JP2009170114A - Led bulb and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively radiate heat from a plurality of blue LED elements to increase the luminescent efficiency when obtaining white light through a yellow phosphor by using an LED module with the plurality of blue LED elements surface-mounted as a light source. <P>SOLUTION: The LED module 11A with the plurality of blue LED elements surface-mounted is attached to a heat radiating part 12 as a base part. The heat radiating part 12 radiates heat from the blue LED elements on the LED module 11A. The yellow phosphor 22 is applied to a globe 14, the LED module 11A is covered with the globe 14 applied with the yellow phosphor 22 and light emitted from the blue LED elements is converted to white light through the yellow phosphor 22 and radiated to the outside. A base 16 is attached to the heat radiating part 12 on the opposite side of the globe 14 and is electrically connected to a lighting circuit for lighting the blue LED elements. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an LED bulb and a lighting fixture that use an LED module on which a plurality of blue LED elements are surface-mounted as a light source.

  Due to the improvement of the light emission efficiency of light emitting diodes (LEDs), LED bulbs such as light bulb shaped lamps and lighting units that employ LEDs as light sources for general illumination or decoration have been commercialized. In particular, the development of an integrated LED bulb with a bulb cap for replacement of a bulb, an LED arranged in a glass bulb, and a lighting circuit inside is developed (for example, see Patent Document 1). . In this case, when obtaining white light, a blue LED element is used as a light source to obtain white light through a yellow phosphor. Therefore, a blue LED element is sealed with a sealing body, and a yellow phosphor is integrally formed in the vicinity of the blue LED element.

  FIG. 7 is a front view showing an example of an LED bulb having a light source of an LED module in which a plurality of blue LED elements and a yellow phosphor are integrally formed. The LED module 11 on which a plurality of LEDs are surface-mounted is attached in contact with the heat radiating plate 13 of the heat radiating portion 12. Moreover, the globe 14 is attached to the heat radiating plate 13 of the heat radiating portion 12 so as to cover the LED module 11, and the emitted light from the LED of the LED module 11 is emitted to the outside. On the other hand, a cap 16 is attached to the opposite side of the heat dissipation portion 12 from the globe 14 via an insulating member 15. The inside of the heat radiating portion 12 is hollow, and a lighting circuit for lighting the LED is incorporated in the hollow portion of the heat radiating portion 12. The heat of the LED of the LED module 11 passes through the heat radiating plate 13 and is transferred to the outer surface of the heat radiating portion 12 to be radiated.

  FIG. 8 is a block diagram of the LED module 11 of the LED bulb shown in FIG. In the LED module 11, a plurality of blue LED elements 19 are surface-mounted on one surface of a flat rectangular parallelepiped substrate 18, and wiring 20 is drawn from a side surface portion. And the coating layer 21 which consists of transparent resin is formed in the front part of the blue LED element 19, and the yellow fluorescent substance 22 is disperse | distributed in this coating layer 21. FIG. The yellow phosphor 22 emits light from the blue LED element 19 through the yellow phosphor 22 to obtain white light as the LED module 11. The LED module 11 is disposed on the heat radiating plate 13 of the heat radiating unit 12 with the surface on which the blue LED element 19 of the LED module 11 is surface-mounted facing the globe 14 side.

On the other hand, as an LED bulb in which an LED is sealed with a sealing member and a paint containing a phosphor is applied in the vicinity of the LED, the LED is placed in a glass bulb that is evacuated and sealed, and the phosphor layer is made of glass. There is one in which a phosphor layer is baked and components other than the phosphor are removed in a process before being applied to the inner surface of the bulb and combined with the LED (see, for example, Patent Document 2). As a result, deterioration of the sealing member and phosphor are suppressed, and a decrease in transmittance and color shift due to coloring are suppressed.
JP 2006-313717 A Japanese Patent Laid-Open No. 2005-5546

  However, in the case of the LED light bulb intended for the replacement of the light bulb in Patent Document 1, even if a plurality of power LEDs are used as the light source, for example, it is about several watts, and it is not easy to ensure the brightness of the light bulb. In order to obtain a light distribution like a general light bulb and maintain the illuminance, it is necessary to employ a plurality of LEDs to illuminate the entire lamp. In such a case, the number of LEDs increases and becomes expensive.

