JP2013191685A - Light-emitting device and luminaire using the same - Google Patents

Abstract

In a light emitting device using a plurality of types of LEDs, heat of a wavelength conversion unit containing a phosphor is efficiently radiated.
A light emitting device includes a plurality of types of light emitting units having different emission colors, a substrate on which the light emitting units are mounted, and a translucent cover that is provided in common to the light emitting units. . Each of the light emitting units 2 includes the same type of LED 21 and wavelength conversion units 22R, 22G, and 22B (generically named) that convert the wavelengths of the light emitted from the LEDs 21 to different wavelengths between the light emitting units 2 by covering the LEDs 21, respectively. 22). The translucent cover 7 is in contact with the light emitting surface of each wavelength conversion unit 22 in common and radiates heat generated from the LED 21 and the wavelength conversion unit 22. According to this configuration, even if there is a difference in output of the light emitting unit 2 or a difference in heat generation characteristics of the phosphor, heat can be efficiently diffused and radiated by the translucent cover 7. Therefore, temperature variations between the light emitting units 2 are less likely to occur, and color unevenness of the irradiation light of the lighting device 1 can be suppressed.
[Selection] Figure 3

Description

  The present invention relates to a light emitting device including a plurality of solid state light emitting elements and an illumination device using the same.

  Light emitting diodes (LEDs) can emit light with high power and high luminance, and are used as light sources for various electric devices such as displays and lighting equipment. In recent years, in addition to red LEDs and green LEDs, blue LEDs have been put into practical use. By combining these RGB three-color LEDs, or combining LEDs with phosphors that convert the wavelength of light emitted from the LEDs, there are various types of LEDs. Light color can be emitted.

  However, it is known that the conversion efficiency of the phosphor decreases as the ambient temperature increases. Therefore, when the phosphor is exposed to light of a long period or high output due to light emission of the LED, not only the light emission efficiency is lowered, but also the light emission wavelength is changed, and the light color may be changed. In particular, in recent years, light emitting devices using LEDs have been used as light sources for lighting fixtures, and the output of light emitting devices has been increasing, and the load on the phosphor has also increased. Therefore, it is necessary to suppress the temperature rise around the phosphor in order to ensure the reliability of the light emitting device.

  Therefore, a light emitting device is known in which a conductor wiring is patterned on an insulating heat dissipation member, and an LED is flip-chip mounted thereon, so that heat from the LED is efficiently radiated (for example, , See Patent Document 1).

JP 2008-16583 A

  However, when the wavelength of the light emitted from the LED is converted, the phosphor is excited to generate heat. However, although the light emitting device described in Patent Document 1 can effectively dissipate the heat of the LED, it is not suitable for dissipating the heat of the phosphor contained in the wavelength conversion unit.

  In addition, in a lighting device in which the chromaticity of irradiated light is variable using a plurality of types of LED light emitting units having different emission colors, the temperature varies depending on the output difference of the LED light emitting unit and the heat generation characteristics of the phosphor. Is likely to occur. For this reason, in such a light emitting device using a plurality of types of LED light emitting units, there is a possibility that the chromaticity of the irradiation light does not become the set chromaticity or color unevenness occurs.

  This invention is made | formed in view of the said subject, In the structure using several types of LED light emission part from which luminescent color differs, it can thermally radiate | emit the heat | fever of the wavelength conversion part containing a fluorescent substance efficiently. An object of the present invention is to provide a light-emitting device that can be used and a lighting device using the same.

  In order to solve the above problems, a light emitting device according to the present invention is commonly used for a plurality of types of light emitting units having different emission colors, a substrate on which the plurality of types of light emitting units are mounted, and the plurality of types of light emitting units. Each of the plurality of types of light-emitting portions each covering the same type of solid-state light-emitting element and the solid-state light-emitting element, and changing the wavelength of light emitted from each solid-state light-emitting element. A wavelength converting unit that converts the light emitting units to wavelengths different from each other, and the translucent cover is in common contact with a light emission surface of the plurality of types of wavelength converting units, and the solid-state light emitting element and the wavelength converting unit The heat generated from the part is dissipated.

