JPH0787541A - Wrist watch radio receiver - Google Patents

Abstract

PURPOSE:To obtain a wrist watch type radio receiver by which excellent reception sensitivity can be obtained even in any state that a band shaped antenna is connected or is opened. CONSTITUTION:This receiver is provided with band shaped antenna loading/ unloading detection means 20a and 20b detecting the loading/unloading state of an electric connection part 21 and a control means 31 controlling the impedance set values of impedance matching circuits 30 and 32. Therefore, the impedance matching can be obtained in any state at the time of connecting or opening a band shaped antenna and excellent reception sensitivity can be always obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrist watch comprising a band-shaped antenna which is detachably divided into two parts through an electric connection part, and a receiver main body having an impedance matching circuit for the band-shaped antenna. Type wireless receiver.

[0002]

2. Description of the Related Art A wristwatch type small radio receiver as shown in FIG. 4 has been developed as a wristwatch type radio receiver, for example, a pager in a paging system which is a kind of mobile communication system. In the figure, 1 is a receiver main body having a clock function, and the receiver main body 1 is provided with antenna members 4a and 4b formed in bands 3a and 3b via lead members 2a and 2b formed of conductors. It is electrically connected.

Inside the respective bands 3a, 3b, antenna members 4a, 4b formed of a flexible conductor are integrally arranged. In addition, a hook metal fitting 5 is fixed to the end portion of the band 3a, and a position-adjustable metal fitting 6 is fitted in a semi-fixed state on the end portion side of the one band 3b. The metal fitting 6 can be moved according to the thickness of the wearer's wrist, and is engaged with the hook metal fitting 5 to fix the receiver body 1 to the wrist when the metal fitting is worn.

At the end of the band 3a on which the hook fitting 5 is attached, a metallic protruding terminal 7 fixed to the antenna member 4a is provided so as to project to the back side of the band 3a. Further, a plurality of engaging holes 8, 8 ... Engaging with the projecting terminal 7 are formed on the end side of the band 3b.

The receiver body 1 is provided with a liquid crystal panel 9 for displaying a received message and the like, a speaker 10 for giving a voice notification of the presence or absence of the reception, and the like. In the interior of the receiver body 1, as shown in FIG. 5, an impedance matching circuit 11 connected to the antenna members 4a and 4b,
An RF amplifier (high frequency amplifier) 12 and the like are provided. A trimmer capacitor 13 is provided in the impedance matching circuit 11 connected to the antenna member 4b, and the trimmer capacitor 13 is adapted to engage with the projecting terminal 7 according to the thickness of the wrist of the person wearing the receiver body 1. When the engaging hole 8 at any position is selected, the impedance of the antenna can be finely adjusted according to the change in the radius of the loop antenna R.

When the hook fitting 5 and the fastening fitting 6 are engaged with each other in order to mount the receiver main body 1 on the wrist, the protruding terminal 7 of the antenna member 4a is fitted into the engaging hole 8 at a predetermined position. As a result, as shown in FIG.
The loop antenna R is formed by electrically connecting a and 4b. The impedance matching circuit 11 is for impedance matching between the loop antenna R and the RF amplifier 12.

When the magnetic field component of the transmitted radio wave enters the loop antenna R, a high frequency current is induced in the loop antenna R, and the induced current is reflected after passing through an impedance conversion circuit and a reactance canceling circuit which constitute the impedance matching circuit 11. In the so-called matching state in which the loss is minimized, the loss is sent to the RF amplifier 12 without being attenuated, amplified, and then supplied to a demodulation circuit (not shown). Therefore, the antenna members 4a and 4b
With the loop antenna R formed, it is possible to obtain good reception sensitivity. The loop antenna R and the impedance matching circuit 11 have a selectivity Q at the reception frequency. Here, in the tuning circuit (parallel resonance circuit), the selectivity Q is represented by Q = f0 / B, where f0 is the resonance point and B is the bandwidth.
When is high, only the signal component is amplified and the other frequency components are attenuated.

