JP2012064362A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system capable of discharging heat from a light emitting element efficiently without deteriorating total luminous flux and attaining downsizing.SOLUTION: An LED bulb 100 has a substrate 6 mounting an LED element 7 (the LED element 7 and the substrate 6 are collectively called an LED package 16) mounted on an LED installation table 2. Further, the LED package 16 has a sealing material for sealing the LED element 7. A globe 1 has a dome shape and covers the substrate 6 and the LED element 7 or the like. A heat conduction member 11 having a band in a lattice shape and in contact with the inner face of the globe 1 with the contact face of the lattice shape is arranged on the inner face of the globe 1.

Description

  The present invention relates to a lighting device including a substrate on which a light-emitting element is mounted, and a light-transmitting element and a transmission portion that covers the substrate and transmits light from the light-emitting element.

  In recent years, light-emitting elements such as light-emitting diodes (hereinafter also referred to as “LEDs”) or organic EL have been improved in light emission efficiency, downsizing, low power consumption, long life, and the like. It is used as a light source. As an example, LED bulbs using LEDs as light sources have been commercialized as alternatives to conventional incandescent bulbs and bulb-type fluorescent lamps.

  An LED bulb is an LED package (LED module) in which an LED element (LED chip) is mounted on a substrate, a power supply circuit for supplying power to the LED element, a glove that houses the LED package, and heat generated by the LED element. It consists of parts such as a heat sink and a base for electrical and mechanical connection to the lamp.

  In an LED bulb, in order to ensure the same total luminous flux as that of an incandescent bulb, it is necessary to increase the power supplied to the LED element, and the temperature of the LED element in the lighting state increases. When the temperature of the LED element rises, the light emission efficiency of the LED element decreases, and more power must be supplied to compensate for the decrease in light emission efficiency, resulting in a vicious circle in which the temperature of the LED element further increases. .

  In order to avoid such a vicious circle, there is a method of increasing the heat sink and dissipating the heat generated by the LED element to the outside. However, when the heat sink is made larger, the size of the LED bulb itself becomes larger than that of the conventional incandescent bulb or the bulb-type fluorescent lamp, and there is a problem that it cannot be attached to an existing lamp and the installation rate is lowered and cannot be used as a substitute.

  Therefore, a heat transfer portion having a heat conductivity higher than the heat conductivity of the globe is formed on the inner surface of the globe (valve) and has a heat conductivity equal to or higher than the heat conductivity of the light transmissive layer. A lamp capable of efficiently releasing heat from the LED element by connecting a part of the light-transmitting layer to a heat sink via the LED is disclosed (see Patent Document 1).

JP 2010-16223 A

  However, in the lamp of Patent Document 1, in order to form a translucent layer on the inner surface of the globe (bulb) and conduct heat from the LED element to the probe, the thermal conductivity of the translucent layer is low. It is necessary to use a material that is at least as high as metal. However, a material having a thermal conductivity equal to or higher than that of metal generally has low light transmissivity. For this reason, the lamp of Patent Document 1 has a problem that the light transmittance is reduced and the total luminous flux is reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an illumination device that can efficiently release heat from a light-emitting element without reducing the total luminous flux and can be downsized. And

  An illuminating device according to the present invention is an illuminating device including a substrate on which a light-emitting element is mounted, and a light-transmitting portion that covers the light-emitting element and the substrate and transmits light from the light-emitting element. One of the longitudinal end portions is in contact with the inner surface of the light transmitting part, and includes a heat conductive member that conducts heat of the light emitting element, and the heat conductivity of the heat conductive member is greater than the heat conductivity of the light transmitting part. It is large.

  In the present invention, a heat conducting member that conducts heat of the light emitting element is provided by contacting one of the long side end portions of the strip arranged in a lattice shape with the inner surface of the light transmitting portion. Since the heat conductive layer is not provided so as to cover the entire inner surface of the translucent portion as in the prior art and the heat conductive member has a lattice shape, the light from the light emitting element can be obtained even when the light transmittance of the heat conductive member is small. It is possible to avoid a decrease in the total luminous flux without blocking. In addition, since the heat conducting member having a thermal conductivity larger than that of the light transmitting part is in contact with the light transmitting part, when the heat from the light emitting element is transmitted to the heat conducting member, the heat is also transmitted to the light transmitting part. The temperature of the translucent part rises and the radiation effect by radiation and convection from the translucent part can be enhanced. Accordingly, heat from the light emitting element is efficiently released without interfering with light emitted from the light emitting element, so that the temperature rise of the light emitting element can be suppressed and the light emission efficiency of the light emitting element is improved. In addition, since it is not necessary to use a large heat sink, the size of the lighting device can be reduced, and the mounting rate of the lighting device can be improved because it can be attached to an existing lamp.

  The lighting device according to the present invention includes a heat sink on which the substrate is placed, and the heat sink and the heat conducting member are thermally connected.

  In the present invention, the heat radiating plate on which the substrate is placed is provided, and the heat radiating plate and the heat conducting member are thermally connected. The heat generated in the light emitting element is transmitted to the substrate, and the heat transmitted to the substrate is transmitted to the heat sink. Since the heat radiating plate and the heat conductive member are thermally connected, the heat transmitted to the heat radiating plate is transmitted to the heat conductive member, and the temperature of the light transmitting portion further increases. Thereby, the heat from the light emitting element can be released more efficiently.

  The illuminating device according to the present invention is characterized in that the light-transmitting portion has a dome shape, and the heat conducting member is in contact with the inner surface of the light-transmitting portion excluding the inner surface.

  In the present invention, the light-transmitting portion has a dome shape, and the heat conducting member is in contact with the inner surface of the light-transmitting portion excluding the top inner surface. Since there is no heat conducting member on the inner surface of the top of the translucent part, that is, the position (surface) that opposes the light emitting element of the translucent part, for example, with a lighting device attached to the lamp, a grid-like heat conduction from the outside The member becomes difficult to see. As a result, the light-transmitting part is not bright and dark, and a sense of incongruity does not occur. Moreover, in the top part of a translucent part, light is not blocked | interrupted with a heat conductive member, but the fall of a total light beam can be suppressed.

