JP2011216868A - Light emitting device, and illumination apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device improving luminous efficiency, and allowing influence of change of an emission color depending on the temperature of a red light emitting LED element to be reduced by focusing attention on a temperature characteristic of the red light emitting LED element.SOLUTION: This light emitting device 1 is mounted to this illumination apparatus. The light emitting device 1 emits light having a correlated color temperature of 2,400 to 3,600 K, and includes a substrate 2, blue light emitting LED elements 3 and red light emitting LED elements 4 mounted on the substrate 2, and a wavelength converting unit 6. The red light emitting LED element 4 has a luminous intensity of 0.2 to 2.5 times as large as that of the blue light emitting LED element 3 at normal use temperature in a state mounted to the illumination apparatus. The wavelength converting unit 6 is excited by light emitted from the blue light emitting LED elements 3 and converts the light to light having a peak at a wavelength of 500-600 nm.

Description

  Embodiments described herein relate generally to a light emitting device using an LED element as a light source, and an illumination device including the light emitting device.

  In recent years, illumination devices equipped with light-emitting devices using LED elements as light sources have been proposed. In a light emitting device, a large number of LED element bare chips are mounted on a substrate, these LED chips are electrically connected by bonding wires, and a plurality of LED chips are sealed with a sealing body containing a phosphor. And it is trying to obtain light such as white, daylight, and light bulb.

  However, the light generated by such a light emitting device has a small reddish component, and it is difficult to obtain light of, for example, light bulb color with high color rendering properties.

  For this reason, it can be considered that the red component is compensated by sealing the blue light-emitting LED element with a sealing body containing a yellow phosphor and a red phosphor. However, the red phosphor has poor energy conversion efficiency and may cause a decrease in the light emission efficiency of the light emitting device.

  A light emitting device comprising: a blue light emitting LED element; a red light emitting LED element; and a phosphor that is excited by the blue light emitting LED element and emits light in an emission spectrum in a wavelength band between the blue light emitting LED element and the red light emitting LED element. A device has been proposed. In this light emitting device, a red light emitting LED element is used, and red light is directly emitted from the red light emitting LED element, whereby the light emission efficiency of the light emitting device is not lowered.

JP 2008-227212 A JP 2002-57376 A

  However, the red light-emitting LED element has a characteristic that a change in characteristics due to temperature is large. For example, the light-emitting color changes greatly according to a change in temperature.

  The problem to be solved by the present invention is a light emitting device capable of improving the light emission efficiency and focusing on the temperature characteristics of the red light emitting LED element and reducing the influence of the change in the light emission color due to the temperature of the red light emitting LED element. And an illumination device including the light emitting device.

  The light emitting device of the embodiment is a light emitting device that is attached to a lighting device and has a correlated color temperature of emitted light of 2400K to 3600K, and includes a substrate, a blue light emitting LED element and a red light emitting LED element mounted on the substrate, Wavelength conversion means is provided. The red light-emitting LED element has a light intensity of 0.2 to 2.5 times the light intensity of the blue light-emitting LED element at a normal use temperature in a state of being attached to the lighting device. The wavelength conversion means is excited by light emitted from the blue light emitting LED element and converts the light into light having a peak at a wavelength of 500 nm to 600 nm.

  ADVANTAGE OF THE INVENTION According to this invention, it can anticipate providing the light-emitting device which has favorable color rendering property, can improve luminous efficiency, and can reduce the influence of the change of the luminescent color by the temperature of a red light emitting LED element.

It is a perspective view which shows the light-emitting device of 1st Embodiment. It is sectional drawing shown along the XX line in FIG. In a light emitting device same as the above, it is a top view which shows the mounting state of a blue light emitting LED element and a red light emitting LED element in the state before forming a frame member and a sealing member. It is a top view which expands and shows the mounting state of a blue light emitting LED element and a red light emitting LED element same as the above. It is a table | surface which shows the measurement result of correlation color temperature same as the above, the luminous intensity of a blue light emitting LED element, and the luminous intensity ratio of a blue light emitting LED element and a red light emitting LED element. It is a table | surface which shows a measurement result of the correlation color temperature same as above, and the luminous intensity ratio of a blue light emitting LED element and a red light emitting LED element. It is a graph which shows the calculated value which calculated | required the lower limit and the upper limit of the ratio of the luminous intensity of a red light emitting LED element with respect to the luminous intensity of a blue light emitting LED element in correlation color temperature 2400K and 3600K based on a measurement result same as the above. It is a table | surface which shows the relationship between correlation color temperature same as the above, and the luminous intensity ratio of the red light emitting LED element with respect to a blue light emitting LED element. It is sectional drawing which shows an LED lamp as an illuminating device provided with the light-emitting device same as the above. It is a perspective view which shows a downlight as an illuminating device provided with the light-emitting device same as the above. It is a light emitting device concerning a 2nd embodiment, and is a top view showing the mounting state of a blue light emitting LED element and a red light emitting LED element in the state before forming a frame member and a sealing member. It is a light-emitting device of 3rd Embodiment, and is a top view which shows the mounting state of a blue light emitting LED element and a red light emitting LED element. It is a light-emitting device of 4th Embodiment, and is a top view which shows the mounting state of a blue light emitting LED element and a red light emitting LED element. It is a graph which shows the emission spectrum of the light-emitting device of 5th Embodiment. It is a graph which shows the emission spectrum of the light-emitting device of 6th Embodiment. It is a light emitting device same as the above, and is a top view which shows the mounting state of a blue light emitting LED element and a red light emitting LED element in the state before forming a frame member and a sealing member.

  Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 10. In addition, the same code | symbol is attached | subjected to the same part in each figure, and the overlapping description is abbreviate | omitted. 1 to 4 show the light emitting device 1, FIGS. 5 to 8 show the measurement results regarding the color temperature, and FIGS. 9 and 10 show the lighting device 41 provided with the light emitting device 1.

  As shown in FIGS. 1 and 2, a light emitting device 1 includes a substrate 2, a plurality of blue light emitting LED elements (hereinafter referred to as blue LEDs) 3 and red light emitting LED elements (hereinafter red LEDs) mounted on the substrate 2. 4), a frame member 5, and a sealing member 7 as wavelength converting means 6. That is, the light emitting device 1 employs a COB (Chip On Board) system in which a plurality of LEDs 3 and 4 are mounted on a substrate 2.

  As shown in FIGS. 1 to 3, the substrate 2 includes a base material 21, a mounting pad 22 and a power supply terminal 23 provided on the front surface side of the base material 21, and a metal provided on the back surface side of the base material 21. And a plate member 24. The mounting pad 22, the power feeding terminal 23, and the metal plate member 24 are made of, for example, a copper plate material and are directly bonded to the base material 21.

  The base material 21 is formed in a substantially rectangular shape with a flat plate made of a ceramic material such as white aluminum oxide, aluminum nitride, silicon nitride, or the like. As representatively shown in FIG. 3, a square mounting pad 22 on which the blue LED 3 and the red LED 4 are mounted is disposed in the center of the surface side of the base material 21. In addition, a pair of power supply terminals 23 are arranged on the surface side of the base material 21 on both sides of the mounting pad 22 with a predetermined spacing.

  On the other hand, a flat metal plate member 24 is joined to the back surface side of the substrate 21 over substantially the entire surface thereof. The metal plate member 24 has a function of heat dissipation and deformation prevention of the substrate 2.

  As the substrate 21, a metal substrate in which an insulating layer is laminated on one surface of a metal material having good thermal conductivity and excellent heat dissipation, such as aluminum, can be used. Further, when the base plate material is an insulating material, a synthetic resin material such as a glass epoxy resin can be applied.

  As shown in FIG. 2, the mounting pad 22 and the power supply terminal 23 have a three-layer configuration. A copper plate bonded on the surface of the base material 21 is a first layer A, and a second layer A is formed on the surface of the copper plate. The layer B is plated with nickel (Ni) and the third layer C is plated with silver (Ag). The third layer C, ie, the surface layer, of the mounting pad 22 is silver (Ag) plated, and the total light reflectance is as high as 90%.

  The blue LED 3 and the red LED 4 are bonded onto the mounting pad 22 using a silicone resin insulating adhesive 26.

  The blue LED 3 is composed of an LED chip that emits blue light having a wavelength of 450 nm to 470 nm, such as InGaN-based or GaN-based. Further, the blue LED 3 includes a light emitting layer that emits blue light on an element substrate such as a translucent sapphire, and has a pair of positive and negative element electrodes 27 that allow current to flow through the light emitting layer.

  The red LED 4 is composed of an LED chip that emits red light having a wavelength of 580 nm to 620 nm, such as an AlGalnP system or a GaAlAs mixed crystal system. Further, the red LED 4 includes a light emitting layer that emits red light on an element substrate such as a translucent sapphire, and has a pair of positive and negative element electrodes 28 that allow current to flow through the light emitting layer.

  These element electrodes 27 and 28 are electrically connected by a bonding wire 29. The bonding wire 29 is made of a fine gold (Au) wire and is connected to the device electrodes 27 and 28 via bumps mainly composed of gold (Au) in order to improve mounting strength and reduce damage to the LED chip. Has been.

  As shown mainly in FIG. 4 (the red LEDs 4 are shaded in the figure), the blue LEDs 3 and the red LEDs 4 are alternately mounted in a matrix on the mounting pad 22, and a plurality of blue LEDs 3 and An element array of red LEDs 4 is formed. Specifically, in the left and right element rows in FIG. 4, the blue LEDs 3 and the red LEDs 4 are alternately arranged in the direction in which the element rows extend. Electrically, three of the plurality of element rows are connected in series to form six series circuits 30, and these series circuits 30 are connected in parallel to the pair of power supply terminals 23. Yes. Therefore, power is supplied to the six series circuits 30 through the power supply terminal 23.

  More specifically, when attention is paid to one series circuit 30, for example, in the drawing, the blue LEDs 3 and the red LEDs 4 are alternately arranged and turned on the end side of the mounting pad 22. It is arranged in an S shape. In terms of number, there are 18 blue LEDs 3 and 15 red LEDs 4. First, the bonding wire 29 connected to the right power supply terminal 23 is connected to the element electrode 27 on the positive side of the blue LED 3, and the element electrode 27 on the other negative side of the blue LED 3 is connected to the adjacent red LED 4 by the bonding wire 29. The element electrode 28 on the negative electrode side of the red LED 4 is connected to the element electrode 28 on the positive electrode side, and further connected to the element electrode 27 on the positive electrode side of the adjacent blue LED 3 by a bonding wire 29.

  Such connections are sequentially made, and the electrodes of the opposite polarity of the blue LED 3 and the red LED 4 adjacent to each other in the extending direction of the row, that is, the element electrodes 27 and 28 on the positive side of the adjacent blue LED 3 or the red LED 4 are connected to each other. The element electrodes 28 and 27 on the negative side of the adjacent red LED 4 or blue LED 3 are connected by a bonding wire 29. The element electrode 27 on the negative side of the blue LED 3 at the tail of the column is connected to the left feeding terminal 23 by a bonding wire 29.

  The total number of blue LEDs 3 and red LEDs 4 used in the light emitting device 1 is 108 blue LEDs 3 and 90 red LEDs 4. The number of red LEDs 4 is about 0.8 times that of blue LEDs 3. It has become. The number and arrangement of the blue LEDs 3 and the red LEDs 4 are not particularly limited.

  As shown in FIGS. 1 and 2, the frame member 5 is formed by, for example, applying a non-cured silicone resin having a predetermined viscosity on the substrate 2 in a frame shape using a dispenser, and then heat-curing it. Bonded on the substrate 2. The frame member 5 is applied in a rectangular shape and has a substantially rectangular inner peripheral surface similar to the mounting pad 22. The entire mounting pad 22 is disposed inside the frame member 5, that is, the mounting regions of the blue LEDs 3 and the red LEDs 4 are surrounded by the frame member 5.

  The sealing member 7 as the wavelength converting means 6 is made of a light-transmitting synthetic resin, for example, a transparent silicone resin, and is provided on the substrate 2 while being filled inside the frame member 5. The sealing member 7 covers and seals the mounting pad 22, the connecting portion of the bonding wire 29 of the power supply terminal 23, and the blue LEDs 3 and the red LEDs 4. The surface of the sealing member 7 is configured as a light emitting surface that emits light to the outside.

