JPH04227301A - wrist-worn radio - Google Patents

Abstract

PURPOSE:To prevent fluctuation in a radio equipment characteristic possibly occurred due to a contact with a human body in the wrist mount radio equipment and to avoid a damage to the circuit of the radio equipment or occurrence of malfunction due to invasion of static electricity from the human body. CONSTITUTION:A couple of varactor diodes 11, 12 being components of a resonance circuit are connected in parallel with a loop antenna 5 integrated in a wrist band of the wrist watch type receiver to form an electric balance circuit. A rear cover 2b of the radio equipment main body and a mid-fastener 7 in contact with the human body and made of a conductor member are connected respectively to a neutral point of the balanced circuit.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrist-worn radio device such as a wristwatch type receiver. For more details,
The present invention relates to a structure for preventing the deterioration of reception sensitivity and the intrusion of static electricity that occur due to contact with the human body in arm-worn radio equipment that has a conductive part that comes into contact with the human body when worn on the arm. It is.

0002

2. Description of the Related Art A wristwatch-type receiver is known as one type of wrist-worn radio device. In order to reduce the size and weight of such receivers, various structural improvements have been made. For example, in order to reduce the size of the receiver body, it has been proposed to use a band antenna in which the receiver antenna is incorporated into a wrist band. Furthermore, in order to reduce the number of connected parts inside the receiver body, it has been proposed to form the receiver body case or its back cover from a conductive material and use this part as a circuit component.

FIGS. 1 and 2 show an example of a wristwatch type receiver having such a structure. As shown in these figures, the wristwatch-type receiver 1 includes a receiver body 2 and a pair of bands 3R and 3L attached to both sides of the receiver body 2. The receiver main body 2 is composed of a case 2a, a back cover 2b, and a receiver circuit block 4 of a laminated structure arranged in a housing formed by these. Normally, a battery 40 is attached to the back cover side of the receiver circuit block 4, and the back cover 2b is used as an electrode component of this battery 40. The pair of bands 3R and 3L are formed from a flexible resin material, and antennas 5R and 5L made of conductive plates are incorporated inside the bands. At the base end sides of these antennas 5R and 5L, there are antenna terminals 6R and 6 that penetrate through the side of the case 2a and protrude into the inside of the case 2a, respectively.
L is fixed. These terminals are in contact with antenna input terminal electrodes 41 and 42 formed on the sides of the receiver circuit block 4, respectively. An engaging metal fitting 7R and its receiving metal fitting 7L made of a conductive member are attached to the distal ends of the antennas 5R and 5L, respectively, and these constitute an intermediate fastening metal fitting 7 of the antenna. By connecting the antenna using this middle clasp 7, the receiver 1
can be attached to the arm. Moreover, when these are connected, a loop antenna 5 is formed by a pair of antennas 5R and 5L connected through these.

The receiver circuit block 4 has a structure in which, for example, multilayer circuit boards are stacked with spacers in between. The battery 40 attached to the back cover is a thin button battery in order to reduce the weight of the receiver. The negative electrode 40a of the battery 40 is connected via an electrode plate 45 to a negative electrode pattern (not shown) formed on a circuit board 46, which is a component of the circuit block. battery 4
The positive side electrode 40b of 0 is connected to a positive side electrode pattern (not shown) formed on the circuit board 46 via an electrode plate 47 shaped like a leaf spring and an electrode plate 48 shaped like a coil spring. As shown in the figure, the electrode plate 47 is also in contact with the back cover 2b, and this back cover 2b forms part of the power supply circuit.

[0005]

When the wrist-mounted radio device having such a structure is worn on the arm, the loop antenna's inner clasp 7 and the back cover 2b come into contact with the human body. Since the inner clasp 7 is made of a conductive member, if this part comes into contact with the human body, there is a risk that the current distribution on the conductor forming the antenna circuit will be influenced and changed. When the current distribution changes, the antenna
This causes a decrease in gain, a decrease in Q value in the antenna circuit, etc. As a result, the sensitivity of the antenna decreases, making it impossible to obtain an antenna mechanism and circuit configuration that operate well in a practical frequency range. however,
In the past, no effective countermeasures against the deterioration in sensitivity caused by such contact with the human body have been proposed.

