JP7218681B2 - Light emitting device and manufacturing method thereof - Google Patents

Description

The present invention relates to a light-emitting device and a manufacturing method thereof.

2. Description of the Related Art Conventionally, a light emitting device as a linear light source using a rod-shaped light guide has been known (see, for example, Patent Document 1). The light emitting device described in Patent Document 1 is a vehicle lamp for illuminating the exterior of a vehicle, and is installed along the edge of a front grill on the front surface of the vehicle, for example.

Further, in the light emitting device described in Patent Document 1, a rod-shaped light guide is accommodated inside the connected case and lens. prevent intrusion into the interior of the The case and the lens are connected by engaging claws provided on the lens with engaged portions provided on the case.

JP 2016-4755 A

In the light-emitting device described in Patent Document 1, it is necessary to secure the claw portion of the lens, the engaged portion of the case, and the installation area for the waterproof material. A gap needs to be provided between the case and the light guide for reflection, which increases the width of the light emitting device compared to the width of the light guide. Therefore, it is difficult to install a light emitting device on a member having a small width.

It is also possible to weld the lens and case together, but if this method is used, in order to ensure the safety of the operator, a certain amount of width must be provided around the welded part so that burrs generated by welding do not protrude. It is necessary to establish a department. Also in this case, it is necessary to provide a gap between the case and the light guide in order to secure an air layer. Furthermore, the case and the light guide must have a shape such that the parts other than the welded part do not come into contact with the welding jig. This also increases the width of the light emitting device compared to the width of the light guide.

One of the objects of the present invention is to provide a light emitting device as a linear light source using a rod-shaped light guide, which is waterproof and has a small width, and a manufacturing method thereof.

In order to achieve the above objects, one aspect of the present invention provides the following light-emitting devices [1] to [6] and methods for manufacturing the same.

[1] A light-emitting element, a light-guiding region for propagating light incident from the light-emitting element to the inside, and a lens formed continuously with the light-guiding region and extracting the light propagating inside the light-guiding region to the outside. a light guide body having an area; a sealing member fixed in close contact with the lens area; covering the light guide area via an air layer; and a cover covering the surface up to the lens area.
[2] The light-emitting device according to [1], wherein the sealing member is welded to the lens region.
[3] The light-emitting device according to [1] or [2] above, wherein the cover is made of a material different from that of the light guide.
[4] The light-emitting device according to any one of [1] to [3], wherein the sealing member has a melting temperature lower than that of the light guide.
[5] Any one of [1] to [4] above, wherein the light guide is rod-shaped, and the light-emitting element is arranged to face the rod-shaped end of the light guide. luminous device.
[6] A light guide region having a light guide region that internally propagates light incident from a light emitting element, and a lens region that is formed continuously with the light guide region and extracts the light propagating inside the light guide region to the outside. a sealing member welding step of welding a sealing member to the lens region of the body; welding a cover to the sealing member to cover the light guide region via an air layer; and covering the light guide region to the lens region. and a cover molding step of covering with the cover.

ADVANTAGE OF THE INVENTION According to this invention, it is a light-emitting device as a linear light source using a rod-shaped light guide, and can provide the light-emitting device which has waterproofness and a small width, and its manufacturing method.

FIG. 1 is a top view of a light emitting device according to an embodiment of the invention. FIG. 2 is a vertical cross-sectional view of the light-emitting device taken along line AA in FIG. FIG. 3 is a vertical cross-sectional view of the light-emitting device in which FIG. 2 is partially enlarged. FIG. 4 is a cross-sectional view of the light-emitting device taken along line BB in FIG. FIGS. 5A and 5B show a method of manufacturing a light emitting device, FIG. 5A is a diagram of a sealing member, which is an insert part, set in a mold, and FIG. 5B is a diagram of a molded light guide. FIG. 5(c) is a view of the light emitting device completed by insert-molding the cover using the light guide body to which the sealing member is welded as an insert part. FIG. 6 is a view corresponding to FIG. 4, showing a second embodiment. FIG. 7A is an example of a member (design member) to which the light emitting device 1 is attached when the light emitting device 1 is applied to a vehicle, and is a schematic diagram of the front grille 20 of the vehicle. FIG. 7B is a cross-sectional view of the light emitting device 1 installed on the front grill 20. FIG.

[First Embodiment]
(Structure of Light Emitting Device According to Embodiment of the Present Invention)
A light emitting device 1 according to an embodiment of the present invention is a linear light source capable of emitting linear light. Further, since the light emitting device 1 itself has a small width, it can be attached to a member having a small width.

A light-emitting device 1 according to an embodiment of the present invention includes a light-emitting element 14, a light-guiding region 10a through which light 14a incident from the light-emitting element 14 is propagated, and a light-guiding region formed continuously with the light-guiding region 10a. A light guide 10 having a lens region 10b for extracting light 14a propagating inside 10a to the outside, a sealing member 19 fixed in close contact with the lens region 10b, and an air layer 18 covering the light guide region 10a. , and a cover 11 that is closely connected to the sealing member 19 and covers the surface from the light guide region 10a to the lens region 10b.

In the above structure, as shown in FIGS. 1 and 2, the light guide 10 is rod-shaped, that is, elongated, and the light-emitting element 14 is arranged to face the rod-shaped end of the light guide 10. .

(Light guide 10)
The light guide 10 has a light guide region 10a and a lens region 10b. The light guide region 10a and the lens region 10b are continuous between both ends of the light guide 10 in the length direction. Taking the central axis CL in the extending direction of the rod shape shown in FIGS. It continues for a predetermined bar-like length in the direction of the central axis CL. That is, the shape of the light guide region 10a and the lens region 10b is also rod-like, and the length direction of the light guide region 10a and the lens region 10b matches or substantially matches the length direction of the light guide 10. FIG.

The rod-shaped "bar" that is the shape of the light guide 10 includes not only a straight bar but also a polygonal bar and a curved bar. It can take a shape according to the shape of the member.

Light 14a emitted from the light emitting element 14 and taken into the light guide 10 through the light intake surface 10c enters the light guide area 10a through the area 10j connecting the light intake surface 10c and the light guide area 10a. , propagate along the length of the light guide region 10a. As shown in FIG. 2, the light intake surface 10c is typically located at one end in the length direction of the light guide 10 at approximately the same height as the light guide region 10a (vertical position in FIG. 2). provided in

The shape of the light guide region 10a is, for example, a cylindrical shape or a prismatic shape (for example, a rectangular parallelepiped). is preferred. When the light guide region 10a is cylindrical, the light reflected in the light guide region 10a passes through the center axis of the light guide region 10a, so the light guide distance is constant, and the change in the light emission intensity of the light emitting device 1 over time is reduced. become smaller. On the other hand, when the light guide region 10a is rectangular, the light reflected in the light guide region 10a does not necessarily pass through the center of the light guide region 10a. Emission intensity tends to increase or decrease over time. Regardless of whether the light guide region 10a has a cylindrical shape or a prismatic shape, the uniformity (uniformity) of the light emission intensity distribution of the light emitting device 1 can be corrected by a plurality of steps 10e as described later. can be done.

The lens region 10b is a region having a light extraction surface 10d for extracting light propagating inside the light guide region 10a to the outside on the opposite side of the light guide region 10a.

The shape of the lens region 10b is typically rectangular parallelepiped as shown in FIGS.

In order to efficiently guide the light into the light guide region 10a, the width of the lens region 10b (the length in the vertical direction in FIG. 1 and the length in the horizontal direction in FIG. 4) should be smaller than the width of the light guide region 10a. is preferred.

The light guide region 10a preferably has a plurality of steps 10e on the opposite side of the lens region 10b, as shown in FIGS. A plurality of steps 10e are provided continuously along the length direction of the light guide region 10a. For example, as shown in FIG. 3, the step 10e is formed as a continuous recessed step from the outside toward the inside on the bottom surface of the light guide region 10a located on the opposite side of the light extraction surface 10d. Various shapes such as a mountain-shaped concave shape, a cylindrical concave shape, and a pyramid concave shape are possible for the concave shape.

The step 10e can facilitate reflection of the light 14a propagating in the light guide region 10a toward the light extraction surface 10d of the lens region 10b. Further, by adjusting the shape of the plurality of steps 10e so that the more light is reflected on the steps 10e as the distance from the light intake surface 10c increases, the uniformity of the light emission intensity distribution of the light emitting device 1 is improved. can be made

The light guide 10 is made of a transparent material such as polycarbonate (PC) or polymethyl methacrylate (PMMA) that allows the light 14a emitted from the light emitting element 14 to pass therethrough.

As shown in FIG. 4, the lens area 10b of the light guide 10 may have a protrusion 10g in the area covered with the first cover 11 on the side surface 10f. The protrusion 10g is a linear protrusion extending along the length direction of the lens region 10b. Moreover, it is preferable that the protrusions 10g are also formed on the end faces in the length direction of the lens regions 10b.

By providing the protrusion 10g, the intrusion path of water or the like can be extended and bent to prevent intrusion of water from the outside. In addition, since the welded portion (welded area) with the sealing member 19 described below can be increased, the sealing performance of the air layer 18 can be improved.

In the present embodiment, although the protrusion 10g is not essential, the configuration provided with the protrusion 10g will be described due to the effect described above.

As shown in FIG. 4, a sealing member 19 is fixed in close contact with the lens region 10b of the light guide 10. As shown in FIG. The sealing member 19 is welded to the lens area 10b. The sealing member 19 is also welded to the protrusion 10g described above.

The sealing member 19 is made of a material whose melting temperature is lower than that of the light guide 10 . As a result, the sealing member 19 is melted during insert molding, which will be described later, and is welded and adhered to the light guide 10 .

Also, the sealing member 19 can be made of the same material as the cover 11 . Since the sealing member 19 is used as an insert part and integrally molded with the light guide 10 whose melting temperature is higher than that of the sealing member 19, the adhesion between the sealing member 19 and the light guide 10 can be ensured.

(Cover 11)
The cover 11 covers the surface of the light guide region 10a with an air layer 18 interposed therebetween. Therefore, the surface of the light guide region 10a is covered with the air layer 18. As shown in FIG. Since the cover 11 covers the entire surface of the light guide region 10a, as shown in FIG. 4, it is preferable that the end of the cover 11 covers a part of the side surface 10f of the lens region 10b on the light guide region 10a side. . Here, the side surfaces 10f are surfaces along the length direction of the lens region 10b on both sides of the light extraction surface 10d.

As shown in FIG. 4, the end portion 11a of the cover 11 is tightly connected to the sealing member 19. As shown in FIG. The end portion 11a of the cover 11 is welded to the sealing member 19 by insert molding, which will be described later. It is also welded to the protrusion 10g of the light guide 10 described above.

The refractive index of air is 1.0, which is less than the refractive index of the light guide 10 (for example, approximately 1.6 when made of PC and approximately 1.5 when made of PMMA). By totally reflecting the light at the interface of the layer 18, attenuation of the light propagating in the light guide region 10a can be suppressed. In addition, since the refractive index of air is smaller than the refractive index of the cover 11 (for example, about 1.5 when made of PP), the difference between the refractive index of the light guide 10 and the cover 11 is large. The critical angle is smaller than in the case of being in close contact with the substrate, making it easier to satisfy the condition of total internal reflection. Therefore, it is possible to suppress a decrease in emission intensity in a region distant from the light intake surface 10c.

The cover 11 can be formed by insert molding or two-color molding using a material having poor adhesion to the light guide 10 and using the light guide 10 as a base member. According to this method, since the light guide 10 and the cover 11 are not in close contact with each other, a gap, that is, an air layer 18 is naturally formed between the light guide 10 and the cover 11 .

A material having poor adhesion to the light guide 10 is, for example, a material different from the material forming the light guide 10 . For example, when the light guide 10 is made of PC or PMMA, it is preferable to use polypropylene (PP) as the material of the cover 11 from the viewpoint of poor adhesion and cost.

In order to efficiently reflect the light not reflected at the interface between the light guide 10 and the air layer 18, the cover 11 is preferably a white member containing a white dye such as titanium oxide. If it is desired to avoid seeing white when the light-emitting device 1 is not lit, the cover 11 may be a black member containing a black dye such as carbon black.

(Manufacturing method of light-emitting device 1)
In the method of manufacturing the light emitting device 1, first, a sealing member welding process is performed to form a light guide region 10a through which light incident from the light emitting element 14 is propagated, and an inner portion of the light guide region 10a formed continuously with the light guide region 10a. A sealing member 19 is welded to the lens region 10b of the light guide 10 having the lens region 10b for extracting the light propagating through the light source 10 to the outside. Next, in a cover molding process, the cover is welded to the sealing member 19 to cover the light guide region 10a via an air layer, and the cover 11 covers the surface from the light guide region 10a to the lens region 10b.

As shown in FIG. 5(a), the sealing member 19, which is an insert part, is set in a mold (not shown). The sealing member 19 is set at a predetermined position of the light guide 10 by positioning to the mold. In this embodiment, the light guide 10 is set at a position where it abuts on the protrusion 10g.

Next, the melted light guide 10 is injected into a mold (not shown) to perform insert molding of the light guide 10 . Here, a material having a melting temperature lower than that of the light guide 10 is used for the sealing member 19 . As a result, the sealing member 19 is melted during the insert molding and welded to the light guide 10 so as to adhere thereto.

By the sealing member welding process described above, the light guide body 10 in which the sealing member 19 is welded to the lens region 10b, as shown in FIG. 5(b), is formed.

Next, the cover 11 is insert-molded using the light guide 10 with the sealing member 19 welded to the lens region 10b as an insert part. The cover 11 is made of a material having poor adhesion to the light guide 10, for example, a material that does not contain the material constituting the light guide 10, so that the light guide 10 and the cover 11 are not in close contact with each other. A gap or air layer 18 is naturally formed between the body 10 and the cover 11 .

Further, for example, by using the same material for the sealing member 19 as the cover 11, the adhesion between the sealing member 19 and the light guide 10 can be ensured.

By the above-described cover molding process, an integrated structure is completed in which the cover 11 covers the light guide 10 via the air layer 18 and the sealing member 19 seals the air layer 18, as shown in FIG. 5(c).

In addition to the above steps, the light emitting device 1 is completed by attaching the light emitting element 14, the heat sink 16, and the like.

(Light emitting element 14)
An LED is typically used as the light emitting element 14 . An LED is a small light-emitting element, consumes little power, generates little heat, and has a long life. Note that the light emitting elements 14 may be installed at both ends of the light guide 10 in the length direction. In that case, light intake surfaces 10c are provided at both ends of the light guide 10 in the length direction.

A light emitting element 14 is mounted on the substrate 13 . The substrate 13 is a wiring substrate having wirings connected to the electrodes of the light emitting elements 14 .

The substrate 13 has holes 13a for positioning. A protrusion 10i that is a part of the light guide 10 is inserted into the hole 13a to determine the position of the substrate 13 with respect to the light guide 10, that is, the position of the light emitting element 14 with respect to the light guide 10. FIG. The positioning of the light emitting element 14 with respect to the light guide 10 is important for efficiently guiding the light emitted from the light emitting element 14 into the light guide 10 .

The projection 10i for positioning the substrate 13 may be provided as a part of (the housing 15 that is a part of) the cover 11, but as described above, the position of the light emitting element 14 with respect to the light guide 10 is Because of its importance, the protrusion 10i is preferably part of the lightguide 10. FIG.

A housing 15 that houses the light emitting element 14 is a part of the cover 11 and prevents light leakage to the outside.

The heat sink 16 is a heat radiation member for releasing heat generated from the light emitting element 14 and is fixed to the housing 15 . The substrate 13 is fixed to the heat sink 16 directly or via another layer.

Moreover, it is preferable that the space in the housing 15 be sealed by an annular sealing member 17 installed between the housing 15 and the heat sink 16 . The sealing member 17 is, for example, an O-ring or packing, and exhibits a sealing function by sandwiching the sealing member 17 between the housing 15 and the heat sink 16 and compressing it appropriately.

[Second embodiment]
2nd Embodiment is the structure which provided the 2nd cover 12 on the outer side of the cover 11 as the 1st cover shown in 1st Embodiment.

Further, a second cover 12 is insert-molded on the light emitting device 1 manufactured in the first embodiment. The second cover 12 can be welded to the cover 11 to cover the cover 11 .

By using the second cover 12 to seal the air layer 18 between the light guide 10 and the cover 11, it is possible to prevent water from entering the air layer 18 more reliably. Since water has a higher refractive index than air, when water enters the air layer 18, it becomes difficult to satisfy the conditions for total reflection.

For the second cover 12, a material having good adhesion to the cover 11 can be used. The second cover 12 can use polypropylene (PP), which is the same material as the cover 11, for example. As a result, the second cover 12 is brought into close contact with the cover 11 to cover the entire cover 11, thereby improving the airtightness.

(Usage example of light emitting device 1)
FIG. 7A is an example of a member (design member) to which the light emitting device 1 is attached when the light emitting device 1 is applied to a vehicle, and is a schematic diagram of the front grille 20 of the vehicle. FIG. 7B is a cross-sectional view of the light emitting device 1 installed on the front grill 20. FIG.

The front grille 20 has a frame 21 and a mesh 22 installed within the frame. The openings in the mesh 22 function as air intakes for drawing air into the vehicle's engine and radiator.

In the example shown in FIG. 7A, the mesh 22 is composed of a linear portion 22a extending in the vertical direction and a linear portion 22b extending in the horizontal direction, and the light emitting device 1 is installed on the linear portion 22a. In FIG. 7A, an example of the installation position of the light emitting device 1 is schematically shown by dotted lines.

The light emitting device 1 is installed on the back side of the linear portion 22a of the mesh 22, and the light extraction surface 10d of the light emitting device 1 is exposed through the linear opening provided in the linear portion 22a. Thereby, the linear portion 22a can be caused to linearly emit light.

When the light-emitting device 1 is installed on the front grille 20, the width of the light-emitting device 1 is small, so it does not protrude from the linear portion 22a and deteriorate the aesthetic appearance. Moreover, since the opening area of the mesh 22 is not narrowed, the intake function of the front grille is not deteriorated.

For example, as shown in FIG. 7(b), the light emitting device 1 is fixed to the intersection of the linear portions 22a and 22b of the mesh 22 by screwing. Specifically, the screw fixing portion 24 provided on the back side of the intersection of the linear portion 22a and the linear portion 22b of the mesh 22 and the projection 11c for screwing which is a part of the cover 11 are screwed together. 25.

Since the light-emitting device 1 is excellent in waterproofness, it can be installed in a place where water adheres, such as an exterior part of a vehicle. In addition to the front grille, examples of vehicle installation locations include design members such as plated moldings and garnishes, and gaps between garnishes and the body.

(Effect of Embodiment)
According to the light emitting device 1 of the above embodiment, the cover 11 can easily form a thin air layer 18 that covers the rod-shaped light guide 10, and the sealing member 19 can ensure waterproofness. Therefore, it is possible to provide a light emitting device as a linear light source using a rod-shaped light guide, which is waterproof and has a small width.

The light emitting device 1 configured by the light guide 10, the cover 11, and the sealing member 19 can be made smaller in width than a conventional light emitting device in which the light guide is housed inside a lens and a case. It can be installed even on a small member without impairing its function and aesthetic appearance.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Moreover, the above embodiments do not limit the invention according to the scope of claims. Also, it should be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

Reference Signs List 1 Light emitting device 10 Light guide 10a Light guide area 10b Lens area 10c Light intake surface 10d Light extraction surface 10e Step 10f Side surface 10g Protrusion 10i Protrusion , 10j area 11 cover 11a end 11c projection 12 second cover 13 substrate 13a hole 14 light emitting element 14a light 15 housing 16 heat sink 17 sealing member 18 Air layer 19 Sealing member 20 Front grill 21 Frame 22 Mesh 22a Linear portion 22b Linear portion 24 Screw fixing portion 25 Screw

Claims (6)

a light emitting element;
A light guide body having a light guide region for propagating light incident from the light emitting element inside, and a lens region continuously formed in the light guide region and extracting the light propagating inside the light guide region to the outside. ,
a sealing member fixed in close contact with the lens area;
a cover that covers the light guide area via an air layer, is closely connected to the sealing member, and covers the entire surface of the light guide area and a part of the surface of the lens area on the light guide area side ;
has
The lens area of the light guide has a linear protrusion extending along the length direction of the lens area in the area covered with the cover.
Luminescent device. 2. The light emitting device of claim 1, wherein the sealing member is welded to the lens area. 3. The light emitting device according to claim 1, wherein said cover is made of a material different from a material forming said light guide. 4. The light emitting device according to any one of claims 1 to 3, wherein the sealing member has a melting temperature lower than that of the light guide. 5. The light emitting device according to claim 1, wherein said light guide is rod-shaped, and said light emitting element is arranged to face said rod-shaped end of said light guide. a light guide region for propagating light incident from the light emitting element to the inside; and a lens region formed continuously with the light guide region for extracting the light propagating inside the light guide region to the outside , wherein the lens region a sealing member welding step of welding a sealing member to the lens region and the projection of the light guide body, in which a linear projection extending along the length direction is formed on the surface of the
A cover is welded to the sealing member to cover the light guide region via an air layer, and the entire surface of the light guide region to a part of the light guide region side including the protrusion on the surface of the lens region is covered with the light guide region. A cover molding process for covering with a cover ,
In the cover molding step, the cover is insert-molded using the light guide body to which the sealing member is welded as an insert part.
A method for manufacturing a light-emitting device.

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