JP2002329895A - Light emitting device - Google Patents

Abstract

(57) [Summary] [Problem] It is possible to reduce the size and the use place is not limited.
To provide a light emitting device carrying a photocatalyst. SOLUTION: A light emitting chip which emits visible light is used, and a transparent resin containing titanium oxide carrying a spectral sensitizing dye is irradiated with visible light from the light emitting chip to activate the titanium oxide. did. This eliminates the need for an ultraviolet light source for activating the titanium oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-emitting device which can be used for a backlight of a liquid crystal, an illumination light source, various indicators, traffic lights, and the like. The present invention relates to a light emitting device having properties and antibacterial properties.

[0002]

2. Description of the Related Art In recent years, it has been proposed to support a light-emitting device with a photocatalyst and to impart antifouling properties, air purifying properties or deodorizing properties, antibacterial properties, etc. to the light-emitting devices by using the oxidation-reduction power of the photocatalyst. ing. When fine particles of titanium oxide as a photocatalyst are irradiated with light (ultraviolet light) having a band gap or more, electrons and holes are generated. These electrons and holes have very strong reducing power and oxidizing power, respectively, so that contaminants composed of organic substances and the like attached to the surface of the light emitting device are directly oxidized or generated by the generated holes. It can be decomposed by being oxidized by active oxygen species generated by a reaction between an electron and water or oxygen.

For example, Japanese Patent Application Laid-Open No. H10-41552 proposes an LED lamp having a coating layer containing titanium oxide on the surface of an envelope made of epoxy resin for sealing a light emitting chip. As an ultraviolet light source for activating titanium oxide, it has been proposed to provide an ultraviolet light generating element inside the envelope, or to arrange the ultraviolet light generating element between a large number of LED lamps arranged in a matrix. I have.

[0004] Also, Japanese Patent No. 3109472 discloses that
2. Description of the Related Art A light-emitting diode has been proposed in which a titanium oxide particle whose surface is covered with apatite and a phosphorescent member are provided on the surface of an exterior member for sealing a semiconductor chip, and sunlight or light from a fluorescent lamp or the like is used as an ultraviolet light source.

[0005]

However, in the method of providing an ultraviolet ray generating element as an ultraviolet ray source, a space for arranging the ultraviolet ray emitting element is required, so that it is difficult to reduce the size of the light emitting device. As a result, the use place of the light emitting device is limited. In addition, in the method using sunlight or light from a fluorescent lamp as an ultraviolet light source, titanium oxide cannot be activated at night or when the light is turned off, so that it takes a long time to decompose pollutants. There is also a problem that the use of the light emitting device is limited to a place where light can be sufficiently received.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a light-emitting device carrying a photocatalyst, which can be reduced in size and whose use place is not limited.

[0007]

In order to solve the above-mentioned problems, a light-emitting device according to the present invention comprises a light-transmitting resin in which titanium oxide carrying a spectral sensitizing dye is dispersed, and a method in which the titanium oxide is activated by visible light. And a light-emitting chip to be used.

The light-emitting device of the present invention uses a light-emitting chip that emits visible light as a light-emitting chip, and irradiates visible light from the light-emitting chip to a translucent resin containing titanium oxide carrying a spectral sensitizing dye. Since the titanium oxide is activated by this method, it is possible to decompose contaminants adhering to the air or to the surface of the translucent resin even without an ultraviolet light source.

Here, the spectral sensitizing dye plays a role described below. That is, when the spectral sensitizing dye is supported on titanium oxide particles and the spectral sensitizing dye is irradiated with visible light having a wavelength longer than 400 nm and including the absorption wavelength of the spectral sensitizing dye, the excited electrons of the spectral sensitizing dye are oxidized. Injected into the titanium particles, the titanium oxide can be activated. The activated titanium oxide can decompose contaminants attached to the surface of the light emitting device and contaminants in the air by its redox power.

A light emitting device according to the present invention includes a base having a reflective block forming a concave portion on an upper surface, a light emitting chip disposed in the concave portion and emitting visible light mounted on the base with a light emission observation surface as an upper surface. A light-emitting device having a light-transmitting resin and a sealing portion covering the light-emitting chip can be used. This makes it possible to provide a surface-mounted light-emitting device that carries a photocatalyst.

