JP2007012311A - Light emitting diode lamp unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact LED (light emitting diode) lamp unit having excellent heat dissipation property. <P>SOLUTION: The LED lamp unit includes an attaching member made of thermally conductive material; a base board arranged on the attaching member; an LED light source mounted on the base board; a lens which is arranged on the light emission side of the LED light source, and is positioned to the base board by partial close contact of the lens to the base board; and a case with a first engaging nail and a second engaging nail, which is fixed to the attaching member. The base board and the lens are held between the attaching member and the case, the first engaging nail fixes the case to the attaching member in relation with a direction of an axis which is vertical to the attaching member and a direction of a first axis which is horizontal with the attaching member, and the second engaging nail fixes the case to the attaching member in relation with the direction of the axis which is vertical to the attaching member and a direction of a second axis which is horizontal with the attaching member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LED lamp unit.

LED lamp units that take advantage of LEDs such as small size and power saving are being used in various applications. In the LED lamp unit, a substrate on which the LED lamp is mounted is covered with a frame, a cover, or the like and protected from the outside. For example, Patent Document 1 discloses an apparatus that protects a substrate on which a semiconductor is mounted by covering it with a frame and a cover. In such an apparatus, both the frame and the cover are formed of a thermoplastic resin, and a part of the contact point between the frame and the cover is softened (melted) with heat and joined (so-called heat caulking) to fix both. Have been.
On the other hand, in LED lamp units used for various purposes, the heat generation often becomes a problem. In such a case, heat dissipation characteristics are improved by using a heat sink or the like. For example, Patent Document 2 discloses an LED unit that efficiently releases heat of an LED by providing a heat sink on the back side of the substrate.

Japanese Patent Laid-Open No. 5-67691 JP 2003-178602 A

For example, a lamp device used for illuminating a specific area, such as a map lamp for a vehicle, requires light distribution control of an LED light source. A lens is usually used for light distribution control. In order to realize desired light distribution control, it is necessary to fix the lens at a predetermined position. For example, the lens can be fixed to the substrate by heat caulking in accordance with a conventional example, but the lens is deformed by heat and pressure at the time of heat caulking. If the lens is deformed, its optical characteristics are affected and the lens accuracy is lowered. Therefore, highly accurate light distribution control cannot be performed.
With the background of diversification of light emission modes of LED lamp units, it is required to perform light distribution control with higher accuracy. Light distribution control can be performed by a lens. As a method of fixing the lens to the LED lamp unit, a method of fixing by heat caulking similarly to the fixing of the frame and the cover can be considered. However, if a part of the lens or a leg formed integrally with the lens is fixed by heat caulking, sinking (distortion or deformation) occurs in the lens itself due to melting during heat caulking. If the lens is distorted or deformed, the lens accuracy of the lens is lowered, and high-precision light distribution control cannot be performed. In addition to the lens, it may be possible to use a special member separately for high accuracy of light distribution control, but the number of parts increases and the apparatus becomes complicated.
On the other hand, the use of a heat sink for improving heat dissipation involves an increase in manufacturing cost due to an increase in the number of parts and a complicated manufacturing process. Moreover, the problem that an apparatus enlarges also arises. If the size of the device increases, it is difficult to secure an installation space. For example, the device cannot be installed with a high degree of freedom in a limited space such as a vehicle interior. Furthermore, in view of the fact that the amount of heat generation is expected to increase with the increase in brightness of LEDs in the future, it is desired that the LED lamp unit has a structure with excellent heat dissipation characteristics.
In view of the above problems, an object of the present invention is to provide an LED lamp unit that realizes highly accurate light distribution control with a simple configuration. In particular, it is another object of the present invention to provide an LED lamp unit that realizes high light distribution control by incorporating a lens without disposing the lens without degrading the lens accuracy. Another object is to provide an LED lamp unit that is small in size and excellent in heat dissipation characteristics.

In order to achieve at least one of the above objects, the present invention provides the following LED lamp unit. That is, a mounting member made of a heat conductive material,
A substrate disposed on the mounting member;
An LED light source mounted on the substrate;
A lens disposed on the light emitting side of the LED light source, a part of which is positioned with respect to the substrate by contacting the substrate;
A first locking claw and a second locking claw, and a case fixed to the mounting member,
The substrate and the lens are sandwiched between the mounting member and the case, and the first locking claw fixes the case to the mounting member in a vertical axis direction and a first horizontal axis direction with respect to the mounting member, The second locking claw is an LED lamp unit that fixes the case to the mounting member in the vertical axis direction and the second horizontal axis direction with respect to the mounting member.

  In the present invention, since the substrate and the lens are sandwiched between the case and the mounting member, the substrate and the lens are fixed to the mounting member with a simple configuration without requiring a special configuration. That is, when the lens is fixed, the lens itself is not heat squeezed, so that the lens accuracy is not deteriorated due to deformation. Therefore, highly accurate light distribution control is possible. On the other hand, the positioning of the lens is not based on the case, but is performed based on the substrate on which the LED light source is mounted. Thereby, a positional shift and an error between the lens and the LED light source hardly occur, and high-precision light distribution control by the lens is realized. Moreover, in the structure of this invention, heat radiation is actively performed using the attachment member which consists of heat conductive materials. Thereby, it becomes an LED lamp unit excellent in heat dissipation characteristics with a simple and small configuration. Further, the case is fixed to the mounting member in three directions, ie, a vertical axis direction, a first horizontal axis direction, and a second horizontal axis direction with respect to the mounting member by the first locking claw and the second locking claw. As a result, the displacement and backlash of the case are reduced.

Hereinafter, the components of the LED lamp unit in the present invention will be described in detail.
(Mounting member)
The LED lamp unit is provided with a mounting member. The LED lamp unit can be mounted at a desired position by the mounting member. The mounting member is formed of a heat radiating material such as a metal having high thermal conductivity such as aluminum or copper, or a resin containing filler made of metal or ceramic. By forming the attachment member with a thermally conductive material, the heat of the LED light source described later can be efficiently radiated through the attachment member. That is, the attachment member can have a function as a heat sink.

(LED light source and substrate)
The type of the LED light source is not particularly limited, and a bullet-type LED lamp, a surface-mount LED lamp, or an LED chip can be directly used. Further, the number of LED light sources to be used is not limited, and one or a plurality of LED light sources can be used. When using a plurality of LED light sources, the types of LED light sources may be the same or different types of LED light sources may be included. The emission color of the LED light source is appropriately selected according to the purpose. For example, white, red, green, blue, etc. are selected according to the desired emission color. The light emission colors of the plurality of LED light sources used may be the same or may include LED light sources of different light emission colors.
An LED light source is mounted on the substrate. The material of the substrate is not particularly limited, but it is preferable to form the substrate with a material having high thermal conductivity such as a metal such as Al or Cu or a high thermal conductive resin. This is because the heat of the LED light source can be efficiently propagated to the mounting member or the like.
The substrate is disposed on the mounting member. A heat conductive layer may be provided between the substrate and the mounting member. According to the structure which concerns, the heat | fever of an LED light source can be efficiently propagated to an attachment member. Examples of the material of the heat conductive layer include silicone gel containing a metal filler, silicone gel, and acrylic elastomer.

(lens)
The lens is used for the purpose of controlling the light distribution of the LED light source. The material of the lens is not particularly limited as long as it is light transmissive, and synthetic resins such as acrylic resin, polyethylene terephthalate (PET), polycarbonate resin, silicone resin, and epoxy resin, and inorganic materials such as glass can be employed. The lens is disposed on the light emission side of the LED light source mounted on the substrate. The lens is positioned by bringing a part of the lens into contact with a predetermined position on the substrate. For example, it is possible to position the lens with respect to the substrate by providing an engaging portion that engages a part of the lens at a predetermined position of the substrate and engaging a part of the lens here. In this way, the lens is positioned with reference to the substrate on which the LED light source is mounted, rather than using other members such as a case as a reference for positioning the lens. Is less likely to occur, and light distribution control can be performed with high accuracy.

Although the lens can be formed integrally with a case described later, the lens and the case are separated. If the lens and the case are integrally formed of a transparent resin, there is a possibility that sink (distortion or deformation) may occur in the lens portion due to the case portion. In particular, sink marks tend to occur when the lens thickness is large. When sink marks occur in the lens, the lens accuracy decreases, and light distribution control by the lens is not performed well. For example, if a lens with low lens accuracy is used for an LED light source that emits white light by including a phosphor that emits yellow light by the light of the blue LED chip in the sealing member of the blue LED chip, Yellow light may be emitted separately and observed in different colors. Also, forming the lens positioning structure and the like integrally with the lens is one of the factors that cause the lens to sink. On the other hand, if a special member or the like for fixing the lens is used, the number of parts increases and the manufacturing process becomes complicated. Therefore, the lens is preferably formed integrally with a minimum positioning structure. This is because sink marks can be minimized without increasing the number of parts. In addition, you may perform a light-diffusion process to the surface into which light is introduced among the lens surfaces. In this way, color separation can be reduced. As a method of the light diffusion treatment, for example, a light diffusion treatment such as blasting or embossing can be performed on the surface of the lens. Further, a light diffusion treatment can be performed by disposing a sheet containing a light diffusing agent on the lens surface. Examples of the light diffusing agent include glass particles having a refractive index different from that of the lens, and transparent or white fine particles such as SiO ₂ and TiO ₂ .

(Case)
The case of the present invention is fixed to the mounting member with the lens and the substrate interposed therebetween. As a result, the substrate and the lens are sandwiched between the case and the mounting member. The case can be made of resin or metal, but is preferably made of a thermoplastic resin in terms of insulation, moldability, and heat caulking. The case includes a first locking claw and a second locking claw. The first locking claw fixes the case to the mounting member in the vertical axis direction relative to the mounting member (that is, the direction in which the substrate and the lens are sandwiched) and in the first horizontal axis direction horizontal to the mounting member. Similarly, the second locking claw fixes the case to the mounting member in the vertical axis direction with respect to the mounting member (that is, the direction in which the substrate and the lens are sandwiched) and in the second horizontal axis direction horizontal to the mounting member. As a result, the case is fixed to the mounting member from the three directions of the holding direction and the first and second axis horizontal directions, and the deviation or backlash of the case is reduced. Furthermore, the deviation or rattling of the substrate and lens sandwiched in this state is reduced. The first axis horizontal direction and the second axis horizontal direction are preferably orthogonal. This is because the displacement of the case is further reduced.
A plurality of first locking claws or second locking claws may be provided. For example, the case can be fixed by sandwiching the mounting member from the front-rear direction with the two first locking claws and sandwiching the mounting member from the left-right direction with the two second locking claws. In such a state, the case is fixed from the direction perpendicular to the mounting member, from the front and rear, and from the left and right directions of the mounting member, so that the deviation or rattling can be further reduced.

Before the case is fixed to the mounting member, the first protrusion and the second protrusion are formed on the case, and the first and second locking claws are formed from the first and second protrusions. can do. When fixing the case to the mounting member, a first locking claw is formed by abutting a pre-formed first protrusion on the side surface of the mounting member and turning a part of the first projection on the back surface of the mounting member. can do. Similarly, the second locking claw can be formed by bringing a second protrusion formed in advance into contact with the side surface of the mounting member and by bringing a part thereof around the back surface of the mounting member. For example, when the case is formed of a thermoplastic resin, the case can be fixed to the mounting member by deforming the first and second protrusions to form the first and second locking claws by heat caulking. it can. That is, a part of the first protrusion is softened (melted) and softened (melted) from the side surface side to the back surface side of the mounting member to be solidified, whereby the vertical first axis direction and the horizontal first direction with respect to the mounting member. A first locking claw for fixing the case to the mounting member in the horizontal axis direction can be formed. Similarly, a part of the second protrusion is softened (melted) and softened (melted) from the side surface side to the back surface side of the mounting member to be solidified, whereby a vertical second direction and a horizontal second direction with respect to the mounting member are obtained. A second locking claw for fixing the case to the mounting member in the horizontal axis direction can be formed.
When the case is made of metal, the first locking claw and the second locking claw can be formed by bending the first and second protrusions from the side surface to the back surface of the mounting member.

When the case is formed of a thermoplastic resin, the first and second protrusions may include a claw for temporarily fixing the attachment member. The temporarily fixing claws are temporarily locked to the back surface of the mounting member to temporarily fix the case and the mounting member while sandwiching the substrate and the lens. In the case where the case and the mounting member are not temporarily fixed, a step of temporarily fixing the mounting member and the case is necessary in order to prevent displacement when the first and second claws are caulked. However, by temporarily fixing the case and the attaching portion with the temporarily fixing claws, the step of temporarily fixing becomes unnecessary. This reduces work steps and improves manufacturing efficiency.
Hereinafter, the present invention will be described in more detail with reference to examples.

FIG. 1A shows an exploded perspective view of an LED lamp unit 1 according to an embodiment of the present invention, and FIG. 1B shows a perspective view after assembly. A cross-sectional view taken along line AA in FIG. 1B is shown in FIG. Moreover, the perspective view of the state before heat caulking about the back surface of the LED lamp unit 1 is shown in FIG. 3, the perspective view of the state in the middle of heat caulking is shown in FIG. 4A, and the side view is shown in FIG. Further, FIG. 5 shows a perspective view of the state after heat staking.
The LED lamp unit 1 is installed on the ceiling in the vehicle compartment and is used as a map lamp. As shown in FIG. 1A, the LED lamp unit 1 includes a case 10, a lens 2, a substrate 3, a heat conductive sheet 4, and a bracket 5 as an attachment member. The bracket 5 is made of aluminum, and has a base portion 51 and two holes 52 for fixing to the vehicle interior ceiling. The base portion 51 is substantially flat and has a front side portion 53 and left and right side portions 54. The heat conductive sheet 4 is a silicone gel containing a metal filler. The substrate 3 is an Al heat dissipating substrate on which an LED lamp 31, a constant current circuit (not shown), a connector 33, and the like are mounted. The connector 33 is connected to a power supply terminal (not shown). A circuit (not shown) is formed on the substrate 3, and the power supplied via the connector 33 is supplied to the LED lamp 31. Further, engaging portions 32 formed by omitting a part of the substrate 3 are formed on both sides of the substrate 3. The LED lamp 31 is a surface-mounted LED lamp that emits white light. The lens 2 is a convex lens and includes two positioning portions 21 at the edge thereof. The case 10 is made of PBT resin and includes a lens opening 13. Furthermore, the 1st projection part 11 is provided in the left side and the right side part 1 each, and the 2nd projection part 12 is provided in the front side part. The first and second projecting portions 11 and 12 are respectively provided with temporarily fixing claws 11a and 12a protruding inside the case.

As shown in FIG. 1A, the heat conductive sheet 4, the substrate 3 on which the LED lamp 31 is mounted, and the lens 2 are sequentially stacked on the bracket 5, and finally the case 10 and the bracket 5 sandwich the substrate 3 and the lens 2. The LED lamp unit 1 is assembled by covering the case 10. At that time, the lens 2 is positioned with respect to the substrate 3 so that the positioning portion 21 of the lens 2 is engaged with the engagement portion 32 of the substrate 3 and the lens 2 is disposed immediately above the LED lamp 31. Further, as shown in FIG. 2, the case 10 abuts the lens 2 at an edge 13 a that forms the opening 13. Further, as shown in FIG. 3, the first projecting portion 11 contacts the front side portion 53 of the bracket 5, and the second projecting portion 12 of the case 10 contacts the left and right side portions 54 of the bracket 5. In this state, the case 10 is temporarily fixed by engaging the temporarily fixing claws 11a and 12a of the first protruding portion 11 and the second protruding portion 12 with the back surface of the bracket 5 (see FIG. 3).
After the case 10 is temporarily fixed, as shown in FIG. 4A, the overheated jig 6 for heat caulking is pressed against part of the first and second protrusions. Thereby, the front-end | tip part of the 1st and 2nd projection parts 11 and 12 is softened (melted) (refer FIG. 4B). At this time, the shape of the jig 6 is L-shaped, and the jig 6 is pressed so that the L-shaped portion is along the front side portion 53 and the back surface of the bracket 5 or the left and right side portions 54 and the back surface. As a result, as shown in FIG. 5, the softened (melted) tip portions of the first and second projecting portions 11 and 12 are deformed along the back surface of the bracket 5. Thereby, the 1st latching claw 110 which contact | abuts the front side part 53 and the back surface of the bracket 5 and the 2nd latching claw 120 which contact | abuts the right-and-left side part 54 and a back surface are formed. As a result, the first locking claw 110 and the second locking claw 120 are fixed in a state where the case 10 and the bracket 5 sandwich the substrate 3 and the lens 2, and the LED lamp unit is assembled (see FIG. 1B). When the tips of the first and second protrusions 11 and 12 are softened (melted) by the jig 6, the temporarily fixing claws 11a and 12a are also softened (melted).

  In the LED lamp unit 1 configured as described above, the case 10 is fixed to the bracket 5 from three directions by the first and second locking claws 110 and 120. With such a simple configuration, deviation or rattling of the case 10 is reduced. At this time, the first locking claw 110 fixes the case 10 to the bracket 5 from the direction of the front side portion 53 of the bracket 5, and the second locking claw 110 fixes the case 10 to the bracket 5 from the direction of the front side portion 54 of the bracket 5. Fix it. That is, the first locking claw 110 and the second locking claw 120 both fix the case 10 to the bracket 5 in the direction perpendicular to the direction in which the substrate 3 and the lens 2 are sandwiched and in the axial direction perpendicular to each other. The deviation or shakiness of this will be further reduced. The lens 2 is clamped and fixed together with the substrate 3 by the case 10 and the bracket 5. At this time, the lens 2 is positioned and disposed immediately above the LED lamp 31 by the positioning portion 21 of the lens 2 engaging with the engaging portion 32 of the substrate 3. That is, the positioning of the lens 2 is not performed based on the case 10 or the bracket 5 but based on the substrate 3 on which the LED lamp 31 is mounted. As a result, the lens 2 and the LED lamp 31 are unlikely to be displaced or errored, and the lens 2 realizes highly accurate light distribution control. Furthermore, the lens 2 has only the positioning part 21 in addition to the lens part, and there is little possibility of causing the sink of the lens part. Therefore, the lens 2 maintains a high lens accuracy and enables a highly accurate light distribution control. On the other hand, the bracket 5 is made of a heat dissipating material. Thereby, the heat of the LED lamp 31 can be radiated from the bracket 5. Therefore, since a special structure for heat dissipation such as a heat sink is not required, the apparatus can be reduced in size. Further, since the number of parts is small, the manufacturing process is not complicated. Further, in the LED lamp unit 1, a heat conductive sheet 4 made of silicone gel is sandwiched between the substrate 3 and the bracket 5, and a heat conductive layer is formed. Thereby, the heat of the LED lamp 31 is efficiently propagated from the back surface of the substrate 3 to the bracket 5 and the heat dissipation characteristics of the device are improved. In addition, since the substrate 3 is an Al heat-dissipating substrate, the heat of the LED lamp 31 is further efficiently transmitted to the bracket 5, and thus a high heat-dissipating effect is achieved.

  The present invention is not limited to the description of the embodiments and examples of the invention described above. Various modifications are also included in the present invention as long as those skilled in the art can easily conceive without departing from the scope of the claims.

  The LED lamp unit of the present invention can be used for a room lamp or a spot lamp in a vehicle interior or living room.

FIG. 1A is an exploded perspective view of an LED lamp unit 1 according to an embodiment of the present invention. FIG. 1B is a perspective view of the LED lamp unit 1. FIG. 2 is a cross-sectional view taken along line AA of the LED lamp unit 1 in FIG. 1A. FIG. 3 is a perspective view of the back surface of the LED lamp unit 1 in a state before heat caulking. FIG. 4A is a perspective view of the back surface of the LED lamp unit 1 in a state where heat staking is performed. FIG. 4B is a side view of the LED lamp unit 1 in a state where heat caulking is in progress. FIG. 5 is a perspective view of the back surface of the LED lamp unit 1 in a state after heat caulking.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 LED lamp unit 10 Case 11 1st projection part 110 1st latching claw 12 2nd projection part 120 2nd latching claw 2 Lens 3 Board | substrate 31 LED lamp 4 Thermal conductive sheet 5 Bracket

Claims (5)

A mounting member made of a thermally conductive material;
A substrate disposed on the mounting member;
An LED light source mounted on the substrate;
A lens disposed on the light emitting side of the LED light source, a part of which is positioned with respect to the substrate by contacting the substrate;
A first locking claw and a second locking claw, and a case fixed to the mounting member,
The substrate and the lens are sandwiched between the mounting member and the case, and the first locking claw fixes the case to the mounting member in a vertical axis direction and a first horizontal axis direction with respect to the mounting member, The second locking claw is an LED lamp unit that fixes the case to the mounting member in a vertical axis direction and a second horizontal axis direction with respect to the mounting member.   The LED lamp unit according to claim 1, wherein the first horizontal axis direction and the second horizontal axis direction are orthogonal to each other.   The LED lamp unit of Claim 1 or 2 provided with a heat conductive layer between the said attachment member and the said board | substrate.   The said 1st latching claw and the said 2nd latching claw are formed in any one of Claims 1-3 by heat-caulking the 1st projection part and the 2nd projection part which were previously formed in the said case. LED lamp unit.   The LED lamp unit according to claim 4, wherein the first protrusion and the second protrusion have a claw for temporarily fixing the case to the mounting member.

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