JPH08330826A - Arm-mounted type portable radio equipment - Google Patents

Abstract

PURPOSE: To prevent the deterioration of a characteristic owing to the invasion of static electricity occurring by contact with a human body in a watch-type portable radio machine. CONSTITUTION: A loop antenna is constituted by connecting a pair of antenna boards 5a and 5b in the watch-type portable radio equipment by an inside clamping ring 4. The tuning circuit of the antenna is formed by a pair of varactor diodes 10 and 11 which are connected to the loop antenna in parallel. The middle point of the varactor diode is connected to the positive electrode of the power battery 8 in the radio machine through a resistor 16, and it is electrically connected to a back cover 2 consisting of a conductive member. Furthermore, the antenna board 5a is electrically connected to the back cover 2 consisting of the conductive member which is set to the positive potential of power voltage through a resistor 17 at an intersection point with a capacitor 9a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wristwatch type portable radio device for preventing characteristic deterioration due to intrusion of static electricity generated by contact with a human body.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Examined Patent Publication No. 04-227301, a back cover made of a conductive member which can contact a human body when worn on an arm is electrically connected to a middle point of a varactor diode forming an antenna tuning circuit. The discharge path via the varactor diode was formed by setting them to the positive or negative potential of the power supply.

FIG. 1 and FIG. 2 show an example of a wristwatch type portable wireless device having such a structure. The main body of the portable wireless device includes a case body 1 and a back cover 2, and at least the back cover 2 is formed of a conductive member. A power supply battery (not shown) is attached inside the case 1 and is electrically connected to the back cover 2.

Antennas made of conductor plates are respectively incorporated in a pair of wrist-fitting bands 3a and 3b, and the antennas can be connected to each other by means of inner clasps 4 so that they can be attached to the arm. Configure.

FIG. 2 is a schematic block diagram showing the structure of a wristwatch type portable radio device. A pair of antenna plates 5a and 5b incorporated in a band are connected to a radio device circuit 7 via an antenna tuning circuit 6. ing. The positive electrode of the power supply battery 8 is electrically connected to the conductive back cover 2.

FIG. 3 is a circuit diagram showing a static electricity countermeasure circuit configuration and a static electricity discharge path in a conventional example. A loop antenna is configured by connecting the pair of antenna plates 5a and 5b with the clasp 4, and a resonant circuit is formed by the pair of varactor diodes 10 and 11 connected in parallel with the loop antenna. Generally, in an antenna tuning circuit, two varactor diodes are used with different polarities because the varactor diode may become conductive in a strong electric field environment. In this example, the cathode sides of the varactor diodes are connected to each other, connected to the positive electrode of the power supply battery 8 of the wireless device via the resistor 16, and further electrically connected to the back cover 2. A tuning frequency control voltage is applied to the anode side of one varactor diode via resistors 14 and 15. DC component cutting capacitors 9a, 9b
And impedance matching coupling capacitor 1
An antenna tuning circuit is configured by 3a and 13b. When such a wristwatch-type portable radio device is worn on the wrist, static electricity may enter the circuit from the back cover 2 and the inner clasp 4 made of a conductive member. The case where static electricity enters from the inner clasp 4 will be described. As shown in FIG. 3, the entered static electricity passes through the antenna plate 5b, the capacitor 9b, the varactor diode 11, the back cover 2, and the human body as shown by the dotted line in the discharge path. Since it is discharged to the outside, it is prevented from invading the wireless device circuit 7 to prevent electrostatic breakdown or malfunction.

[0007]

However, in the wristwatch type portable wireless device having such a structure, the destruction and malfunction of the wireless device circuit itself due to the intrusion of static electricity can be prevented, but the discharge path is formed through the varactor diode. Therefore, some varactor diodes with inferior antistatic properties may be destroyed by static electricity, which may make antenna tuning impossible. Therefore, only a varactor diode having an excellent antistatic property can be adopted, which makes it difficult to optimally design and miniaturize the antenna tuning circuit and causes a cost increase.

Therefore, the present invention solves such a problem, and an object of the present invention is to prevent the deterioration of the characteristics of a wristwatch type portable radio device due to the intrusion of static electricity generated by the contact with the human body. It is therefore an object of the present invention to provide an electrostatic discharge resistant structure which is superior in circuit characteristics to the related art by forming an electrostatic discharge path without passing through a varactor diode of an antenna tuning circuit.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problem of characteristic deterioration due to static electricity, the present invention provides a pair of arm bands attached to a radio main body and a loop incorporated in the arm bands when worn on the arm. A pair of antenna parts forming an antenna, a clasp member capable of electrically connecting these antenna parts to form a loop antenna, and a power source for the radio circuit that can be contacted with the human body side when the arm is worn. A wrist-worn portable wireless device having a conductive member set to a positive or negative potential of a voltage, the first electrically connected between an antenna portion and the conductive portion.
An electrostatic discharge path is formed between the antenna part and the conductive member via the resistance element. The first resistance element is connected to both sides of the pair of antenna portions, respectively.

Further, there is provided a pair of serially connected varactor diodes which resonate with the loop antenna to form an antenna tuning circuit, and a midpoint between the pair of varactor diodes is wirelessly transmitted via a second resistance element. It is desirable that the second resistance element is connected to the positive or negative potential of the electronic circuit and has a resistance value larger than that of the first resistance element.

A control voltage output from the radio device circuit is applied to a midpoint between the pair of varactor diodes via the second resistance element, and the second resistance element is the first resistance element. It is desirable that the resistance value be larger than that.

A pair of arm bands attached to the main body of the radio, a pair of antenna parts incorporated in the arm bands to form a loop antenna when worn on the arm, and these antenna parts are electrically connected. A wrist-worn portable radio having a clasp member capable of forming a loop antenna, and a conductive member that is capable of contacting the human body side in a wrist-worn state and is set to a positive or negative potential of the power supply voltage of the radio circuit. In the device, an electrostatic discharge path is formed between the antenna part and the conductive member through the first resistance element electrically connected between the antenna part and the battery in the portable wireless device and the battery. Is characterized by. The first resistance element is connected to both sides of the pair of antenna portions, respectively.

Further, a pair of varactor diodes connected in series which resonate with the loop antenna to form an antenna tuning circuit is provided, and a radio is provided via a second resistance element at a midpoint between the pair of varactor diodes. A control voltage output from the machine circuit is applied, and it is desirable that the second resistance element has a larger resistance value than the first resistance element.

Further, a pair of arm bands attached to the main body of the radio, a pair of antenna parts incorporated into the arm bands to form a loop antenna when the arm is worn, and these antenna parts are electrically connected. A wrist-worn portable wireless device having a clasp member capable of forming a loop antenna, and a conductive member that can be contacted with the human body side when worn on the arm and is set to a positive or negative potential of the power supply voltage of the wireless device circuit. In, a static discharge path is formed between the antenna portion and the conductive portion via the first resistance element electrically connected between the antenna portion and the conductive portion, and An electrostatic discharge path is formed between the antenna portion and the conductive member via the second resistance element electrically connected to the battery of the portable wireless device and the battery. It is characterized in that is. Also,
It has a pair of varactor diodes connected in series that resonate with the loop antenna to form an antenna tuning circuit, and is output from the radio circuit via a third resistance element at the midpoint between the pair of varactor diodes. A control voltage is applied to the third resistance element, and the third resistance element has a resistance value larger than that of the first and second resistance elements.

