JP2013020813A - Electric bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light bulb that can be expected to sufficiently suppress the temperature rise of a semiconductor light emitting element that generates heat in a light emitting state.
A light bulb includes a main body, a light source, and a globe. The main body 2 is made of metal and has a light source mounting portion 4. The light source 7 includes a light emitting unit 9 including an LED (semiconductor light emitting element) 9a that generates heat in a light emitting state, and a light source substrate 8 on which the light emitting unit 9 is mounted. The light source 7 is attached to the light source mounting part 4 by bringing the light source substrate 8 into contact with the light source mounting part 4. The globe 11 is formed of a globe body 12 and a light guide portion 13 each made of a light-transmitting and highly heat-conductive material. The light guide 13 is thermally coupled to the central portion of the globe body 12 and protrudes into the globe body 12. The globe body 12 is disposed so as to cover the light source 7 and the light source mounting portion 4. The light emitting unit 9 is accommodated in the protruding tip portion 13 b of the light guide portion 13, and the protruding tip portion 13 b is thermally coupled to the light source substrate 8.
[Selection] Figure 1

Description

  Embodiments described herein relate generally to a light bulb including a globe.

  Attach the light source board on which the LED is mounted to the surface of the light source mounting part that the cover that is a metal outer member has, and attach a light-transmitting glove that covers the light source board made of transparent glass or the like that is formed into a substantially spherical shape A light bulb having a configuration in which a light guide that is attached to a portion and covers an LED is disposed on a light source substrate, and a front end surface of the light guide is opposed to an inner surface of a central portion of a globe is known as a related art.

  Most of the heat generated by the light-emitting LED is transmitted to the outer member via the light source substrate, and is released into the atmosphere from the periphery of the outer member. Thereby, since the temperature rise of LED is suppressed, the luminous efficiency of LED, emission color maintenance, etc. are achieved.

  In recent years, the output of LEDs has been increasing, and the amount of heat generated by LEDs has increased. For this reason, the case where it becomes difficult to fully suppress the temperature rise of LED is considered. Furthermore, when the shape of the light bulb is small, the surface area of the outer member provided in the light bulb, that is, the heat radiation area is small, and it becomes difficult to sufficiently suppress the temperature rise of the LED.

JP 2009-289697 A

  An embodiment is to provide a light bulb that can be expected to sufficiently suppress a temperature rise of a semiconductor light emitting element that generates heat in a light emitting state.

  In order to solve the above-described problem, the light bulb of the embodiment includes a main body, a light source, and a globe. The main body is made of metal and has a light source mounting portion. The light source includes a light emitting unit including a semiconductor light emitting element that generates heat in a light emitting state, and a light source substrate on which the light emitting unit is mounted. The light source board is brought into contact with the light source mounting portion, and the light source is mounted on the light source mounting portion. The globe is formed of a globe body and a light guide portion, both of which are translucent and made of a highly thermally conductive material. The light guide is thermally coupled to the center of the globe body and protrudes into the globe body. A glove body is disposed to cover the light source and the light source mounting portion. The light emitting part is accommodated in the protruding tip part of the light guide part, and the protruding tip part is thermally coupled to the light source substrate.

  According to the light bulb of the embodiment, the effect that the temperature rise of the semiconductor light emitting element that generates heat in the light emitting state can be sufficiently suppressed can be expected.

It is sectional drawing which shows the LED light bulb which concerns on Example 1. FIG. 6 is a cross-sectional view showing an LED bulb according to Example 2. FIG.

  The light bulb of Embodiment 1 has a metal main body having a light source mounting portion; a light emitting portion including a semiconductor light emitting element that generates heat in a light emitting state; and a light source substrate on which the light emitting portion is mounted. A light source mounted on the light source mounting portion in contact with the mounting portion; a glove body made of a light-transmitting and highly heat-conductive material and disposed over the light source and the light source mounting portion; It is made of a material having high thermal conductivity and is thermally coupled to the central portion of the globe body so as to protrude inside the globe body, and a projecting tip portion accommodates the light emitting portion and is thermally applied to the light source substrate. And a globe having a light guide unit coupled thereto.

