JPH11332135A - Electronics - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In communication between two or more separated devices,
When both data transfer and power transfer are performed by electromagnetic coupling or electromagnetic induction with coils respectively disposed at positions facing each other, both the efficiencies are achieved. An electronic timepiece (200) is provided in a station (100) that transmits and receives signals by electromagnetic coupling between an electronic timepiece (200) and coils disposed at positions facing each other.
When the power is transferred to the electronic timepiece 200, the outer coil 110b having a small number of turns is used.
b, the switch 111 is used.
a and 111b are switched according to the signal T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device which achieves both efficiency in power transfer and signal transfer by electromagnetic coupling or electromagnetic induction between coils disposed at positions facing each other with respect to a counterpart device. About.

[0002]

2. Description of the Related Art In recent years, small portable electronic devices such as portable terminals and electronic watches have been housed in chargers called stations, and data transfer and the like have been performed together with charging of the portable electronic devices. Here, if charging and data transfer are performed via electrical contacts, these contacts are exposed, which causes a problem in terms of waterproofness. For this reason, it is desirable that charging, signal transfer, and the like be performed in a non-contact manner by electromagnetic coupling of coils provided in both the station and the portable electronic device.

In such a configuration, when a high frequency signal is applied to the coil of the station, an external magnetic field is generated, and an induced voltage is generated in the coil of the portable electronic device. By rectifying the induced voltage with a diode or the like, it becomes possible to contactlessly charge a secondary battery built in the portable electronic device. Also, the electromagnetic coupling between the two coils makes it possible to transfer signals bidirectionally from the station to the portable electronic device or from the portable electronic device to the station in a non-contact manner.

[0004]

By the way, when charging a portable electronic device, it is necessary to set the voltage induced in the coil of the portable electronic device to be higher than the voltage of the secondary battery. It is desirable that the input voltage of the coil on the station side be kept as low as possible. To this end, a configuration is conceivable in which the number of coil turns on the station side is smaller than that of the portable electronic device. On the other hand, when data is transferred to and from a portable electronic device, the secondary battery built into the portable electronic device is greatly restricted in terms of both capacity and size due to weight reduction and size reduction. However, it is desirable that the receiving side be configured to obtain a high voltage. For this purpose, a configuration is conceivable in which the product of the number of coil turns on the station side and the number of coil turns on the portable electronic device is increased. That is, when power is transferred to a portable electronic device,
The required coil characteristics are different between the case of transferring data with the portable electronic device. For this reason, when power transfer and data transfer are performed, there is no choice but to make a design that emphasizes one of the characteristics of the coil, and there is a problem that power transfer and data transfer are not compatible.

[0005] Alternatively, when charging a portable electronic device, a large amount of power is required to perform power transfer, but when transferring data with the portable electronic device, it is necessary to reduce power consumption as much as possible. That is, the request for the power consumed by the coil differs between the case of transferring power to the portable electronic device and the case of transferring data to and from the portable electronic device. For this reason, when power transfer and data transfer are performed, there is no choice but to make a design that emphasizes either one of power consumption, and there is a problem that power transfer and data transfer are not compatible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a portable electronic device, a station, or the like, in which two or more devices separated from each other face each other. An object of the present invention is to provide an electronic device capable of simultaneously improving the efficiency of both data transfer and power transfer even when both data transfer and power transfer are performed by electromagnetic coupling or electromagnetic induction with coils provided respectively. .

[0007]

In order to achieve the above object, according to the first aspect of the present invention, power is transferred to a counterpart device by electromagnetic coupling or electromagnetic induction between coils disposed at positions facing each other. And an electronic device for transferring signals, wherein in the case of power transfer to the counterpart device, a coil having a small number of turns is used, while in the case of signal transfer with the counterpart device, a coil having a large number of turns is used. Features.

[0008] In the second aspect of the present invention, the partner device is an electronic device that transfers power and transfers signals by electromagnetic coupling or electromagnetic induction between coils disposed at positions facing each other. A number-of-turns switching means for switching the effective number of turns of the coil disposed in the case of power transfer to the counterpart device; and controlling switching of the number-of-turns switching means so as to reduce the effective number of turns of the coil. ,
In the case of signal transfer with the counterpart device, the apparatus further comprises a winding number control means for controlling switching of the winding number switching means so as to increase the effective number of turns of the coil.

Further, in the third invention, the first device and the second device perform power transfer and signal transfer by electromagnetic coupling or electromagnetic induction of coils provided at positions facing each other. An electronic device, comprising: a winding number switching unit configured to switch an effective number of windings of at least one of a coil provided in the first device and a coil provided in the second device; In the case of power transfer from the device to the second device, at least,
The switching of the number-of-turns switching means is performed so that the effective number of turns of the coil disposed in the first device is reduced or the effective number of turns of the coil disposed in the second device is increased. In the case of signal transfer between the first and second devices, the effective number of turns of the coil disposed in the first device and the coil disposed in the second device are controlled. And a turn number control means for controlling switching of the turn number switching means so as to increase a product of the turn number and the effective turn number.

According to a fourth aspect of the present invention, when the device is disposed in a predetermined positional relationship with respect to the partner device, the device faces the partner coil provided in the partner device and is electromagnetically coupled to the partner coil. In the case of power transfer to the counterpart device via the coupling coil and the coupling coil, the switch circuit is controlled so that the effective number of turns of the coupling coil is reduced, while the coupling coil is controlled. And a control circuit for controlling the switch circuit so as to increase the effective number of turns of the coupling coil in the case of signal transfer with the counterpart device via the control unit. In addition, according to the fifth aspect of the present invention, when disposed in a predetermined positional relationship with respect to the counterpart device, it faces the counterpart coil provided in the counterpart device and is electromagnetically coupled with the counterpart coil. And a variable impedance circuit interposed in a power supply path of the coupling coil and having a variable impedance. When power is transferred to the partner device, the impedance of the variable impedance circuit is reduced. When a signal is transferred to or from a device, an impedance switching circuit for increasing the impedance of the variable impedance circuit is provided.

[0011]

Embodiments of the present invention will be described below. In the present embodiment, a station will be described as an example of an electronic device, and an electronic timepiece will be described as an example of a counterpart device. However, the present invention is not limited to these.

<1. First Embodiment><MechanicalConfiguration> FIG. 1 is a plan view showing the configuration of a station and an electronic timepiece according to an embodiment. As shown in this figure, the electronic timepiece 200 is housed in the recess 101 of the station 100 when performing charging, data transfer, or the like. Since the recess 101 is formed in a slightly larger shape than the main body 201 and the band 202 of the electronic timepiece 200, the timepiece main body 201 is accommodated in a state positioned with respect to the station 100. The station 100 includes an input unit 103 for inputting an operation to start charging and a display unit 10 for performing various displays.
4 are provided. It is needless to say that the electronic timepiece 200 according to the present embodiment is worn on the user's arm in a normal use state, and the date and time and the like are displayed on the display unit 204. It is configured to detect and store biological information such as heart rate and heart rate at regular intervals.

FIG. 2 is a sectional view taken along line AA in FIG. As shown in the figure, a watch side coil 210 for data transfer and charging is provided on a lower back cover 212 of a main body 201 of an electronic timepiece via a cover glass 211. Further, the watch main body 201 is provided with a circuit board 221 connected to the secondary battery 220, the watch side coil 210, and the like.

On the other hand, an inner coil 110a and an outer coil 110b are provided via a cover glass 111 at a position facing the clock coil 210 in the recess 101 of the station 100. Here, as shown in FIG. 3, the inner circumferential coil 110a and the outer circumferential coil 110b have the same winding direction, and are arranged substantially concentrically and substantially on the same plane. Here, for convenience of explanation,
The terminals of the inner coil 110a are A and B as shown in the figure,
Similarly, the terminals of the outer peripheral coil 110b are C and D. FIG. 3 shows the inner coil 110a and the outer coil 110b.
This is merely a diagram for explaining the arrangement, and the actual number of turns (the number of turns), the thickness of the copper wire, and the like do not match the actual scale. Specifically, the inner circumferential coil 1 according to the present embodiment
10a is a copper wire having a diameter of 0.1 [mm] with 50 turns, and the outer peripheral coil 110b is a copper wire having a diameter of 0.18 [mm] with 25 turns.
It is a turn. That is, in the present embodiment, the number of turns of the outer circumferential coil 110b is
The number of turns is smaller than 0a. The station 100 includes an inner coil 110.
a, outer peripheral coil 110b, input unit 103, display unit 10
4. Circuit board 1 to which a primary power supply (not shown) is connected
21 are provided.

As described above, when the electronic timepiece 200 is housed in the station 100, the inner coil 110a or the outer coil 110b on the station side and the clock coil 210 are physically separated by the cover glasses 111 and 211. Although it is non-contact, since the coil winding surface is parallel, it is electromagnetically coupled. The inner coil 110a, the outer coil 110b, and the clock coil 210 on the station side are the reasons for avoiding the magnetization of the clock mechanism, the reason for avoiding the weight increase on the clock side, and the reason for avoiding the exposure of the magnetic metal. As a result, it is an air-core type without a magnetic core. Therefore, when applied to an electronic device in which such a problem does not occur, a coil having a magnetic core may be employed. However, if the frequency of the signal applied to the coil is sufficiently high, the air-core type is sufficient.

Now, the inventors of the present application have described the station 10
0, the power transfer characteristics and the signal transfer characteristics when various coils were used were determined experimentally. Therefore, the results of this experiment will be described. In this experiment, for convenience, the inner peripheral coil 110a and the outer peripheral coil 110b on the station 100 side are the primary side, and the clock side coil 21
0 is the secondary side. The coils used in the station 100 are of three types: an inner coil 110a only, an outer coil 110b only, and a series coil composed of an inner coil 110a and an outer coil 110b connecting terminals B and C. is there.

First, FIG. 9 shows actual measurement results showing characteristics of a voltage (battery voltage) on the secondary side and a charging current on the secondary side when power is transferred from the primary side to the secondary side. As shown in this figure, when the battery voltage is the same, the charging current obtained by rectifying and smoothing the signal induced on the secondary side becomes the largest when the outer peripheral coil 110b is used. In other words, when power is transferred from the station 100 to the electronic timepiece 200, if the outer peripheral coil 110b is used on the station 100 side, a large charge can be obtained even if the voltage induced on the secondary side increases and the battery voltage increases. It can be seen that since the secondary battery can be charged with the current, it is advantageous in terms of charging efficiency.

Next, FIG. 10 shows actual measurement results showing characteristics of current consumption on the secondary side and induced voltage on the primary side when a signal is transferred from the secondary side to the primary side. As shown in this figure, if the secondary side current is the same, the voltage induced on the primary side is only the series coil, the inner peripheral coil 110a,
It becomes higher in the order of the outer peripheral coil 110b. That is,
When a signal is transferred from the electronic timepiece 200 to the station 100, if a series coil is used on the station 100 side, the product of the number of turns of the primary side coil and the number of turns of the secondary side coil becomes large. Even if the power consumption is low, the voltage induced on the self side can be efficiently increased. For similar reasons, the station 10
Even when a signal is transferred from 0 to the electronic timepiece 200, if a series coil is used on the station 100 side, the product of the turns of both coils increases, so that even if the power consumption of the station 100 is low, the signal is induced on the electronic timepiece 200 side. Voltage can be increased efficiently.

Therefore, in the present embodiment, as described in the following electrical configuration, when power is transferred, the number of turns of the primary side coil as viewed from the secondary side is reduced, so that the outer peripheral coil 110b having a small number of turns is used. On the other hand, in the case of signal transfer, a series coil is used to increase the product of the number of turns of the primary coil and the number of turns of the secondary coil.

<Electrical Configuration> The station 10
0 and the electrical configuration of the electronic timepiece 200 will be described with reference to FIG. First, the station 100 will be described. In this figure, an oscillation circuit 140 outputs a clock signal CLK for synchronizing the operation of each unit. The input unit 103 supplies a one-shot pulse STR to the counter 150 when a charging operation is performed by the user. The counter 150
This circuit controls the connection of the coil on the station 100 side. When a pulse STR is supplied, the preset value n is down-counted by the clock signal CLK, and a signal T which becomes H level is output during the count operation. .
That is, the output signal T of the counter 150 is configured to be at the H level for a certain period from the operation of starting charging to the elapse of n cycles of the clock signal CLK. The signal T is supplied to the control terminal of the switch 111a after being inverted in level by the inverter 151.
The control terminal of the switch 111b is supplied directly. Here, each of the switches 111a and 111b is turned on when a signal supplied to its control terminal becomes H level. Therefore, the switches 111a, 111b
Are configured to be selectively turned on in accordance with the level of the signal T. The signal T is also supplied to one input terminal of the AND gate 152.

On the other hand, the inner coil 110a and the outer coil 110b are connected in series by connecting the terminals B and C. However, one terminal A of the inner peripheral coil 110a
And one terminal C of the outer coil 110b (the inner coil 1
The other terminals B) of 10a are switches 111a and 111b that selectively switch according to the signal T, respectively.
Is connected to the power supply voltage Vcc via the
In the case of the signal level, only the outer coil 110b is pulled up to the power supply voltage Vcc, while when the signal T is at the L level, the inner coil 110a and the outer coil 110b are pulled up.
Is pulled up to the power supply voltage Vcc.

Next, the terminal D of the outer peripheral coil 110b is connected to the drain of the transistor 153. Here, the gate of the transistor 153 is connected to the output of the AND gate 153 receiving the supply of the clock signal CLK at the other input terminal, while the source of the transistor 153 is grounded. Therefore, when the output signal T of the counter 150 becomes H level, the clock signal CLK becomes the output signal S1 of the AND gate 152 as it is, and switches between the drain and source of the transistor 153 according to the level. ing.

On the other hand, the signal S2 at the terminal D of the outer peripheral coil 110b is supplied to the receiving circuit 154. The receiving circuit 154 demodulates the signal S2 using the clock signal CLK, and outputs the demodulation result as a signal S3. The configuration of the receiving circuit 154 will be described later. The processing circuit 155 is a circuit that executes a process based on the demodulated signal S3. In the present embodiment, for example,
The processing result is displayed on the display unit 104.