[0006] On the other hand, as a problem that occurs with contact with the human body, there is destruction of the radio circuit due to the invasion of static electricity from the human body side. As a countermeasure against static electricity, for example, a method shown in FIG. 3 is adopted. In this method, a diode 8 is connected in series to the antenna 5, and static electricity that enters from the antenna side is discharged to the ground pattern side via the diode. This is to prevent it from entering the circuit 9 side. However, adding a diode increases the capacitance that resonates with the antenna and forms the antenna tuning circuit. As a result, an inability to tune occurs at a specific frequency that should normally be tuned. As described above, no effective static electricity countermeasure that does not cause deterioration of sensitivity has been proposed in the past.

An object of the present invention is to address these conventional problems and to realize a wrist-worn radio device having a structure capable of preventing deterioration in sensitivity caused by contact with the human body. Another object of the present invention is to realize a wrist-worn radio device having an anti-static structure that does not cause deterioration in sensitivity.

[0008]

[Means and operations for solving the problem] In order to solve the above-mentioned problem of preventing deterioration of sensitivity, the wrist-worn radio device of the present invention has a part made of a conductive member that can come into contact with the human body when it is worn. It is characterized by being set to the AC ground potential of the built-in radio circuit. A typical part made of a conductive member is the case of the radio device or the back cover of the case. Here, in order to set such a part to the AC ground potential, connect the part made of this conductive member directly or indirectly through another conductive member to the ground electrode of the radio circuit. good. Even if this is not done, in a wrist-worn radio device in which the antenna built into the arm band portion is connected by a clasp made of a conductive material to form a loop antenna when worn on the wrist, a balanced circuit formed by the loop antenna can be used. What is necessary is to connect the part made of a conductive member to the neutral point of the part. In addition to this, the clasp is also preferably connected to a substantial neutral point in this balanced circuit section.

[0009] In the wrist-worn radio device of the present invention configured as described above, when the radio device is worn on the arm, the case back cover, inner clasp member, etc. made of a conductive material are set to the AC ground potential of the radio circuit. . Therefore, even if these conductive parts come into contact with the human body, there is little electrical influence on the radio circuit. As a result, characteristic deterioration such as receiving sensitivity caused by contact with a human body does not substantially occur.

[0010] Next, in order to solve the problem of preventing static electricity, the present invention, when worn on the wrist, connects the antennas built into the armband to each other with a clasp made of a conductive member. In a wrist-worn radio device in which a loop antenna is formed, an antenna tuning circuit is configured that is connected in parallel to the loop antenna and has a capacity to resonate with the loop antenna and configure the tuning circuit. A circuit element is connected to the positive or negative electrode of the radio circuit, thereby forming an electrostatic discharge path between the clasp member and the electrode via this circuit element. There is.

Examples of such circuit elements include a pair of varactor diodes connected in series facing each other and forming an antenna tuning circuit. In this case, the midpoint between these varactor diodes is connected to the positive or negative electrode of the radio circuit.

[0012] If the case or back cover of the radio device is made of a conductive material, the varactor diode can be connected to the positive or negative electrode of the radio circuit by connecting this conductive material to the positive or negative electrode of the radio circuit. A discharge path for static electricity may be formed between the clasp member and the conductive member through the clasp member and the conductive member.

In the wrist-worn radio device of the present invention, which is equipped with such a discharge path, when static electricity enters the loop antenna from the clasp due to contact with the human body, the intruded static electricity is discharged by the varactor diode. is discharged to the earth side via the line. Here, since the discharge path formed in this manner is not constructed by adding any circuit element therefor, the capacitance of the antenna tuning circuit does not fluctuate. Therefore, the antenna characteristics do not change.

On the other hand, the discharge path for static electricity that has entered from the human body side can also be configured via a spark gap. For example, a spark gap may be formed between a pair of antenna parts forming a loop antenna. or,
A spark gap may be formed between the antenna portion and the positive or negative electrode side of the power source of the radio circuit. Furthermore, in an arm-mounted radio device that includes a portion made of a conductive member that can be contacted with the human body when worn on the arm, a spark gap may be formed between the portion made of the conductive member and the antenna portion.

[0015] In the wrist-worn radio device of the present invention having a discharge path including a spark gap as described above, under normal operating conditions, the discharge path is electrically cut off at the spark gap. Therefore, variations in antenna characteristics such as variations in the capacitance of the tuning circuit of the loop antenna do not occur due to the formation of the discharge path.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. In each of the following embodiments, the present invention is applied to a wristwatch type receiver, and the overall configuration of the receiver is the same as that shown in FIGS. 1 and 2. Therefore, in the figures showing the following embodiments, parts corresponding to those shown in FIGS. 1 and 2 are designated with the same reference numerals.

(First Embodiment) FIG. 4 shows the configuration of a receiver circuit in which the inner clasp 7 of the loop antenna 7 of the wristwatch type receiver 1 is set to an AC ground potential. In the example shown in this figure, a resonant circuit is formed by a loop antenna 7 and a pair of batacta diodes 11 and 12 connected in parallel to the loop antenna 7. The varactor diodes 11 and 12 have their cathodes connected to each other. A resistor 13 is connected to the intersection 14 between the anode side of one varactor diode 11 and the antenna input terminal electrode 41, and a tuned frequency control voltage is applied to the resonant circuit via this resistor 13. There is. An intersection 15 on the cathode side of the pair of varactor diodes 11 and 12 is connected to a positive electrode 40b of a power supply battery 40 of the receiver. Such a connection is formed by a positive electrode pattern formed on the circuit board 46 constituting the receiver circuit block. Of course, a circuit configuration may be adopted in which the intersection point 15 is directly connected to the positive electrode 40b of the battery.

In this example, one varactor diode 11, 12 has the same characteristics, and these diodes are normally formed in one package, as seen in FM receivers and the like. Since the capacitances of the varactor diodes are equal in this way, the resonant circuit constituted by the loop antenna 5 and these varactor diodes 11 and 12 substantially constitutes a balanced circuit, and the position of the inner fastener 7 and the varactor The positions of the intersection points 15 of the diodes each serve as a substantial neutral point. As described above, in this example, since the intersection 15 is connected to the positive electrode side of the battery 40, the potential here is set to the ground potential in terms of AC. Therefore, the other neutral point, that is, the part of the inner clasp 7 is also equivalently at the ground potential.

Note that the latter stage side of the resonant circuit is connected to the RF amplifier circuit 18 via coupling capacitors 16 and 17.

When the receiver 1 of this example constructed as described above is worn on the arm, the back cover 2b and the inner clasp 7 of the receiver come into contact with the arm. As mentioned above, the back cover 2b is made of a conductive member and is connected to the ground potential on the circuit, so the arm side is also connected to the ground potential on the circuit via the back cover 2b. As a result, the potential of the arm itself is also fixed to the ground potential. Therefore, even if the back cover 2b made of a conductive member comes into contact with the arm, there will be no direct electrical adverse effect on the receiver circuit. Furthermore, since the back cover 2b is set to the ground potential, this back cover also blocks the electrostatic coupling between the arm side and the receiver circuit side. On the other hand, on the side of the middle clasp 7, this part is equivalently at ground potential, so even if this part comes into contact with the arm side, there will be no adverse electrical effect on the receiver circuit side. . In particular, in this example, the ground potential on the circuit is set by the arm coming into contact with the back cover side, so that almost no adverse effects occur.

