display watches, smart watches, guidance displays installed at stations and airports, etc. , Advertising signage (digital signage), etc.

1,1A, 1B Display device 2 First substrate 2a One main surface (third surface)
2aa part (mounting part)
2b The other main surface (fourth surface)
3 Second substrate 3a Facing surface (fifth surface)
3b outer surface (6th surface)
4 Light emitting unit 4a Light emitting element 41 First light emitting unit 41a First light emitting element 41b Wavelength conversion member 41c Color filter 41d Transparent body 42 Second light emitting unit 42a Second light emitting element 43 Third light emitting unit 43a Third

light emitting element

7,7a, 7b, 7c 1st electrode (anode electrode)
8 Second electrode (cathode electrode)
9 Light-reflecting film 10 Light-absorbing film 11 Transparent body 11a First transparent body 11b Second transparent body 11c Third transparent body 30 Substrate (cavity structure)
30a 1st surface 30b 2nd surface 31 Through hole 31a Opening 31b Inner peripheral surface 301 Recessed 301a Opening 301b Bottom surface 301c Inner peripheral surface 302 Wall part (1st wall part)
303 1st recess 304 2nd recess 305 2nd wall part 306 3rd recess 307 4th recess

Claims

A substrate having a display surface and having a recess on the display surface,
A first light emitting unit located in the recess and emitting light of the first wavelength,
A second light emitting unit located in the recess and emitting light having a second wavelength shorter than the first wavelength.
A third light emitting unit located in the recess and emitting light having a third wavelength shorter than the second wavelength is provided.
The first light emitting unit includes a first light emitting element that emits light of the third wavelength, and a wavelength conversion member that converts the light of the third wavelength emitted from the first light emitting element into light of the first wavelength. A display device having.
The first light emitting element has a three-dimensional shape having an upper surface and a side surface, and has a three-dimensional shape.
The display device according to claim 1, wherein the wavelength conversion member covers the upper surface and the side surface of the first light emitting element.
The display device according to claim 2, wherein the first light emitting element is a display device in which the lateral synchrotron radiation emitted from the side surface includes the maximum intensity light.
The wavelength conversion member claims that the thickness of the portion covering the side surface of the first light emitting element from the side surface is thicker than the thickness of the portion covering the upper surface of the first light emitting element from the upper surface. Item 3. The display device according to item 3.
The recess is any one of claims 1 to 4, which has a depth of reflecting each of the first wavelength light, the second wavelength light, and the third wavelength light on the inner peripheral surface a plurality of times. The display device described in.
The second light emitting unit has a second light emitting element that emits light of the second wavelength.
The display device according to any one of claims 1 to 5, wherein the third light emitting unit has the first light emitting element that emits light having the third wavelength.
Any of claims 1 to 6, wherein the first light emitting unit has a color filter that transmits light of the first wavelength emitted from the wavelength conversion member and suppresses transmission of light other than the light of the first wavelength. The display device according to item 1.
One of claims 1 to 7, wherein the recess is composed of a first recess in which the first light emitting portion is located, a second recess in which the second light emitting portion is located, and a second recess in which the third light emitting portion is located. The display device described in the section.
A first transparent body located in the first recess and sealing the first light emitting portion,
The display device according to claim 8, further comprising a second transparent body located in the second recess and sealing the second light emitting portion and the third light emitting portion.
The display device according to claim 9, wherein the first transparent body is thicker than the thickness of the wavelength conversion member.
A claim that the recess is composed of a first recess in which the first light emitting portion is located, a second recess in which the second light emitting portion is located, and a third recess in which the third light emitting portion is located. The display device according to any one of 1 to 7.
A first transparent body located in the first recess and sealing the first light emitting portion,
A second transparent body located in the second recess and sealing the second light emitting portion,
The display device according to claim 11, further comprising a third transparent body located in the third recess and sealing the third light emitting portion.
The display device according to claim 12, wherein the first transparent body is thicker than the thickness of the wavelength conversion member.
The display device according to any one of claims 1 to 13, wherein the wavelength conversion member contains a phosphor or quantum dots.
The display device according to any one of claims 1 to 14, wherein the light having the first wavelength is red light, the light having the second wavelength is green light, and the light having the third wavelength is blue light. ..
The display device according to any one of claims 1 to 12, wherein each of the first light emitting unit, the second light emitting unit, and the third light emitting unit includes a micro light emitting diode element.
The display device according to any one of claims 1 to 16, wherein the substrate is made of a transparent material.
The display device according to any one of claims 1 to 17, wherein the substrate has flexibility.