JPH114091A - Electromagnetic shielding case of portable telephone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable electromagnetic waves radiating from a portable telephone main body toward a human body to be attenuated by a method wherein a perforated metal plate formed through an electron beam perforating process is used as an electromagnetic shielding material corresponding to the speaker and microphone of the portable telephone. SOLUTION: Communication radio waves are radiated from the tip of an antenna 101 which is extended high above the operator's head for most of the time when a case 1 which contains a portable telephone is disposed near an operator's head in operation. Radiowaves leaking out of a telephone main body disposed near the operator's head are markedly attenuated by the case 1 which is so formed of electromagnetic shielding material mainly made of perforated stainless steel plate subjected to EBP processing as to constitute a so-called Faraday cage, so that radiowaves leaking to irradiate a human body are markedly lessened in dosage. By this setup, a shield case of this constitution can be markedly improved in electromagnetic shielding effect SE (db) to high-energy electromagnetic waves which radiate from a portable telephone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables an electromagnetic shield other than electromagnetic waves radiated from an antenna of a portable telephone to be radiated from a circuit in the portable telephone main body and leaked from the main body to the outside. The present invention relates to a storage case for a mobile phone.

[0002]

2. Description of the Related Art Cellular Phone [Simple Cellular Phone (PHS)]
It is known that in addition to the electromagnetic wave radiated from the tip of the antenna for the original communication, the electromagnetic wave is also radiated from a circuit in the main body and leaks from the main body. Although the effects of electromagnetic waves on the human body are not yet clear, there may be some undesirable effects. In particular, the speaker part of the body of the mobile phone, which is located relatively close to the antenna, usually has a plurality of relatively large holes for sound propagation, so the radiated electromagnetic waves from the internal circuit are not significantly attenuated. It may be radiated to the outside through the hole, and when talking for a long time, it is conceivable that the loudspeaker part in contact with the ear may continue to emit relatively strong electromagnetic waves during the call.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic shield for a portable telephone which advantageously attenuates the energy of electromagnetic waves which can be radiated from the body of the portable telephone (including the PHS) to a human body during a call. Is to provide a case.

[0004]

Means for Solving the Problems and Actions and Effects of the Invention According to the first aspect of the present invention, there is provided an electromagnetic shield case for a portable telephone, which is formed of an electromagnetic shield material and has an antenna portion. An electromagnetic shield case for a mobile phone except that the mobile phone can be housed therein, wherein at least a hole formed by an electron beam drilling process is used as an electromagnetic shield material at least for a portion corresponding to a speaker portion and a macrophone portion of the mobile phone. It is characterized by using a perforated metal plate.

[0005] Conventionally, punching metal as an electromagnetic shielding material is well known. Such an electromagnetic shielding effect SE of a metal plate in which a large number of holes are formed in a uniform distribution is not significantly affected by the opening ratio of the plate due to the large number of holes formed in the plate when the opening ratio of the plate is larger than a certain level. It is generally known that it is proportional to the thickness of the plate and inversely proportional to the diameter of the hole [for example, "Handbook for Noise Countermeasures" published by Nikkan Kogyo Shimbun.
(First Edition, August 30, 1994), p. 206]. From this, when the thickness of the plate is constant, decreasing the hole diameter and increasing the opening ratio of the plate by the holes is the same as maintaining the rigidity to a certain degree by keeping the plate thickness unchanged. As the aperture ratio increases, the sound transmission, transparency, air permeability, and lightness per unit area are each correspondingly improved, and the electromagnetic shielding effect SE is significantly increased with the decrease in the hole diameter. It is known that it can be increased and is advantageous. However, in punching (punching) processing,
Drilling a large number of small holes with the correct hole diameter and arrangement requires time and labor for processing, and accordingly, the hole diameter is 0.5 to 1 mm.
The degree was a practical limit. Therefore, in order to increase the electromagnetic shielding effect SE (dB), the thickness had to be increased, the weight was also increased, and it was difficult to use, and it was a victory.
On the other hand, electron beam perforation (Electron Beam Perf
oration, abbreviated as EBP), is a process in which an electron beam accelerated at a high speed by a voltage impinges on the surface of a workpiece, instantaneously heat-melts the impacted portion by high-density energy emitted from the electron beam, and almost instantaneously holes This method is advantageous in that a large number of small-diameter holes are formed in a metal plate or the like with an accurate hole diameter and arrangement. The range of the hole diameter that can be punched by this electron beam drilling (hereinafter, referred to as EBP) is 1 μm to 1 mm. In particular, the processing method is characterized by processing a hole having a diameter of 0.2 mm or less. The inventor has been interested in suppression of electromagnetic wave radiation from the mobile phone main body. For that purpose, the inventors focused on the usefulness of a mobile phone case formed by using an electromagnetic shielding material and having an electromagnetic shielding property. A large number of small holes of a predetermined diameter are formed according to a predetermined arrangement and pitch (accordingly, aperture ratio).
A metal plate of a predetermined thickness accurately provided with a metal plate can reduce the weight per unit area of the plate while maintaining a certain degree of rigidity, and can also improve sound signal propagation such as voice, air permeability and transparency, and besides electromagnetic Focusing on the fact that the shielding effect SE can be remarkably improved, and the above-described EBP processing is performed on at least a portion of the case made of the electronic shield material for the mobile phone, which includes a corresponding portion of the speaker and the microphone of the mobile phone. The present invention has been accomplished in view of the advantage of using a perforated metal plate having holes.

