JP4603984B2 - COMMUNICATION DEVICE AND ITS CONTROL METHOD - Google Patents

Description

  The present invention relates to a communication apparatus that performs wireless communication by supplying power from an external device using, for example, electromagnetic coupling, and a control method thereof.

In recent years, battery-powered devices such as digital cameras, mobile phones, and PDAs (personal digital assistants) have become widespread. However, the power consumption of these devices is required to be as small as possible due to the extended operating time of the battery. Further, in recent years, when performing automatic ticket gate processing using a commuter pass composed of an IC card or the like and entry / exit processing using an ID card, wireless communication is performed between the card and the gate using a non-contact short-range wireless system. A system has been proposed (see Patent Document 1). In such a wireless system, a device (initiator) that starts communication transmits a power carrier wave to a device (target) that is called. In the target, electromagnetic induction is performed by the received power carrier wave, and the electromotive power is supplied as power supply power. In the example of an automatic ticket gate, electric power is supplied from a gate side to a card having no power source by electromagnetic induction. When the card is held over the gate, power is excited in the card and the card becomes operational.
JP 2000-137774 A (summary)

  In such a communication system, the communication activation request side (initiator) needs to supply power to the communication partner (target). When the device driven by the battery is the activation request side, it is necessary to supply power from the device to the target, and it is difficult to save power consumption, and the driving time by the battery is shortened.

  The present invention has been made in view of the above-described conventional example, and provides a communication device and a control method thereof that can save power consumption by enabling communication in a passive mode even when an operation is started as an initiator. The purpose is to do.

In order to achieve the above object, the present invention has the following configuration. That is, a communication unit that communicates by switching the active mode which is operated by power from the power supply unit, a passive mode of operation with electromotive by the received carrier,
Before Symbol requests communication in the active mode to the communication partner device by the communication unit in the active mode, in response to the response pairs to the request, to a control unit for said communication means to the passive mode It is characterized by.

  According to the present invention, it is possible to reduce power consumption for communication by using the power of the communication partner during communication.

<Configuration of communication device>
Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the wireless terminal 1. In FIG. 1, an operation unit 101 is an operation unit for performing operation instructions such as data transmission and printing from a user. The power supply unit 102 is a main power supply of the apparatus, and is a battery in this embodiment. The switch 103 is controlled by operating the operation unit 101 and is a switch for turning on / off the power supply from the power supply unit 102 to the electromagnetic coupling type wireless unit 112. The switch 104 is controlled by the CPU 105 in the electromagnetic coupling type radio unit 112 and is a switch for turning on / off the power supply from the power source unit 102 to the radio unit 112. The switch 103 is a switch that can be switched between the operation unit 101 and the CPU 105. The operation can be switched on and off by either operation. In other words, it corresponds to a set of three-way switches. Therefore, the CPU 105 and the operation unit 101 can switch between the energized state and the cut-off state of the switch 103 by toggling the respective control signals. The switch 104 is a switch that can be switched between energization and cutoff by the output signal of the rectifying and smoothing circuit 109. If power is supplied from the rectifying / smoothing circuit 109, the switch 104 is cut off, otherwise it is energized. The CPU 105 is a processor that controls the electromagnetic coupling type radio unit 112. The memory 106 stores programs, data, and the like for realizing the procedure of FIG. Further, mode information 106 a indicating either an active mode or a passive mode described later is also stored in the memory 106. It is desirable that programs and data are stored in a nonvolatile memory. The carrier detection unit 107 detects a carrier (radio wave) in the space. The antenna coil 108 is an antenna coil for generating power by transmitting / receiving a carrier or by electromagnetic induction from the carrier. The rectifying / smoothing circuit 109 is a rectifying / smoothing circuit for converting the electric power generated by the electromagnetic induction of the antenna coil 108 into a DC voltage. The modem circuit 110 modulates data to be transmitted and demodulates the received data. The oscillator 111 is an oscillator for generating a carrier signal. The electromagnetic coupling type radio unit 112 includes blocks 105 to 111.

<Operation of communication device>
Hereinafter, the operation of the wireless terminal 1 will be described with reference to FIG. 2 is implemented by a program executed by the CPU 105. FIG. 2 includes steps performed in blocks other than the CPU, such as carrier detection and transmission. These steps are also included in FIG. 2 because they are executed under the control of the CPU. Here, the operation mode in which the radio unit 112 is driven by the power generated from the received carrier to transmit / receive data is referred to as a passive mode. In addition, the operation of releasing carriers by itself is called an active mode.

  The communication device 1 is initially waiting for an instruction input from the operation unit 101 (S201). If there is an input from the operation unit 101 (S202-YES), the presence / absence of a carrier signal is detected (S203). In step S204, the presence / absence of a carrier signal is determined. If there is a carrier, the process branches to step S205, and if not detected, the process branches to step S206. If a carrier signal is detected without input from the operation unit 101, the process may proceed to step S205.

  The power supply to the wireless unit 112 in step S203 will be described below. First, in an initial state, the switch 103 is in a cut-off state, and power from the power supply unit 102 is not supplied to the wireless unit 112. When the switch 103 is switched by operating the operation unit 101, power is supplied from the power supply unit 102 to the wireless unit 112 according to the state of the switch 104. When there is no carrier in the space, electromagnetic induction by the antenna coil 108 is not generated, and thus power is not supplied from the rectifying and smoothing circuit 109 to the CPU 105. Therefore, the switch 104 is in an on (energized) state. Therefore, when no carrier is detected, power is supplied to the wireless unit 112 from the power supply unit 102 of the apparatus main body. On the other hand, when there is a carrier in the space, electromagnetic induction is generated by the antenna coil 108, and power is supplied to the wireless unit 112 through the rectifying and smoothing circuit 109, so that the switch 104 is off (cut off). Therefore, even if an operation input is performed on the operation unit 101 and the switch 103 is turned on, power is not supplied from the power supply unit 102 of the apparatus main body.

  If it is determined in step S205 that there is a carrier signal, data in the memory 106 is transmitted using the power generated from the carrier (S205). Details of the data transmission processing in step S205 will be described below. Electric power is supplied to the wireless unit 112 via the rectifying and smoothing circuit 109 by electromagnetic induction of the antenna coil 108. The CPU 105 reads the data in the memory 106, performs predetermined modulation by the modulation circuit 110, superimposes the data on the carrier, and radiates it from the antenna coil 108 to the space. If necessary, processing such as encryption is performed together with modulation.

  When it determines with there being no carrier signal in step S204, it changes to active mode and transmits a carrier from the antenna coil 108 (S206). At the time of transition of the communication mode, the CPU 105 records data corresponding to the mode after the transition (active mode or passive mode) in the mode area 106 a of the memory 106. In this case, data indicating the active mode is recorded in the mode area 106a. As for the power supply, power supply by the power supply unit 102 is necessary for communication in the active mode. Therefore, the energized state of the switch 104 is maintained. Since there is no carrier, the switch 103 is in an energized state.

  Next, in step S207, an “activation request” is transmitted to the communication partner, and a response wait state is entered (S208). The activation request in step S207 is a signal that requests the communication partner to enter the active mode. In step S209, it is determined whether or not there is a response. If there is no response, carrier transmission is stopped and the mode is shifted to the passive mode (S210). Along with the mode transition, data indicating the passive mode is recorded in the mode area 106a. At the same time, the switch 103 is switched to the cut-off state and the operation input is waited.

  In step S209, it can be determined that there is no response when there is no response despite the transmission of a certain number of request signals or waiting for a response for a certain time.

  If there is a response in step S209, it is determined whether this response is ACK (acceptance) or not (disapproval) (S211). If it is not an acceptance response, the data is transmitted in the active mode (S214). After data transmission, the mode shifts to the passive mode (S215) and waits for an operation input. The contents of this process are the same as in step S210.

  When it is determined in step S211 that the response is an acceptance response, carrier transmission is stopped and the mode is shifted to the passive mode (S212). The contents of this process are the same as in step S210. As a result, the switch 103 is turned off, and power supply to the wireless unit 112 is stopped. When the communication partner starts transmission in the active mode, the wireless unit 112 is driven by power generated by the carrier. Thereby, the wireless unit 112 transmits data (S213).

  The operation process in step S213 is basically the same as step S205. However, in step S213, a transmission completion signal is added after the transmission data ends. In the case of step S205, it is considered that the communication partner is always operating in the active mode. On the other hand, in the case of step S213, the communication partner is normally in the passive mode, and after receiving the data transmitted in step S213, it is necessary to shift to the passive mode again. Therefore, a transmission completion signal is added in step S213 in order to clearly indicate the cause of the mode transition to the communication partner. Note that a transmission completion signal can be transmitted in step S205. In this case, there is no need to change the other party's process.

  FIG. 4 shows an example of a processing procedure of a terminal that is a communication partner of a terminal that performs communication control according to the procedure of FIG. This terminal also has the configuration shown in FIG. However, the power supply unit 102 may be an AC power supply. When a carrier is detected in the passive mode, the message is received to determine whether it is a start request message (S401). Next, if it is an activation request, it shifts to the active mode and switches the switch 103 to the energized state. Since the switch 104 is also energized when there is no carrier from the other party, the terminal is driven by the power supply unit 102. In step S403, a message for urging data transmission is transmitted on the power carrier to the communication partner terminal. In step S404, data from the other party is received in the active mode. In step S405, the communication mode is returned to the passive mode. In step S406, if there is more data to be received, the data is received in the passive mode.

  FIG. 3 shows a series of processing sequences of S201, S203, S206, S207, S208, S212, and S213 in FIG. 2 as a procedure by the terminal A, and a process in FIG. Terminals A and B are initially in passive mode. Terminal A is the wireless terminal shown in FIG. The terminal B can perform communication operation in either the active mode or the passive mode, and is normally a terminal that operates in the passive mode. If the message received in the passive mode is “start-up request”, the terminal B changes the communication mode from the passive mode to the active mode, transmits a carrier to the terminal A, and receives data. Terminal B may have the same configuration as terminal A.

  In FIG. 3, when data is sent from the terminal A to the terminal B, the terminal A shifts to the active mode when an operation input is received (S206). Terminal A transmits an activation request 301 to terminal B in the active mode (S207). Since the terminal B that has received it operates in the passive mode, the terminal B returns an acceptance response signal (ACK) 302 using the carrier of the terminal A (S302).

  Terminal B shifts from the passive mode to the active mode when it finishes returning the ACK signal. Conversely, if the terminal A receives the ACK signal 302 from the terminal B, the terminal A shifts from the active mode to the passive mode (S212). The terminal A transmits the data 303 in the memory 106 to the terminal B using the radio wave (carrier) of the terminal B (S213). When terminal A has finished sending data 303, terminal A transmits a transmission completion signal 304 to terminal B. On the other hand, when the terminal B receives the transmission completion signal 304 from the terminal A, the terminal B shifts from the active mode to the passive mode.

  According to the above procedure, the terminal A can perform data communication without using its own power source, so that power consumption can be reduced. A similar configuration is possible even when data is sent from terminal B to terminal A.

  For example, when the terminal A is a digital camera and the terminal B is a printer, the following operation is performed. The digital camera stores the captured image data in the memory 106 in the electromagnetic coupling type wireless unit 112, which is a separate area from the main memory of the main body. At this time, the image data may be stored in both the main memory of the main body and the memory 106 in the radio unit 112 of the electromagnetic coupling method.

  In this state, an operation for instructing a print operation such as a print key is performed close to the printer apparatus. When an operation to instruct a printing operation is performed, the digital camera shifts from the passive mode to the active mode and activates the built-in electromagnetic coupling type radio unit. Then, a startup request is transmitted to the printer, and the wireless unit of the printer is switched from the passive mode to the active mode.

  When the printer switches to the active mode, the digital camera enters the passive mode, and sends data in the memory 106 to the printer using a carrier (radio wave) emitted from the printer. The printer receives a transmission completion signal of image data from the digital camera, and returns the built-in electromagnetic coupling type wireless unit to the passive mode.

  With the above procedure, data transfer from the digital camera to the printer is performed with the digital camera body turned off. For this reason, the battery consumption of the digital camera can be kept low.

  Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) consisting of a single device even if it is applied to a system composed of a plurality of devices (eg, a host computer, interface device, reader, printer, etc.). You may apply. Another object of the present invention is to supply a recording medium recording a program code for realizing the functions of the above-described embodiments to a system or apparatus, and the system or apparatus computer reads out and executes the program code stored in the storage medium. Is also achieved. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  Further, according to the present invention, an operating system (OS) running on a computer performs part or all of actual processing based on an instruction of a program code, and the functions of the above-described embodiments are realized by the processing. It is also included. Furthermore, the present invention is also applied to the case where the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. In that case, based on the instruction of the written program code, the CPU of the function expansion card or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing. .

The block diagram of the communication terminal which concerns on embodiment of this invention Wireless part operation flow chart (during transmission) Sequence diagram of radio unit mode switching operation Wireless unit operation flow chart (during reception)

Explanation of symbols

101 Main unit of operation unit 102 device,
103 Switch 104 which is turned on / off by operation of operation unit 101 Switch 105 which is ON / OFF controlled by CPU 105 CPU in wireless unit of electromagnetic coupling method
106 Nonvolatile memory 107 for storing data 107 Detecting carrier (radio wave) in space 108 Antenna coil 109 Rectifying and smoothing circuit that converts electric power generated by electromagnetic induction of antenna coil to DC voltage

Claims (5)

And an active mode which is operated by power from the power supply unit, and a communication means for communicating by switching the passive mode of operation with electromotive by the received carrier,
Before Symbol requests communication in the active mode to the communication partner device by the communication unit in the active mode, in response to the response pairs to the request, to a control unit for said communication means to the passive mode A communication device characterized by the above. Wherein, when receiving a response when or non acceptance there is no response to the request, according to claim 1, characterized in that communicating until balls to the communication unit in the active mode Communication device. It further comprises an operation means for the user to input,
Said communication means, the communication apparatus according to claim 1, the to Rukoto wherein when the operation by the operation means is performed in the active mode. A control method of a communication device that performs communication by switching between an active mode that operates by power from a power supply unit and a passive mode that operates by receiving power from a received carrier ,
A step you require communication in the active mode to the communication partner device in the active mode,
Depending on the response against the request, the control method of a communication apparatus characterized by comprising a step of switching to the passive mode. A program for controlling a communication device that communicates by switching between an active mode that operates by power from a power supply unit and a passive mode that operates by receiving power from a received carrier ,
Requesting communication in the active mode to the communication partner device in the active mode;
A program for causing a computer to execute a step of switching to a passive mode in response to a response to the request .

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