JPH06112536A - Light source device and its manufacture - Google Patents

Abstract

PURPOSE:To provide a light source device in which the width of a linear light source can be made as narrow as possible while the size of the wiring pattern of LED elements is secured. CONSTITUTION:The title device in which an LED element group constituted by arranging a plurality of LED elements 2 on a substrate 4 is used as a linear light source is constituted of a flexible wiring board 4 on which the elements 2 are mounted along the center line of the substrate 4 so that the LED element group can be formed and both face sections 4b and 4c of which are bent at an obtuse angle larger than 90rt. angle so that the sections 4b and 4c can be faced to each other and a synthetic resin body 6 with which the space formed by the bent face sections 4b and 4c is filled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for use as a light source which emits light in a linear form by being incorporated in various office automation equipment and automobile instruments, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a fluorescent lamp has been used as a light source device of this kind. However, the fluorescent lamp requires a lighting circuit, which increases the cost due to the increase in the number of parts. Due to the unique lighting characteristics, there is a disadvantage in that the desired amount of light cannot be obtained immediately after the switch is turned on. For this reason, recently, instead of the fluorescent lamp, a light source device in which a plurality of LED elements are linearly arranged has become widespread. FIG. 5 is a sectional view showing a conventional example using an LED element. Reference numeral 20 indicates an LED element, and this LED
The elements 20 are arranged in a line in a predetermined number along the center line of the substrate 21 and wired. In this way, the LED element 20
The substrate 21 incorporating the linear LED element group of is housed together with the diffusion plate 24 inside the case 22 in which the window portion 23 is formed.
It is shielded so that the light from 0 does not disperse. Therefore, the light is transmitted through the head portion 24a of the diffuser plate 24 formed so as to be exposed from the window portion 23 of the case 22 to form linear light.

[0003]

Problems to be Solved by the Invention Recent OA equipment or automobile instruments are becoming smaller and more compact. Therefore, the L used for these
The light source of the ED element is also required to be further downsized. In particular, when used as a pointer light source for automobiles, it is required to be literally needle-shaped, and the narrower the width of the light source, the more suitable it is as a pointer light source. In order to reduce the size of such a light source device, it is not possible to ignore the restrictions associated with the processing of the components, especially the processing of the substrate. For example, if the entire width A is several millimeters in the example of FIG. 5, the efficiency of punching the outer shape of the substrate 21 with the press die becomes extremely poor, and in some cases, punching itself becomes impossible. . For this reason, it is necessary to cut a press-molded product with an external dimension having a certain allowance to a desired size by cutting or the like, which causes a problem that the number of steps is significantly increased. Further, when the LED elements 20 are arranged in a row on the substrate 21, the workability is extremely deteriorated due to the extremely narrow width, and there is a drawback that the other LED elements 20 already assembled are damaged. Therefore, the present invention solves the above-mentioned problems of the conventional technology, and a method of manufacturing a light source device capable of making the width of the light source as narrow as possible while ensuring the size of the wiring pattern of the LED element, and a method of manufacturing the light source. An object is to provide a light source device whose width is as narrow as possible.

[0004]

In order to achieve the above-mentioned object, the present invention is a light source device in which a line-shaped light source is an LED element group formed by arranging a plurality of LED elements on a substrate. A plurality of LED elements are mounted so as to form an LED element group along a line, and a flexible wiring board bent at an obtuse angle of 90 degrees or more so that side surfaces on both sides face each other, and bent wiring It is composed of a synthetic resin body filled inside the substrate.

In order to achieve the above-mentioned object, the present invention further comprises a step of arranging a plurality of LED elements on a flexible wiring board along the center line of the board, and a step of arranging the LED elements on both sides of the wiring board. It is composed of a step of bending the side surface portion inward by 90 ° or more and a step of filling the inside of the bent wiring board with resin.

[0006]

According to the present invention, the side portions on both sides of the wiring board are
Since the width of the line-shaped light source formed on the edges of both side surfaces is made as narrow as possible by bending at an obtuse angle of 0 degree or more, the line-shaped light source can be used even if a wiring pattern of the same size as the conventional one is used. Can be made extremely narrow,
A drastic downsizing of the entire light source device can be achieved.
Further, the wiring board is substantially a case, and the resin body is
It acts as a protective material for the ED element and as a light diffusing material. In particular, by forming the exposed head portion of the resin body into a convex surface, this head portion functions as a convex lens.

Further, according to the present invention, since the LED element is mounted on the wiring board and then the wiring board is bent, the electric wiring pattern of the wiring board 4 is not narrowed in accordance with the width of the light source. The LED element can be mounted, and the workability of the LED element mounting work is significantly improved.
Further, after the wiring board is bent and filled with resin, the bent shape of the wiring board is fixed by this resin.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment in which the present invention is applied to a pointer of a measuring instrument for automobiles. Reference numeral 2 indicates an LED element, and the LED elements 2 are arranged along the center line of the wiring board 4 in a predetermined number in a line to form an LED element group. Like this
The wiring board 4 on which the ED element 2 is mounted is a single flat flexible wiring board composed of a bottom surface portion 4a and left and right side surface portions 4b and 4c, and a press die is used as described later. By bending both side surface portions 4b, 4c at an obtuse angle of 90 degrees or more, an opening 5 is formed at the edge of each side surface portion 4a, 4b. Further, the inside of the wiring board 4 is filled with transparent synthetic resin instead of the conventional diffusion plate to form the synthetic resin body 6.

In this embodiment, the head portion 6a of the synthetic resin body 6 is adapted to project from the opening 5 of the wiring board 4 to the outside. The head portion 6a extends in a direction perpendicular to the drawing so as to face the array of the LED elements 2, 2, ... Mounted on the bottom surface of the wiring board 4, whereby the LED elements are formed. The light from 2 is transmitted through the synthetic resin body 6 to form linear light. The outer surface of the wiring board 4 is coated with a black cover, so that the LE penetrates through the wiring board 4.
The light of the D element 20 is shielded so as not to leak.

However, according to the embodiment configured as described above, both side surface portions 4a, 4c of the wiring board 4 are bent at an obtuse angle of 90 degrees or more to form both side surface portions 4a, 4c.
Since the width B of the opening 5 formed at the edge of b is as narrow as possible, the line light source can be made extremely narrow even if the wiring pattern of the same size as the conventional one is used. ,
Moreover, it is possible to achieve a drastic downsizing of the entire light source device.

Further, the bent wiring board 4 substantially serves as a case, while the resin body 6 protects the LED element 2 and acts as a light diffusing material. No need for parts such as
The number of parts can be reduced.

Next, the manufacturing process of the light source device according to this embodiment will be described with reference to FIG.

First, as shown in FIG. 2A, the LED elements 2 corresponding to the number of LED arrays are bonded to the wiring board 4 in a line along the center line of the board. Next, as shown in FIG. 2B, the wiring board 4 is U-shaped in cross section, that is, both side surface portions 4a and 4b are bent inward by 90 ° by using a jig 8. After that, as shown in FIG. 2C, the wiring board 4 taken out from the jig 8 is set in a resin injection mold this time. In this embodiment, the resin injection mold is composed of left and right movable molds 10a and 10b and a lower mold 12 which is fixed in advance. The movable molds 10a and 10b have inclined surfaces 1 that are inclined in accordance with the bending angle of the wiring board 4.
1a and 11b are formed, the wiring board 4 bent in the U-shape in the lower mold 12 is formed into the movable molds 10a and 10b.
The wiring board 4 can be easily bent by clamping the mold by sandwiching it. Finally, Figure 2
As shown in (d), resin is injected from the injection part 13 between the movable molds 10a and 10b. After that, the resin can be cured and the mold can be opened to take out the product.