  In the light-emitting device, the translucent cover is preferably made of a glass material.

  The light emitting device may further include a case that accommodates the plurality of types of light emitting units, the substrate, and the translucent cover, and the case is formed of a material having high thermal conductivity, and the periphery of the translucent cover It is preferable to contact.

  In the light emitting device, the plurality of types of light emitting units include a red light emitting unit that emits red light, a green light emitting unit that emits green light, and a blue light emitting unit that emits blue light, and the red light emitting unit. The part is preferably mounted at a position closer to the periphery of the substrate than the green light emitting part and the blue light emitting part.

  In the light emitting device, it is preferable that the translucent cover covers the entire surface of the light emitting surface of the plurality of types of wavelength conversion units and the surface on which the light emitting unit of the substrate is mounted.

  The light emitting device is preferably used for a lighting device.

  According to the present invention, even if there is a difference in output of the light emitting part or a difference in heat generation characteristics of the phosphor, heat can be efficiently diffused and radiated by the translucent cover in contact with the wavelength conversion member. Therefore, temperature variations between the light emitting portions are less likely to occur, and color unevenness of the irradiated light can be suppressed.

The block diagram of the light-emitting device which concerns on one Embodiment of this invention. The partially exploded perspective view of the light-emitting device. FIG. 3 is a side sectional view taken along line AA in FIG. 2. FIG. 3 is a side sectional view showing a configuration in which the light emitting device is applied to a lighting device. The partially exploded perspective view of the light-emitting device which concerns on the modification of the said embodiment. FIG. 6 is a side sectional view taken along line AA in FIG. 5.

  A light emitting device according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the light emitting device 1 of the present embodiment includes a plurality of types of light emitting units 2 using solid light emitting elements (hereinafter referred to as LEDs) as light sources, and a chromaticity setting unit 3 that sets a predetermined chromaticity. And a control unit 4 that adjusts the light output of the light emitting unit 2 to the chromaticity set by the chromaticity setting unit 3. In the present embodiment, the light emitting unit 2 includes at least three light emitting units each configured to emit light having different chromaticities, here, a red light emitting unit 2R that emits red light, and a green light emitting unit that emits green light. A configuration in which three types of 2G and a blue light emitting unit 2B that emits blue light are used is shown. In the following description, these three types of light emitting units 2R, 2G, and 2B are simply referred to as the light emitting unit 2 when the light color is not particularly limited.

  A plurality of each light emitting unit 2 is mounted on the substrate 5 as a package. In the illustrated example, four red light emitting units 2R and four green light emitting units 2G and five blue light emitting units 2B are used, but the number of each light emitting unit 2 is not limited to this example, Four or more types of light emitting units 2 may be used. Wiring circuits 51R, 51G, and 51B are formed on the substrate 5 so that LEDs used in the light emitting unit 2 of the same type are connected in series.

  The chromaticity setting unit 3 includes a volume controller 31 for setting the color temperature of the emitted light of each light emitting unit 2, that is, the color temperature of the irradiation light of the light emitting device 1 to a predetermined value. The volume controller 31 switches the light emitting device 1 from the off state to the on state by a rotation operation of the knob by the user, and changes the light output of the light emitting device 1 according to the rotation range. Further, the volume controller 31 emits light of a low color temperature while the light emitting device 1 is in the on state and the light output is small, and further increases the light output by further rotating the knob, and gradually decreases. A light control operation for irradiating light with a color temperature higher than the color temperature is enabled.

  When a predetermined color temperature is input by the volume controller 31, the chromaticity setting unit 3 causes the chromaticity on the black body radiation locus at the input color temperature, that is, the equal color temperature on the chromaticity diagram at this color temperature. The intersection coordinates of the line and the black body radiation locus are set to the set chromaticity (hereinafter, set chromaticity). Further, the chromaticity setting unit 3 outputs a duty signal including control information on the set chromaticity to the control unit 4.

  The control unit 4 is incorporated in a power supply unit (not shown) for lighting the light emitting device 1, and has a plurality of output terminals (in the example shown, outputs R, G, B) corresponding to the type of package of each light emitting unit 2. Is provided. The control unit 4 receives power from a commercial power source (not shown) and converts it into a predetermined direct current, and also emits light from the light emitting units 2R, 2G, and so on corresponding to the duty signal from the chromaticity setting unit 3. It has a rectification transformer circuit (not shown) for controlling the voltage to be applied for dimming control of 2B. Each output (terminal) R, G, B is connected to wiring circuits 51R, 51G, 51B by wiring 41R, 41G, 41B, respectively.

  As shown in FIGS. 2 and 3, the light emitting device 1 further includes a frame body 6 that holds the substrate 5 and a translucent cover 7 that is provided in common to the respective light emitting units 2. The frame body 6 is a bottomed cylindrical structural member having an opening on one surface, and is formed of a resin material or the like that is enhanced in thermal conductivity by adding a metal material or filler that has high thermal conductivity.

  Each of the light emitting units 2 includes the same type of LEDs 21 and wavelength conversion units 22R, 22G, which cover these LEDs 21 and convert the wavelengths of light emitted from the LEDs 21 to different wavelengths between the light emitting units 2, respectively. 22B (collectively 22). The LEDs 21 have the same luminescent color, and a general-purpose nitride semiconductor that emits light in the near ultraviolet to blue wavelength region is preferably used. If the same type of LED 21 is used for each light emitting unit 2, component procurement costs can be reduced. Moreover, the color temperature of irradiation light can be changed in a wide range by changing the arrangement and number of the wavelength conversion units 22R, 22G, and 22B.

The translucent resin material contains a phosphor that converts the wavelength of the emitted light from the LED 21, and the phosphor-containing resin material is coated on the emitting surface of the LED 21. At this time, a red phosphor (for example, CASN phosphor (CaAlSiN ₃ : Eu, etc.)) that converts the wavelength of the light emitted from the LED 21 into light in the red wavelength region is used for the red light emitting unit 2R. A green phosphor (for example, a CSO phosphor (CaSc ₂ O ₄ : Ce, etc.)) that converts the wavelength of light emitted from the LED 21 into light in the green wavelength region is used for the green light emitting unit 2G. If the LED 21 itself used emits blue light and the chromaticity of the blue light is within a predetermined chromaticity range, the phosphor is not necessarily required for the blue light emitting unit 2B. Further, if the LED 21 emits near-ultraviolet to violet light, a blue phosphor (for example, BAM: Eu, Mn phosphor or the like) that converts the wavelength of the emitted light of the LED 21 into light in the blue wavelength region is used. . On the other hand, even if the LED 21 itself emits blue light, if the chromaticity of the blue light is not within a predetermined chromaticity range, a blue phosphor for chromaticity adjustment is used.

  In each of the light emitting units 2 configured as described above, the blue light emitting unit 2B is disposed in a substantially central region of the substrate 5, and the green light emitting unit 2G and the blue light emitting unit 2B are disposed in the vicinity thereof. Preferably, the red light emitting unit 2R is mounted at a position closer to the periphery of the substrate 5 than the green light emitting unit 2G and the blue light emitting unit 2B.

  The translucent cover 7 is in common contact with the light emitting surfaces of the wavelength conversion units 22R, 22G, and 22B, and dissipates heat generated from the LEDs 21 and the wavelength conversion units 22R, 22G, and 22B. The translucent cover 7 is fitted into the opening of the frame body 6 so as to be in contact with the light emitting surface of each of the wavelength conversion units 22R, 22G, and 22B, a collar portion 72 provided on the periphery of the cover main body 71, Have The flange 72 is in contact with the opening edge of the frame 6 and holds the translucent cover 7 so that a predetermined gap is formed between the surface of the cover body 71 on the light emitting unit 2 side and the substrate 5. Further, the flange 72 is formed so that the outer diameter thereof matches the outer diameter of the frame body 6. The translucent cover 7 is made of a glass material having high thermal conductivity.

The substrate 5 is a substrate for a general-purpose light emitting module. For example, a metal oxide (including ceramics) having electrical insulating properties such as aluminum oxide (Al ₂ O ₃ ) or aluminum nitride (AlN), a metal nitride, Or it is comprised from materials, such as a metal, resin, and glass fiber. The wiring circuit 51 (see FIG. 1) formed on the substrate 5 is covered with an insulating material and connected to the positive and negative electrodes of the LEDs 21 of the light emitting unit 2 and connected to the wirings 41R, 41G, and 41B. Are exposed as electrode terminals (not shown).

  The LED 21 is provided with an electrode terminal (not shown) on the side opposite to the light emitting surface, and is flip-chip mounted on a wiring circuit 51 formed on the substrate 5. The substrate 5 on which the LED 21 is mounted is attached to the frame body 6, and in this state, a translucent resin containing various phosphors is applied onto the light emitting surface of the LED 21 by a dispenser or the like. The application amount is set in consideration of the interval between the plurality of LEDs 21 and the height of the gap formed between the substrate 5 and the translucent cover 7. Then, the translucent cover 7 is fitted into the opening of the frame 6 before the translucent resin is cured. At this time, the translucent resin is crushed by the translucent cover 7 and cured in a state where the upper surface thereof is flat. Thereby, the substantially frustoconical wavelength converter 22 whose upper surface (light emitting surface) is in contact with the translucent cover 7 is formed. In addition, although you may mount LED by wire bonding using LED with which the electrode terminal was provided in the light emission surface side, in this case, the length and the bending are carried out so that a wire may not contact translucent cover 7. It needs to be controlled accurately.

  According to this configuration, the heat of the phosphor of the wavelength conversion unit 22 is transmitted to the translucent cover 7 and is radiated to the atmosphere and the frame 6, so that the temperature increase of the wavelength conversion unit 22 can be suppressed. . As a result, the function deterioration of the wavelength conversion characteristic of the phosphor included in the wavelength conversion unit 22 is suppressed, and the chromaticity of the irradiation light can be set to a desired chromaticity. In addition, since the translucent cover 7 is in contact with each light emitting unit 2, heat is diffused by the translucent cover 7 even if there is a difference in output of the light emitting unit 2 or a difference in heat generation characteristics of the phosphor. As a result, temperature variations between the light emitting units 2 are less likely to occur, and color unevenness of the irradiation light of the lighting device 1 can be suppressed.

  The red light emitting unit 2R is mounted at a position closer to the periphery of the substrate 5 than the green light emitting unit 2G and the blue light emitting unit 2B. In general, the wavelength conversion efficiency of red phosphors is likely to decrease due to temperature rise. On the other hand, according to the said structure, since the heat | fever of a red fluorescent substance is easy to be electrically heated from the translucent cover 7 to the frame 6, the temperature rise of a red fluorescent substance can be suppressed more efficiently. As a result, even when the red light emitting unit 2R is controlled to be lit for a long time, it is possible to suppress the deterioration of the function of the red phosphor, and the chromaticity of the irradiation light can be set to a desired chromaticity over a long period. .

  When the light emitting device 1 is used as a lighting device, a case 8 that accommodates each light emitting section 2, the substrate 5, and the translucent cover 7, and a die cast 9 that holds the frame 6 and the case 8 are provided. The case 8 is a cylindrical member formed so that the inner periphery thereof is in contact with the outer periphery of the frame body 6 and the translucent cover 7, and is formed of a material having high thermal conductivity, like the frame body 6. That is, the inner periphery of the case 8 is in contact with the peripheral edge of the translucent cover 7. The die-cast 9 is made of a metal such as aluminum having a high heat dissipation property, and a plurality of fins are provided in order to improve the heat dissipation property. According to this configuration, the heat of the wavelength conversion unit 22 can be radiated more efficiently through the translucent cover 7, the case 8, and the die cast 9. 3 and 4, the heat radiation direction is indicated by a dotted arrow.

  Next, a light emitting device according to a modification of the above embodiment will be described with reference to FIGS. In the light emitting device 1 of this modification, the translucent cover 7 covers the entire surface of the light emitting surface of the plurality of types of wavelength conversion units 22 and the surface on which the light emitting unit 2 of the substrate 5 is mounted. . Specifically, a recess 73 into which the wavelength conversion unit 22 is fitted is formed at a position corresponding to each LED 21 on the surface of the cover body 71 of the translucent cover 7 on the substrate 5 side.

  According to this modification, the contact area between the wavelength conversion unit 22 and the translucent cover 7 is increased, and the translucent cover 7 is also in contact with the substrate 5. Heat can be radiated more efficiently through the substrate 5.

  Further, in this modification, the recess 73 formed in the translucent cover 7 is filled with a translucent resin containing various phosphors, and the substrate 5 is placed here before the translucent resin is cured. The wavelength converter 22 can be formed by inserting the LED 22. When forming the wavelength conversion part 22 by apply | coating on LED21 as mentioned above, it was not easy to control the fluidity | liquidity of resin. That is, if the fluidity of the resin is too high, the resin may flow to the adjacent LED 21 when applied, and if the fluidity is too low, the adhesiveness with the translucent cover 7 may deteriorate. is there. On the other hand, according to this modification, the wavelength converter 22 can be easily formed regardless of the fluidity of the resin.

  In addition, this invention is not restricted to the said embodiment, A various deformation | transformation is possible. In the above embodiment, a configuration using three types of light emitting units of blue, green, and red is shown. For example, a white light emitting unit using a so-called white LED in which a blue phosphor is coated with a yellow phosphor is further added. May be. As the white LED, for example, an LED unit conforming to LED chromaticity regulations (ANSI standards) defined in the United States is configured such that variations in chromaticity are within a predetermined range from a black body locus. Therefore, for example, in the light emitting device 1, for chromaticity that is frequently used, if an LED unit conforming to the above regulations is obtained from the market and used, the manufacturing efficiency of the light emitting device 1 is improved, and other light emitting units 2 are used. The load on the LED 21 can be reduced.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Light-emitting part 2R Red light-emitting part 2G Green light-emitting part 2B Blue light-emitting part 21 LED (solid-state light emitting element)
22R, 22G, 22B (22) Wavelength converter 4 Translucent cover 5 Substrate 8 Case

Claims (6)

A light emitting device comprising: a plurality of types of light emitting units having different emission colors; a substrate on which the plurality of types of light emitting units are mounted; and a translucent cover provided in common to the plurality of types of light emitting units. And
Each of the plurality of types of light emitting units includes the same type of solid state light emitting element and a wavelength that covers the solid state light emitting element and converts the wavelength of light emitted from each solid state light emitting element to a different wavelength between the respective light emitting units. A conversion unit,
The light-transmitting cover is in common contact with a light emitting surface of the plurality of types of wavelength conversion units, and dissipates heat generated from the solid light emitting element and the wavelength conversion unit.   The light-emitting device according to claim 1, wherein the translucent cover is made of a glass material. A case for accommodating the plurality of types of light emitting units, the substrate, and the translucent cover;
The light emitting device according to claim 1, wherein the case is made of a material having high thermal conductivity and is in contact with a peripheral edge of the translucent cover. The plurality of types of light emitting units include a red light emitting unit that emits red light, a green light emitting unit that emits green light, and a blue light emitting unit that emits blue light,
The light emission according to any one of claims 1 to 3, wherein the red light emitting unit is mounted at a position closer to a periphery of the substrate than the green light emitting unit and the blue light emitting unit. apparatus.   The said translucent cover has coat | covered the surface in which the light emission part of the said board | substrate and the light emission part of the said multiple types of wavelength conversion part are mounted, The one of Claim 1 thru | or 4 characterized by the above-mentioned. A light-emitting device according to claim 1.   An illumination device using the light emitting device according to any one of claims 1 to 5.

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