  The sealing member 7 contains an appropriate amount of phosphor. The phosphor is excited by light emitted from the blue LED 3 and emits light having a color different from that of the light emitted from the blue LED 3. In order to be able to convert the blue light emitted by the blue LED 3 into white light, the phosphor emits light having a peak wavelength at a wavelength of 500 nm to 600 nm of yellow to green, which is complementary to the blue light. A yellow phosphor is used. The sealing member 7 is provided by being heat-cured after being injected into the frame member 5 in a predetermined amount in an uncured state. Therefore, the sealing area of the sealing member 7 is defined by the frame member 5. As the wavelength conversion means 6, a fluorescent filter may be used.

  When power is supplied to the light emitting device 1 having the above-described configuration through the power supply terminal 23, each blue LED 3 and red LED 4 emits light. The blue light emitted from the blue LED 3 excites the yellow phosphor contained in the sealing member 7, is converted from yellow phosphor to yellow to green fluorescence, passes through the sealing member 7, and is externally transmitted. To be emitted. Further, of the blue light emitted from the blue LED 3, the light that has not excited the yellow phosphor passes through the sealing member 7 as it is and is emitted to the outside. Further, the red light emitted from the red LED 4 passes through the sealing member 7 and is emitted to the outside without exciting the yellow phosphor.

  Further, during the light emission of each blue LED 3 and red LED 4, the mounting pad 22 functions as a heat spreader that diffuses the heat generated by the blue LED 3 and red LED 4. Further, the light emitted from the blue LED 3 and the red LED 4 toward the substrate 2 is reflected mainly by the surface layer of the mounting pad 22 in the light utilization direction.

  Therefore, the blue light from the blue LED 3, the yellow to green light from the yellow phosphor, and the red light from the red LED 4 are mixed from the light emitting device 1, and the color rendering property with a correlated color temperature of 2400K to 3600K is good. Light bulb color light is emitted.

  In this case, since red light is directly emitted from the red LED 4, the reddish component can be mixed efficiently and the color rendering properties are improved. However, as described above, the red LED 4 has a characteristic that a change in characteristics due to temperature is large, and a light emission color greatly changes due to a change in temperature. Therefore, the red LED 4 needs to be used in a limited manner in order to increase the luminous intensity, that is, for example, increase the number to improve the color rendering while reducing the influence of the characteristic change due to temperature.

  In the present embodiment, the red LED 4 is based on a balance between the improvement of color rendering properties and the reduction of the influence of characteristic changes due to temperature, and the light emitting device 1 adopts the COB method and emits light. Therefore, the numerical value is determined by paying attention to the luminous intensity ratio between the blue LED 3 and the red LED 4.

  The inventor conducted experiments and observations on the color rendering properties and the change in emission color depending on the temperature of the red LED 4.

  The measurement condition in the experiment is that an integrating sphere is used, and the luminous intensity and color temperature of the blue LED 3 and the red LED 4 of the light emitting device 1 before sealing by the sealing member 7 are measured by this integrating sphere. A plurality of measured values were obtained for the luminous intensity and the color temperature of the blue LED 3 and the red LED 4 while changing the input current to the. The temperatures of the blue LED 3 and the red LED 4 are within the normal operating temperature range when the light emitting device 1 is attached to the lighting device 41, that is, the junction temperature of each element of the blue LED 3 and the red LED 4 is within a range of 120 ° C. or less. And The lower limit of the junction temperature of each element of the blue LED 3 and the red LED 4 is the ambient temperature of the light emitting device 1.

  A part of the measurement results is shown in the table of FIG. The results of measuring the luminous intensity of the blue LED 3 and the luminous intensity of the red LED 4 at the color temperatures 2874K and 3283K and determining the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3 are shown. FIG. 6 shows the result of measuring the color temperatures of 2500K, 3000K, and 3500K in the same manner and determining the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3.

  FIG. 7 shows a graph created based on the measurement results shown in FIGS. The horizontal axis of the graph of FIG. 7 shows the relative color temperature, the vertical axis shows the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3, and among the three lines in the graph of FIG. This is a line connecting a plurality of actual measurement values shown in the table. Furthermore, the upper and lower two lines with respect to the central line in the graph of FIG. 7 fall within the wavelength range such as whether the light converted by the yellow phosphor contained in the sealing member 7 is a short wavelength or a long wavelength. The range of tolerances derived accordingly.