  In the LED bulb shown in FIG. 7, the blue LED element is sealed with a sealing body, and the yellow phosphor is integrally formed on the front surface of the blue LED element. It diffuses with the yellow phosphor and the extraction efficiency of white light from the LED module is lowered. Moreover, the heat dissipation of the blue LED element is inhibited by the yellow phosphor, the temperature of the LED module 11 rises, and the conversion efficiency of the yellow phosphor into white light decreases. As a result, the luminous efficiency of the LED module decreases.

  On the other hand, in the thing of patent document 2, since the fluorescent substance layer is apply | coated to the inner surface of a glass bulb, degradation of the fluorescent substance by the heat | fever from LED can be suppressed, and the ultraviolet-ray generated from LED is hardly lost. Since it reaches the phosphor layer, it is difficult to be affected by the surrounding environment, but since it does not employ a plurality of LEDs, there is no consideration for a decrease in luminous efficiency due to heat from the LEDs.

  An object of the present invention is to use an LED module in which a plurality of blue LED elements are surface-mounted as a light source, and to obtain white light through a yellow phosphor, heat from the plurality of blue LED elements can be efficiently dissipated, thereby improving luminous efficiency. It is to provide an enhanced LED bulb and luminaire.

  An LED bulb according to a first aspect of the present invention is an LED module in which a plurality of blue LED elements are surface-mounted; a base portion to which the LED module is attached; a yellow phosphor is applied and the LED module is covered A globe attached to the base portion for converting the emitted light from the blue LED element into white light through the yellow phosphor and emitting it to the outside; a lighting circuit provided in the base portion for lighting the blue LED element; A base provided at an end of the base portion on the opposite side of the globe and electrically connected to the lighting circuit.

  In the present invention and the following inventions, definitions and technical meanings of terms are as follows.

  The LED module refers to a light source unit in which a plurality of blue LED elements are surface-mounted on one surface of a flat rectangular parallelepiped. The LED module is disposed on the base portion with the surface of the LED module on which the blue LED element is surface-mounted facing outward. The base portion radiates heat of the LED, and for example, a metal member having good thermal conductivity is preferably used.

  The yellow phosphor refers to a yellow phosphor that converts emitted light from a blue LED element into white light. The yellow phosphor is applied to the inner surface or the outer surface of the globe, covers the LED module, converts the emitted light from the blue LED element into white light with the yellow phosphor, and emits it to the outside. The base is a connecting part for connecting to a power source, and the base is provided on the opposite side of the base part from the globe. Moreover, the lighting circuit which lights a blue LED element is arrange | positioned in the hollow part formed in the base | substrate part, for example, and is electrically connected to a nozzle | cap | die.

  The LED bulb according to the invention of claim 2 is characterized in that, in the invention of claim 1, the globe is subjected to diffusion processing.

  Diffusion processing refers to a process for diffusing light. For example, it means that silica is applied to the outer surface of the globe or the outer surface of the globe is shaved. By this diffusion processing, the color of the yellow phosphor applied to the globe when the blue LED element is turned off is relaxed.

  According to a third aspect of the present invention, there is provided an LED bulb according to the first aspect of the present invention, wherein the light bulb is diffused and disposed so as to cover the outside of the globe, and diffuses light emitted from the globe to the outside. It has a diffusion glove that emits light.

  In the present invention, the glove has a two-layer structure of an inner glove coated with a phosphor and a diffusion glove. By providing the diffusion globe, the color of the yellow phosphor applied to the inner globe when the blue LED element is turned off is relaxed.

  The LED bulb according to a fourth aspect of the invention is characterized in that, in the invention according to any one of the first to third aspects, a radiating fin is disposed on the outer surface of the base portion.

  A lighting fixture according to a fifth aspect of the invention includes the LED bulb according to any one of the first to fourth aspects; and a fixture main body to which the LED bulb is mounted.

  According to the first aspect of the present invention, the yellow phosphor is applied to the globe, and the plurality of blue LED elements surface-mounted on the LED module as the light source unit and the yellow phosphor are separated. Light from the element can be prevented from diffusing with the yellow phosphor. Therefore, heat dissipation of the LED module can be promoted, and the light emission efficiency of the LED module can be improved.

  According to the invention of claim 2, since the globe can be diffused to diffuse the external light applied to the globe, the color of the yellow phosphor applied to the globe when the blue LED element of the LED module is turned off can be adjusted. It can be relaxed and the appearance of the glove can be improved.