  In the first embodiment, the metal forming the main body can be preferably aluminum or an alloy thereof, but other metals can also be used. At the same time, the main body has a structure in which the light source mounting portion is integrally formed, or the light source mounting portion is formed separately from the main body main portion, and the light source mounting portion and the main body main portion are connected. The main body of the configuration may be used.

  In the first embodiment, an LED (light emitting diode) or a semiconductor laser can be used as the semiconductor light emitting element. In the first embodiment, the light source substrate can be preferably a metal base substrate having a metal base plate that forms the back surface of the substrate, but instead of this, a single insulating plate or a laminated substrate is used. An insulating plate or the like can also be used.

  In the first embodiment, as a material forming the globe body and the light guide unit, ceramic, synthetic resin, glass, or the like can be used as long as it is a light-transmitting material having high thermal conductivity. In the first embodiment, the glove body is preferably substantially hemispherical or substantially spherical in order to ensure a large surface area, but is not limited thereto.

  In the first embodiment, the fact that the light guide is thermally coupled to the central part of the globe body means that both of them are connected in a thermally conductive state. For example, the light guide is a globe. An aspect in which the main body is formed integrally with the main body and an aspect in which the light guide portion is in close contact with the glove main body can be given. In the case of the latter aspect, in order to make it difficult for air to remain between a light guide part and a globe main body, you may interpose an adhesive agent and a heat-transfer layer between both. The adhesive used in this configuration is preferably an adhesive having good thermal conductivity such as a silicone-based adhesive. Examples of the material forming the heat transfer layer include silicone resin and grease.

  Similarly, in the first embodiment, the protruding tip portion of the light guide portion is thermally coupled to the light source substrate means that both of them are connected in a thermally conductive state. A mode in which the tip portion is in close contact with the light source substrate can be exemplified. In this case, in order to make it difficult for air to remain between the protruding tip and the light source substrate, an adhesive or a heat transfer layer may be interposed therebetween. The adhesive used in this configuration is preferably an adhesive having good thermal conductivity such as a silicone-based adhesive. Examples of the material forming the heat transfer layer include silicone resin and grease.

  In the first embodiment, the translucent globe is made of a material having high thermal conductivity, and the globe has a light guide portion that is thermally coupled to the light source substrate, and the light guide portion is heated on the globe body. Combined. For this reason, the heat generated by the semiconductor light emitting element of the light source in the lighting state of the light bulb is transmitted from the light source substrate to the globe body via the light guide, and is released from the surface of the globe body to the atmosphere. In addition to this, the heat generated by the semiconductor light emitting element of the light source when the light bulb is turned on is transmitted from the light source substrate to the light source mounting portion of the main body and released from the surface of the main body into the atmosphere.

  Since the light bulb of the first embodiment that can radiate heat from both the main body and the globe has a large heat radiation area to the outside, the shape of the light bulb is small even when a semiconductor light emitting device that generates a large amount of heat is used. Even in this case, it can be expected that the temperature rise of the semiconductor light emitting device is sufficiently suppressed.

  The light bulb of the second embodiment is characterized in that, in the first embodiment, the globe main body and the light guide section are integrally formed.

  In Embodiment 2, since the thermal resistance between the globe body and the light guide portion is small and heat transfer from the light guide portion to the globe body is easy in Embodiment 1, the surface of the globe body is in the atmosphere. It is possible to improve the release performance.

  The light bulb of the third embodiment is characterized in that, in the first embodiment, the light guide section is separate from the globe body.

  In this Embodiment 3, since the glove body and the light guide are separately formed in Embodiment 1, the following advantages can be expected. For example, in the case where a part responsible for the lens function or a part responsible for the light diffusion function around the light guide part is formed in the light guide part and a desired function is added to the light guide part, the light guide part is integral with the glove body. Compared to the configuration, since there is no portion that becomes an undercut when molding the globe body and the light guide, the moldability is good.