In the manufacturing process as described above, the LED element 2
Since the wiring board 4 is bent after being bonded to the wiring board 4, the LED element 2 can be mounted without narrowing the electric wiring pattern of the wiring board 4 in advance in accordance with the width of the light source. Therefore, the workability of the LED element mounting work is significantly improved. In addition, after the wiring board 4 is bent and filled with the resin, the bent shape of the wiring board is fixed by the resin, so that there is no work such as fixing the bent portion as an additional step.
Since the light source devices can be efficiently mass-produced with a small number of steps, the manufacturing cost can be reduced.

Next, another embodiment will be described with reference to FIGS. The embodiment of FIG. 3 is an embodiment in which the wiring board 13 is bent at a substantially right angle and the head portion 15 of the resin body 14 is formed into a convex surface. By making the shape of the head portion 15 of the resin body 14 particularly convex as in this embodiment, since the head portion 15 acts as a convex lens, a lens effect is added without providing a convex lens as in the conventional case. be able to.

On the other hand, the embodiment of FIG. 5 is an embodiment configured as an LED light source for surface mounting. In this embodiment, the wiring board 1 to which the LED element 2 is bonded
6 is bent by approximately 90 ° toward the side opposite to the mounting side of the LED element 2. As a result, the resin body 15 is filled inside the wiring board on the side opposite to the LED element 2. Reference numeral 17 indicates a resin cover. Also in this embodiment, the line light source can be made to have a remarkably narrow width while using the wiring pattern of the same size as the conventional one, as in the embodiment of FIG.

[0017]

As described above, according to the present invention, the width of the line-shaped light source formed at the edges of both side surface portions can be changed by bending the side surface portions on both sides of the wiring board at an obtuse angle of 90 degrees or more. Since it becomes as narrow as possible, the line-shaped light source can be made extremely narrow even if a wiring pattern of the same size as the conventional one is used, and the size of the entire light source device can be significantly reduced. . In addition, since the wiring board substantially serves as a case and the resin body acts as a protective material for the LED element and as a light diffusing material, these parts are not required, and the number of parts is reduced to provide an inexpensive light source device. can do.

Since the LED element is mounted on the wiring board and then the wiring board is bent, the LED element can be mounted without narrowing the electric wiring pattern of the wiring board 4 according to the width of the light source. Therefore, the workability of the LED element mounting work is significantly improved. Further, after the wiring board is bent and filled with resin, the bent shape of the wiring board is fixed by this resin. Therefore, the light source device can be efficiently mass-produced with a small number of steps without the work of fixing the bent portion as an additional step, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a light source device according to the present invention.

FIG. 2 is an explanatory view of each step of the method for manufacturing a light source device according to the present invention.

FIG. 3 is a sectional view of another embodiment of the light source device according to the present invention.

FIG. 4 is a sectional view of another embodiment of the light source device according to the present invention.

FIG. 5 is a cross-sectional view of a conventional light source device.

[Explanation of symbols]

 2 LED element 4 Wiring board 4b, 4c Side part 6 Resin body 6a Head 8 Jig 10a, 10b Movable type 12 Fixed type 15 Convex surface

Claims (3)

[Claims] 1. A light source device using an LED element group formed by arranging a plurality of LED elements on a substrate as a linear light source,
A flexible wiring board in which a plurality of LED elements are mounted so as to form an LED element group along the center line of the wiring board, and the side surfaces on both sides are bent at an obtuse angle of 90 degrees or more so as to face each other. A light source device having a synthetic resin body filled inside a bent wiring board. 2. The light source device according to claim 1, wherein a head portion of the synthetic resin body exposed from the wiring board to the outside is formed into a convex surface. 3. A step of arranging a plurality of LED elements on a flexible wiring board along a board center line, and a step of bending side surfaces on both sides of the wiring board on which the LED elements are mounted by 90 ° or more inward. A method of manufacturing a light source device, comprising the step of filling a resin into the inside of a bent wiring board.