JPH09134239A - Power controller for non-contact data communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power, to inhibit the consumption of a battery and to prolong the life of a responder. SOLUTION: A power-on signal is transmitted from a reader/writer 31 to a data storage body 32 when data communication starts. The power-on signal received by a transmission part 53 is inputted to a switch circuit 58 through a power-on circuit 56 and the circuit 58 is turned on. Direct current from a power supply 57 is a control circuit, a memory 52, a demodulation circuit 54 and a modulation circuit 55, which are a power on/off object circuit Cr and which are not conducted. Then, all the circuits become operation states. Then, data communication is executed and the power-off signal at the time of data communication stop is received by the transmission part 53. The switch circuit 58 is turned off through the demodulation circuit 54 and the control circuit 51 and the supply of direct current from the power supply 57 is stopped to the power on/off object circuit Cr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transponder such as a reader / writer that reads data from or writes data to a transponder such as a non-contact data storage body. The present invention relates to a power supply control device for a non-contact data communication device that controls ON / OFF of power supply from a power supply to a circuit (power supply ON / OFF control).

[0002]

2. Description of the Related Art FIG. 8 shows a configuration of a power supply control device for a non-contact data communication device for performing power on / off control when a reader / writer of a conventional example performs data communication with a non-contact data storage body. It is a block diagram shown. In FIG. 8, this conventional example is roughly configured by a reader / writer 1 for reading or writing data in a non-contact manner and a data storage body 2 in which the data is read out and written by the reader / writer 1 in a non-contact manner. Has been done.

The reader / writer 1 controls each part when receiving a command for reading data from a higher-order device (not shown) and controls reading or writing of data to the data storage body 2, and this control part. And a command generation circuit 12 that generates and outputs a command under the control of 11. Furthermore, the command generation circuit 1
A modulation circuit 13 that outputs a modulation signal modulated by a command from 2, and the modulation signal from the modulation circuit 13 are transmitted to the data storage body 2 by electromagnetic induction coupling using a coil, for example. The transmission unit 14 that receives the transmission signal (modulation signal) from the data storage body 2 and the modulation signal that is received from the data storage body 2 through the transmission unit 14 are demodulated,
The demodulation circuit 15 that outputs the demodulated data to the control unit 11 is provided.

The data storage unit 2 includes a control circuit 21 for controlling each section here and a non-volatile serial EEPROM.
And a memory 22 for storing data to be transmitted,
A modulation circuit 23 is provided which outputs a modulation signal modulated by the data read by the control circuit 21 in response to a read request from the reader / writer 1 from the memory 22. Also,
The modulation signal from the modulation circuit 23 is transmitted to the reader / writer 1 by electromagnetic induction coupling using a coil or the like,
Further, the transmission section 24 for receiving the modulation signal from the reader / writer 1 and the demodulation circuit 25 for outputting the demodulation data obtained by demodulating the modulation signal from the reader / writer 1 received by the transmission section 24 to the control circuit 21 are provided. There is. Further, a signal detection circuit 26 that detects a transmission signal from the reader / writer 1 and outputs the signal to the control circuit 21 and all the circuits from the control circuit 21 to the signal detection circuit 26 are supplied with direct current, and a power source using a battery is used. And 27.

Next, the operation of the conventional example will be described. 8, in the data read operation of the data storage body 2 by the reader / writer 1, it is determined that the data storage body 2 is within the communicable range of the reader / writer 1, for example, by an upper device (not shown) The control unit 11 receives a data read command for the data storage body 2. The control unit 11 uses the command generation circuit 1
2 is controlled, the command generated here is sent to the modulation circuit 13, and the modulation is performed. This modulated signal is transmitted from the transmission unit 14 to the transmission unit 24 in the data storage body 2 by electromagnetic induction coupling or the like.

The command transmitted at this time is data such as a read command and an address. The modulated signal received by the transmission unit 24 of the data storage body 2 is the demodulation circuit 2
Demodulated at 5. The control circuit 21 takes in the demodulation command, and controls reading or writing of data to the memory 22 according to this command. The data read from the memory 22 is modulated by the modulation circuit 23 according to the bit “0, 1” and sent to the reader / writer 1 through the transmission unit 24. This transmission signal is received by the transmission unit 14 of the reader / writer 1, and the reception signal is demodulated by the demodulation circuit 15.
Is input to and demodulating. This demodulated data is output to the control unit 11.

Such a data storage body 2 is constantly operating, and a DC voltage is applied from the power supply 27 to all circuits of the signal detection circuit 26 from the control circuit 21. In order to reduce the power consumption at this time, the transmission signal from the reader / writer 1 is detected through the transmission section 24, the demodulation circuit 25, and the signal detection circuit 26, and is output to the control circuit 21 for resetting. Further, when the transmission signal from the reader / writer 1 is received by the data storage body 2 and demodulated, the signal detection circuit 26 counts the number of received signals, recognizes the transmission from the reader / writer 1, and controls the signal. The reset of the circuit 21 is released. Then, the control circuit 21 notifies the signal detection circuit 26 of the end of the data communication after executing the data communication according to the communication control (sequence), and the control circuit 21 is reset again to the initial state by the end notification. Is set.

As described above, even in the conventional power supply control device for the non-contact data communication device, the control circuit 2 which consumes a relatively large amount of current.
1 is reset to save power.

[0009]

However, in such a conventional power supply control device for a non-contact data communication device, the control circuit 21 which consumes a relatively large amount of current is reset when data communication is not being performed. Although it is possible to reduce the current consumption, effective power saving cannot be performed because the direct current is supplied to other circuits. Therefore, the power source 2
7 has a drawback that the battery is quickly consumed and the life of the data storage body 2 is shortened as a result.

The present invention solves the drawbacks of the prior art as described above, and turns on / off the direct current supply from the power source to the internal circuit of the transponder from the transmitter / receiver at the start and end of the data communication. Not only can control (power on / off control) be performed, but the power of the transponder can be turned off after a certain period of time, ensuring reliable power saving, preventing battery drain, and extending the life of the transponder. A power supply control device for a contact data communication device is provided.

[0011]

In order to achieve this object, according to the present invention, a transceiver reads data from or writes data to a transponder, and the transceiver turns on / off the transponder. A power supply control device for a non-contact data communication device that performs an off control, including a transmitter for transmitting and receiving a signal for performing a power on / off control for a responder to a transceiver, and a transmission of the responder. The unit receives the power on / off control signal transmitted from the transceiver, and the power supply supplies direct current to each circuit of the transponder. Further, the energization control unit controls on / off of energization from the power supply to at least one circuit according to a reception signal output from the transmission unit.

Further, in the power supply control device for the non-contact data communication device of the present invention, the transmitter of the transceiver transmits a specific frequency signal as a signal for controlling the power on / off of the responder. Further, as the energization control unit of the transponder, the resonance circuit that resonates with the specific frequency signal transmitted by the transceiver and the energization of the power supply to at least one circuit when the specific frequency signal from the resonance circuit is supplied are turned on. And a switching element.

Further, in the power supply control device for the non-contact data communication device of the present invention, the power supply control unit of the responder is turned on / off.
An amplifier for amplifying the OFF control signal is provided, and the energization control section is always energized. Further, in the power supply control device for the non-contact data communication device of the present invention, the transmitter of the transmitter / receiver transmits an energization confirmation signal for confirming the energization state of power on / off to the responder, and the responder When the energization state transmission unit of the transmission unit receives the energization confirmation signal from the transmitter of the transceiver, the energization control unit transmits data indicating the energization state.

Further, in the power supply control device for the non-contact data communication apparatus of the present invention, at least one circuit is energized from the power supply by the reception signal output from the transmission unit by the time counting unit of the energization control unit of the responder. Keeps a certain time after it is controlled to turn on. Then, the stop control unit controls the power supply to be turned off after a certain period of time in the time counting unit to stop the energization.

Furthermore, a field effect transistor is used as the switching element. Such a power supply control device for a non-contact data communication device of the present invention, when the transceiver reads or writes data with the responder,
The transceiver sends a signal for power-on / off control to the transponder, and the transponder that receives this transmission turns on / off the direct current from the power source to at least one of the circuits (power-on / off control).・ Off control).

Therefore, at the start of data communication and at the end of communication, the transmitter / receiver controls the power on / off of the transponder, which enables reliable power saving and prevents consumption when a battery is used as the power source. As a result, the transponder is used for a long period of time. Further, the non-contact data communication device power control device of the present invention transmits a specific frequency signal as a signal for performing power on / off control, and on the responder side,
This specific frequency signal is supplied to the switching element through the resonance circuit to turn on the power supply. In this case, the specific frequency signal is set to, for example, Q times through the resonance circuit, the noise component is removed, and malfunction is reduced,
The power on is set surely.

Further, the power supply control device for the non-contact data communication device of the present invention amplifies the power supply on / off control signal transmitted from the transmitter / receiver by the transponder, and constantly energizes the power supply control unit. Therefore, even when the transceiver and the transponder are separated from each other, the transponder side can reliably receive the power-on / off control signal, and the communicable range is expanded.
Also, because the power control unit is always operating,
The OFF control signal can be taken in without fail.

Further, the power supply control device for the non-contact data communication device of the present invention, when the transponder receives an energization confirmation signal for confirming the energization state from the transceiver to the transponder, Data indicating the energized state by the power supply control unit is transmitted. Therefore, it is possible to monitor the energization state from the transceiver to the responder. As a result, the transceiver can perform an appropriate control operation according to the energization state of the responder. In particular, it becomes possible for the transmitter / receiver to reliably identify the stop of energization from the responder, and to cope with the power saving.
Further, by constantly transmitting the energization confirmation signal (command), the presence or absence of the transponder is determined, and the energization control can be quickly performed while the transceiver and the transponder are moving. That is, data communication can be processed in a short time.

Further, the power supply control device for the non-contact data communication device of the present invention performs power-off by stopping energization after a lapse of a fixed time after the power-on is controlled by the responder.
More reliable power saving is achieved, and consumption when using a battery as a power source is effectively prevented. Furthermore, the power supply control device for a non-contact data communication device according to the present invention uses a field effect transistor with a small leakage current as a switching element in the energization control unit, thereby achieving further power saving.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a power supply control device for a non-contact data communication device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a power supply control device for a non-contact data communication device of the present invention. In FIG. 1, this example includes a reader / writer 31 as a transmitter / receiver for reading out data in a contactless manner, and a data storage 32 as a responder for sending data stored in response to a request from the reader / writer 31. It is roughly configured.

When the reader / writer 31 receives a command for reading data from a host device (not shown),
A control circuit 41 that controls each circuit to execute a control of reading data from the data storage 32, a command generation circuit 42 that generates and outputs a command under the control of the control circuit 41, and a command generation circuit 42. It has a switching circuit 43 for switching and selecting a command of a power-on signal or a control signal according to an output command.

Further, a power-on signal for instructing the power-on of the data storage body 32 is generated to generate a switching circuit 43.
A power-on signal generation circuit 44 for outputting to the data memory 32 and a command signal generation circuit 45 for generating a command of a control signal for the data storage body 32 are provided. Further, a transmission section 46 that transmits data to the data storage body 32 by electromagnetic induction coupling and receives a transmission signal (modulation signal) transmitted by the data storage body 32, and a data storage body received by the transmission section 46. A demodulation circuit 47 that demodulates the transmission signal from 32 and outputs the demodulated data to the control circuit 41 is provided.

The data memory 32 includes a control circuit 51 for controlling each circuit here and a non-volatile serial EEPR.
A memory 52 that stores data to be transmitted to the reader / writer 31 and stores data from the reader / writer 31 using an OM or the like is provided. In addition, a transmission unit 53 that transmits a transmission signal from the data storage body 32 to the reader / writer 31 by, for example, electromagnetic induction coupling and receives a transmission signal (modulation signal) from the reader / writer 31.
And a demodulation circuit 54 for demodulating the modulated signal from the reader / writer 31 received by the transmission unit 53.

Further, the control circuit 51 reads out from the memory 52, and a transmission signal obtained by modulating the transmission data is transmitted by the transmission section 5.
3 includes a modulation circuit 55 for transmitting to the reader / writer 31 through 3, a power-on circuit 56 that outputs a power-on control signal corresponding to the power-on signal from the transmission unit 53, and a power source 57 using a battery. There is. In addition, the power-on circuit 56
The control circuit 51, the memory 52, the demodulation circuit 54, and the modulation circuit 55 that enclose the direct current (output voltage) from the power source 57 when the power-on control signal from the
It has a switch circuit 58 that outputs to (hereinafter, referred to as power supply on / off target circuit Cr) and stops energization by a power supply off signal from the control circuit 51.

The power-on circuit 56 and the switch circuit 58 correspond to the energization control section in the claims. FIG. 2 is a circuit diagram showing a detailed configuration example of the power-on circuit 56 in the data storage body 32 shown in FIG. In FIG. 2, the power-on circuit 56 of this example includes an amplifier 56a that outputs a power-on control signal obtained by amplifying a power-on signal from the transmission unit 53 to a switch circuit 58, and an input terminal of the amplifier 56a and ground. A resistor R provided for the bias setting
1 and a coil L1 and a capacitor C1 that are provided between the input end of the amplifier 56a and the ground to form a parallel resonance circuit for resonating and supplying the power-on signal to the frequency.
And

FIG. 3 is a circuit diagram showing a detailed configuration example of the switch circuit 58 in the data memory 32 shown in FIG. In FIG. 3, the switch circuit 58 of this example applies a DC voltage supplied from the power supply 57 as an output voltage to the power-on / off target circuit Cr in FIG. 1 to reduce the leakage current and reduce the consumption current. Type FETQ1 and FETQ
FET Q2 for performing ON / OFF driving of No. 1 is provided.

Further, FE is generated by the power-on control signal from the power-on circuit 56 and the power-off signal from the control circuit 51.
The high (H) level signal that turns on TQ2 is FETQ2
AND gate 58a and OR for outputting to the gate of
Gate 58b and resistors R2 and R for setting bias voltage
3, R4 and R5. In addition, FETQ1, Q
2. The AND gate 58a and the OR gate 58b correspond to the switching element in the claims.

Next, the operation of the first embodiment will be described. In FIGS. 1, 2 and 3, the reader / writer 3
In No. 1, when a command for reading data is input to the control circuit 41 from a higher-order device (not shown), the command generation circuit 42 is controlled to generate a command. The command generation circuit 42 generates a command and outputs it to the switching circuit 43. The switching circuit 43 includes a power-on signal generation circuit 44.
From, a power-on signal of, for example, a sine wave of frequency f0 for instructing power-on to the data storage body 32 is input.

A control signal (command) for the data memory 32 is input from the command signal generation circuit 45 to the switching circuit 43, and one of them is selected and output to the transmission section 46. For example, under the control of the control circuit 41, the command generation circuit 42 switches the transmission stop command to the switching circuit 43.
When sent to the transmission unit, the switching circuit 43 selects the transmission stop command from the command signal generation circuit 45 and outputs it to the transmission unit 46, and from there, to the transmission unit 53 of the data storage body 32, for example, electromagnetic induction using a coil. It is sent by combining. Also,
In the transmission unit 46 of the reader / writer 31, the data storage 32
The transmission signal from the transmission unit 53 is received by electromagnetic induction coupling or the like, the received signal is input to the demodulation circuit 47 and demodulated, and the demodulated data is taken in by the control circuit 41 and transferred to, for example, a host device.

Next, in the data memory 32, the switch circuit 58 and the power-on circuit 56 are constantly supplied with direct current from the power source 57. Note that the power-on / off target circuit Cr surrounded by the one-dot chain line in FIG. 1 is supplied with direct current from the power source 57 by power-on control (sequence) at the start of data communication with the reader / writer 31. With this power control,
First, at the start of data communication, the transmission unit 53 receives a power-on signal of a sine wave of frequency f0 from the reader / writer 31,
This received signal is input to the power-on circuit 56 and the demodulation circuit 54. In this case, the demodulation circuit 54 is not applied with the output voltage supplied from the power source 57 from the switch circuit 58,
Not working.

In the power-on circuit 56 shown in FIG. 2, the sine-wave power-on signal of frequency f0 is set to Q (voltage expansion rate) times in the parallel resonance circuit of the coil L1 and the capacitor C1. The harmonic components are removed, and the result is input to the amplifier 56a. A power-on control signal corresponding to the power-on signal amplified here is output from the amplifier 56a to the switch circuit 58. By the power-on control signal, the switch circuit 58 applies the DC voltage supplied from the power source 57 as an output voltage to the power-on / off target circuit Cr in FIG. As a result, the data storage 32
The energization is completed for all the circuits and the operating state is reached.

The structure of the power on / off control signal and its transmission / reception will now be described. FIG. 4 is a diagram showing the structure of the power-on / off control signal (power-supply control command) and its transmission / reception state. In FIG. 4, the power-on / off control signal is composed of a signal transmitting section, a signal transmitting / receiving section, and a no-signal state section. The signal writer is the reader / writer 31,
For example, 10-bit data B ₀ , B ₁ , B ₂ , B ₃ ...
The predetermined data of B ₉ is modulated and continuously transmitted. The predetermined data is received by the data storage 32 and returned with a certain time delay, but is not received by the data storage 32.

The signal transmitting and receiving unit is a reader writer 31 modulates a predetermined data _{B 0, B 1 ... B 9} , one bit is transmitted to the data storage 32, data storage member 3 to the transmission stop period
The data returned from No. 2 is received, and this transmission / reception is repeated for a predetermined number of bits. For example, if the transmission time of the signal transmitting unit is t (s), the state of the signal transmitting / receiving unit is 2
t (s), 3t (s) in the no-signal state part.

Here, the data "0" is referred to as "signal transmitting section + signal transmitting / receiving section + no signal state section", and the data "0" is referred to as "no signal state section + signal transmitting section + signal transmitting / receiving section".
This data "0, 1" is continuous or data "0101 ..."
Is the power on / off control signal. Therefore, cycle 6
At t (s), a signal is taken out by the power-on circuit 56 of the data storage body 32, and the switch circuit 58 can be turned on by this signal.

In the switch circuit 58 shown in FIG. 3, the AND gate 58a and the OR gate 58b are used when the power-on control signal is at a low (L) level, that is, when non-data communication is started in which the power-on signal from the reader / writer 31 is not transmitted. Does not output the ON drive signal to the gate of FET Q2 from F
The ETQ1 also turns off, and the output voltage is not applied to the power-on / off target circuit Cr in FIG.

At the start of data communication in which the power-on signal is transmitted from the reader / writer 31, the OR gate 58b is used.
When the input of becomes high level and exceeds the threshold level, a high level signal is output from the output end to the gate of FET Q2, and this FET Q2 is turned on. Further, the FET Q1 is turned on by the voltage drop across the resistor R3, and the output voltage is applied to the power-on / off target circuit Cr in FIG.

The power-off signal from the control circuit 51 is normally set to a high level so that the output of the AND gate 58a becomes a high level when the output voltage is sent out. Therefore, even if the power-on signal (power-on control signal) from the reader / writer 31 is stopped, the output of the OR gate 58b maintains the high level and the output voltage is maintained. Then, when the data communication is completed, the control circuit 51 sets the power-off signal to the low level as described below, and as a result, the FETs Q1 and Q2 are turned off and the output voltage is stopped. This switch circuit 5
8 uses MOS type FETs Q1 and Q2 with a small leakage current, and the current consumption when a voltage is constantly applied is reduced.

After the power-on signal is transmitted from the reader / writer 31 and all the circuits of the data memory 32 are operated, the reader / writer 31 transmits a communication command, and this transmission signal is transmitted through the transmission section 53 to the demodulation circuit 54. And is demodulated. This demodulated data is the control circuit 5
The control operation is performed according to this communication command. When the communication command is to read data from the data memory 32, the control circuit 51 reads the data stored in the memory 52 and transfers it to the modulation circuit 55.

The data modulated here is transmitted to the reader / writer 31 through the transmission unit 53. When this data communication is completed, the control circuit 41 of the reader / writer 31 recognizes the end of this data communication, controls the command signal generation circuit 45, and sends a power off signal to the data memory 32. This power off signal is transmitted to the data storage body 32 through the transmission unit 46. The power-off signal is received by the transmission unit 53 of the data memory 32, and the received signal is input to the control circuit 51 through the demodulation circuit 54. Control circuit 51
Outputs a low-level power-off signal to the switch circuit 58.

As described above, in the first embodiment, the power-on signal is transmitted from the reader / writer 31 to the data storage body 32 at the start of data communication, and the power-on / off target circuit Cr in FIG. Then, the direct current from the power source 57 is supplied from the switch circuit 58 to be in the operating state, and then the data communication is performed. When the data transmission is completed, the data storage 32 is read from the reader / writer 31.
A power-off signal is transmitted to the switch circuit 58, and the DC output from the switch circuit 58 is stopped. Therefore, while data communication is not performed, the power supply to the power-on / off target circuit Cr in FIG. 1, which consumes a relatively large amount of current, is stopped. For example, as described above with reference to FIG. 8, more reliable power saving is achieved against reduction in current consumption only by resetting the control circuit, and battery consumption of the power source 57 is prevented, resulting in data The memory 32 can be used for a long period of time.

Next, a second embodiment will be described. In the second embodiment, control is performed to monitor the energization state of the power source 57 in the data storage body 32 from the reader / writer 31. FIG. 5 is a block diagram showing the configuration of the second embodiment. In FIG. 5, in this second embodiment, FIG.
3 to the configuration of the first embodiment shown in FIG. 3, the switch circuit 58 in the data storage body 32 is turned on / off by the control of the control circuit 41 in the reader / writer 31, that is, the direct current from the power source 57 is applied. 1 is provided with a power supply confirmation signal generation circuit 60 that generates a power supply confirmation signal for confirming whether power is turned on or off to the power-on / off target circuit Cr and outputs it to the switching circuit 43. Other configurations are the same as those of the first embodiment.

In the data memory 32, a signal for confirming the on / off state of the switch circuit 58 from the power supply confirmation signal received by the transmission section 53 is transmitted through the transmission section 53 to the reader / writer 31.
There is provided a power supply confirmation circuit 61 for transmitting to the. Other configurations are the same as those of the first embodiment. The power supply confirmation signal has the same data structure as that described with reference to FIG. 4, and the transmission / reception processing thereof is also the same.

Next, the operation of the second embodiment will be described. The operation of the second embodiment is basically the same as that of the first embodiment, but here, the data storage unit 32 is used.
A control to monitor the energization state of is added. First, in the reader / writer 31, the control circuit 41 controls the power supply confirmation signal generation circuit 60 to turn on the switch circuit 58 in the data storage body 32 under the control (sequence) corresponding to this operation.
A power supply confirmation signal for confirming the off state is generated and output to the switching circuit 43. Further, under this control, the command generation circuit 42 outputs a command to the switching circuit 43, selects this power supply confirmation signal, and transmits the data storage 3 through the transmission unit 46.
Send to 2.

In the data memory 32, the reader / writer 31
The transmission unit 53 receives the transmission signal (power confirmation signal) from the transmission unit 53. The power supply confirmation signal from the transmission unit 53 is the power supply confirmation circuit 61.
Is input to the switch circuit 58 to confirm whether the switch circuit 58 is on or off. That is, in the standby state, the switch circuit 58 is in the off state, the direct current from the power source 57 is not supplied to the power source on / off target circuit Cr in FIG.
The power-off state is confirmed by the power source confirmation circuit 61, and the signal is transmitted to the reader / writer 31 through the transmission unit 53.

The power-off confirmation signal from the data memory 32 is received by the transmission section 46 of the reader / writer 31, and is received by the control circuit 41 through the demodulation circuit 47. Control circuit 4
After setting the power-off in the data storage body 32, the control unit 1 controls the power-on for starting the data communication as described in the first embodiment. This power-on signal is transmitted to control the energization of the data memory 32 to the power-on / off target circuit Cr in FIG.

After transmitting the power-on signal, the reader / writer 31 again performs energization monitoring control on the data storage body 32, and confirms energization in the data storage body 32. Here, if the switch circuit 58 is off in the data storage body 32 due to a communication error or the like (the power-on / off target circuit Cr in FIG. 1 is not energized), the power-on is controlled again.

When the control circuit 41 of the reader / writer 31 recognizes that the switch circuit 58 in the data storage body 32 is turned on by this power-on control, a power-on signal is transmitted. After confirming that the power is turned on, data communication is executed, and at the end of the data communication, the reader / writer 31 transmits a power off signal to the data storage body 32, and further, monitors the power off state of the data storage body 32. When control is performed and the control circuit 41 of the reader / writer 31 recognizes the non-energization, the communication between the reader / writer 31 and the data storage body 32 ends.

In the second embodiment, the power supply confirmation circuit 61 is always energized. However, in order to save more power, the power supply confirmation circuit 61 may be deenergized. In this case, a passive element such as a delay line that operates without electricity is used for the active element. Further, when the power supply confirmation circuit 61 is always energized, the reader / writer 31 sends a power supply confirmation signal by a data string for executing the monitoring control for confirming the energization.
You may make it transmit from.

Further, the power supply confirmation circuit 61 confirms the on / off state of the switch circuit 58, that is, the power supply on / off state of the direct current from the power source 57 to the power on / off target circuit Cr in FIG. However, it is possible to check the energization from other circuits. For example, the switch circuit 58 and the control circuit 51
It is also possible to confirm the energization of the power on / off based on the control signal sent by the.

As described above, in the second embodiment, the energization state of the power source 57 in the data storage body 32 is monitored from the reader / writer 31 and the reader / writer 31 is detected according to the energization state.
Is in control operation. In particular, it becomes possible for the reader / writer 31 to reliably identify the stop of energization from the data storage body 32 and to cope with the power saving. In addition, by constantly transmitting the energization confirmation signal, the presence or absence of the data storage body 32 is determined, and the energization control is quickly performed while the reader / writer 31 and the data storage body 32 are moving, and the data communication is completed in a short time. To do.

Next, a third embodiment will be described. In the third embodiment, the reader / writer 31 controls the power-off of the data storage body 32 after a fixed time. FIG. 6 is a block diagram showing the configuration of the third embodiment. In FIG. 6, the reader / writer 31 is the same as that shown in FIGS.
The same as the first embodiment shown in FIG. A power-off circuit 6 that outputs a power-off signal to the switch circuit 58 by the control signal from the control circuit 51 and controls the data memory 32 to be turned off.
2 are provided. Other circuits are the same as those in the first embodiment shown in FIGS. 1 to 3.

FIG. 7 is a block diagram showing a detailed configuration example of the power-off circuit 62 in FIG. In FIG. 7, the power supply off circuit 62 of this example counts the oscillation circuit 62a that oscillates a signal for timekeeping and the oscillation signal of this oscillation circuit 62a, and stops the counting operation by the clear control signal from the control circuit 51. And a logic circuit 62c that decodes the count value of the count circuit 62b and outputs a power-off signal to the switch circuit 58 when the time of the preset count value is measured.

Next, the operation of the third embodiment will be described. The operation of the reader / writer 31 is the same as that of the first embodiment shown in FIGS. 1 to 3. In the data memory 32, when the power-on control from the reader / writer 31 energizes the power-on / off target circuit Cr in FIG. 1 to turn on the power, the control circuit 51 sends a clear control signal to the power-off circuit 62. Is output. In the power-off circuit 62, the count circuit 62b counts the oscillation signal of the oscillation circuit 62a, the count value is decoded by the logic circuit 62c,
A power-off signal is output to the switch circuit 58 when the time of a preset count value is measured. Switch circuit 58
Is turned off, and the energization for applying the output voltage to the power-on / off target circuit Cr in FIG. 1 is stopped. Further, the count circuit 62b clears the count value at the appropriate time by the clear control signal from the control circuit 51 so that the next operation can be performed.

In the third embodiment, the control circuit 51
The clear circuit control signal clears the count circuit 62b in the power-off circuit 62, but the power-off in the data storage body 32 may be controlled after a certain period of time by stopping other operations. For example, reading may be stopped in the memory 52 under the control of the control circuit 51, or a timer circuit may be provided in the switch circuit 58 for counting a certain time after which it is turned off.

Further, the same operation is performed by using a clock signal such as a clock generator for the control circuit 51 in place of the oscillation signal output from the oscillation circuit 62a. Further, as the power supply off circuit 62, an analog switch such as an integrator circuit which is turned on / off by an integrated value may be used. in this way,
In the third embodiment, the data storage 32
The reader / writer 31 controls the power-off in
More reliable power saving is achieved, and consumption when using a battery as a power source is effectively prevented.

Next, a fourth embodiment will be described. In the fourth embodiment, when controlling the power-off in the first to third embodiments, the control circuit 51 controls the power-off to the switch circuit 58 by the data string command demodulated by the demodulation circuit 54. Other circuit configurations are used for the configuration. For example, instead of the data string command, a power-off control circuit that sets the switch circuit 58 to power-on with a sine wave signal of frequency f0 is used. This power-off control circuit has the same configuration as the power-on circuit 56 shown in FIG.
8 may be configured to be turned on. In this case also, the operation is the same as in the first to third embodiments,
The data processing scale is reduced as compared with the data processing using the data string command.

In the first to fourth embodiments, if the data storage body 32 does not exist within the communicable range of the reader / writer 31, no data is returned, so that the existence of the data storage body 32 can be confirmed. . In the second embodiment, the reader / writer 31 is provided with the power supply confirmation signal generation circuit 60, the data storage body 32 is provided with the power supply confirmation circuit 61, and the power supply confirmation signal monitors the energization state of the power supply 57. Other configurations may be used. For example, data storage 3
When 2 is present in the communication area of the reader / writer 31, the same data as the normal transmission data is returned, so after the switch circuit 58 is set to ON, the phase of the return data is controlled by the control circuit 51 or the like. The signals are alternately inverted 180 degrees and transmitted to the reader / writer 31, and the phase inversion is judged by the control circuit 41 of the reader / writer 31, whereby the switch circuit 58 is turned on, that is, the power source on / off target circuit Cr in FIG. To be able to recognize the energization to.

[0058]

As is apparent from the above description, according to the power supply control device for the non-contact data communication device of the present invention, the transmitter / receiver transmits a signal for controlling the power on / off of the responder, In the responder receiving this transmission, the power on / off control for at least one circuit is performed, so the power on / off for the responder is controlled from the transceiver at the start and end of the data communication, Reliable power saving will be possible. As a result, consumption of a battery as a power source is prevented, and as a result, the transponder can be used for a long period of time.

Further, according to the power supply control device for the non-contact data communication device of the present invention, a specific frequency signal is transmitted to the transponder as a signal for performing power on / off control, and the specific frequency signal is passed through the resonance circuit. Since the power is turned on by supplying it to the switching element, the specific frequency signal is reliably extracted through the resonance circuit, the noise component is removed, malfunctions are reduced, and the power on can be reliably set. Like

Further, according to the power supply control device for the non-contact data communication device of the present invention, the power supply on / off control signal transmitted from the transmitter / receiver is amplified by the responder, and the power supply control unit is always energized. Therefore, even when the transceiver and the transponder are separated from each other, the transponder side can reliably receive the power-on / off control signal, and the communicable range is expanded. In addition, since the power supply control unit is always operating, the power supply on / off control signal can be surely taken in.

According to the power supply control device for the non-contact data communication device of the present invention, the responder from the transceiver is
When the responder receives an energization confirmation signal for confirming the energized state, when the responder receives data indicating the energized state by the power supply control unit, the transmitter / receiver monitors the energized state for the responder. As a result, the transceiver can perform an appropriate control operation according to the energization state of the responder. Further, by constantly transmitting the energization confirmation signal, the presence or absence of the transponder is determined, and the energization control can be quickly performed while the transceiver and the transponder are moving. That is, data communication can be processed in a short time.

Further, according to the power supply control device for the non-contact data communication device of the present invention, the power supply is turned off to stop the energization after a lapse of a certain time after the power supply is controlled to be turned on by the responder, so that a reliable power saving is achieved. Electricity can be achieved, and consumption of a battery as a power source can be effectively prevented. Furthermore,
According to the power supply control device for a non-contact data communication device of the present invention, a field effect transistor with a small leakage current is used as a switching element in the energization control unit, and power saving can be further achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a power supply control device for a non-contact data communication device of the present invention.

FIG. 2 is a circuit diagram showing a detailed configuration example of a power-on circuit in the data storage body in FIG.

3 is a circuit diagram showing a detailed configuration example of a switch circuit in the data storage body in FIG.

FIG. 4 is a diagram showing a configuration of a power on / off control signal and a transmission / reception state thereof in the first embodiment.

FIG. 5 is a block diagram showing a configuration of a second embodiment.

FIG. 6 is a block diagram showing a configuration of a third embodiment.

7 is a block diagram showing a detailed configuration example of a power-off circuit in FIG.

FIG. 8 is a block diagram showing a configuration of a conventional power supply control device for a non-contact data communication device.

[Explanation of symbols]

 31: reader / writer 32: data storage body 41, 51: control circuit 42: command generation circuit 43: switching circuit 44: power-on signal generation circuit 45: command signal generation circuit 46, 53: transmission unit 47, 54: demodulation circuit 52 : Memory 55: Modulation circuit 56: Power supply on circuit 56a: Amplifier 57: Power supply 58: Switch circuit 60: Power supply confirmation signal generation circuit 61: Power supply confirmation circuit 62: Power supply off circuit C1: Capacitor L1: Coil

Claims (6)

[Claims] 1. A power supply control device for a non-contact data communication device, wherein a transmitter / receiver reads / writes data from / to a responder, and the transmitter / receiver controls power on / off of the responder. The transmitter / receiver includes a transmitter that transmits a signal for performing power on / off control for the transponder, and the transponder receives the power on / off control signal transmitted from the transceiver. A transmission unit, a power supply for supplying direct current to each circuit of the transponder, and an energization control unit that performs on / off control of energization from at least one circuit by a reception signal output by the transmission unit. A power supply control device for a non-contact data communication device, comprising: 2. The power supply control device for a non-contact data communication device according to claim 1, wherein the transmitter of the transmitter / receiver transmits a specific frequency signal as a signal for controlling power on / off of the responder. In addition, as the energization control unit of the responder, a resonance circuit that resonates with a specific frequency signal transmitted by the transceiver, and a specific frequency signal from the resonance circuit is supplied from at least one circuit from a power source. A power supply control device for a non-contact data communication device, comprising: a switching element that turns on electricity. 3. The power supply control device for a non-contact data communication device according to claim 1, wherein the energization control section of the responder is provided with an amplifier for amplifying a power supply on / off control signal, and the energization control is performed. A power supply control device for a non-contact data communication device, which constantly energizes a section. 4. The power supply control device for a non-contact data communication device according to claim 1, wherein the transmitter of the transmitter / receiver energizes the transponder to confirm a power-on / off energization state. Along with transmitting the confirmation signal, the transmission unit of the responder comprises an energization state transmission unit that transmits data indicating the energization state by the energization control unit when receiving the energization confirmation signal from the transmitter of the transceiver. A power control device for a non-contact data communication device, characterized in that 5. The power supply control device for a non-contact data communication device according to claim 1, wherein the energization control unit of the responder receives at least one circuit from the power supply by a reception signal output from the transmission unit. And a stop control unit for controlling power-off to stop energization after a certain period of time has passed in the time counting unit. A power supply control device for a non-contact data communication device. 6. The power supply control device for a non-contact data communication device according to claim 2, wherein at least a field effect transistor is used as the switching element.