By the way, since such a wristwatch type radio receiver is usually used by being worn on the wrist, the impedance matching circuit 11 has the loop antenna with the antenna members 4a and 4b connected as described above. The constant is set according to the state in which R is formed.

[0009]

However, even with a wristwatch type radio receiver, it is sufficiently assumed that the wristwatch type radio receiver is used on a table or the like by removing it from the wrist, or is carried in a pocket. It Then, in that case, the hook fitting 5 of the band 3a and the fastening fitting 6 of the band 3b are disengaged, that is, the electrical connection between the antenna members 4a and 4b is cut off. In general, the loop antenna R is not formed in this state. Therefore, the constant of the impedance matching circuit 11 set in accordance with the state in which the loop antenna R is formed becomes unsuitable in the situation where the antenna members 4a and 4b are not connected, and reflection loss and the like increase, so that the antenna member 4a and There was a drawback that the loss of the current induced in 4b was increased and the high frequency current sent to the RF amplifier 12 was attenuated. Therefore, band 3
When a and 3b are opened, the reception sensitivity of the wireless receiver may be significantly reduced, and the calling number or message transmitted may not be normally received.

Therefore, the present invention has been made in order to solve the above-mentioned problems, and it is a wristwatch capable of obtaining good reception sensitivity regardless of whether the band-shaped antenna is connected or opened. An object of the present invention is to provide a type wireless receiver.

[0011]

The means of the present invention are as follows. That is, in order to solve the above-mentioned problems, the wristwatch type radio receiver according to the present invention includes a band-shaped antenna that is detachably divided into two parts via an electrical connection part, and a signal processing connected to the band-shaped antenna. A band-shaped antenna attachment / detachment detecting means for detecting the attachment / detachment state of the electrical connection part, and a receiver body provided with an impedance matching circuit for impedance matching with a circuit, and the attachment / detachment detecting means. And a control means for controlling the impedance set value in the impedance matching circuit based on the detection signal.

[0012]

According to the wristwatch type radio receiver of the present invention, the band-shaped antenna attachment / detachment detection means (for example, a device for detecting the connection / disconnection state of the connection state detection line of the band-shaped antenna) is connected via the electrical connection portion. Detecting the attachment / detachment state of the band-shaped antenna divided into two parts, and sending the detection signal from the detection means to the control means (eg, switching transistor) to appropriately control the impedance setting value in the impedance matching circuit (eg, , Applying a reverse voltage to the varicap diode based on the detection signal and changing the constant of the impedance matching circuit by the change of its capacitance), in both the connection state and the open state of the band antenna. Also, good reception sensitivity can be obtained.

[0013]

EXAMPLES Examples will be described below with reference to FIGS. FIG. 1 is a front view showing a schematic configuration of a wristwatch type wireless receiver according to the present invention, and FIG. 2 is an implementation of an impedance matching circuit and a control circuit applied to the wristwatch type wireless receiver according to the present invention. It is a circuit diagram which shows an example.

The same components as those shown in FIG. 4 will be described with the same reference numerals. In FIG. 1, 1 is a radio receiver main body, and 3a and 3b are bands attached to the radio receiver main body 1. The outer skin of each of the bands 3a and 3b is formed of synthetic resin or the like, and antenna members 4a and 4b made of a flexible conductor are integrally embedded on the right side inside thereof, one end of which is a metal lead member. 2a,
It is electrically connected to the internal circuit of the receiver body 1 via 2b. In addition, on the left side inside the bands 3a and 3b, the antenna connection state detection line 20 composed of a flexible conductor is provided.
a and 20b are provided, and one end thereof is electrically connected to a circuit inside the receiver main body 1 via metal lead members 2a and 2b.