  FIG. 8 shows calculated values obtained by calculating the lower limit value and the upper limit value of the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3 when the correlated color temperature is 2400K and 3600K based on the measurement result.

  As a result of such measurement, within the range of the normal use temperature in the state in which the light emitting device 1 is attached to the lighting device 41, that is, within the range where the junction temperature of each element of the blue LED 3 and the red LED 4 in the lit state is 120 ° C. or lower. In order to obtain light bulb color light having a correlated color temperature of 2400K to 3600K and good color rendering, the luminous intensity of the red LED 4 is 1.7 times or less and 0.2 times or more, that is, 0. The opinion that it is desirable to set it to be 2 times or more and 1.7 times or less was obtained.

  Further, according to observation, it was confirmed that when the luminous intensity of the red LED 4 is less than 0.2 times that of the blue LED 3, the redness component is reduced and the color rendering is deteriorated. Moreover, if it exceeds 1.7 times and is less than 2.5 times, the reddish component increases, but it is within the allowable range as the color of the bulb, but if it exceeds 2.5 times, the reddish component increases too much. As a result, it was confirmed that the degree of the influence of the change in the emission color due to the temperature of the red LED 4 becomes significant.

  And, the red LED 4 of the present embodiment has a large rate of output decrease as the temperature rises compared to the blue LED 3, and when the temperature of the blue LED 3 and the red LED 4 rises, the luminous intensity of the red LED 4 decreases, Since the red component is reduced, the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3 tends to be small. On the other hand, when the temperature of the blue LED 3 and the red LED 4 decreases, the luminous intensity of the red LED 4 increases and the redness component increases. Therefore, the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3 increases. Tend.

  Therefore, based on the results of experiments and observations, when the light emitting device 1 using the red LED 4 and the blue LED 3 having such temperature characteristics is used in a state of being attached to the lighting device 41 within the range of the normal use temperature, that is, lighting When the junction temperature of each element of the blue LED 3 and the red LED 4 in the state is 120 ° C. or lower, and the correlated color temperature is in the range of 2400K to 3600K, the luminous intensity of the red LED 4 is 0.2 times or more with respect to the luminous intensity of the blue LED 3 The opinion was obtained that it is desirable to set it to be 2.5 times or less, more preferably 0.2 to 1.7 times. In short, if the ratio of the luminous intensity of the red LED 4 to the luminous intensity of the blue LED 3 is in the range of 0.2 to 2.5 times, more preferably in the range of 0.2 to 1.7 times, the temperature change The change in color temperature due to is acceptable.

  In the present embodiment, when the blue LED 3 and the red LED 4 are turned on, as an example, when the junction of each element of the blue LED 3 and the red LED 4 is about 90 ° C., the luminous intensity of the red LED 4 is 1.1 times that of the blue LED 3. And, it is designed in consideration of the characteristics and number of blue LEDs 3 and red LEDs 4 so that the correlated color temperature is 2900K. As a result, it is possible to emit light of a light bulb color having a correlated color temperature of 2400K to 3600K that has good color rendering properties and is less affected by changes in characteristics due to the temperature of the red LED 4.

  The quantum efficiency of the phosphor is preferably used in the range of 50% to 95%, and the luminous intensity of the red LED 4 is 0.2 times or more of the phosphor with the quantum efficiency in this range and the blue LED 3. It is preferable to realize a color temperature of 2400K to 3600K by combining with each element that is 5 times or less.

  In this embodiment, for example, when changing from the all-light state to the dimming state, as can be understood from the above description, the current value in the dimming state is lower than the current value in the all-light state. Therefore, the junction temperature of each element is lower in the dimming state than in the all-light state. Then, since the red component increases in the dimming state compared to the all-light state, the color temperature increases. The degree of change of the redness component in this dimming state shows a tendency similar to that of an incandescent bulb, and is therefore a very suitable state when used as an alternative to an incandescent bulb.

  As described above, according to the present embodiment, the junction temperature of each element of the blue LED 3 and the red LED 4 in the lit state is 120 ° C. within the range of the normal use temperature when the light emitting device 1 is attached to the lighting device 41. Within the following range, the color rendering property of the red LED 4 is 0.2 to 2.5 times, more preferably 0.2 to 1.7 times the light intensity of the blue LED 3. Thus, it is possible to provide the light emitting device 1 that can improve the light emission efficiency and reduce the influence of the change in the light emission color due to the temperature of the red LED 4.

  Further, since the blue LED 3 and the red LED 4 are alternately arranged, the color mixture of the light emitted from the blue LED 3 and the light emitted from the red LED 4 becomes good, and an intended light color can be obtained. .

  Furthermore, since the blue LED 3 and the red LED 4 are integrally sealed by the sealing member 7, the temperature of the blue LED 3 and the temperature of the red LED 4 can be made uniform, and the variation between the characteristics of the blue LED 3 and the characteristics of the red LED 4 can be achieved. , The color mixture of the light emitted from the blue LED 3 and the light emitted from the red LED 4 becomes good, and the desired light color can be obtained. Moreover, since blue LED3 and red LED4 can be integrally sealed with the sealing member 7, manufacturability is also good.

  Furthermore, since the blue LED 3 and the red LED 4 have a series circuit 30 connected in series, the blue LED 3 and the red LED 4 can be controlled by a single control system without lighting control using separate circuits. Lighting control can be performed, and the control system can be simplified. For example, a predetermined light color can be realized by selecting the number of blue LEDs 3 and red LEDs 4 in the series circuit 30 and mixing the colors.

  Next, the example which applied the light-emitting device 1 to the illuminating device 41 is demonstrated with reference to FIG.9 and FIG.10.

  In FIG. 9, a light bulb-shaped LED lamp 42 is shown as the illumination device 41. The LED lamp 42 includes a light emitting device 1, a device main body 42a that is thermally coupled to the light emitting device 1, a lighting circuit 42b that controls lighting of the light emitting device 1, a cover member 42c that houses the lighting circuit 42b, and a cover member 42c. 42 d and a globe 42 e that covers the light emitting device 1 and is attached to the apparatus main body 42 a.

  The device main body 42a is made of, for example, a metal material such as aluminum having good thermal conductivity, and has a substantially cylindrical shape whose diameter is gradually expanded from one end side to the other end side, and a plurality of radiating fins are provided on the outer peripheral surface. It is integrally formed.

  The lighting circuit 42b is configured by mounting circuit components on a rectangular flat lighting circuit board. Circuit components such as a transistor, a resistance element, a constant voltage diode, a full-wave rectifier, and a capacitor are mounted on both sides of the lighting circuit board. Further, the lighting circuit board is vertically arranged vertically and is housed in a cover member 42c formed of an insulating material such as PBT resin. The light emitting device 1 and the lighting circuit 42b are electrically connected by a lead wire that passes through a wiring hole (not shown) provided in the device main body 42a.

  According to the LED lamp 42 configured in this way, by supplying power to the light-emitting device 1 through the lighting circuit 42b, it is possible to efficiently transmit the desired light color through the globe 42e.

  FIG. 10 shows a downlight 43 that is used as a lighting device 41 embedded in a ceiling. The downlight 43 includes a light emitting device 1, a device main body 43 a in which the light emitting device 1 is accommodated, a light distribution member 43 b attached to the device main body 43 a, and a translucent light disposed in front of the light emitting device 1. A cover 43c and a power supply unit (not shown) for supplying power to the light emitting device 1 are provided. An attachment leaf spring 43d is mounted on the outer peripheral side of the apparatus main body 43a.

  The apparatus main body 43a is formed of a material having good thermal conductivity, for example, an aluminum alloy die casting. In addition, a plurality of heat radiation fins extending in the vertical direction are formed on the outer surface of the apparatus main body 43a.

  According to the downlight 43 configured in this way, by supplying power to the light emitting device 1 through the power supply unit, it is possible to obtain the desired light color emission that is transmitted through the cover 43c and controlled by the light distribution member 43b. it can.

