JPH0265502A - Antenna and radio equipment mounted on arm - Google Patents

Abstract

PURPOSE:To transmit and receive a signal of a prescribed frequency by adopting the structure such that a capacitance is provided to a connector main body equipped to attach/detach a loop antenna to/from an arm and the capacitance is varied automatically with the length of the loop antenna. CONSTITUTION:A metal plate 5 and the loop antenna 4 are opposite to each other while having insulators 2, 11 inbetween and the opposed part forms a capacitance. With the insulator 2 including the loop antenna 4 drawn out, since the opposed area between the metallic plate 5 and the loop antenna 4 is decreased, the said capacitance is decreased. With the insulator 2 inserted to the depth of the connector main body 12 conversely, since the opposed area is increased, the said capacitance is increased. When the length of the loop antenna 4 is increased in this way, that is, the inductance of the loop antenna 4 is increased, the capacitance of the connector main body 12 is automatically decreased. The processing opposite to above is implemented automatically, and any deviation from a tuned frequency does not take place.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small portable radio device, particularly an antenna structure and a wrist-worn radio tJH using the antenna structure.

[Prior Art] In the conventional art, such a connector is either electrically conductive or insulated, and in the latter case, it has a coupling capacitance (hereinafter referred to as capacitance).
This value remains constant even if the length of the loop antenna changes.

[Problems to be Solved by the Invention] However, when such conventional connectors are used, it is extremely difficult to always ensure electrical continuity because the connectors are repeatedly connected and disconnected many times. Additionally, if the length of the loop antenna changes when it is insulated and provided with capacitance, the resonant frequency will shift when the loop antenna is viewed as part of a resonant circuit, making it impossible to tune to the desired frequency. become.

Therefore, in order to solve these conventional problems, the present invention has a connector structure that automatically changes the capacitance according to the change in the length of the loop amplifier, so that it can always be tuned to the target frequency. The purpose is to provide an antenna.

In addition, a wrist-worn radio device that is characterized by having such an antenna can always receive the same frequency for any loop antenna length, so it can accommodate people with any size of arms, and This makes it possible to freely adjust the size of the loop antenna to the size that is most convenient for use.

[Means for Solving the Problems] In order to solve the above problems, the antenna of the present invention is a loop antenna that is separate from an arm band to be worn on the arm, and a part of the loop antenna is separated and attached to the arm. The present invention is characterized in that a connector main body serving as a means for attaching and detaching has an electrical coupling capacity, and has a connector structure that automatically changes the coupling capacity according to a change in the length of the loop antenna.

Furthermore, when such an antenna is attached to a wrist-worn radio device, a wrist-worn radio device that is integrated with the two components is constructed.

1 Effect] As mentioned above, when the length of the loop antenna changes, the area where the loop antennas overlap in position changes, and that area determines the capacitance. If the loop antenna is long, its capacitance will be small. Conversely, if it is short, it becomes large. This increase or decrease in capacitance is automatically determined by changing the length of the loop antenna by λ, without any intervention.

[Embodiment 1] Fig. 1 is an embodiment of the antenna connector main body of the present invention, and is a longitudinal sectional view thereof. In order to prevent the human body from being affected by @, the loop antenna 3.4 is covered with an insulator 1.2. The loop antenna 3 and the insulator 1 go around the arm and are connected to the loop antenna 4 and the insulator 2, respectively. The loop antenna 3 is connected to a high frequency amplification circuit of a radio device inside the connector main body 12. The insulator 2 is processed at a portion connected to the connector body 12, and a saw-shaped pawl 6 is formed. And that claw 6
The width of the loop antenna 4 increases within a certain range, and the width of the insulator 2 also increases correspondingly.

On the other hand, on the bottom side of the connector body 12, the connector body 1
There is a metal plate 5 covered with a second insulator 11. metal plate 5
is connected to a high frequency amplification circuit of a radio device connected to the connector main body 12. This metal plate 5 and the loop antenna 4 face each other with the insulators 2 and 11 in between, and this portion becomes a capacitance. When the insulator 2 including the loop antenna 4 is pulled out, this capacitance becomes as follows.
Since the area where the metal plate 5 and the loop antenna 4 face each other becomes smaller, the size becomes smaller. Conversely, connect the insulator 2 to the connector body 12
The deeper you insert it, the larger the opposing area becomes, so it becomes larger. In this way, making the loop antenna 4 longer,
In other words, when the inductance of the loop antenna 4 is increased, the capacitance formed in the connector body 12 is automatically decreased, and vice versa. .

As a method of fixing the insulator 2, there is a pawl 9 that engages with the pawl 6. The pawl 9 is integrated with the push button 7, and is supported by the fulcrum 8. 6 In the normal state,
The claw 9 side is pushed down, and even if you pull the insulator 2, the claw 6 and claw 9 are engaged, so it won't come out.However, when inserting it, the opposite side of the claw 6 should be at an angle. It's easy because there are If you want to pull out the insulator 2, press the push button 7, and the pawl 9 will rise, disengaging the pawls 6 and 9 and allowing the insulator 2 to be pulled out.

FIG. 2 is an equivalent circuit diagram of FIG. 1 of a resonant circuit including the antenna of the present invention. There is an inductance la of the loop antenna 3.4, a capacitance 2a formed in the connector body 12, and another capacitance 3a for forming a resonant circuit. In order to keep the tuning frequency of this resonant circuit constant, the product of the sum of the reciprocals of the respective capacitances of capacitances 2a and 3a and the inductance la should always be kept constant. , because when the inductance la changes, the capacitance 2a automatically changes correspondingly.

This means that you can always tune to a certain frequency.

FIG. 3 is a diagram showing an embodiment in which the antenna of the present invention is attached to a wristwatch type radio. A radio device is contained within the watch body 14. This radio is connected to gold@board 5,
From here, the desired signal is generated manually. Since the loop antenna 4 and the metal plate 5 are mostly covered by the insulator 2.1, they do not come into direct contact with each other. Therefore, there is no contact failure due to surface abrasion or dust, so the reliability is high. In addition, although the loop antenna 4 and the connector main body 12 are always carried with you, there is no possibility that the loop antenna 4 or the connector main body 12 will be corroded by human sweat, etc., and since the length can be arbitrarily determined within a certain range of the claw 6, it can be easily attached to your arm. It is easy to use because you can use it at your desired length regardless of the thickness.

FIG. 4 is a diagram showing an embodiment in which the connector body 12 of the antenna of the present invention is attached to a buckle. By forming the connector body 12 integrally with the buckle 20, the loop antenna 3.
There are three supporting points for the insulators 1 and 2 including the wristwatch main body 14 and the buckle 20, and distortion of the loop antenna caused by external forces can be reduced. Furthermore, it is possible to prevent the loop container from coming close to the surface of the human body.

FIG. 5 shows the fourth connector body 12 of the antenna of the present invention.
It is a longitudinal cross-sectional view in the case of a figure. A capacitance is formed in the overlap between loop antennas 3 and 4. Other explanations are the same as in the embodiment shown in FIG.

FIG. 6 shows the antenna of the present invention. 5 is an equivalent circuit diagram of a resonant circuit in the embodiment of FIG. 4. FIG. Loop antenna 3
．． 4 corresponds to inductances 4a and 5a, respectively. Also, the capacitance formed in the connector body 12 is 2a, and another capacitance forming the resonance @ path is 3a.
It is. In order to keep the tuning frequency of the resonant circuit constant,
The sum of inductances 4a and 5a and capacitance 2a
, 3a, it is sufficient that the product of the sum of the reciprocals of 3a is always constant.3 According to the present invention, when the inserted length of the loop antenna 4 changes and the inductances 4a and 5a change, the capacitance 2a also changes. The value of the aforementioned product can always be constant, and therefore the tuning frequency can be kept constant.

Effects of the Invention 1 As explained above, in the antenna of the present invention, the connector body provided for attaching and detaching the loop antenna to the arm has a capacitance, and the capacitance is automatically adjusted according to the length of the loop antenna. By adopting a structure in which the loop antenna is varied, a constant frequency can be transmitted and received regardless of the length of the loop antenna. Furthermore, since the metal parts of the loop antenna do not come into direct contact with each other in the connector body, there is no contact failure or corrosion (and high reliability).

In addition, a wrist-mounted PA-free device equipped with such an antenna can easily transmit and receive constant frequency signals without any special adjustment by any person, regardless of the thickness of the arm.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the antenna connector main body of the present invention. FIG. 2 is an equivalent circuit diagram of FIG. 1 of a resonant circuit including the antenna of the present invention. FIG. 3 is a diagram showing an embodiment in which the antenna of the present invention is attached to a wristwatch type radio device. FIG. 4 is an embodiment of the antenna connector body of the present invention attached to a buckle. FIG. 5 is a longitudinal sectional view of FIG. 4 of the connector main body of the antenna of the present invention. FIG. 6 is an equivalent circuit diagram of FIG. 4 of a resonant circuit including the antenna of the present invention. 1.2, 11 ・ ・ ・ 3, 4 ・ ・ ・ ・ ・ 1a, 4a, 5a ・ 2a, 3a ・ ・ ・ ・ 5 ・ ・ ・ ・ ・ ・ ・ 6, 9 ・ ・ ・ ・ ・ ・ 7 ・・ ・ ・ ・ . １４ ・ ・ ・ ・ ・ ２０ ・ ・ ・ ・ ・ ・・コネクタ本体・・腕バンド・・腕時計本体・・尾錠以出願人 セイコーエプソン株式会社代理人 弁理士 上 柳 雅 誉（他１名）５ＥＪ

Claims (2)

[Claims] (1) In a loop antenna that is separate from an arm band to be worn on the arm, a connector main body serving as a means for detaching and attaching a part of the loop antenna to the arm has an electrical coupling capacity, and the loop antenna An antenna characterized by having a connector structure that automatically changes the coupling capacitance according to a change in the length of the antenna. (2) A wrist-worn radio device, characterized in that the antenna described in item 1 is attached.