JPH07263931A - Cordless telephone system - Google Patents

Abstract

PURPOSE:To obtain the incorporated loop antenna of high performance which has a high gain and is hardly affected by human bodies. CONSTITUTION:A groove 4 is formed in the junction part between a lower case 3 and an upper case 2. A linear conductor 5 is stored in the groove 4, and both end parts 5a and 5b of the linear conductor 5 are led into a case 1 and are connected to a radio circuit 8 through a matching circuit 7 in the case 1. A magnetic field detection type loop antenna is constituted, and a loop area can be made large. Thus, a satisfactory gain is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cordless telephone device,
In particular, it relates to a built-in antenna.

[0002]

2. Description of the Related Art A built-in antenna is mainly used as an antenna for a slave unit in a conventional cordless telephone device because portability is important. As the built-in antenna, generally, a shortened antenna in which the rod-shaped whip antenna length is shortened by devising the arrangement of the antenna pattern or by loading inductance, or a loop antenna formed in a loop by a linear conductor is used.

FIG. 2 shows an example of the configuration of a conventional slave unit. As shown in FIG. 2, the slave unit main body 21 includes a loop antenna 22 formed of a loop-shaped linear conductor, a radio circuit 23, a matching circuit 24 for impedance matching of the loop antenna 22, and a control circuit. And 25 are stored. The built-in loop antenna 22 is housed in an empty space inside the main body 21 of the slave unit and is connected to the wireless circuit 23 via the matching circuit 24.
Operates as a transmitting antenna and a receiving antenna together with the radio circuit 23.

FIG. 3 shows another example of the configuration of a conventional slave unit. As shown in FIG. 3, the slave unit main body 31 accommodates a shortened antenna 32, a wireless circuit 33, a matching circuit 34 for impedance matching of the shortened antenna 32, and a control circuit 35. The built-in shortened antenna 32 is stored in an empty space above the inside of the slave unit main body 31,
The built-in shortened antenna 32 is connected to the wireless circuit 33 via the matching circuit 34, and operates together with the wireless circuit 33 as a transmitting antenna and a receiving antenna.

[0005]

Among the above-mentioned conventional examples, in the case of the shortened antenna 32 shown in FIG. 3, the antenna gain is not as great as that of the external antenna attached to the outside of the case, but there is no problem in practical use. It can be secured with a degree. However, the shortened antenna 32 is an electric field detection type antenna, and when the slave unit is used in close contact with the human body such as the head and hands, the electric field is absorbed and attenuated by the influence of the human body and the antenna performance deteriorates. Will end up.

On the other hand, the built-in loop antenna 22 shown in FIG.
Is a magnetic field detection type antenna, and the performance deterioration due to the human body as described above does not occur. However, in the case of the built-in loop antenna 22, although the area of the loop needs to be increased in order to obtain the antenna gain, the empty space inside the child device where portability is important is generally small. Therefore, as a result, the loop area of the loop antenna cannot be sufficiently taken, and it is difficult to obtain a good antenna gain.

The present invention solves the above-mentioned conventional problems, and can prevent the performance deterioration due to the human body in the magnetic field detection type. Moreover, the loop area can be increased to obtain a good antenna gain. Therefore, it is possible to secure the distance, so that it is possible to extend the reach of radio waves in actual use even though it is a built-in antenna. Also, the case itself can be effectively used to reduce the size of the entire device. It is intended to provide a telephone device.

[0008]

In order to achieve the above object, the cordless telephone device of the present invention has a loop antenna made of a linear conductor housed in a groove formed in a joint portion between an upper case and a lower case. A linear conductor, that is, both ends of the loop antenna are connected to a radio circuit provided in the case.

[0009]

Therefore, according to the present invention, since it is the magnetic field detection type loop antenna, it is possible to prevent the performance deterioration due to the human body, and moreover, the area of the loop due to the linear conductor is set along the outer peripheral portion of the case. Since it can be made large, it can be made considerably larger than when it is stored in an empty space inside the cordless handset, good antenna gain can be secured, and the loop antenna is stored by effectively using the case itself. Therefore, it is possible to reduce the volume by the space conventionally built in the case.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cordless telephone device according to an embodiment of the present invention, and is a schematic explanatory view of a state in which an upper case is opened. This embodiment is applied to a child device.

As shown in FIG. 1, a case 1 of a slave unit is composed of an upper case 2 and a lower case 3, and a groove 4 is formed along the entire circumference of a joint portion of the lower case 3 with the upper case 2. ing. A linear conductor 5 is accommodated in the groove 4, and both ends 5a and 5b of the linear conductor 5 are passed through the notch 6 opened inward at the end of the lower case 3 following the groove 4. It is guided into the lower case 3. Therefore, during the assembling process, the linear conductor 5 is housed in the groove 4 provided in the joint portion in the state where the lower case 3 and the upper case 2 are joined.

A linear conductor 5 (antenna) is provided in the case 1.
A matching circuit 7 including a capacitor and an inductance for impedance matching, a wireless circuit 8 connected to the matching circuit 7, a matching circuit 7 and a wireless circuit 8
A control circuit 9 that controls the operations such as the above is housed, and a linear conductor 5 is connected to a wireless circuit 8 via a matching circuit 7.

Then, the linear conductor 5 operates as a transmitting antenna and a receiving antenna together with the radio circuit 8. At this time, in this embodiment, since the linear conductor 5 can act as a loop antenna having an area having a size along the outer circumference of the case 1 of the slave unit, it is possible to prevent performance deterioration due to a human body. It is possible to secure a good antenna gain, and it is possible to extend the radio wave reach distance during actual use even though it is a built-in antenna. Further, since the linear conductor 5 is housed in the case 1 itself, the antenna space in the case 1 unlike the conventional built-in antenna is unnecessary.

In the above embodiment, the groove 4 is formed on the lower case 3 side, but the groove is formed so as to extend over the upper case 2 side or both the lower case 3 and the upper case 2. The conductor 5 may be housed, and in short, the linear conductor 5 may be formed in the groove formed at the joint between the upper case 2 and the lower case 3.
Should be stored. Further, in the above embodiment,
Although the case of application to the child device has been described, it is needless to say that the same configuration may be applied to the parent device to which the telephone circuit is connected without being limited to this.

[0016]

As described above, according to the present invention,
Since it is configured as a loop antenna that is housed along the grooves of the upper and lower case joints, it is possible to prevent performance deterioration due to the human body, and yet to ensure a good antenna gain by enlarging the area of the loop. it can. Therefore, even though the antenna is a built-in antenna, it is possible to extend the reach of radio waves during actual use. In addition, since the volume of the case can be reduced by the antenna space inside the main body of the related art, the device can be downsized.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an example in which the present invention is applied to a child device as an embodiment and an upper case is opened.

FIG. 2 is a schematic explanatory view showing a slave unit using a built-in loop antenna as a conventional example.

FIG. 3 is a schematic explanatory view showing a slave unit using a shortened antenna as another conventional example.

[Explanation of symbols]

 1 case 2 upper case 3 lower case 4 groove 5 linear conductor 7 matching circuit 8 wireless circuit 9 control circuit

Claims (1)

[Claims] 1. A linear conductor is housed in a groove formed in a joint portion between an upper case and a lower case of the case, and both ends of the linear conductor are connected to a wireless circuit provided in the case. A cordless telephone device characterized in that