JPH1187770A - Lighting appliance, reader, projector, purifier and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain lighting appliance using a light source device having a long life while easily reducing the size and weight by a simple constitution by including a fluorescent body absorbing ultraviolet rays emitted by a semicon ductor light emitting element and emitting secondary light having a wavelength longer than that of the ultraviolet rays. SOLUTION: Lighting appliance 100 has a wiring board 110 received inside a housing 120A and an envelope 120B. The housing 120A is a translucent cover, while the envelope 120B serves as a base attached to a ceiling or the like. Semiconductor devices 130, 130 emitting white light are placed on a principal surface of the wiring board 110. The semiconductor device 130 includes a light emitting diode and a fluorescent body for emitting ultraviolet rays. Such a semiconductor device 130 desirably has so-called 'three-wavelength-type' white light emission characteristics with a strength peak in each of wavelength regions of red, green and blue, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lighting device, a reading device, a projection device, a cleaning device, and a display device. More specifically, the present invention relates to a high-efficiency, long-life, compact and lightweight lighting device, a reading device, a projection device, a purification device, and a display device obtained by applying a semiconductor light emitting element that emits ultraviolet light to various forms. About.

[0002]

2. Description of the Related Art In various devices such as lighting devices, various types of light emitting devices used as light sources are employed. Among these conventional techniques, a typical one is a fluorescent lamp system.

FIG. 15 is a schematic diagram showing a schematic configuration of a conventional fluorescent lamp system. That is, the fluorescent lamp system 90
0 is constituted by a fluorescent lamp 910 and a power supply 920.
As the fluorescent lamp 910, a mixed gas 91 of mercury vapor and a rare gas such as argon (Ar) is provided inside a glass tube 911.
2 is sealed, and a fluorescent substance 91 is placed on the inner wall surface of the glass tube 911.
3 is generally applied. Such a fluorescent lamp 910 includes electrodes 915 and 91 provided at both ends.
5 is connected to a power supply 920 provided outside. The power supply 920 generates a high-frequency AC voltage, and when this voltage is applied, the mercury vapor causes a glow discharge to emit ultraviolet rays. The emitted ultraviolet light is absorbed by the fluorescent substance 913, is converted into a visible light, and is transmitted to the glass tube 911 to be emitted to the outside.

[0004]

However, in the conventional fluorescent lamp system as shown in FIG.
In order to generate a high-frequency voltage, a boosting and high-frequency generation circuit using an inverter or the like is required. For this reason, the configuration of the power supply 920 is complicated, the cost is high, the reliability is easily lowered, and the life is short.

In addition, since the fluorescent lamp 910 uses glow discharge of mercury vapor, there is a problem that a lighting time is delayed, and that the discharge is unstable immediately after lighting and the light amount is not stable. Furthermore, since the discharge state changes depending on the ambient temperature, there is a problem that the light amount tends to decrease particularly at a low temperature.

Further, since the fluorescent lamp 910 has a configuration in which mercury vapor is sealed in a glass tube, it is not easy to reduce the size and weight, the life is short, and the mechanical strength such as vibration and impact is sufficiently ensured. It was also difficult, and measures were needed to prevent environmental pollution from mercury.

On the other hand, another technique which has been widely used as a conventional technique is a light bulb.
However, even in a light bulb, since a configuration in which a heat filament is sealed inside a glass bulb, there are many points to be improved in many points such as power consumption, luminous efficiency, heat generation, life, mechanical strength, size and weight. There was a problem.

[0008] The present invention has been made in view of such a point. That is, the present invention is to provide a lighting device using a light source device having a very simple configuration, which can be easily reduced in size and weight, has a very stable emission wavelength and light amount, and has a very long life, and various other applied devices. Aim.

[0009]

That is, a lighting device according to the present invention comprises: a semiconductor light emitting element which emits ultraviolet light; and a semiconductor element which absorbs the ultraviolet light emitted by the semiconductor light emitting element and has a longer wavelength than the ultraviolet light. And a phosphor that emits the next light, and has many advantages such as high efficiency, long life, small size and light weight.

The lighting device according to the present invention is a wiring board, a plurality of semiconductor light emitting devices provided on the wiring board, and a light-transmitting enclosure provided to cover the periphery of the wiring board. A semiconductor light emitting device that emits ultraviolet light; and a fluorescent light that absorbs the ultraviolet light emitted by the semiconductor light emitting element and emits secondary light having a longer wavelength than the ultraviolet light. And has many advantages such as high efficiency, long life, small size and light weight.

Further, by making the semiconductor light emitting device a surface mount type, it is possible to make the device brighter and smaller.

Further, by forming a plurality of units in which a predetermined number of the semiconductor light emitting devices among the plurality of semiconductor light emitting devices are connected in series and connecting the plurality of units in parallel with each other, the reliability is improved. And the driving voltage can be suppressed.

On the other hand, a lighting device according to the present invention comprises a wiring board, a plurality of semiconductor light emitting elements provided on the wiring board for emitting ultraviolet light, and a light-transmitting member provided to cover the periphery of the wiring board. And an envelope having:
Even if a phosphor is provided on the inner wall surface of the envelope to absorb the ultraviolet light emitted by the semiconductor light emitting element and emit secondary light having a longer wavelength than the ultraviolet light, high efficiency can be achieved. Thus, many advantages such as long life, small size and light weight can be obtained.

Here, it is also possible to form a plurality of units formed by connecting a predetermined number of the semiconductor light emitting elements of the plurality of semiconductor light emitting elements in series, and connect the plurality of units in parallel with each other. The reliability can be improved and the driving voltage can be suppressed.

If the secondary light is visible light, a high-performance visible light source can be constructed.

Furthermore, if the visible light has intensity peaks in the red, green and blue wavelength regions, a so-called "three-wavelength" white light source can be constituted.

On the other hand, if a conversion circuit for converting a high-frequency voltage to a DC voltage is further provided so that the semiconductor light-emitting device can be driven by connecting to a power supply of a fluorescent lamp, compatibility with a conventional fluorescent lamp system can be obtained. It is very convenient.

On the other hand, a semiconductor light emitting device that emits ultraviolet light, a phosphor that absorbs the ultraviolet light emitted by the semiconductor light emitting device and emits secondary light having a wavelength in the visible light region, By providing a pulse generator that supplies a pulsed drive current, a lighting device as a flash device for a camera having many advantages such as high efficiency, long life, small size, and light weight can be configured.

Also, a semiconductor light emitting device that emits ultraviolet light, a phosphor that absorbs the ultraviolet light emitted by the semiconductor light emitting device and emits secondary light having a wavelength in the visible light region, and reflects the visible light By providing a concave mirror for irradiating in a predetermined direction, a lighting device as a lamp unit having many advantages such as high efficiency, long life, small size and light weight can be configured.

Further, a first light having wavelength selectivity between the semiconductor light emitting element and the phosphor, which transmits the ultraviolet light and reflects the secondary light emitted from the phosphor. By further providing the reflective film, the wavelength conversion efficiency can be improved. Further, on the side opposite to the semiconductor light emitting element viewed from the phosphor, reflects the ultraviolet light,
By further providing a second light reflection film having a wavelength selectivity such that the secondary light emitted from the phosphor is transmitted, the wavelength conversion efficiency can be further improved, and leakage of ultraviolet rays can be prevented.

A light absorber having a wavelength selectivity that absorbs the ultraviolet light and transmits the secondary light emitted from the phosphor is provided on a side opposite to the semiconductor light emitting element when viewed from the phosphor. By further providing, it is possible to prevent leakage of ultraviolet rays and to prevent unnecessary light emission due to disturbance light.

The semiconductor light emitting device can emit ultraviolet rays with high efficiency by including a gallium nitride based semiconductor in the light emitting layer.

The semiconductor light emitting device can emit ultraviolet light with higher efficiency by including boron, gallium and nitrogen in the light emitting layer.

As a specific configuration, a substrate, a first conductivity type GaN layer deposited on the substrate, a first conductivity type clad layer made of GaN containing aluminum,
It is desirable to have at least a light emitting layer made of GaN containing boron and a cladding layer of the second conductivity type made of GaN containing aluminum.

The emission wavelength is desirably about 330 nm.

The configuration described above with respect to the semiconductor light emitting element that emits ultraviolet light and the illumination device can be similarly applied to a reading device, a projection device, a purification device, and a display device to obtain the same effect. Can be.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention utilizes a semiconductor light emitting device which emits ultraviolet light and, if necessary, is combined with a material having a wavelength conversion function such as a phosphor, so that it is easy to reduce the size and weight of the device. An object of the present invention is to provide various applied devices such as a lighting device using a light source device having extremely stable light quantity and extremely long life.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a lighting device according to a first embodiment of the present invention. That is, FIG.
1 is an overall perspective view, FIG. 1 (b) is a cross-sectional view thereof, and FIG. 1 (c) is a schematic plan view of the wiring board.

The lighting device 100 according to the present embodiment has a configuration in which the wiring board 110 is housed inside the envelopes 120A and 120B. Enclosures 120A and 1
20B can be formed of, for example, a resin. The envelope 120A is a translucent cover, and the envelope 120B has a role as a base for attaching to a ceiling or the like.

On the main surface of the wiring board 110, semiconductor light emitting devices 130, 130,... Which emit white light are arranged. The semiconductor light emitting device 130 includes a light emitting diode (LE) that emits ultraviolet light, as described later in detail.
D) and a phosphor. Such a semiconductor light emitting device 1
For example, it is preferable that the light emitting element 30 has a so-called “three-wavelength type” white light emission characteristic having an intensity peak in each of red, green, and blue wavelength regions.

FIG. 2 is a schematic sectional view showing the structure of a semiconductor light emitting device suitable for use in the present invention. That is,
The semiconductor light emitting device 130 includes at least the semiconductor light emitting element 1
32 and a phosphor 136. Semiconductor light emitting device 13
2 is mounted on a mounting member 134 such as a lead frame. And the semiconductor light emitting element 13
The phosphor 136 is disposed on the second light extraction path. The semiconductor light emitting element 132 may be sealed with a resin 138, for example.

The semiconductor light emitting element 132 emits ultraviolet light, and the phosphor 136 absorbs the ultraviolet light, converts the wavelength, and emits visible light or infrared light having a predetermined wavelength to the outside.

The wavelength of light emitted from the phosphor can be adjusted by appropriately selecting the material of the phosphor. As a phosphor that absorbs ultraviolet light emitted from the semiconductor light emitting element 132 and efficiently emits secondary light, for example, as a phosphor that emits red light, Y ₂ O ₂ S: E
u, which emit blue light include (Sr, Ca,
Ba (Eu) ₁₀ (PO ₄ ) ₆ .Cl ₂ , which emits green light, includes 3 (Ba, Mg, Eu, Mn) O · 8
Al ₂ O _{3 and the} like can be mentioned. By mixing these fluorescent substances in an appropriate ratio, almost all colors in the visible light region can be expressed.

Further, these phosphors often have an absorption peak in a wavelength band around 330 nm. Therefore, in order to perform wavelength conversion efficiently with these fluorescent substances, it is desirable that the semiconductor light emitting element 132 emits ultraviolet rays in a wavelength band around 330 nm. Examples of the semiconductor light emitting device 132 having such characteristics include a device using GaN containing boron (B) as a light emitting layer, and a preferable configuration thereof will be described later in detail.

On the other hand, such a phosphor 136 may be disposed on the path of the emitted light away from the semiconductor light emitting device 132 or may be deposited on the surface of the semiconductor light emitting device 132. 132 may be arranged or contained.

Returning to FIG. 1 again, each semiconductor light emitting device 130 has a predetermined distance on the main surface of the wiring board 110 according to the required conditions such as the amount of illumination light, size, and power. It is arranged in. For compact and high-density mounting on the substrate 110, the semiconductor light emitting device 130
Preferably has a so-called “surface mount type (SMD)” lamp structure. By thus reducing the size of each light source, a light reflector or the like can be provided for each of the light sources to collect light from the light source, and a highly efficient and bright lighting device can be realized.

The connection relation between the semiconductor light emitting devices 130, 130,... Mounted on the substrate 110 is, for example, as shown in FIG. It is desirable to form a unit in which the elements 130 are connected in series, and connect the units in parallel. By adopting such a connection relationship, it is not necessary to set the power supply voltage or the driving current to an extremely high level, and even if one of the semiconductor light emitting devices 130 breaks down, it is given to another semiconductor light emitting device 130. It is possible to reduce the influence such as a change in the driving voltage. That is,
Even if one of the units fails, the remaining units can operate normally and the entire unit is not damaged unlike conventional fluorescent lamps, which is a significant advantage in terms of reliability. . However, the present invention is not limited to this, and all the semiconductor light emitting devices 130 on the wiring board 110 may be connected in series or in parallel.

Further, in the above-described example, the semiconductor light emitting device 130 that emits white light is employed, but the present invention is not limited to this. In addition, for example,
A semiconductor light emitting device that emits ultraviolet light is arranged on the wiring substrate 110, a phosphor is deposited on the inner wall surface of the resin cover 120A, the ultraviolet light is absorbed, the wavelength is converted, and white light is emitted to the outside. Is also good.

In order to ensure compatibility with a conventional fluorescent lamp, a conversion circuit for converting a high-frequency drive voltage applied to the fluorescent lamp into a DC voltage and supplying the DC voltage to the semiconductor light emitting device 130 is additionally provided. Extremely convenient. The lighting device according to the present embodiment can be used in a very wide range of fields, such as light sources for various manufacturing devices such as street lights, circulators, and mask aligners, and plant cultivation light sources, as well as indoor lights for homes and offices. Can be.