  A light bulb according to a fourth embodiment includes a lens unit that controls light transmitted through the light guide unit at a base end portion of the light guide unit that is thermally coupled to the globe body according to any one of the first to third embodiments. It is characterized by being provided.

  In the fourth embodiment, in the first to third embodiments, the light emitted from the central portion of the globe body in the light use direction is condensed by the lens portion of the light guide portion that guides the light emitted from the light emitting portion to the globe body. Alternatively, it can be diffused to obtain a predetermined light distribution.

  The light bulb of Embodiment 5 is characterized in that, in any of Embodiments 1 to 4, the globe body and the light guide section are made of ceramics.

  In the fifth embodiment, since the thermal conductivity of the globe is higher in any of the first to fourth embodiments, the temperature rise of the semiconductor light emitting element is sufficiently suppressed by the heat radiation from the surface of the globe to the atmosphere. It is possible.

  Hereinafter, the light bulb of Example 1 will be described in detail with reference to FIG.

  The light bulb 1 includes a metal main body 2, a light source 7, a globe 11, an insulating member 21, a lighting circuit 25, and a base 31.

  The main body 2 is made of, for example, an integrally formed product of aluminum or an alloy thereof. The main body 2 has a peripheral wall 3 and a light source mounting portion 4. The peripheral wall 3 has a cylindrical shape, and its outer peripheral surface is used as a heat radiating surface. The diameter of the peripheral wall 3 is gradually reduced as the distance from the light source mounting portion 4 increases. The peripheral wall 3 that forms the peripheral portion of the main body 2 may have a plurality of heat dissipating fins protruding outward in order to increase the heat dissipating area. The light source mounting portion 4 is formed integrally with the peripheral wall 3 so as to close one end of the peripheral wall 3 in the axial direction. The surface 4a of the light source mounting portion 4 is a flat surface. The main body 2 has a recess 5 formed by being surrounded by the peripheral wall 3 and the light source mounting portion 4. The recess 5 is open to the other axial end of the peripheral wall 3.

  The light source 7 is composed of a light emitting module formed by mounting a light emitting unit 9 at the center of a light source substrate 8 having a substantially circular or rectangular shape, for example.

  Although not shown, for example, the light source substrate 8 is formed by laminating an insulating layer on one surface of a metal base plate, forming a wiring pattern on the insulating layer, and on the insulating layer and the wiring pattern except for a predetermined portion of the wiring pattern. It consists of a printed wiring board having an insulating thin resist layer deposited. The base plate forming the back surface of the light source substrate 8 is made of aluminum, an alloy thereof, iron, copper, or the like. The insulating layer is made of synthetic resin or ceramics. Further, instead of the base plate and the insulating layer, it is possible to use a single ceramic insulating plate.

  Furthermore, the wiring pattern is made of, for example, copper foil. This wiring pattern integrally has a heat spreader portion for spreading the heat of the LED 9a, which will be described later, over substantially the entire area of the light source substrate 8. The heat spreader portion reaches the vicinity of the peripheral edge portion of the light source substrate 8 and is covered with a resist layer.

  The light emitting unit 9 is composed of, for example, a COB (chip on board) type light emitting module. That is, the light emitting unit 9 is formed to include a plurality of LEDs 9a, a frame 9b, and a sealing member 9c.

  Each LED 9a is formed of a bare chip and is mounted on the light source substrate 8 while being electrically connected to the wiring pattern. For example, LEDs 9a that emit blue light are used as the LEDs 9a. The frame 9b is bonded to the light source substrate 8 and surrounds the LED 9a group. The sealing member 9c is electrically insulating and translucent, and fills the frame 9b by filling the LED 9a and the like.

  A phosphor (not shown) is mixed in the sealing member 9c. As the phosphor, a yellow phosphor that is excited by light emitted from the LED 9a and emits yellow light is used. Therefore, the light emitting unit 9 emits white light in which yellow light emitted from the phosphor and blue light emitted from the LED 9a are mixed. Note that a light emitting module such as an SMD type may be used for the light emitting unit 9.

  Since the light emitting unit 9 included in the light source 7 includes the LED 9a, the light source 7 is an LED light source, and the light bulb 1 including the light source 7 is an LED light bulb. Since the light emission of the LED 9a is realized by passing a forward current through a pn junction of a semiconductor, the LED directly converts electric energy into light. A semiconductor light emitting device such as an LED that emits light based on such a light emission principle has an energy saving effect as compared with an incandescent bulb that incandescents a filament to a high temperature by energization and emits visible light by its thermal radiation.

  The light emitting unit 9 is mounted in the central region of the light source mounting part 4 with the back surface of the light source substrate 8 being in close contact with the front surface 4 a of the light source mounting part 4.

  The globe 11 includes a globe body 12 and a light guide portion 13.

  The globe body 12 is hollow and substantially hemispherical, and preferably has a hemispherical shape corresponding to a half of a hollow sphere, and the diameter of the circular end surface is substantially equal to the diameter of the light source mounting portion 4. The globe body 12 is made of a light-transmitting material having high thermal conductivity, such as a light-transmitting ceramic. Here, the globe 11 may be transparent, but is preferably diffusive and translucent. Further, the high thermal conductivity of the globe 11 means that the thermal conductivity is higher than that of an acrylic resin or a polycarbonate resin that is a constituent material of a general synthetic resin globe. .

  The light guide unit 13 is formed of a light-transmitting material having high thermal conductivity, for example, the same light-transmitting ceramic as the globe body 12, similar to the globe body 12. The light guide unit 13 protrudes from the center of the globe body 12 into the globe body 12. The light guide unit 13 and the globe body 12 are bonded to each other with a heat conductive adhesive (not shown), for example, a silicone adhesive, interposed between the light guide unit 13 and the globe body 12. And are thermally coupled.

  The light guide portion 13 is a solid columnar shape with a circular outer periphery, and distributes light emitted through the center of the globe 11 to the base end portion 13 a continuous to the inner surface of the center portion of the globe body 12. A lens unit 14 to be controlled is formed. The lens portion 14 is provided on the central axis of the light guide portion 13 and is recessed with respect to the base end portion 13 a, but its opening is closed at the central portion of the globe body 12. For this reason, dust does not adhere to the lens part 14 which consists of a dent.

  A light receiving recess 15 is formed at the end of the light guide 13 opposite to the base end 13a, that is, at the protruding tip 13b. The light receiving recess 15 is sized to accommodate the light emitting portion 9, and the bottom surface of the light receiving recess 15 is a light incident surface.

  Furthermore, the light guide part 13 has a constricted part 13c at the center part in the axial direction. By this constricted portion 13 c, a part of the light guided in the light guide portion 13 is emitted around the light guide portion 13. In addition, when the transparency of the light guide unit 13 is lower than that of transparent glass, light can be emitted around the light guide unit 13 even if the light guide unit 13 does not have the constricted part 13c. Is possible.

  Although the globe 11 has the constricted portion 13c in the light guide portion 13 as described above, the globe main body 12 and the light guide portion 13 are separately formed, so that the guide having the constricted portion 13c is formed. Compared to the configuration in which the light portion 13 is integrally formed with the globe body 12, the constricted portion 13c is not undercut when the globe body 12 and the light guide portion 13 are formed using a mold. For this reason, the globe body 12 and the light guide portion 13 can be easily formed.

  The globe 11 is disposed so as to cover the light source mounting portion 4 and the light source 7. For this purpose, the opening edge of the globe main body 12 is bonded to the peripheral portion of the light source mounting portion 4 and supported by the main body 2. In addition, the protruding tip portion 13b of the light guide portion 13 accommodates the light emitting portion 9 in the light receiving concave portion 15 and is bonded to the light source substrate 8 around the light emitting portion 9, and the main body through the light source substrate 8 2 is supported. As an adhesive (not shown) that bears these adhesions, it is preferable to use a highly heat conductive adhesive such as a silicone adhesive. The light guide portion 13 and the globe body 12 are thermally coupled at the bonding portion between the light source substrate 8 and the protruding tip portion 13b. In order to secure a larger area for the thermal coupling, it is desirable that the protruding tip 13b is bonded to the peripheral portion 8a so as to overlap substantially the entire peripheral portion 8a of the light source substrate 8.

  As described above, the glove 11 can be supported on the main body 2 with a simple configuration without requiring parts for supporting the glove 11 on the main body 2. Furthermore, in addition to adhering and supporting the opening edge of the globe body 12 to the body 2, the light guide portion 13 is also adhered to the light source substrate 8, so that the support performance of the globe 11 is improved. For this reason, even if a defective portion occurs in the adhesion between the opening edge of the globe body 12 and the body 2, there is no possibility that the support of the globe 11 becomes unstable due to this.

  The insulating member 21 is formed in a cup shape, and is disposed along the inner surface of the recess 5 in order to electrically insulate between the main body 2 and a lighting circuit 25 described later.

  The lighting circuit 25 that emits light from each LED 9 a included in the light source 7 is unitized by attaching various circuit components 27 to a circuit board 26. The lighting circuit 25 is accommodated in the recess 5 of the main body 2 and inside the insulating member 21. The circuit board 26 is electrically connected to the light source board 8 via an insulating coated electric wire (not shown) that penetrates the insulating member 21 and the light source mounting portion 4.

  A base 31 that supplies power to the lighting circuit 25 includes a base body 32 and a connecting member 33. The base body 32 is detachably screwed into a power supply socket (not shown). The connecting member 33 is formed of an electrical insulating material such as synthetic resin and is fixed to the base body 32. The connecting member 33 is connected to the opening end of the recess 5 of the main body 2. An insulating coated wire (not shown) that is electrically connected to the lighting circuit 25 is connected to the inner surface of the base body 32.

  In the light bulb 1 configured as described above, each LED 9 a included in the light emitting unit 9 of the light source 7 emits light when the lighting circuit 25 is energized with the base 31 connected to a power supply socket (not shown). Thereby, the white light emitted from the light emitting unit 9 passes through the globe 11 and is provided for illumination. In this case, the light emitted from the light emitting unit 9 is guided to the central part of the globe body 12 by the light guide unit 13 and is emitted from around the light guide unit 13 to reach the inner surface of the globe body 12. The whole 12 becomes bright.

  Each LED 9a emits heat in the lighting state of the light bulb 1, and this heat is transmitted to the light source substrate 8, from which the main body 2, a globe body 12 made of a translucent material having high thermal conductivity, and a light guide section 13 are formed. It is transmitted to the globe 11 and discharged from the surface of the main body 2 and the surface of the globe 11 into the atmosphere.

  That is, the heat generated by each LED 9 a is transmitted from the light source substrate 8 to the light source mounting portion 4 and released from the peripheral portion of the main body 2 into the atmosphere.

  At the same time, the light guide portion 13 included in the globe 11 is thermally coupled by being bonded to the light source substrate 8 and sandwiches the light source substrate 8 with the light source mounting portion 4. For this reason, the heat generated by each LED 9 a is transmitted from the light source substrate 8 to the light guide portion 13, and is conducted to the central portion of the globe body 12 via the light guide portion 13. Accordingly, the heat is conducted to the entire area of the globe body 12 and is released from the surface of the globe body 12 to the atmosphere.

  In such heat conduction, the peripheral portion 8a of the light source substrate 8 is provided with a heat spreader portion (not shown) composed of a part of the wiring pattern as described above, and the light guide unit 9 surrounds the light emitting portion 9 with the peripheral portion 8a. The protruding tip portion 13b of the portion 13 is in contact. For this reason, it is possible to efficiently transmit the heat diffused to the heat spreader portion among the heat generated by each LED 9 a to the light guide portion 13.

  The opening edge of the globe body 12 is also thermally coupled by being bonded to the light source mounting portion 4. For this reason, a part of the heat that is emitted from the light source 7 to the light source mounting portion 4 and is transmitted to the peripheral portion of the main body 2 is conducted to the globe main body 12 via the bonding portion between the globe main body 12 and the light source mounting portion 4. And released from the surface of the globe body 12 into the atmosphere.

  As described above, the light bulb 1 capable of radiating heat from both the main body 2 and the globe 11 can ensure a large heat radiating area to the atmosphere according to the surface area of the globe body 12. In addition, since the globe body 12 is substantially hemispherical and has a larger surface area, the heat dissipation from the surface of the globe body 12 to the atmosphere is further improved.

  Therefore, even when the amount of heat generated by the LED 9a included in the light source 7 is large, even when the shape of the bulb 1 is small, or both of these are satisfied, it is expected to sufficiently suppress the temperature rise of each LED 9a. it can.

  FIG. 2 shows a second embodiment. The second embodiment is different from the first embodiment in the configuration described below, and the other configurations are the same as those in the first embodiment. Therefore, the configuration having the same or similar functions as the first embodiment is described in the first embodiment. The same reference numerals as those in FIG.

  In the light bulb 1 of the second embodiment, a light guide portion 13 that protrudes to the inside of the globe body 12 is integrally formed in the center portion of the globe body 12 and a lens formed at the base end portion 13 a of the light guide portion 13. Unlike the first embodiment, the other configuration of the light bulb 1 of the second embodiment is the same as that of the first embodiment in that the portion 14 is opened to the surface of the central portion of the globe 11.

  Therefore, also in this Example 2, the said subject is solved for the reason demonstrated in Example 1, and the light bulb 1 which can anticipate suppressing the temperature rise of LED9a which generate | occur | produces heat | fever in a light emission state fully is provided. Is possible.

  In Example 2, the light guide unit 13 is divided at the portion having the minimum diameter by the constricted part 13c, so that the light guide unit 13 is integrated with the globe main body 12 and the proximal end side light guide member; You may form with two members with the protrusion edge part side light guide member adhere | attached on this with the adhesive agent. In this way, when the globe 11 is molded, the constricted portion 13c does not become an undercut portion, so that the moldability of the globe can be improved.

  DESCRIPTION OF SYMBOLS 1 ... Light bulb, 2 ... Main body, 4 ... Light source attachment part, 4a ... Surface of light source attachment part, 7 ... Light source, 8 ... Light source board | substrate, 9 ... Light emission part, 9a ... LED (semiconductor light emitting element), 11 ... Globe, 12 ... Globe body, 13 ... Light guide part, 13a ... Base end part, 13b ... Projection tip part, 15 ... Concave part

Claims (5)

A metal body having a light source attachment;
A light emitting unit including a semiconductor light emitting element that generates heat in a light emitting state, and a light source substrate on which the light emitting unit is mounted, and a light source mounted on the light source mounting unit by contacting the light source substrate with the light source mounting unit;
A globe body made of a light-transmitting and highly heat-conductive material and disposed so as to cover the light source and the light source mounting portion; A glove having a light guide portion coupled and projecting inside the globe body and having a projecting tip portion accommodating the light emitting portion and thermally coupled to the light source substrate;
A light bulb characterized by comprising:   The light bulb according to claim 1, wherein the globe main body and the light guide portion are integrally formed.   The light bulb according to claim 1, wherein the light guide unit is separate from the globe body.   The lens part which controls the light which permeate | transmits the said light guide part is provided in the base end part of the said light guide part thermally couple | bonded with the said globe main body among Claim 1 to 3 characterized by the above-mentioned. The light bulb as described in any one of.   The bulb according to any one of claims 1 to 4, wherein the globe body and the light guide section are made of ceramics.

Images