JP2001320457A - Mobile wireless unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce a local average SAR(Specific Absorption Rate) in an operating state. SOLUTION: A nonconductive case 11 is provided with communication control sections 23, 26 or the like that are shielded by a shield body such as a ground conductor 14 and a conductive case 15 and with output devices 18, 21 that reproduce outputs from the communication control sections. A magnetic loss material layer section 22 is provided to a mount face of the shield body on which at least the output devices are mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a portable radio device such as a portable telephone mainly used by a user while holding it.

[0002]

2. Description of the Related Art For example, portable telephones that have become remarkably widespread have been reduced in size, weight, and function, and generally have a housing made of a non-conductive material. In a mobile phone, a circuit board, a dial unit,
Components such as a speaker, a microphone, and a liquid crystal display are incorporated. The mobile phone is provided with a telescopic antenna at an upper part of a housing and a secondary battery of a power supply is mounted.

In a portable telephone, an integrated circuit component or an electronic component constituting an appropriate circuit portion such as a radio transmission / reception circuit, a transmission / reception control circuit, a memory circuit, a power supply circuit, etc., is formed on a main surface of a circuit board on which a circuit pattern is formed. And so on. In a mobile phone, a liquid crystal display is provided between a speaker and a microphone due to restrictions on the configuration.

In a portable telephone, various circuit parts mounted on a circuit board are shielded by a board ground or a shield case in order to suppress mutual influence or influence on an antenna and other devices. ing. On the other hand, in a mobile phone, a high-frequency current flows through the substrate ground and the shield case during use, so that not only the antenna but also the entire device has an antenna function. In a mobile phone, a part of the electromagnetic waves emitted to the outside, though weak, is absorbed by the human body, especially the head of the user. Therefore, in mobile phones, reducing electromagnetic waves absorbed by the human body and improving communication efficiency have become major issues.

[0005]

In a portable telephone, a SAR (Specific Absorption Rate) value, which is an absorbed electric power value per unit mass, is used as an evaluation value, and a local average SAR value which is the maximum is considered. Measures are required to reduce the value to a specified value or less. The SAR value is expressed as follows: E is the electric field absorbed by the human body, σ is the dielectric constant of the human body, and ρ is the density of the human body.
Then, SAR = σE ² / 2ρ.

In the portable telephone 1, the above-described regulation condition of the local average SAR value is applied in a state where the housing 2 is gripped and used. In the mobile phone 1, as shown in FIG. 9, the housing 2 is gripped and used so that the speaker 3 built in the housing 2 is applied to the ear 6 of the human head 5. In the mobile phone 1, as described above, the board ground and the shield case of the circuit board on which the speaker 3 and the liquid crystal display 4 are mounted act as an antenna and serve as a source of electromagnetic waves. For this reason, in the mobile phone 1, it is analyzed that the local average SAR value is maximized in a portion facing the speaker 3 and the liquid crystal display 4, as indicated by a broken line A in FIG. Therefore, the present invention provides a local average SAR
The present invention has been proposed for the purpose of providing a portable wireless device capable of effectively conforming to a value regulation condition.

[0007]

A portable radio device according to the present invention that achieves the above-mentioned object is provided in a non-conductive casing.
A communication control unit shielded by a shield such as a ground conductor or a conductive case, and an output unit for reproducing an output from the communication control unit. A damaged material layer is provided.

[0008] According to the portable radio apparatus according to the present invention having the above-described configuration, the magnetic lossy material layer shields the vicinity of the output device located closest to the human body (head) in use. The high-frequency current flowing through the body is partly converted into heat. According to the portable wireless device, the electromagnetic wave emitted from the vicinity of the output device is reduced without impairing the antenna output, so that the local average SAR value can be effectively reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a portable telephone 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the mobile phone 10 is formed by combining an upper half and a lower half made of a non-conductive material into a housing 1 having a vertically long thin box shape.
1, a circuit board 12 is incorporated. Although not shown in detail, the mobile phone 10 includes a wireless transmission / reception circuit for performing wireless communication with a base station, a transmission / reception control circuit, a memory circuit, a power supply circuit, and the like on front and back main surfaces of a circuit board 12 on which a circuit pattern is formed. An integrated circuit component, an electronic component, an electric component, or the like that forms an appropriate circuit unit is mounted.

[0010] Each of these circuit sections is appropriately shielded in order to suppress mutual influence or influence on the antenna 13 and other devices. The shielding process is performed, for example, by mounting the substrate ground 14 on the surface of the circuit board 12.
And a shield case 15 (15a to 15a) in which each circuit portion is formed by applying a metal powder to a metal case or an inner surface.
It is shielded by covering with c).

An antenna 13 is arranged at the upper end of a housing 11 of the mobile phone 10. The antenna 13 has an appropriate form such as a rod type, a helical type, or a telescopic type obtained by combining these. The antenna 13 can be extended or retracted or pulled out of the housing 11 via an antenna feeding metal fitting 16 whose details are omitted. Installed. The antenna 13 transmits and receives transmission signals to and from the base station via an antenna feed spring 17 formed of a conductive spring material that connects between the antenna feed fitting 16 and a predetermined circuit portion of the circuit board 12.

Regardless of the type of the antenna 13 used in the mobile phone 10, the antenna 13 alone does not have the function of transmitting and receiving transmission / reception signals, and the substrate ground 14 and the shield case 15 will be described in detail later. A high-frequency current flows on the surface, and the whole functions as an antenna.

The cellular phone 10 has built-in components such as a speaker 18, a microphone 19, a dial unit 20, and a liquid crystal display 21. Mobile phone 10
Although not shown, a rechargeable secondary battery is stored on the back side, and a charging terminal is disposed on the bottom surface. The speaker 18 is provided on a surface of a shield case 15a mounted on an upper end portion of the circuit board 12 with a magnetic loss material 2 described later.
Attached via 2. The speaker 18 has a sound emitting portion facing a sound emitting hole formed in the upper half of the housing 11.

The microphone 19 is provided on the surface of a shield case 15b mounted on the lower end of the circuit board 12,
Are arranged so as to face the sound collection holes formed in the upper half. Although not described in detail, the dial unit 20 includes a unit case in which a key board, a dial key, a dial control circuit unit, and the like are combined, and is mounted on a surface of a shield case 15b mounted in an area below the circuit board 12. . The dial unit 20 is provided with function keys for setting various functions, a power key, and the like, in addition to the dial keys. Note that the mobile phone 10 includes
Although not shown, for example, a jog dial or the like is provided on a side surface of the housing 11.

The liquid crystal display 21 is located between the microphone 19 and the dial unit 20 and is mounted on the main surface of the circuit board 12. The liquid crystal display 21 has a display surface facing a display section formed on the upper half of the housing 11.

The mobile phone 10 performs a transmission / reception operation of a transmission / reception signal with the base station as shown in FIG. That is, in the mobile phone 10, the dial unit 20
An input signal from the speaker 18 or the like is supplied to the transmission circuit unit 23, and the transmission circuit unit 23 generates a transmission signal in a predetermined signal format. In the mobile phone 10, the generated transmission signal is transmitted from the antenna 13 to the base station via the transmission / reception changeover switch unit (duplexer in the case of the dual signal system) 24 and the matching circuit unit 25. The matching circuit unit 25 is a circuit unit that performs a matching operation between the characteristic impedance of the transmission / reception circuit units 23 and 26 and the input impedance of the antenna 13.

In mobile phone 10, a reception signal transmitted from a base station is received by antenna 13. In the mobile phone 10, the received signal is received by the receiving circuit 26 via the matching circuit 25 and the transmission / reception switch 24. In the mobile phone 10, the receiving circuit 26 demodulates the received signal to generate an output signal, and supplies the output signal to the speaker 18 and the liquid crystal display 21 for output.

In the mobile phone 10, the speaker 18 is attached to the shield case 15a via the magnetically damaged material 22 as described above. The magnetic loss material 22 is formed in a sheet shape from a magnetic loss material obtained by kneading powder such as ferrite, permalloy, sendust, stainless steel, iron-based amorphous alloy or flat powder with a chlorinated polyethylene resin or a silicon resin. Although not shown, a through-hole for penetrating an input terminal and the like of the speaker 18 is formed in the magnetic loss material 22, and is attached to the surface of the shield case 15a with an appropriate adhesive.

The magnetic lossy material 22 has an effect of reducing a high-frequency current flowing on the surface of the shield case 15a as described later.
Also, it has an effect of absorbing vibrations and the like applied to 8. In addition, the magnetic loss material 22 is not limited to the above-described materials,
It may be formed of any other appropriate material having a magnetic field absorbing effect. The magnetic loss material 22 is formed by, for example, kneading an adhesive material into the above-described material to form a shield case 15a.
You may make it apply | coat to the surface of.

In the portable telephone 10, as shown in the current distribution of FIG. 4A, a high-frequency current flows through the surface of the substrate ground 14 and the surface of the shield case 15, and the antenna feed spring 1
By reaching the antenna 13 via the antenna feeder 7 and the antenna feeder 16, the whole is configured to have an antenna function. In the mobile phone 10, part of the electromagnetic wave generated by the high-frequency current is absorbed by the user's head 5 and the rest is radiated from the antenna 13.

In the portable telephone 10, the effect of electromagnetic waves emitted from the vicinity of the speaker 18 applied to the ear 6 of the head 5 in the use state is greatest. Mobile phone 1
The magnetic loss material 22 is attached to the surface of the shield case 15a on which the speaker 18 is provided, as described above.
Accordingly, in the mobile phone 10, as shown in the current distribution of FIG. 4B, a part of the high-frequency current flowing through the shield case 15a is thermally converted by the magnetic loss material 22 to be reduced, and a path change occurs.

In the portable telephone 10, the amount of electromagnetic waves emitted from the vicinity of the speaker 18 is reduced due to the change in the current distribution of the high-frequency current. Of course,
In the mobile phone 10, a part of the high-frequency current at a portion corresponding to the speaker 18 is reduced, but hardly affects the output from the antenna 13. Mobile phone 1
In the case of 0, the local average S which is maximum in the use state
Standards are achieved by effectively reducing the AR value.

The portable telephone 30 shown in FIGS. 5 and 6 as a second embodiment of the present invention is characterized in that a magnetic loss member 31 is provided corresponding to the liquid crystal display 21. Since the mobile phone 30 has substantially the same other basic configuration as the above-described mobile phone 10, the corresponding parts are denoted by the same reference numerals and detailed description thereof will be omitted.

In the portable telephone 30, depending on the electrical dimensions of the antenna 13 and the electrical dimensions of the substrate ground 14 or the shield case 15, the maximum point of the local average SAR value is larger than that of the mobile phone 1 described above. The position is slightly shifted downward from the vicinity of. Therefore, in the mobile phone 30, the magnetic loss material 31 is provided at a position corresponding to the liquid crystal display 21 which is disposed below the speaker 18 and has the maximum local average SAR value.

The magnetic loss material 31 is also made of powder or flat powder of ferrite, permalloy, sendust, stainless steel, iron-based amorphous alloy or the like, as in the case of the magnetic loss material 22 described above.
It is formed into a sheet from a magnetically lossy material kneaded with chlorinated polyethylene resin or silicone resin. Magnetic loss material 3
Reference numeral 1 has a size enough to cover the mounting area of the liquid crystal display 21 and has a cutout (not shown) through which a connector and the like penetrate. The magnetic loss material 31 is bonded to the main surface of the circuit board 12 with an adhesive.

In the mobile phone 30, at a portion corresponding to the liquid crystal display 21, a part of the high-frequency current flowing on the surface of the substrate ground 14 of the circuit board 12 is thermally converted by the magnetic loss material 31 to be reduced. Occurs. The mobile phone 30 uses the liquid crystal display 2
The amount of electromagnetic waves emitted from near 1 is reduced. In the mobile phone 30, the local average SAR value that is consequently maximized is reduced, and the standard conformity is achieved.

A portable telephone 40 shown in FIGS. 7 and 8 as a third embodiment of the present invention has a first magnetic loss material 41 and a second magnetic loss material 41 corresponding to the speaker 18 and the liquid crystal display 21. It has a feature in the configuration in which the magnetic loss material 42 is provided. Since the other basic configurations of the mobile phone 40 are almost the same as those of the above-described mobile phones 10 and 30, the corresponding parts are denoted by the same reference numerals and detailed description thereof will be omitted.

In the mobile phone 40 as well, the maximum location of the local average SAR value is determined by the electrical dimensions of the antenna 13 and the substrate ground 1.
4 or a position corresponding to the liquid crystal display 21 slightly shifted downward from the vicinity of the speaker 18 depending on the electrical dimensions of the shield case 15. In the mobile phone 40, the speaker 18 is applied to the ear 6 of the head 5 in the usage mode, so that the speaker 18 is located closest to the head 5. Therefore, in the mobile phone 40, the first magnetic loss material 41 and the second magnetic loss material 42 are provided at the portions corresponding to the speaker 18 and the liquid crystal display 21, respectively.

The first magnetic loss material 41 and the second magnetic loss material 42
Also, similarly to the magnetic loss material 22 described above, a powder or flat powder of ferrite, permalloy, sendust, stainless steel, iron-based amorphous alloy, or the like is formed into a sheet shape using a magnetic loss material obtained by kneading with chlorinated polyethylene resin or silicon resin. Be done. Although not shown, the first magnetic loss material 41 is formed with a through-hole for penetrating an input terminal of the speaker 18 and the like, and is attached to the surface of the shield case 15a with an appropriate adhesive. Second magnetic loss material 42
Has a size sufficient to cover the mounting area of the liquid crystal display 21 and has a notch (not shown) through which a connector and the like penetrate. The second magnetic loss material 42 is bonded to the main surface of the circuit board 12 by an adhesive.

The portable telephone 40 has a shield case 15a and a board ground 14 of the circuit board 12 formed by a first magnetic loss material 41 and a second magnetic loss material 42 at corresponding portions of the speaker 18 and the liquid crystal display 21, respectively. A part of the high-frequency current flowing on the surface is reduced by heat conversion,
A path change occurs. Therefore, in the mobile phone 40, the amount of electromagnetic waves emitted from the vicinity of the speaker 18 and the liquid crystal display 21 is reduced by the change in the current distribution. The mobile phone 40 has a local average S that results in a maximum.
The AR value is reduced to achieve standard conformity.

The present invention is not limited to the portable telephones shown in the above-described embodiments, but various types of wireless devices that transmit and receive data signals and the like by a wireless method and that are used by being gripped by a user. Applies to equipment. The wireless device is not limited to a mobile phone in which the antenna 13 is connected to the transmission / reception circuits 23 and 26 to perform bidirectional transmission and reception as in the embodiment, but may be a transmission-only or reception-only type, for example.

According to the present invention, the magnetic loss materials 22, 31 and 4 corresponding to the above-described speaker 18 and / or liquid crystal display 21 are provided.
However, the present invention is not limited to the configuration in which the first and second units are provided, and may be provided corresponding to other output units that show a large local average SAR value in a usage pattern. Speaker 18
Is provided in the shield case 15, but may be directly mounted on the circuit board 12 having the board ground 14. Further, the liquid crystal display 21 is provided on the circuit board 12 having the board ground 14, but the shield case 1
5 may be provided.

In the present invention, the sheet-shaped magnetic loss material formed of the above-described material is used in correspondence with the substrate ground 14 and the shield case 15, but other materials having magnetic loss characteristics may be used. Of course. In addition, the magnetic loss material is not limited to a sheet.

[0034]

As described above in detail, according to the portable radio apparatus of the present invention, at least the magnetic loss is present on the mounting surface of the shield body on which the output device which is positioned closest to the human body in use is mounted. Since the material layer portion is provided and a part of the high-frequency current flowing through the shield is reduced by heat conversion in the magnetic loss material layer portion, electromagnetic waves emitted from the vicinity of the output device are reduced, and in use, An apparatus that effectively reduces the maximum local average SAR value and meets severe regulatory conditions can be realized.

[Brief description of the drawings]

FIG. 1 is a main part longitudinal sectional view for explaining a schematic configuration of a mobile phone shown as a first embodiment of the present invention.

FIG. 2 is an essential part front view showing the mobile phone with a front case removed.

FIG. 3 is a block diagram illustrating an outline of a circuit configuration of the mobile phone.

4A and 4B are explanatory diagrams of a current distribution of a high-frequency current in a mobile phone. FIG. 4A shows a conventional example, and FIG. 4B shows an embodiment.

FIG. 5 is an essential part longitudinal cross sectional view for explaining a schematic configuration of a mobile phone shown as a second embodiment of the present invention.

FIG. 6 is an essential part front view showing the mobile phone with a front case removed.

FIG. 7 is a main part longitudinal sectional view illustrating a schematic configuration of a mobile phone shown as a third embodiment of the present invention.

FIG. 8 is an essential part front view showing the mobile phone with a front case removed.

FIG. 9 is an explanatory diagram of a use state of the mobile phone.

[Description of information]

Reference Signs List 10 mobile phone, 11 case, 12 circuit board, 13
Antenna, 14 Board ground, 15 Shield case, 18 Speaker, 19 Microphone, 20 Dial unit, 21 Liquid crystal display, 22 Magnetic loss material, 2
Reference Signs List 3 transmission circuit section, 26 reception circuit section, 30 mobile phone, 31 magnetic loss material, 40 mobile phone, 41 first magnetic loss material, 42 first magnetic loss material

Continued on the front page (72) Inventor Junichi Toyoda 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Katsumi Okayama 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony F term in the company (reference) 5E321 AA01 BB25 CC16 GG05 GG11 5J047 AA17 AB06 FA09 5K023 AA07 BB23 BB28 LL06 5K067 AA06 AA26 BB04 KK01 KK17

Claims (3)

[Claims] 1. A communication control unit, which is shielded by a shield body such as a ground conductor or a conductive case, and an output device for reproducing an output from the communication control unit in a non-conductive casing. A portable wireless device, wherein a magnetic loss material layer portion is provided on a mounting surface of the shield body on which an output device is mounted. 2. The speaker according to claim 1, wherein the output device is a speaker attached to a circuit board constituting the communication control unit or a shield case mounted on the circuit board. The portable wireless device according to claim 1, wherein: 3. The output device is a liquid crystal display attached to a circuit board constituting the communication control section or a shield case mounted on the circuit board, and is attached via the magnetic loss material layer. The portable wireless device according to claim 1, wherein: