JP2013012347A - Heat radiation mechanism, and light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a heat radiation member for radiating heat of a light source and a heat radiation member for radiating heat of a control circuit to control lighting of the light source, by effectively utilizing a space.SOLUTION: A first heat sink 32 radiates heat of a light-emitting element 20 constituted of an LED in an attachment unit 33. A second heat sink 62 radiates heat of a control circuit substrate 42 for controlling lighting of the light-emitting element 20 and is arranged to overlap with the first heat sink 32 when viewed from a direction parallel to the control circuit substrate 42. The first heat sink 32 is installed to overlap with the vicinity of both end parts of the control circuit substrate 42 when viewed from a direction vertical to the control circuit substrate 42. The attachment has a lower heat conductance than the first heat sink 32 and the second heat sink 62. The first heat sink 32 and the second heat sink 62 are mutually fixed through the attachment.

Description

  The present invention relates to a heat dissipation mechanism and a light emitting device, and more particularly, to a heat dissipation mechanism that dissipates heat from a light source and a control circuit board that controls lighting of the light source, and a light emitting device including the heat dissipation mechanism.

  2. Description of the Related Art There is a known technology that uses a semiconductor light emitting element such as an LED (Light Emitting Diode) as a light source for a vehicle headlamp. Here, a light source device is proposed in which at least one of the electrical connection means between the light emitting element and the circuit board is provided so as to pass through the irradiation direction when viewed from the light emitting element (for example, see Patent Document 1). ).

JP 2005-32661 A

  For example, in a vehicle headlamp, a control circuit that controls lighting of a light emitting element may be provided separately from a mounting substrate on which the light emitting element is directly mounted. Since this control circuit also generates heat, it may be necessary to dissipate heat. Light emitting elements such as LEDs also need to dissipate heat. However, for example, if the heat dissipating member of the control circuit and the heat dissipating member of the light emitting element are arranged at completely different locations, it is difficult to suppress the occupied space by these heat dissipating members. For this reason, suppression of the occupation space by these heat radiating members has become an important issue in miniaturization of vehicle headlamps.

  Then, this invention was made | formed in order to solve the subject mentioned above, The objective is to dissipate the heat of the light source and the heat dissipation member to dissipate the heat of the control circuit that controls the lighting of the light source. It is to arrange using space effectively.

  In order to solve the above problems, a heat dissipation mechanism according to an aspect of the present invention dissipates heat from a first heat dissipation member that dissipates heat from a light source and a control circuit board that controls lighting of the light source, and is parallel to the control circuit board. A second heat dissipating member disposed so as to at least partially overlap the first heat dissipating member as viewed from the first direction. The first heat radiating member is provided so as to overlap a part of the control circuit board when viewed from the second direction perpendicular to the control circuit board.

  According to this aspect, first, the first radiating member and the second radiating member are arranged so that the first radiating member and the second radiating member are overlapped when viewed from the first direction, so that the first space occupied by the first and second radiating members is first. The area viewed from the direction can be suppressed. Next, since the first heat radiating member is provided so as to overlap a part of the control circuit board when viewed from the second direction, the first heat radiating member overlaps with the control circuit board while forming the first heat radiating member large. And the area of the occupied space viewed from the second direction due to the second heat radiating member can be suppressed.

  You may further provide the heat-separation member whose heat conductivity is lower than a 1st heat radiating member and a 2nd heat radiating member. The first heat radiating member and the second heat radiating member may be fixed to each other via a heat separating member. According to this aspect, it is possible to suppress heat transfer between the first heat radiating member and the second heat radiating member. For this reason, the influence by the heat which one side among a light source and a control circuit part gives to the other can be suppressed. In order to further suppress the influence of this heat, the heat separating member may have a slit formed so as to reduce the contact area between the first heat radiating member and the second heat radiating member.

  The second heat radiating member is formed such that a portion facing the substantially center of the control circuit board protrudes in the second direction from a portion facing the vicinity of a predetermined end of the control circuit board. It may be provided so as to overlap with the vicinity of a predetermined end of the control circuit board when viewed from the direction.

  Such a control circuit board is generally easy to collect mounting components that generate heat at a central portion. Therefore, according to this aspect, the space near the end of the substrate can be used for the first heat radiating member while efficiently dissipating the heat of the substrate. For this reason, the occupation space by a 1st heat radiating member and a 2nd heat radiating member can be suppressed, avoiding the fall of the heat dissipation of a board | substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the heat radiating member which dissipates the heat of a light source, and the heat radiating member which dissipates the heat of the control circuit which controls lighting of a light source can be arrange | positioned using space effectively.

It is a figure which shows the structure of the vehicle headlamp which concerns on this embodiment. (A) is a perspective view which shows the structure of the light emitting module which concerns on this embodiment, (b) is a side view of the light emitting module which concerns on this embodiment. It is a perspective view which shows the assembly method of the light emitting module which concerns on this embodiment. It is a perspective view of the attachment unit concerning this embodiment. (A) is a top view of the circuit unit, (b) is a right side view of the circuit unit, and (c) is a front view of the circuit unit. It is a top view of an attachment. (A) is a top view of the attachment unit, (b) is a right side view of the attachment unit, and (c) is a back view of the attachment unit. (A) is PP sectional drawing of Fig.7 (a), (b) is QQ sectional drawing of Fig.7 (a). In the top view of an attachment unit, it is the figure showing the area | region in which the heat sink fin of the 1st heat sink was provided, and the area | region in which the heat sink fin of the 2nd heat sink was provided.

  Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a vehicle headlamp 10 according to the present embodiment. FIG. 1 shows a cross-sectional view of a vehicle headlamp 10 along a vertical plane including a lamp optical axis Ax1. The vehicle headlamp 10 functions as a low beam light source that forms a so-called low beam light distribution pattern. Of course, the vehicular headlamp 10 is not limited to this, and the vehicular headlamp 10 may function as a high beam light source that forms a high beam light distribution pattern.

  The vehicle headlamp 10 includes a projection lens 12, a light emitting module 14, a reflector 16, and a shade 18. The projection lens 12 is a plano-convex aspheric lens having a convex front surface and a flat rear surface, and projects a light source image formed on the rear focal plane in front of the lamp as a reverse image.

  The light emitting module 14 functions as a light emitting device, and includes a light emitting element 20 configured by an LED that is a semiconductor light emitting element. In addition, the light emitting element 20 may be comprised by light emitting elements other than LED, and it replaces with the light emitting element 20, and other light sources, such as a discharge lamp and an incandescent lamp, may be used. The light emitting module 14 is disposed so that the light emitting element 20 mainly emits light upward.

  The reflector 16 has a reflecting surface 16a that reflects and collects light emitted from the light emitting element 20. The reflector 16 is disposed above the light emitting element 20 so that the reflecting surface 16 a faces the light emitting element 20. The shade 18 includes a shade portion 18a and a connecting portion 18b. The shade portion 18a has a plane including the lamp optical axis Ax1 and forms a cut-off line near the horizontal line of the low beam light distribution pattern. In addition, since the shape of the shade part 18a is well-known, description is abbreviate | omitted. The connecting part 18b connects the projection lens 12 and the shade part 18a. In addition, the connection part 18b functions also as a design member which comprises the design surface which can be recognized from the outside.

  FIG. 2A is a perspective view illustrating a configuration of the light emitting module 14 according to the present embodiment, and FIG. 2B is a side view of the light emitting module 14 according to the present embodiment. The light emitting module 14 includes a package 30, a first heat sink 32, an attachment 34, a fan 36, a cover 40, and a control circuit board 42.

  The package 30 includes the light emitting element 20. The control circuit board 42 controls lighting of the light emitting element 20. In the present embodiment, the control circuit board 42 includes a printed wiring board and electric components and elements mounted on the printed wiring board.

  The first heat sink 32 is made of a heat radiating material having a high heat radiating property such as aluminum, and functions as a heat radiating member. The first heat sink 32 has heat radiating fins 32 a and dissipates heat generated by the light emitting element 20. The first heat sink 32 is attached to the lower surface 34 e of the attachment 34. Therefore, the lower surface 34e of the attachment 34 functions as a heat radiating member mounting portion.

  The radiation fins 32 a of the first heat sink 32 are provided below the first heat sink 32. The radiation fin 32a is provided so as to extend in a direction perpendicular to the lamp optical axis Ax1. The fan 36 is attached to the first heat sink 32 below the radiation fin 32a so that air can be blown onto the radiation fin 32a.

  A fixed connector 38 is integrally fixed to the attachment 34 by integral molding with resin. The fixed connector 38 is provided so that a wire connector can be coupled thereto. Further, the attachment 34 is provided with a circuit accommodating portion that is recessed downward to accommodate the control circuit board 42. The control circuit board 42 is accommodated in this circuit accommodating portion. After the control circuit board 42 is accommodated, the cover 40 is attached to the attachment 34. Note that the cover 40 may be deleted. Further, instead of the cover 40, after the control circuit board 42 is accommodated in the circuit accommodating portion, resin may be molded in the circuit accommodating portion.

  The length of the control circuit board 42 in the direction perpendicular to the lamp optical axis Ax1 is longer than the length in the direction parallel to the lamp optical axis Ax1. Specifically, the length in the direction perpendicular to the lamp optical axis Ax1 is at least twice as long as the length in the direction parallel to the lamp optical axis Ax1. By providing the control circuit board 42 in this way, the length of the light emitting module 14 in the lamp optical axis Ax1 direction can be suppressed, and the vehicle headlamp 10 can be further downsized.

  An attachment unit 33 is configured by the attachment 34, the control circuit board 42, and the cover 40. In the present embodiment, before the attachment 34 is attached to the first heat sink 32, the control circuit board 42 and the cover 40 are attached in advance to the attachment 34, and are attached to the first heat sink 32 as the attachment unit 33. As a result, the attachment 34 and the control circuit board 42 are integrally attached to the first heat sink 32, and at the same time, the package 30 is sandwiched and attached between the first heat sink 32. Therefore, the attachment 34 functions as a light source fixing member that fixes the light emitting element 20 as a light source to the first heat sink 32.

  As described above, the light emitting module 14 is configured integrally with the light emitting element 20 that is a light source and the control circuit board 42 that controls the lighting of the light emitting element 20. Thus, by incorporating the light emitting module 14 into the vehicle headlamp 10, the light emitting element 20 and the control circuit board 42 can be attached to the vehicle headlamp 10 at the same time. For this reason, the assembly man-hour of the vehicle headlamp 10 can be reduced.

  The package 30 includes a light emitting element 20, a submount substrate 50, and a mounting substrate 52. The light emitting element 20 is mounted on the submount substrate 50, and the submount substrate 50 is mounted on the mounting substrate 52. The mounting substrate 52 is provided with a conductive member (not shown) for supplying power.

  The control circuit board 42 is disposed in front of the lamp with respect to the light emitting element 20. At this time, the control circuit board 42 is disposed in front of the lamp rather than the light emitting element 20 so as to avoid the light path used for forming the light distribution pattern among the light emitted from the light emitting element 20. Specifically, the control circuit board 42 is disposed in front of the lamp and below the cover 40 with respect to the package 30. Since the light path used for forming the light distribution pattern is further above the shade portion 18a of the shade 18 disposed on the cover 40, the control circuit board 42 is disposed below the cover 40. The control circuit board 42 can be arranged in a region avoiding the light path used for forming the pattern.

  The light emitting module 14 is disposed so that the main optical axis Ax2 of the light emitting element 20 is directed vertically upward. The main optical axis Ax2 is an axis perpendicular to the main light emitting surface that passes through the center of the main light emitting surface that is the upper surface of the light emitting element 20. Therefore, the light emitting module 14 is disposed so that the lamp optical axis Ax1 of the vehicle headlamp 10 and the main optical axis Ax2 of the light emitting element 20 are orthogonal to each other. Thereby, the reflector 16 can be efficiently irradiated with light. For this reason, the low beam light distribution pattern can be more appropriately formed through the reflector 16.

  The light emitting element 20 is arranged such that the light emitting portion protrudes in the direction of the main optical axis Ax2 from the control circuit board 42. The light emitting unit includes a main light emitting surface of the light emitting element 20 and a side surface surrounding the main light emitting surface. Thereby, it can avoid that the control circuit board 42 is located in front of the lamp of a light emission part, and the influence of the light distribution pattern by arrange | positioning the control circuit board 42 in front of a lamp can be avoided.

  The cover 40 is provided so as to cover the entire opening above the circuit housing portion in order to prevent foreign matter from entering the control circuit board 42. Therefore, the cover 40 is provided so as to cover the entire surface of the control circuit board 42. The cover 40 may be provided so as to cover a part of the control circuit board 42.

  When the wire connector 58 is coupled to the fixed connector 38, a coupling portion for coupling the wire connector 58 is provided below so that the wire connector 58 can be coupled by being moved vertically upward in an area where the light connector 58 has avoided the light path. Yes. Of course, the connecting direction of the wire connector 58 is not limited to this, and the wire connector 58 is provided in a region where the light path is avoided so that the wire connector 58 can be moved and connected in another direction approaching the light path. It may be.

  The wire connector 58 is configured such that a wire is taken out from the side opposite to the tip portion coupled to the fixed connector 38. For this reason, the wire connector 58 is moved vertically upward and coupled to the fixed connector 38, so that the wire coming out of the wire connector 58 can be positioned further away from the light path, and the wire is deformed. The possibility of affecting the light distribution pattern by advancing upward can be suppressed.

  FIG. 3 is a perspective view showing a method for assembling the light emitting module 14 according to the present embodiment. The attachment unit 33 further includes a second heat sink 62. The second heat sink 62 has a circuit mounting surface 62c, and a control circuit board 42 that controls lighting of the light emitting element 20 is attached to the circuit mounting surface 62c. The second heat sink 62 functions as a heat radiating member that dissipates heat from the control circuit board 42. Therefore, the first heat sink 32 and the second heat sink 62 function as a heat dissipation mechanism that dissipates heat of the light emitting element 20 and the control circuit board 42.

  First, the control circuit board 42 is attached to the second heat sink 62 to constitute the circuit unit 60. Next, the circuit unit 60 is fixed to the attachment 34. After the circuit unit 60 is fixed, the control circuit board 42 and the conductive member provided on the attachment 34 are connected by wire bonding or the like. Thereafter, a resin for sealing is filled on the circuit, and finally, a cover 40 is attached to the attachment 34 to constitute the attachment unit 33.

  FIG. 4 is a perspective view of the attachment unit 33 according to the present embodiment. The attachment unit 33 is configured by attaching the circuit unit 60 configured by placing the control circuit board 42 on the second heat sink 62 in this manner to the attachment 34.

  5A is a top view of the circuit unit 60, FIG. 5B is a right side view of the circuit unit 60, and FIG. 5C is a front view of the circuit unit 60. The second heat sink 62 includes a circuit support portion 62a and a heat radiating fin 62b. The circuit support portion 62a is formed in a plate shape having substantially the same size as the control circuit board 42. The control circuit board 42 is attached to the circuit mounting surface that is the upper surface.

  The radiating fins 62b are formed to extend downward from the lower surface of the circuit support portion 62a. The second heat sink 62 is formed such that a portion facing the substantially center of the control circuit board 42 protrudes below a portion facing the vicinity of both ends of the control circuit board 42. Specifically, the heat radiating fins 62 b of the second heat sink 62 are provided only in a portion facing substantially the center of the control circuit board 42.

  As shown in FIG. 5A, the main mounting components that generate heat are mounted in the center of the control circuit board 42. For this reason, the heat of the control circuit board 42 can be efficiently dissipated by using the heat radiation fins 62 b provided to face a part of the control circuit board 42.

  FIG. 6 is a top view of the attachment 34. The attachment 34 includes a circuit accommodating portion 34a, a fin insertion hole 34b, a slit 34c, an opening 34d, and a package fixing portion 34f.

  A control circuit board 42 that controls lighting of the light emitting element 20 is attached to the circuit housing portion 34a. Therefore, the circuit accommodating part 34a functions as a circuit attachment part. The circuit accommodating portion 34a is provided so as to be recessed downward, and the circuit unit 60 is fixed in contact with the bottom surface. The slit 34 c is formed at the bottom of the circuit housing portion 34 a so as to reduce the contact area between the first heat sink 32 and the second heat sink 62.

  The package fixing portion 34 f fixes the package 30 by sandwiching the package 30 with the first heat sink 32 by attaching the first heat sink 32 to the lower surface 34 e of the attachment 34. Thereby, the light emitting element 20 is fixed.

  The package fixing portion 34f is provided with an opening 34d, a conductive member 64, and a leaf spring 65. The opening 34d is formed so that the light emitting element 20 passes from below and protrudes from the upper surface of the attachment 34. The conductive member 64 is formed so as to protrude toward the inside of the opening 34d. When the first heat sink 32 is attached to the lower surface 34e of the attachment 34, the conductive member 64 contacts the electrode of the light emitting element 20 provided on the mounting substrate 52, and conducts the control circuit board 42 and the light emitting element 20 with each other. It is provided to let you. The leaf spring 65 presses and fixes the package 30 against the first heat sink 32 when the attachment 34 is attached to the first heat sink 32. Therefore, the leaf spring 65 functions as a pressing member that presses the package 30.

  The attachment 34 routes the conductive member 64 to the connection portion 66 to the control circuit board 42. Therefore, a portion of the attachment 34 between the package fixing portion 34 f and the connection portion 66 functions as a routing portion for routing the conductive member 64. The connecting portion 66 and the control circuit board 42 are connected by wire bonding or the like, and the conductive member 64 is connected to the control circuit board 42. The conductive member 64 is integrally formed with the attachment 34 except for a portion protruding from the opening 34 d and a portion exposed to the connection portion 66.

  The attachment 34 has a conductive member 68. The conductive member 68 is connected to a connection pin of the fixed connector 38. The conductive member 68 and the connection pin may be integrally formed. The conductive member 68 is also integrally formed with the attachment 34.

  After the control circuit board 42 is attached to the circuit housing part 34a, the control circuit board 42, the connection part 66, and the conductive member 68 are connected by wire bonding. As a result, the control circuit board 42 and the light emitting element 20 and the control circuit board 42 and the connection pins of the fixed connector 38 are electrically connected.

  7A is a top view of the attachment unit 33, FIG. 7B is a right side view of the attachment unit 33, and FIG. 7C is a back view of the attachment unit 33. In addition, illustration of the fan 36 is abbreviate | omitted in Fig.7 (a)-FIG.7 (c).

  As shown in FIGS. 7B and 7C, the radiation fins 32 a are provided below the first heat sink 32, and the radiation fins 62 b are provided below the second heat sink 62. As shown in FIG. 7C, the first heat sink 32 is provided with an opening 32 b for inserting the radiation fins 62 b of the second heat sink 62. The heat radiating fins 62b are inserted into the openings 32b.

  The heat radiation fins 32a of the first heat sink 32 and the heat radiation fins 62b of the second heat sink 62 are provided so as to extend in a direction perpendicular to the lamp optical axis Ax1. The fan 36 is attached to the first heat sink 32 below the heat radiation fins 32a and the heat radiation fins 62b so that air can be blown to the heat radiation fins 32a and the heat radiation fins 62b.

  In addition, the heat radiating fins 62 b of the second heat sink 62 are arranged so that each one extends in a straight line with the heat radiating fins 32 a of the first heat sink 32. Thereby, the space between the radiation fins 62b can be continued linearly to the space between the radiation fins 62b, and air can flow smoothly.

  8A is a cross-sectional view taken along the line P-P in FIG. 7A, and FIG. 8B is a cross-sectional view taken along the line Q-Q in FIG. In FIG. 8A, the heat radiation fins 32a of the first heat sink 32 are provided in front of and on the side of the heat radiation fins 62b of the second heat sink 62 illustrated. Accordingly, the radiation fins 62b of the second heat sink 62 are parallel to the control circuit board 42, such as a direction parallel to the lamp optical axis Ax1 shown in FIG. 8A or a direction perpendicular to the lamp optical axis Ax1 shown in FIG. When viewed from the right direction, the heat dissipating fins 32a of the first heat sink 32 are disposed so as to overlap. Thereby, when the first heat sink 32 and the second heat sink 62 are arranged so as not to overlap each other when viewed from the direction parallel to the control circuit board 42, that is, compared to the case where the first heat sink 32 and the second heat sink 62 are arranged at different positions above and below. The height can be suppressed. For this reason, the enlargement of the light emitting module 14 by providing both the 1st heat sink 32 and the 2nd heat sink 62 can be suppressed.

  The radiating fins 62b of the second heat sink 62 extend in a direction perpendicular to the control circuit board 42 to substantially the same position as the radiating fins 32a of the first heat sink 32. Thereby, compared with the case where both heights differ, the space of a height direction can be used effectively.

  As illustrated in FIG. 8A, the control circuit board 42 is attached to the circuit housing portion 34 a via a second heat sink 62 that dissipates heat of the control circuit board 42. At this time, the first heat sink 32 and the second heat sink 62 are fixed to each other via the attachment 34. Further, the second heat sink 62 is configured to be in non-contact with the first heat sink 32 when the first heat sink 32 is attached to the lower surface 34 e of the attachment 34.

  The circuit accommodating portion 34 a of the attachment 34 is formed of a material having a lower thermal conductivity than the first heat sink 32 and the second heat sink 62. For this reason, the attachment 34 is formed of a material having lower thermal conductivity than the first heat sink 32 and the second heat sink 62. Therefore, the attachment 34 functions as a heat separating member that separates the heat generated by the light emitting element 20 and the heat generated by the control circuit board 42 from each other. Thereby, by arranging the first heat sink 32 and the second heat sink 62 close to each other, it is possible to avoid the heat generated by one of the light emitting element 20 and the control circuit board 42 from being transmitted to the other.

  Further, the heat radiating fins 62b are provided so that a portion facing the substantially center of the control circuit board 42 extends downward when viewed in a direction parallel to the lamp optical axis Ax1. On the other hand, the heat radiating fins 62b are not provided in portions facing the vicinity of both ends of the control circuit board 42. It is generally easier to arrange a component that easily generates heat in the center of the control circuit board 42 than in the case where it is arranged near the end of the control circuit board 42. In this way, the heat dissipating fins 62b are provided so that the portions facing the substantially center of the control circuit board 42 extend downward, and further, components that are likely to generate heat in the control circuit board 42 are arranged in the center of the control circuit board 42. By doing so, the heat generated by the control circuit board 42 can be efficiently dissipated by the radiation fins 62b.

  The heat radiating fins 62b may be provided so that a portion facing a predetermined portion other than the approximate center of the control circuit board 42 extends downward when viewed in a predetermined direction parallel to the control circuit board 42. Good. Further, the heat radiating fins 62b are provided so that the portion of the control circuit board 42 facing the predetermined portion extends longer in the direction perpendicular to the control circuit board 42 than the portion of the control circuit board 42 facing the predetermined portion other than the predetermined portion. It may be done.

  As shown in FIG. 8B, the first heat sink 32 has a protrusion 32c. The protrusion 32 c is formed to protrude upward from the circuit mounting surface 62 c so that the light emitting element 20 protrudes vertically upward from the control circuit board 42. In the present embodiment, the cover 40 and the shade portion 18a are disposed above the control circuit board 42. Therefore, the protrusion 32c is formed to protrude upward from the circuit mounting surface 62c so that the light emitting portion of the light emitting element 20 is positioned above the upper surface of the shade portion 18a.

  FIG. 9 is a diagram illustrating a region where the heat radiation fins 32 a of the first heat sink 32 and a region where the heat radiation fins 62 b of the second heat sink 62 are provided in the top view of the attachment unit 33.

  As shown in FIG. 9, the radiation fins 32 a of the first heat sink 32 are provided so as to overlap the vicinity of both ends of the control circuit board 42 when viewed from the direction perpendicular to the control circuit board 42. As described above, the heat radiating fins 62 b are provided in the portion facing the substantially center of the control circuit board 42, but the heat radiating fins 62 b are not provided near both ends of the control circuit board 42. For this reason, the arrangement area of the radiation fin 32a can be expanded by providing the radiation fin 32a in this space.

  As described above, the light emitting element 20 needs to be cooled more than the control circuit board 42. On the other hand, since the area of the control circuit board 42 is generally large, if the radiation fins 62b having substantially the same area as that of the control circuit board 42 are provided at a height necessary for cooling the control circuit board 42, the light emitting element 20 is provided. The radiation fins 62b for cooling the control circuit board 42 can be lower than the radiation fins 32a for cooling. Even if the heat dissipating fins 32a and the openings 32b are arranged at the same position in the vertical direction with respect to the control circuit board 42, if the heights of the fins are different, the space generated by the difference in fin height is used effectively. Difficult to do.

  As described above, the heat radiating fins 62b for cooling the control circuit board 42 are provided only in a portion facing a part of the control circuit board 42, and the heat radiating fins 32a for cooling the light emitting element 20 are provided in addition to the control circuit board 42. By providing in the part facing this part, the fin of the area according to the necessity for cooling can be provided appropriately, suppressing the difference in height of both. Needless to say, the first heat sink 32 overlaps with the control circuit board 42 is not limited to the vicinity of the end of the control circuit board 42, and the first heat sink 32 is viewed from a direction perpendicular to the control circuit board 42. It may be provided so as to overlap with another part of the control circuit board 42.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 Vehicle headlamp, 14 Light emitting module, 16 Reflector, 16a Reflecting surface, 20 Light emitting element, 30 Package, 32 1st heat sink, 32a Heat radiation fin, 32b Opening part, 32c Projection part, 33 Attachment unit, 34 Attachment, 34a Circuit housing part, 34b Fin insertion hole, 34c slit, 34d opening, 34e bottom surface, 34f package fixing part, 36 fan, 38 fixing connector, 40 cover, 42 control circuit board, 54 conductive member, 60 circuit unit, 62 1st 2 heat sink, 62a circuit support part, 62b heat radiation fin, 62c circuit mounting surface, 64 conductive member, 68 conductive member.

Claims (5)

A first heat dissipation member that dissipates heat from the light source;
A second heat dissipating member that dissipates heat of the control circuit board that controls lighting of the light source, and is disposed so as to at least partially overlap the first heat dissipating member as viewed from a first direction parallel to the control circuit board;
With
The first heat radiating member is provided so as to overlap a part of the control circuit board when viewed from a second direction perpendicular to the control circuit board. A heat separating member having a lower thermal conductivity than the first heat dissipating member and the second heat dissipating member;
The heat dissipation mechanism according to claim 1, wherein the first heat dissipation member and the second heat dissipation member are fixed to each other via the heat separation member.   The heat dissipation mechanism according to claim 2, wherein the heat separation member includes a slit formed to reduce a contact area between the first heat dissipation member and the second heat dissipation member. The second heat dissipating member is formed such that a portion facing substantially the center of the control circuit board protrudes in a second direction from a portion facing the vicinity of a predetermined end of the control circuit board,
4. The heat dissipation mechanism according to claim 1, wherein the first heat dissipation member is provided so as to overlap with the vicinity of the predetermined end portion of the control circuit board as viewed in the second direction.   A light emitting device comprising the heat dissipation mechanism according to any one of claims 1 to 4.

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