1. Field of the Invention
The present invention relates to a vehicular lamp. More specifically, the present invention relates to a vehicular lamp that includes a power supply member that supplies power from a power source to a semiconductor light emitting element that is a light source, and a housing portion that accommodates the power supply member.
2. Related Art
Semiconductor light emitting elements typified by light emitting diodes are increasingly used as light sources of automotive lamps (vehicular lamps) because they emit light with an extremely small current, and therefore, have a longer life and less power consumption compared to filament bulbs. A vehicular tail lamp is known that uses a semiconductor light emitting element as a light source (see Patent Document 1, for example). Semiconductor light emitting elements are also being used as light sources for headlamps, in addition to interior lamps, stop lamps, and the like, because higher intensity types of semiconductor light emitting elements have been developed in recent years.
When a semiconductor light emitting element is used as a light source, a heat sink or the like for heat dissipation, for example, must be provided in order to efficiently dissipate heat generated from the element and a control circuit that controls the current supplied to the element. In this case, if a solder or a screw is used to secure the heat sink and the semiconductor light emitting element, the entire heat sink must also be replaced when the element is replaced.
In one or more embodiments, the present invention provides a vehicular lamp having a semiconductor light emitting element as a light source, the vehicular lamp characterized by including: a heat dissipation member that dissipates heat generated by the semiconductor light emitting element when lit; a power supply member that supplies power from a power source to the semiconductor light emitting element; a light emitting element holding portion that holds the semiconductor light emitting element in a state of contact with the heat dissipation member, and electrically connects the semiconductor light emitting element and the power supply member; and a housing portion that is secured to a lamp body, and accommodates the power supply member and the heat dissipation member, wherein the light emitting element holding portion is detachably secured to the heat dissipation member.
According to the vehicular lamp described above, the semiconductor light emitting element can be easily replaced by attaching and detaching the light emitting element holding portion. Further, the semiconductor light emitting element is in contact with the heat dissipation member due to the light emitting element holding portion. Therefore, heat from the semiconductor light emitting element can be efficiently dissipated.
In the vehicular lamp described above, the heat dissipation member is preferably formed of a metal material, and the light emitting element holding portion preferably puts a surface, having an electrical insulation property, of the semiconductor light emitting element in contact with the heat dissipation member.
Such planar contact of the heat dissipation member and the semiconductor light emitting element enables heat from the semiconductor light emitting element to be efficiently dissipated. In addition, even if the heat dissipation member is formed of an inexpensive metal material having good heat conductivity, it is possible to prevent the heat dissipation member from contacting and short circuiting an electrode of the semiconductor light emitting element or the like.
In the vehicular lamp described above, the semiconductor light emitting element and the power supply member are preferably provided on opposite sides of the heat dissipation member in a lamp longitudinal direction with the heat dissipation member interposed therebetween.
Consequently, compared to providing the semiconductor light emitting element and the power supply member on the same side of the heat dissipation member, it is easier to secure a space for contacting the semiconductor light emitting element to the heat dissipation member.
In the vehicular lamp described above, it is preferable that the light emitting element holding portion detachably holds the power supply member.
Thus, the power supply member can be secured to the heat dissipation member by the light emitting element holding portion. Therefore, it is not necessary to provide a structure on the power supply member for securing the power supply member to the heat dissipation member.
Other aspects and advantages of the invention will be apparent from the following description, the drawings and the claims.
Hereinafter, the present invention will be described with reference to the figures. All of the features and the combinations thereof described in the embodiments set forth below are not necessarily essential and one or more aspects of the invention may be included in one or more embodiments.
Note that in the description herein “forward of the lamp” refers to a direction of illumination by the vehicular lamp 10, and is an upward direction in
As shown in
The light emitting element 100 is an example of a semiconductor light emitting element in accordance with one or more embodiments of the present invention. The light emitting element 100 has a package portion 110 on which a plurality (three in the present example) of LED chips 121, which are electrically connected by a lead frame and bonding wires (not shown in the drawings), is sealed by a transparent resin material in a general parallelepiped configuration. Note that a resin having an electrical insulation property may also be used for the above sealing.
A portion of the lead frame is exposed as electrodes 111, 112 on both sides of one surface of the package portion 110. The electrodes 111, 112 are connecting terminals that connect to the LED chip 121 and a power source (not shown in the drawings). Specifically, one of the electrodes 111, 112 is a positive terminal of the light emitting element 100, and the other is a ground terminal of the light emitting element 100.
In the light emitting element 100 of the present example, a surface provided with the electrodes 111, 112 is a light emitting surface. Specifically, the light emitting element 100 emits light between the electrode 111 and the electrode 112 from the surface provided with the electrodes 111, 112, and has an optical axis in a direction perpendicular to the light emitting surface.
The heat dissipation member 200 is a member provided in order to efficiently release heat generated by the light emitting element 100 in particular to outside when the light emitting element 100 is lit. The heat dissipation member 200 is formed of a metal material with excellent heat conductivity, such as aluminum, for example. As shown in
In addition, the planar portion 210 is provided with through holes 231, 232, 233, 234 along four sides thereof. Among the four through holes 231 to 234, opposing through holes respectively have the same hole shape. Specifically, the through hole 231 and the through hole 232 have the same hole shape, and the through hole 233 and the through hole 234 have the same hole shape.
The heat dissipation member 200 is arranged more toward a lamp rearward side than the light emitting element holding portion 300 and the light emitting element 100 when assembled as the vehicular lamp 10. As shown in
Note that, as described above, conductive portions of the LED chip 121, the lead frame, and the like of the light emitting element 100 are sealed inside the package portion 110 except for the electrodes 111, 112 that are exposed to the lamp forward side. Therefore, even if the heat dissipation member 200 and a surface on the opposite side of the light emitting surface of the light emitting element 100 are in planar contact, the conductive portions of the light emitting element 100 do not contact the heat dissipation member 200 and short circuit.
The light emitting element holding portion 300 has a holding portion body 305 with a general parallelepiped configuration, and a pair of engagement projections 321, 322 that extend from the holding portion body 305 parallel to side surfaces of the holding portion body 305. The holding portion body 305 and the engagement projections 321, 322 are formed of a resin material having an electrical insulation property in the present example.
In addition, the holding portion body 305 is provided with a generally oblong opening portion 310 that penetrates from an upper surface to a lower surface. The engagement projections 321, 322 extend from the holding portion body 305 along a pair of opposing side surfaces on the holding portion body 305, and distal end portions thereof are provided with engagement tabs 323, 324 that project inward.
The light emitting element holding portion 300 further has electrodes 311, 312 that project toward an inner side of the opening portion 310, and a pair of electrodes 315, 316 that extend from the holding portion body 305 parallel to side surfaces of the holding portion body 305. The electrodes 315, 316 are covered by covering portions 317, 318 that extend a predetermined length from the holding portion body 305. The covering portions 317, 318 are formed of a material having an electrical insulation property.
As shown in
The power supply member 400 has a circuit board 410 that is provided with a pair of through holes 431, 432 that penetrate from an upper surface to a lower surface, connectors 421, 422 that are secured on the upper surface of the circuit board 410, and electrodes 441, 442, 443 that are secured on the lower surface of the circuit board 410. The circuit board 410 is provided in order to supply power from the power source to the light emitting element 100 and to control a current value thereof. The circuit board 410 may be a bus bar circuit board or a printed circuit board, for example. Note that a rectifier diode, a current control resistance, and the like are arranged on the circuit board 410, but are not shown in the drawings.
As shown in
The flexible electrode 423 of the connector 421 is electrically connected to an end of a conductive securing pin 425 that penetrates the outer frame of the connector 421. As shown in
The electrodes 441 to 443 vertically project from the lower surface of the circuit board 410. In the present example, the electrodes 441 to 443 are elongated metal plates with generally oblong cross sections, and are secured by solder to the circuit board 410. The electrodes 441 to 443 are supported by a support portion 440 that is secured to the circuit board 410.
The housing portion 500 is formed from an upper housing portion 502 and the lower housing portion 501. As shown in
The side wall 511 extends from an outer edge of the generally disc-shaped bottom wall 512 perpendicular to the bottom wall 512. The heat dissipation member securing portions 531, 532 also extend from the bottom wall 512 in the same direction as the side wall 511. In the present example, the heat dissipation member securing portions 531, 532 are generally shaped as cylinders and respectively provided with screw holes 541, 542. The connector 520 extends from a center portion of the bottom wall 512 toward a side opposite the extension direction of the side wall 511. The center portion of the bottom wall 512 is provided with a plurality (three in the present example) of through holes 521 that penetrate the bottom wall 512. The through holes 521 are provided to be inserted with the electrodes 441, 442, 443 of the power supply member 400 and allow their projection toward the connector 520 side.
As shown in
The upper housing portion 502 has a concave surface portion 562 that is provided with an opening 561 at its center, and a generally cylindrical side wall 563 that vertically extends from the concave surface portion 562. The concave surface portion 562 is formed with a surface that convexly curves in an extending direction of the side wall 563 on a side opposite the side from which the side wall 563 extends. A substance with high reflectivity such as aluminum is vapor-deposited on the curved surface.
The side wall 563 of the upper housing portion 502 is provided with a fitting projection 564 at regular intervals in the circumferential direction (three locations at 120-degree intervals in the present example). In addition, the side wall 511 of the lower housing portion 501 is provided with a fitting hole 514 at regular intervals in the circumferential direction (three locations at 120-degree intervals in the present example).
Components forming the vehicular lamp 10 were described above. These components are arranged, from the lamp forward side, in the order of the upper housing portion 502, the light emitting element holding portion 300, the light emitting element 100, the heat dissipation member 200, the power supply member 400, and the lower housing portion 501.
When assembled as the vehicular lamp 10, the light emitting element 100 is supported by the light emitting element holding portion 300 with a surface on the opposite side of the light emitting surface on the package portion 110 in a state of contact with the planar portion 210 of the heat dissipation member 200.
Specifically, as shown in
Distal end portions of the electrodes 315, 316 passed through the through holes 231, 232 are subsequently inserted into the connectors 421, 422 of the power supply member 400, which is arranged on the side opposite the heat dissipation member 200. At such time, in the connector 421 for example, the flexible electrode 423 deforms while deflecting to both sides and contacts the inserted electrode 315 from both sides. Although not shown in the drawings, a flexible electrode in an inner portion of the connector 422 contacts the electrode 316 from both sides, similar to the connector 421.
At such time, the engagement projections 321, 322 of the light emitting element holding portion 300 pass through the through holes 233, 234 of the heat dissipation member 200 and the through holes 431, 432 of the power supply member 400. As shown in
Accordingly, the light emitting element 100 is accommodated in the opening portion 310 of the light emitting element holding portion 300, and the electrodes 111, 112 of the light emitting element 100 contact the electrodes 311, 312 of the light emitting element holding portion 300. Therefore, the light emitting element 100 is held in a lamp longitudinal direction by the planar portion 210 of the heat dissipation member 200 and the electrodes 311, 312 of the light emitting element holding portion 300, and held in a lamp sideward direction by the holding portion body 305 of the light emitting element holding portion 300.
Note that, in the present example, the light emitting element holding portion 300 is secured to the heat dissipation member 200 by the engagement tabs 323, 324 on the distal ends of the engagement projections 321, 322 catching on the circuit board 410 with the heat dissipation member 200 interposed therebetween. Therefore, the light emitting element 100 and the power supply member 400 can be removed again from the heat dissipation member 200 by detaching the engagement tabs 323, 324 from the circuit board 410.
In addition, as shown in
Thus, in the vehicular lamp 10 of the present example, the light emitting element holding portion 300 detachably holds the light emitting element 100 and the power supply member 400. Accordingly, the light emitting element 100 and the power supply member 400 can be easily replaced, and the light emitting element 100 and the power supply member 400 can be held using one component. Therefore, the structure for attaching the power supply member 400 to the heat dissipation member 200, and the like, can be simplified.
The heat dissipation member 200 to which the light emitting element 100, the light emitting element holding portion 300, and the power supply member 400 are secured is attached to the lower housing portion 501 with the surface of the planar portion 210 on which the light emitting element 100 is arranged on an upper side. In the present example, as shown in
Next, the upper housing portion 502 is fitted to the lower housing portion 501 such that an outer surface of the side wall 563 of the upper housing portion 502 and an inner surface of the side wall 511 of the lower housing portion 501 slide against each another. Here, the upper housing portion 502 and the lower housing portion 501 are secured to one another by fitting the fitting projection 546 of the upper housing portion 502 into the fitting hole 514 of the lower housing portion 501.
In the vehicular lamp 10 assembled as described above, as shown in
The light source attachment portion 610 is a generally cylindrical member provided at the center of the lamp body 600, and an end thereof is connected to an opening 320 provided in the lamp body 600. An inner circumferential diameter of the light source attachment portion 610 is generally equivalent to an outer circumferential diameter of the lower housing portion 501 of the vehicular lamp 10. The light source attachment portion 610 is also formed with an engagement groove 611 at regular intervals in the circumferential direction (three locations at 120-degree intervals in the present example).
When attaching the vehicular lamp 10 to the lamp body 600, first, the engagement projection 515 on the vehicular lamp 10 side is inserted into the engagement groove 611 of the light source attachment portion 610. By rotating the vehicular lamp 10 such that the engagement projection 515 is guided by the engagement groove 611, the engagement projection 515 fits into an engagement recess portion 612 formed on an end of the engagement groove 611. Thus, the vehicular lamp 10 is secured to the lamp body 600.
While description has been made in connection with exemplary embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modification may be made therein without departing from the present invention. It is aimed, therefore, to cover in the appended claims all such changes and modifications falling within the true spirit and scope of the present invention.
Number | Date | Country | Kind |
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2009-206150 | Sep 2009 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
7290913 | Watanabe et al. | Nov 2007 | B2 |
20090207617 | Merchant et al. | Aug 2009 | A1 |
20100067251 | Tokunaga | Mar 2010 | A1 |
20110128754 | Aiso et al. | Jun 2011 | A1 |
20110188204 | Horiuchi et al. | Aug 2011 | A1 |
Number | Date | Country |
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2008-084578 | Apr 2008 | JP |
Entry |
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English abstract of Japanese Publication No. 2008084578 published on Apr. 10, 2008, 1 page. |
Number | Date | Country | |
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20110058387 A1 | Mar 2011 | US |