Further, the light emitting device of the present invention can use a light emitting resin in which a light transmitting resin is adhered to a light emitting chip. By attaching the translucent resin to the light emitting chip, the visible light emitted from the light emitting chip can be efficiently irradiated to the titanium oxide carrying the spectral sensitizing dye, thereby increasing the oxidation-reduction power of the titanium oxide. Can be.

Further, the light emitting device of the present invention can use a translucent resin containing activated carbon powder together with titanium oxide carrying a spectral sensitizing dye. Activated carbon powder has a large specific surface area of, for example, 1000 m ² / g or more, so that a high concentration of pollutants such as malodor can be adsorbed in a short time. When titanium oxide and activated carbon powder coexist,
The titanium oxide can decompose the contaminants adsorbed on the activated carbon powder, and the contaminants can be removed over a long period of time.

Further, in the light emitting device of the present invention, the sealing portion containing the light-transmitting resin is composed of a photocatalytic layer having a function of mainly decomposing contaminants and an adsorption layer for mainly adsorbing contaminants. With this configuration, the contaminants can be efficiently decomposed and removed. For example, the titanium oxide layer containing a light-transmitting resin containing titanium oxide is used as a photocatalytic layer, and the activated carbon layer made of a light-transmitting resin containing activated carbon powder laminated on the titanium oxide layer is used as an adsorption layer to form a sealing portion. Can be configured. According to this configuration, by providing the activated carbon layer on the titanium oxide layer that is in close contact with the light emitting chip, the titanium oxide layer can be irradiated with visible light without being hindered by the activated carbon powder. Since the activated carbon layer is exposed on the surface of the sealing portion, it is possible to quickly adsorb contaminants existing in the air around the light emitting device. Part of the contaminants adsorbed on the activated carbon is decomposed by the titanium oxide near the interface with the activated carbon layer, so that the adsorption ability of the activated carbon is not saturated. Thereby, a light emitting device having a high deodorizing ability can be obtained.

Further, a titanium oxide layer containing a light-transmitting resin containing titanium oxide is used as a photocatalytic layer, and an activated carbon layer made of a light-transmitting resin containing activated carbon powder is formed between the titanium oxide layer and the reflection block. May be used as an adsorption layer to form a sealing portion. Since the titanium oxide layer and the activated carbon layer are exposed on the surface of the sealing portion, the decomposition of the contaminant by the titanium oxide layer and the adsorption of the contaminant by the activated carbon layer can be performed at the same time. Can be decomposed and removed.

Further, in the light emitting device of the present invention, a fluororesin or a silicone resin can be used as the translucent resin.
By using a fluorine resin or a silicone resin having excellent oxidation resistance and light resistance, the resin is not decomposed by titanium oxide, so that only attached dirt can be decomposed.

Further, in the light emitting device of the present invention, the translucent resin may contain a phosphor that absorbs visible light from the light emitting chip and emits light having a wavelength longer than the visible light. Since color conversion can be performed based on the principle of light color mixing, mixed color light close to the absorption wavelength of the spectral sensitizing dye can be emitted, and titanium oxide can be efficiently activated.

In the light emitting device of the present invention, a light emitting chip that emits blue visible light can be used as a light emitting chip, and a YAG phosphor containing Ce can be used as a phosphor. A white light emitting device can be obtained by the principle of light color mixing. If this white light emitting device is used, for example, for office or home lighting, it becomes possible to remove pollutants from the air in a living room or work space.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 shows a light emitting device 1 according to the first embodiment.
FIG. 2 is a schematic sectional view showing the structure of No. 0. In the light emitting device 10, the insulating base 4 has a reflective block 6 forming a concave portion on the upper surface thereof, and a light emitting chip which emits visible light and has two opposing main surfaces, a light emission observing surface 1a and a mounting surface 1b. 1 is disposed in the recess with the light emission observation surface 1 a as the upper surface and mounted on the insulating base 4. The electrodes of the light emitting chip 1 are electrically connected to the electrodes 5 provided on the insulating base 4 by bonding wires 3. Light emitting chip 1
Is in close contact with the translucent sealing portion 2, and the sealing portion 2 contains titanium oxide particles 8 carrying a spectral sensitizing dye and a translucent resin 7 in which the titanium oxide particles 8 are dispersed. It is composed of a titanium oxide layer. The upper surface of the sealing portion 2 is formed so as to be substantially flush with the upper surface of the reflection block 6.
The reflection block 6 has a role of diffusing light emitted from the light emitting chip 1 to give uniform brightness, and
May be used as a single body, or may be formed separately and joined together.