The electromagnetic shield case for a portable telephone according to the first aspect of the present invention includes a metal plate having a predetermined thickness on a portion corresponding to a speaker portion and a microphone portion of the portable telephone.
Small diameter hole by BP processing, preferably 0.2mm
A so-called Faraday cage is formed by using a perforated metal plate formed with a large number of holes having the following diameters at a predetermined arrangement and a predetermined pitch (according to an aperture ratio). Shielding effect SE for high energy electromagnetic waves that can be radiated from
(DB) can be greatly improved, so that the user can be at least relieved during a call, without deteriorating the sound propagation performance in the speaker section and the microphone section, and maintaining the required rigidity and light weight. Further, when the aperture ratio is increased, the transparency can be improved.

The arrangement of the holes in the perforated metal plate is advantageous in that the 60-degree staggered arrangement (see FIG. 1) can increase the aperture ratio under a smaller decrease in the strength and rigidity of the plate. (The same as the so-called 45-degree staggered arrangement). The ratio (t / d) of the thickness (t) of the perforated metal plate to the diameter (d) of the hole (however, the hole perpendicular to the plate) is 2.5.
The electromagnetic shielding effect SE of the perforated metal plate is determined as above.
Of about 80 dB or more is preferable.
Further, it is preferable that the aperture ratio of the perforated metal plate by the holes is 20% or more, since not only the sound transmission property but also the see-through property is considerably provided, and the weight per unit area is further reduced. The larger the aperture ratio is, the more advantageous it is.
%, The rigidity and strength of the forming material (constituent material) of the electromagnetic shield case may be insufficient depending on the plate thickness and the material. Consideration should be given to increasing the aperture ratio only in the portion, increasing the thickness of the forming material, or changing the material. Also, the direction of the many holes of the perforated metal plate formed by the EBP process is not perpendicular to the surface of the plate but is inclined at a predetermined angle of 90 degrees or less (for example, 60 degrees or 45 degrees). It may be provided. The electromagnetic shielding effect SE of a perforated metal plate provided with a large number of holes inclined in a certain direction, the diameter, arrangement and pitch of holes in a direction perpendicular to the surface of the metal plate provided on a metal plate of the same thickness, Electromagnetic shielding effect not less inferior to electromagnetic shielding effect SE when the holed metal plate provided with the inclined holes has the same diameter, arrangement and pitch as the holes on the projection plane from the direction of the holes. Indicates SE.

The portion corresponding to the operation section of the portable telephone is made openable and closable when a plate made of an inflexible electromagnetic shielding material is used, for example.
The operation of the telephone is performed by opening the openable portion, and after ending the operation and entering a talking state, the openable portion is closed to maintain the electromagnetic shielding effect at a predetermined level. When the mobile phone has a display unit, a portion corresponding to the display unit may be configured to be openable or closable, or a portion corresponding to the display unit may be an electromagnetic shield material that allows the display unit to be easily seen through, for example, Use an EBP-processed perforated metal plate with a particularly high aperture ratio to improve the transparency, or use a transparent resin plate such as an acrylic resin to provide an electromagnetic shielding effect and obliquely forward perspective. A transparent electromagnetic shielding material in which a mesh having good performance is cast is used. Also, the joint between the electromagnetic shielding materials forming the case, and the joint between the main body side portion when the portion made of the electromagnetic shielding material that can be opened and closed is closed, if necessary, a known suitable A conductive and elastic gasket-like electromagnetic shielding material is used so that the electromagnetic shielding effect is not reduced.

In the present invention, the perforated metal plate having holes formed by EBP processing has holes of a predetermined diameter formed in a predetermined substantially uniform distribution over the entire surface of the metal plate as a case forming material. It is not always necessary that holes having a predetermined diameter are formed only in necessary portions in the case forming member at a predetermined arrangement and pitch, and there is no hole in the remaining portion. Alternatively, even if a hole is provided, the aperture ratio may be reduced so that rigidity and strength are advantageously maintained.

As a preferable material example of the perforated metal plate in which holes are formed by the EBP processing, ferrite (Mn—Zn, Ni—Zn, Mg—Mn, Mg—Mn)
Ni-Zn system, Ni-Cu-Zn system), iron and iron alloys (electromagnetic soft iron, carbonyl iron, silicon steel, alpalm, sendust, iron chromium alloy, iron nickel chromium alloy), permalloy (78 permalloy, 45 permalloy, mu Metal, Supermalloy, Amorphous (Co-Fe-B)
-Si-based, Co-Nb-Zr-based) soft magnetic metal materials.

Preferred examples of the material of the electromagnetic shielding material other than the metal plate perforated by EBP processing, which is used as a part of the member (forming) of the electromagnetic shielding case for a portable telephone according to the present invention, have been exemplified above. Powders of any one or two or more of powders of radio wave absorber material obtained by adding carbon, graphite and carbon fiber to each soft magnetic metal material and these soft magnetic metal materials, and various kinds of synthesis as binder Resin (polyamide, polypropylene, polyester, polybutylene terephthalate, vinyl chloride, urethane resin, polyimide, polyphenylene sulfide, ABS, polycarbonate, etc.) and rubber (chloroprene rubber, silicone rubber, urethane rubber,
An electromagnetic-wave-absorbing molding material in which any one or a combination of two or more of fluororubber, EPDM, natural rubber, butyl rubber, chlorosulfonated polyethylene, and chlorine or polyethylene are combined. In addition, when using the electromagnetic shielding material of conductive resin, elastomer or rubber including the above, it is more effective to cast or line a net or wire loop of a conductive material such as metal. It is preferable because electromagnetic waves can be converted into electric current and absorbed.

According to a second aspect of the present invention, there is provided the electromagnetic shield case for a portable telephone according to the first aspect, wherein the portable telephone has a display portion, and further includes at least a display portion. A perforated metal plate in which holes are formed by electron beam drilling is used as the electromagnetic shielding material of the corresponding portion.

According to a second aspect of the present invention, there is provided an electromagnetically shielded case for a portable telephone set according to the first aspect, wherein at least a portion corresponding to a display section of the telephone set is formed by EBP processing. Use a perforated metal plate. For this reason, when the display on the display unit is a light-emitting display, the display (message or the like) on the display unit is changed to the above E
It can be easily read from the outside of the perforated metal plate by the BP processing, especially at night or in a room that is not very bright such as in a room. Further, the aperture ratio of the perforated metal plate used in this portion or the necessary portion in the EBP process is made larger than the aperture ratio of the perforated metal plate used in the other portions, so that the aperture ratio of the display portion of the mobile phone is increased. It is easy to make the transparency from the top of the case sufficiently high and to maintain the necessary rigidity and strength of the case itself as a whole.

According to a third aspect of the present invention, there is provided the electromagnetic shield case for a mobile phone according to the first aspect, wherein the mobile phone includes a display unit, and further includes at least the display unit and the display unit. A perforated metal plate having holes formed by an electron beam perforation process is used as an electromagnetic shielding material for a corresponding portion of the operation unit of the mobile phone, and at least a corresponding portion of the operation unit is configured to be openable and closable. Features.

According to a third aspect of the present invention, there is provided an electromagnetic shield case for a mobile phone according to the first aspect, wherein the display portion and the operation portion of the mobile phone are also EBP-processed. A perforated metal plate was used, and at least a portion corresponding to the operation unit was configured to be freely openable and closable. For this reason, when the display of the display unit or the push button of the operation unit is a light emitting display, the display (message or the like) of the display unit or the display of the push button is changed to the above E.
Being able to easily read from outside the perforated metal plate by BP processing, especially at night or indoors where it is not very bright, as a result, it is possible to talk while confirming the operating state of the mobile phone to some extent from the outside of the electromagnetic shield case Is preferred. Further, the aperture ratio of the perforated metal plate used for the corresponding portion of the display portion and the operation portion or the necessary portion in the EBP process is made larger than the aperture ratio of the perforated metal plate used for the other portions, so that the cellular phone It is easy to make the visibility of the display section and the operation section from above the case sufficiently high, and to maintain the necessary rigidity and strength of the case itself as a whole. Note that at least the corresponding portion of the operation unit is configured to be openable and closable, so that when it is necessary to operate a push button or the like of the operation unit, the operation can be performed by opening the openable and closable portion each time. .