A hook metal fitting 5 is provided at an end of the band 3a, and a metal protruding terminal 7 and a protruding antenna connecting state detecting terminal 21 are connected to the antenna member 4a and the antenna connecting state detecting wire 20a. Is fixed. On one end side of the one band 3b, a metal fitting 6 is fitted in a semi-fixed state so that the position can be adjusted, and engages with the projecting terminal 7 and the projecting antenna connection state detecting terminal 21. A plurality of dowel holes 8, 8 ... And 22, 22 ... Are bored at predetermined intervals. Incidentally, these engaging holes 8, 8 ...
.. and 22, 22, ... Denote the projecting terminal 7 and the antenna member 4b, and the antenna connection state detecting terminal 2
1 and the antenna connection state detection line 20b are electrically connected to each other, and the antenna member 4 of the band 3b is used.
It may be formed only on a portion covering b or the like, or may be formed so as to penetrate the antenna member or the like.

The receiver main body 1 is provided with a liquid crystal panel 9 for displaying received messages and the like, a speaker 10 for giving a voice notification of the presence or absence of reception, and the like. In addition, as shown in FIG. 2, the antenna member 4 is provided inside the receiver body 1.
impedance matching circuits 30, 32 connected to a and 4b
An antenna connection state detection terminal 21 connected to the antenna connection state detection lines 20a and 20b, an impedance control circuit 31, an RF amplifier 12, a battery (not shown), and the like are provided. A trimmer capacitor VC is provided in the impedance matching circuit 32 connected to the antenna member 4b, and the trimmer capacitor VC is engaged at an appropriate position to engage with the protrusion 7 according to the thickness of the wrist of the person wearing the receiver body 1. When the hole 8 is determined, the impedance of the antenna can be finely adjusted according to the change in the radius of the loop antenna R.

Further, a switching transistor 33 is provided in the impedance control circuit 31 connected to the antenna connection state detection line 20a, and a collector terminal of the switching transistor 33 is provided with a resistor through a resistor.
The power supply voltage Vcc is supplied, and the output voltage from the switching transistor 33 is supplied to the impedance matching circuit 30.
A reverse voltage is applied between the terminals of a varicap diode (variable capacitance diode) 35 disposed inside the terminal, and a terminal corresponding to the magnitude of the reverse voltage due to a change in the width of the depletion layer in the varicap diode 35. Inter-capacity can be obtained. That is, the antenna connection state detection line 20
a and 20b are protrusion-shaped antenna connection state detection terminals 21
When electrically connected with the engaging hole 22 by the engaging hole 22, the base terminal of the switching transistor 33 is grounded, the switching transistor 33 is turned off, and the collector terminal is connected through the resistor 34. A predetermined reverse voltage is applied to the varicap diode 35.

For example, when the characteristic curve of the varicap diode 35 is as shown in FIG. 3 and the reverse voltage applied between the terminals of the varicap diode 35 is 2 volts, the inside of the varicap diode 35 is A change in the depletion layer of the above-mentioned capacitor gives a capacitance of about 12 pF. Therefore, the steady-state constants of the capacitor in parallel with the varicap diode 35 in the impedance matching circuit 30 and the trimmer capacitor VC in the impedance matching circuit 32 are set to the bands 3a and 3b.
Is opened (that is, the antenna connection state detection line 20)
a and 20b are in a non-contact state) and the antenna members 4a and 4b are connected to form the loop antenna R (that is, the antenna connection state detection lines 20a and 20b are connected). Optimum impedance matching circuit 30 for antenna impedance matching
The capacitance of the varicap diode 35 therein is calculated in advance in relation to the constants of other capacitors. Then, by applying a reverse voltage (for example, 2 V) capable of obtaining the inter-terminal capacitance (for example, 12 pF) of the varicap diode 35 that conforms to the constant, between the terminals of the varicap diode 35, the band 3a, Optimal impedance matching can be achieved both in the state in which 3b is opened and in the state in which the bands 3a and 3b are connected and the loop members R are formed by the antenna members 4a and 4B.
Unlike the conventional case, even when the band is opened, the reception sensitivity is not significantly lowered, and it is possible to always perform good reception.

The high frequency current impedance-matched by the impedance matching circuit 30 is amplified by the RF amplifier 12 and sent to a demodulation circuit (not shown). More than,
1 is a schematic configuration of an embodiment of a wristwatch type radio receiver according to the present invention, and its operation will be described below. First, a state in which the bands 3a and 3b are opened, that is, the receiver body 1 is placed on a table or the like without being worn on the wrist and used or put in a pocket or the like and carried is described.