Next, the electronic timepiece 200 will be described. One terminal of the clock side coil 210 is a diode 2
The other terminal of the coil 210 is connected to the negative terminal of the secondary battery 220 while being connected to the positive terminal of the secondary battery 220 via 45. Here, the configuration is such that the voltage Vcc of the secondary battery 220 is used as a power source for each unit in the electronic timepiece 200. Also, the control circuit 230
Supplies a digital data W2 to be transmitted to the station 100 to the transmission circuit 250 when the signal W1 is not induced, while providing a time display function to the display unit 204 with a timekeeping function. is there. here,
As the data to be transmitted to the station 100, biological information such as a pulse rate and a heart rate measured by a sensor (not shown) or the like is assumed.

The transmission circuit 250 serializes data to be transmitted to the station 100 and outputs a switching signal obtained by bursting a signal of a constant frequency during a period when the serial data is at the L level. The switching signal from the transmission circuit 250 is
The signal is supplied to the base of the transistor 252 via 51. The collector of the transistor is a secondary battery 22
The emitter of the transistor is connected to one terminal of the coil 210 while being connected to the positive terminal of 0.
Therefore, in the clock side coil 210, the signal W2
Is induced, the signal is half-wave rectified and the secondary battery is charged. On the other hand, when the signal W2 is not induced, a switching signal corresponding to data to be transmitted to the station 100 is generated. It is configured to be supplied.

Here, the receiving circuit 1 of the station 100
The configuration of 54 will be described with reference to FIG. The configuration shown in the drawing is merely an example, and is originally determined by the modulation method in the transmission circuit 250 of the electronic timepiece 200. First, as shown in FIG. 6, a signal S2 induced at a terminal D of a series coil composed of an inner coil 110a and an outer coil 110b is inverted in level and waveform-shaped by an inverter circuit 1541 as shown in FIG. 4) clock signal C
D flip-flops 1542, 1543 synchronized with LK
Is supplied as a reset signal RST. Here, the input terminal D of the D flip-flop 1542 is connected to the power supply voltage Vcc.
, While its output terminal Q is connected to the input terminal D of the next-stage D flip-flop 1543. And D
The output terminal Q of the flip-flop 1543 is output as a signal S3 as a demodulation result.

Next, the waveform of each part in the receiving circuit 154 having the above configuration will be examined. At the time of receiving data from the electronic timepiece 200, the series coil composed of the inner coil 110a and the outer coil 110b is pulled up to the power supply voltage Vcc, as described later. If a magnetic field is not generated, the pull-up level is attained. On the other hand, if an external magnetic field is generated, the level fluctuates at a level induced accordingly. Therefore, the signal S2 induced at the terminal D is
For example, as shown in FIG. In response to such a signal S2, the signal RST output from the inverter circuit 1541 is, as shown in FIG.
Becomes H level when the voltage falls below the threshold value Vth, and the D flip-flops 1542 and 1543 are reset. At this time, D flip-flops 1542, 1543
Outputs the level of the input terminal D immediately before the rising edge of the clock signal CLK, so that the output Q1 of the D flip-flop 1542 and the output S3 of the D flip-flop 1542 are respectively shown in FIGS. e)
It becomes as shown in. That is, the output signal S3 of the receiving circuit 154 is a signal that becomes L level during the period when the external magnetic field is generated by the clock side coil 210. Here, the period during which the external magnetic field is generated by the clock side coil 210 is a period during which the data to be transmitted from the electronic timepiece 200 to the station 100 is at the L level. It can be seen that the signal is demodulated.

<Operation> Next, a charging operation and a data transfer operation in the station 100 and the electronic timepiece according to the present embodiment will be described. First, the user causes the electronic timepiece 200 to be housed in the recess 101 of the station 100. Thereby, the inner circumferential coil 11 on the station side is
0a, the outer peripheral coil 110b, and the watch side coil 210 face each other as shown in FIG. Thereafter, when the user performs an input operation to start charging by operating the input unit 103 of the station 100, as shown in FIG. 5A, a pulse STR of one shot is input at a timing t1. Output from the unit 103. Therefore, since the counter 150 starts the counting operation, the signal T goes high as shown in FIG. 5B.

When the signal T goes high, the switch 11
As shown by solid lines in FIG. 4, 1a and 111b are turned off and on, respectively, so that only the outer peripheral coil 110b is pulled up to the power supply voltage Vcc, while the AND gate 152 is opened, so that the transistor 153 sets the clock signal CLK. Switching according to. Therefore, since the transistor 153 switches with a waveform as shown in FIG. 5C, a pulse signal obtained by switching the power supply voltage Vcc with the clock signal CLK is applied to the outer peripheral coil 110b, and an external magnetic field is generated. It will be.
The signal W1 having the same cycle as the pulse signal is induced in the clock side coil 210 by the external magnetic field. This induced signal is half-wave rectified by the diode 245 to charge the secondary battery 220.

Next, when the counter 150 counts down the preset value n with the clock signal CLK and becomes zero at the timing t2 shown in FIG. 5B, the signal T goes low. When the signal T goes to the L level, the switches 111a and 111b are turned on and off, respectively, as indicated by broken lines in FIG.
While the series coil including the inner coil 110a and the outer coil 110b is pulled up to the power supply voltage Vcc,
Since the AND gate 152 is closed, the transistor 153
Turns off regardless of the clock signal CLK. Therefore, no signal is induced in the clock-side coil 210.

As a result, while the charging of the secondary battery 220 is completed, the control circuit 230 supplies digital data W2 to be transmitted to the station 100 to the transmission circuit 250. Will be started. Here, station 1
Assuming that the data to be transmitted to 00 is as shown in FIG. 5D, the switching signal of the transmitting circuit 250 is set such that the output is H level if the data is H level, and if the data is L level. For example, since it is assumed that a pulse signal of a constant frequency is burst, the transistor 252
Switches with a waveform as shown in FIG.

Therefore, a pulse signal is applied to the clock-side coil 210 during a period when data to be transmitted to the station 100 is at the L level.
As a result, an external magnetic field is generated. By the external magnetic field, on the station 100 side, a signal S2 having the same cycle as the pulse signal is induced at a terminal D of a series coil including the inner coil 110a and the outer coil 110b. Here, during the period when the signal is induced, the signal S3 is set to L by the receiving circuit 154 having the above configuration.
After all, on the station 100 side,
After the timing t2, a signal S3 obtained by demodulating the digital data W2 from the electronic timepiece 200 is obtained. Then, on the station 100 side, the processing circuit 155 executes processing based on the demodulated signal S3, and the processing result is displayed on the display unit 104.

As described above, the station 100 according to the present embodiment uses the outer coil 110b having a small number of turns when charging, that is, transferring power, while using the inner coil 110a and the outer coil 110b when transferring data. Are used in series. With such a configuration, at the time of power transfer, the number of turns of the station-side coil viewed from the clock side is relatively small, while at the time of signal transfer, the product of the number of turns of the station-side coil and the number of turns of the clock-side coil is large. Therefore, it is possible to improve both the efficiency of power transfer via the coil and the efficiency of signal transfer. Further, in the present embodiment, after the secondary battery 220 of the electronic timepiece 200 is charged from the timing t1 to t2 by generating an external magnetic field, data transfer is performed after the timing t2. Secondary battery 2
It is possible to prevent a situation in which data cannot be transferred due to a voltage drop of 20.

<2. Second Embodiment><2-1. Outline of Second Embodiment> Next, a second embodiment of the present invention will be described. In the first embodiment, the number of windings of the coil can be switched between when power is transferred to the electronic timepiece 200 and when the signal is transferred to and from the electronic timepiece 200. The configuration is such that the impedance on the side is variable. Hereinafter, a specific configuration will be described, but since the external configuration is the same as that of the first embodiment (see FIG. 1), illustration and detailed description are omitted.

<2-2. Electrical Configuration> FIG. 11 is a diagram showing an electrical configuration of the station 100. Since the configuration of the electronic timepiece 200 is the same as that of the first embodiment, its illustration and description are omitted, and
Only the side will be described. In the present embodiment, the coil 110 is a coil provided at a position facing the clock-side coil 210 in the concave portion 101 (see FIG. 2) of the station 100. Reference numeral 112 denotes a variable impedance circuit that includes external resistors 112a and 112b having different resistance values to make the impedance variable, and is inserted in the power supply path of the coil 110. More specifically, one end C of the coil 110 is connected to the switch 111
b, 111a are connected to one end of the switch 111b, 1
The other end of 11a is connected to a power supply terminal (voltage Vcc) via a resistor 112b and a resistor 112a, respectively. First
As in the embodiment, the switches 111a and 111b are configured to be selectively turned on according to the level of the signal T, and the coil 110 is externally connected when the signal T is at the H level (during charging). While the signal T is pulled up to the power supply voltage Vcc via the resistor 112b, when the signal T is at the L level (during data transfer), the power supply voltage Vc is supplied via the external resistor 112a.
c.

The other end D of the coil 110 is connected to the drain of the transistor 153 and the input terminal of the receiving circuit 154. The output signal S1 of the AND gate 152 that calculates the logical product of the signal T and the clock signal CLK is supplied to the gate of the transistor 153. Other input unit 1
03, display unit 104, oscillation circuit 140, counter 15
0, an inverter 151, an AND gate 152, a transistor 153, a receiving circuit 154, and a processing circuit 155.
Are the same as in the first embodiment (FIG. 4).

According to the above-described configuration, when the output signal T of the counter 150 goes to the H level (during charging), the clock signal CLK becomes the output signal S1 of the AND gate 152 as it is, and according to the level. Transistor 15
3 is switched between the drain and the source. As a result, the power supply voltage Vc
Since a pulse signal obtained by switching c with the clock signal CLK is applied, an external magnetic field is generated.

In this embodiment, the resistance Ra of the external resistor 112a is larger than the resistance Rb of the external resistor 112b. Thus, when power is transferred to the electronic timepiece 200, the impedance of the variable impedance circuit 112 is reduced, and when signal transfer is performed with the electronic timepiece 200, the impedance of the variable impedance circuit 112 is increased. Therefore, when a signal is transferred between the electronic timepiece 200 and the electronic timepiece 200, the voltage and current input to the coil 110 are reduced, so that the power required for communication with the electronic timepiece 200 can be reduced. On the other hand, when power is transferred to the electronic timepiece 200, the voltage and current input to the coil 110 increase,
High power can be transferred to 0.

Here, the waveform of each part of the receiving circuit 154 in this embodiment will be examined with reference to FIG. FIG. 12 is a waveform comparing the case where the impedance of the variable impedance circuit 112 is large ((1) in FIG. 12) and the case where it is small ((2) in FIG. 12). First, the case in FIG. 12A will be described. When the transistor 153 is turned off and the coil 110 is pulled up to the power supply voltage Vcc, the terminal D has the pull-up level unless an external magnetic field is generated by the clock side coil 210. On the other hand, if an external magnetic field is generated, it fluctuates at a level induced accordingly. Therefore, as described with reference to FIG. 7 in the first embodiment, the signal S2 induced at the terminal D is, for example, as shown in FIG.
The result is as shown in FIG. In response to such a signal S2, a signal RST output from the inverter circuit 1541 is output.
Becomes H level when the voltage of the signal S2 falls below the threshold value Vth, as shown in FIG. 12B, and resets the D flip-flops 1542 and 1543. At this time, the D flip-flops 1542 and 1543 output the level of the input terminal D immediately before the rising edge of the clock signal CLK.
542 and the D flip-flop 154
2 are as shown in FIGS. 12D and 12E, respectively. That is, the output signal S3 of the receiving circuit 154 is a signal that becomes L level during the period when the external magnetic field is generated by the clock side coil 210. Here, the period during which the external magnetic field is generated by the clock side coil 210 is
Since the period during which the data to be transmitted from the electronic timepiece 200 to the station 100 is at the L level, the signal S3
Indicates that the data from the electronic timepiece 200 is accurately demodulated.

When the external magnetic field is generated, the level V of the signal S2 induced at the terminal D depends on the current I induced by the external magnetic field and the combined resistance component Z of the coil 110 and the variable impedance circuit 112. (V = Z × I). In the case where the impedance of the variable impedance circuit 112 is small (2), if the fluctuation width of the current I is the same, the fluctuation width of the level V of the signal S2 becomes small, and as a result, the voltage V may not fall below the threshold Vth. . In the example shown in FIG. 12, the level V of the signal S2 is lower than the threshold value Vth at the time t1 of (1), but is not lower than the threshold value Vth at the time t1 of (2). . Therefore, the variable impedance circuit 11
In the case where the impedance of (2) is small (2), at time t1
, The output signal RST of the inverter circuit 1541
Remains at the L level, and the D flip-flop 1542
7 and the output S3 of the D flip-flop 1542 remain at the H level as shown in FIGS. 7D and 7E, respectively, and accurately demodulate the data from the electronic timepiece 200. Can not do it. That is,
When the impedance of the variable impedance circuit 112 is large (1), more stable data transfer can be performed than when the impedance is small (2).

As described above, in the second embodiment, when the variable impedance 112 is inserted into the power supply path of the circuit coil 110 and the power is transferred to the electronic timepiece 200, the impedance of the variable impedance circuit 112 is reduced. When performing signal transfer with the 200,
Since the impedance of the variable impedance circuit 112 is increased, it is possible to improve both the efficiency of power transfer through the coil and the efficiency of signal transfer.

<3. Modifications> In the above embodiment, the following modifications are possible. That is, in the first embodiment, when data is transferred, a configuration using a series coil including two coils is used. However, a configuration using only a coil having a large number of turns may be used. further,
In the first embodiment, the number of turns of the outer coil 110b is smaller than the number of turns of the inner coil 110a. Conversely, the number of turns of the inner coil 110a is changed to the number of turns of the outer coil 110b. When the power is transferred to the electronic timepiece 200 with a smaller number of turns, the inner peripheral coil is used, and when the data is transferred to the electronic timepiece 200, the outer peripheral coil or a series coil composed of both is used. It is good.

In addition, as shown in FIG. 8, a configuration may be used in which two independent coils having different numbers of turns are used for power transfer to the electronic timepiece 200 and data transfer to the electronic timepiece 200 as shown in FIG. . That is, when power is transferred to the electronic timepiece 200, the coil 110c having a small number of turns may be used, and when data is transferred to the electronic timepiece 200, the coil 110d having a large number of turns may be used. When two independent coils are used separately, a switch having a small number of turns for power transfer and a coil having a large number of turns for data transfer are fixedly used without using a switch. Is also good.

In the first embodiment, the configuration is such that the coil selection is pulled up by the switches 111a and 111b, but a configuration in which the coil terminals are short-circuited may be used. For example, in FIG.
When the power is directly pulled up to the power supply voltage Vcc without passing through the terminal 11a and the power is transferred to the electronic timepiece 200, the terminals A and B are short-circuited to invalidate the inner peripheral coil 110a, while the electronic timepiece 200 When the signal is transferred, a configuration may be adopted in which the terminals A and B are opened and a series coil including the inner coil 110a and the outer coil 110b is made effective. That is, the effective number of turns of the coil referred to in the present application means not only the physical number of turns of the coil but also the number of electric turns of the coil. In the second embodiment,
The means for changing the impedance of the station 100 has been described as switching the external resistors 112a and 112b. However, the present invention is not limited to this, and an external coil may be switched, or as shown in the first embodiment. The number of turns of the coil is changed to the station 100.
The impedance on the side may be changed.

In the above-described embodiment, the data transfer is performed only in one direction from the electronic timepiece 200 to the station 100. However, the data transfer may be performed in the direction from the station 100 to the electronic timepiece 200. Electronic clock 20
When the data is transferred to the station 100, the station 100 modulates the data according to the data to be transferred.
Then, the demodulation may be performed according to the modulation method. At this time, a known technique may be applied to modulation and demodulation. Even in such a configuration, even if the current consumption on the station 100 side is small, a high voltage is induced on the electronic timepiece 200 side, so that the transfer efficiency is improved.

In addition, in the embodiment, the station 100 is used as an electronic device, and the electronic timepiece 200 is used as a counterpart device.
However, in the present application, these distinctions are meaningless, including the distinction between the first and second devices, and are applicable to all electronic devices that perform power transfer and signal transfer. For example, electric toothbrush, electric shaving, cordless telephone, mobile phone, personal handy phone, mobile personal computer, PDA (Personal Digital Assistants:
The present invention can be applied to an electronic timepiece including a secondary battery such as a personal information terminal) and its charger. By the way, in the embodiment, the coil on the station 100 side is switched between power transfer and signal transfer, or
The reason why the impedance on the 0 side is variable and the coil or the impedance on the electronic timepiece 200 side is fixed is that, in an electronic device such as the electronic timepiece 200 which is required to be small and light, the configuration for switching the coil is a matter of mounting. It is almost impossible or very difficult. Therefore, when the present invention is applied to an electronic device whose mounting restrictions are loose, the coil may be switched on the electronic device side instead of the charger side.

[0047]

As described above, according to the present invention, data transfer and power transfer between two or more devices separated from each other by electromagnetic coupling or electromagnetic induction with coils respectively disposed at positions facing each other. Even when both are executed, it is possible to achieve both efficiencies.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a station and an electronic timepiece according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of the station and the electronic watch.

FIG. 3 is a plan view showing an arrangement of coils in the station.

FIG. 4 is a block diagram showing an electrical configuration of the station and the electronic watch.

FIG. 5 is a timing chart for explaining operations of the station and the electronic timepiece.

FIG. 6 is a circuit diagram showing an example of a receiving circuit of the station.

FIG. 7 is a timing chart for explaining the operation of the receiving circuit.

FIG. 8 is a block diagram showing a configuration around a coil of a station according to a modification of the present invention.

FIG. 9 is a diagram for explaining an advantage of the present embodiment, and is a diagram showing a battery voltage-secondary current (charging current) characteristic.

FIG. 10 is a diagram for explaining an advantage of the present embodiment, and is a diagram showing a secondary current-primary voltage characteristic.

FIG. 11 is a block diagram illustrating an electrical configuration of a station according to the second embodiment.

FIG. 12 is a timing chart for explaining the operation of the receiving circuit in the second embodiment.

[Explanation of symbols]

100 station (electronic device, first device), 1
10a ... inner circumference coil, 110b ... outer circumference coil, 11
1a, 111b ... switch (turn number switching means, switch circuit), 150 ... counter (turn number control means, control circuit), 200 ... electronic timepiece (counterpart device, second device), 210 ... coil, 220 ... ... Secondary battery (charging means), 245 ... Diode (rectifying means)

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyuki Honda 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation

Claims (17)

[Claims] A partner device is an electronic device that transfers power and transfers signals by electromagnetic coupling or electromagnetic induction between coils disposed at positions facing each other, and in the case of transferring power to the partner device. Is characterized in that a coil having a small number of turns is used, while a coil having a large number of turns is used in the case of signal transfer with the counterpart device. 2. The electronic device according to claim 1, wherein the coil having a small number of turns or the coil having a large number of turns is a substantially concentric inner or outer circumferential coil. 3. The electronic device according to claim 1, wherein the coil having a small number of turns or the coil having a large number of turns is an air-core type. 4. A counterpart device is an electronic device which transfers power and transfers signals by electromagnetic coupling or electromagnetic induction between coils disposed at positions facing each other, wherein the coils disposed in the other device are effective. In the case of power transfer to the counterpart device, the number of turns is switched so as to reduce the effective number of turns of the coil. In this case, the electronic device further includes a winding number control unit that controls switching of the winding number switching unit so that the effective number of windings of the coil increases. 5. An electronic device in which a first device and a second device perform power transfer and signal transfer by electromagnetic coupling or electromagnetic induction of coils respectively disposed at positions facing each other, wherein Winding number switching means for switching the effective number of windings of at least one of the coils provided in the device or the coils provided in the second device; and from the first device to the second device. In the case of the power transfer, at least the effective number of turns of the coil arranged in the first device is reduced, or
While controlling the switching of the number-of-turns switching means so as to increase the effective number of turns of the coil disposed in the device, the signal transfer between the first and second devices is performed in the first device. Winding number control means for controlling switching of the winding number switching means so that the product of the effective number of windings of the coil arranged in the device and the effective number of windings of the coil arranged in the second device increases. An electronic device comprising: 6. The second device further comprises: a rectifier for rectifying a signal induced in a coil disposed therein, and a charger for charging the signal rectified by the rectifier. The electronic device according to claim 5, wherein: 7. The electronic device according to claim 5, wherein the second device is portable. 8. The electronic device according to claim 4, wherein the coil is of an air-core type. 9. The method according to claim 4, wherein the number-of-turns control means performs switching for a certain period of time in the case of power transfer, and then controls for switching in the case of signal transfer.
Or the electronic device according to 5. 10. The electronic device according to claim 4, wherein the coil comprises a substantially concentric inner peripheral coil and an outer peripheral coil. 11. The winding number of the outer circumference coil is smaller than that of the inner circumference coil, and in the case of power transfer, the winding number switching means uses only the outer circumference coil. 11. The electronic apparatus according to claim 10, wherein switching of the means is controlled. 12. The outer coil has a smaller number of turns than that of the inner coil, and the turns control means includes a series of the inner coil and the outer coil in the case of signal transfer. 11. The electronic apparatus according to claim 10, wherein switching of the winding number switching means is controlled so as to use a coil. 13. The inner circumference coil has a smaller number of turns than the outer circumference coil, and in the case of power transfer, the turn number control means controls the number of turns to use only the inner circumference coil. 11. The electronic apparatus according to claim 10, wherein switching of the switching unit is controlled. 14. The inner peripheral coil has a smaller number of turns than the outer peripheral coil, and the turns control means includes a series of the inner peripheral coil and the outer peripheral coil in the case of signal transfer. 11. The electronic apparatus according to claim 10, wherein switching of the winding number switching means is controlled so as to use a coil. 15. A coupling coil which, when placed in a predetermined positional relationship with respect to a counterpart device, faces a counterpart coil provided in the counterpart device and electromagnetically couples with the counterpart coil; A switch circuit for switching the effective number of turns of the coupling coil, and in the case of power transfer to the counterpart device, while controlling the switch circuit so that the effective number of turns of the coupling coil is reduced, A control circuit for controlling the switch circuit so that the effective number of turns of the coupling coil is increased in the case of the signal transfer of (1). 16. A coupling coil which, when placed in a predetermined positional relationship with respect to a partner device, faces a partner coil provided in the partner device and electromagnetically couples with the partner coil, A variable impedance circuit interposed in the power supply path of the coupling coil and having a variable impedance; and when performing power transfer to the partner device, reduce the impedance of the variable impedance circuit to transfer a signal between the variable device and the partner device. Electronic equipment, comprising: an impedance switching circuit for increasing the impedance of the variable impedance circuit. 17. The variable impedance circuit has a plurality of resistors, and the impedance switching circuit reduces the value of a resistor inserted in the power supply path in the case of power transfer, and reduces the value of the power supply in the case of signal transfer. 17. The electronic device according to claim 16, wherein a value of a resistor inserted in the path is increased.