Patent Publication Number: US-2015085486-A1

Title: Lamp Device and Luminaire

Description:
INCORPORATION BY REFERENCE 
     The present invention claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2013-195744 filed on Sep. 20, 2013. The content of the application is incorporated herein by reference in their entirety. 
     FIELD 
     Embodiments described herein relate generally to a lamp device in which heat generated by a light-emitting module is radiated to the outside, and a luminaire using the lamp device. 
     BACKGROUND 
     Hitherto, a flat lamp device such as, for example, a lamp device using a GH76p cap is proposed. In this lamp device, a light-emitting module and a lighting device are arranged in a housing provided with an opening part at one end side, and a thermal radiation member is attached to the other end side of the housing. The light-emitting module is thermally connected to the thermal radiation member. Heat generated by the light-emitting module is conducted to the thermal radiation member, and is conducted and radiated from the thermal radiation member to a luminaire side. 
     Besides, there is a lamp device in which a light-emitting module is arranged to be close to an opening part side of a housing in order to improve the light extraction efficiency of the lamp device. In this lamp device, the light-emitting module is distant from a thermal radiation member. Thus, a metal support member separate from the thermal radiation member is used, the light-emitting module is connected to and supported at one end side of the support member, and the other end side of the support member is connected and attached to the thermal radiation member. As a result, a heat conduction path from the light-emitting module to the thermal radiation member is secured. An attachment portion for attaching the light-emitting module is integrally protruded from the periphery at the one end side of the support member. 
     However, when the attachment portion for attaching the light-emitting module is integrally protruded from the periphery at the one end side of the metal support member, the distance between the attachment portion and a lighting device becomes short, and there occurs a problem in securing insulation properties. Besides, if an insulator is used for the attachment of the light-emitting module in order to solve the problem of securing the insulation properties, there is a fear that thermal radiation properties from the light-emitting module deteriorate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a lamp device of an embodiment. 
         FIG. 2  is a sectional view of a part of the lamp device. 
         FIG. 3  is a perspective view of a decomposed state of the lamp device. 
         FIG. 4  is a perspective view of the lamp device. 
         FIG. 5  is a perspective view of the lamp device. 
         FIG. 6  is a sectional view of a luminaire using the lamp device. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, a lamp device includes a housing, a light-emitting module, a lighting device, a thermal radiator and an attachment base. The housing includes an opening part at one end side, a closing part at the other end side and an insertion part formed at a center of the closing part. The light-emitting module is arranged in the housing to emit light from the opening part. The lighting device is arranged to be closer to the closing part side than the light-emitting module in the housing, and includes a circuit board arranged around the insertion part. The thermal radiator includes a support part inserted through the insertion part, a light-emitting module connection part which is provided at one end side of the support part and to which the light-emitting module is thermally conductively connected, and an external thermal radiation part provided at the other end side of the support part. The attachment base is made of an insulating material and is arranged around the light-emitting module connection part. An attachment surface facing the light-emitting module is provided at one end side of the attachment base, and the light-emitting module connection part protrudes from the attachment surface. The attachment base supports the light-emitting module connected to the light-emitting module connection part, and is thermally connected thereto. 
     As stated above, the insulating attachment base is arranged around the light-emitting module connection part of the thermal radiator. Thus, the light-emitting module can be attached, and insulation properties against the lighting device can be secured. Further, since the light-emitting module connection part protrudes from the attachment base, the light-emitting module certainly contacts the light-emitting module connection part, and excellent thermal radiation properties can be secured. 
     Hereinafter, an embodiment will be described with reference to  FIG. 1  to  FIG. 6 . 
     As shown in  FIG. 6 , a luminaire  10  is an embedded-type luminaire such as a downlight. The luminaire  10  includes a flat lamp device  11 , and an equipment device  12  on which the lamp device  11  is detachably and attachably mounted. 
     As shown in  FIG. 1  to  FIG. 5 , the lamp device  11  includes a housing  20 , a thermal radiator  21 , an attachment base  22 , a light-emitting module  23 , a reflector  24 , a lighting device  25  and a translucent cover  26 . Incidentally, in the following description, one end side of the lamp device  11 , which is a light irradiation side, is a lower side, and the other end side thereof, which is an opposite side to the light irradiation direction, is an upper side. 