In this case, the antenna connection state detection line 2
The protruding terminal 21 connected to the terminal 0a and the antenna connection state detection line 20b are in an electrically non-contact state. Therefore, the power supply voltage Vcc is supplied to the base terminal of the switching transistor 33 of the impedance control circuit 31 in FIG. 2, the switching transistor 33 is turned on, and the reverse voltage applied to the varicap diode 35 of the impedance matching circuit 30 is Since it is 0 volt, the varicap diode 35 has a capacitance of about 17 pF based on the characteristic curve of FIG. 3, but the impedance matching circuits 30 and 32 in the steady state have the bands 3a and 3b opened as described above. Since the constant is set so that the optimum impedance matching is performed according to the state, even if the antenna members 4a and 4b are not connected and the loop antenna R is not formed, the reception sensitivity is different from the conventional one. Good reception of transmitted radio waves without significant deterioration Rukoto can.

Next, the case where the wristwatch type radio receiver is worn on the wrist will be described. In this case, the hook metal fitting 5 is engaged with the fastening metal fitting 6 in the same manner as when wearing a normal wristwatch, but the hook metal fitting 5 is adjusted when the position of the fastening metal fitting 6 is adjusted according to the wrist of the wearer. The fastener 6
, The protruding terminal 7 and the protruding antenna connection state detection terminal 21 are fitted into either of the engaging elements 8 and 22 to connect the antenna members 4a and 4b and the antenna connection state detection lines 20a and 20b. Make an electrical connection. Further, since the radius of the loop antenna R formed by the antenna members 4a and 4b changes depending on the selected positions of the engagement holes 8 and 22, fine adjustment of impedance matching is also performed in advance by the trimmer capacitor VC in the impedance matching circuit 32. Need to be kept.

Then, as described above, the antenna connection state detection lines 20a and 20a are connected via the antenna connection state detection terminal 21.
When 0b is connected, the base terminal of the switching transistor 33 of the impedance control circuit 31 is grounded,
The switching transistor 33 is turned off.
As a result, the power supply voltage supplied to the collector terminal of the switching transistor 33 becomes, for example, about 2 volts due to the voltage drop of the resistor 34, and the reverse voltage of 2 volts is applied to the varicap diode 35 of the impedance matching circuit 30. To be done. Therefore, as shown in the characteristic curve of FIG. 3, a capacitance of about 12 pF is induced in the varicap diode 35 with respect to the reverse voltage (2 V), and the capacitance of the varicap diode 35 is reduced. Due to the change, the constant of the impedance matching circuit 30 also changes, and the impedance matching state of the loop antenna R formed by the connection of the antenna members 4a and 4b is optimized. Therefore, even when the receiver main body 1 is worn on the wrist, that is, the bands 3a and 3b are connected and the loop antenna R is formed by the antenna members 4a and 4b, good reception sensitivity can be obtained. still,
As described above, the state in which the bands 3a and 3b are opened,
Alternatively, in either case of being connected, the high-frequency current impedance-matched by the impedance matching circuit 30 is amplified by the RF amplifier 12 and then sent to the demodulation circuit for processing, and the received message or the like is received. It is controlled so as to be displayed on the liquid crystal panel 9 of No. 1 and to notify the presence or absence of reception by the voice of the speaker 10.

As described above, according to the wristwatch type radio receiver according to the present invention, the bands 3a and 3b are opened, and the bands 3a and 3b are connected to the antennas 4a and 4b.
Impedance matching is achieved both in the state where the loop antenna R is formed by b and it is possible to always obtain good reception sensitivity. That is, the wristwatch type radio receiver according to the present invention can transmit radio waves regardless of whether it is worn on the wrist, used on a table or the like, or carried in a pocket or the like. It is suitable as a pager for a paging system, etc., which can receive excellent reception quality and which is always required to have high reception sensitivity.