According to a fourth aspect of the present invention, there is provided an electromagnetically shielded case for a mobile phone according to the first aspect, wherein the mobile phone has a display unit, and the electromagnetically shielded portion corresponding to the display unit is provided. As a shielding material, a transparent electromagnetic shielding material other than a perforated metal plate is used, and a perforated metal having a hole formed by an electron beam drilling process is used for an electromagnetic shielding material corresponding to an operation unit of a mobile phone. It is characterized in that a plate is used and the corresponding part of the operation unit is configured to be openable and closable.

According to a fourth aspect of the present invention, there is provided the electromagnetic shield case for a mobile phone according to the first aspect, wherein a portion corresponding to the display portion of the mobile phone is made of a light-transmitting material such as an acrylic resin. A wire mesh having an electromagnetic shielding property and good transparency is cast into a transparent resin plate, or a transparent electromagnetic shielding material in which the wire mesh is lined with the light-transmitting resin plate is used. Therefore, the message displayed on the display unit from the outside of the electromagnetic shield case can be read easily and from a wider angle (more obliquely forward) than when a perforated metal plate by EBP processing is used, and the electromagnetic shield effect can be obtained. Can not be significantly impaired. Therefore, in the case of using the pager function provided when the mobile phone is a PHS, for example, to read the message displayed on the display unit, in any case, from above the electromagnetic shield case, and from above, diagonally. It is relatively easy to enable reading. A perforated metal plate having holes formed by electron beam perforation processing was used for a corresponding portion of the mobile phone operation unit, and the corresponding portion of the operation unit was configured to be freely openable and closable. Therefore, when the display of the push button or the like of the operation unit is a light-emitting display, the display (message or the like) of the display unit or the display of the push button is displayed on the perforated metal plate by the EBP processing, particularly at night or at night. It is preferable to be able to read easily in a place that is not very bright such as indoors, and as a result it is possible to make a call while confirming the operating state of the mobile phone to some extent from outside the electromagnetic shield case. Further, the aperture ratio in a necessary portion of the metal plate perforated by EBP processing used for the corresponding portion of the operation portion is made larger than the aperture ratio of the other portions to improve the transparency of the operation portion of the mobile phone from above the case. It is easy to make the case sufficiently good and to maintain the required rigidity and strength of the case itself as a whole. In addition, since the corresponding portion of the operation unit is configured to be openable and closable, when the operation of the push button of the operation unit or the like needs to be performed, the operation can be performed by opening the openable and closable portion each time.

According to a fifth aspect of the present invention, there is provided the electromagnetic shield case for a mobile phone according to the first aspect, wherein the electromagnetic shield material for the corresponding portion of the operation unit of the mobile phone is flexible. It is characterized in that a transparent electromagnetic shielding material is used, and a pressing operation of a lower push button can be performed by pressing from above.

According to a fifth aspect of the present invention, there is provided the electromagnetic shield case for a portable telephone set according to the first aspect, wherein the electromagnetic shield case has a flexible and transparent view at a portion corresponding to an operation portion of the mobile phone. Using a material, pressing operation of the lower push button was enabled by pressing from above. Therefore, the operation of the mobile phone can be performed without opening and closing a part of the electromagnetic shield case, which is convenient, and a constant electromagnetic shield effect is always maintained because the part of the electromagnetic shield case is not opened. Can be. In addition, as a flexible and transparent electromagnetic shielding material capable of performing such a function, for example, a transparent thin metal wire having a transparent and electromagnetic shielding effect in a thin flexible sheet of transparent resin is used. Examples thereof include those in which a wire mesh is sealed, and those in which the metal thin wire wire mesh is lined with the flexible sheet.

According to a sixth aspect of the present invention, there is provided an electromagnetic shield case for a portable telephone according to the first aspect of the present invention, wherein the electromagnetic shield case is mainly formed by electron beam drilling. It is characterized in that a perforated metal plate with holes is used.

According to a sixth aspect of the present invention, there is provided an electromagnetically shielded case for a portable telephone according to the first aspect of the present invention, wherein the electromagnetically shielded case is mainly used as a main component (main component) of the electromagnetically shielded case. A perforated metal plate by EBP processing was used. Therefore, the electromagnetic shield case has an original electromagnetic shield effect and a good propagation of acoustic signals including voices, has a possibility of seeing a main part of a mobile phone from above the case, and further has a ventilation as a whole case. The case can be easily made lightweight, having the required rigidity as a case.

[0022]

1 to 3 show an electromagnetic shield case for a portable telephone according to a first embodiment of the present invention. FIG. 1 is an enlarged view of the surface of a perforated metal plate formed by EBP processing, which is a main forming material of the electromagnetic shield case of this embodiment, and FIG. 2 is a perspective view of the electromagnetic shield case in which a mobile phone is accommodated. FIG. 3 is a perspective view of the electromagnetic shield case in a state where an openable and closable portion is opened.

