JP2011065946A - Led illumination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED illumination device capable of securing superior light distribution characteristics while achieving thin shape constitution by using a thin LED compared with an incandescent lamp. <P>SOLUTION: Since a first reflector RL1 is installed, a portion of light emitted from the center light-emitting diode LED is reflected by the first reflector RL1 and emitted so as to approach an optical axis, and the light distribution characteristics become superior. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an LED (light emitting diode) illumination device.

  In recent years, high-intensity white LEDs have been developed, and are expected to replace incandescent lamps in the lighting field and the like due to their thinness, long life, and power saving effect. However, the problem of using white LEDs as a lighting device is that the individual illuminance is smaller than incandescent lamps. About this problem, required illuminance can be secured by using a plurality of white LEDs. Patent Document 1 discloses an illumination device having a plurality of LED light emitting diodes and a reflector that reflects light emitted from the LED light emitting diodes in a predetermined direction.

JP 2008-16412 A

  However, according to the examination results of the present inventors, for example, when a plurality of light emitting diodes are provided as in the illumination device disclosed in Patent Document 1, light emitted from the central light emitting diode is reflected on the reflector. It has been found that the amount of light directly emitted from the lighting device increases without causing deterioration in light distribution characteristics. In contrast, if the length of the reflector in the optical axis direction is increased, the light emitted from the central light emitting diode and directly emitted from the lighting device can be reduced, but the length of the lighting device in the optical axis direction is increased. There is a problem that the merit of using a thin LED light source is reduced.

  The present invention has been made in view of the problems of the prior art, and an LED illumination device that can ensure a good light distribution characteristic while realizing a thin configuration by using a thin LED compared to an incandescent lamp. The purpose is to provide.

The LED lighting device according to claim 1,
An LED light source;
A first reflector arranged to surround a portion of the LED light source;
And a second reflector disposed so as to surround all of the LED light sources so as to surround the first reflector.

  According to the present invention, the second reflector is disposed so as to surround the first reflector, that is, is a double reflector, so that the outer reflector is used to reflect the light emitted near the center. Therefore, it is not necessary to increase the height of the reflector, the height of the reflector can be reduced, and a thin lighting device that takes advantage of the thinness of the LED can be obtained. In addition, when the reflecting surface of the reflector is formed by vapor deposition of aluminum, silver, or the like, there is an advantage that vapor deposition is easy because the height of the reflector can be reduced. Furthermore, the light emitted from a part of the LED light source is reflected by the first reflector, and the light emitted directly from the LED lighting device is reduced, thereby ensuring good light distribution characteristics. Moreover, since the light distribution of each of the first reflector and the second reflector can be controlled, the degree of freedom of light distribution control is increased. This is particularly advantageous when the light distribution angle is narrow. As the degree of freedom of light distribution control increases, the degree of freedom of arrangement of the LED light source also improves.

  According to a second aspect of the present invention, in the LED lighting device according to the first aspect, the LED light source has a plurality of light emitting units, and the first reflector is a part of the plurality of light emitting units. It arrange | positions so that a light emission part may be enclosed, and a said 2nd reflector is arrange | positioned so that all of these light emission parts may be enclosed. As a result, the ratio of the light emitted from the part of the light emitting units being reflected by the first reflector is increased, and the light emitted directly from the LED lighting device is reduced, thereby ensuring good light distribution characteristics. can do.

  According to a third aspect of the present invention, in the LED lighting device according to the first aspect, the LED light source has a single light emitting unit, and the first reflector has a part of the single light emitting unit. It arrange | positions so that it may surround, and the said 2nd reflector is arrange | positioned so that all the said single light emission parts may be enclosed. As a result, the ratio of the light emitted from a part of the single light emitting unit being reflected by the first reflector is increased, and the light emitted directly from the LED lighting device is reduced, thereby providing a good light distribution. Characteristics can be secured.

  The LED lighting device according to claim 4 is the lens according to any one of claims 1 to 3, wherein the light beam reflected by the first reflector and the light beam reflected by the second reflector are incident. It is characterized by having. By allowing the light emitted from the LED light source to be emitted from the LED illumination device via the lens, it is possible to obtain even better light distribution characteristics.

  The LED illumination device according to claim 5 is the lens according to any one of claims 1 to 3, in which the light beam reflected by the first reflector and the light beam reflected by the second reflector are incident. It is characterized by not having. The light utilization efficiency can be improved by emitting the light emitted from the LED light source from the LED illumination device without passing through the lens.

  The LED lighting device according to claim 6 is the invention according to any one of claims 1 to 5, wherein the first reflector and the second reflector have a circular cross-sectional shape in the direction perpendicular to the optical axis. Features. Thereby, a circular light distribution characteristic can be obtained.

  The LED lighting device according to claim 7 is the invention according to any one of claims 1 to 5, wherein the first reflector and the second reflector have an elliptical cross-sectional shape in the direction perpendicular to the optical axis. It is characterized by. Thereby, an elliptical light distribution characteristic can be obtained.

  The LED (Light Emitting Diode) illumination device according to the present invention includes an LED light source, and a first reflector and a second reflector that reflect light emitted from the LED light source. Furthermore, both the aspect which has the lens which passes the light reflected by the 1st reflector and the 2nd reflector, and the aspect which does not have a lens can be considered.

  Various LED light sources can be used, but white LEDs are preferably used.

  As the white LED, a combination of a blue LED chip and a phosphor such as a YAG phosphor that emits yellow light by blue light emitted from the blue LED chip is preferably used, but a blue LED chip, a green LED chip, and a red LED are used. It may be a white LED that forms white light in combination with a chip. As white LED, what was described, for example in Unexamined-Japanese-Patent No. 2008-231218 can be used, However, It is not restricted to this.

  Specifically, the white LED light source in the present invention includes an LED chip and a phosphor layer formed on the LED chip so as to cover the LED chip. The LED chip emits light having a first predetermined wavelength. In the present embodiment, the LED chip emits blue light. However, the wavelength of the LED chip of the present invention and the wavelength of the emitted light from the phosphor are not limited, and the wavelength of the emitted light from the LED chip and the wavelength of the emitted light from the phosphor are in a complementary color relationship and the synthesized light is white. Any combination that provides light can be used.

  In addition, as such an LED chip, a well-known blue LED chip can be used. As the blue LED chip, any existing one including InxGa1-xN can be used. The emission peak wavelength of the blue LED chip is preferably 440 to 480 nm. In addition, as a form of the LED chip, the LED chip is mounted on the substrate and directly radiated upward or sideward, or the blue LED chip is mounted on a transparent substrate such as a sapphire substrate, and bumps are formed on the surface thereof. Any form of LED chip, such as a so-called flip chip connection type, in which it is formed and turned over and connected to an electrode on a substrate, can be applied.

  The phosphor layer has a phosphor that converts light having a first predetermined wavelength emitted from the LED chip into a second predetermined wavelength. In an embodiment described later, blue light emitted from the LED chip is converted into yellow light.

  The phosphor used for such a phosphor layer uses an oxide or a compound that easily becomes an oxide at a high temperature as a raw material of Y, Gd, Ce, Sm, Al, La and Ga, and converts them into a stoichiometric amount. The raw material is obtained by thoroughly mixing in a theoretical ratio. Alternatively, a coprecipitated oxide obtained by calcining a solution obtained by coprecipitation of oxalic acid with a solution obtained by dissolving a rare earth element of Y, Gd, Ce, and Sm in an acid at a stoichiometric ratio, and aluminum oxide and gallium oxide. Mix to obtain a mixed raw material. An appropriate amount of fluoride such as ammonium fluoride is mixed with this as a flux and pressed to obtain a molded body. The compact can be packed in a crucible and fired in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a sintered body having the phosphor emission characteristics.

  The first reflector and the second reflector surround the LED light source and reflect light emitted therefrom.

  As the material of the first reflector and the second reflector, a thin metal plate such as aluminum or steel may be used, glass, cyclic polyolefin, polycarbonate, or other thermoplastic resin, thermosetting resin, light You may make it form a reflective surface by vapor-depositing metals, such as aluminum and silver, on the surface of the base material which consists of curable resin, UV curable resin, a silicon | silicone, a ceramic. When a thermoplastic resin such as cyclic polyolefin or polycarbonate is used, it can be manufactured by injection molding, so that the manufacturing cost can be greatly reduced.

  The reflector has a reflecting surface that reflects light emitted from the LED light source. For the sake of convenience, the optical axis of the LED light source may be a line perpendicular to the plane of the LED chip at the center of the LED light source.

Examples of the reflecting surface of the reflector include the following two types.
1) The reflecting surface is a curved surface.
2) The reflecting surface is a combination of a plurality of planes.

  Since the light emitted from the LED light source has little directivity, there is also light emitted in a direction substantially perpendicular to the optical axis. Reflecting such light so as to approach the optical axis direction is preferable because the light use efficiency can be improved.

  The shape of the reflector viewed from the optical axis direction is preferably a circular or elliptical reflecting surface, but is not limited thereto, and may be a polygon. In this case, aluminum or silver may be vapor-deposited on the entire surface including the main body of the reflector, or aluminum or silver may be vapor-deposited only on a circular or elliptical reflecting surface portion.

  The cross-sectional shape of the first reflector and the second reflector in the direction orthogonal to the optical axis is preferably a circle or an ellipse, but is not limited to this, and may be a polygon. The first reflector has at least an inner side as a reflecting surface, but the outer side may be a reflecting surface or may not be a reflecting surface. The inside of the second reflector is a reflecting surface. Furthermore, you may have a 3rd reflector and a 4th reflector between the 1st reflector and the 2nd reflector. The first reflector and the second reflector are preferably arranged coaxially, but may be non-coaxial, and the heights in the optical axis direction are preferably equal to each other, but may be different.

  It is preferable that the reflector completely surrounds the light emitting part of the LED light source, but there may be a gap in part. In order to enclose the LED light source, it is sufficient that the proximity end of the reflecting surface of the reflector is located outside the LED light source in the direction orthogonal to the optical axis, and the distance between the light emission point and the proximity end is not limited. Moreover, the 1st reflector may be formed in the cylinder shape for every light emission part of the LED light source. The first reflector or the second reflector may be composed of a single member or a plurality of members. When the reflector is made of a single member, it is preferable to reduce the height of the reflector because it is difficult to perform vapor deposition if the reflector has a high height when the reflective surface is provided by vapor deposition or the like. However, the reflector may be formed in a divided state and may be formed by combining a plurality of members.

  Next, a case where a lens is provided will be described.

  Various lenses can be used. For example, a convex lens, a concave lens, a diffractive lens, a Fresnel lens, and the like are preferable examples.

  Examples of the lens material include glass, thermoplastic resins such as cyclic polyolefin and polycarbonate, thermosetting resins, photocurable resins, UV curable resins, and silicon. When a thermoplastic resin such as cyclic polyolefin or polycarbonate is used, it can be manufactured by injection molding, so that the manufacturing cost can be greatly reduced.

  The shape of the lens viewed from the optical axis direction is preferably matched to the shape of the reflector. For example, when the reflector is rectangular or square, the lens is preferably rectangular or square, and when the reflector is circular or elliptical, the lens is preferably circular or elliptical. However, even if the shape of the entire reflector is a rectangle or a square, the lens may be a circle or an ellipse according to the shape of the reflecting surface.

  The reflector and the lens are preferably overlapped in the optical axis direction. At this time, the reflector and the lens may be bonded with an adhesive or the like, or may have a fitting portion or the like to be fitted.

  According to the present invention, it is possible to provide an LED lighting device that can ensure a good light distribution characteristic while realizing a thin configuration by using a LED that is thinner than an incandescent lamp.

It is a perspective view of LED lighting apparatus EMT1 concerning 1st Embodiment, However, The light emitting diode is shown through. It is optical axis direction sectional drawing of LED lighting apparatus EMT1. It is an exploded view of LED lighting apparatus EMT1. Although it is a perspective view of LED lighting apparatus EMT2 concerning 2nd Embodiment, the light emitting diode is shown through. Although it is a perspective view of LED lighting apparatus EMT3 concerning 3rd Embodiment, the light emitting diode is shown through. Although it is a perspective view of LED lighting apparatus EMT4 concerning 4th Embodiment, the light emitting diode is seen through.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an LED illumination device EMT1 according to the first embodiment. FIG. 2 is a cross-sectional view of the LED illumination device EMT1 in the optical axis direction. FIG. 3 is an exploded view of the LED lighting device EMT2.

  Referring to FIG. 1, an LED illumination device EMT1 includes a circuit board CB, a plurality of light emitting diodes LED mounted on the circuit board CB, and a first reflector RL1 and a second reflector installed on the circuit board CB. RL2 is roughly configured.

  As shown in FIG. 2, the circuit board CB includes a substrate body BS made of aluminum, an insulating layer IL stacked on the substrate body BS, and a wiring pattern HP made of a conductor such as Cu formed on the insulating layer IL. It is roughly composed of A plurality of light emitting diodes (light emitting units) LEDs are respectively connected in parallel to the wiring pattern HP.

  Further, the light emitting diode LED is completely covered with a flat plate-molded phosphor-containing transparent resin body YEL (phosphor-containing transparent resin), and all the light emitted from the light-emitting diode LED is phosphor-containing transparent. It is configured to pass through the resin body YEL. With this configuration, for example, a blue light emitting diode is used as the light emitting diode LED, and a white phosphor can be emitted by using a yellow phosphor as the phosphor contained in the phosphor-containing transparent resin. The plurality of light emitting diodes LED are arranged in a matrix shape or a ring shape, and constitute an LED light source.

  Next, the first reflector RL1 is formed by, for example, rolling a thin plate material of aluminum or an aluminum alloy, has a tapered shape that increases in diameter as it goes upward, and has an inner reflection surface. In addition, the second reflector RL2 that coaxially surrounds the first reflector RL1 is also formed by, for example, rounding a thin plate of aluminum or an aluminum alloy, and has a tapered shape that increases in diameter toward the upper side. Is a reflective surface. The cross sections in the direction perpendicular to the optical axis of the first reflector RL1 and the second reflector RL2 are circular, but at least one of them may be elliptical.

  As shown in FIG. 3, the first reflector RL1 and the second reflector RL2 are manufactured separately, and the lower end of the first reflector RL1 includes a phosphor so as to surround the light emitting diode LED arranged in the center. The LED illumination device EMT1 can be formed by bonding and fixing to the transparent resin body YEL and bonding and fixing the lower end of the second reflector RL2 to the phosphor-containing transparent resin body YEL so as to surround all the light emitting diodes LED. .

  The operation of this embodiment will be described. When the light emitting diode LED emits blue divergent light by the electric power supplied from the outside via the wiring pattern HP, the divergent light is transmitted through the phosphor-containing transparent resin body YEL and converted into white light. Here, when the first reflector RL1 is not provided, as shown by a dotted line in FIG. 2, the light emitted from the central light emitting diode LED and not reflected by the second reflector RL2 is directly emitted from the LED illumination device EMT1. As a result, the amount of peripheral light increases and the light distribution characteristics deteriorate.

  On the other hand, according to the present embodiment, since the first reflector RL1 is provided, as shown by the solid line in FIG. 2, a part of the light emitted from the central light emitting diode LED is converted into the first reflector. Since the light is reflected by RL1 and emitted so as to approach the optical axis, the light distribution characteristic can be improved. In addition, since the height of the reflector can be reduced, it is advantageous for reducing the thickness of the lighting device. For example, in order to reduce the cost, it is advantageous when forming the reflector by evaporating aluminum or the like on a resin material. Furthermore, in this embodiment, since no lens is used, it is easier to control the light distribution characteristics than when the lens is transmitted, and the light emitted from the light emitting diode LED in the central portion and the light emitting diode LED in the outer portion is used. Each can be controlled, and at the same time, the light use efficiency can be increased. Further, according to the present embodiment, there is an advantage that there are few restrictions on the arrangement of the light emitting diodes LED.

  FIG. 4 is a perspective view of the LED illumination device EMT2 according to the second embodiment. The embodiment shown in FIG. 4 is different only in that the first reflector RL1 has a tapered shape whose diameter is increased downward. Since other configurations are the same as those of the above-described embodiment, the description thereof is omitted.

  FIG. 5 is a perspective view of the LED illumination device EMT3 according to the third embodiment. The embodiment shown in FIG. 5 is different in that a single light emitting diode LED is used as the LED light source. The lower end of the first reflector RL1 is adhered and fixed to the phosphor-containing transparent resin body YEL so as to surround the central portion of the light emitting diode LED, and the lower end of the second reflector RL2 is surrounded by the light emitting diode LED. The phosphor-containing transparent resin body YEL is adhesively fixed. Since other configurations are the same as those of the above-described embodiment, the description thereof is omitted.

  FIG. 6 is a cross-sectional view of an LED illumination device EMT4 according to the fourth embodiment. The embodiment shown in FIG. 5 is different in that a concave lens LS is bonded and fixed to the upper ends of the reflectors RL1 and RL2. By allowing the light reflected by the reflectors RL1 and RL2 to further pass through the concave lens LS, the degree of freedom for controlling the light distribution characteristics is increased. A convex lens may be bonded and fixed instead of the concave lens LS.

  The LED lighting device of the present invention can be used for various applications such as street lamps and room lights.

BS board body CB circuit board EMT1 illuminating device EMT2 illuminating device EMT3 illuminating device EMT4 illuminating device HP wiring pattern IL insulating layer LED light emitting diode LS concave lens RL1 first reflector RL2 second reflector YEL phosphor-containing transparent resin body

Claims (7)

An LED light source;
A first reflector arranged to surround a portion of the LED light source;
An LED lighting device comprising: a second reflector disposed so as to surround all of the LED light sources so as to surround the first reflector.   The LED light source includes a plurality of light emitting units, the first reflector is disposed so as to surround a part of the plurality of light emitting units, and the second reflector includes the plurality of light emitting units. The LED lighting device according to claim 1, wherein the LED lighting device is arranged so as to surround all of the portions.   The LED light source includes a single light emitting unit, the first reflector is disposed so as to surround a part of the single light emitting unit, and the second reflector is formed of the single light emitting unit. The LED illumination device according to claim 1, wherein the LED illumination device is disposed so as to surround all of the regions.   The LED illumination device according to claim 1, further comprising a lens on which the light beam reflected by the first reflector and the light beam reflected by the second reflector are incident.   The LED illumination device according to any one of claims 1 to 3, wherein the LED illumination device does not have a lens on which the light beam reflected by the first reflector and the light beam reflected by the second reflector are incident.   The LED lighting device according to any one of claims 1 to 5, wherein the first reflector and the second reflector have a circular cross-sectional shape in a direction orthogonal to the optical axis.   The LED lighting device according to any one of claims 1 to 5, wherein a cross-sectional shape of the first reflector and the second reflector in the direction perpendicular to the optical axis is an ellipse.

Images