  Next, a second embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the present embodiment, in the individual arrangement of the blue LEDs 3, the arrangement of the pair of element electrodes 27 of the blue LEDs 3 is arranged in a direction orthogonal to the direction in which the element rows in the left-right direction in the drawing extend. This makes it possible to reduce the dimension in the direction in which the element row extends.

  The blue LED 3 and the red LED 4 are alternately arranged on the mounting pad 22, and six series circuits are connected in parallel to each other.

  And in the range of the normal use temperature in the attachment state of the light-emitting device 1 to the illuminating device 41, that is, in the range where the junction temperature of each element of the blue LED 3 and the red LED 4 in the lighting state is 120 ° C. or less, the blue LED 3 The luminous intensity of the red LED 4 is set in the range of 0.2 to 2.5 times, and more preferably in the range of 0.2 to 1.7 times the luminous intensity.

  Therefore, according to 2nd Embodiment, there can exist an effect similar to 1st Embodiment mentioned above.

  Next, a third embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the present embodiment, the red LEDs 4 are arranged close to the power supply terminals 23 on both sides. That is, the red LED 4 is mounted on both sides of the mounting pad 22.

  The blue LED 3 and the red LED 4 are arranged on the mounting pad 22 and five series circuits 30 are connected in parallel to each other. When one series circuit 30 is taken, first, in the drawing, the bonding wire 29 connected to the right power supply terminal 23 is connected to the element electrode 28 on the positive side of the red LED 4, and further, the negative side of the red LED 4 is connected. The element electrode 28 of the red LED 4 is connected to the element electrode 28 on the positive side of the adjacent red LED 4 by the bonding wire 29, and then the element electrode 28 on the negative side of the red LED 4 is connected to the element on the positive side of the blue LED 3 by the bonding wire 29. It is connected to the electrode 27. Thereafter, the element electrode 27 of the blue LED 3 is sequentially connected by the bonding wire 29, connected to the two left red LEDs 4, and connected to the left power supply terminal 23.

  And like said each embodiment, in the range of the normal use temperature in the attachment state of the light-emitting device 1 to the illuminating device 41, that is, the junction temperature of each element of the blue LED3 and red LED4 of a lighting state is 120 degrees C or less. In this range, the luminous intensity of the red LED 4 is set in the range of 0.2 to 2.5 times, more preferably in the range of 0.2 to 1.7 times the luminous intensity of the blue LED 3. Has been.

  Therefore, according to the third embodiment, in addition to the operational effects of the first embodiment, it is possible to further reduce the influence of the characteristic change due to the temperature change of the red LED 4. That is, when a plurality of blue LEDs 3 and a plurality of red LEDs 4 are mounted on the substrate 2, the temperature of the central portion of the substrate 2 tends to rise, and the temperature change tends to increase. Therefore, the degree to which the red LED 4 is subjected to a temperature change can be reduced by not arranging the red LED 4 at the end portion side of the substrate 2, that is, at the center portion.

  Next, a fourth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the present embodiment, the red LED 4 connected in parallel is arranged in series with the blue LED 3 alternately to constitute a series circuit 30. And between each of these red LEDs 4 and blue LEDs 3, a rectangular connection conductor 32 is bonded with an insulating adhesive. Nine series circuits 30 are provided, and these are connected in parallel to the power supply side.

  More specifically, when one series circuit 30 is taken, in the drawing, the bonding wire 29 connected to the right power supply terminal 23 is connected to the element electrode 27 on the positive side of the blue LED 3, and the negative side of the blue LED 3. The element electrode 27 is connected to the connection conductor 32. Further, two bonding wires 29 are connected to the connection conductor 32, and these bonding wires 29 are connected to the element electrodes 28 on the positive side of the two adjacent red LEDs 4, respectively. Next, each bonding wire 29 connected to the device electrode 28 on the negative side of the two red LEDs 4 is connected to the connection conductor 32, and the device electrode 27 on the positive side of the blue LED 3 adjacent to this connection conductor 32 is bonded. Connected by wire 29. Thus, the blue LED 3 and the red LED 4 are sequentially connected by the bonding wire 29.

  And like said each embodiment, in the range of the normal use temperature in the attachment state of the light-emitting device 1 to the illuminating device 41, that is, the junction temperature of each element of the blue LED3 and red LED4 of a lighting state is 120 degrees C or less. In this range, the luminous intensity of the red LED 4 is set in the range of 0.2 to 2.5 times, more preferably in the range of 0.2 to 1.7 times the luminous intensity of the blue LED 3. Has been.

  Therefore, according to the fourth embodiment, in addition to the operational effects of the first embodiment, the current flowing through the red LED 4 can be reduced by connecting the red LEDs 4 in parallel. Therefore, it is possible to suppress a decrease in efficiency of the red LED 4 that greatly decreases in efficiency due to an increase in current.

  Next, a fifth embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the present embodiment, on the premise of the first embodiment, a yellow phosphor (first fluorescence) that emits light having a peak wavelength at a wavelength of 500 nm to 600 nm contained in the sealing member 7 in the first embodiment. In addition to the phosphor, a phosphor (second phosphor) that converts to a longer wavelength side than this is contained.

  Specifically, the blue LED 3 and the red LED 4 are mounted on the substrate 2, and the top is covered with a sealing member 7 containing two kinds of phosphors, a first phosphor and a second phosphor. is there. That is, the blue LED 3 and the red LED 4 are excited by the blue light emitted from the blue LED 3 to emit yellow or green fluorescence, and similarly, the blue LED 3 and the red LED 4 are excited by the blue light emitted from the blue LED 3 to be red. It seals with the sealing member 7 which mixed red fluorescent substance which emits this fluorescence with a desired mixing ratio.

  With such a configuration, a spectrum as shown in FIG. 14 is obtained. In FIG. 14, the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the relative intensity. As can be seen from this figure, light on the long wavelength side is added by the second phosphor, and it becomes possible to compensate for the shortage of the red component.

  Therefore, according to the fifth embodiment, the light emission efficiency can be improved by the blue LED 3 and the red LED 4, while the red LED 4 is used to supplement the reddish component to reduce the luminous intensity of the red LED 4. It is possible to reduce the influence of the characteristic change due to the temperature change.

  Next, a sixth embodiment will be described with reference to FIGS. 15 and 16. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the present embodiment, a second red LED 4b is mounted in addition to the blue LED 3 and the red LED 4 (first red LED 4a) mounted on the substrate 2 in the third embodiment. The second red LED 4b has a longer emission wavelength of 625 nm to 645 nm than the first red LED 4a as shown in the emission spectrum of FIG. With such a configuration, it is possible to supplement the reddish component and further improve the color rendering properties.

  As shown in FIG. 16, for example, the second red LEDs 4b may be arranged in the central three element rows. Specifically, it is disposed adjacent to the first red LEDs 4a on both sides in the element row. In this case, the second red LED 4b is preferably set lower than the luminous intensity of the first red LED 4a because the luminous efficiency is low. For example, 14 first red LEDs 4a are mounted, whereas 6 second red LEDs 4b are mounted.

  The lighting device 41 can be applied to a light source, a lighting fixture used indoors or outdoors, a display device, and the like.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Board | substrate 3 Blue light emission LED element 4 Red light emission LED element 6 Wavelength conversion means
30 series circuit
41 Lighting equipment
42a, 43a Main unit

Claims (4)

A light emitting device attached to a lighting device and having a correlated color temperature of emitted light of 2400K to 3600K,
A substrate;
A blue light emitting LED element mounted on the substrate;
A red light-emitting LED element mounted on the substrate and having a light intensity of 0.2 to 2.5 times the light intensity of the blue light-emitting LED element at a normal use temperature when attached to the lighting device;
Wavelength conversion means that is excited by light emitted from the blue light emitting LED element and converts the light into light having a peak at a wavelength of 500 nm to 600 nm;
A light-emitting device comprising:   The light emitting device according to claim 1, further comprising a series circuit in which the blue light emitting LED element and the red light emitting LED element are connected in series.   3. The light emitting device according to claim 1, wherein a plurality of the blue light emitting LED elements and the red light emitting LED elements are mounted on the substrate, and these are alternately arranged. The device body;
The light emitting device according to any one of claims 1 to 3, wherein the light emitting device is disposed in the device body;
An illumination device comprising:

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