JPH06130878A - Light emitting device - Google Patents

Abstract

PURPOSE:To decrease the number of parts of the light emitting device which irradiates a prescribed points with the light from LEDs 2, to improve its workability thereof and to enhance its reliability. CONSTITUTION:This light emitting device has the chip LEDs 2 of a surface packaging type mounted on a substrate 1 and a light shieldable case 3 disposed to cover the chip LEDs 2 and is constituted by providing a light transmission body 4 for leading the light from the chip LEDs 2 to the outside of the case within the light shieldable case 3. plural pieces of the chip LEDs 2 are disposed zigzag.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED light emitting device used as a charge eliminating light source for a copying machine or a laser beam printer.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 5 is a perspective view of an LED chip mounting board according to a conventional example, and FIG. 6 is a side view showing a state where the LED chip mounting board of FIG. 5 is attached to a control board.

Conventionally, as shown in FIG. 5, a plurality of LED chips 11 (bare chips, openings of about 0.3 mm) are directly bonded to a chip mounting substrate 10 plated with gold in a line, and a gold wire 11 'is further provided. Wire bond with.

Next, as shown in FIG. 6, the LED chip 1
Chip mounting board 10 on which the driver IC 1
Flexible board 14 to control board 13 on which 2 is mounted
Or connect with a connector. Reference numeral 15 is a reflection case for efficiently emitting light.

Here, the chip mounting board 10 and the control board 1
The reason that 3 is a separate substrate is to obtain a necessary irradiation direction of light. That is, the irradiation direction of light is adjusted by changing the connection angle of both substrates.

[0006]

By the way, in the LED light emitting device according to the prior art, as described above, the bare LED chip 11 itself is directly bonded to the chip mounting substrate 10, and then the gold wire is wire bonded. Since the control board 13 separate from the chip mounting board 10 is provided to change the light irradiation direction, and both boards are connected by a flexible board or the like, the number of parts increases and bonding is performed. There are many factors that increase the cost, such as the need to plate the substrate with gold.

Further, since the number of bare type LED chips is large, there is a problem that the occurrence rate of wire bonding defects is high and the workability is poor.

Therefore, an object of the present invention is to realize a highly reliable LED light emitting device which is excellent in workability and has no defective bonding.

[0009]

In order to achieve the above object, the present invention provides a surface mount type chip LE mounted on a substrate.
D, and a light-shielding case provided on the substrate so as to cover the chip LED, and a light guide body for guiding light from the chip LED to the outside of the case is provided inside the light-shielding case. It is characterized by

Further, a plurality of the chip LEDs are arranged in a zigzag pattern.

[0011]

Since the light emitting device of the present invention has the above-mentioned structure, the light of the chip LED can be guided in any direction by changing the shape of the light guide. Therefore, there is no need to adjust the irradiation direction of light by combining the board on which the light emitter is mounted and the control board for controlling the light emitter as in the conventional case, and the light emitter (chip LED) and the control unit are provided on one substrate. Can be installed.

As a result, the number of parts can be reduced, and further, there is no positional deviation due to the combination of two substrates, and workability and reliability can be improved.

Further, when a plurality of chip LEDs are used, the arrangement can be made in a zigzag pattern to reduce the size.

Further, since the surface mount type chip LED is used, wire bonding is required, and there is no defect such as wire breakage and high reliability can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a schematic structure of an LED light emitting device according to this embodiment, and FIG. 2 is a vertical sectional view of the LED light emitting device.

As shown in FIGS. 1 and 2, the LED light-emitting device of this embodiment has a surface mount chip LED 2 on a substrate 1.
And a case 3 made of white resin having a light-shielding property is arranged so as to cover the chip LED 2. Inside the case 3, there is provided a light guide 4 made of a transparent resin that guides the light L from the chip LED 2 to the outside.

In practice, a plurality of light guides 4 arranged in parallel
The white resin case 3 having a light shielding property is formed by integrally molding the periphery of the.

Although not shown in the drawing, the chip L
A driver IC that controls the ED 2 is provided on an extension of the substrate 1.

As described above, the LED light-emitting device of the present invention has a structure in which the light from the chip LED 2 is guided to the outside by the light guide 4, so that the irradiation direction of the light is set to an arbitrary direction as necessary. It is not necessary to set the irradiation direction of light by combining the two boards, the chip mounting board and the control board, unlike the conventional case.

Therefore, a flexible board or the like for connecting the two boards is not required, the number of parts can be reduced, and there is no displacement during connection of the two boards, and workability and reliability can be improved.

Further, conventionally, LED chips are used and wire bonding is indispensable. However, in the present embodiment, since the surface mount type chip LED 2 is used, wire bonding is not necessary and wire bonding is performed. Problems such as wire breakage and connection failure due to the above can be solved, and reliability can be further improved.

3 and 4 are views for explaining an LED light emitting device according to another embodiment of the present invention, FIG. 3 is a plan view for explaining the arrangement of chip LEDs, and FIG. FIG. 4B is a plan view for explaining the arrangement method of the case mounted on the chip LED, and FIG. 4B is a sectional view taken along the line AA ′ of FIG.

The LED light emitting device according to the present embodiment is an LED
This embodiment is the same as the embodiment shown in FIGS. 1 and 2 in that a case having a light guide for guiding the light from the chip to the outside is used, but the arrangement method of the chip LEDs is different.

Chip LED of the LED light-emitting device of this embodiment
As shown in FIG. 3, the Nos. 2 are not arranged in one line but are arranged in two staggered lines. With this configuration, the pitch width of the adjacent chip LEDs 2 can be narrowed, and the LED light emitting device can be downsized.

Specifically, for example, when the chip LEDs 2 having a size of 1.6 mm square are used to form a 1 mm pitch, the chips are arranged on the printed circuit board as shown in FIG. 3 to 2 from 1st row to 2nd row
Arrange them at a pitch of 2 mm in a shifted form. Figure 4
As shown in (a) and (b), a reflection case 3'molded of a light-shielding white resin provided with a light guide 4'molded of a transparent resin is attached, and light from each chip LED 2 is printed. The light is irradiated in the direction parallel to the plane.

In the figure, 5 is an exit of the light guide 4 ', which is a light irradiation port.

By the above method, a chip L of 1.6 mm square
A 1 mm pitch LED array can be constructed using the ED2. In addition, by using three or more rows, it is possible to realize various kinds of pitches. Furthermore, using a double-sided board, the chip L
Arranging the ED2 on the front surface and the back surface can be similarly realized.

As described above, since the present invention uses the chip LED, it can be mounted on the board at the same time as other chip parts, and the workability is good and the cost can be kept low. There is no need to separate into two.

Further, the chip LEDs having a large shape can be arranged in a low pitch by alternately arranging a plurality of columns. As described above, it is possible to provide a low-pitch LED light emitting device that is low in cost and has good workability.

[0030]

As described above, according to the present invention, the workability is high, and the cost is low and the size is high.
An ED light emitting device can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic structure of an LED light emitting device according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of an LED light emitting device according to an embodiment of the present invention.

FIG. 3 is a plan view showing a chip LED arrangement of an LED light emitting device according to another embodiment of the present invention.

FIG. 4A is a plan view for explaining a case arrangement of an LED light emitting device according to another embodiment of the present invention, and FIG. 4B is a sectional view taken along line AA ′ of FIG.

FIG. 5 is a perspective view of a conventional LED chip mounting substrate.

6 is a cross-sectional view showing a state in which the LED chip mounting board of FIG. 6 is attached to a control board.

[Explanation of symbols]

 1 substrate 2 chip LED 3 light shielding case 4 light guide

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 33/00 N 7514-4M

Claims (2)

[Claims] 1. A surface-mounted chip L mounted on a substrate.
An ED and a light-shielding case provided on the substrate so as to cover the chip LED are provided, and a light guide body that guides light from the chip LED to the outside of the case is provided inside the light-shielding case. A light-emitting device characterized by the above. 2. The light emitting device according to claim 1, wherein a plurality of the chip LEDs are arranged in a zigzag pattern.