  According to the invention of claim 3, by providing the diffusion glove, the color of the yellow phosphor applied to the inner glove when the blue LED element of the LED module is turned off is alleviated, and the appearance of the entire glove is improved. Can be better.

  According to the invention of claim 4, heat radiation is further promoted by providing the heat radiation fins.

  According to invention of Claim 5, the lighting fixture which has an effect in any one of Claims 1 thru | or 4 can be provided.

  FIG. 1 is a front view showing an example of an LED bulb according to an embodiment of the present invention. In this embodiment, the yellow phosphor 22 is applied to the globe 14 to separate the blue LED element and the yellow phosphor 22 of the LED module 11A that is the light source unit from the conventional example shown in FIG. is there. The same elements as those in FIG.

  The LED module 11 </ b> A is an LED module in which a plurality of blue LED elements not integrally formed with a yellow light emitter are surface-mounted, and emits blue light by light emission of the blue LED elements. The LED module 11A is attached in contact with the heat radiating plate 13 of the heat radiating portion 12 as a base portion, and the globe 14 is attached to the heat radiating plate 13 of the heat radiating portion 12 so as to cover the LED module 11A. A yellow light emitter 22 is applied to the inner surface of the globe 14, and blue light from the blue LED element of the LED module 11 </ b> A is converted into white light by the yellow light emitter 22, and white light is emitted to the outside of the globe 14.

  In addition, although the external shape of the globe 14 is substantially spherical, a shape having a spheroid shape in part may be employed. When this spheroid-shaped globe is used, if the rotator shape is such that the central axis of the LED bulb is the axis of rotation and the minor axis of the ellipse is located on this axis of rotation, it is placed on the side of the LED bulb. Since light spreads, it is advantageous when applied to a lighting device such as a downlight in which an LED bulb is placed horizontally (horizontally arranged).

  On the other hand, an insulating member 15 made of synthetic resin is provided on the side of the heat radiating portion 12 opposite to the globe 14, and a base 16 is attached via the insulating member 15. The inside of the heat radiating portion 12 is hollow, and a lighting circuit for lighting the blue LED element is incorporated in the hollow portion of the heat radiating portion 12. A plurality of heat radiation fins 17 are provided on the side surface of the heat radiation portion 12, and heat of the blue LED element of the LED module 11 </ b> A is transferred to the plurality of heat radiation fins 17 through the heat radiation plate 13 and is radiated from the plurality of heat radiation fins 17. Is done.

  FIG. 2 is a block diagram of the LED module 11A of the LED bulb shown in FIG. The LED module 11 </ b> A is configured such that a plurality of blue LED elements 19 are surface-mounted on one surface of a flat rectangular parallelepiped substrate 18, and wiring 20 is drawn from a side surface portion. The LED module 11A is disposed on the heat dissipation plate 13 of the heat dissipation portion 12 with the surface of the LED module 11A on which the blue LED element 19 is surface-mounted facing the globe 14 side.

  FIG. 3 is a graph of test data of the LED bulb according to the embodiment of the present invention shown in FIG. 1 and the conventional LED bulb shown in FIG. Curve S1 shows the luminous flux of the LED bulb according to the embodiment of the present invention, and curve S2 shows the luminous flux of the conventional LED bulb.

  An LED bulb (blue LED element module 11A / yellow phosphor globe system) according to an embodiment of the present invention and a conventional LED bulb (white LED module 11 / silica globe system) were prepared. That is, as the test LED module, an aluminum substrate having a size of about 23 mm and a middle chip 30p (30 LEDs) arranged as an LED was prepared. And one prepared the blue LED element module 11A (no yellow phosphor) and the other prepared the white LED module 11 (with the yellow phosphor), and the blue LED element module 11A and the white LED module 11 were turned on simultaneously.

  When the luminous flux from the globe 14 at the time of lighting is measured and compared, when the luminous flux of the LED bulb according to the embodiment of the present invention is 100%, the luminous flux of the conventional LED bulb is about 80%. This is because in the white LED module 11 of the conventional LED bulb, part of the light from the blue LED element is diffused by the yellow phosphor 22, and the extraction efficiency of the white light from the LED module 11 is reduced. Is done. As described above, when the temperature characteristics are not taken into consideration (immediately after lighting), it is confirmed that the LED bulb according to the embodiment of the present invention has a luminous efficiency approximately 20% higher than that of the conventional LED bulb.

  Next, in order to know the temperature characteristics, the substrate temperature and the luminous flux of the blue LED element module 11A and the white LED module 11 were measured. As a result, the substrate temperature of the white LED module was about 90 ° C. and the substrate temperature of the blue LED element module was about 65 ° C. after 10 minutes of lighting. The luminous flux was about 80% for the white LED module and about 97% for the blue LED element module, respectively, compared with the luminous flux immediately after lighting. In the case of a white LED module, the yellow phosphor is integrally formed in the vicinity of the blue LED element, the heat dissipation of the blue LED element is hindered by the yellow phosphor, and the temperature of the white LED module 11 rises to yellow. It is determined that the conversion efficiency of the phosphor to white light is reduced.

  As described above, when the temperature characteristics are taken into consideration, the LED bulb according to the embodiment of the present invention has a luminous efficiency approximately 1.5 times that of the conventional LED bulb {97% / (80% × 80%) } Was confirmed.

  Here, in the embodiment of the present invention shown in FIG. 1, since the yellow phosphor is applied to the globe 14, the color of the yellow phosphor 22 applied to the globe 14 is such that the blue LED element module 11A is turned off. Sometimes it stands out and some people feel uncomfortable. Therefore, diffusion processing such as frost treatment is performed on the outer surface of the globe 14 to relieve the color of the yellow phosphor applied to the globe when the blue LED element is turned off.

  The diffusion process only needs to be a process for diffusing light. For example, silica is applied to the outer surface of the globe 14, or the outer surface of the globe is roughened to diffuse the external light to the globe 14, The color of the yellow phosphor applied to the globe 14 when the blue LED element is turned off is alleviated. Moreover, you may make it give the functional film which produces a glittering feeling like the translucent optical thin film in which the fine reflective material was mixed in the globe 14. FIG.

  FIG. 4 is a front view showing another example of the LED bulb according to the embodiment of the present invention. In this example, the globe has a substantially spherical shape and is coated with a yellow phosphor on the inner surface, but is composed of a polyhedron with a minute facet plane (polygon) formed on the outer surface.

  As described above, since the outer surface of the globe is a small polyhedron, the color of the phosphor applied to the globe generated when the light is extinguished can be relaxed. In addition, since the iridescent color dispersed in the minute polygon is raised on the outer surface of the globe due to the prism effect of the polyhedron, it is possible to produce a high-class feeling of the LED bulb.

  In addition, although the drawing shows a polyhedron composed of minute facet planes, it may be a quasi-regular polyhedron (cut corner icosahedron) composed of a regular pentagon and a regular hexagon, or other combinations of equilateral triangles. Or, it may be a combination of different shapes, such as a brilliant cut.

  Further, as shown in FIG. 5, the globe 14 has a two-layer structure of an inner globe 14A and a diffusion globe 14B, a yellow phosphor 22 is applied to the inner globe 14A, and the inner globe 14A has an inner side outside the inner globe 14A. A diffusion glove 14B that does not apply the yellow phosphor 22 may be provided so as to cover the globe 14A, and the color of the yellow phosphor applied to the inner globe 14A when the blue LED element is turned off may be alleviated. .

  According to these examples of the embodiment of the present invention, the yellow phosphor 22 is applied to the globe 14 to separate the blue LED element 19 and the yellow phosphor 22 of the LED module 11A that is the light source unit. The light from the blue LED element 19 of the module 11A can be prevented from diffusing by the yellow phosphor 22. Therefore, the luminous efficiency can be improved, and the heat radiation of the LED module 11A can be promoted.

  Further, when the globe 14 is subjected to diffusion processing, the external light irradiated on the globe 14 can be diffused, so that the yellow phosphor 22 applied to the globe 14 when the blue LED element 19 of the LED module 11A is turned off. Can be relaxed and the appearance of the globe 14 can be improved.

  Further, the globe 14 has a two-layer structure of an inner globe 14A and a diffusion globe 14B, a yellow phosphor 22 is applied to the inner globe 14A, and the diffusion globe 14B is provided so as to cover the inner globe 14A. The color of the yellow phosphor applied to the inner globe 14A when the blue LED element 19 of the module 11A is turned off can be relaxed. Thereby, the appearance of the entire glove can be improved.

  FIG. 6 is a front view showing still another example of the LED bulb according to the embodiment of the present invention. In this example, the radiation fins 17 extend along the substantially spherical globe 14 to the vicinity of the maximum diameter portion of the globe 14. According to such a heat radiating fin 17, the heat radiating area of the heat radiating fin 17 is increased, the heat radiating effect can be increased, and a decrease in the amount of light emitted from the globe 14 can be suppressed.

  When trying to realize an LED bulb instead of a mini krypton bulb, ensure that the LED chip for obtaining the required optical performance and a sufficient heat sink to radiate the heat generated from the phosphor are within the size of the mini krypton bulb. It is not easy. First, the luminous flux of the mini-krypton bulb is 500 lm for the 40 W type and 800 lm for the 60 W type, and this requires an input power of 5 to 10 W. On the other hand, the heat sink for dissipating the amount of electric power requires an area extending from the base 16 to not only the neck portion of the globe 14 but also the spherical portion of the globe 14 which is a light emitting portion.

  However, in this case, since the portion that is the original light emitting portion becomes a non-light emitting portion, there arises a problem that the light distribution is different from that of the mini-krypton bulb. A normal light bulb has a light distribution of approximately 360 ° radially except for the base portion. However, in an extreme example, if the heat sink is made up to the vicinity of a half of a spherical shape, the base half of the light bulb becomes a non-light emitting part. Therefore, the light distribution is about 180 °. In the case of this krypton bulb, the lighting direction when it is incorporated into a lighting fixture is not necessarily vertically downward, but varies in various ways, such as sideways and diagonally downward. Therefore, if the light distribution of the light bulb is different, the light distribution when the light bulb is incorporated in the lighting fixture will be different and cannot be replaced.

  However, in the case of this example, light radiation of the light emitting part on the base side is not largely blocked by the heat radiation fins 17 as heat sinks, so that almost the same light distribution as that of the mini-krypton bulb can be realized. In addition, you may connect the front-end | tip part of this radiation fin 17 and the inside of a globe spatially. For example, a hole facing the tip portion of the radiating fin 17 may be formed in the globe 14, and the tip of the radiating fin 17 may be inserted into this hole to achieve spatial connection.

  Thus, by inserting the radiation fins 17 inside the globe, it becomes possible to reduce the temperature of the circuit board during the lighting of the LED bulb by 10 ° C. Instead of inserting the radiating fins 17 inside the globe, a metal mesh that is thermally connected to the radiating fins 17 may be covered so as to cover the entire globe so that the mesh acts as a radiating portion. Thus, by arranging the mesh, the heat radiation area can be increased, and the light emission of the globe 14 is not impaired.

The front view which shows an example of the LED bulb which concerns on embodiment of this invention. The block diagram of the LED module of the LED bulb shown in FIG. The graph of the test data of the LED bulb of embodiment of this invention shown in FIG. 1 and the LED bulb of the prior art example shown in FIG. The front view which shows another example of the LED bulb which concerns on embodiment of this invention. The front view which shows another example of the LED bulb which concerns on embodiment of this invention. The front view which shows another another example of the LED bulb which concerns on embodiment of this invention. The front view which shows an example of the conventional LED bulb which uses as a light source the LED module which integrally formed several blue LED element and yellow fluorescent substance. The block diagram of the LED module of the LED bulb shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... LED module, 12 ... Radiation part, 13 ... Radiation plate as base | substrate part, 14 ... Globe, 15 ... Insulation member, 16 ... Base, 17 ... Radiation fin, 18 ... Substrate, 19 ... Blue LED element, 20 ... Wiring , 21 ... coating layer, 22 ... yellow phosphor

Claims (5)

An LED module on which a plurality of blue LED elements are surface-mounted;
A base portion to which the LED module is attached;
A glove that is coated with a yellow phosphor, covers the LED module, is attached to a base portion, converts the emitted light from the blue LED element into white light through the yellow phosphor, and emits the light to the outside;
A lighting circuit that is provided in the base portion and lights the blue LED element;
A base provided at an end of the base portion opposite to the globe and electrically connected to the lighting circuit;
LED bulb characterized by comprising.   The LED bulb according to claim 1, wherein the globe is subjected to diffusion processing.   The LED according to claim 1, further comprising a diffusion glove that is diffused and disposed so as to cover an outer side of the globe, and that diffuses light emitted from the globe and emits the light to the outside. light bulb.   The LED bulb according to any one of claims 1 to 3, wherein a radiation fin is disposed on an outer surface of the base portion. An LED bulb according to any one of claims 1 to 4;
An instrument body equipped with this LED bulb;
The lighting fixture characterized by comprising.

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