  The lighting device according to the present invention is characterized in that the thickness of the band is gradually reduced from one of the longitudinal side end portions to the other direction.

  In the present invention, the thickness of the band is gradually reduced from one of the long side end portions, that is, from the contact surface to the other direction of the long side end portion. That is, the tangential direction from one end of the longitudinal end of the surface of the band to the other and the traveling direction of the light emitted from the light emitting element to the light transmitting portion substantially coincide with each other or intersect at a small intersection angle. . As a result, when the light emitted from the light emitting element is reflected by the surface of the band, it is reflected in the direction of the light transmitting part, so that the light from the light emitting element can be emitted from the light transmitting part to the outside. A decrease in luminous flux can be suppressed. Moreover, since the light reflected by the surface of the strip | belt body arrange | positioned at the grid | lattice form can be guide | induced to the exterior of a translucent part, a light distribution characteristic can be improved.

  The lighting device according to the present invention is characterized in that the cross-sectional shape of the strip in the short direction is a triangular shape.

  In the present invention, the cross-sectional shape of the band in the short direction is a triangular shape. That is, since the triangular apex faces the direction of the light emitting element, it is possible to prevent light emitted from the light emitting element from being reflected by the band plate and returning to the direction of the light emitting element or the inside of the light transmitting part. When the light emitted from the light-emitting element is reflected by the surface of the band, the light is reflected in the direction of the light-transmitting part, and all the light from the light-emitting element can be emitted from the light-transmitting part to the outside. Will not decrease.

  The illuminating device according to the present invention is characterized in that the cross-sectional shape of the strip in the short direction is a trapezoidal shape.

  In the present invention, the cross-sectional shape in the short direction of the band is trapezoidal. That is, the perpendicular direction of the upper base surface (upper bottom surface) of the trapezoidal shape faces the direction of the light emitting element. Thereby, when the light emitted by the light emitting element is reflected by the upper bottom surface of the band, the reflected light returns to the direction of the light emitting element or the inside of the light transmitting part. However, since the light reflected on the surface other than the upper bottom surface is reflected in the direction of the light transmitting part, the light from the light emitting element can be emitted from the light transmitting part to the outside, and the decrease in the total luminous flux is suppressed. Can do.

  The lighting device according to the present invention is characterized in that the width of the contact surface of the belt body with the light transmitting portion is 0.5 mm or more and 1.0 mm or less.

  In this invention, the width | variety of the contact surface with the translucent part of a strip | belt body is 0.5 mm or more and 1.0 mm or less. By making the width of the contact surface 0.5 mm or more and 1.0 mm or less, the contact area between the heat conducting member and the light transmitting portion can be increased as necessary and heat from the heat conducting member to the light transmitting portion. Since the temperature of the translucent part rises due to conduction, the heat dissipation effect can be improved. In addition, the contact area between the heat conducting member and the light transmitting portion can be made sufficiently small, and the light from the light emitting element can be prevented from being blocked by the heat conducting member, thereby preventing the reduction of the total luminous flux. .

  The lighting device according to the present invention is characterized in that the heat conduction member has a heat conductivity of 100 W / (m · K) or more.

  In the present invention, the heat conductivity of the heat conducting member is 100 W / (m · K) or more. Thereby, since the temperature of a heat conductive member rises, the temperature of a translucent part can also be raised and the heat dissipation effect improves.

  The illumination device according to the present invention is characterized in that a reflectance of the heat conducting member is 0.9 or more.

  In the present invention, the reflectance of the heat conducting member is 0.9 or more. Thereby, the light irradiated to the heat conductive member can be reflected efficiently, and the reduction of the total luminous flux can be prevented.

  According to the present invention, heat from the light emitting element is efficiently released without interfering with light emitted from the light emitting element, so that the temperature rise of the light emitting element can be suppressed, and the light emission efficiency of the light emitting element is improved. In addition, since it is not necessary to use a large heat sink, the size of the lighting device can be reduced, and the mounting rate of the lighting device can be improved because it can be attached to an existing lamp.

1 is an external view illustrating an example of an LED bulb according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view showing an example of the LED bulb according to the first embodiment. 3 is a perspective view showing an example of a heat conducting member according to Embodiment 1. FIG. 3 is a plan view illustrating an example of a heat conductive member according to Embodiment 1. FIG. 3 is a side view showing an example of a heat conducting member according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view illustrating an example of an attached state of the heat conducting member according to the first embodiment. It is explanatory drawing which shows the example in case the cross-sectional shape of the strip | belt body of a heat conductive member is a triangle. It is explanatory drawing which shows the example in case the cross-sectional shape of the strip | belt body of a heat conductive member is a rectangle. It is explanatory drawing which shows the example in case the cross-sectional shape of the strip | belt body of a heat conductive member is circular. It is explanatory drawing which shows the example in case the cross-sectional shape of the strip | belt body of a heat conductive member is trapezoid. It is explanatory drawing which shows the example in case the cross-sectional shape of the strip | belt body of a heat conductive member is a rhombus. It is a perspective view which shows the other example of a heat conductive member. It is a perspective view which shows the other example of a heat conductive member. It is a perspective view which shows the other example of a heat conductive member. 6 is a cross-sectional view showing an example of an LED bulb according to Embodiment 2. FIG. FIG. 6 is a perspective view illustrating an example of a heat conductive member according to a second embodiment. FIG. 6 is a plan view showing an example of a heat conductive member according to a second embodiment. FIG. 6 is a side view showing an example of a heat conducting member of a second embodiment. It is a perspective view which shows the other example of a heat conductive member. It is a perspective view which shows the other example of a heat conductive member. It is a perspective view which shows the other example of a heat conductive member.

(Embodiment 1)
Hereinafter, the present invention will be described based on an LED bulb as an example based on the drawings showing the embodiments thereof. In addition, the illuminating device of this Embodiment is not limited to an LED light bulb.

