JP2001168376A - Infrared data communication module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared data communication module which is made more small-sized by shortening the distance between a light emitting element and a light receiving element. SOLUTION: On one surface of a circuit board 11, the light emitting element 12 composed of a fast infrared LED and the light receiving element 13 composed of a photodiode are provided side by side and the light emitting element 12 and light receiving element 13 is sealed in one body with light-transmissive resin 16 to form a different type hemispherical lens 14 having its light emission side and light reception side close to each other, thus shortening the distance between the light emitting element and light receiving element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an infrared data communication module used for electronic equipment such as a personal computer, a printer, a PDA, a facsimile, a pager and a mobile phone.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for miniaturization of infrared communication modules in portable devices such as notebook personal computers, PDAs, and mobile phones equipped with an optical communication function. The light emitting element consisting of LED, the light receiving element consisting of photodiode, the circuit part consisting of IC with built-in amplifier, drive circuit, etc. is directly die-bonded and wire-bonded to the lead frame, and the lens is resin molded with visible light cut epoxy resin. , A transmitting unit and a receiving unit
A packaged infrared data communication module has been developed.

Conventionally, an infrared data communication module described in Japanese Patent Application Laid-Open No. Hei 10-233471 has been known. The infrared data communication module described in Japanese Patent Application Laid-Open No. Hei 10-233471 uses a circuit board with through holes, and allows electronic components to be mounted on both the front and back sides of the circuit board. This Japanese Patent Laid-Open No. 10
FIG. 8 shows a conventional infrared data communication module described in JP-A-233471.

The infrared data communication module shown in FIG. 8 has a light emitting element 52 and a light receiving element 5 on the upper surface side of a circuit board 51.
3 are connected to an IC chip 54 having a circuit section in which a high-speed amplifier, a drive circuit and the like are incorporated on the lower surface side of the circuit board 51. On the upper surfaces of the light emitting element 52 and the light receiving element 53, hemispherical lens portions 56a and 56b are respectively formed by a transparent resin 55,
It has functions of irradiating and condensing infrared light while protecting both elements.

[0005]

The infrared data communication module shown in FIG. 8 has a light emitting element 52 and a light receiving element 53.
, Each having a separate hemispherical lens 56a and 56
Since b is provided, it is a limit to minimize the distance between the ends of the hemispherical lenses 56a and 56b even if the infrared data communication module is to be downsized.

Accordingly, the present invention provides an infrared data communication module which is further downsized by shortening the distance between the light emitting element and the light receiving element.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an infrared data communication module having a light emitting element and a light receiving element juxtaposed on one surface of a substrate. A light emitting / receiving lens is formed close to the light receiving side, so that the distance between the light emitting element and the light receiving element is reduced.

As a result, the distance between the light-emitting element and the light-receiving element can be reduced as much as possible without interfering with each other, and a further downsized infrared data communication module can be obtained.

[0009]

The invention according to claim 1 is an infrared data communication module having a light emitting element and a light receiving element juxtaposed on one surface of a substrate, wherein the light emitting element and the light receiving element are integrally resin-sealed. An infrared data communication module characterized by forming a light emitting / receiving lens in which the light emitting side and the light receiving side are close to each other, and the distance between the light emitting element and the light receiving element is as short as possible without interfering with each other. It is possible to do.

According to a second aspect of the present invention, the light emitting and receiving lens has a shape in which the light receiving element and the light receiving element are connected by a line that is in contact with an imaginary lens curved surface designed separately for the light emitting element and the light receiving element. This is an infrared data communication module, in which the curved surface of the light receiving / emitting lens can be made smooth.

According to a third aspect of the present invention, in the infrared data communication module according to the second aspect, the line tangent to the curved surface of the lens is a straight line or a curved line. A tied and smooth shape can be obtained.

According to a fourth aspect of the present invention, the lens surface of the light emitting / receiving lens which intersects the optical axis of each of the light emitting element and the light receiving element is locally parallel to the substrate. An infrared data communication module according to any one of the above, wherein the light emitting element and the light receiving element can have their optical axes parallel.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a front sectional view of an infrared data communication module (hereinafter, referred to as "module") in a first embodiment, and FIG. 2 is a side sectional view thereof.

As shown in FIGS. 1 and 2, the module according to the first embodiment includes a light-emitting element 12 composed of a high-speed infrared LED and a photo-detector on one surface of a circuit board 11 (the upper surface in the example of FIG. 1). A light receiving element 13 composed of a diode is arranged in parallel. On the upper surface of the light emitting element 12 and the light receiving element 13, a modified hemispherical lens 14 is formed as a light receiving / emitting lens whose light emitting side and light receiving side are close to each other. I have.

The circuit board 11 has an insulating resin substrate 1 made of glass epoxy resin or the like having a substantially rectangular flat surface.
A conductive pattern (not shown) is formed on the upper and lower surfaces of 1a, and is electrically connected via through-hole electrodes of through-holes 11b formed on the resin substrate 11a. The circuit board 11 is a glass epoxy board, but may be an alumina ceramic board, a plastic film of polyester or polyimide, or the like.

The light emitting element 12 and the light receiving element 13 are connected to the conductive pattern on the upper surface side of the circuit board 11 by die bonding and wire bonding, respectively. In addition, an IC chip 15 having a circuit section in which a high-speed amplifier, a drive circuit, and the like are incorporated is die-bonded and wire-bonded to the conductive pattern on the lower surface side of the circuit board 11, and is connected via a through-hole electrode of the through-hole 11b. ing. The IC chip 15 may be mounted face down on the circuit board 11 without wire bonding.

The light-emitting element 12 and the light-receiving element 13 are resin-sealed with an epoxy-based translucent resin 16 containing a visible-light-cutting agent. Irradiating and condensing functions, and protect both elements. In addition, an I-mount mounted on the lower surface of the circuit board 11 by the translucent resin 16 is used.
The C chip 15 is sealed with a resin. The sealing of the IC chip 15 is not limited to the translucent resin 16, but may be performed with another thermosetting resin.

The modified hemispherical lens 14 is obtained by integrally sealing the light emitting element 12 and the light receiving element 13 with a translucent resin 16 as shown in FIG. The atypical hemispherical lens 14 is an imaginary hemispherical lens 1 shown by a broken line in FIG.
4a and 14b are combined. The imaginary hemispherical lenses 14a and 14b are imaginary hemispherical lenses in which lenses are separately designed for the light emitting element 12 and the light receiving element 13 as in the related art. The imaginary hemispherical lens 14 a is arranged such that its optical axis overlaps the center of the light emitting element 12. Similarly, the fictitious hemispherical lens 14b
Are arranged such that their optical axes overlap the center of the light receiving element 13. Also, the imaginary hemispherical lenses 14a, 14b
Have the same radius.

Such imaginary hemispherical lenses 14a, 14
b denotes the light emitting element 12 and the light receiving element 13 as shown in FIG.
Are mounted in close proximity to each other so that two imaginary hemispherical lenses 1
The spherical surfaces of 4a and 14b overlap. The atypical hemispherical lens 14 has a straight line that is tangent to the curved surfaces of the imaginary hemispherical lens 14a and the imaginary hemispherical lens 14b, that is, a shape connected by a tangent, and the tangent is a straight line parallel to the circuit board 11. . In this case, the light emitting element 12 side,
The spherical surfaces of the imaginary hemispherical lenses 14a and 14b that intersect the optical axis on both the light receiving element 13 side are locally parallel to the circuit board 11.

In the module having the above structure, the light emitting element 12 and the light receiving element 13 are integrally resin-sealed to form a modified hemispherical lens 14 in which the light emitting side of the light emitting element 12 and the light receiving side of the light receiving element 13 are close to each other. Thus, the distance between the light emitting element 12 and the light receiving element 13 can be reduced as much as possible without interfering with each other, and a further downsized module can be obtained.

(Embodiment 2) FIG. 3 is a front sectional view of a module according to a second embodiment.

As shown in FIG. 3, the module according to the second embodiment has the first shape except for the shape of the atypical hemispherical lens 17.
The configuration is the same as that of the embodiment. Atypical hemispherical lens 17
Are imaginary hemispherical lenses 17a and 17b similar to those of the first embodiment having different radii indicated by broken lines in FIG.
Are combined. Fictitious hemispherical lens 17a,
17b is arranged such that its optical axis overlaps the center of the light emitting element 12 and the center of the light receiving element 13, respectively.
The radius of the fictitious hemispherical lens 17a on the second side is
It is larger than the radius of the imaginary hemispherical lens 17b on the side.

Such an imaginary hemispherical lens 17a, 17
b represents the light emitting element 12 and the light receiving element 13 as shown in FIG.
Are mounted in close proximity to each other so that two imaginary hemispherical lenses 1
The spherical surfaces 7a and 17b overlap. The modified hemispherical lens 17 has a shape that is smoothly connected by a curve that is in contact with the curved surfaces of the imaginary hemispherical lens 17a and the imaginary hemispherical lens 17b.

In the module according to the second embodiment, similarly to the first embodiment, the distance between the light emitting element 12 and the light receiving element 13 can be reduced as much as possible without interfering with each other. Thus, a more miniaturized module can be obtained.

In the module according to the second embodiment, since the optical axes on the light emitting element 12 side and the light receiving element 13 side are directly in front, both the light emitting element 12 side and the light receiving element 13 cross the optical axis. Atypical hemispherical lens 1
The spherical surface 7 is locally parallel to the circuit board 11.
Therefore, the light emitting element 12 side and the light receiving element 13 side
The two optical axes are parallel to each other, and even if the distance between the two modules arranged facing each other is large,
Both transmission and reception are performed favorably in the same direction.

On the other hand, the example shown in FIG. 4 is a module in which the atypical hemispherical lens 18 is a straight line that is in contact with the curved surfaces of the imaginary hemispherical lenses 17a and 17b, that is, a tangent line. This irregular hemispherical lens 1
The tangents forming 8 are not parallel to the circuit board 11 but have an inclination. Also, since the radius of the imaginary hemispherical lens 17a on the light emitting element 12 side is larger than the radius of the imaginary hemispherical lens 17b on the light receiving element 13 side, the light emitting element 12
Although the optical axis on the side faces directly in front, the optical axis on the light receiving element 13 side has a slight inclination. Therefore, the light emitting element 12
The two optical axes on the side and the light receiving element 13 side are not parallel,
When the distance between the two modules arranged opposite to each other is large, transmission and reception are not performed in the same direction,
There is a possibility that data transmission / reception becomes impossible.

Therefore, like the module according to the second embodiment shown in FIG. 3, the modified hemispherical lens 17 intersecting the respective optical axes of the light emitting element 12 and the light receiving element 13.
It is necessary to make the lens surface locally parallel to the circuit board 11 in order to perform good transmission and reception even when the distance between the two modules arranged facing each other is large.

[0029]

EXAMPLES (Example 1) The directional characteristics of the module according to the first embodiment will be described.

In the module according to the first embodiment shown in FIGS. 1 and 2, the optical axes of the imaginary hemispherical lenses 14a and 14b are arranged so as to overlap the centers of the light emitting element 12 and the light receiving element 13, respectively, as described above. The spherical surface of the modified hemispherical lens 14, which crosses the optical axis on both the light emitting element 12 side and the light receiving element 13 side, is locally parallel to the circuit board 11. Therefore, the light emitting element 1
The two optical axes on the second side and the light receiving element 13 side are parallel to each other.

FIG. 5 shows the directional characteristics of the module according to the first embodiment during light emission. The directional characteristics of the module according to the first embodiment during light emission are as follows:
As shown in FIG. 5, although it protrudes toward the light receiving element 13, it has the strongest directivity with respect to the front of the light emitting element 12, and also has a smooth spreading directional characteristic as a whole.

Therefore, in the module according to the first embodiment, even if there is a slight shift not only in front of the atypical hemispherical lens 14 with respect to the facing module (communication partner), light easily enters the communication partner, Communication is possible even if the positional relationship with the communication partner is roughly set. The directional characteristics at the time of light reception follow this.

Here, for comparison with the module of the first embodiment, FIG. 6 is a front sectional view of a module according to another embodiment, and FIG. 7 shows the directivity characteristics at the time of light emission.

The module shown in FIG. 6 has substantially the same configuration as the module in the first embodiment, but the modified hemispherical lens 19 is a lens in which the spherical surfaces of the imaginary hemispherical lenses 14a and 14b are simply overlapped. It is a shape.

As shown in FIG. 7, the directivity characteristic of such a module at the time of light emission shows a broad characteristic as in the module of the first embodiment shown in FIG.
An irregular directional characteristic having a valley between the second side and the light receiving element 13 side is obtained. Therefore, it is difficult to use the light emitting element 12 in the same manner as the module in the first embodiment.
Use directly in front is possible without any problems.

(Example 2) The directional characteristics of the module according to the second embodiment will be described.

In the module according to the second embodiment shown in FIG. 3, the irregular hemispherical lens 17 is used as described above.
Are the imaginary hemispherical lens 17a and the imaginary hemispherical lens 1
7b is a shape smoothly connected by a curve tangent to the curved surface of FIG. The optical axes on the light emitting element 12 side and the light receiving element 13 side are directly in front, and the spherical surface of the atypical hemispherical lens 17 that intersects the optical axis on both the light emitting element 12 side and the light receiving element 13 side is locally located on the circuit board 11. Is parallel to for that reason,
The two optical axes on the light emitting element 12 side and the light receiving element 13 side are
Be parallel to each other.

Therefore, the directivity characteristics of the module at the time of light emission and light reception at the time of light emission and light reception are the same as in the first embodiment. It shows strong and directional characteristics with a smooth spread as a whole.

[0039]

According to the present invention, the light emitting element and the light receiving element are integrally sealed with a resin to form a light receiving and emitting lens, so that the distance between the light emitting element and the light receiving element is infinitely small so as not to interfere with each other. The infrared data communication module can be shortened, and a further downsized infrared data communication module can be obtained.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an infrared data communication module according to a first embodiment;

FIG. 2 is a side sectional view of FIG. 1;

FIG. 3 is a front sectional view of an infrared data communication module according to a second embodiment;

FIG. 4 is a front sectional view of an infrared data communication module showing another embodiment.

FIG. 5 is a diagram illustrating a directional characteristic of the infrared data communication module according to the first embodiment when light is emitted.

FIG. 6 is a front sectional view of a module showing another embodiment.

FIG. 7 is a diagram showing the directional characteristics of the module of FIG. 6 during light emission.

FIG. 8 is a front sectional view of a conventional infrared data communication module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Circuit board 11a Resin board 11b Through hole 12 Light emitting element 13 Light receiving element 14, 17, 18, 19 Irregular hemispherical lens 15 IC chip 16 Translucent resin

Claims (4)

[Claims] 1. An infrared data communication module having a light emitting element and a light receiving element juxtaposed on one surface of a substrate, wherein the light emitting element and the light receiving element are integrally resin-sealed so that the light emitting side and the light receiving side are close to each other. An infrared data communication module comprising a light emitting lens. 2. The infrared data communication module according to claim 1, wherein the light receiving and emitting lens is formed by connecting a line in contact with an imaginary lens curved surface separately designed for the light emitting element and the light receiving element. 3. The infrared data communication module according to claim 2, wherein the line in contact with the curved surface of the lens is a straight line or a curved line. 4. The infrared data according to claim 1, wherein a lens surface of the light receiving / emitting lens that intersects an optical axis of each of the light emitting element and the light receiving element is locally parallel to the substrate. Communication module.