In the present embodiment, the receiver main body 1 is provided with the liquid crystal panel 9 and has a digital clock function. However, the receiver main body 1 is not limited to this and has an analog clock function. May be. Further, in this embodiment, the band 3a, 3
Antenna connection state detection line 2 consisting of a conductor arranged in b
0a, 20b is used to detect the presence or absence of electrical connection of the protruding antenna connection state detection terminal 21 connected to the antenna connection state detection line 20a with the engagement hole 22, but instead of this, For example, a micro switch or the like may be arranged at an appropriate position of the hook fitting 5 or the like to detect the on / off state thereof. Further, in this embodiment, the case where the switching transistor 33 is used as the control means of the impedance matching circuit and the impedance matching is achieved by the change of the reverse voltage to the varicap diode 35 accompanying the ON / OFF of the switching transistor 33 has been described. However, CPU is not limited to this
Alternatively, the control may be performed using a one-chip microcomputer or the like. Further, in the above-described embodiment, the steady state constants of the impedance matching circuits 30 and 32 are set to the band antenna 3.
The impedance matching circuit 30 is set according to the open state of a and 3b, and when the loop antenna R is formed by connecting the bands 3a and 3b to each other, the impedance matching circuit 30 is set.
In the above description, the constant is set to the optimum state. However, by changing the circuit configuration, the constants of the impedance matching circuit 30 in the steady state are connected to the antenna members 4a and 4b to form the loop antenna R. When the band 3a, 3b is opened and the connection of the antenna members 4a, 4b is opened, the control means sets the constant of the impedance matching circuit 30 to the optimum state. You can also

[0025]

As described above, according to the wristwatch type radio receiver of the present invention, the band-shaped antenna attachment / detachment detection means (for example, a device for detecting the connection / disconnection state of the connection state detection line of the band-shaped antenna). Detects the attachment / detachment state of the band-shaped antenna divided into two via the electrical connection part, and outputs the detection signal from the detection means to the control means (for example,
The impedance setting value in the impedance matching circuit by controlling the impedance setting value in the impedance matching circuit (for example, applying a reverse voltage to the varicap diode based on the detection signal and changing the capacitance of the varicap diode. Is changed), there is an excellent effect that good reception sensitivity can be obtained in both states of connection and open of the band-shaped antenna.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a wristwatch-type wireless receiver according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an example of a circuit in a wristwatch type wireless receiver according to an embodiment of the present invention.

FIG. 3 is a graph showing characteristics of a varicap diode used in a wristwatch type wireless receiver according to an embodiment of the present invention.

FIG. 4 is a front view showing a schematic configuration of a conventional wristwatch type wireless receiver.

FIG. 5 is a circuit diagram showing a circuit in a conventional wristwatch type wireless receiver.

[Explanation of symbols]

1 receiver body 2a, 2b, 2c, 2d lead member 3a, 3b band 4a, 4b antenna member 5 hook metal fitting 6 fastening metal fitting 7 projecting terminal 8 engaging hole 9 liquid crystal panel 10 speaker 11 impedance matching circuit 12 RF amplifier (high frequency Amplifier) 13 Trimmer capacitors 20a, 20b Antenna connection state detection line (band-shaped antenna attachment / detachment state detection means) 21 Projected antenna connection state detection terminal 22 Engagement hole 30 Impedance matching circuit 31 Impedance control circuit (control means) 32 Impedance Matching circuit 33 Switching transistor 34 Resistor 35 Varicap diode (variable capacitance diode) VC Trimmer capacitor

Claims (1)

[Claims] 1. A reception provided with an impedance matching circuit for performing impedance matching between a band-shaped antenna which is detachably divided into two parts through an electrical connection part and a signal processing circuit which is connected to the band-shaped antenna. A wristwatch-type wireless receiver including a main body of the device, wherein the attachment / detachment detection means of a band-shaped antenna for detecting the attachment / detachment state of the electrical connection portion, and the impedance matching circuit based on a detection signal from the attachment / detachment detection means. A wristwatch-type wireless receiver, comprising: