JPH0240235B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a technology for preventing malfunction, damage, etc. of electronic equipment whose housing is made of dielectric material such as plastic due to discharge of electrical charges. In particular, the present invention relates to an electrostatic breakdown voltage structure that prevents the above-mentioned malfunctions, damage, etc. by increasing the electrostatic breakdown voltage through a unique structure.

(Technical Background and Problems) Recently, the housings of electronic devices are increasingly made of plastic for reasons of aesthetics and cost. In addition, reflecting the miniaturization and higher performance of electronic devices, the mounting density of electronic components housed inside the housing is increasing, and printed boards for mounting and wiring electronic components such as semiconductor components are installed near the inner surface of the housing. This is becoming more and more common.

In addition, with the recent progress in air conditioning in buildings, electronic devices are being used in dry environments, and floors are now covered with things that can generate static electricity, such as carpets. In such an environment, the casing is charged to a high voltage because it is a dielectric material (insulator). On the other hand, as mentioned above, because the printed circuit board is installed close to the inner surface of the housing, the discharge voltage of static charge is low (about 3kV at most in a normal structure). Electrostatic charge can easily be discharged between the operator of the electronic device and the printed circuit board through the gap between the body, which not only causes discomfort to the operator, but also causes discomfort to the operator.
More importantly, there are problems in that electronic components mounted on the printed circuit board are destroyed and data stored in the semiconductor memory is damaged due to the discharge.

(Objective of the Invention) The present invention is proposed to solve the above-mentioned problems, and an object of the present invention is to obtain a housing structure that can increase the electrostatic withstand voltage.

(Summary of the Invention) For the above-mentioned purpose, the present invention has a structure in which the assembly connection surface between the casing and the structure that penetrates inside and outside of the casing and is fitted is folded back, so that the discharge path of the electrostatic charges is lengthened. In this way, high voltage resistance can be obtained.

(Embodiments of the Invention) The drawings are diagrams showing an example in which the present invention is implemented in a telephone set, in which FIG. 1 is a perspective view of a light guide structure of a visible display means, and FIG. 2 is a perspective view of a light guide structure shown in FIG. 1. FIG. 3 is a cross-sectional view showing the structure in which the light guide structure is fitted into the case; FIG. 4 is a perspective view of the structure shown in FIG. 3; 5 is a cross-sectional view illustrating the discharge path of static charge; FIG. 5 is a perspective view of the dial button structure; FIG. 6 is a perspective view of the dial button structure;
The figure is a perspective view of a housing portion in which the dial button structure shown in FIG. 5 is fitted, viewed from inside the housing, and FIG. 7 is a sectional view showing a structure in which the dial button structure is assembled into the housing. Incidentally, in each of the above perspective views, a portion is shown as a cutaway cross section so that the present invention can be easily understood.

The present invention is implemented in terms of a structure in which a structure is fitted into the casing of a telephone by penetrating inside and outside the casing of the telephone.

The embodiments shown in FIGS. 1 to 3 are embodiments in which the structure is a light guide structure for visual display.

As shown in FIG. 1, the light guide structure 1 is integrally molded from a translucent plastic material.
A box body 10 having a light guide body 101 in the center and forming a light emitting diode storage space A below it.
Further, on the upper surface of the box body 102, a wall body 103 is constructed to surround the light guide body 101 and form a groove space B around the light guide body 101.

On the other hand, as shown in FIG.
2, a through space C is formed through which the light guide body 101 of the light guide structure 1 is inserted, and around the through space C, a tip portion protrudes inward from the inner surface 202 of the telephone housing 2. A wall 203 having an elongated shape is formed, and a groove space D formed around the wall 203 of the inner surface 202 is formed to a width that allows the wall 103 of the light guide structure 1 to fit therein. has been done. The thickness of the wall body 203 is set to a size that allows it to fit into the groove space B formed in the light guide structure 1.

FIG. 3 shows a state in which the light guide structure 1 described above is fitted into the visible display portion of the telephone housing 2. As shown in FIG. Incidentally, FIG. 3 also shows a printed board 3 housed in the telephone housing 2 and a light emitting diode 4 mounted and wired on the printed board 3.

As shown in FIG. 3, the light guide structure 1 is
The light guide body 101 is inserted through the through space C of the telephone housing 2 and incorporated into the telephone housing 2. As a result, the wall 103 of the light guide assembly 1 fits into the groove space D of the telephone housing 2, and the wall 203 of the telephone housing 2 fits into the groove space B of the light guide assembly 1, respectively. Further, the light emitting diode 4 mounted and wired on the printed board 3 is located in the storage space A formed inside the box 101 of the light guide structure 1, and the light from the light emitting diode 4 is transmitted to the light guide structure 1. It passes through the light guide body and reaches the outer surface of the telephone body 2.

In the above structure, a discharge path for charges due to charging is formed as shown by a dashed line in FIG. 4. That is, when the finger 5 approaches the surface of the telephone housing 2 in a charged state, the discharge path slightly extends from the finger 5 to the assembly connecting surface between the light guide structure 1 and the telephone housing 2. A path is formed to reach the ground conductor (not shown) of the printed board 3 through the gap E thus formed. This is because air is more prone to discharge breakdown (becoming in a conductive state due to ionization) than dielectric materials (the material of the light guide structure 1 and the phone housing 2).

As described above, the structure in which the light guide structure 1 is fitted into the telephone housing 2 is a folded structure in which the wall bodies 103 and 203 configured respectively fit into the groove spaces D and E formed respectively. Therefore, the gap E interposed in the discharge path becomes longer than that in a simple connecting surface structure. That is, as the discharge path becomes longer, the discharge voltage of electrostatic charges due to charging becomes higher, and it becomes difficult for electrostatic charges to be discharged between the printed board 3 and, for example, a human body.

The embodiments shown in FIGS. 5 to 7 are embodiments in which the conductor attached to the telephone housing is a dial button structure.

As shown in FIG. 5, the dial button structure 6 is entirely made of an elastic rubber material, and a plurality of dial buttons 601 are interconnected at their hem portions, and the hem portion is formed into a thin skirt shape. A recovery bullet 602 for each dial button 601 is constructed, and a conductive rubber contact 603 is attached to the bottom surface of each dial button 601, and the above structure itself is well known.

In the above structure, the following structure is added to implement the present invention. That is, the connecting portion 6 that interconnects each dial button 601
A wall body 605 is constructed at the four side ends of 04 in the same direction as the vertical direction of the dial button 601.

On the other hand, as shown in FIG. 6, the dial mounting portion of the telephone housing 2 is provided from the outer surface 201 of the telephone housing 2, similar to the through space C (FIG. 2) of the light guide body 101 in the above embodiment. A through space F for each dial button 601 is formed by penetrating the inner surface 202, and a tip portion is formed on the four sides around this group of through spaces, similar to the wall body 203 (FIG. 2) in the above embodiment. A wall body 204 is configured to protrude and extend inward from the inner surface 202 of the telephone housing 2.

The state in which the dial button structure 6 described above is fitted into the dial mounting portion of the telephone housing 2 is the seventh state.
It is shown in the figure. Also in this Figure 7, the third
Similarly, each dial contact conductor (not shown) is printed, and a semiconductor element (LSI) such as a dial sender is printed.
A printed board 8 on which components 7 and the like are mounted and wired is also shown.

The four wall bodies 605 formed on the four sides of the dial button structure 6 have inner dimensions a and b between the two facing sides, which are the same as those of the four walls formed on the four sides of the dial mounting part of the telephone housing 2. 2 facing walls 204
The dial button structure 6 is set to have approximately the same external dimensions e and d between the two, and when assembled, as shown in FIG. In addition to being inserted through the through space F, the dial mounting portion of the telephone housing 2 is attached in such a manner that the connecting portion 604 and the walls 605 on its four ends enclose and cover the surrounding wall 204. The assembly connecting surface between the telephone housing 2 and the dial button structure 6 is formed by two walls 2.
Due to the surface contact structure between 04 and 605, it has a folded structure similar to the previous embodiment, and the same static charge discharge path as described above is lengthened to prevent static charge discharge between the printed board 8 and, for example, a human body. is less likely to occur.

The breakdown voltage obtained with the configuration of the present invention varies depending on the structural dimensions of each part, but a high breakdown voltage of about 15 to 20 kV can be easily obtained.

The above two embodiments are both examples in which the present invention is implemented in a telephone, but the present invention can be applied to the case of any electronic device that has electronic components that may be destroyed by electrostatic charge discharge. Can be performed on the body.

(Effect of the invention) As is clear from the detailed explanation above,
The present invention provides a wall body having a structure in which vertical surfaces are in surface contact with each other at each fitting portion where a housing and a structure incorporated therein are assembled together, so that the entire length of the gap created at the fitting portion is It has a long structure to lengthen the discharge path for static charges caused by charging.It is an extremely simple structure, and the discharge withstand voltage of static charges is dramatically improved, thus making electronic equipment less susceptible to discharge due to charging. The present invention has extremely significant effects, such as greatly reducing the risk of malfunctions or destruction of electronic components in electronic devices due to discharge due to charging.

[Brief explanation of drawings]

The drawings are all diagrams for explaining the embodiments of the present invention, and FIG. 1 is a perspective view of the light guide structure, FIG. 2 is a perspective view of the part where the light guide structure is attached to the casing, and FIG. 3 is a perspective view of the light guide structure attached to the casing. FIG. 4 is a cross-sectional view illustrating the discharge path of static charge, FIG. 5 is a perspective view of the dial button structure, and FIG. 6 is a cross-sectional view of the dial button structure mounting part of the housing. The perspective view and FIG. 7 are cross-sectional views of the dial button structure assembled into the housing. Main symbols: 1...Light guide structure, 103...Wall body, B...Groove space, 2...Telephone housing, 203, 20
4...Wall body, D...Groove space, 3, 8...Printed board, 6
...Dial button structure, 605...Wall body.

Claims (1)

[Claims] 1. In an electronic device case having a structure in which a structure made of a dielectric material is fitted into the case by penetrating the inside and outside of the case, the case and the structure are A wall structure is provided at each fitting portion where the two are assembled together, so that the charged and discharge path formed by the gap formed in the fitting portion is lengthened. Electrostatic pressure-resistant structure of the equipment case.