In the first embodiment, since the sealing portion 2 is formed of the titanium oxide layer containing the titanium oxide particles 8 carrying the spectral sensitizing dye, the light emitted from the light emitting chip 1 absorbs the spectral sensitizing dye. Is irradiated to the sealing portion 2 so that excited electrons of the spectral sensitizing dye are injected into the titanium oxide to activate the titanium oxide, thereby contaminants adhering to the light emitting device and contamination in the air. The substance is decomposed by the titanium oxide. Since the titanium oxide is activated by the visible light emitted from the light emitting chip, an ultraviolet light source for activating the titanium oxide is not required. There is no need to provide a space for an ultraviolet light source, and the light emitting device can be made smaller. Further, since light such as sunlight or fluorescent light is not required, the use place is not limited.

A light emitting chip usable in the present embodiment is
Semiconductor that can efficiently emit visible light with high emission brightness
Nitride semiconductor (In)_xGa_yAl
_1-xyN, 0 ≦ x ≦ 1, 0 ≦ y ≦ 1) for the active layer.
Those used are preferably mentioned. Emitted from phosphor
Because it can emit light with a shorter wavelength than light,
A light emitting device with high exchange efficiency can be obtained. Nitride half
Light-emitting chips using conductors include sapphire substrates, spine
(MgAi ₂O₄) Substrate, SiC, GaN single crystal, etc.
Can be formed on the
For this purpose, it is preferable to use a sapphire substrate. That
In the present embodiment, the n-type and p-type nitride semiconductor layers
Is formed on a sapphire substrate, which is an insulating substrate,
A light emitting chip having both electrodes on the body layer side is used.

As the titanium oxide that can be used in the present embodiment, any of anatase-type titanium oxide and rutile-type titanium oxide can be used, but it is preferable to use anatase-type titanium oxide. This is because the anatase-type titanium oxide has a band gap of 3.2 eV, which is larger than the band gap of the rutile-type titanium oxide of 3.0 eV, and has a large oxidizing power and a large reducing power. The titanium oxide particles have a particle size of 5 nm to 100 nm, more preferably 10 nm to 100 nm.
nm to 50 nm. If it is less than 5 nm, it is difficult to disperse uniformly, and if it is more than 100 nm, the activity as a photocatalyst is not sufficient.

As the spectral sensitizing dye that can be used in the present embodiment, a metal complex or an organic dye having absorption in a visible light region of 400 nm or more can be used. Examples of the metal complex include metal phthalocyanines such as copper phthalocyanine and complexes of ruthenium, osmium and iron described in JP-A-5-504033. Examples of the organic dye include a cyanine dye, a merocyanine dye, an anthraquinone dye, an azo dye, a quinacdrine dye, and a metal-free phthalocyanine dye. Among the above-mentioned spectral sensitizing dyes, specifically, diaminoanthraquinonyl & dibabirtuyl isoindoline as dyes absorbing red,
Nanobromo-trichlorocopper phthalocyanine and dibabirtoline isoindoline can be suitably used as a dye that absorbs green, copper phthalocyanine and a ruthenium complex can be suitably used as a dye that absorbs blue. Here, the ruthenium complex is
Since it has absorption over the entire visible light range, it is possible to use a light emitting device or a blue light emitting chip and a phosphor in which light emitting chips emitting RGB (red, green, blue) capable of emitting white light are arranged close to each other. It can be used suitably for a combined light emitting device.
As a specific example of the ruthenium complex, Ru (2,2′-b
ipyridine-4,4'-dicarboxy
l) ₂ (SCN) ₂ .

To support the spectral sensitizing dye on titanium oxide, the titanium oxide particles are immersed in a solution in which the spectral sensitizing dye is dissolved, and preferably heated to adsorb the spectral sensitizing dye to the titanium oxide particles. It can be done by doing. The titanium oxide particles having the spectral sensitizing dye adsorbed thereon can be used after being separated from the solution, washed and dried.

The translucent resin for dispersing titanium oxide includes:
A light-emitting chip and those having high light resistance to light from a phosphor to be described later, having excellent translucency, having rigidity as a sealing material, and being stable against the oxidizing power of titanium oxide are preferable. . As the translucent resin, a fluororesin or a silicone resin can be suitably used. As the fluororesin, polytetrafluoroethylene resin, tetrafluoroethylene-ethylene copolymer resin, tetrafluoroethylene-
Hexafluoropropylene copolymer resin or vinyl fluoride resin can be used. The sealing unit 2 is, for example,
It can be formed by injecting a coating liquid containing titanium oxide particles and a light-transmitting resin into a concave portion of the light emitting device 10 and drying it.

In the light emitting device of this embodiment, the sealing portion may contain a phosphor. The phosphor that can be used is based on a cerium-activated yttrium / aluminum oxide phosphor that can emit light by exciting light emitted from a semiconductor light emitting chip having a nitride semiconductor as a light emitting layer. Things.

In order to obtain a white light emitting device, it is preferable to use a blue light emitting chip as a light emitting chip and use the above-mentioned yttrium / aluminum oxide-based phosphor as a phosphor. That is, when the blue light emitted from the blue light emitting chip enters the sealing portion containing the phosphor, a part of the blue light is absorbed by the phosphor in the sealing portion. The blue light absorbed by the phosphor acts as an excitation source, and the phosphor emits yellow fluorescence outside the sealing portion. On the other hand, the blue light that has not been absorbed by the phosphor in the sealing portion is directly emitted outside the sealing portion.
The yellow light and the blue light are mixed and appear to human eyes as white light. According to the principle of color mixing of light, light emitted from a blue light emitting chip is color-converted to obtain white light.

Specific yttrium / aluminum oxide phosphors include YAlO ₃ : Ce, Y ₃ Al ₅ O.
₁₂ Y: Ce (YAG: Ce) or Y ₄ Al ₂ O ₉ : C
e, and mixtures thereof. Ba, Sr, M for yttrium / aluminum oxide phosphor
At least one of g, Ca, and Zn may be contained. Further, by containing Si, the reaction of crystal growth can be suppressed, and the phosphor particles can be made uniform.

In the present specification, the yttrium / aluminum oxide-based phosphor activated with Ce is to be interpreted in a broad sense, and a part or the whole of yttrium is
It is substituted with at least one element selected from the group consisting of Lu, Sc, La, Gd and Sm, or a part or the whole of aluminum is substituted with any one or both of Ba, Tl, Ga and In to have a fluorescent action. It is used in a broad sense, including phosphors.

More specifically, the general formula (Y_zGd_1-z)
₃Al₅O₁₂: Ce (however, 0 <z ≦ 1)
Photoluminescent phosphors and general formulas (Re_1-aSm
_a) ₃Re ‘₅O₁₂: Ce (however, 0 ≦ a <1, 0 ≦
b ≦ 1, Re is selected from Y, Gd, La, Sc
At least one of Re 'is selected from Al, Ga, and In
Is at least one kind. Photoluminum indicated by)
It is a luminescent phosphor.

Since this phosphor has a garnet structure,
Resistant to heat, light and moisture, and has a peak in the excitation spectrum of 45
It can be set to around 0 nm. Also, the emission peak is near 580 nm and has a broad emission spectrum extending down to 700 nm.

The photoluminescent phosphor contains Gd (gadolinium) in the crystal, so that 460
It is possible to increase the excitation light emission efficiency in a long wavelength region of not less than nm. Due to the increase in the Gd content, the emission peak wavelength shifts to a longer wavelength, and the entire emission wavelength shifts to the longer wavelength side.
That is, when a reddish luminescent color is required, it can be achieved by increasing the replacement amount of Gd. On the other hand, as Gd increases, the emission luminance of photoluminescence due to blue light tends to decrease. Further, Tb, Cu, Ag, Au, Fe, Cr, Nd, Dy, C
o, Ni, Ti, Eu and the like can be contained.

In addition, in the composition of the yttrium-aluminum-garnet-based phosphor having a garnet structure, the emission wavelength shifts to the shorter wavelength side by partially replacing Al with Ga. Further, by substituting a part of Y in the composition with Gd, the emission wavelength shifts to the longer wavelength side.

When a part of Y is substituted with Gd, the substitution with Gd is less than 10%, and the content (substitution) of Ce is 0.0%.
It is preferable to set the value to 3 to 1.0. 2 substitutions with Gd
Below the percent, the green component is large and the red component is small,
By increasing the content of Ce, the red component can be supplemented, and a desired color tone can be obtained without lowering the luminance. With such a composition, the temperature characteristics are improved and the reliability of the light emitting chip can be improved. When a photoluminescent phosphor adjusted to have many red components is used in combination with a coloring pigment, a light emitting device capable of emitting an intermediate color such as pink can be formed.

[0034] Such a photoluminescent phosphor is
As a raw material of Y, Gd, Al, and Ce, an oxide or a compound that easily becomes an oxide at a high temperature is used, and the raw materials can be obtained by sufficiently mixing them in a stoichiometric ratio. Alternatively, a mixed material obtained by mixing a coprecipitated oxide obtained by calcining a solution obtained by dissolving a rare earth element of Y, Gd, and Ce in an acid at a stoichiometric ratio with oxalic acid and aluminum oxide and aluminum oxide Can be obtained. An appropriate amount of a fluoride such as barium fluoride or ammonium fluoride is mixed into a crucible as a flux, and baked in air at a temperature of 1350 to 1450 ° C. for 2 to 5 hours to obtain a baked product. The product is obtained by ball milling in water, washing, separating, drying and finally sieving.

In the light emitting chip, such a photoluminescent phosphor may be a mixture of two or more cerium-activated yttrium aluminum garnet phosphors and other phosphors.

Other phosphors capable of absorbing blue, blue-green or green to emit red light include sapphire (aluminum oxide) phosphor activated with Eu and / or Cr, and Eu.
And / or Cr-activated Ca-Al ₂ O ₃ activated with Cr
—SiO ₂ phosphor (oxynitride fluorescent glass) and the like. Using these phosphors, white light can also be obtained by mixing colors of light from the light emitting element and light from the phosphors.

In order to improve the luminous output, the phosphor used in the present invention has an average particle size of 10 μm to 50 μm.
m is preferable, and more preferably, 15 μm to 30 μm. Phosphors having such a particle size have high light absorption and conversion efficiency and a wide range of excitation wavelengths. As described above, by including a large-diameter phosphor having excellent optical characteristics, it becomes possible to satisfactorily convert light around the main wavelength of the light emitting element and emit light, thereby increasing the mass productivity of the light emitting device. Be improved.

It is preferable that the fluorescent material having the average particle size is contained frequently, and the frequency value is 20%.
% To 50% is preferred. By using a fluorescent substance having a small variation in particle diameter, color unevenness is suppressed and a light-emitting device having a favorable color tone can be obtained.

As specific phosphors, YAG phosphors activated with Ce (Y, Lu, Sc, La, Gd and Sm)
And a garnet-based phosphor that is activated with cerium and includes at least one element selected from the group consisting of Al, Ga, and In. YAG-based phosphors include Y, Gd, Ce
Of a rare earth element in an acid in a stoichiometric ratio is precipitated with oxalic acid. A co-precipitated oxide obtained by calcining this is mixed with aluminum oxide to obtain a mixed raw material. This was mixed with ammonium fluoride as a flux, packed in a crucible, and fired in air at 1400 ° C. for 170 minutes to obtain a fired product. The fired product can be ball-milled in water, washed, separated, dried, and finally passed through a sieve to form a YAG phosphor.

As another specific phosphor, nitrogen-containing CaO—Al ₂ O ₃ —SiO activated with Eu and / or Cr is used.
₂ phosphors. The nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ phosphor activated by Eu and / or Cr is:
A powder obtained by mixing a rare earth material at a predetermined ratio with a material such as aluminum oxide, yttrium oxide, silicon nitride, and calcium oxide in a nitrogen atmosphere at 1300 ° C. to 1900 ° C.
C. (more preferably from 1500.degree. C. to 1750.degree. C.) and molded. The molded article can be ball-milled, washed, separated, dried, and finally passed through a sieve to form the phosphor. Thereby, C excited by Eu and / or Cr capable of emitting red light emission by an excitation spectrum having a peak at 450 nm and blue light having a peak at about 650 nm.
It can be an a-Al-Si-ON-based oxynitride fluorescent glass.

In addition, C activated by Eu and / or Cr
By increasing or decreasing the nitrogen content of the a-Al-Si-ON-based oxynitride fluorescent glass, the peak of the emission spectrum can be continuously shifted from 575 nm to 690 nm. Similarly, the excitation spectrum can be shifted continuously. Therefore, white light can be emitted by combined light of a gallium nitride-based compound semiconductor containing GaN or InGaN doped with an impurity such as Mg or Zn in a light-emitting layer and light of a phosphor of about 580 nm.

In addition, the above-described YAG-based phosphor activated with Ce and the nitrogen-containing Ca-activated with Eu and / or Cr are used.
By combining with an Al-Si-ON-based oxynitride fluorescent glass, it is possible to form a light-emitting device having extremely high color rendering properties including a RGB component with high luminance by using a light-emitting chip capable of emitting blue light. . For this reason, an arbitrary intermediate color can be formed very simply by adding a desired pigment.

Embodiment 2 The light emitting device according to the present embodiment has the same structure as the light emitting device 10 of the first embodiment, except that activated carbon powder (not shown) is contained in the titanium oxide layer forming the sealing portion 2.

According to this embodiment, a light emitting device having a high deodorizing ability can be obtained. Activated carbon is, for example, 1000
Since it has a large specific surface area of at least m ² / g, it can adsorb high-concentration contaminants in a short time, and has a function as an adsorbent for contaminants. However, activated carbon has no function of decomposing contaminants, so when the amount of contaminants adsorbed reaches a saturated state, the adsorption speed decreases and the deodorizing ability decreases. In contrast, titanium oxide has a smaller specific surface area than activated carbon and therefore has a lower adsorption rate than activated carbon, but has a semi-permanent deodorizing ability because it can decompose pollutants. Therefore, by allowing titanium oxide and activated carbon to coexist, the titanium oxide can decompose the contaminants adsorbed on the activated carbon, so that the contaminants can be removed over a long period of time.

The activated carbon powder that can be used in the present embodiment has a specific surface area of 600 to 2000 m ² / g, more preferably 800 to 1200 m ² / g.

The sealing portion 2 is formed by injecting a coating liquid containing titanium oxide particles carrying a spectral sensitizing dye, activated carbon powder, and a light-transmitting resin into a concave portion of the light emitting device 10 and drying it. Can be formed. The coating liquid may be prepared by mixing titanium oxide particles carrying a spectral sensitizing dye and activated carbon powder using a ball mill or the like, or may be prepared using the method described below. That is, a solution in which a spectral sensitizing dye is dissolved is added to and mixed with titanium oxide sol, then, after adding activated carbon powder, the solvent is removed to prepare activated carbon powder supporting titanium oxide. The activated carbon powder supporting the titanium oxide is dispersed in a solution containing a translucent resin to prepare a coating liquid. According to this method,
Since the titanium oxide is supported on the activated carbon powder, the contaminants adsorbed on the activated carbon are quickly decomposed by the titanium oxide, and the deodorizing ability can be further improved.

Embodiment 3 FIG. 2 is a schematic sectional view showing the structure of the light emitting device 20 according to the present embodiment. A sealing portion 12 comprising a titanium oxide layer 13 which is in close contact with the light emitting chip 1;
Except for being constituted by an activated carbon layer 14 which is laminated on the titanium oxide layer 13 and contains the activated carbon powder 9 and the translucent resin 7.
The structure is the same as that of the light emitting device 10 of the first embodiment.

According to the present embodiment, the activated carbon layer 14 is formed so as to be exposed on the surface of the sealing portion 12.
Contaminants existing in the air around the light emitting device 20 can be quickly adsorbed. Furthermore, a part of the contaminants adsorbed on the activated carbon powder 9 is decomposed by the titanium oxide layer 13, so that the adsorption ability of the activated carbon powder 9 is not saturated. Thereby, the deodorization of the pollutant can be performed over a long period of time.

The same active powder as used in the second embodiment can be used. Further, as the light-transmitting resin in which the activated carbon powder is dispersed, it is preferable to use the fluororesin or the silicone resin used in Embodiment 1.

The sealing portion 12 can be formed, for example, by the following method. A coating solution containing a titanium oxide 8 carrying a spectral sensitizing dye and a translucent resin 7 is injected into the concave portion so as to cover the light emitting chip 1 and dried to form a titanium oxide layer 13 adhered to the light emitting chip 1. . Then, activated carbon powder 9
A coating solution containing the transparent resin 7 and the transparent resin 7 is injected onto the titanium oxide layer 13 and dried to form an activated carbon layer 14. Here, the thickness of the activated carbon layer is 50 μm to 300 μm, and more preferably 100 μm to 200 μm. If it is less than 50 μm, a sufficient deodorizing effect cannot be obtained. On the other hand, if it is larger than 300 μm, the light from the visible light emitting chip 1 is blocked by the activated carbon layer, and the luminance of the light emitting device is reduced.

In order to obtain uniform light emission, the phosphor may be contained in the titanium oxide layer or in the activated carbon layer.

Embodiment 4 FIG. FIG. 3 is a schematic sectional view showing the structure of the light emitting device 30 according to the present embodiment. A sealing portion 22 including a titanium oxide layer 23 that is in close contact with the light emitting chip 1;
The structure of the light emitting device 10 of the first embodiment is the same as that of the light emitting device 10 of the first embodiment, except that the light emitting device 10 is formed between the titanium oxide layer 23 and the reflection block 6 and includes an activated carbon layer 9 containing the activated carbon powder 9 and the translucent resin 7. is there.

According to the present embodiment, the titanium oxide layer 23
And the activated carbon layer 24 are formed substantially perpendicularly to the upper surface of the base 4 so that the titanium oxide layer 23 and the activated carbon layer 24 are exposed on the surface of the sealing portion 22. It is possible to simultaneously decompose the contaminants adhered to the surface and adsorb the contaminants by the activated carbon layer, and to efficiently decompose and remove the contaminants.

In order to obtain uniform light emission, the phosphor may be contained in the titanium oxide layer or in the activated carbon layer.

FIG. 4 is a schematic cross-sectional view showing an example of the manufacturing process of the light emitting chip according to the present embodiment. FIG. 4A shows a light emitting device 40 in which the light emitting chip 1 is mounted on the insulating substrate 4 and shows a state before a sealing portion is formed. First, the light emitting chip 1, the bonding wires 3 and the reflection block 6 are masked with a metal mask 41 (FIG. 4B).
Next, a coating solution containing the activated carbon powder 9 and the translucent resin 7 is injected into the voids not masked by the metal mask 41 in the concave portion 15 and dried, and dried.
Activated carbon layer 24 is formed between and reflective block 6 (FIG. 4c). The metal mask 41 is removed (FIG. 4d),
A coating liquid containing a titanium oxide 8 supporting a spectral sensitizing dye and a light-transmitting resin 7 is poured into the layer 5 and dried to form a titanium oxide layer 2.
3 (FIG. 4e). As a result, the sealing portion 22 including the titanium oxide layer 23 that is in close contact with the light emitting chip 1 and the activated carbon layer 24 formed between the titanium oxide layer 23 and the reflection block 6 can be formed. Of course, the phosphor may be contained in the titanium oxide layer or the activated carbon layer.

[0056]

As described above, the light emitting device of the present invention uses a light emitting chip that emits visible light as the light emitting chip,
Since the translucent resin contains titanium oxide carrying a spectral sensitizing dye and activates the titanium oxide by visible light from the light emitting chip, an ultraviolet light source for activating the titanium oxide becomes unnecessary. . Accordingly, it is possible to provide a light emitting device having antifouling properties, air purifying properties, deodorizing properties, antibacterial properties, etc., capable of being miniaturized, and having no limitation on the place of use.

In the light emitting device of the present invention, the light emitting chip is mounted on the base with the light emission observing surface as the upper surface, so that a surface mounted light emitting device having antifouling property, air purification property and the like can be provided.

In the light emitting device of the present invention, the transparent resin containing titanium oxide supporting the spectral sensitizing dye is made to adhere to the light emitting chip, so that the visible light emitted from the light emitting chip can be efficiently used. The titanium oxide supporting the spectral sensitizing dye can be irradiated well, and the titanium oxide can be more activated.

Further, in the light emitting device of the present invention, the translucent resin contains the activated carbon powder together with the titanium oxide particles carrying the spectral sensitizing dye, so that the contaminants adsorbed on the activated carbon powder can be removed by the titanium oxide. Can be decomposed, and contaminants can be removed over a long period of time.

Further, the light emitting device of the present invention uses a titanium oxide layer containing a light-transmitting resin containing titanium oxide particles as a photocatalytic layer, and a light-transmitting resin containing activated carbon powder laminated on the titanium oxide layer. Since the activated carbon layer is used as the adsorption layer, a part of the contaminants adsorbed on the activated carbon is decomposed by the titanium oxide near the interface with the activated carbon layer, and the adsorption ability of the activated carbon is not saturated. Thereby, the deodorizing ability can be improved.

Further, the light emitting device of the present invention uses a titanium oxide layer containing a light-transmitting resin containing titanium oxide particles as a photocatalytic layer, and contains activated carbon powder formed between the titanium oxide layer and the reflection block. Since the activated carbon layer of the translucent resin is used as the adsorption layer, the decomposition of the contaminants by the titanium oxide layer and the adsorption of the contaminants by the activated carbon layer can be performed simultaneously, and the decomposition and removal of the contaminants can be performed efficiently. it can.

Further, in the light emitting device of the present invention, since the fluororesin or the silicone resin is used as the translucent resin, the light emitting device is not decomposed by titanium oxide, and the life of the light emitting device can be improved.

Further, in the light emitting device of the present invention, since a phosphor is contained in the translucent resin, uniform color conversion can be performed and light emission without color unevenness can be obtained.

In the light emitting device of the present invention, a light emitting chip emitting blue light is used as the light emitting chip, and a YAG phosphor containing Ce is used as the phosphor. Thus, a white light-emitting device that can be used for the present invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating a structure of a light emitting device according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view illustrating a structure of a light emitting device according to a third embodiment of the present invention.

FIG. 3 is a schematic sectional view illustrating a structure of a light emitting device according to a fourth embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view illustrating a manufacturing process of a light emitting device according to a fourth embodiment of the present invention.

[Description of Signs] 1 nitride semiconductor light emitting chip, 1a light emission observation surface, 1b
Mounting surface, 2, 12, 22 sealing portion, 3 bonding wire, 4 insulating substrate, 5 electrodes, 6 reflection block, 7
Translucent resin, 8 titanium oxide supporting spectral sensitizing dye, 9 activated carbon powder, 10, 20, 30, 40 light emitting device, 13, 23 titanium oxide layer, 14, 24 activated carbon layer, 1
5 recess, 41 metal mask.

Continued on front page F-term (reference) 4G069 AA03 AA08 BA04A BA04B BA08A BA08B BA22A BA22B BA48A BB11B CA10 CA17 DA06 4H001 CC05 CC13 XA08 XA12 XA13 XA14 XA20 XA21 XA30 XA31 XA38 XA39 XA49 XA56 XA54 XA49 FF11

Claims (9)

[Claims] 1. A light-emitting device comprising: a light-transmitting resin containing titanium oxide carrying a spectral sensitizing dye; and a light-emitting chip for activating the titanium oxide with visible light. 2. The light emitting device according to claim 1, wherein the light emitting device includes: a base having a reflective block forming a concave portion on an upper surface; and a light emitting chip that is disposed in the concave portion and emits visible light mounted on the base with a light emission observation surface as an upper surface. 2. The light emitting device according to claim 1, further comprising: a sealing portion that covers the light emitting chip and is made of the translucent resin. 3. The light emitting device according to claim 1, wherein the light transmitting resin is in close contact with the light emitting chip. 4. The light emitting device according to claim 1, wherein the porous resin contains activated carbon powder together with the titanium oxide. 5. The method according to claim 1, comprising: a titanium oxide layer of a light-transmitting resin containing the titanium oxide; and an activated carbon layer of a light-transmitting resin containing activated carbon powder laminated on the titanium oxide layer. 3. The light emitting device according to any one of 3. 6. A titanium oxide layer of a translucent resin containing titanium oxide, and an activated carbon layer of a translucent resin containing activated carbon powder formed between the titanium oxide layer and the reflection block. The light emitting device according to claim 2 or 3, further comprising: 7. The light emitting device according to claim 1, wherein the translucent resin is a fluororesin or a silicone resin. 8. The method according to claim 1, wherein the translucent resin contains a phosphor that absorbs visible light from the light emitting chip and emits light having a wavelength longer than the visible light. A light-emitting device according to claim 1. 9. The light-emitting device according to claim 8, wherein the light-emitting chip is a light-emitting chip that emits blue visible light, and the phosphor is a YAG-based phosphor containing Ce.