The electromagnetic shield case (hereinafter simply referred to as a case) 1 for a portable telephone according to this embodiment is a bottomed cylindrical body having a vertically-long and substantially square cross section as a whole, as shown in FIG. Holes 11b having a predetermined small diameter are formed mainly over the entire surface of a stainless steel plate 11a of a predetermined thickness by processing, mainly using a perforated stainless steel plate 11 formed at a predetermined arrangement and at an interval. Here, the perforated stainless steel plate 11 has a thickness (t) of 0.5 mm,
The hole diameter (d) is 0.15 mm, therefore, the ratio (t / d) of the plate thickness to the hole diameter is 3.3, and the pitch (p) of the hole arrangement is 0.3 m.
The m is 60 degrees staggered and the aperture ratio is about 23% (see FIG. 1). FIG. 2 shows a state in which the case 1 is erected on a horizontal plane. In this state, the mobile phone 100 is inserted and stored in the case 1 from above the case 1 with the antenna 101 of the mobile phone 100 in an upright posture. Portions of the case 1 corresponding to the back surface and both side surfaces of the mobile phone 100 are formed of a grooved stainless steel plate 11A with holes formed by EBP processing. A portion of the case 1 corresponding to a speaker unit (not shown) provided near the upper front of the mobile phone 100 is the above-described grooved perforated stainless steel plate 11.
A and after combining in a predetermined state where the grooves face each other, by welding, joining with conductive adhesive or screwing, etc.
If necessary, a shallow groove-shaped EBP process is applied to the overlapping part (joint) with a conductive and elastic gasket-like electromagnetic shielding material interposed to prevent leakage of electromagnetic waves. A perforated stainless steel plate 11B is provided. Further, a microphone unit (not shown) provided on the case 1 near the lower front of the mobile phone 100.
In the portion corresponding to the above, a stainless steel plate 11C having a shallow groove formed by EBP processing and having the same shape as that of the stainless steel plate 11B having a shallow groove is provided by the same method. A portion of the case 1 corresponding to the display unit 102 and the operation unit 103 provided near the front center of the mobile phone 100, that is, the above-described shallow grooved perforated stainless steel plate 11B.
A stainless steel plate 11D perforated by EBP processing of a shallow groove, which is also relatively shallow in the groove direction, is provided on the front part intermediate between the shallow groove and the shallow groove. Hinge 12 provided between stainless steel plate 11C
It can be freely opened and closed by the functions of a and 12b, however, if necessary, between the grooved perforated stainless steel plate 11A and the shallow grooved stainless steel plates 11B and 11C so as to prevent leakage of electromagnetic waves when closed. The gasket-like electromagnetic shielding material is interposed at the joint. Although not shown, an ordinary stainless steel bottom plate is fixed to the bottom of the case 1 so that the electromagnetic shielding property is maintained even at the joint. In a portion of the case 1 corresponding to the upper surface portion of the mobile phone 100, a cover plate 13 made of a normal stainless steel is also provided here.
1 and is detachably attached to the grooved perforated stainless steel plate 11A using appropriate means. When the lid plate 13 is also attached, the electromagnetic shielding property is maintained at the joint between the grooved perforated stainless steel plate 11A and the shallow grooved stainless steel plate 11B. In addition, the surface of the inside corner of the electromagnetic shield case 1, the bottom surface, and the ceiling surface (the cover plate 1)
3 (inner side), a cushion material 14 is attached to the case surface so that the mobile phone 1 can be moved or the like.
00 does not receive an impact force from the case 1.

The electromagnetic shield case 1 for a mobile phone according to the first embodiment is used after the mobile phone 100 is housed in the case 1 and the cover plate 13 is closed. When the ringing tone of the mobile phone 100 sounds, the ringing tone can be transmitted to the outside through the perforated stainless steel plate forming the front and side surfaces of the case 1 with little attenuation and reach a remote position. When the ringing tone is heard, the openable portion (the shallow groove-shaped stainless steel plate 11D) on the front of the case is opened to expose the operation unit 103, and the call start button is pressed to switch to the call start state. Immediately after the switching, the openable and closable part is closed, and then the case 1 is lifted up by hand to start a call. When making a call, open the above openable / closable portion (shallow-groove-shaped stainless steel plate 11D) and operate the push button to input the telephone number of the other party and wait for a response. As soon as you are on the phone, close the above openable and closable part and start talking.
Therefore, most of the time when the case 1 containing the mobile phone is arranged close to the head, such as during a call, communication radio waves are radiated from the tip of the antenna 101 extending high above the head. However, radio waves leaking from the mobile phone main body at a position close to the head of the human body are subjected to EBP processing to form a so-called Faraday cage made of an electromagnetic shielding material mainly made of a perforated stainless steel plate. Is greatly attenuated, and the amount of radio wave energy irradiated to the human body is suppressed to a remarkably small amount. In addition, during a call, the audio signal is propagated through the stainless steel plate 11B or 11C perforated by EBP forming the portion corresponding to the speaker portion or the portion corresponding to the microphone portion of the electromagnetic shield case 1 with almost no attenuation. E constituting the front and side surfaces of the case 1
Case 1 through perforated stainless steel plate by BP processing
Ventilation between the inside and outside air is sufficiently performed. Further, since the case 1 is formed mainly by using a perforated stainless steel plate formed by EBP processing with an aperture ratio of about 23%, the case 1 exhibits considerable transparency and is light and robust.

Next, FIGS. 4 and 5 show an electromagnetic shield case for a portable telephone according to a second embodiment of the present invention. FIG.
FIG. 5 is a perspective view of an electromagnetic shield case in which a mobile phone is housed, and FIG. 5 is a perspective view of the electromagnetic shield case in a state where an openable and closable portion is opened.

An electromagnetic shield case (hereinafter simply referred to as a case) 2 for a mobile phone according to this embodiment has a vertically long cross-section that is substantially square as shown in the figure, as in the case of the first embodiment. The bottom cylindrical body is made of EBP
Mainly a perforated stainless steel plate 21 (here, the same as the perforated stainless steel plate of the first embodiment) in which holes having a predetermined small diameter are formed at predetermined positions and intervals over the entire surface of a stainless steel plate having a predetermined thickness by processing. It is made using. The figure shows a state in which the case 2 is erected on a horizontal plane.
Numeral 0 is inserted and stored in the case 2 with the antenna 101 standing upright. The portions of the case 2 corresponding to the back surface and both side surfaces of the mobile phone 100 are grooved E-shaped portions.
It is formed of a perforated stainless steel plate 21A by BP processing. The grooved perforated stainless steel plate 21A
The left and right edges extending in the longitudinal direction of the
A metal frame 22, which forms a mold, is mounted in a slit groove formed on an end surface of the stainless steel plate 21A by permitting the press-fitting of both end edges of the perforated stainless steel plate 21A. In a portion of the case 2 corresponding to the display unit 102 provided on the front of the mobile phone 100 and slightly above,
A transparent electromagnetic shielding material, in which a wire mesh having an electromagnetic shielding effect and transparency is cast in a transparent electromagnetic shielding material other than a perforated metal plate, in this case, a transparent resin plate such as an acrylic resin.
3 is mounted in a slit groove formed along the end face of the H-shaped frame body 22 with the lower edge and the left and right side edges being strongly pressed. Case 2 immediately above
A part corresponding to a speaker unit (not shown) provided near the upper front of the mobile phone 100 has a predetermined E
A perforated stainless steel plate 21B formed by the BP process is attached to the left and right edges by being strongly pressed into slit grooves formed along the end surface of the H-shaped frame 22. A portion of the case 2 corresponding to the operation unit 103 and the microphone unit (not shown) provided from the center of the front surface of the mobile phone 100 to the lower side thereof is provided with a vertically elongated EBP-processed stainless steel plate 21C as a whole. The upper and left and right edge portions are inserted into slit grooves formed along the end surface of the H-shaped frame body 22. However, if necessary, conductive grooves are formed in the grooves so as to realize electromagnetic shielding. By interposing and inserting a magnetic and elastic gasket-like electromagnetic shielding material,
It is slidably mounted and constitutes an opening and closing part. or,
The lower end edge of the perforated stainless steel plate 21C is curled forward, and is used as a finger hook when the perforated stainless steel plate 21C as an openable / closable portion is pulled down or returned to its original position. In addition, using appropriate means,
In the closed position where the perforated stainless steel plate 21c is pulled up at least upward, the stainless steel plate 21c is kept stopped unless a downward pressing force is applied. Although not shown, an ordinary stainless steel bottom plate is provided on the bottom of the case 2 so as to cooperate with the perforated stainless steel plate 21C which slides the case 2 so that the electromagnetic shielding property is maintained. Somehow fixed. Mobile phone 10 of case 2
In the portion corresponding to the upper surface of the portable telephone 100, a stainless steel cover plate 24 having no ordinary holes is also provided here.
Through the antenna 101, and is detachably attached to the grooved perforated stainless steel plate 21A, the H-shaped frame 22, and the perforated stainless steel plate 21B by using appropriate means. I have. The cover plate 24
Also, in the mounted state, the electromagnetic shielding property is maintained between the above members. The electromagnetic shield case 2
The cushion material 25 is attached to the case surface at important points such as the surface forming the inner corner, the bottom surface, and the ceiling surface (the inner surface of the lid plate 24). 100 does not receive an impact force from the case 2.

The electromagnetic shield case 2 for a mobile phone according to the second embodiment is also used after the mobile phone 100 is housed in the case 2 and the cover plate 24 is closed. The operation and effect of the case 2 are as follows. Since the electromagnetic shielding material having good transparency other than the perforated metal plate is used for the portion corresponding to the display portion of the mobile phone, the display of messages and the like on the display portion is performed by the case. 2
Other than that it is easy to read from the top and relatively diagonally forward direction, and the electromagnetic shielding effect does not need to be reduced so much that it is convenient.
The electromagnetic shield case 1 for the mobile phone according to the first embodiment.
Is the same as

In the electromagnetic shield cases for portable telephones of the first and second embodiments, the metal plate perforated by EBP processing used for the display part and / or the corresponding part of the operation part of the telephone is used for other parts. The same perforated metal plate formed by EBP processing was used, and the perforated metal plate had a large number of holes provided in a uniform distribution over almost the entire surface. On the other hand, only a necessary portion (region) of the corresponding portion is perforated, and the pitch of the holes in that portion is particularly small so that the aperture ratio of this portion is higher than that of the other portions. The electromagnetic shielding case has a large aperture ratio, for example, an aperture ratio of 50% or more, and further enhances the transparency without deteriorating the electromagnetic shielding property and advantageously preventing the reduction in rigidity and strength as a whole. It can also be.

In the electromagnetic shielding case for a mobile phone made of an electromagnetic shielding material according to the invention described above, at least a portion corresponding to a speaker portion and a microphone portion of the mobile phone has a hole formed by forming a large number of holes in a metal plate by EBP processing. High electromagnetic shielding effect (SE) using plate
And an electromagnetic shield case which does not impair the sound propagation property while maintaining necessary rigidity (strength) and light weight. On the other hand, for example, any one or two or more combination powders of the above-mentioned various radio wave absorber material powders, which can be made lighter than the metal material, and various synthetic resins and rubbers also as the above-mentioned binders A conductive resin, elastomer or rubber plate, including one formed from an electromagnetic-wave-absorbing composite molding material obtained by compounding one or two or more combinations, is used to form a small hole having a predetermined diameter into a predetermined hole. A perforated plate made of conductive resin or rubber, which is provided at an arrangement and a pitch (accordingly, an aperture ratio), can be made thicker because of a lower specific gravity than a metal plate, and accordingly, the hole diameter can be correspondingly increased. The electromagnetic shielding effect (SE) can be made the same even if is increased, so that a machining method that does not necessarily depend on the EBP machining for machining a large number of holes, for example, machining is relatively advantageously employed. The ability.

Therefore, an electromagnetic shield case for a mobile phone, which is formed of an electromagnetic shield material and is capable of housing the mobile phone except for the antenna portion, wherein the electromagnetic shield material is made of a conductive resin, elastomer or rubber. The material is used overall or almost entirely,
And a conductive resin or elastomer in which holes of a predetermined diameter are provided at a predetermined arrangement and pitch in the conductive resin, elastomer or rubber plate at least in a portion of the case including a speaker portion and a microphone portion of the mobile phone. Alternatively, an electromagnetically shielded case for a cellular phone using a perforated plate made of rubber is another one which is similarly useful in that the overall weight is light and the feel held by hand is superior to metal. Electromagnetic shield case for two mobile phones. Also in this case, the above-mentioned perforated plate of the conductive resin, elastomer or rubber is used for securing necessary air permeability or a certain degree of transparency to other necessary or desired parts of the case. When the mobile phone has a display unit, the display unit, the portion corresponding to the operation unit of the mobile phone, and the portion for taking the mobile phone in and out have a structure that can be opened and closed or removable as needed or desired. In addition, embedding a net or a wire loop of a conductive material such as a metal in an electromagnetic shielding material using the above-mentioned conductive resin, elastomer or rubber, or lining the electromagnetic shielding material, improves the electromagnetic shielding property. It is more preferable to increase the value.

In another electromagnetic shielding case for a portable telephone using the electromagnetic shielding material of the conductive resin, elastomer or rubber as a whole or almost entirely, in particular, a part corresponding to a display portion of the portable telephone is provided. For example, a wire mesh having an electromagnetic shielding property and good transparency is cast into a light-transmitting resin plate such as an acrylic resin, or the wire mesh is lined with the light-transmitting resin plate, and a transparent electromagnetic shield is provided. A material can also be used.

The other one of the electromagnetic shielding cases for the portable telephone, particularly the speaker and microphone, using the electromagnetic shielding material of the conductive resin, the elastomer or the rubber as a whole. In place of the above-mentioned perforated plate made of conductive resin, elastomer or rubber, a portable telephone using a cloth braid of a fine metal wire having an electromagnetic shielding property and a large number of minute holes and having good sound signal propagation properties. The electromagnetic shielding case for the portable telephone also becomes another useful electromagnetic shielding case for the mobile phone.

Further, the electromagnetic shielding case for the other one or other second portable telephone using the electromagnetic shielding material of the conductive resin, elastomer or rubber as a whole or almost entirely, especially, In the corresponding portion of the operation unit, for example, a thin flexible sheet made of a transparent resin and a flexible thin metal wire net having a see-through and electromagnetic shielding effect sealed therein, or the thin metal wire is attached to the flexible sheet. An electromagnetic shield case for a mobile phone which uses a flexible and transparent electromagnetic shield material, which may be a wire mesh-lined material, and which allows pressing operation of a lower push button by pressing from above, is also known. This is another useful electromagnetic shielding case for a third mobile phone.

Further, in any of the above-described other first to third electromagnetic shielding cases for portable telephones,
The electromagnetic shielding case for a mobile phone, wherein the electromagnetic shielding material made of conductive resin, elastomer or rubber forms an elastic body, receives a large impact force from the case when the mobile phone stored in the case is moving or the like. This prevents another, similarly useful electromagnetic shield case for a fourth mobile phone.

[Brief description of the drawings]

FIG. 1 is an enlarged view of the surface of a perforated metal plate formed by EBP processing, which is a main component of the electromagnetic shield case of the first embodiment.

FIG. 2 is a perspective view of the electromagnetic shield case for a mobile phone according to the first embodiment in a state in which the mobile phone is accommodated.

FIG. 3 is a perspective view showing a state where an openable and closable portion of the electromagnetic shield case is opened.

FIG. 4 is a perspective view of an electromagnetic shield case for a mobile phone according to a second embodiment in a state in which the mobile phone is accommodated.

FIG. 5 is a perspective view showing a state where an openable and closable portion of the electromagnetic shield case is opened.

[Explanation of symbols]

1, 2 ... Electromagnetic shield case for mobile phone 11 ... Perforated stainless steel plate with holes formed by electron beam drilling 11b ... Holes formed by electron beam drilling 11B, 21B ... Speaker part corresponding part (electron beam Perforated metal plate with holes formed by perforation processing) 11C, 21C ... Microphone part corresponding part (perforated metal plate with holes formed by electron beam perforation processing) 100 ... Cellular phone

Claims (6)

[Claims] 1. An electromagnetic shield case for a mobile phone formed of an electromagnetic shield material and capable of storing a mobile phone except for an antenna portion, wherein at least a portion corresponding to a speaker section and a macrophone section of the mobile phone is provided. An electromagnetic shield case for a mobile phone, wherein a perforated metal plate having holes formed by electron beam perforation processing is used as a shield material. 2. The electromagnetic shield case for a mobile phone according to claim 1, wherein the mobile phone has a display unit, and further, as a magnetic shielding material for at least a corresponding portion of the display unit, holes are formed by electron beam drilling. An electromagnetic shield case for a mobile phone, characterized by using a perforated metal plate formed with holes. 3. The electromagnetic shield case for a mobile phone according to claim 1, wherein the mobile phone has a display unit, and further includes at least the display unit and an electromagnetic shield material corresponding to an operation unit of the mobile phone. An electromagnetic shield case for a mobile phone, wherein a perforated metal plate having holes formed by electron beam perforation is used, and at least a portion corresponding to the operation unit is openable and closable. 4. The electromagnetic shield case for a mobile phone according to claim 1, wherein the mobile phone has a display unit, and as an electromagnetic shield material for a corresponding portion of the display unit, a transparent material other than a perforated metal plate. Using an electromagnetic shield material, a perforated metal plate with holes formed by electron beam drilling is used as the electromagnetic shield material for the corresponding part of the operation part of the mobile phone, and the corresponding part of the operation part can be opened and closed freely. An electromagnetic shield case for a mobile phone. 5. The electromagnetic shielding case for a mobile phone according to claim 1, wherein a flexible and transparent electromagnetic shielding material is used as an electromagnetic shielding material for a corresponding portion of an operation unit of the mobile phone, and pressing from above is performed. 2. An electromagnetic shield case for a mobile phone, wherein a lower push button can be pressed by a button. 6. The electromagnetic shield case for a mobile phone according to claim 1, wherein a perforated metal plate having holes formed by electron beam drilling is used as a main material of the electromagnetic shield case. Electromagnetic shield case for mobile phones.