  FIG. 1 is an external view showing an example of the LED bulb 100 according to the first embodiment, FIG. 2 is a cross-sectional view showing an example of the LED bulb 100 according to the first embodiment, and FIG. 3 is a heat conduction diagram of the first embodiment. 4 is a perspective view showing an example of the member 11, FIG. 4 is a plan view showing an example of the heat conducting member 11 of the first embodiment, and FIG. 5 is a side view showing an example of the heat conducting member 11 of the first embodiment. It is.

  As shown in FIG. 1, the LED bulb 100 is externally provided with a globe 1 as a translucent part, an LED mounting base 2 as a heat sink on which an LED package is placed, a heat sink 3, an insulating ring 4, a base 5, and the like. .

  More specifically, as shown in FIG. 2, the LED bulb 100 includes a substrate 6 on which an LED element 7 (LED chip) as a light emitting element is mounted (the LED element 7 and the substrate 6 are collectively referred to as an LED package 16). It is mounted on the LED mounting base 2. The LED package 16 has a sealing material (not shown) for sealing the LED element 7.

  The globe 1 has a dome shape and covers the substrate 6, the LED element 7, and the like. On the inner surface of the globe 1, a belt body is arranged in a lattice shape, and a heat conductive member 11 is provided that contacts the inner surface of the globe 1 with a lattice-shaped contact surface. The heat conducting member 11 contacts (contacts) the globe 1 on the inner surface 102 excluding the top inner surface 101 of the globe 1.

  A power supply board 12 for supplying power to the LED element 7 is provided inside the heat sink 3, and power from the power supply board 12 is supplied to the LED package 16 through the lead wires 10. Further, the base 5 and the power supply substrate 12 are connected by the conductive wire 9, and an AC voltage from a commercial power supply is supplied to the power supply substrate 12 through the base 5.

  The insulating ring 4 electrically insulates the heat sink 3 from the base 5. The insulating ring 4 is filled with a filler 8.

The LED element 7 has a semiconductor light emitting layer made of gallium nitride (GaN) stacked on top of a sapphire (Al ₂ O ₃ ) substrate 6 which is an insulating substrate, and an electrode layer (ITO layer) formed on the upper surface. Is. The LED element 7 is wire-bonded and mounted on the substrate 6 with a wire. The substrate 6 is wired, and the LED element 7 is electrically connected to the wiring on the substrate 6.

  The sealing material that seals the LED elements 7 is made of resin, covers the plurality of LED elements 7, and suppresses deterioration of the LED elements 7. Moreover, the sealing material contains the fluorescent paint and can convert the color of the light emitted from the LED element 7 into a desired color.

  In addition, a light emitting element is not limited to the LED element 7, For example, an EL element can also be used. Moreover, although the above-described LED package 16 is used as a light source, the present invention is not limited to this, and various light sources that are conventionally used as a light source (for example, a flip-chip mounted LED package) can be used.

  The globe 1 is formed in a dome shape with a translucent polycarbonate (PC). The material of the globe 1 is not limited to polycarbonate, and a material such as glass or acrylic can be used as long as the material has translucency.

  The globe 1 is disposed on the LED mount 2 and is fixed by a known method such as an adhesive or a screw. A process of diffusing light is performed on the inner surface side or outer surface side of the globe 1, and the light emitted from the LED package 16 is diffused. Moreover, the radius of the opening part of the globe 1 is smaller than the dome-shaped radius. Note that the radius of the opening of the globe 1 may be approximately the same as the dome-shaped radius in order to facilitate attachment of the heat conducting member 11.

  The LED mounting base 2 is a base for mounting the LED package 16 (substrate 6). In order to transmit the heat generated from the LED package 16 to the heat sink 3 and the heat conducting member 11, the material of the LED mounting base 2 is aluminum (A6063). In addition, the material of the LED mounting base 2 is not restricted to this, For example, various materials, such as metals, such as iron, copper, aluminum, and its alloy, can be used if it is a material with high heat conductivity. .

  The heat sink 3 is provided with a plurality of radiating fins radially on the side surface from the center of the heat sink 3 to the outside, and radiates heat generated from the LED package 16. The heat sink 3 is fixed to the LED mounting base 2 by a known method such as an adhesive, a screw, and caulking. In order to efficiently transfer the heat transferred from the LED package 16 through the LED mount 2 to the entire heat sink 3, the material of the heat sink 3 is aluminum (A6063). The material of the heat sink 3 is not limited to this, and various materials such as metals such as iron, copper, and aluminum and alloys thereof can be used as long as the materials have high thermal conductivity.

  The surface of the heat sink 3 is anodized. Since the emissivity of the heat sink 3 is higher than that of normal aluminum, heat can be radiated effectively. The surface treatment of the heat sink 3 is not limited to this, and various means for improving the emissivity, such as applying a radiation paint, can be used.

  The insulating ring 4 is a member for insulating the heat sink 3 and the base 5 so as not to come into electrical contact. The material of the insulating ring 4 is, for example, polybutylene terephthalate (PBT). The material of the insulating ring 4 is not limited to this, and various materials such as polycarbonate (PC) can be used as long as the material is highly insulating. The insulating ring 4 is fixed to the heat sink 3 by a known method such as an adhesive or a screw.

  The power supply board 12 includes a plurality of electronic components (not shown) (for example, a rectifier circuit that rectifies AC power supplied from a commercial power source into DC power, a voltage adjustment circuit that adjusts the voltage value of the DC power rectified by the rectifier circuit, etc. ) Is a mounted board. The power supply board 12 is a circuit board for causing the LED package 16 (LED element 7) to emit light. The power supply board 12 is fixed to the insulating ring 4 by a known method such as a locking means or a fixing means.

  The base 5 is, for example, an Edison-type E26-type base, and has a metallic shell portion formed in a cylindrical shape with a thread. The base 5 has a metal eyelet part at the top of one end side of the shell part via an insulating part, and the other end side is attached to the insulating ring 4.

  The filler 8 is filled in the insulating ring 4 and the base 5, and covers the power supply substrate 12. The material of the filler 8 is a resin having a high insulating property and a high thermal conductivity, and has a role of conducting heat generated from the power supply substrate 12 to the insulating ring 4 and the base 5.

  The conducting wire 9 is a wiring for electrically connecting the power supply substrate 12 and the base 5. The conducting wire 9 is connected to the inner surface of the eyelet part of the power supply board 12 and the base 5, and the conducting wire (not shown) is connected to the inner side face of the shell part of the power supply board 12 and the base 5, It has a role of transmitting power supplied from the lamp to the power supply substrate 12 in contact with the electrode.

  The lead wire 10 is a wiring for electrically connecting the power supply substrate 12 and the LED package 16. DC power rectified and adjusted by the power supply substrate 12 is supplied to the LED package 16 via the lead wire 10.

  As shown in FIGS. 3 to 5, the heat conducting member 11 includes a mounting portion 111 for mounting by thermally connecting to the LED mounting base 2, and a plurality of strip-shaped belt bodies 112, 113, 114, 115. . The heat conducting member 11 has strips 112 to 115 arranged in a lattice pattern, and one of the longitudinal side ends of the strips 112 to 115 is in contact with the inner surface 102 of the globe 1.

  More specifically, the heat conducting member 11 is configured so that the strips 112 to 114 form three rows of lattices in the circumferential direction at equal intervals along the circumferential direction on the inner surface side of the globe 1. Further, the heat conducting member 11 is constituted by 24 belts 115 so that vertical lattices are radially arranged in 24 rows along the circumferential direction on the inner surface side of the globe 1.

  In addition, since the effect of transferring heat to the globe 1 increases as the number of lattice rows increases, that is, the interval between the lattices becomes narrower, the number of lattices of the heat conducting member 11 depends on how much the temperature of the LED bulb 100 is lowered. Can be determined.

  As shown in FIGS. 3 to 5, the heat conducting member 11 also has a dome shape like the globe 1. The heat conducting member 11 is provided with an opening 116 at the top of the dome without forming a lattice. When the heat conducting member 11 is attached to the inside of the globe 1, the heat conducting member 11 abuts on the inner surface 102 excluding the top inner surface 101 of the globe 1. That is, the heat conducting member 11 does not cover the part (upper part) of the globe 1 at a position facing the LED package 16. In general, when the LED bulb 100 is attached to a lamp, the central portion (dome-shaped top portion) of the globe 1 can be seen. Therefore, by preventing the central portion (dome-shaped top portion) of the globe 1 from being blocked by the heat conducting member 11, the lattice-like heat conducting member 11 can be made difficult to visually recognize from the outside.

  The heat conducting member 11 is attached to the inner surface side of the globe 1 with an adhesive and is thermally connected. The higher the thermal conductivity of the adhesive, the better. Further, the heat conducting member 11 is thermally connected to the LED mounting base 2 by a heat radiating resin or the like, whereby heat generated by the LED package 16 is transmitted to the heat conducting member 11 via the LED mounting base 2. The heat transmitted to the heat conducting member 11 is further transmitted to the globe 1 and is radiated from the globe 1. The method of attaching the heat conducting member 11 to the globe 1 is not limited to the adhesive, and various means such as insert molding on the globe 1 can be used.

  The material of the heat conductive member 11 is aluminum (A6063), and the heat conductivity of the heat conductive member 11 is 210 W / (m · K), which is excellent in heat transfer effect. Note that the material of the heat conducting member 11 is not limited to aluminum, and various materials such as metals such as iron, copper, and aluminum and alloys thereof may be used as long as the materials have high heat conductivity. it can. In order to make the heat conduction to the globe 1 effective, the heat conductivity of the heat conducting member 11 may be 100 W / (m · K) or more.

  FIG. 6 is a cross-sectional view showing an example of an attached state of the heat conducting member 11 of the first embodiment. Heat conduction is performed so that one of the longitudinal end portions of the belt bodies 112, 113, 114 (the belt body 115 is not shown) of the heat conducting member 11 is in contact with the inner surface 102 of the globe 1 at the contact surface 14. The member 11 is fixed to the globe 1. The following description is the same for the band 115.

  As shown in FIG. 6, the cross-sectional shape of the strips 112 to 114 in the short direction is from the contact surface 14 (one of the long side end portions) to the LED element 7 (the other direction of the long side end portion). It has a tapered shape with a gradually decreasing thickness. In the example of FIG. 6, the cross-sectional shapes of the strips 112 to 114 are triangular. That is, the triangular shape has two virtual straight lines (solid lines in FIG. 6) connecting the outermost surface of the light emitting surface (LED element 7) of the LED package 16 and the outermost surface of the contact surface 14 of the heat conducting member 11 respectively. The broken line) is the two sides, and the contact surface 14 with the globe 1 is the third side.

  The tangential direction of the surfaces of the belts 112 to 114 in the direction of the LED element 7 (the direction of the solid line and the broken line in FIG. 6) and the traveling direction of the light emitted from the LED element 7 toward the globe 1 are substantially the same, or Intersect with a small crossing angle. Thereby, the light emitted from the LED element 7 is incident on the surface of the belt bodies 112 to 114 at an incident angle close to 90 degrees, and the incident light is directed in the direction of the globe 1 along the surface of the belt bodies 112 to 114. Therefore, the light from the LED element 7 can be emitted from the globe 1 to the outside, and the decrease in the total luminous flux can be suppressed. Moreover, since the light reflected on the surface of the strips 112 to 114 arranged in a lattice shape can be guided to the outside of the globe 1, the light distribution characteristics can be improved. In the example of FIG. 6, the cross-sectional shape of the heat conducting member 11 has a triangular shape, but is not limited to a triangular shape.

  Next, the difference in the cross-sectional shape in the short direction of the band of the heat conducting member 11 will be described. FIG. 7 is an explanatory view showing an example in which the cross-sectional shape of the strip 113 of the heat conducting member 11 is a triangle. In addition, although FIG. 7 demonstrates the strip | belt body 113 of the heat conductive member 11, it is the same also about the other strip | belt bodies 112,114,115.

  As shown in FIG. 7, the cross-sectional shape of the belt body 113 is a triangular shape composed of three surfaces: the contact surface 14 on which the belt body 113 contacts the inside of the globe 1, and the two surfaces 113 a and 113 b of the belt body 113. Make. The belt body 113 is fixed to the globe 1 with an adhesive 13.

  As shown in FIG. 7, when the cross-sectional shape of the strip 113 is triangular, the light emitted from the outermost peripheral portion of the light emitting surface (LED element 7) of the LED package 16 is the surface 113a or the surface 113b of the strip 113. Is incident on the surface 113a or the surface 113b, passes through the globe 1 and is emitted outside the LED bulb 100. Since the same phenomenon occurs on all the light emitting surfaces of the LED package 16, an effect that the total luminous flux does not decrease can be obtained. Moreover, since it has the strip | belt body arrange | positioned at the grid | lattice form, the light reflected by the heat-conducting member 11 diffuses, and since it progresses also to the back side (the heat sink 3 side seeing from the globe 1) of the LED bulb 100, the LED bulb 100 light distribution characteristics are improved.

  Further, since the cross-sectional shape of the band 113 is a triangle, that is, since the apex of the triangle is directed toward the LED element 7, the light emitted from the LED element 7 is reflected by the band 113 and the LED element 7 It is possible to prevent the LED bulb 100 from being absorbed by returning to the direction or returning to the inside of the globe 1 opposite to the globe 1. Thereby, when the light emitted from the LED element 7 is reflected on the surface of the band 113, the light is reflected in the direction of the globe 1 and all the light from the LED element 7 is emitted from the globe 1 to the outside. And the total luminous flux does not decrease.

  FIG. 8 is an explanatory diagram showing an example in which the cross-sectional shape of the belt 103 of the heat conducting member 11 is rectangular. As shown in FIG. 8, when the cross section of the band 103 is rectangular, when the light emitted from the outermost periphery of the light emitting surface (LED element 7) of the LED package 16 is incident on the band 103, the band 103 When the light is incident on a surface other than the end surface 103 c of the body 103, the incident light is reflected by the band body 103 and radiated out of the LED bulb 100. However, when the light enters the end surface 103 c of the band 103, the incident light is reflected by the end surface 103 c and the reflected light returns to the inside of the LED bulb 100. As a result, of the light emitted from the LED element 7, the light incident on the region indicated by the symbol A in FIG. 8 is not emitted outside the LED bulb 100 but absorbed inside. Since the same phenomenon occurs in all the light emitting surfaces of the LED package 16, the total luminous flux is reduced. The case where the cross-sectional shape is a square is the same as the case of a rectangle.

  FIG. 9 is an explanatory view showing an example in which the cross-sectional shape of the band 203 of the heat conducting member 11 is circular. As shown in FIG. 9, when the band 203 has a circular cross-sectional shape, the light emitted from the outermost peripheral portion of the light emitting surface (LED element 7) of the LED package 16 is incident on the band 203. When incident on a surface other than the substantially half surface 203 c of the body 203, the incident light is reflected by the band body 203 and emitted outside the LED bulb 100. However, when the light enters the substantially half surface 203c of the band 203, the incident light is reflected by the half surface 203c, and the reflected light returns to the inside of the LED bulb 100. As a result, of the light emitted from the LED element 7, the light incident on the region indicated by the symbol A in FIG. 9 is absorbed without being emitted outside the LED bulb 100. Since the same phenomenon occurs in all the light emitting surfaces of the LED package 16, the total luminous flux is reduced.

  FIG. 10 is an explanatory view showing an example in which the cross-sectional shape of the band 123 of the heat conducting member 11 is a trapezoid. As shown in FIG. 10, when the cross-sectional shape of the strip 123 is trapezoidal, the light emitted from the outermost periphery of the light emitting surface (LED element 7) of the LED package 16 Only when the light enters the bottom surface 123c, the light is reflected and returned to the inside of the LED bulb 100, and the light incident on the surface 123a or the surface 123b other than the upper bottom surface 123c is emitted to the outside of the LED bulb 100. As a result, of the light emitted from the LED element 7, only the light incident on the region indicated by the symbol A in FIG. 10 is not radiated out of the LED bulb 100, and the body part of the light emitted from the LED element 7. Is reflected by the surfaces 123a and 123b and emitted outside the LED bulb 100. Since the same phenomenon occurs on all of the light emitting surfaces of the LED package 16, it is possible to suppress the decrease of the total luminous flux as compared with the case where the shape of the band is rectangular or circular.

  FIG. 11 is an explanatory view showing an example in which the cross-sectional shape of the band 133 of the heat conducting member 11 is a rhombus. As shown in FIG. 11, when the cross-sectional shape of the band 133 of the heat conducting member 11 is rhombus, in addition to the advantages or effects when the cross-sectional shape is a triangle, the light hitting the heat conducting member 11 is reduced, and heat is applied from the outside. There is also an effect that the conductive member 11 becomes difficult to visually recognize. In this case, since light passes through the adhesive 13, it is desirable to use a material having high translucency and high thermal conductivity. In the example of FIG. 11, the adhesive 13 can be a part of the band 133.

  As illustrated in FIGS. 7 to 11, various shapes can be used for the cross-sectional shape in the short direction of the band of the heat conducting member 11. However, in order to suppress the reduction of the total luminous flux, the cross-sectional shape is rectangular (square), circular, trapezoidal as long as the widths of the contact surfaces of the belt (including the adhesive 13) and the globe 1 are equal. More effects can be obtained in the order of triangles (diamonds). However, the cross-sectional shape of the band may be a rectangle, a square, a circle, or the like depending on the lattice spacing. 7 to 11, the widths of the contact surfaces of the strips are assumed to be the same.

  As described above, when the cross-sectional shape of the belt is triangular or trapezoidal, it is effective for suppressing the decrease in the total luminous flux. However, the cross-sectional shape is not limited to a triangle or a trapezoid. For example, a taper shape that gradually decreases in thickness from the contact surface 14 toward the LED element 7 may be formed. That is, the cross-sectional shape is set so that the tangential direction of the surface of the belt body in the direction of the LED element 7 and the traveling direction of the light emitted from the LED element 7 toward the globe 1 substantially coincide with each other or intersect at a small intersection angle. can do. Thereby, when the light emitted from the LED element 7 is reflected on the surface of the band, it is reflected in the direction of the globe 1, so that the light from the LED element 7 can be emitted from the globe 1 to the outside. A decrease in luminous flux can be suppressed. Moreover, since the light reflected by the surface of the strip | belt body distribute | arranged to the grid | lattice form can be guide | induced to the exterior of the globe 1, a light distribution characteristic can be improved. Further, the cross-sectional shape of the band may be a shape similar to the above-described shape (for example, a shape in which corner portions are chamfered or filleted).

  The width of the contact surface 14 between the belt (including the adhesive 13) and the globe 1 is 0.5 mm. Note that the width of the contact surface 14 can be changed by the thermal conductivity of the heat conducting member 11. However, when the width of the contact surface 14 is small, it becomes difficult to transfer heat to the globe 1, and when the width is large, an optical problem may occur in design. For this reason, the width of the contact surface 14 is desirably 0.5 mm or greater and 1.0 mm or less. That is, by setting the width of the contact surface 14 to 0.5 mm or more and 1.0 mm or less, the contact area between the heat conducting member 11 and the globe 1 can be increased sufficiently and sufficiently. Since the temperature of the globe 1 rises due to heat conduction to the heat dissipation effect, the heat dissipation effect can be improved. In addition, the contact area between the heat conducting member 11 and the globe 1 can be made sufficiently small, and the light from the LED element 7 is prevented from being blocked by the heat conducting member 11 to prevent the reduction of the total luminous flux. Can do.

  The surface of the heat conducting member 11 is mirror-finished, and the reflectance in the visible light region is 0.95. For this reason, most of the light incident on the surface of the heat conducting member 11 is reflected, passes through the globe 1, and is emitted outside the LED bulb 100. Note that the reflectance of the heat conducting member 11 does not have to be 0.95. For example, the light is effectively reflected by performing a surface treatment so that the reflectance is 0.9 to less than 0.95. And reduction of the total luminous flux can be prevented. That is, by setting the reflectance of the heat conducting member 11 to 0.9 or more, the light irradiated to the heat conducting member 11 can be reflected efficiently, and the reduction of the total luminous flux can be prevented.

  Next, the heat dissipation path will be described. Heat generation of the electronic components on the power supply board 12 is transmitted to the base 5 mainly through the power supply board 12 and the filler 8 or via the lead wire 9, and is transmitted from the base 5 to a lamp (not shown), and 100 bulbs of the LED bulb. Is radiated to the outside by radiation, convection and heat conduction. Further, part of the heat generated by the electronic components on the power supply board 12 is transmitted to the insulating ring 4 through the power supply board 12 and the filler 8 and is radiated to the outside of the LED bulb 100 by radiation and convection. Further, part of the heat generation is transmitted to the heat sink 3 and is radiated to the outside of the LED bulb 100 by radiation and convection.

  The heat generated by the LED package 16 (LED element 7) is transmitted to the heat sink 3 via the LED mounting base 2, and is radiated to the outside of the LED bulb 100 by radiation and convection.

  In the case where the lattice-shaped heat conducting member 11 is not provided as in the conventional case, the heat conductivity of the globe 1 is about 1 W / (m · K) or less, so that the globe 1 is in contact with the LED mounting base 2. Heat is transmitted only from the part to a few millimeters. For this reason, almost no heat is transmitted to the entire globe 1, and the heat radiation from the globe 1 is extremely small. Therefore, the heat radiation path is mainly only the heat sink 3. Since the globe 1 occupies about 1/3 of the surface area of the LED bulb, about 1/3 of the surface area did not contribute to heat dissipation, and the heat dissipation efficiency was not good.

  In the present embodiment, since the heat conducting member 11 is in thermal contact (connection) with the inner surface side of the globe 1 and the LED mounting base 2, the heat generation of the LED package 16 is conducted through the LED mounting base 2. The heat transferred to the member 11 and further transferred to the heat conducting member 11 is further transferred to the inner surface side of the globe 1 through the adhesive 13. The heat transmitted to the inner surface side of the globe 1 is transmitted to the outer surface side of the globe 1. The thermal conductivity of the globe 1 is 1 W / (m · K) or less, but since the thickness of the globe 1 is about 1 mm, heat is transmitted to the outer surface side of the globe 1. Heat is transmitted from the portion where the heat conducting member 11 and the globe 1 are in thermal contact to the entire globe 1, and the temperature of the globe 1 rises. Although the thermal conductivity of the globe 1 is small, since the lattice spacing of the heat conducting member 11 is optimized, the temperature of the globe 1 surrounded by the lattice is sufficiently increased, and heat is radiated from the globe 1 by radiation and convection. The amount to be increased greatly. Thereby, the heat generated from the LED package 16 can be efficiently released from the globe 1 and the temperature rise of the LED package 16 is suppressed, so that the light emission efficiency of the LED package 16 is improved.

  Next, the traveling path of the light emitted from the LED element 7 will be described. The light emitted from the LED package 16 (LED element 7) is transmitted through the inside of the globe 1 mainly through the air in the globe 1 and is emitted to the outside of the LED bulb 100. A part of the light emitted from the LED package 16 is incident on the surface of the lattice-like heat conducting member 11 through the air in the globe 1, and the light reflected on the surface is transmitted through the inside of the globe 1. Radiated to the outside of the LED bulb 100.

  The ratio of the area of the contact surface 14 of the heat conducting member 11 to the area of the inner surface side of the globe 1 is, for example, about 9.2%. For example, the light incident on the heat conducting member 11 is reflected on the surface of the band having a reflectance of 0.95 and is radiated to the outside of the LED bulb 100. It is about 99.54% (90.8% + 9.2% × 0.95) as compared with the case where it is not provided, and it can be said that there is almost no light loss. Since the luminous efficiency of the LED package 16 is improved by improving the heat dissipation effect, the total luminous flux of the LED bulb 100 is substantially improved.

  In addition, the light reflected by the lattice-shaped heat conducting member 11 diffuses and reaches the back side of the LED bulb 100 (in the direction of the heat sink 3 when viewed from the globe 1), so that the light distribution characteristic is improved. .

  As a result of simulating the heat dissipation effect using the configuration of the first embodiment, when the heat conducting member 11 of the first embodiment is provided, the average temperature of the globe 1 is about 10.5 compared to the case where it is not provided. As a result, the temperature of the main part of the LED bulb 100 was decreased by about 8.5 ° C.

  12, 13, and 14 are perspective views illustrating other examples of the heat conducting member 11. As shown in FIGS. 12 to 14, the lattice-like heat conducting member 11 can appropriately determine the number of lattices in the horizontal direction and the longitudinal direction or the interval between the lattices. Further, the shape of the lattice of the heat conducting member is not limited to these examples, and various shapes can be used.

  In the present embodiment, the belt 1 has a thermal conductivity (for example, 100 W / (m · K) or more) larger than that of the globe 1 (for example, 1 W / (m · K) or less). ˜115 are arranged in a lattice shape, and the heat conducting member 11 is provided which is in contact with the inner surface of the globe 1 with the lattice contact surface 14. Since the heat conductive layer is not provided so as to cover the entire inner surface of the globe 1 as in the prior art, and the heat conductive member 11 has a lattice shape, the LED element 7 ( A reduction in the total luminous flux can be avoided without blocking the light from the LED package 16). In addition, since the heat conducting member 11 having a thermal conductivity larger than that of the globe 1 is in contact with the globe 1, when the heat from the LED element 7 is transmitted to the heat conducting member 11, the heat is also transmitted to the globe 1. The temperature of the globe 1 rises and the radiation effect by radiation and convection from the globe 1 can be enhanced. Thereby, since the heat | fever from LED element 7 is discharge | released efficiently, without disturbing the light emitted from LED element 7, the temperature rise of LED element 7 can be suppressed and the luminous efficiency of LED element 7 improves. Moreover, since it is not necessary to use a large heat sink, the size of the LED bulb 100 can be reduced, and the LED bulb 100 can be attached to an existing lamp, so that the mounting rate of the LED bulb 100 is improved.

  The globe 1 has a dome shape, and the heat conducting member 11 is in contact with the top surface of the globe 1 except for the inner surface. Since the heat conducting member 11 does not exist on the inner surface of the top of the globe 1, that is, the position (surface) facing the LED element 7 of the globe 1, for example, the grid-like heat from the outside with the LED bulb 100 attached to the lamp The conductive member 11 becomes difficult to see. As a result, the glove 1 does not feel light and dark and does not feel uncomfortable. Further, at the top of the globe 1, the heat conduction member 11 does not block the light, and the decrease in the total luminous flux can be suppressed.

(Embodiment 2)
In the first embodiment, the lattice-shaped heat conducting member 11 has a configuration in which an opening 116 is provided at the top of the dome without forming a lattice. That is, the heat conducting member 11 has a configuration that does not cover the portion (top) of the globe 1 at a position facing the LED package 16, but the configuration of the heat conducting member is not limited to this, and the globe 1 is not limited thereto. The structure which covered the whole inner surface of may be sufficient.

  FIG. 15 is a cross-sectional view showing an example of the LED bulb 120 according to the second embodiment, FIG. 16 is a perspective view showing an example of the heat conducting member 21 according to the second embodiment, and FIG. 17 shows the heat of the second embodiment. FIG. 18 is a plan view showing an example of the conductive member 21, and FIG. 18 is a side view showing an example of the heat conductive member 21 of the second embodiment.

  As shown in FIG. 15, the difference between the LED bulb 120 of the second embodiment and the LED bulb 100 of the first embodiment is that a heat conducting member 21 is used instead of the heat conducting member 11. In addition, the same code | symbol is attached | subjected to the location similar to Embodiment 1, and description is abbreviate | omitted.

  As shown in FIGS. 16 to 18, the heat conducting member 21 has a mounting portion 211 for mounting by thermally connecting to the LED mounting base 2 and a plurality of strip-shaped strips 212 and 213. The heat conducting member 21 has nine strips 212 and 213 arranged in a lattice shape, and has a shape that can contact the substantially entire inner surface of the globe 1 with a lattice-shaped contact surface. is there. Specifically, the heat conducting member 21 has a structure in which each of the bands 212 and 213 has a grid of 9 rows by 9 rows along the circumferential direction on the inner surface side of the globe 1. In addition, since the effect of heat conduction from the heat conducting member 21 to the globe 1 increases as the number of grid rows increases, that is, as the grid spacing decreases, it depends on how much the temperature of the LED bulb 120 is suppressed. Thus, the number of grid rows can be adjusted.

  The lattice of the heat conducting member 21 covers the entire inner surface of the globe 1. Thereby, heat can be effectively transmitted to the entire globe 1. Note that only a part of the inner surface side of the globe 1 may be covered as in the first embodiment.

  As in the first embodiment, the heat conducting member 21 is attached to the inner surface side of the globe 1 with an adhesive 13 and is thermally connected. Further, the heat conducting member 21 is thermally connected to the LED mounting base 2 by a heat radiation resin or the like. The material of the heat conducting member 21 is aluminum (A6063), and the surface reflectance is 0.95.

  The width of the contact surface (14) with which the heat conducting member 21 contacts the globe 1 is 0.5 mm, as in the first embodiment. The thickness of the strips 211 and 212 is, for example, 1.0 mm. The thicker the strips 211 and 212, the better the heat dissipation effect.

  The cross-sectional shapes in the short direction of the strips 211 and 212 are the same as those in the example of FIG. That is, the cross-sectional shapes of the strips 211 and 212 form a trapezoid. Moreover, although the cross-sectional shape of the strip | belt bodies 211 and 212 can be made into the shape similar to the shape illustrated in FIG.7, FIG.8, FIG.9, FIG.11 etc., it is not limited to these. By making the cross-sectional shapes of the strips 211 and 212 the same as in the first embodiment, the same effect as in the first embodiment can be obtained.

  In the second embodiment, the ratio of the area of the contact surface on which the lattice-shaped heat conductive member 21 contacts the globe 1 to the area on the inner surface side of the globe 1 is 9.4%, for example. The reflectance of the surface of the heat conducting member 21 is 0.95. Moreover, the cross-sectional shape of the strips 211 and 212 is a trapezoid, and the ratio of light that is reflected by the upper bottom surface (upper bottom surface) and returns to the inside of the LED bulb 120 and is not emitted to the outside is, for example, about 30%. . Under these conditions, the total luminous flux of the LED bulb 120 is 96.85% (90.6% + 9.4% ×) when the heat conducting member 21 is provided, compared with the case where the heat conducting member 21 is not provided. 0.7 × 0.95), and the loss of light is small. Since the luminous efficiency of the LED package 16 is improved by improving the heat dissipation effect, the total luminous flux of the LED bulb 100 is substantially the same or improved.

  In addition, the light reflected by the lattice-like heat conducting member 21 diffuses and reaches the back side of the LED bulb 120 (in the direction of the heat sink 3 when viewed from the globe 1), so that the light distribution characteristic is improved. .

  As a result of simulating the heat dissipation effect using the configuration of the second embodiment, when the heat conducting member 21 of the second embodiment is provided, the average temperature of the globe 1 is about 11.0 compared with the case where it is not provided. As a result, it was found that the temperature of the main part of the LED bulb 120 decreased by about 9.3 ° C.

  19, 20, and 21 are perspective views showing other examples of the heat conducting member 21. As shown in FIGS. 19-21, the lattice-shaped heat conductive member 21 can determine the number of lattices, or the space | interval between lattices suitably. Moreover, the shape of the lattice of the heat conducting member 21 is not limited to these examples, and various shapes can be used.

  In the second embodiment, the belt 1 has a thermal conductivity (for example, 100 W / (m · K) or more) higher than that of the globe 1 (for example, 1 W / (m · K) or less). 213 is arranged in a lattice shape, and includes a heat conducting member 21 that is in contact with the inner surface of the globe 1 with a lattice contact surface (14). Since the heat conducting member 21 has a lattice shape, even when the light transmittance of the heat conducting member 21 is small, it is possible to avoid a decrease in the total luminous flux without blocking the light from the LED element 7 (LED package 16). In addition, since the heat conducting member 21 having a thermal conductivity larger than that of the globe 1 is in contact with the globe 1, when the heat from the LED element 7 is transmitted to the heat conducting member 21, the heat is also transmitted to the globe 1. The temperature of the globe 1 rises and the radiation effect by radiation and convection from the globe 1 can be enhanced. Thereby, since the heat | fever from LED element 7 is discharge | released efficiently, without disturbing the light emitted from LED element 7, the temperature rise of LED element 7 can be suppressed and the luminous efficiency of LED element 7 improves. In addition, since it is not necessary to use a large heat sink, the size of the LED bulb 120 can be reduced, and the LED bulb 120 can be attached to an existing lamp.

  The present invention can be implemented in variously modified forms within the scope of the matters described in the claims.

  As described above, the LED bulb according to the present embodiment has a high heat dissipation effect, and thus has a wide range of applications applicable not only to LED bulbs using LEDs but also to other lighting devices.

1 Globe (Translucent part)
2 LED mounting base (heat sink)
3 Heat sink 4 Insulation ring 5 Base 6 Substrate 7 LED element (light emitting element)
DESCRIPTION OF SYMBOLS 11 Heat conductive member 112, 113, 114, 115 Band 13 Adhesive 14 Contact surface 16 LED package 21 Heat conductive member 212, 213 Band

Claims (9)

In a lighting device comprising: a substrate on which a light emitting element is mounted; and a light transmitting element that covers the light emitting element and the substrate and transmits light from the light emitting element.
One of the longitudinal side end portions of the band arranged in a lattice shape is in contact with the inner surface of the light transmitting portion, and includes a heat conducting member that conducts heat of the light emitting element,
The illuminating device characterized in that the heat conductivity of the heat conducting member is greater than the heat conductivity of the light transmitting part. A heat sink on which the substrate is placed;
The lighting device according to claim 1, wherein the heat radiating plate and the heat conducting member are thermally connected. The translucent part has a dome shape,
The heat conducting member is
The lighting device according to claim 1, wherein the lighting device is in contact with the inner surface of the translucent portion except for the inner surface of the top portion. The thickness of the band is
The lighting device according to any one of claims 1 to 3, wherein the lighting device is gradually thinned from one of the longitudinal side end portions to the other direction.   The lighting device according to claim 4, wherein a cross-sectional shape of the belt in a short direction is a triangular shape.   The lighting device according to claim 4, wherein a cross-sectional shape of the belt in a short direction is a trapezoidal shape.   7. The lighting device according to claim 1, wherein a width of a contact surface of the belt body with the translucent portion is not less than 0.5 mm and not more than 1.0 mm. .   The lighting device according to any one of claims 1 to 7, wherein the heat conductivity of the heat conducting member is 100 W / (m · K) or more.   The illumination device according to any one of claims 1 to 8, wherein a reflectance of the heat conducting member is 0.9 or more.

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