According to the estimation of the present inventor, in order to obtain the light amount corresponding to the conventional 40 W fluorescent lamp, for example, 66
The semiconductor light emitting devices 130 may be arranged in four rows. Advantageous Effects of Invention According to the present invention, power consumption is lower than conventional fluorescent lamps, the life is extremely long, miniaturization and weight reduction are easy, and mechanical strength against shock and vibration can be significantly improved. . In addition, environmental pollution due to mercury can be eliminated.

Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic view illustrating a flash device for a camera according to a second embodiment of the present invention. That is, the camera 150 shown in FIG.
4 together with a semiconductor light emitting device 130 according to the present invention as a so-called flash. Semiconductor light emitting device 130
Emits white light having a predetermined wavelength distribution by the semiconductor light emitting element and the phosphor as described above with reference to FIG.
Further, depending on the type of the phosphor 136 used in the semiconductor light emitting device 130, a specific emission wavelength can be emphasized, and in some cases, application to an infrared camera or the like is possible.
The semiconductor light emitting device 130 can be used as a flash by being connected to the pulse generator 158 and being supplied with a pulsed drive current.

According to the present invention, advantages such as low power consumption and extremely long life can be obtained as compared with a conventional flash device for a camera using a light bulb. Further, by utilizing the characteristics of the semiconductor light emitting element, it can be applied to a special use such as an ultra-high-speed photographing camera.

Next, a third embodiment of the present invention will be described. FIG. 4 is a schematic diagram illustrating a lamp according to a third embodiment of the present invention. That is, in the lamp unit 200 according to the present invention, the semiconductor light emitting device 130 is arranged near the focal point of the concave mirror 210. Inside the semiconductor light emitting device 130, ultraviolet light emitted from the semiconductor light emitting element is wavelength-converted by the phosphor and emitted to the outside as light such as white light. This light is reflected by the concave mirror 210
As a result, the light is collected and emitted in a predetermined direction. By arranging a fluorescent substance as a light source in the vicinity of the focal point of the concave mirror inside the semiconductor light emitting device 130, it is possible to improve the light collecting property.

The lamp unit 200 according to the present invention comprises:
For example, it can be applied to an in-vehicle headlamp or a flashlight. Semiconductor light emitting device 1 as shown in FIG.
30 is extremely easy to miniaturize as compared with a conventional light bulb. Therefore, the semiconductor light emitting device 1 having different emission colors
30 can be placed adjacent to the focal point of the concave mirror 210. As a result, one lamp 2
00 allows a plurality of emission colors to be realized. For example, a headlamp and a fog lamp can be incorporated in a common lamp unit. Also, a combination of a back lamp and a stop lamp can be made.

Further, instead of the semiconductor light emitting device 130,
A semiconductor light emitting element 132 that emits ultraviolet light may be arranged, and the ultraviolet light may be directly reflected by the concave mirror 210 and then subjected to wavelength conversion by a phosphor. In this case, the phosphor is
For example, it may be deposited on the reflecting surface of the concave mirror 210 or may be arranged at the light exit window of the lamp unit.

According to the present invention, as compared with a lamp unit using a conventional light bulb, the power consumption is small, the life is extremely long, and the mechanical strength against vibration and impact is remarkably improved. Is obtained. further,
Since the size of the light source can be reduced, the light-collecting property can be dramatically improved, which is particularly advantageous when illuminating a distant place with high illuminance is desired.

Next, a fourth embodiment of the present invention will be described. FIG. 5 is a schematic diagram illustrating a reading device according to the fourth embodiment of the present invention. That is, in the reading device 250 according to the present invention, the semiconductor light emitting device 130A that emits red light, the semiconductor light emitting device 130B that emits green light, and the semiconductor light emitting device 130C that emits blue light are arranged. ing. The semiconductor light emitting devices 130A, 130B, and 130C each have a built-in phosphor 136.
By changing the material of the above, each emission color can be obtained.

The red light, green light, and blue light from the semiconductor light emitting devices 130A, 130B, and 130C are emitted toward a document (not shown), and the respective reflected lights are detected by the light receiving units 260A, 260B, and 260C. Has been. Light receiving section 260A,
B and C can be composed of, for example, a photosensitive element or a CCD. The reading apparatus according to the present invention is incorporated in a facsimile (FAX), a scanner, a copying machine, or the like, and can read a predetermined document and convert it into an electric signal.

According to the present invention, as compared with the conventional reading apparatus using a fluorescent lamp, the power consumption is small, the life is extremely long, and the mechanical strength against vibration and impact is remarkably improved. Is obtained.

Next, a fifth embodiment of the present invention will be described. FIG. 6 is a schematic diagram illustrating a projection device according to a fifth embodiment of the present invention. That is, in the projection device 300 according to the present invention, the semiconductor light emitting device 130 is disposed near the focal point of the concave mirror 310, and the projection lens 320 is disposed in front of the semiconductor light emitting device 130. Light emitted from the semiconductor light emitting device 130 is condensed by the concave mirror 310, and the transmission pattern of a predetermined document 340 drawn on a translucent sheet or the like is projected on the screen 342 by the projection lens 320.

According to the present invention, power consumption is small, heat generation is small, the life is extremely long, and miniaturization and weight reduction are easy, as compared with a conventional reading apparatus using a light bulb.
The advantage is obtained that the mechanical strength against vibration and impact is significantly improved.

Next, a sixth embodiment of the present invention will be described. FIG. 7 is a schematic diagram illustrating a purification device according to a sixth embodiment of the present invention. That is, in the purification device 350 according to the present invention, the ozone generator 370 and the semiconductor light emitting element 132 are arranged along the purification circuit 360. When water 355A is supplied to the purification circuit 360, the water 355A is sterilized and purified by ultraviolet rays from the semiconductor light emitting element 132 and is discharged as purified water 355B. Further, if ozone is dissolved in water by the ozone generator 370 before the ultraviolet irradiation, in addition to the sterilizing / purifying effect of the gen-zhong, the activation of active oxygen by ultraviolet irradiation is promoted, and the sterilizing / purifying effect is further enhanced.

On the other hand, the purifying device 350 according to the present invention is also suitable for purifying air. That is, by supplying air to the purification circuit 360, the semiconductor light emitting element 132
Irradiation of ultraviolet rays from the air can sterilize and purify the air. Further, a purifying device having a higher sterilizing effect may be provided by raising the temperature of the supplied air and exhausting it as hot air by a heating mechanism (not shown). The purifying device 350 according to the present invention can also be applied to sterilization / purification for medical use, various storage cases, refrigerators, and the like.

According to the present invention, as compared with a conventional purifying apparatus using an ultraviolet fluorescent lamp, the intensity of ultraviolet light is high, the purifying ability is high, the power consumption is small, the life is extremely long, and vibration, impact, etc. The advantage is that the mechanical strength is significantly improved. Further, a predetermined stable output can be obtained instantaneously immediately after the semiconductor light emitting element 132 is turned on. Furthermore, since the whole apparatus can be miniaturized, installation becomes easy, which is particularly advantageous for uses such as aquarium for aquarium fish and purification of bath water for home use.

Next, a seventh embodiment of the present invention will be described. FIG. 8 is a schematic diagram illustrating an ultraviolet irradiation device according to a seventh embodiment of the present invention. That is, in the ultraviolet irradiation device 400 according to the present invention, the semiconductor light emitting element 132 is arranged near the focal point of the concave mirror 410. The ultraviolet light emitted from the semiconductor light emitting device 132 is
The light is reflected and condensed by 0, and irradiates the target 440 with high irradiation intensity. Thus, for example, it can be applied to uses such as resin molding, tanning, and disinfection. In addition, if a BGaN-based semiconductor light emitting device described later is used, 300 nm is useful for generating vitamin D in the human body.
Because it can generate nearby ultraviolet rays with high efficiency,
Application as a health appliance is also possible.

According to the present invention, as compared with a conventional ultraviolet irradiation apparatus using an ultraviolet fluorescent lamp, the intensity of the ultraviolet light is high, the power consumption is small, the life is extremely long, and the mechanical strength against vibration and shock is high. The advantage is obtained that the strength is significantly improved. Furthermore, according to the present invention,
Since the light source can be made extremely small, the light condensing property can be increased and the ultraviolet irradiation density can be dramatically increased.

Next, an eighth embodiment of the present invention will be described. FIG. 9 is a schematic diagram illustrating a display device according to the eighth embodiment of the present invention. That is, the display device 450 according to the present invention includes the semiconductor light emitting device 13 emitting ultraviolet light.
2 and a display panel 460. On the back surface of the display panel 460, predetermined characters, pictures, and the like are drawn by a plurality of phosphors having different emission colors. Semiconductor light emitting device 132
Emitted from the display panel 460 is subjected to wavelength conversion by the phosphor on the back surface of the display panel 460 to display a pattern such as a predetermined character or picture.

Further, the semiconductor light emitting device 1 emitting ultraviolet light
A semiconductor light emitting device 130 may be arranged in place of 32. In this case, predetermined characters or pictures on the display panel can be displayed using visible light such as white light emitted from the semiconductor light emitting device 130 as a backlight.

The display device 450 according to the present invention includes, for example,
It can be applied to a very wide range of applications such as in-vehicle indicator lamps, display lamps for various toys, various warning lights, and emergency lights.

According to the present invention, display luminance is higher than that of a conventional display device using a fluorescent lamp or a light bulb, and
The advantage is that the power consumption is small, the life is extremely long, and the mechanical strength against vibration, impact and the like is remarkably improved.

Next, a ninth embodiment of the present invention will be described. FIG. 10 is a schematic diagram illustrating a semiconductor light emitting device according to a ninth embodiment of the present invention. That is, the semiconductor light emitting device 500 according to the present invention includes the semiconductor light emitting element 132 that emits ultraviolet light, the first light reflection unit 510, the wavelength conversion unit 520, the second light reflection unit 530, and the light absorption unit 540.
Are provided in this order.

The first light reflecting section 510 in the present embodiment
Has wavelength selectivity such that ultraviolet light emitted from the semiconductor light emitting element 132 is transmitted, and secondary light such as visible light, which is wavelength-converted and emitted by the wavelength converter 520, is reflected. That is, the configuration is such that the reflectance for ultraviolet light from the semiconductor light emitting element 132 is low and the reflectance for light of the secondary light wavelength from the wavelength conversion unit 520 is high.

Such wavelength selectivity can be realized, for example, by using a Bragg reflector.
That is, by alternately laminating two types of thin films having different refractive indexes, it is possible to form a reflecting mirror having a high reflectance for light in a specific wavelength region. For example, assuming that the wavelength of the primary light is λ and the light refractive index of the thin film layer is n, two types of thin films each having a film thickness of λ / (4n) are alternately laminated, whereby the primary light It is possible to form a reflector having a very high reflectance. It is desirable that the two types of thin films have a large difference in optical refractive index. As a combination thereof, for example, silicon oxide (SiO ₂ ) and titanium oxide (TiO ₂ ), aluminum nitride (AlN) and indium nitride (InN), or a thin film made of any of these materials, aluminum gallium A thin film of any material such as arsenic, aluminum / gallium phosphide, tantalum pentoxide, polycrystalline silicon, and amorphous silicon may be appropriately combined.

The wavelength converter 520 is provided for the semiconductor light emitting device 13.
2 has a role of absorbing the ultraviolet light emitted from 2 and emitting secondary light of a longer wavelength. The structure can be, for example, a layer in which a predetermined medium contains a phosphor. The phosphor absorbs ultraviolet light emitted from the semiconductor light emitting element 132 and is excited to emit light having a predetermined wavelength.
The next light is emitted. For example, the ultraviolet light emitted from the semiconductor light emitting element 132 is light having a wavelength of about 330 nm, and the secondary light wavelength-converted by the phosphor can have a predetermined wavelength in the visible light or infrared region. .
The wavelength of the secondary light can be adjusted by appropriately selecting the material of the phosphor. As a phosphor that efficiently absorbs primary light in the ultraviolet region and emits secondary light efficiently, for example, as a phosphor that emits red light, Y ₂ O ₂ S: E
u, which emit blue light include (Sr, Ca,
Ba (Eu) ₁₀ (PO ₄ ) ₆ .Cl ₂ , which emits green light, includes 3 (Ba, Mg, Eu, Mn) O · 8
Al ₂ O _{3 and the} like can be mentioned. By mixing these fluorescent substances in an appropriate ratio, almost all colors in the visible light region can be expressed.

These fluorescent materials often have an absorption peak in a wavelength band around 330 nm. Therefore, in order to perform wavelength conversion efficiently with these fluorescent substances, it is desirable that the semiconductor light emitting element 132 emits ultraviolet rays in a wavelength band around 330 nm.

Next, the second light reflecting section 530 will be described. The light reflecting unit 530 is a reflecting mirror having wavelength selectivity, and has a role of reflecting ultraviolet light and transmitting secondary light in light incident from the wavelength converting unit 520. That is, the light reflecting portion 530 reflects the light of the ultraviolet wavelength,
It functions as a cut-off filter or a band-pass filter that transmits light of the wavelength of the next light. As a specific configuration, for example, a Bragg reflector as described above can be used.

By arranging such a light reflecting section 530, the ultraviolet rays that have passed through the wavelength converting section 520 and leaked can be reflected with high efficiency and returned to the wavelength converting section 520 again. The ultraviolet light returned in this manner is wavelength-converted in the wavelength conversion unit 520 and passes through the light reflection unit 530 as secondary light. That is, by arranging the light reflecting portion 530 on the light emission side of the wavelength converting portion 520, it is possible to prevent the ultraviolet rays from leaking to the outside, and to return the ultraviolet light transmitted through the wavelength converting portion 520 to perform wavelength conversion with high efficiency. Will be able to Further, since ultraviolet light from the outside can be reflected by the light reflecting section 530, the problem that the wavelength converting section 520 is excited by disturbance light to generate unnecessary light can also be solved.

Next, the light absorbing section 540 will be described.
The light absorbing portion is an absorber having wavelength selectivity, and has a role of absorbing ultraviolet light with high efficiency and transmitting secondary light. That is, it has absorption characteristics such that the absorptance for light of the wavelength of ultraviolet light is high and the absorptivity for light of the wavelength of secondary light is low. As a specific configuration, for example, a configuration in which a predetermined absorber is dispersed in a translucent medium can be given. Examples of such an absorber include cadmium red and red iron oxide when the secondary light is red light, and cobalt blue and red light when the secondary light is blue light. Ultramarine and the like.

By providing such a light absorbing portion 540, it is possible to absorb ultraviolet rays transmitted through the light reflecting portion 530 to prevent leakage to the outside, and to adjust the spectrum of light to be taken out to the outside. It is also possible to improve the color purity. Also, external ultraviolet light is absorbed by the light absorbing portion 54.
0, the wavelength conversion unit 52
It is also possible to solve the problem that unnecessary light emission is caused by excitation of 0.

According to the present embodiment, the semiconductor light emitting device 13
The ultraviolet light emitted from 2 passes through the first light reflection unit 510 and enters the wavelength conversion unit 520, where the wavelength is converted into secondary light. The ultraviolet light transmitted without wavelength conversion in the wavelength conversion unit 520 is reflected by the second light reflection unit 530 and returned to the wavelength conversion unit 520 again. Further, the ultraviolet light transmitted through the second light reflection portion 530 is absorbed by the light absorption portion 540, and leakage to the outside is prevented.

On the other hand, the 2
Of the next light, the light component emitted in the direction of the second light reflecting portion 510 can be extracted through the light reflecting portion 530 and the light absorbing portion 540 to the outside. Further, the wavelength converter 52
Semiconductor light emitting element 132 of the secondary light emitted from
The light component emitted in the direction of is reflected by the first light reflection unit 510, and can be extracted to the outside through the wavelength conversion unit 520, the light reflection unit 530, and the light absorption unit 540.

Here, when the first light reflecting section 510 is not provided, the semiconductor light emitting element 132
The secondary light emitted in the direction is absorbed or irregularly reflected by the semiconductor light emitting element 132 and cannot be effectively extracted to the outside. On the other hand, according to the present embodiment, by providing the first light reflecting section 510, the secondary light emitted from the wavelength converting section 520 in the direction of the semiconductor light emitting element 132 is reflected by the light reflecting section 510. As a result, it can be efficiently taken out to the outside. That is, the light is subjected to multiple reflection between the two light reflecting portions, and finally most of the light is wavelength-converted and extracted to the outside. Therefore, a highly efficient light emitting device with extremely high extraction efficiency can be realized.

Next, the details of the semiconductor light emitting element 132 that emits ultraviolet light suitable for use in the present invention will be described.

FIG. 11 is a schematic diagram showing a sectional structure of a semiconductor light emitting device 132 suitable for use in the present invention. That is, the semiconductor light emitting device 132 is a light emitting diode (LED) that emits light in the ultraviolet wavelength region. As shown in FIG. 11, the semiconductor light emitting device 132 includes a sapphire substrate 1001
It has a configuration in which semiconductor layers 1002 to 1008 are stacked thereon. The crystal growth of each semiconductor layer can be performed by, for example, a charged metal chemical vapor deposition (MOCVD) method. The thickness and growth temperature of each semiconductor layer will be exemplified below.

GaN buffer layer 1002... 0.05 μm, 550 ° C. n-GaN contact layer 1003... 4.0 μm, 1100 ° C. n-AlGaN cladding layer 1004... 0.2 μm, 110 ° C. n-BGaN active layer 1005. 0.5 μm, 1200 ° C. p-AlGaN first cladding layer 1006... 0.05 μm, 1100 ° C. p-AlGaN second cladding layer 1007... 0.2 μm, 1100 ° C. p-GaN contact layer 1008. The electrodes 1009 and 1010 for current injection are respectively composed of an n-GaN contact layer 1003 and a p-G
It is formed on the aN contact layer 1008. The difference between the semiconductor light emitting device 132 and the conventional device is that the active layer 10
A point is that a gallium nitride based semiconductor containing boron (B) is used in 05 and AlGaN is used in an adjacent layer. Conventionally, the development of a crystal containing B has been focused on BN, and SiC is used as the substrate crystal, and a high growth temperature of about 1300 ° C. is required as a crystal growth temperature. However, when trying to mix B into GaN, there is a problem that B has low solubility in the GaN crystal and has a large lattice mismatch with SiC used for the substrate. For this reason, for example, a ternary mixed crystal of BGaN having high quality in terms of the flatness of the surface morphology of the crystal has not been obtained.

The advantage of the present semiconductor light emitting device 132 is that B
By using AlGaN containing Al with high heat resistance for the GaN underlayer, a high-quality BGaN crystal can be grown. That is, AlGaN is heated to 1100 ° C.
Even if the growth temperature is raised to 1200 ° C., which is relatively high for gallium nitride-based growth, the flatness of the crystal surface is maintained, so that a good-quality BGaN crystal can be grown with good flatness. .

According to the experiment of the present inventor, when the growth temperature was further increased, the surface roughness considered to be due to the escape of N from the AlGaN surface became remarkable.
Since the lattice mismatch with GaN increases, the grown B
The surface flatness of the GaN layer deteriorated. Here, as the concentration of B increases, the flatness of the crystal surface tends to deteriorate, and B _x Ga ₁ -xN in which a crystal having a flat surface is obtained.
The B mixed crystal ratio (X) was 0.1 or less. It is still difficult to mix B at a higher concentration.

However, it has been found that the mixed crystal composition obtained by the present inventors has a sufficient mixed crystal ratio for a light emitting device in the ultraviolet wavelength region, and that the wavelength corresponds to 365 to 300 nm.

Another advantage of this structure is that a light emitting portion containing BGaN can be grown on the n-GaN contact layer 1003 which has been grown relatively thick. In forming the element structure as shown in FIG. 11, it is necessary to expose the n-type contact layer 1003 by etching the semiconductor layer when forming the n-side electrode 1009. In order to increase the tolerance of the processing accuracy in this etching step, it is desirable to grow the n-type contact layer 1003 to a certain thickness. However, BGaN mixed crystals make it difficult to grow a thick film and lower the yield of the etching process, so that it is not suitable for use as an n-type contact layer.

The BGaN mixed crystal has a B mixed crystal ratio lattice-matched to a 6H SiC substrate, and has a conductive Si
When growing on a C substrate, an etching process for forming an electrode is not required, and a thick crystal is not necessarily required. However, the B mixed crystal ratio at that time is as high as 0.2, and crystal growth itself is difficult, and the SiC substrate becomes opaque to the wavelength of ultraviolet light, which does not simply lead to improvement in device characteristics.

Under the circumstances described above, the GaN layer / AlG in the semiconductor light emitting device 132 according to the present invention.
The structure in which the BGaN light emitting layer is laminated on the aN layer has a thick and flat GaN layer / AlGa layer without requiring lattice matching conditions.
N layer can be grown, and L
It is very effective in realizing ED.

In the configuration shown in FIG. 11, B _x Ga _{1 -x}
When the B mixed crystal ratio (X) of the N active layer 1005 is set to 0.05, p
-Al _y Ga ₁ -yN first cladding layer 1006 has an Al mixed crystal ratio (Y) of 0.3 and n-Al _z Ga _{1 -z} N cladding layer 100
4 and Al of _{p-Al z Ga 1-z} N cladding layer 1007
A semiconductor multilayer structure with a mixed crystal ratio (Z) of 0.2 is created,
As a result of processing the chip into a 350 μm square chip to produce an LED, it was possible to obtain ultraviolet light having an emission spectrum peak of about 330 nm. The emission intensity when the operating current was 20 mA was about 10 μW.

FIG. 12 shows that silicon (S
It is a graph which shows the relationship between the silicon concentration and photoluminescence (PL) luminescence intensity at the time of doping i). That is, the horizontal axis in the figure represents the silicon concentration in BGaN, and the vertical axis represents the PL emission intensity in arbitrary units. As can be seen from the figure, the light emission intensity of the LED changes depending on the silicon concentration. That is, with the increase of silicon concentration, rapidly emission intensity increases from around 1E16 cm ^-3, the emission intensity at around 1E20 cm ^-3 to about 1E18 is maximized, the more high silicon concentration, the emission intensity sharply decreased I do. According to experiments performed by the present inventors, such a tendency does not change even when the B mixed crystal ratio is changed, and similar results were obtained. In the layer structure shown in FIG. 11, when the BGaN active layer 1005 was doped with 1E19 cm ^{−3 of} silicon, the emission wavelength remained unchanged at 330 nm and was 2 nm.
The emission intensity at 0 mA improved to about 2 mW. Further, as a result of an experiment in which the silicon concentration of the active layer 1005 was changed,
The silicon concentration is from 1E17 cm ^-3 to 1E21c
In the range of m ^-3 , it was found to be practically suitable for improving characteristics and forming a laminated structure.

FIG. 13 is a diagram showing a schematic sectional structure of an ultraviolet light emitting semiconductor light emitting device according to another embodiment of the present invention. That is, the semiconductor light emitting element 132B has
It has a laminated structure grown on an H-type SiC substrate 1101. The film thickness and growth temperature of each layer are almost the same as those described above with reference to FIG. 11, except that the GaN buffer layer 1102 is doped n-type and the n-side electrode 1109 is formed on the back side of the SiC substrate 1101. Is a point. Crystal growth is performed, for example, by metal organic chemical vapor deposition (MO).
CVD method). As previously mentioned,
When the 6H SiC substrate 1101 is adopted,
Since it becomes opaque in the ultraviolet wavelength region, there is a disadvantage that light emitted to the substrate side cannot be taken out of the light emitting element. However, the effective lattice mismatch ratio with GaN is 3.4% compared to 13.8% of the sapphire substrate, which is smaller in the 6H-SiC substrate, and the density of dislocations and various crystal defects caused by the lattice mismatch. Can be reduced. Since the quality of the underlying crystal layer of the BGaN active layer 1105 is improved in this manner, the BGaN crystal 11
In addition, the crystal quality of the light-emitting element 05 can be improved and the light-emitting characteristics of the light-emitting element can be improved. That is, the 6H SiC substrate 1101
The advantage of employing is that the light emission characteristics are improved due to the improvement in crystallinity.

In the structure shown in FIG. 13, B _x Ga _{1 -x}
When the B mixed crystal ratio (X) of the N active layer 1105 is 0.05, p
-Al _y Ga ₁ -yN first cladding layer 1106 has an Al composition ratio (Y) of 0.3 and n-Al _z Ga _{1 -zN} cladding layer 110
4 and p-Al _z Al of Ga _1-z N cladding layer 1107
A layer structure with a mixed crystal ratio (Z) of 0.2 was created,
When an LED was fabricated by processing the chip into an m-square chip, light emission having a light emission spectrum peak of 330 nm could be obtained.

The B _x Ga ¹ -xN active layer 1105 is doped with silicon to reduce the silicon concentration in the crystal to 1E19.
In the device prepared as cm ⁻³ , the operating current was 20
The emission intensity at the time of mA was about 1.3 mW.

FIG. 14 is a schematic sectional view showing a modified example of the semiconductor light emitting device 132B shown in FIG. That is,
The semiconductor light emitting device 132C is obtained by etching the semiconductor laminated structure of the semiconductor light emitting device 32B shown in FIG. 13 from the front side to expose the n-GaN contact layer 1103 and form the n-side electrode 1109. In this structure, the effect on the BGaN active layer which is important for the device characteristics is the same, and its usefulness is great.

The embodiments of the present invention described above are not limited to the illustrated structure or the above-described manufacturing method. That is, although a BGaN mixed crystal is described as the light emitting layer, a BnAlGaN-based material may be used to form a metal junction capable of confining injected carriers, and is not limited to a BGaN ternary system. .

The contact layer forming the p-side electrode is not limited to the GaN layer. Any material selected from InAlGaN-based materials can satisfy the characteristics, and can absorb light from the active layer. In the case of a system, the characteristics can be sufficiently satisfied by reducing the film thickness. Further, in the above-described specific example, an LED has been described, but application to a gallium nitride based semiconductor laser (LD) is also possible. In addition, various modifications can be made without departing from the spirit of the present invention.

[0091]

The present invention is embodied in the form described above, and has the following effects.

First, according to the present invention, it is possible to provide various kinds of applied devices such as a lighting device having higher efficiency, lower power consumption, and an extremely longer life than conventional fluorescent lamps and electric bulbs.

Further, according to the present invention, it is possible to provide a lighting device or the like which has high mechanical strength against shocks and vibrations and has excellent reliability.

Further, according to the present invention, the size and weight can be easily reduced, and the manufacturing cost and the transportation cost can be reduced.

Further, according to the present invention, the light emission from the light emitting layer of the semiconductor light emitting element is not directly extracted, but the wavelength is converted by the fluorescent substance. The problem that the emission wavelength varies depending on the temperature or the like can be solved. That is, according to the present invention, the emission wavelength is extremely stable, and the emission luminance and the emission wavelength can be controlled independently.

According to the present invention, a plurality of emission wavelengths can be easily obtained by appropriately combining the fluorescent substances used. For example, by appropriately mixing red (R), green (G), and blue (B) fluorescent substances and incorporating them into a light-emitting element, white light can be easily emitted.

Further, according to the present invention, by using GaN containing boron for the light emitting layer, it is possible to obtain ultraviolet rays having a wavelength of about 330 nm with extremely high intensity, which can excite the phosphor extremely efficiently.

Further, according to the present invention, the wavelength conversion is extremely efficiently performed by reflecting and confining the ultraviolet light emitted by the semiconductor light emitting element and by guiding the secondary light emitted by the phosphor to the outside. As a result, secondary light can be extracted to the outside.

Further, according to the present invention, it is not necessary to appropriately select and change the material and structure of the built-in semiconductor light emitting element according to the emission wavelength. For example, conventionally, an AlGaAs-based material is used to emit light in red, and a GaAsP-based or InGaAlP-based material is used for yellow.
Material, InGaAlP or Ga
There is a problem that an optimum material such as a P-based material and a blue-colored InGaN-based material must be selected according to the wavelength. In contrast, according to the present invention, the type of the fluorescent substance may be appropriately selected according to the emission wavelength,
There is no need to change the semiconductor light emitting element.

Further, according to the present invention, even when it is necessary to arrange semiconductor light-emitting elements having different light-emitting colors, it is sufficient to change the light-emitting color only by changing the kind of the phosphor to be used. And the structure can be the same. Therefore, the configuration of the light emitting device can be extremely simplified, the manufacturing cost can be significantly reduced, the reliability is high, and the driving current, the supply voltage, the element size, and the like are commonly used. This also has the advantage that the range of application can be significantly expanded.

As described above, according to the present invention, with a relatively simple configuration, an illuminating device that can emit light with extremely stable emission wavelengths and with high luminance at various wavelengths from the visible light to the infrared region. , And various other applied devices can be provided, and the industrial merits are great.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a lighting device according to a first embodiment of the present invention. That is, FIG. 2A is an overall perspective view, FIG. 2B is a cross-sectional view thereof, and FIG.
FIG. 3 is a schematic plan view of the wiring board.

FIG. 2 is a schematic sectional view illustrating a configuration of a semiconductor light emitting device suitable for use in the present invention.

FIG. 3 is a schematic view illustrating a flash device for a camera according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a lamp according to a third embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating a reading device according to a fourth embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a projection device according to a fifth embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a purification device according to a sixth embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating an ultraviolet irradiation device according to a seventh embodiment of the present invention.

FIG. 9 is a schematic view illustrating a display device according to an eighth embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating a light emitting device according to a ninth embodiment of the present invention.

FIG. 11 shows a semiconductor light emitting device 132 suitable for use in the present invention.
It is a schematic diagram showing the cross-sectional configuration of FIG.

FIG. 12 is a graph showing the relationship between silicon concentration and photoluminescence (PL) emission intensity when silicon (Si) is doped to BGaN.

FIG. 13 is a diagram illustrating a schematic cross-sectional structure of an ultraviolet light emitting semiconductor light emitting device according to another embodiment of the present invention.

FIG. 14 is a schematic cross-sectional view showing a modification of the semiconductor light emitting device 132B shown in FIG.

FIG. 15 is a schematic diagram illustrating a schematic configuration of a conventional fluorescent lamp system.

[Explanation of symbols]

 Reference Signs List 100 lighting device 110 wiring board 120A, 120B envelope 130 semiconductor light emitting device 132 semiconductor light emitting element 134 lead frame 136 phosphor 138 resin 150 camera 152 lens 154 finder 158 pulse generator 200 lamp unit 210 concave mirror 250 reading device 260A , B, C light receiving unit 300 projection device 310 concave mirror 320 projection lens 340 document 342 screen 350 purification device 355A water 355B purified water 360 purification circuit 370 ozone generator 400 ultraviolet irradiation device 410 concave mirror 440 target 450 display device 460 display panel 500 semiconductor light emission Apparatus 510 First light reflecting section 520 Wavelength converting section 530 Second light reflecting section 540 Light absorbing section 1001 Substrate 1002 Buffer layer 1003 n Layers 1004,1006,1007 cladding layer 1005 emitting layer 1008 contact layer 1009 and 1010 electrodes

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 1/78 C02F 1/78 F21M 1/00 F21M 1/00 A F21V 19/00 F21V 19/00 P // H01S 3/18 H01S 3/18 (72) Inventor Koichi Nitta 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Kawasaki Office (72) Inventor Chisato Furukawa 7-1 Nisshin-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa-ken Toshiba Electronics Engineering Corporation

Claims (40)

[Claims] A semiconductor light emitting device that emits ultraviolet light; and a semiconductor light emitting device that absorbs the ultraviolet light emitted by the semiconductor light emitting device.
A phosphor that emits secondary light having a longer wavelength than the ultraviolet light. 2. A circuit board comprising: a wiring board; a plurality of semiconductor light emitting devices provided on the wiring board; and a light-transmitting envelope provided to cover a periphery of the wiring board. The semiconductor light emitting device includes: a semiconductor light emitting element that emits ultraviolet light; and a semiconductor light emitting element that absorbs the ultraviolet light emitted by the semiconductor light emitting element.
A phosphor that emits secondary light having a wavelength longer than the ultraviolet light. 3. The lighting device according to claim 2, wherein said semiconductor light emitting device is a surface mount type. 4. A plurality of units formed by connecting a predetermined number of said semiconductor light emitting devices out of said plurality of semiconductor light emitting devices in series, and said plurality of units are connected in parallel with each other. The lighting device according to claim 2 or 3, wherein: 5. A wiring board, a plurality of semiconductor light emitting elements emitting ultraviolet light provided on the wiring board, and a light-transmitting envelope provided so as to cover the periphery of the wiring board. A phosphor is provided on an inner wall surface of the envelope, and absorbs the ultraviolet light emitted by the semiconductor light emitting element, and emits secondary light having a longer wavelength than the ultraviolet light. A lighting device, comprising: 6. A plurality of units formed by connecting a predetermined number of the semiconductor light emitting devices among the plurality of semiconductor light emitting devices in series are formed, and the plurality of units are connected in parallel with each other. The lighting device according to claim 5, wherein 7. The lighting device according to claim 1, wherein the secondary light is visible light. 8. The illumination device according to claim 7, wherein said visible light has intensity peaks in red, green, and blue wavelength regions, respectively. 9. The semiconductor light-emitting device according to claim 1, further comprising a conversion circuit for converting a high-frequency voltage to a DC voltage, wherein said conversion circuit is connected to a power supply of a fluorescent lamp so as to drive said semiconductor light-emitting device.
The lighting device according to any one of Items 1 to 8, 10. A semiconductor light emitting device that emits ultraviolet light, and the semiconductor light emitting device absorbs the ultraviolet light emitted by the semiconductor light emitting device,
A lighting device, comprising: a phosphor that emits secondary light having a wavelength in a visible light region; and a pulse generator that supplies a pulsed drive current to the semiconductor light emitting element. 11. A semiconductor light emitting device that emits ultraviolet light, and wherein the semiconductor light emitting device absorbs the ultraviolet light emitted by the semiconductor light emitting device.
A lighting device, comprising: a phosphor that emits secondary light having a wavelength in the visible light region; and a concave mirror that reflects the visible light and irradiates the phosphor in a predetermined direction. 12. A first light having a wavelength selectivity between the semiconductor light emitting element and the phosphor, which transmits the ultraviolet light and reflects the secondary light emitted from the phosphor. The reflective film is further provided with a reflective film.
2. The lighting device according to claim 1. 13. A second light having a wavelength selectivity such that the ultraviolet light is reflected and the secondary light emitted from the phosphor is transmitted to a side opposite to the semiconductor light emitting element as viewed from the phosphor. The lighting device according to claim 1, further comprising a reflective film. 14. A light-absorbing material having a wavelength selectivity that absorbs the ultraviolet light and transmits the secondary light emitted from the fluorescent material is provided on a side opposite to the semiconductor light-emitting element when viewed from the fluorescent material. 2. The method according to claim 1, further comprising:
3. The lighting device according to any one of 3. 15. The semiconductor light emitting device according to claim 1, wherein the light emitting layer contains a gallium nitride based semiconductor.
The lighting device according to any one of the above. 16. The semiconductor light emitting device according to claim 1, wherein the light emitting layer contains boron, gallium, and nitrogen.
15. The lighting device according to any one of 14. 17. A semiconductor light emitting device comprising: a substrate; a first conductivity type GaN layer deposited on the substrate; a first conductivity type cladding layer made of GaN containing aluminum; and a GaN containing boron. 17. The lighting device according to claim 16, further comprising: a light emitting layer made of GaN, and a cladding layer of a second conductivity type made of GaN containing aluminum. 18. The light emitting wavelength of the semiconductor light emitting device is about 3
The lighting device according to claim 1, wherein the thickness is 30 nm. 19. A semiconductor light emitting device that emits ultraviolet light, and the semiconductor light emitting device absorbs the ultraviolet light emitted by the semiconductor light emitting device,
A phosphor that emits light having a wavelength longer than the ultraviolet light; and a light receiving unit that detects light having the longer wavelength reflected externally, and irradiates the document with light emitted by the phosphor to read the document. A reading device characterized by being improved. 20. The reading device according to claim 19, wherein the semiconductor light emitting element includes a gallium nitride based semiconductor in a light emitting layer. 21. The semiconductor light emitting device according to claim 19, wherein the light emitting layer contains boron, gallium, and nitrogen.
Or the reading device according to 20. 22. A semiconductor light emitting device comprising: a substrate; a first conductivity type GaN layer deposited on the substrate; a first conductivity type clad layer made of GaN containing aluminum; and GaN containing boron. 22. The reader according to claim 21, further comprising: a light-emitting layer formed of a second conductive type made of GaN containing aluminum. 23. An emission wavelength of the semiconductor light emitting device is about 3
23. The reading device according to claim 19, wherein the reading device has a thickness of 30 nm. 24. A semiconductor light emitting device that emits ultraviolet light, and the semiconductor light emitting device absorbs the ultraviolet light emitted by the semiconductor light emitting device,
A projection device, comprising: a phosphor that emits visible light; and an optical system that collects the visible light and projects the same on a screen, wherein the pattern on the translucent medium is enlarged and projected. . 25. The projection apparatus according to claim 24, wherein said semiconductor light emitting element includes a gallium nitride based semiconductor in a light emitting layer. 26. The semiconductor light emitting device according to claim 24, wherein the light emitting layer contains boron, gallium, and nitrogen.
Or the projection device according to 25. 27. A semiconductor light emitting device comprising: a substrate; a first conductivity type GaN layer deposited on the substrate; a first conductivity type clad layer made of GaN containing aluminum; and GaN containing boron. 27. The projection apparatus according to claim 26, further comprising: a light emitting layer made of GaN, and a second conductivity type clad layer made of GaN containing aluminum. 28. An emission wavelength of the semiconductor light emitting device is about 3
The projection device according to any one of claims 24 to 27, wherein the projection device has a thickness of 30 nm. 29. A purifying apparatus comprising: a purifying circuit through which a liquid or a gas passes; and a semiconductor light emitting element which emits ultraviolet light provided on the purifying circuit. 30. An ozone generator is further provided on the purification circuit, and the ultraviolet light is applied to a liquid containing ozone generated by the ozone generator.
Purification device according to the above. 31. The purifying apparatus according to claim 29, further comprising a heating device on the purifying circuit, wherein the gas purified in the purifying circuit is heated and exhausted. 32. The semiconductor light emitting device according to claim 29, wherein the light emitting layer contains a gallium nitride based semiconductor.
Purification device according to any one of the preceding claims. 33. The semiconductor light emitting device according to claim 29, wherein the light emitting layer contains boron, gallium, and nitrogen.
33. The purifying device according to any one of -32. 34. A semiconductor light emitting device comprising: a substrate; a first conductivity type GaN layer deposited on the substrate; a first conductivity type cladding layer made of GaN containing aluminum; and a GaN containing boron. 34. The purification device according to claim 33, further comprising at least: a light emitting layer made of a GaN containing aluminum and a second conductivity type clad layer made of GaN containing aluminum. 35. An emission wavelength of the semiconductor light emitting device is about 3
The purification device according to any one of claims 29 to 34, wherein the thickness is 30 nm. 36. A semiconductor light emitting device that emits ultraviolet light, and the semiconductor light emitting device absorbs the ultraviolet light emitted by the semiconductor light emitting device,
A display device, comprising: a display panel on which a phosphor that emits visible light is deposited. 37. The display device according to claim 36, wherein the semiconductor light emitting element includes a gallium nitride based semiconductor in a light emitting layer. 38. The semiconductor light emitting device according to claim 36, wherein the light emitting layer contains boron, gallium, and nitrogen.
Or the display device according to 37. 39. A semiconductor light emitting device comprising: a substrate; a first conductivity type GaN layer deposited on the substrate; a first conductivity type cladding layer made of GaN containing aluminum; and GaN containing boron. 39. The display device according to claim 38, further comprising at least: a light-emitting layer formed of a second conductive type made of GaN including aluminum. 40. An emission wavelength of the semiconductor light emitting device is about 3
The display device according to any one of claims 36 to 39, wherein the thickness is 30 nm.