JPH05243777A - Electromagnetic shield structure for information equipment - Google Patents

Abstract

PURPOSE:To stabilize impedance of an enclosure and prevent noise generated in an equipment from being leaked externally. CONSTITUTION:The title equipment consists of cabinets 2, 4, and 8 mounting a keyboard 3 and covering an information processing device which contains a circuit board for mounting electronic parts such as a CPU 12, a chassis 15 for fixing the information processing device to the cabinets, wherein the chassis is formed of a conductive material and a conductive surface is formed on the inner surface of the cabinets. Furthermore, an integrated conductive member 32 which consists of a plurality of tongue pieces 33, a part 36 to be fixed to the chassis, and a part 34 for connecting the plurality of tongue pieces and the fixing part is provided in order to mechanically conduct the cabinets, the circuit substrate, and the chassis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing structure of an information device containing an information processing device, and more particularly to an electromagnetic shield structure for preventing leakage of electromagnetic waves generated inside the housing.

[0002]

2. Description of the Related Art In recent years, in the field of information equipment including personal computers and word processors, miniaturization is rapidly progressing, and its development is remarkable. Even if one computer is taken, miniaturization is rapidly progressing from a laptop computer to a notebook computer recently. Behind that, in addition to high density of memory, downsizing of electric parts, liquid crystal of a display device, and the like, plasticization of a cabinet which is a case can be raised. By the way, when the housing is made of a plastic material in this way, a noise problem occurs due to electromagnetic waves generated inside the housing. For this reason, designers are often worried about EMC (electromagnetic compatibility) measures.

As an example of the small information device as described above,
The one described in Japanese Utility Model Laid-Open No. 63-53119 can be mentioned, and its structural example will be described with reference to FIG. FIG. 4 is an external perspective view of a laptop computer that has been commonly used in recent years. The laptop computer 1 includes a lower cabinet 2 having a built-in information processing device including electronic components including a CPU and a circuit board (not shown), and an upper front cabinet 4 having a keyboard 3 as information input means. And a display cabinet 6 in which a liquid crystal display unit 5 for displaying the input information is mounted, and an upper rear cabinet 8 having a mounting portion 7 for mounting the display cabinet 6.

FIG. 5 is a sectional view showing the internal structure of the laptop computer 1. The same members as those in FIG. 4 are denoted by the same reference numerals and the description thereof is omitted. The lower cabinet 2 is provided with a screw fastening portion 11. Inside the lower cabinet 2, a CPU board 14 on which a CPU 12 and other electronic components 13 such as an input / output circuit are mounted, a chassis 15 made of a metal member for fixing the upper rear cabinet 8 or a power supply section 16 is provided. It is built in.
The CPU board 14 and the chassis 15 are fixed to the screw fastening portion 11 of the lower cabinet 2 with screws 17, and the upper rear cabinet 8 is fixed to the chassis 15 with screws 17. Further, the upper front cabinet 4 holds a keyboard board 18 for processing signals input from the keyboard 3, and the upper front cabinet 4 is fixed to the lower cabinet 2 and the upper rear cabinet 8. The above cabinets are generally fixed by fitting.
Of course, the keyboard board 18 and the CPU board 14 are electrically connected to each other, though not shown. The display cabinet 6 is tilted above the keyboard 3 as a lid when not in use, with the mounting portion 7 provided in the upper rear cabinet 8 as the center of rotation.

In the case of a small information device such as the laptop computer 1, each of the above cabinets 2, 4, 6,
Since 8 is often made of a plastic material, at least the inner surfaces of the lower cabinet 2, the upper front cabinet 4, and the upper rear cabinet 8 have a conductive surface to prevent noise generated by the device from leaking to the outside. 1
9, 20, and 21 are formed. This conductive surface is generally formed by plating, painting, vapor deposition, or the like. The conductive surfaces 19, 20, 21 are connected to each other at the fitting portions of the cabinets 2, 4, 8.

Recently, in order to stabilize the fitted state between cabinets and further enhance the shielding effect, the conductive material shown in FIG. 6 is often used. FIG. 6 shows a perspective view of the conductive material. The conducting member 25 is formed of a rigid body portion 26, a spring portion 27 and a mounting portion 28, and is fixed to the chassis 15 together with the upper rear cabinet 8 by screws 17 as shown in FIG. Then, the spring portion 27 is pressed against the upper front cabinet 4, and the lower cabinet 2
The conducting surface 19 is connected to the conducting surface 20 of the upper front cabinet 4 through the chassis 15.

When the laptop computer 1 is used in the above-described structure, first the display cabinet 6 is lifted around the mounting portion 7 as a rotation center as shown in FIG. Turn on the power and operate the necessary keys on the keyboard 3. The signal input by this is sent to the CP via the keyboard board 18.
The signal that has been processed by the U board 14 and that has been input is the CPU 1
It is designed to be stored in memory 2 or output and displayed on the liquid crystal display unit 5.

[0008]

However, according to the former structure in which the conducting surface is formed on the inner surface of each cabinet, although the conducting surface is formed, the connection of the conducting surfaces between the cabinets is different. Since the electrical connection is established only in the fitting portion of the cabinet, the impedance of the cabinet formed by the cabinets varies depending on the assembled state. This phenomenon becomes unstable especially in the fitting part of the cabinets. Therefore, there is a problem that the noise level generated by the device is not stable and large noise is generated.

If a conductive material is used like the latter,
Although the mating condition between cabinets is stable and the shielding effect is slightly improved, such a single-piece configuration is generally a so-called cut-and-try method that is incorporated while measuring the noise level at the time of assembly. Will be assembled. For this reason, it takes a lot of time to take EMC countermeasures, and it is very difficult to include EMC countermeasures at the beginning of designing the housing.

The present invention has been made to solve the above problems, and provides a structure for further stabilizing the impedance of the housing and preventing the noise generated by the device from leaking to the outside. The purpose is to

[0011]

An electromagnetic shield structure for an information device according to a first aspect of the present invention covers a circuit board on which electronic components such as a CPU are mounted, an information processing apparatus including the circuit board, and a keyboard. A cabinet structure for information equipment, which includes a cabinet for mounting information processing equipment, and a chassis for fixing an information processing device to the cabinet. The chassis is made of a conductive material, and a conductive surface is formed on the inner surface of the cabinet. A cabinet, a circuit board, and a chassis, having a plurality of tongues, a screw-fastening portion for attaching to the chassis, and an integral conducting member composed of a connecting portion connecting the plurality of tongues and the screw-fastening portion, It is characterized in that conduction is made by this conduction member.

According to a second aspect of the electromagnetic shield mechanism of the information equipment of the present invention, the conductive member is formed to have a length substantially equal to the inner surface width of the cabinet, and the tongue piece is U-shaped or V-shaped. It is characterized by having and having an elastic member.

[0013]

In the housing structure for information equipment according to the present invention, the conductive surface is formed on the inner surface of the cabinet, and the circuit board, the metal chassis for fixing the circuit board, and the cabinet are connected to each other by connecting a plurality of tongue pieces. Since it is conducted by the integrated type conducting member connected by the cable, the conduction can be achieved in the shortest distance, and the impedance can be reduced and stabilized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 shows an exploded perspective view of a main part of a laptop computer showing an embodiment of the present invention, and FIG. 2 shows a state in which an integral conducting member having a plurality of tongues is incorporated in the laptop computer of FIG. It is a principal part exploded perspective view shown. Further, FIG. 3 is an enlarged cross-sectional view of a main part of a portion surrounded by a broken line ellipse shown in FIG. 5, showing a state in which the integrated conduction member of the present invention is incorporated. In the figure, the same parts as those used in FIGS. 4 to 6 are designated by the same reference numerals to simplify the description. A laptop computer 31 using the present invention includes a CPU board 14 on which a CPU 12 and the like are mounted.
Lower cabinet 2 with built-in information processing device including
And an upper front cabinet 4 having a keyboard 3 mounted thereon, a display cabinet 6 having a liquid crystal display unit 5 for displaying information, and an upper rear cabinet 8 having a mounting portion 7 for mounting the display cabinet 6. It is the same as before. Further, the lower cabinet 2 has a screwing portion 11 formed therein, a CPU board 14 on which a CPU 12 and other electronic components 13 such as an input / output circuit are mounted, a chassis 15 made of a metal member, or a power supply. The part 16 and the like are built in. In addition, since each of the cabinets 2, 4, 6, and 8 of the laptop computer 31 is made of a plastic material, at least the inner surfaces of the lower cabinet 2, the upper front cabinet 4, and the upper rear cabinet 8 are
In order to prevent noise generated by the device from leaking to the outside, conductive surfaces 19, 20 and 21 are respectively formed as in the conventional case.

A feature of the present invention is that it has a conducting member 32 made of a conductive material as shown in FIG. In this conducting member 32, for example, one plate material is bent to form a plurality of tongue pieces 33, and the plurality of tongue pieces 33 are integrally formed by a connecting portion 34. The tongue piece 33
As shown in FIG. 3, is composed of an elastic spring portion 35 that is bent in a U shape or a V shape, and a fixing portion 36 that is bent and formed on the side opposite to the tongue piece 33 with respect to the connection portion 34. ing. Then, the fixing portion 36 is screwed and fixed to the chassis 15 with a plurality of screws 37 as described later.

As the conductive member 32, for example, a phosphor bronze or stainless spring material can be used.

Next, the assembly structure will be described with reference to FIGS. As shown in FIG. 3, the CPU board 14 and the chassis 15 are fixed to the screw fastening portion 11 of the lower cabinet 2 by screws 17 in the vicinity of the center of the laptop computer 31. At the top of this chassis 15,
The upper rear cabinet 8 and the above-mentioned conducting member 32 are fixed by screws 17. The upper front cabinet 4 is fixed by the mounting hole 8a of the upper rear cabinet 8 and the fitting portion of the lower cabinet 2, and at the same time, the plurality of tongue pieces 33 of the conducting member 32 are attached to the conducting surface 20 of the upper front cabinet 4. The spring portions 35 are in pressure contact with each other.

As a result, a conduction path is formed from the conduction surface 19 of the lower cabinet 2 to the chassis 15 via the CPU board 14 or the screw 17, and then to the upper rear cabinet 8.
Of the upper front cabinet 4 from the plurality of tongue pieces 33 to the conductive member 32 via the conductive surface 21 of the upper surface and the screw 37.
Has been formed. Of course, the fitting paths of the cabinets 2, 4, and 8 also have a structure in which the conduction paths are connected. As described above, the cabinet, the circuit board, and the chassis are electrically connected to each other, and the plurality of tongue pieces 33 of the conductive member 32 are integrally formed by the connecting portion 34. Can be the shortest distance. Therefore, the impedance between the respective members can be reduced and stabilized, and the noise generated by the device can be prevented from leaking to the outside as much as possible. Furthermore, the chassis 15 is formed in the cabinet formed by the cabinet.
Since it is divided into two in the vicinity of, each space is isolated and the mutual influence of electromagnetic waves is reduced. Also in the experimental example, as the noise level seen in the VCCI standard, the frequency characteristic is 150 MHz between the case where the conductive member 32 having the plurality of tongue pieces 33 integrally formed by the connection portion 34 is interposed and the case where it is not. Therefore, the noise level could be improved by 5.5 dB, which was a good result.

[0019]

As is apparent from the above description, according to the electromagnetic shield structure for information equipment of the present invention, the plurality of tongue pieces 3 are provided.
3 is integrally formed by the connecting portion 34, and the component parts of the device are mechanically connected to each other, so that the conductive path has the shortest distance, and the case impedance can be reduced and stabilized. It is possible to effectively prevent the electromagnetic wave leakage. In addition, since it becomes possible to incorporate EMC measures from the beginning of designing the housing, it is possible to greatly shorten the design period, and the effect is great.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of essential parts of a laptop computer showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of essential parts showing a state in which an integral type conductive member in which a plurality of tongue pieces are connected by a connecting portion is incorporated in the laptop computer showing the embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of an essential part of a portion surrounded by an ellipse shown in FIG. 5, showing a state in which an integrated tongue according to an embodiment of the present invention is incorporated.

FIG. 4 is an external perspective view of a commonly used laptop computer.

FIG. 5 is a cross-sectional view showing the internal structure of a conventional laptop computer.

FIG. 6 is a perspective view of a conventional conductive material.

[Explanation of symbols]

 1,31 Laptop computer 2 Lower cabinet 3 Keyboard 4 Upper front cabinet 6 Display cabinet 8 Upper rear cabinet 12 CPU 14 CPU board 15 Chassis 19, 20, 21 Conducting surface 32 Conducting member 33 Tongue piece 34 Connecting portion 35 Spring portion 36 Fixed part

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshihisa Tamura 2-18 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Inventor Satoshi Ishikawa 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. Within the corporation

Claims (2)

[Claims] 1. A circuit board on which an electronic component including a CPU as information processing means is mounted, a cabinet that covers the information processing apparatus including the circuit board and includes information input means, and the information processing apparatus, In a housing structure of an information device including a chassis fixed to a cabinet, the chassis is formed of a conductive material, and a conductive surface is formed on an inner surface of the cabinet, and a plurality of tongue pieces and screw fastening portions for mounting to the chassis are provided. And a conducting member integrally formed with a connecting portion continuous with the plurality of tongue pieces and the screwing portion, and the cabinet, the circuit board, and the chassis are electrically conducted by the conducting member. The electromagnetic shield structure of the information equipment that features. 2. The conductive member is in contact with the inner surface of the cabinet, and is constituted by an elastic member in which the tongue piece is formed in a U shape or a V shape. Electromagnetic shield structure for information equipment.