If at least one of the case and the back cover of the wireless device is formed of a conductive member, a static electricity discharge path is formed between the conductive member and the antenna portion.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a wristwatch type portable radio device of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 4 shows a circuit configuration of a wrist watch type portable radio device and an electrostatic discharge path according to an embodiment of the present invention. A pair of antenna plates 5a and 5b incorporated in the band
To form a loop antenna, and a pair of varactor diodes 10 and 11 connected in parallel at terminals 12a and 12b form a resonance circuit of the antenna. Further, the direct-current component cutting capacitors 9a and 9b and the impedance matching capacitors 13a and 13b form an antenna tuning circuit. Generally, in an antenna tuning circuit, two varactor diodes whose polarities are changed are used in series because the varactor diode may become conductive in a strong electric field environment. In this example, the cathode sides of the varactor diodes 10 and 11 are connected to each other, and the varactor diodes 10 and 11 are connected to the positive electrode of the power supply battery 8 of the wireless device via the resistor 16 to serve as a reference voltage. It is electrically connected to the back cover 2 made of a member. A tuning frequency control voltage lower than the power supply voltage is applied to the anode side of the varactor diodes 10 and 11 from the wireless device circuit 7 via the resistors 14 and 15, and the capacitance values of the varactor diodes 10 and 11 are changed. It is adjusted to the desired tuning frequency. Further, the antenna plate 5a has a resistor 17 at the intersection with the DC component cutting capacitor 9a.
Is electrically connected to the back cover 2 which is set to the positive potential of the power supply voltage via.

The case of the main body of the portable wireless device may also be made of a conductive material such as stainless steel, in which case it is connected to the positive or negative potential of the wireless device circuit like the case back 2. If the case is formed of a conductive member, the contact portion with the human body increases, and thus the static electricity easily escapes to the outside, and the discharge path of the static electricity is more reliably formed.

Next, the antistatic function in this example will be described. Explaining the case where static electricity enters from the inner clasp 4, as shown in the figure, the entered static electricity is discharged to the outside such as a human body through the antenna plate 5a, the resistor 17 and the back cover 2 as shown by a dotted line in the discharge path. Varactor diode 1
Never pass 0 or 11. Therefore, even a varactor diode, which is inferior in electrostatic resistance, is not electrostatically destroyed. On the contrary, when static electricity enters from the back cover 2, it flows in the opposite direction through the above-mentioned discharge path and is discharged from the clasp 4 to the outside.

Further, the connection of the resistor 17 has an effect of improving the communication characteristic of the wireless device when worn on the wrist, in addition to the countermeasure against static electricity. In this portable wireless device, the middle clasp 4 and the back cover 2 may be electrically connected to each other via the arm when the user wears the arm. is there. The instability of the conduction state affects the charging state of the electric charges of the DC component cutting capacitors 9a and 9b, and there is a possibility that the tuning deviation occurs when the frequency tuning operation is performed at high speed. Antenna plates 5a, 5b
By previously fixing the DC potential of, stable tuning operation can be obtained without being affected by the state of wearing on the arm. If the value of the resistor 17 is too small, it will affect the Q of the resonance of the antenna. Therefore, the resistor 17 has a value of about 5 k to 50 kΩ. It will be easier to follow the path.

(Embodiment 2) FIG. 5 shows a circuit configuration of a wrist watch type portable radio device and an electrostatic discharge path according to an embodiment of the present invention. Since the antenna tuning circuit configuration of the wristwatch type portable wireless device of this example is substantially the same as that shown in FIG. 4, corresponding parts are designated by the same reference numerals.

In this example, the discharge paths through the resistors 17 and 18 which do not pass through the varactor diode are provided on both sides of the antenna plates 5a and 5b incorporated in a pair of bands, respectively. According to this configuration, in a state where the fixing of the clasp 4 is opened and the pair of antenna plates are cut off, the varactor diodes 10, 11 due to the static electricity, the radio circuit, regardless of whether the static electricity invades on either side of the antenna plates 5a, 5b. It is possible to prevent the destruction of 7 and malfunction, and it is possible to take a more reliable countermeasure against static electricity. On the contrary, when static electricity enters from the back cover 2, the static electricity flows through the discharge path in the opposite direction and is discharged from the clasp 4 to the outside.

(Embodiment 3) FIG. 6 shows a circuit configuration of a wrist watch type portable radio device according to an embodiment of the present invention. Since the antenna tuning circuit configuration of the wristwatch type portable wireless device of this example is substantially the same as that shown in FIG. 4, corresponding parts are designated by the same reference numerals.

