JPS5853231A - Wristwatch type radio receiver - Google Patents

Abstract

PURPOSE:To incorporate a radio receiver into a wristwatch without changing the conventional form of the wristwatch, by assembling an antenna inductor constituting a high frequency tuning circuit to a watchband. CONSTITUTION:A wristwatch main body 14 is built in with a liquid crystal display part 20 which displays the time, a printed circuit board 21 containing a timepiece circuit LSI, an electric circuit IC of a radio receiver, a tuning varactor, etc., and a variable resistor 10 which produces the voltage to vary the capacity of the varactor. The resistor 10 is turned by a shaft 22. On the other hand, an inductor 7 obtained by winding densely a coil round a magnetic material of ferrite, etc. is adhered fixedly to a connecting metallic parts 16 of a watchband 15 via an insulator 17. Thus a tuning inductor which also serves as an antenna is obtained. The inductor 7 is connected to the electric circuit of the main body 14 via a lead wire 18.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radio receiver built into a wristwatch.

In recent years, wristwatches have changed from conventional mechanical analog displays to electronic digital displays. This is largely due to LSI technology, especially CMO8LSI technology.

Electronic digital watches are superior to conventional mechanical watches in terms of accuracy, price, and functionality. In particular, in terms of functionality, not only has the clock function been diversified, but the melody and sound for alarms have the same pronunciation (speech synthesis L made possible by LSI technology).
Functions other than clocks have also been put into practical use, such as uttering the time using a human voice and displaying pulse rate and body temperature using a combination of SI and clock LSI.

On the other hand, with regard to radio receivers as well, LSI technology and the miniaturization of electronic components have made it possible to incorporate them into radio receivers, but there are still many problems that remain. That is, the main parts constituting the radio receiver are an antenna 1 as shown in FIG.
, a high frequency tuner 2, a high frequency amplifier 3, a wave detector 4, a low frequency amplifier 5, and a speaker 6. Of these, at the current technological level, three high-frequency amplifiers, four detectors, and five low-frequency amplifiers are used.
can be integrated into an integrated circuit. Also, regarding speaker 6, although the sound quality is currently not satisfactory, it is possible to hear the melody mentioned above.
It has already been put into practical use for pronunciation and voice synthesis, so there is no problem with incorporating it into wristwatches. Also, in some cases, earphones connected to the outside may be used without any practical problems. Rather, it is practical when considering the power battery capacity of the wristwatch.

However, the high frequency tuner 2 uses a tank circuit consisting of an inductance and a capacitor, and the shape of the inductance is large, making it difficult to incorporate it into a wristwatch. on the other hand,
A capacitor fixes the radio station selection, and there is no problem if only one station can be received, but if you want to select multiple stations, you have to use a variable capacitor, which also has the problem of its shape. be. Furthermore, the means of actually operating this is also a problem. Further, as for the antenna 1, it is possible to use a short rod antenna or a human body, but the sensitivity would be very poor.

The present invention solves the problems when these radio receivers are built into wristwatches, and one embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a circuit diagram of a main part of an embodiment of the wristwatch-type radio receiver of the present invention.

In FIG. 2, 7 is an inductor constituting a tuner, which is formed by tightly winding a coil around a magnetic material such as ferrite. This inductance 7 forms a tuning circuit and also serves as an antenna, and is placed outside the wristwatch body. On the other hand, the tuning capacitor is a diode whose capacitance changes depending on the applied voltage.
Use.

The voltage for changing the capacity of this varactor 8 is the voltage of the battery 11.
voltage is divided by a variable resistor 10 and applied to one terminal of the varactor 8. The capacitor 9 is for lowering the impedance of the voltage application line, and the inductor 7 and varactor 8 constitute a variable tuning circuit. This tuning circuit is connected to a high frequency amplifier 13 by a coupling capacitor 12, and is composed of a wave detector, a low frequency amplifier, and a speaker (not shown in the figure below).

FIG. 3 shows a schematic configuration example in which these circuits are implemented in a wristwatch. In the figures, (A) is a plan view thereof, and (B) is a cross-sectional view of the main parts, 14 is the main body of the wristwatch, and 15 is a band. Reference numeral 16 denotes a connecting fitting for coupling the bands on both sides, and 7 denotes a tuning inductor which also serves as an antenna as explained in FIG.

Of course, if the connecting fitting 16 itself is an insulator, the insulator 17
There is no need for Further, since the connecting fitting 16 is usually a bendable part like a band part, but rather is fixed, it is convenient for fixing the inductor 7.

Therefore, assuming the shape of the inductor 7, the antenna effective length Ht indicating its performance is calculated. The inductor 7 is a coil wound around a magnetic material, as shown in FIG.

Here, and t represent the cross-sectional dimensions of the magnetic material, and assuming that the coil winding width and the length of the magnetic material are approximately equal, the effective length of the antenna is expressed as H1 = 2πNAμ/λ... (1) It will be done.

However, A is the cross-sectional area of the magnetic material (tXZ), N is the number of coil turns, μ is the effective permeability of the magnetic material, and λ is the wavelength of the radio wave (λ-2π
f and f are the frequencies of radio waves).

Then, assuming the following as practical values, the effective length is determined from equation (1).

That is, t=5 theory, L-101++++11 N-100
If T1μ = 10, f = 500 kHz, HA
:5.2 x 10'm When HA = 1 m, effective length gain GA = OdB
Therefore, (5) Gt both 20 Log (5,2x 10-') you-66
dB, where the coil Q = 100 and the input electric field i 4
If it is 0 dB, the input Fin to the amplifier = −66
It can be seen that the input level is +40+40-14 dB, which is a realistic input level.

Therefore, it is clear that if the inductor 7 also has the above-mentioned dimensions, it can be attached to the band 15 without any problem.

Next, the two leads a118 from the inductor 7 are connected along the band 15 to one terminal of the varactor 8 (see FIG. 2) in the main body 14 or to a ground wire.

In the embodiment, an example has been described in which the antenna (also serving as an inductor) 7 is attached to the connection fitting 16 of the band 15, but it goes without saying that it may be attached to a part of the band 15.

On the other hand, the main body 14 includes a printed circuit board 21 equipped with a liquid crystal display section 20 for displaying time, a clock circuit LSI, an electric circuit IC for a radio receiver, a tuning varactor 8 (see FIG. 2), etc.
It is constituted by a variable resistor 10Vc that generates a voltage that varies the capacitance of the varactor (6). Note that the variable resistor 10 used is a thin round one. The variable resistor 10 is rotated by rotating a gear attached to a rotating shaft at the center of the variable resistor 10 by a shaft 22 having a worm gear attached to the tip.

A knob for rotation is attached to the other end of the shaft 22, and is exposed outside the main body cover. This is similar to the crown used in traditional mechanical watches to set the time and wind the mainspring. Therefore, this IJ, - acts as a frequency tuning knob of a radio receiver.

As is clear from the above description, if the antenna and tuner are constructed according to the present invention, a wristwatch with a built-in radio receiver can be constructed.

In the above embodiment, a varactor is used as the variable tuning element of the high frequency tuning circuit, but it may also be a micro variable capacitor, a voltage variable inductor, or a small rotary variable inductor. However, in the case of an inductor, if an inductor that is part of the tuning circuit is used in the antenna, a variable inductor is added to it, so naturally the variable range of the tuning frequency becomes narrower, but this is not true for wristwatch-type radios. The purpose of the receiver is achieved. Here, there is a problem that the reception frequency range becomes narrow due to the use of a varactor as a tuning element.

That is, in the case of a digital wristwatch, the power supply voltage for driving the timepiece circuit is 3μ, which makes it difficult to cover the entire receiving frequency range. For example, in the case of the AM band, it is necessary to cover 520 kHz to 1610 kHz, and the capacitance change ratio in this case needs to be about 9 times. This change ratio f: Since it is difficult to cover the applied voltage range of 3 V or less with one varactor, it is covered using two varactors 8a and 8b as shown in FIG.

First, in the low frequency region, two varactors 8
Connect a + 8 b in parallel, cut one off in the middle of the frequency band, and use it alone. In this way, a wide frequency range can be covered even at low voltage. Even if a plurality of rounded varactors are used, they can be integrated into a single chip using semiconductors, so there is no problem of storage space.

As explained in detail above, the present invention has an antenna inductor that forms a high-frequency tuning circuit attached to a watch/watch, and the tuning operation is performed by a knob corresponding to the crown of a conventional wristwatch. This has the effect of allowing a radio receiver to be built in without changing the shape of the device. Therefore, it can be applied to increasing the functionality of wristwatches and miniaturizing radio receivers.

[Brief explanation of drawings]

FIG. 1 is a book diagram of a radio receiver, FIG. 2 is a circuit diagram of essential parts showing an embodiment of the wristwatch-type radio receiver of the present invention, and FIG.
The figures are schematic configuration diagrams showing one embodiment of the wristwatch-type radio receiver of the present invention, in which (A) is a plan view thereof, (B) is a sectional view of the main parts thereof, and FIG. 4 is a perspective view showing an antenna inductor. FIG. 5 is a main circuit diagram showing another embodiment of the receiver of the present invention. l... Antenna, 2... High frequency tuner, 3... High frequency amplifier, 4... Detector, 5... Low frequency amplifier, 6
...Speaker, 7...Antenna inductor, 8+
8 a r8b...Varactor, 13...High frequency amplifier, 14...Wrist (9) Watch body, 15...Band, 16...Connection fittings, 1
7... Insulator, 18... Lead wire, 20... Liquid crystal display section, 21... Print board, 22... Shaft. (10) Figure 4 Figure 5

Claims (1)

[Claims] A wristwatch-shaped radio receiver characterized in that an inductor constituting a high-frequency tuning circuit is attached to a wristwatch hand or a band connection fitting and functions as an antenna.