     The housing  20  is formed of an insulating material, such as synthetic resin, into a cylindrical shape, and includes a peripheral part  28 , an opening part  29  at the lower side of the peripheral part  28 , and a closed part  30  at the upper side of the peripheral part  28 . A cylindrical insertion part  32  forming an insertion port  31  opened in an up-and-down direction is protrudingly provided at the center of the closing part  30  in the housing  20 . An annular protrusion  33  to which the thermal radiator  21  is attached is upward protrudingly provided between the peripheral part of the closing part  30  and the insertion part  32 . A circuit board placing part  34  on which the lighting device  25  (circuit board  70 ) is positioned and placed is formed inside the housing  20  and at the peripheral part of the closing part  30  and the outer peripheral part of the insertion part  32 . Further, a locking part  35  to lock the lighting device  25  (the circuit board  70 ) is provided between the outer peripheral part of the insertion part  32  and the circuit board placing part  34 . 
     Besides, the thermal radiator  21  is integrally formed of a metal material such as aluminum die cast. The thermal radiator  21  includes a cylindrical support part  37 , a light-emitting module connection part  38  formed at the lower side of the support part  37 , and an external thermal radiation part  39  formed at the upper side of the support part  37 . 
     A columnar part  40  insertable into the insertion part  32  is formed at the lower side of the support part  37 , and a step part  41  is formed around the lower periphery of the columnar part  40 . A taper part  42  whose sectional area increases toward the upper external thermal radiation part  39  is formed at the upper side of the support part  37 . An inclination angle of the taper part  42  is set to, for example, 45°. 
     The light-emitting module connection part  38  is a circular contact surface formed to be flat on the tip surface of the support part  37 , and an area thereof is smaller than a sectional area of the support part  37  and is smaller than an area of the external thermal radiation part  39 . 
     The external thermal radiation part  39  is formed into a disk shape larger than the support part  37  and the light-emitting module connection part  38 , and is arranged on the protrusion  33  in a state where the peripheral part protrudes from the protrusion  33  in an outer diameter direction. A plurality of key grooves  44  and a plurality of keys  45  are disposed at specified positions on the peripheral part of the external thermal radiation part  39 . A thermal conductive sheet  46  is attached to the upper surface of the external thermal radiation part  39 . 
     A plurality of bosses  47  for screwing the attachment base  22  is provided around the support part  37 , and a plurality of bosses  48  for screwing to the housing  20  is provided on the peripheral part of the external connection part  39 . A plurality of screws  49  is screwed to the plurality of bosses  48  of the thermal radiator  21  from the inside of the housing  20 , so that the housing  20  and the thermal radiator  21  are fixed. 
     A cap part  50  having a specified standard size is constructed of the upper side including the protrusion  33  of the housing  20 , the external thermal radiation part  39  of the thermal radiator  21  and the like. 
     The attachment base  22  is made of an insulating material such as synthetic resin. A hole part  52  through which the light-emitting module connection part  38  is inserted is formed at the center of the attachment base  22 . A plurality of attachment holes  53  for screwing to the thermal radiator  21  is formed in the peripheral part of the attachment base  22 , and a plurality of attachment holes  54  for screwing the reflector  24  is formed. In a state where the light-emitting module connection part  38  is inserted through the hole part  52 , and the attachment base  22  is arranged around the light-emitting module connection part  38 , a plurality of screws  55  is screwed to the plurality of bosses  47  of the thermal radiator  21  from the attachment holes  53 , so that the attachment base is fixed to the thermal radiator  21 . In the state where the attachment base  22  is fixed to the thermal radiator  21 , the light-emitting module connection part  38  protrudes from an attachment surface  22   a  of the attachment base  22 . A protrusion amount h of the light-emitting module connection part  38  from the attachment surface  22   a  of the attachment base  22  is small, and is preferably smaller than, for example, the thickness of a board  58  of the light-emitting module  23 . 
     The light-emitting module  23  includes a plurality of light-emitting elements  57 , and the board  58  on which the plurality of light-emitting elements  57  are mounted. 
     For example, an SMD (Surface Mount Device) package is used for the light-emitting elements  57 . The light-emitting elements  57  are closely arranged on the board  58  in an arbitrary arrangement. Incidentally, a COB (Chip On Board) system in which a plurality of LED chips is mounted on the board  58  and is integrally sealed with sealing resin containing phosphor may be used for the light-emitting elements  57 , or another semiconductor light-emitting element such as an EL element may be used. 
     The board  58  is made of a material such as, for example, metal, ceramic or resin having excellent thermal conductivity. A pattern for electrically connecting the light-emitting elements  57  is formed on the mount surface of the board  58  on which the light-emitting elements  57  are mounted. A connector  59  for electrically connecting the lighting device  25  is mounted on the pattern of the board  58 . 
     The back side of the board  58  of the light-emitting module  23  is arranged to contact the light-emitting module connection part  38  and the attachment base  22  through an insulating sheet which is also a heat conductive sheet. The plural light-emitting elements  57  are arranged in a region of the light-emitting module connection part  38  when viewed from below. 
     The insulating sheet  60  has heat conductivity and insulation properties as well as elasticity, and is formed to be larger than the light-emitting module connection part  38  and the board  58 . When the insulating sheet  60  is sandwiched between the light-emitting module connection part  38  and the board  58  and between the attachment base  22  and the board  58 , a step difference between the light-emitting module connection part  38  and the attachment base  22  is absorbed by a difference in compression amount of the insulating sheet  60 , and the application of stress to the light-emitting module  23  is relieved. 
     The reflector  24  is made of an insulating material such as synthetic resin. A window hole  62  which is smaller than the outer shape of the board  58  and through which the light-emitting elements  57  can be inserted is formed at the center of the reflector  24 . A recessed positioning part  63  in which the board  58  is fitted to be positioned is formed on the upper surface of the reflector  24 . A reflecting surface  64  expanding downward from the peripheral edge part of the window hole  62  to the peripheral part of the reflector  24  is formed. A plurality of support pieces  65  supported by the housing  20  is provided at the peripheral part of the reflector  24 . A plurality of attachment holes  66  for screwing the reflector  24  to the attachment base  22  is formed in the reflecting surface  64 . 
     Screws  67  inserted through the attachment holes  66  are screwed and fastened to the attachment holes  54  of the attachment base  22 , so that the board  58  is held in the state where the board is pressed to the light-emitting module connection part  38 . At this time, the insulating sheet  60  sandwiched between the light-emitting module connection part  38  and the board  58  and between the attachment base  22  and the board  58  is compressed. Thus, the step difference between the light-emitting module connection part  38  and the attachment base  22  is absorbed by the difference in compression amount of the insulating sheet  60 , and the application of stress to the light-emitting module  23  is relieved. The reflector  24  is arranged between the opening part  29  of the housing  20  and the light-emitting module  23 , and covers the lighting device  25  so that light of the light-emitting elements  57  is not irradiated to the lighting device  25 . 
     The lighting device  25  includes, for example, a power supply circuit to rectify and smooth commercial AC power and to convert into DC power, a DC/DC converter to supply the DC power as specified DC output to the LED elements by switching of a switching element and to light the LED elements, and a control IC to control the oscillation of the switching element. In the case of the dimming lighting device  25 , a function is provided in which a current of the light-emitting element  57  is detected and is compared with a reference value corresponding to a dimming signal, and the control IC controls the switching operation of the switching element. 
     The lighting device  25  includes the circuit board  70  and circuit parts  71  as a plurality of electronic parts mounted on the circuit board  70 . 
     The circuit board  70  is formed into an annular shape, and a circular fitting hole  72  through which the insertion part  32  of the housing  20  is inserted is formed at the center of the circuit board  70 . A lower surface of the circuit board  70  is a mount surface  70   a  on which a lead part having a lead wire among the circuit parts  71  is mounted. An upper surface thereof is a wiring surface  70   b  as a wiring pattern surface or a solder surface provided with a wiring pattern to which the lead wire of the lead part is connected by soldering and on which a surface mount part among the circuit parts  71  is mounted. 
     The circuit board  70  is arranged at the upper position in the housing  20  in a state where the wiring surface  70   b  is directed upward and faces the closing part  30  of the housing  20 . The circuit parts  71  mounted on the mount surface  70   a  of the circuit board  70  is arranged among the peripheral part  28  of the housing  20 , the insertion part  32 , the attachment base  22  and the reflector  24 . 
     A power input side of the circuit board  70  is electrically connected to a pair of lamp pins  73  for power supply, and a lighting output side is electrically connected to the light-emitting module  23 . The pair of lamp pins  73  for power supply protrudes vertically from the closing part  30  of the housing  20 . Incidentally, in the case of the dimming lighting device  25 , in addition to the lamp pins for power supply, a plurality of lamp pins  73  for dimming also protrudes vertically from the closing part  30  of the housing  20 . 
     The translucent cover  26  is formed into a disk shape from a synthetic resin having translucency, and is attached to the housing  20  so as to cover the opening part  29 . A Fresnel lens  75  for controlling the light emitted from the lamp device  11  to obtain a specified luminous intensity distribution is formed on the inner surface (upper surface) of the translucent cover  26  facing the light-emitting module  23 . The Fresnel lens  75  has a saw-like sectional shape in the diameter direction and is formed concentrically. A finger hook part  76  to facilitate the rotation operation of the lamp device  11  attached to and detached from the equipment device  12  (socket) is protrudingly provided at the lower surface peripheral part of the translucent cover  26 . Incidentally, the Fresnel lens  75  may not be provided on the inner surface of the translucent cover  26 , and a diffusion surface to diffuse light may be provided. 
     Next, as shown in  FIG. 6 , the equipment device  12  includes an equipment reflector  81  expanded and opened downward, an equipment thermal radiator  82  as an equipment body attached to an upper part of the equipment reflector  81 , a socket  83  attached to a lower part of the equipment thermal radiator  82 , a terminal base  85  attached to an upper part of the equipment thermal radiator  82  by an attachment plate  84 , and a plurality of attachment springs for ceiling attachment attached to the periphery of the equipment thermal radiator  82 . 
     The equipment reflector  81  is formed into a cylindrical shape expanding downward. 
     The equipment thermal radiator  82  is made of a material, for example, metal such as aluminum die cast, ceramic, or resin having excellent thermal radiation properties. The equipment thermal radiator  82  includes a disk-shaped base part  87 , and a plurality of thermal radiation fins  88  protruding from an upper surface of the base part  87 . A flat contact surface  89  exposed in the equipment reflector  81  is formed on a lower surface of the base part  87 . 
     The socket  83  includes a socket body  91  formed into an annular shape from an insulating synthetic resin, and a not-shown pair of terminals for power supply arranged in the socket body  91 . Incidentally, when dimming is supported, a plurality of terminals for dimming is also provided. 
     A circular insertion hole  92  through which the cap part  50  (protrusion  33 ) of the lamp device  11  is inserted is formed at the center of the socket body  91 . A plurality of connection holes through which the lamp pins  73  of the lamp device  11  are inserted is formed into a long hole shape along the circumferential direction on a lower surface of the socket body  91 . Terminals are arranged on upper sides of the respective connection holes, and the lamp pins  73  of the lamp device  11  inserted in the connection holes are electrically connected to the terminals. 
     A plurality of keys is protrudingly formed on the inner peripheral surface of the socket body  91 , and a plurality of substantially L-shaped key grooves is formed. The keys and the key grooves of the socket  83  and the key grooves  44  and the keys  45  of the lamp device  11  are respectively provided at corresponding positions. The keys  45  and the key grooves  44  of the lamp device  11  are matched with the key grooves and the keys of the socket  83 , the cap part  50  of the lamp device  11  is inserted in the socket  83 , and the lamp device  11  is rotated, so that the lamp device  11  can be detachably and attachably mounted on the socket  83 . 
     The socket  83  is supported to the equipment thermal radiator  82  by a support mechanism. In the support mechanism, the cap part  50  of the lamp device  11  is mounted on the socket  83 , so that the upper surface of the cap part  50 , that is, the external thermal radiation part  39  of the thermal radiator  21  is pressed to the contact surface  89  of the equipment thermal radiator  82  and the thermal conductivity is improved. 
     The attachment base  85  is electrically connected to the terminal of the socket  83 . 
     In the luminaire  10  including the lamp device  11  and the equipment device  12  as stated above, in order to mount the lamp device  11  on the equipment device  12 , the keys  45  and the key grooves  44  of the cap part  50  are matched with the key grooves and the key of the socket  83 , the cap part  50  is inserted in the socket  83 , and the lamp device  11  is rotated by a specified angle with respect to the socket  83 . As a result, the keys  45  of the cap part  50  are locked by the key grooves of the socket  83 , and the lamp device  11  can be attached to the socket  83 . By this, the lamp pins  73  of the cap part  50  are electrically connected to the respective terminals of the socket  83 . Besides, the upper surface of the cap part  50 , that is, the external thermal radiation part  39  of the thermal radiator  21  is pressed to and in close contact with the contact surface  89  of the equipment thermal radiator  82  through the thermal conductive sheet  46 , and heat can be efficiently conducted from the thermal radiator  21  to the equipment thermal radiator  82 . 
     At the time of lighting of the lamp device  11 , commercial AC power is supplied to the lighting device  25  of the lamp device  11 . The lighting device  25  converts the commercial AC power into specified DC power and supplies the power to the light-emitting elements  57  of the light-emitting module  23 , so that the light-emitting elements  57  are lit. The light of the lit light-emitting elements  57  passes through the translucent cover  26  and is irradiated to a specified irradiation direction. 
     In the lamp device  11 , since the light-emitting module  23  is arranged at the position close to the translucent cover  26  by the thermal radiator  21 , most of the light of the light-emitting elements  57  is directly incident on the translucent cover  26  and is emitted, so that the light extraction efficiency can be improved. 
     Besides, at the time of lighting of the lamp device  11 , heat generated by the light-emitting elements  57  of the light-emitting module  23  is mainly conducted from the board  58  to the light-emitting module connection part  38  of the thermal radiator  21 , the support part  37  and the external thermal radiation part  39  through the insulating sheet  60 . Further, the heat is conducted from the external thermal radiation part  39  to the equipment thermal radiator  82  through the heat conductive sheet  46 , and is radiated to the air from the plurality of thermal radiation fins  88  of the equipment thermal radiator  82 . 
     At this time, since the light-emitting module connection part  38  protrudes from the attachment surface  22   a  of the attachment base  22  to which the light-emitting module  23  is attached, the board  58  of the light-emitting module  23  certainly contacts the light-emitting module connection part  38 , and the heat generated by the light-emitting elements  57  is efficiently conducted from the board  58  to the light-emitting module connection part  38 . 
     Further, since the support part  37  of the thermal radiator  21 , the light-emitting module connection part  38  and the external thermal radiation part  39  are integrally formed, the heat generated by the light-emitting elements  57  is efficiently conducted from the light-emitting module connection part  38  of the thermal radiator  21  to the external thermal radiation part  39 . 
     In general, heat has a characteristic of being radially conducted. Since the sectional area of the support part  37  is increased from the light-emitting module connection part  38  toward the external thermal radiation part  39 , heat conduction loss at the support part  37  can be reduced. Thus, the heat generated by the light-emitting elements  57  of the light-emitting module  23  can be efficiently conducted from the light-emitting module connection part  38  to the external thermal radiation part  39 . 
     Accordingly, the heat generated by the light-emitting elements  57  can be efficiently conducted to the thermal radiator  21 , and the thermal radiation properties from the external thermal radiation part  39  of the thermal radiator  21  can be improved. 
     Besides, at the time of lighting of the lamp device  11 , the heat generated by the lamp device  25  is conducted to the housing  20  and the like, and is radiated to the air from the surface of the housing  20  and the like. 
     In the lamp device  11  of this embodiment, since the insulating attachment base  22  is arranged around the light-emitting module connection part  38  of the thermal radiator  21 , the peripheral part of the light-emitting module  23  connected to the light-emitting module connection part  38  can be stably supported, and insulation properties against the lighting device  25  can be secured. Further, since the light-emitting module connection part  38  protrudes from the attachment surface  22   a  of the attachment base  22 , the light-emitting module  23  certainly contacts the light-emitting module connection part  38 , and excellent thermal radiation properties can be secured. 
     Further, since the attachment base  22  is formed of insulating material, the attachment base  22  and the circuit parts  71  of the lighting device  25  can be arranged to be close to each other, and the lamp device  11  can be miniaturized. 
     Besides, the insulating sheet  60  intervenes between the light-emitting module connection part  38  and the light-emitting module  23  and between the attachment base  22  and the light-emitting module  23 . Thus, the step difference between the light-emitting module connection part  38  and the attachment base  22  is absorbed by the difference in compression amount of the insulating sheet  60 , and the application of stress to the light-emitting module  23  can be relieved. 
     Besides, since the reflector  24  is arranged between the opening part  29  of the housing  20  and the light-emitting module  23 , the reflector  24  reflects the light of the light-emitting elements  57  to the irradiation direction, and the light extraction efficiency can be improved. Further, since the reflector  24  covers the lighting device  25 , the light of the light-emitting elements  57  can be prevented from being irradiated to the circuit board  70  of the lighting device  25  and the circuit parts  71 , and light deterioration of the circuit board  70  and the circuit parts  71  can be prevented. Further, the board  58  can be held between the reflector  24  and the attachment base  22 . Accordingly, the reflector  24  has the three functions, that is, the reflection function, the protection function of the lighting device  25  and the fixing function of the light-emitting module  23 . 
     Incidentally, since the attachment base  22  is made of the insulating material having excellent heat conductivity, the heat generated by the light-emitting elements  57  can be efficiently conducted from the board  58  to the thermal radiator  21  through the attachment base  22 , and the thermal radiation properties can be improved. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.