In the configuration of this example, the anode side of the pair of varactor diodes 10 and 11 of the antenna tuning circuit is common, and the antenna tuning control voltage lower than the power supply voltage is transmitted through the resistor 19 to the pair of varactor diodes 10. 1
It is applied to the midpoint of 1. The value of resistor 19 is resistor 17,
If the value is increased by one digit from the value of 18, the static electricity easily flows through the path of the resistors 17 and 18.

According to this structure, the resistor 1 for connecting the cathode side of the varactor diodes 10 and 11 and the back cover 2 together.
7 and 18 can be made to have the same resistance as the discharge path of static electricity, the resistance for applying the antenna tuning control voltage can be reduced, and the capacitor for cutting the DC component can be deleted.

According to the above structure, not only the destruction and malfunction of the varactor diodes 10 and 11 and the radio circuit 7 due to the invasion of static electricity can be prevented, but also the number of resistors and capacitors can be reduced and the cost can be reduced. In a wristwatch type terminal, which has a limited space to be used, the margin for arranging elements becomes large, and an optimum layout can be performed at high frequencies.

(Embodiment 4) FIG. 7 shows a circuit configuration of a wristwatch type portable radio device according to an embodiment of the present invention. Since the antenna tuning circuit configuration of the wristwatch type portable wireless device of this example is substantially the same as that shown in FIG. 4, corresponding parts are designated by the same reference numerals.

In the configuration of this example, the antenna tuning control voltage applied to the cathode side of the varactor diodes 10 and 11 of the antenna tuning circuit is a positive potential, and the anode side is a resistor 1.
It is set to the negative voltage of the power supply via 7 and 18. The resistance values of the resistors 17 and 18 are preferably smaller than the resistance value of the resistor 19. In order to widen the tuning frequency range and widen the band, the range of the antenna tuning control voltage applied to the varactor diode must be wider than the power supply voltage range, and the boosting operation is required. In that case, a positive voltage may be preferable to a negative voltage in terms of circuit configuration, and the antenna tuning control voltage also becomes a positive voltage, and this configuration is effective.
Further, in this example, capacitors 9a and 9b for cutting direct current components are required to prevent a short circuit of the power supply voltage due to the contact between the back cover 2 and the antenna plates 5a and 5b.

In the above-mentioned structure, the discharge paths of the static electricity having entered from the clasp 4 are the antenna plates 5a and 5b,
It is discharged to the outside such as a human body through the resistors 17 and 18, the power supply battery 8 and the case back 2. On the contrary, when static electricity enters from the back cover 2, it flows in the opposite direction through the above-mentioned discharge path and the inside clasp 4
Is discharged from the outside.

(Embodiment 5) FIG. 8 shows a circuit configuration of a wristwatch type portable radio device according to an embodiment of the present invention. Since the antenna tuning circuit configuration of the wristwatch type portable wireless device of this example is substantially the same as that shown in FIG. 4, corresponding parts are designated by the same reference numerals.

In the configuration of this example, the antenna tuning control voltage applied to the cathode side of the varactor diodes 10 and 11 of the antenna tuning circuit is a positive potential, and the anode side is a resistor 1.
It is set to the negative voltage of the power supply via 7 and 18. A resistor 20 is connected between the antenna part and the back cover 2 to increase the discharge path of the invading static electricity, thereby increasing the certainty of the anti-static effect. The resistance value of the resistors 17, 18 and 20 is the resistance 1
It is desirable that it is smaller than the resistance value of 9. Further, in this example, in order to prevent a short circuit of the power supply voltage due to the contact between the back cover 2 and the antenna plates 5a, 5b, a capacitor 9a for cutting a direct current component,
9b is required. This resistance is applied to the antenna parts 5a and 5b.
It may be connected to both sides of, and this will increase the certainty of the measures against static electricity.

With the above construction, the middle clasp 4 is
The path of static electricity that has entered further is a path from the antenna plate 5a through the resistor 20 to the back cover 2 and a path from the antenna plates 5a and 5b through the resistors 17 and 18 and the power battery 8 to the back cover 2. There are two ways.

(Embodiment 6) FIG. 9 shows a circuit configuration of a wristwatch type portable radio device according to an embodiment of the present invention. Since the antenna tuning circuit configuration of the wristwatch type portable wireless device of this example is substantially the same as that shown in FIG. 4, corresponding parts are designated by the same reference numerals. The configuration of this example shows the case where the back cover 2 made of a conductive member of the portable wireless device is set to a negative potential of the power supply voltage. The back cover 2 of the wristwatch-type portable wireless device may preferably have a negative potential depending on how the reference voltage of the circuit is set. Therefore, the anode side of the varactor diodes 10 and 11 connected to the back cover 2 is also connected to the negative voltage, and the antenna tuning control voltage applied to the cathode side has a positive potential.

With the above-mentioned structure, the discharge path of static electricity that has entered from the clasp 4 is discharged to the outside through the antenna plates 5a and 5b, the resistors 17 and 18, and the back cover 2. On the contrary, when static electricity enters from the back cover 2, it flows in the opposite direction through the above-mentioned discharge path and is discharged from the clasp 4 to the outside.

[0035]

Since the present invention is constructed as described above, it has the following effects.

Since the electrostatic discharge path via the resistor is provided between the antenna portion of the portable radio and the conductive member, the electrostatic discharge path that has entered due to contact with the human body does not pass through the varactor diode. It is possible to prevent destruction of the varactor diode due to static electricity. Therefore, it is possible to use even a varactor diode with poor static resistance characteristics, which can optimize, miniaturize, and reduce the cost of the antenna tuning circuit, and if a varactor diode with a small series resistance is used, the sensitivity can be improved by improving the antenna gain. There is.

Further, by connecting the resistors to both sides of the pair of antenna parts, the circuit can be protected regardless of which side of the antenna plate the invasion of static electricity is, thus providing a more reliable countermeasure against static electricity. it can.

If the antenna tuning control voltage is applied to the middle point of a pair of varactor diodes connected in series in the tuning circuit through a resistor, the number of capacitors and resistive elements can be reduced, which leads to cost reduction and optimum operation. The layout has the effect of optimal circuit operation. Further, if the resistance is set to a resistance value larger than the resistance of the discharge path connected to the antenna portion, the invading static electricity can easily pass through the path of the discharge path, increasing the certainty.

If the case body is formed of a conductive member in addition to the back cover of the portable wireless device, the number of portions in contact with the human body increases, so that the electrostatic discharge path can be formed more reliably.

[Brief description of drawings]

FIG. 1 is an external perspective view of a wristwatch type portable wireless device according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a circuit configuration in an example of the present invention.

FIG. 3 is a circuit diagram showing a conventional static electricity countermeasure circuit configuration and a static electricity discharge path.

FIG. 4 is a circuit diagram showing a circuit configuration and an electrostatic discharge path in the embodiment of the present invention.

FIG. 5 is a circuit diagram showing a circuit configuration and an electrostatic discharge path in the embodiment of the present invention.

FIG. 6 is a circuit diagram showing a circuit configuration in an example of the present invention.

FIG. 7 is a circuit diagram showing a circuit configuration in an example of the present invention.

FIG. 8 is a circuit diagram showing a circuit configuration in an example of the present invention.

FIG. 9 is a circuit diagram showing a circuit configuration in an example of the present invention.

[Explanation of symbols]

 1 ・ ・ ・ Wrist watch type portable radio case 2 ・ ・ ・ Back cover 3a, 3b ··· Band body 4 …… Inner clasp 5a, 5b ··· Antenna plate 6 ・ ・ ・ ・ ・Antenna tuning circuit 7 ... Radio circuit 8 ... Power supply battery 9a, 9b ... Capacitor for cutting DC component 10 ... Varactor diode 11 ... Varactor diode 12a, 12b.・ Terminals 13a, 13b ・ ・ Matching capacitors 14, 15 ・ ・ Resistance for antenna tuning voltage application 16 ・ ・ ・ Resistance 17 ・ ・ ・ Resistance 18 ・ ・ ・ Resistance 19 ・ ・ ・ ・ ・Resistor for applying antenna tuning voltage 20 ... Resistor

Claims (11)

[Claims] 1. A pair of arm bands attached to a radio main body, a pair of antenna parts incorporated in the arm bands to form a loop antenna when the arm is worn, and these antenna parts are electrically connected. A wrist-worn portable radio having an inner clasp member capable of forming the loop antenna, and a conductive member that is capable of contacting the human body side in the arm-worn state and is set to a positive or negative potential of the power supply voltage of the radio circuit. In the machine, an electrostatic discharge path is formed between the antenna part and the conductive member via a first resistance element electrically connected between the antenna part and the conductive part. A wrist-worn portable wireless device characterized by. 2. The wrist-worn portable radio device according to claim 1, wherein the first resistance element is connected to both sides of the pair of antenna portions. 3. The method according to claim 1, further comprising a pair of varactor diodes connected in series that resonate with the loop antenna to form an antenna tuning circuit, and a middle point between the pair of varactor diodes is a first point. The second resistance element is connected to a positive or negative potential of the radio circuit via a second resistance element, and the second resistance element has a resistance value larger than that of the first resistance element. Band radio. 4. The control voltage output from the radio device circuit according to claim 1 or 2, wherein a control voltage output from the radio device circuit is applied to a midpoint between the pair of varactor diodes. The resistance element has a resistance value larger than that of the first resistance element. 5. A pair of arm bands attached to the main body of the radio, a pair of antenna parts which are incorporated in the arm bands to form a loop antenna when worn on the arm, and these antenna parts are electrically connected. A wrist-worn portable radio having an inner clasp member capable of forming the loop antenna, and a conductive member that is capable of contacting the human body side in the arm-worn state and is set to a positive or negative potential of the power supply voltage of the radio circuit. In the machine, an electrostatic discharge path is formed between the antenna part and the conductive member via the first resistance element electrically connected between the antenna part and the battery in the portable radio device and the battery. A wrist-worn portable wireless device characterized by being formed. 6. The wrist-worn portable radio device according to claim 5, wherein the first resistance element is connected to both sides of the pair of antenna portions. 7. The varactor diode according to claim 5 or 6, which has a pair of varactor diodes connected in series and which resonates with the loop antenna to form an antenna tuning circuit. A control voltage output from the wireless device circuit is applied via the second resistance element, and the second resistance element has a resistance value larger than that of the first resistance element. Band radio. 8. A pair of arm bands attached to the main body of the radio, a pair of antenna parts incorporated in the arm bands to form a loop antenna when the arm is attached, and these antenna parts are electrically connected. An arm-mounted mobile phone having a clasp member capable of forming the loop antenna, and a conductive member capable of contacting the human body side in the arm-worn state and set to a positive or negative potential of the power supply voltage of the radio circuit. In the wireless device, via a first resistance element electrically connected between the antenna portion and the conductive portion,
A static discharge path is formed between the antenna portion and the conductive portion, and a second resistance element electrically connected between the antenna portion and the battery of the portable wireless device and the battery. An electrostatic discharge path is formed between the antenna part and the conductive member through the arm mounting type portable radio device. 9. The wrist-worn portable wireless device according to claim 8, wherein the first resistance element is connected to both sides of the pair of antenna portions. 10. A pair of varactor diodes connected in series, which resonate with the loop antenna to form an antenna tuning circuit, according to claim 8 or 9, wherein the pair of varactor diodes is arranged at a middle point. The control voltage output from the radio circuit is applied through the third resistance element, and the third resistance element has a resistance value larger than that of the first and second resistance elements. A wrist-worn radio device. 11. The wrist-worn portable radio according to claim 1, wherein the portion made of the conductive member is at least one of a case and a back cover of the wireless device. Machine.