As described above, according to this example, since the back cover 2b and the inner clasp 7 are each set to the ground potential on the circuit, even if they come into contact with the arm, there will be no contact with the receiver circuit side. No adverse electrical effects occur. Therefore, the sensitivity of the receiver can be maintained in an appropriate state.

[0022] Here, the antistatic structure of the receiver 1 of this example will be explained. In the receiver 1 of this example,
When the receiver is worn on the arm, static electricity may enter the receiver circuit from the arm side via the back cover 2b and the inner clasp 7 made of conductive material. First, with reference to FIG. 5, a case will be described in which static electricity intrudes from these parts while the inner fastener 7 is fastened. When static electricity enters from the side of the inner clasp 7, the static electricity travels through a discharge path passing through the loop antenna 5 (5R, 5L), the varactor diodes 11, 12, and the back cover 2b, as shown by the solid arrow in the figure. discharged to the outside through the On the other hand, when static electricity enters from the back cover 2b, it flows in the opposite direction through the discharge path and is discharged from the inner clasp 7 to the outside, as shown by the dotted arrow in the figure.

In either case, static electricity does not invade the RF amplifier circuit 18 side.

Next, as shown in FIG. 6, when the inner fastener 7 is not fastened, a discharge path is formed as follows. That is, as shown by the solid arrow, static electricity that has entered from the side of the back cover 2b is discharged to the outside via the varactor diodes 11 and 12 and the metal fittings on the grounded side, in the illustrated example, the metal fitting 7L. Furthermore, static electricity that has entered from the side of the other metal fitting 7R is discharged to the outside from the grounded side of the other metal fitting 7L or the back cover 2b via the varactor diodes 11 and 12.

[0025] Thus, in the receiver 1 of this example,
A discharge path is formed in a portion of the antenna resonant circuit. Therefore, static electricity that has entered from the arm side is discharged to the outside without entering the receiver circuit. Therefore, it is possible to prevent internal circuit elements from being damaged by electrostatic discharge.

(Modification of the first embodiment) Next, FIGS.
and 9 show modified examples of this example. First, Figure 7
In the example shown in FIG.
is grounded to ground potential in an alternating current manner. In this example, a frequency control voltage is applied to the intersection 15 via the resistor 20.

Here, the voltage applied via the resistor 13 may be a fixed voltage or a variable voltage. In order to apply a fixed voltage, for example, the resistor 13 may be connected to the negative electrode of the battery 40. The example shown in FIG. 8 is an example in which an intersection 15 of varactor diodes 11 and 12 is connected to a negative electrode 40a of a battery 40 via a bypass capacitor 19. On the other hand, in the example shown in FIG.
This is an example in which capacitors 21 and 22 are inserted between each anode of No. 2 to isolate them in terms of direct current. These capacitors 21, 22 have the same constant and are connected in series with each diode. Therefore, a balanced circuit is also configured in this example. Note that a control voltage is applied to the anode side of each of the diodes 11 and 12 via resistors 13 and 20, respectively. In each of these examples, Fig. 4
Effects similar to those of the embodiment shown in can be obtained.

On the other hand, in each of the embodiments described above, only the back cover 2b of the case 2a and the back cover 2b constituting the receiver main body is made of a conductive member. However, case 2a
It can also be formed from a conductive material. In this case,
The side of the case 2a is also set to the ground potential, and the receiver circuit is completely covered by the case 2a and the back cover 2b, which are set to the ground potential. The receiver circuit is therefore protected against static electricity. In addition, noise generated from the receiver circuit side is blocked, and adverse effects such as reduction in sensitivity of an external loop antenna due to generated noise can be prevented.

Next, in each of the embodiments described above, the cathodes of the varactor diodes 11 and 12 are connected in series, but the anodes may be connected in series. FIG. 10 shows a circuit section of a receiver with varactor diodes 11, 12 connected in this way. Even in this case, since a balanced circuit is formed by the loop antenna 5 and these varactor diodes 11 and 12, the same effects as in each of the above-described embodiments can be obtained.

(Second Embodiment) Next, FIG. 11 schematically shows the antenna circuit portion of a receiver which is a second embodiment of the present invention. In the receiver 1 of this example, a discharge path with a spark gap interposed is formed in its antenna circuit portion. As shown in the figure, a line 3 connecting the antenna input terminal electrode 41 and the anode of the varactor diode 11
1 and a line 32 connecting the other antenna input terminal electrode 42 and the anode of the varactor diode 12, a first spark gap 33 is formed. Moreover, between the line 31 and the positive electrode 40b of the battery 40,
A second spark gap 34 is formed. Similarly, there is a third line between the other line 32 and the positive electrode 40b.
A spark gap 35 is formed.

In this example configured as described above, if static electricity enters the receiver circuit from one of the middle clasps 7R or 7L while the middle clasp 7 is removed, the other middle clasp 7L or 7R will be damaged. If it is grounded, dielectric breakdown occurs in the first spark gap 33 and the gap becomes electrically conductive. As a result, a discharge path is formed from one antenna to the other antenna which is grounded via this first spark gap 32. Alternatively, the second and third spark gaps 3
Dielectric breakdown occurs at 4 and 35, and conduction occurs between these gaps, forming a discharge path from one antenna to the back cover 2b or battery 40 side via these spark gaps 34 and 35. be done. Therefore, static electricity that has entered the circuit can be prevented from entering the RF amplifier circuit 18 side.

When the middle clasp 7 is fastened, static electricity that has entered from there flows to the back cover 2b or the battery 40 side via the second or third spark gap 34, 35. Therefore, static electricity does not cause circuit damage or malfunction.

On the other hand, if static electricity enters the circuit from the side of the back cover 2b, the static electricity will move in the opposite direction to the second
The spark flows through the third spark gaps 34 and 35 and is discharged from the inner fastener 7 to the outside. In this case as well, damage to the circuit or malfunction due to static electricity can be prevented.

Here, in this example, the second and third
spark gaps 34, 35 are formed between the lines 31, 33 and the battery positive electrode 40b. Instead of this, lines 31, 3 are shown as dashed lines in the figure.
3 and the negative electrode 40a of the battery.

Method of Forming Spark Gap Each of the above spark gaps can be formed as follows. In the following description, the first spark gap will be explained as an example, but unless otherwise specified, the second and third spark gaps can be formed in the same way.

First, as shown in FIG. 12, the first spark gap 33 includes a surface electrode pattern 46a connected to each antenna portion 5R, 5L on a circuit board 46 constituting the circuit block 4 of the receiver. What is necessary is to set the shape of 46b. That is, forming steeple-shaped portions 47a and 47b facing each other in a part of these patterns,
These intervals L may be set so that discharge starts at a target voltage.

It is preferable that the spark gap of this configuration is formed at the end of the circuit board 46 because the influence on other components on the board can be reduced.

When the circuit board 46 has a multilayer structure, the first spark gap 32 can be formed between the two stacked layers. That is, in FIG. 13, the circuit board 46 sandwiches the insulating layer 461,
In the case where the conductor layer 462 and the conductor layer 463 are laminated, the spire portion 46 projects vertically, respectively.
By forming 2a and 463a, a spark gap can be formed. Each conductor layer 462, 4
63 are connected to the sides of each antenna portion 5R, 5L, respectively. When this configuration is adopted, almost no space on the substrate surface is required for forming the spark gap, so there is an advantage that the mounting efficiency of the circuit board does not decrease.

Next, in the case of a multilayer circuit board, a spark gap can be formed using the through holes formed therein. For example, as shown in FIG. 14, the electrode pattern 52 of the conductive layer stacked on the upper surface side of the through hole 51 is set in the shape of a spire toward the through hole 51 side. Similarly, the electrode pattern 53 of the conductive layer laminated on the lower surface side of the through hole 51 is also set in the shape of a spire toward the through hole 51 side. With this setting, a spark gap is formed between these spire-shaped electrode patterns.

[0040] The spark gap can then also be arranged on the side portions of the substrate. In FIGS. 15 and 16,
An example of this is shown. In these figures, the antenna input terminal electrode plate 41 (42) is formed with a vertical portion 411 that faces the side surface of the circuit board 46, and this portion includes a protruding portion that protrudes toward the side surface of the circuit board. 412 is formed. On the side surface of the circuit board facing this protrusion 412, an electrode pattern 461 connected to the positive or negative electrode of the circuit is exposed. Note that 462 is an insulating plate for holding down the substrate. In this configuration, the protrusion 4
A spark gap is formed between 12 and electrode pattern 461.

On the other hand, second and third spark gaps 34, 3 formed between the back cover 2b and the antenna 7 side
5 can be arranged as follows. That is, Figure 1
7, input terminal 6R of antenna 5R (5L)
(6L) and the back cover 2b facing this, protrusions 61 and 71 may be formed, respectively, in the direction of approaching each other. Arranging the spark gap at such a position has the advantage that the degree of freedom in designing the board pattern increases compared to the case where the spark gap is arranged on the circuit board.

Here, if the case 2a is made of a conductive material, a spark gap can be formed between the antenna input terminals 6R, 6L and the side of the case 2a through which they pass. That is, as shown in FIG.
A spark gap is formed between the terminal 6R and the case 2a in which this through hole is formed.

(Third Embodiment) FIG. 19 shows still another embodiment of the present invention. The example shown in the figure is antenna 5
The circuit configuration is such that the spark gap 33 formed between R and 5L is connected to the back cover 2b via a dedicated wiring pattern 81 that is independent of the power supply pattern and ground pattern in the receiver circuit. There is. In the illustrated example, the back cover 2b is connected to the positive electrode 40b of the battery 40 via a wiring pattern 82, and a dedicated wiring pattern 81 is connected to this wiring pattern 82. Note that if the case 2a is made of a conductive material, this wiring pattern 81 may be connected to the case 2a side. Further, when the back cover 2b or the case 2a is connected to the negative electrode 40a of the battery, a dedicated wiring pattern 81 may be connected to the wiring portion connecting these.

[0044] Even if the circuit configuration thus constructed is adopted, the same effects as in the second embodiment described above can be obtained.

Next, in the above example, in order to ensure separation between the receiver circuit 4 side and the electrostatic discharge path (wiring patterns 81, 82) side, as shown in FIG. It is preferable to interpose a decoupling circuit 83 between them. As the decoupling circuit 83, the circuit configurations shown in FIGS. 21 to 24 can be adopted. Note that, as shown in FIG. 25, even when the back cover 2b (or case 2a) is electrically separated from the battery 40 side, there is a spark gap 33 between the loop antenna 5 and the back cover 2b. A discharge path can be formed.

(Other Embodiments) The above embodiments are cases in which the present invention is applied to a wristwatch type receiver. However, the present invention can be similarly applied to other wrist-worn radios. For example, it goes without saying that the present invention can also be applied to a wrist-worn radio device having a transmitting function.

In each of the above examples, the case where the back cover, which is a conductive member that comes into contact with the arm, is connected to the positive side electrode of the circuit has been mainly explained, but when it is connected to the negative side electrode of the circuit, Of course, the same effect can also be obtained.

[0048]

[Effects of the Invention] As explained above, in the wrist-worn radio device of the present invention, the portion made of the conductive member that can be contacted with the human body when worn is set to the AC ground potential of the built-in radio device circuit. There is. Therefore, according to the present invention, when the device is worn on the arm, the case back cover, inner clasp member, etc. made of a conductive member are set to the AC ground potential of the radio circuit. Therefore, even if these conductive parts come into contact with the human body,
It is possible to avoid deterioration of characteristics such as receiving sensitivity caused by contact with the human body, which has an adverse electrical effect on the radio circuit.

Furthermore, in the wrist-worn radio device of the present invention, when worn on the wrist, an antenna tuning circuit having a capacity that resonates with the loop antenna incorporated in the arm band to form a tuning circuit thereof is provided. Connect the constituent circuit elements to the positive or negative electrode of the radio circuit, thereby
A static electricity discharge path is formed between the clasp member and the electrode via this circuit element. Therefore, according to the invention:
When static electricity enters the loop antenna side from the clasp part due to contact with the human body side, the static electricity that has entered is discharged to the ground side via the discharge path including this circuit element. Therefore, it is possible to eliminate problems such as damage to the radio circuit or malfunction caused by static electricity entering from the human body side. Furthermore, since the discharge path formed in this way does not have a configuration in which a separate circuit element is added for that purpose, the capacity of the antenna tuning circuit does not change, and therefore, it has the advantage that it does not cause fluctuations in antenna characteristics. .

Furthermore, in the wrist-worn radio device of the present invention, a discharge path for static electricity that has entered from the human body is configured via a spark gap. By employing this configuration, it is also possible to avoid the negative effects of static electricity entering from the human body entering the circuits and damaging them or causing them to malfunction.

[Brief explanation of the drawing]

FIG. 1 is an external view showing a wristwatch type receiver to which the present invention is applicable.

FIG. 2 is a longitudinal sectional view of the wristwatch-type receiver of FIG. 1;

FIG. 3 is a circuit diagram showing a conventional antistatic circuit configuration.

FIG. 4 is a schematic block diagram showing the circuit configuration of main parts of the first embodiment of the present invention.

FIG. 5 is a schematic block diagram showing a discharge path of static electricity in the embodiment shown in FIG. 4;

FIG. 6 is a schematic block diagram showing a static electricity discharge path in the embodiment shown in FIG. 4;

FIG. 7 is a schematic block diagram showing a modification of the embodiment shown in FIG. 4;

FIG. 8 is a schematic block diagram showing a modification of the embodiment shown in FIG. 4;

FIG. 9 is a schematic block diagram showing a modification of the embodiment shown in FIG. 4;

FIG. 10 is a schematic block diagram showing a modification of the embodiment shown in FIG. 4;

FIG. 11 is a schematic block diagram showing the circuit configuration of main parts in a second embodiment of the present invention.

12 is an explanatory diagram showing an example of formation of a spark gap in the embodiment of FIG. 11. FIG.

13 is an explanatory diagram showing an example of formation of a spark gap in the embodiment of FIG. 11. FIG.

14 is an explanatory diagram showing an example of formation of a spark gap in the embodiment of FIG. 11. FIG.

15 is a partial perspective view showing an example of formation of a spark gap in the embodiment shown in FIG. 11. FIG.

16 is a partial cross-sectional view showing the configuration of FIG. 15. FIG.

17 is a partial perspective view showing an example of formation of a spark gap in the embodiment shown in FIG. 11. FIG.

18 is a partial perspective view showing an example of formation of a spark gap in the embodiment shown in FIG. 11. FIG.

FIG. 19 is a schematic block diagram showing main circuit parts in a third embodiment of the present invention.

FIG. 20 is a schematic block diagram showing a modification of the embodiment of FIG. 19;

FIG. 21 is a circuit diagram showing an example of a decoupling circuit in the embodiment of FIG. 20;

FIG. 22 is a circuit diagram showing an example of a decoupling circuit in the embodiment of FIG. 20;

FIG. 23 is a circuit diagram showing an example of a decoupling circuit in the embodiment of FIG. 20;

24 is a circuit diagram showing an example of a decoupling circuit in the embodiment of FIG. 20. FIG.

25 is a schematic block diagram showing a modification of the embodiment of FIG. 19; FIG.

Claims (13)

[Claims] Claim 1: A wrist-mounted radio device comprising a radio device body and an arm band attached to the radio device body,
What is claimed is: 1. A wrist-worn radio device, characterized in that it has a part made of a conductive member that can come into contact with a human body when it is worn, and the part made of the conductive member is set to an AC ground potential of a built-in radio circuit. 2. The wrist-worn radio device according to claim 1, wherein the portion made of the conductive member is at least one of a case of the radio device main body and a case back cover. 3. According to claim 1 or 2, the portion made of the conductive member is set to the AC ground potential by directly or indirectly connecting it to the ground electrode of the radio circuit. Features a wrist-worn radio. 4. In claim 1, the arm band comprises:
A pair of band parts with built-in antenna parts formed from a conductive material are connected to each other when worn on the wrist, and the built-in antenna parts are electrically connected to each other to form a loop antenna. A balanced circuit part is configured in the radio circuit by the loop antenna, and the part made of the conductive member is provided with a substantially neutral part in the balanced circuit part. 1. A wrist-worn radio device, characterized in that the AC ground potential is set by connecting to a point. 5. The arm-mounted radio according to claim 4, wherein the portion made of the conductive member is at least one of a case and a case back of the radio main body. 6. The wrist-worn radio device according to claim 4, wherein the middle retaining member is connected to a substantially neutral point position in the balanced circuit portion. 7. A radio device comprising a radio device body with a built-in radio circuit, an arm band attached to the radio device body, and an antenna that is incorporated into the arm band and forms a loop antenna when worn on the arm. , the arm band includes a pair of band parts each attached to the radio device main body side, an antenna part built into these band parts, and these antenna parts are electrically connected to form the loop antenna. In a wrist-worn radio device, the radio device is connected in parallel to the loop antenna, and has a capacitance that resonates with the loop antenna to form a tuning circuit thereof. a circuit element constituting an antenna tuning circuit, the circuit element being connected to the positive or negative electrode of the radio circuit, and connecting the middle member and the electrode via the circuit element. A wrist-worn radio device characterized in that a static electricity discharge path is formed in the arm. 8. In claim 7, the circuit element having a capacitance constituting the antenna tuning circuit is composed of a pair of varactor diodes connected in series facing each other, and the midpoint between these varactor diodes is , a wrist-worn radio device, characterized in that it is connected to the positive or negative electrode of the radio circuit. 9. According to claim 7 or 8, at least one of the case and the case back of the radio device main body is formed of a conductive member, and the conductive member is connected to a positive or negative electrode of the radio device circuit. A wrist-worn type wireless device, wherein a discharge path for static electricity is formed between the inner fastening member and the conductive member, which are connected to each other via the circuit element. 10. The arm band includes a radio main body and an arm band attached to the radio main body, and the arm band includes a pair of band parts in which an antenna component made of a conductive material is built-in, and an arm band. In the wrist-worn type wireless device, the above-mentioned wrist-worn radio device is provided with a conductive middle member that connects these band portions to each other when worn and electrically connects built-in antenna components to each other to form a loop antenna circuit. A wrist-worn radio device characterized in that the loop antenna circuit includes an electrostatic discharge path formed through a spark gap. 11. The wrist-mounted radio according to claim 10, wherein the spark gap is formed between terminals of the pair of antenna parts on the side of the radio main body. 12. In claim 10, the spark gap is formed between the antenna component and a positive or negative electrode side of a power source of a radio circuit built in the radio main body. Features a wrist-worn radio. 13. The antenna component according to claim 10, further comprising a portion made of a conductive member that can come into contact with a human body when worn, and the spark gap is formed between the portion made of the conductive member and the antenna component. A wrist-worn radio device characterized by: