JP2013065154A - Circuit device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit device and an electronic apparatus which enable quick communication response to a power transmission device in an apparatus using electromagnetic induction.SOLUTION: A circuit device 90 includes a power management part 20 which supplies power to a system device 100 by receiving power from a power reception part 10 for receiving power by electromagnetic induction from a power transmission device 200, and a control part 79 which operates with power received by the power reception part 10 by electromagnetic induction and performs control processing. After starting with power received by the power reception part 10 by electromagnetic induction, the control part 70 performs initial communication processing with the power transmission device 200 through the power reception part 10 on behalf of the system device 100.

Description

  The present invention relates to a circuit device, an electronic device, and the like.

  In recent years, contactless power transmission (non-contact power transmission) that uses electromagnetic induction and enables power transmission even without a contact of a metal part has been in the spotlight. As an application example of this contactless power transmission, a non-contact IC card or the like that can receive power and transmit / receive information by simply holding it over a terminal device has been proposed. According to this non-contact IC card, it is possible to realize a card having functions such as electronic money, a public transportation prepaid card, and an ID card for entrance / exit management.

  On the other hand, an EPD (Electrophoretic Display) which is an electrophoretic display is known as a display device suitable for electronic paper or the like. This EPD has an advantage that power consumption can be reduced because display information can be held in a non-powered state. As a conventional technology of a portable information display device using such an EPD, there is a technology disclosed in Patent Document 1, for example.

  Now, as a system for receiving power from a power transmission device using electromagnetic induction, systems equipped with batteries (primary and secondary batteries) for system devices such as microcomputers, and such batteries are installed. A battery-less system can be considered.

  In a system equipped with a battery, the system device is ready to make a communication response to the power transmission device using the power of the battery.

  On the other hand, in a battery-less system, the system device is activated by the power received from the power transmission device, and after the activation, the system device makes a communication response to the power transmission device.

  However, mounting such a battery is easy with a portable mobile device such as that described in Patent Document 1, but there is a problem that it is difficult with a small device such as an IC card.

  In the case of a battery-less system, it takes a long time for the system device to be activated by the power received from the power transmission device and to make a communication response to the power transmission device. Accordingly, there is a problem that the polling period needs to be extended in order to ensure the time required for the power transmission device such as the reader / writer to detect the power receiving device.

  And if the polling period becomes longer in this way, wasteful power consumption due to polling will increase. On the other hand, if the polling period is shortened to reduce power consumption, if the system device cannot respond within the polling period, a reset operation may occur repeatedly due to unsuccessful polling, and the target operation can be executed. It will disappear.

JP 2008-17592 A

  According to some aspects of the present invention, it is possible to provide a circuit device, an electronic device, and the like that enable an early communication response to a power transmission device in a device using electromagnetic induction.

  One embodiment of the present invention includes a power management unit that receives power from a power receiving unit that receives power from a power transmission device by electromagnetic induction and supplies power to a system device, and power that is received by the power receiving unit by electromagnetic induction. And a control unit that performs control processing, and the control unit starts up with power received by the power receiving unit by electromagnetic induction, and then performs initial communication processing with the power transmission device via the power receiving unit. The present invention relates to a circuit device performed in place of the system device.

  In one embodiment of the present invention, power is supplied from electric power received from a power transmission device by electromagnetic induction, and a system device operates. In this case, when the control unit is activated by the received power, the control unit executes initial communication processing with the power transmission device instead of the system device. As a result, a communication response by the initial communication process is possible without waiting for the system device to be activated. Therefore, it is possible to provide a circuit device that enables an early communication response to the power transmission device in a device using electromagnetic induction.

  In one aspect of the present invention, the control unit performs initial communication processing with the power transmission device via the power reception unit before the system device that has received power supply from the power management unit is activated. It may be performed on behalf of the system device.

  In this way, the initial communication process can be executed by the control unit even after the power is received by the power receiving unit, even when the system device is not yet activated, thereby enabling an early communication response to the power transmission device. Become.

  In the aspect of the invention, the power management unit may supply power to the system device based on the power received by the power receiving unit after the control unit performs the initial communication process. .

  According to this configuration, after the initial communication process is performed by the control unit, power based on the power received by the power receiving unit is supplied to the system device, and the system device is activated. And it becomes possible to perform the data communication process etc. between a power transmission apparatus and a system device.

  In one aspect of the present invention, the control unit includes a host interface that is communicatively connected to a power receiving unit side host interface provided in the power receiving unit and a system device side host interface provided in the system device, The host interface may perform initial communication processing for the power receiving unit side host interface instead of the system device side host interface after being activated by the power received by the power receiving unit.

  In this way, the host interface of the control unit can be operated as if it is a system device side host interface, and the initial communication process with the power receiving unit side host interface can be executed.

  In the aspect of the invention, the control unit may include a register that notifies the system device that the initial communication processing has been performed on behalf of the system device.

  In this way, the system device can confirm whether the initial communication processing has already been performed by the control unit by performing the read operation of the register, and can execute the subsequent processing.

  In the aspect of the invention, the control unit may perform a process of transmitting an initialization parameter to the power receiving unit as the initial communication process.

  This makes it possible to execute processing necessary for initialization, such as determination of system compatibility, using the initialization parameter transmitted to the power receiving unit by the initial communication processing.

  In one aspect of the present invention, the power receiving unit that has received the initialization parameter receives a polling command from the power transmitting device, and the power receiving unit transmits a polling response to the power transmitting device. Data communication may be performed with the device via the power receiving unit.

  In this way, it is possible to determine the suitability of the system by receiving the polling command from the power transmission device and transmitting the polling response to the power transmission device, and to execute the data communication processing as the subsequent processing. .

  In one aspect of the present invention, the power management unit performs control to accumulate charges in the charge accumulation unit during the data communication period, and supplies the power source based on the charges accumulated in the charge accumulation unit. You may supply with respect to the said system device in the period after completion | finish of the power reception by a power receiving part.

  In this way, it is possible to store charges in the charge storage unit by effectively utilizing the data communication period. Then, even after the power reception of the power receiving unit is completed, it is possible to supply the system device with the power based on the charge stored in the charge storage unit to operate the system device.

  In the aspect of the invention, the power management unit may receive a power from the power reception unit, and may control the first charge accumulation unit to accumulate charges, and the first accumulation control unit. And a power supply unit that supplies power to the system device based on the charge stored in one charge storage unit.

  In this way, the electric charge from the power receiving unit is accumulated in the first charge accumulating unit, and the power source based on the accumulated charge is supplied to the system device even after the power receiving unit receives power, for example, It becomes possible to operate the system device.

  According to another aspect of the present invention, the second charge accumulation unit includes a second accumulation control unit that receives electric power from the power reception unit and performs control to accumulate charges in the second charge accumulation unit. Is a charge storage unit for system startup having a charge storage capacity smaller than that of the first charge storage unit, and the power supply unit receives the second charge during system startup after power reception by the power reception unit. A power source based on the stored charge of the storage unit may be supplied to the system device and the control unit.

  In this way, even when the storage capacity of the first charge storage unit is large, power based on the stored charge of the second charge storage unit for system startup is supplied to the system device and the control unit at an early stage. become able to. Therefore, it is possible to provide a circuit device or the like that enables the system to be activated in a short power reception period in a device using electromagnetic induction.

  In the aspect of the invention, the power supply unit is provided between the first storage node and the connection node of the first charge storage unit, and travels from the first storage node to the connection node. A first diode whose direction is a forward direction and a direction from the second storage node to the connection node provided between the second storage node and the connection node of the second charge storage unit; The power supply unit may supply power to the system device and the control unit based on the voltage of the connection node.

  In this way, the rectifying function of the first and second diodes can be effectively used to supply the power supply voltage based on the accumulated charges of the first and second charge accumulation units to the system device and the control unit. It becomes like this. In addition, if the first and second diodes are used in this way, a control signal for switching operation can be made unnecessary, so even if it is difficult to generate such a control signal before starting the system, It becomes possible to respond.

  In the aspect of the invention, the power supply unit may supply power to the system device based on the accumulated charge of the first charge accumulation unit in a period after the end of power reception by the power reception unit. Good.

  In this way, the electric charge from the power receiving unit is accumulated in the first charge accumulating unit, and the power source based on the accumulated charge is supplied to the system device even after the power receiving unit receives power, for example, It becomes possible to operate the system device.

  In one aspect of the present invention, the system device performs display control processing of an electrophoretic display unit that displays an image, and the first accumulation control unit performs at least one display rewrite of the electrophoretic display unit. Control for accumulating necessary electric charge in the first electric charge accumulating unit may be performed.

  Thus, if the amount of charge stored in the first charge storage unit is limited to the charge required for at least one display rewrite of the electrophoretic display unit, the storage capacity of the first charge storage unit is reduced. You don't have to make it big. As a result, charge accumulation in the first charge accumulation unit can be completed in a short time, and it is possible to cope with a case where a short power reception period is required.

  Another aspect of the invention relates to an electronic apparatus including any one of the circuit devices described above and the system device.

  In another aspect of the present invention, the system device may perform display control processing of an electrophoretic display unit that displays an image.

  If the electrophoretic display unit is used as the display unit in this manner, display information can be held in a non-powered state, and convenience and the like can be improved.

  In another aspect of the present invention, the system device is supplied with power based on the charge accumulated in the charge accumulating unit in the power receiving period of the power receiving unit, and the electrophoretic display unit in the display rewriting period after receiving power The display rewriting process may be performed.

  In this way, for example, data can be received during the power reception period, and display rewrite processing of the electrophoretic display unit can be executed based on the received data during the subsequent display rewrite period.

2 is a basic configuration example of a circuit device of the present embodiment and an electronic apparatus including the circuit device. Application example to a non-contact IC card which is one of electronic devices. Explanatory drawing about the polling operation | movement of a reader / writer, and data communication by it. The operation | movement flowchart explaining the method of this embodiment. A detailed configuration example of a power management unit or the like. 6A is an explanatory diagram of the method of the comparative example, and FIG. 6B is an explanatory diagram of the method of the present embodiment. FIGS. 7A and 7B are operation explanatory views of the circuit device of this embodiment. The detailed 1st structural example of the circuit apparatus of this embodiment. FIG. 9A and FIG. 9B are operation explanatory views of the first configuration example. The detailed 2nd structural example of the circuit apparatus of this embodiment. The detailed 3rd structural example of the circuit apparatus of this embodiment. A configuration example of a system device. 13A to 13C are explanatory diagrams of an electrophoretic display unit.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

1. 1. Basic Configuration of Circuit Device and Electronic Device FIG. 1 shows a basic configuration example of a circuit device of the present embodiment and an electronic device including the circuit device. The circuit device 90 according to this embodiment includes a power management unit 20 and a control unit 70. The electronic apparatus according to the present embodiment includes a circuit device 90 and a system device 100. Further, the electronic device can include a power receiving unit 10 and a display unit 150 (such as an electrophoretic display unit) that receive power by electromagnetic induction. Furthermore, the electronic device can include a secondary coil L2 (a power receiving coil, a secondary inductor), a capacitor CB, a capacitor C (electric storage unit), and the like. The secondary coil L2 and the capacitor CB constitute a power receiving side resonance circuit.

  Note that the configurations of the circuit device and the electronic apparatus according to the present embodiment are not limited to the configurations shown in FIG. 1, and various modifications such as omitting some of the components or adding other components are possible. It is. For example, the system device 100 or the power receiving unit 10 may be a component of the circuit device 90. Further, as an electronic device to which the present embodiment is applied, various devices such as an IC card, an electronic shelf label, and an IC tag can be assumed.

  The power receiving unit 10 receives power transmitted from the power transmission device 200 (terminal device, charger, counterpart device) by electromagnetic induction. For example, power is received by non-contact power transmission (non-contact power transmission) that enables power transmission even without a metal part contact. Specifically, a primary coil L1 (power transmission coil, primary inductor) provided on the power transmission side and a secondary coil L2 provided on the power reception side are electromagnetically coupled to form a power transmission transformer. Thus, non-contact power transmission (contactless power transmission) is realized. The power receiving unit 10 converts the AC induced voltage of the secondary coil L2 into a DC voltage. This conversion can be realized by a rectifier circuit included in the power receiving unit 10 or the like.

  As the primary coil L1 and the secondary coil L2, for example, a planar coil can be adopted, but this embodiment is not limited to this, and the primary coil L1 and the secondary coil L2 are electromagnetically coupled to generate power. As long as it can transmit, the shape, structure, etc. are not limited.

  The power receiving unit 10 includes a communication unit 16 and a host I / F (interface) 18. The communication unit 16 performs communication processing with the power transmission device 200 that is the counterpart device. Specifically, information is transmitted / received to / from the power transmission apparatus 200 by an amplitude modulation process (frequency modulation process) or a load modulation process using the coils L1 and L2. For example, the power transmission device 200 transmits data to the power receiving unit 10 by amplitude modulation processing (or frequency modulation processing) using the coils L1 and L2. On the other hand, the communication unit 16 of the power reception unit 10 transmits data to the power transmission device 200 by load modulation processing using the coils L1 and L2. Note that data communication may be realized using the primary coil L1 and the secondary coil L2 for electromagnetic induction, or may be realized by providing another coil for communication.

  The host I / F 18 performs host interface processing with a system device serving as a host. This host interface processing is realized by a data line, a clock line, a control line, and the like.

  The system device 100 is a device that executes processing as a system of an electronic device, and can be realized by, for example, a microcomputer. The system device 100 includes a host I / F 110 and a processing unit 120.

  The display unit 150 is for displaying various images. The processing unit 120 (processor) performs display control processing for the display unit 150. As the display unit 150, for example, an electrophoretic display unit (hereinafter, appropriately referred to as EPD) can be employed, and the processing unit 120 performs display control processing of the EPD. The processing unit 120 performs various control processes necessary for system operation.

  Examples of display information on the display unit 150 include information on received data by communication, sensor detection information (information such as pressure, temperature, humidity, etc.), unique information / personal information in a memory built in the IC card, and the like.

  FIG. 2 shows an application example when the electronic device is an IC card 190. The IC card 190 is provided with a display unit 150 realized by EPD or the like so that various types of information can be displayed. The IC card 190 has a power receiving unit 10, a circuit device 90 (IC), capacitors C1 and C2, which will be described later, and the like mounted therein.

  When the user holds the IC card 190 over the terminal device 202 (power transmission device), the IC card 190 operates by receiving power from the terminal device 202 by electromagnetic induction and performs data communication with the terminal device 202. Then, images such as numbers and characters corresponding to the communication result are displayed on the display unit 150. Taking electronic money or a prepaid card as an example, the amount used, balance, etc. are displayed on the display unit 150. Various types of information are also displayed on the display unit 210 of the terminal device 202.

  FIG. 3 is an explanatory diagram of the polling operation of the reader / writer which is the terminal device 202 of FIG.

  As shown in FIG. 3, the reader / writer performs a polling operation for intermittently transmitting power every period TA. That is, the reader / writer performs temporary power transmission during the polling period TP in FIG. 3, and stops power transmission during other periods. When a touch operation is performed with the IC card 190 during the polling period TP, the IC card 190 receives power, operates based on the received power, and returns a response to the reader / writer. Become.

  For example, when a card touch is performed at G1 in FIG. 3, the polling period TP is extended as shown at G2, and data communication between the reader / writer (terminal device 202) and the IC card 190 is executed. Specifically, when the reader / writer starts polling electromagnetic induction in G3, the power supply of the IC card 190 is activated as shown in G4, and initial communication processing is performed as shown in G5. That is, initialization parameter communication processing is performed. When receiving the start of communication, the reader / writer extends power transmission as indicated by G6. As a result, data communication as shown in G7 is performed, and security information and various data (usage amount data, remaining amount data, etc.) are transmitted and received. Further, in the present embodiment, display rewriting processing of the display unit 150 (EPD) is performed as indicated by G8, and thereby the usage amount, the remaining amount, etc. can be displayed on the display unit 150 of the IC card 190.

  In this case, since the IC card 190 is battery-free, the system device 100 is activated by the power received from the reader / writer, and after activation, the system device 100 makes a communication response to the reader / writer.

  However, in the case of a battery-less system such as the IC card 190, it takes a long time for the system device 100 to be activated by the power received from the reader / writer and to make a communication response to the reader / writer. End up. Therefore, in order to ensure the time required for the reader / writer to detect the IC card 190, it is necessary to lengthen the polling period TP in FIG.

  And if polling period TP becomes long like this, useless power consumption by polling will increase. That is, since the reader / writer repeats the polling operation as shown in FIG. 3 even when the IC card 190 is not present, if the polling period TP becomes longer, the power consumption increases accordingly. On the other hand, if the polling period TP is shortened in order to save power, if the system device 100 cannot make a communication response within the polling period TP, a situation where the reset operation is repeatedly performed due to unsuccessful polling may occur.

  In order to solve the above problems, the present embodiment employs a circuit device 90 having the configuration shown in FIG. The circuit device 90 includes a power management unit 20 and a control unit 70.

  The power management unit 20 performs various management processes (control processes) for power supply. Specifically, it receives power from the power receiving unit 10 that receives power from the power transmission device 200 by electromagnetic induction, and supplies power to the system device 100.

  The control unit 70 performs various controls of the circuit device 90 of the present embodiment and performs communication control processing. For example, the control unit 70 operates with electric power received by the power receiving unit 10 by electromagnetic induction, and performs various control processes. The control unit 70 can be realized by a digital circuit such as a gate array circuit. The control unit 70 includes a host I / F 72, an activation detection unit 74, and a register unit 76.

  In this embodiment, the control unit 70 performs an initial communication process in place of the system device 100. That is, the initial communication process indicated by G5 in FIG. 3 is normally executed by the system device 100. In this embodiment, this initial communication process is performed by the control unit 70 (host I / O) provided in the circuit device 90. F72) will act for you.

  Specifically, the control unit 70 performs initial communication processing with the power transmission device 200 via the power receiving unit 10 instead of the system device 100 after being activated by the power received by the power receiving unit 10 by electromagnetic induction. Here, the initial communication process is a process of transmitting initialization parameters and the like. That is, the control unit 70 performs a process of transmitting an initialization parameter to the power receiving unit 10 as an initial communication process. For example, the control unit 70 transmits an initialization parameter to the host I / F 18 of the power receiving unit 10 using the host I / F 72 instead of the host I / F 110 of the system device 100.

  In the present embodiment, the control unit 70 performs initial communication processing with the power transmission apparatus 200 via the power receiving unit 10 before the system device 100 that receives power supply from the power management unit 20 is activated. On behalf of. For example, the initialization parameter transmitted by the host I / F 72 of the control unit 70 in the initial communication process is stored in a storage unit (not shown) of the power receiving unit 10. And the initial communication process is implement | achieved by performing the comparison process with the information of the stored initialization parameter, and the information which the power receiving part 10 received from the power transmission apparatus 200. FIG.

  The power management unit 20 supplies the system device 100 with power based on the power received by the power receiving unit 10 after the control unit 70 performs the initial communication process. For example, the power management unit 20 supplies power based on the power received by the power receiving unit 10 to the control unit 70, whereby the control unit 70 is activated and started up, and performs the initial communication process described above. Thereafter, power from the power management unit 20 is supplied to the system device 100, and the system device 100 is activated. Then, the system device 100 performs processing for data communication with the power transmission device 200 after activation.

  For example, the control unit 70 includes a host I / F 72, and the host I / F 72 is communicatively connected to the host I / F 18 on the power receiving unit side. The host I / F 72 is also communicatively connected to the host I / F 110 on the system device side. For example, the host I / F 72 of the control unit 70, the host I / F 18 on the power receiving unit side, and the host I / F 110 on the system device side are connected by a host I / F data line, a clock line, and various control lines.

  Then, after the host I / F 72 of the control unit 70 is activated by the power received by the power receiving unit 10, it performs initial communication processing for the host I / F 18 on the power receiving unit side instead of the host host I / F 110 on the system device side. .

  That is, normally, the host I / F 110 on the system device side transmits an initialization parameter to the host I / F 18 on the power receiving unit side. In contrast, in the present embodiment, the host I / F 72 of the control unit 70 transmits an initialization parameter to the host I / F 18 on the power receiving unit instead of the host I / F 110 on the system device side.

  The activation detection unit 74 of the control unit 70 detects whether or not the control unit 70 or the like can be activated by the power received by the power reception unit 10. The register unit 76 of the control unit 70 has various registers.

  Specifically, the register unit 76 includes a register that notifies the system device that the initial communication process has been performed on behalf of the system device 100. For example, when the control unit 70 performs initial communication processing instead of the system device 100, a flag for notifying that the initial communication processing has been performed is set on this register. Then, the system device 100 activated thereafter can confirm that the initial communication processing has been performed on behalf of itself by confirming this flag.

  In the present embodiment, the control unit 70 performs a process of transmitting an initialization parameter to the power receiving unit 10 as an initial communication process. Then, the power reception unit 10 that has received the initialization parameter receives a polling command from the power transmission device 200, and after the power reception unit 10 transmits a polling response to the power transmission device 200, the power reception unit 10 receives power between the power transmission device 200 and the system device 100. Data communication via the unit 10 is performed.

  In this case, the power supply management unit 20 performs control for accumulating charges in the capacitors C (C1 and C2) which are charge accumulation units during the above-described data communication period. Then, power based on the electric charge accumulated in the capacitor C (charge accumulating unit) is supplied to the system device 100 in a period after completion of power reception by the power receiving unit 10.

  In this way, after the power reception period indicated by G2 in FIG. 3 is completed, power is supplied to the system device 100 using the accumulated charge of the capacitor C, and display rewriting of the display unit 150 (EPD) indicated by G8 is performed. Processing can be realized.

  Next, the detailed operation of the present embodiment will be described with reference to the operation flowchart of FIG.

  First, the power transmission device 200 (reader / writer, etc.) starts power transmission by electromagnetic induction (S1), and shifts to a data communication waiting state (S2). Then, the power receiving unit 10 receives the power (S11), the power based on the received power is supplied, and the circuit device 90 is activated (S21). At this time, the system device 100 is not activated yet.

  The activated circuit device 90 executes an initial communication process in place of the system device 100 that has not yet been activated (S22). Specifically, the host I / F 72 of the control unit 70 transmits the initialization parameter to the host I / F 18 of the power receiving unit 10 instead of the host I / F 110 of the system device 100. For example, the host I / F data line, clock line, and control line are controlled to perform initialization parameter transmission processing.

  When receiving the initialization parameter by host communication via the host I / F 18 (S12), the power receiving unit 10 performs RF communication with the power transmission device 200 (S13). As a result, the state shifts to the RF response state. Specifically, the power transmission device 200 transmits a polling command, and the power receiving unit 10 (communication unit 16) that has received the polling command transmits a polling response to the power transmission device 200. The RF communication in this case is realized by electromagnetic induction using the coils L1 and L2. For example, transmission of information from the power transmission device 200 to the power reception unit 10 is realized by amplitude modulation processing, and transmission of information from the power reception unit 10 to the power transmission device 200 is realized by load modulation processing.

  The power transmission device 200 checks whether the polling response has been returned from the power receiving unit 10 and determines whether the polling has been successful (S3). If the polling response has not been returned, the polling has failed. (S4). On the other hand, if a polling response is returned and it is determined that the system is compatible, it is determined that the polling has succeeded, and the power transmission period is extended as indicated by G2 and G6 in FIG. 3 (S5). Then, the state shifts to a data communication waiting state (S6).

  After performing the initial communication process, the circuit device 90 starts to supply power to the system device 100 (S23). Specifically, the power management unit 20 that has received power from the power receiving unit 10 supplies power to the system device 100 based on this power. As a result, the hardware of the system device 100 is activated (S31), and subsequently, software (firmware) operating on the hardware is activated (S32). Then, display data communication processing starts (S33). Specifically, host communication of display data is performed between the host I / F 110 of the system device 100 and the host I / F 18 of the power receiving unit 10, and the power receiving unit 10 (communication unit 16) and the power transmission apparatus 200 are connected. Between the display data, RF communication (communication by electromagnetic induction using a coil) is performed (S14, S7).

  At this time, the circuit device 90 according to the present embodiment starts a charge accumulation operation to capacitors C (C1 and C2 to be described later) that are charge accumulation units (S24). That is, charge accumulation for the capacitor C is performed during the data communication period (S25). Then, when the charge accumulation in the capacitor C is completed (S26), the circuit device 90 notifies the end of the storage (S27). Based on this notification, the system device 100 determines that the power storage has ended (S34), and starts the display rewriting process of the display unit 150 (S35). That is, the display rewriting process of the display unit 150 is executed based on the display data received by data communication.

  Further, the end of power storage is notified to the power reception unit 10 and the power transmission device 200 through host communication and RF communication (S15, S8). Then, the power transmission device 200 notifies the user that power storage has been completed using a display device such as an LED, a speaker, or the like (S9), and stops power transmission (S10).

  When the storage of the capacitor C is completed, the circuit device 90 supplies power to the system device 100 using the stored power (S28). That is, at this time, the power transmission by the power transmission device 200 is stopped, and the power reception period of the power reception unit 10 ends. Therefore, the circuit device 90 supplies power to the system device 100 based on the electric charge accumulated in the capacitor C. Then, the system device 100 operates based on the power supplied by the capacitor C, and executes the display rewriting process of the display unit 150 (S36). Then, when the display rewriting process using the charge stored in the capacitor C is successfully completed (S37), the process is normally completed (S38). Then, the power supply based on the accumulated charge of the capacitor C is also terminated (S29).

  As described above, in this embodiment, after the power receiving unit 10 is activated by the power received (S11, S21), the control unit 70 of the circuit device 90 performs the initial communication process (S22) instead of the system device 100. . Specifically, the control unit 70 performs initial communication processing on behalf of the system device 100 before the system device 100 that receives power supply from the power management unit 20 is activated (S31). Then, after the control unit 70 performs the initial communication process (S22), the power management unit 20 supplies power to the system device 100 based on the power received by the power receiving unit 10 (S23). As a result, the system device 100 is activated (S31, S32), and display data communication processing (S33) is performed.

  In this way, after the power is turned on, the control unit 70 can start the initial communication process even if the system device 100 is not activated. Therefore, the entire system can be shifted to the next stage without waiting for the system device 100 to be activated. Thereby, for example, in the IC card system as shown in FIG. 2, it is possible to shorten the time required for card detection. Further, the processing of the system device 100 can be reduced, the processing of the entire system is reduced in weight, and the operation time can be shortened. In addition, since the time required for activation can be shortened, the polling period in FIG. 3 can be shortened to save power.

  For example, as a method of a comparative example of the present embodiment, a method in which the system device 100 performs initial communication processing during a polling period can be considered. In this method, the initial communication processing is executed after the software of the system device 100 is activated in S32 of FIG. Therefore, the start timing of the initial communication process of G5 in FIG. 3 is delayed, and it is necessary to ensure a long polling period. If the polling period becomes longer in this way, unnecessary power is consumed in the reader / writer or the like, and it becomes difficult to save power. If the polling period is short, the reader / writer cannot recognize the IC card 190 in FIG. As a result, the operation of polling and resetting is repeated, causing a problem that the target operation cannot be executed.

  In this regard, in the circuit device 90 of the present embodiment, initial communication is performed early instead of the system device 100. Therefore, it is possible to save power by shortening the polling period. Further, the situation in which the reader / writer cannot recognize the IC card 190 in FIG. 3 can be prevented. Therefore, it is possible to prevent a situation where the reset operation is repeated due to polling failure, and a stable operation can be realized.

  In the initial communication process of FIG. 4, the power receiving side starts processing and the power transmission side responds to it, but conversely, the power transmission side starts processing and the power receiving side responds to it. It may be processed. In this case, the initial communication process performed by the control unit 70 is a process in response to a command from the power transmission side.

  The host I / F 72 of FIG. 1 is connected to the host I / F 18 on the power receiving unit side and the host I / F 110 on the system device side. Then, after the host I / F 72 is activated by the power received by the power receiving unit 10, initial communication processing for the host I / F 18 on the power receiving unit side is performed instead of the host I / F 110 on the system device side.

  For example, the signal line of the host I / F includes a clock line, a data line, a data control line, a standby control line, and the like. The host I / F 18, the host I / F 72, and the host I / F 110 are commonly connected to these clock lines, data lines, data control lines, and standby control lines.

  When the power is turned on and the initial state is entered, the host I / F 72 changes the standby control line from the L level to the H level in place of the host I / F 110 on the system device side. As a result, the host I / F 18 on the power receiving unit side waits for the transfer of the initialization parameter. Then, the host I / F 72 transmits an initialization parameter to the host I / F 18 using the clock line and the data line. The initialization parameters can include various setting parameters such as data transfer settings and system code settings, maximum response time parameters, data format codes, user setting parameters, and the like.

  When receiving the initialization parameter, the power receiving unit 10 shifts to an RF response state in which a request from the reader / writer is received. In this RF response state, the reader / writer sends a polling command. When the power receiving unit 10 receives the polling command from the reader / writer (S13), the power receiving unit 10 checks whether the system code specified by the polling command matches the system code specified by the initialization parameter. In step S13, a polling response is transmitted to the reader / writer. When the reader / writer receives a polling response from the power receiving unit 10 within the polling period, the reader / writer determines that the polling is successful and extends the power transmission period (S5). Thereafter, when the system device 100 is activated (S31, S32), data communication between the reader / writer and the system device 100 is executed (S7, S14, S33). Specifically, the power receiving unit 10 receives display data from a reader / writer (power transmission device) by RF communication (for example, communication by amplitude modulation processing). The received display data is transmitted from the power receiving unit 10 to the system device 100 by host communication between the host I / F 18 and the host I / F 110. As described above, in this embodiment, the power receiving unit 10 that has received the initialization parameter receives the polling command from the reader / writer (power transmission device), and after the power receiving unit 10 transmits the polling response, the reader / writer and the system device 100. Data communication via the power receiving unit 10 is performed.

  The fact that the control unit 70 has performed the initial communication process on behalf of the system device 100 is notified to the system device 100 using the register of the register unit 76. For example, when the system device 100 is activated by system power supply (S23) (S31, S32), the system device 100 reads the register of the register unit 76 to determine whether the initial communication process has already been performed by the control unit 70 or not. Confirm. When it is confirmed that the initial communication process is performed, the system device 100 starts the data communication process of display data (S33).

  In addition, the power management unit 20 performs control to accumulate charges in the capacitor C (charge accumulation unit) during the data communication period (S7, S14, S33) (S24, S25, S26). Then, a power source based on the electric charge accumulated in the capacitor C is supplied to the system device 100 during a period after the end of power reception by the power receiving unit 10 (S28).

  In this way, charges can be accumulated in the capacitor C by effectively utilizing the communication period of data such as display data. Then, even after the power reception of the power receiving unit 10 is completed, it is possible to supply the power based on the charge accumulated in the capacitor C to the system device 100 to operate the system device 100.

  For example, the system device 100 performs display control processing of an EPD (electrophoretic display unit) that displays an image. The power supply management unit 20 performs control for accumulating charges necessary for rewriting at least one display of the EPD in the capacitor C (charge accumulation unit) (S25). The system device 100 is supplied with power based on the charge accumulated in the capacitor C during the power receiving period of the power receiving unit 10. Then, in the display rewriting period (S36) after power reception, EPD display rewriting processing is performed. In this way, even when the power reception period is short, the display device can be rewritten by operating the system device 100 with the power source using the charge accumulated in the capacitor C after the power reception is completed. Therefore, for example, a power supply method suitable for the IC card system as shown in FIG. 2 can be realized.

2. Starting Capacitor Next, a detailed configuration example of the power management unit 20 of the circuit device according to the present embodiment will be described with reference to FIG. In FIG. 5, the power management unit 20 includes a first accumulation control unit 30 and a power supply unit 50. Further, the power management unit 20 includes a second accumulation control unit 40.

  The first accumulation control unit 30 (first accumulation operation unit) receives power from the power receiving unit 10 that receives power by electromagnetic induction, and stores a capacitor C1 (first charge accumulation unit in a broad sense). Control (operation) for accumulating charges is performed. The second accumulation control unit 40 (second accumulation operation unit) receives electric power from the power receiving unit 10 and accumulates charges in the starting capacitor C2 (second charge accumulation unit in a broad sense). Perform control (operation).

  Specifically, the first accumulation control unit 30 is provided between the power input node NI from the power receiving unit 10 and the first accumulation node NA1. Then, the current and voltage for charging the main capacitor C1 for power storage are controlled to control charging to the capacitor C1.

  For example, it is assumed that the system device 100 performs display control processing of an electrophoretic display unit (EPD) that displays an image. In this case, the first accumulation control unit 30 performs control to accumulate charges necessary for display rewriting for at least one time in the electrophoretic display unit (nonvolatile display element) in the capacitor C1. By doing so, it is possible to rewrite the display unit of the system device 100 at least once after receiving power by electromagnetic dielectric. Thus, for example, when applied to a prepaid card or an IC card of electronic money, it is possible to display the usage amount, balance, etc. on the display unit of the IC card after the IC card is held over the terminal device.

  Here, the charge necessary for at least one display rewrite is, for example, a charge necessary for rewriting image data for one screen when performing display rewrite of an image for one screen after receiving power. Alternatively, when display rewriting of a part of one screen image is performed after power reception, the charge is necessary for rewriting part of the image data. The amount of these charges can be known in advance by design or actual measurement. Therefore, for example, the first accumulation control unit 30 may perform control for accumulating the charge corresponding to the worst case data in the design value or actual measurement value of the charge amount in the capacitor C1.

  On the other hand, the second accumulation control unit 40 is provided between the power input node NI from the power receiving unit 10 and the second accumulation node NA2. Then, the charging control to the capacitor C2 is performed by controlling the current and voltage for charging the starting sub capacitor C2.

  The power supply unit 50 supplies power based on electromagnetic induction power to the system device 100 and the control unit 70. For example, the power supply unit 50 supplies power to the system device 100 and the control unit 70 based on the charges stored in the capacitors C1 and C2 (first and second charge storage units). Specifically, a power supply voltage based on the voltages of the storage nodes NA1 and NA2 is output to the output node NQ of the power supply to the system device 100.

  In this case, the power supply unit 50 supplies power to the system device 100 after the power supply voltage obtained by the accumulated charge of the capacitor C2 (second charge storage unit) exceeds the operation lower limit voltage of the system device 100. It is desirable to do. Here, the operation lower limit voltage is a voltage for which the system device 100 is guaranteed to operate normally. For example, when the system device 100 is a microcomputer, the operation lower limit voltage is defined by the specification of the microcomputer. For example, when a power supply voltage lower than the operation lower limit voltage is supplied to the system device 100, there is a possibility that a malfunction such as a through current flows in a transistor constituting the system device 100 may occur. In this respect, such a problem can be prevented by preventing the power supply unit 50 from supplying power to the system device 100 until the operating lower limit voltage is exceeded.

  The system device 100 (power supply target device) is a device to which power is supplied by electromagnetic induction. The system device 100 performs, for example, display control processing of a display unit that displays an image. The system device 100 can be realized by a microcomputer with a built-in display controller, for example.

  In this embodiment, the capacitor C2 (second charge storage unit) includes a system startup charge storage unit having a charge storage capacity (capacitance) smaller than that of the storage capacitor C1 (first charge storage unit). It has become. As an example, the capacity of the capacitor C1 for storing electricity is several tens of μF to several hundreds of μF (for example, about 100 μF), and the capacity of the starting capacitor C2 is 1 μF or less (for example, about 0.1 μF). A capacitor such as a spar capacitor can be used as the capacitor C1 or the like serving as the storage element. Accordingly, since the power storage element can be configured to be thin, it can be easily built in an IC card or the like.

  One end of the capacitor C1 is connected to the storage node NA1, which is an output node of the first storage control unit 30, and the other end is connected to, for example, a GND node. One end of the capacitor C2 is connected to the storage node NA2 that is an output node of the second storage control unit 40, and the other end is connected to, for example, a GND node. Note that one end of a capacitor CC for stabilizing the potential is connected to the power input node NI.

  The power supply unit 50 supplies power based on the accumulated charge of the capacitor C2 (second charge accumulation unit) to the system device 100 and the control unit 70 when the system is started after the power reception unit 10 starts receiving power. That is, at the time of system startup, power based on the stored charge of the small-capacitance capacitor C2 for system startup (power supply voltage based on the voltage of the node NA2) is supplied to the system device 100 and the control unit 70.

  On the other hand, the power supply unit 50 supplies power based on the accumulated charge of the capacitor C1 (first charge accumulation unit) to the system device 100 and the control unit 70 in a period after the end of power reception by the power reception unit 10. . That is, in a period after the end of power reception when the system is activated and the capacitor is sufficiently charged, a power supply (power supply voltage based on the voltage of the node NA1) based on the accumulated charge of the large-capacity capacitor C1 for power storage is supplied to the system device. 100 and the controller 70.

  Note that the power supplied to the system device 100 and the control unit 70 in the period after the end of power reception is preferably a power based on the accumulated charges of both the capacitors C1 and C2. Further, it is sufficient that the power source based on the accumulated charge of the capacitor C2 is supplied to the system device 100 and the control unit 70 at the time of system start-up (first half of the power receiving period) during the power receiving period. A power source based on the accumulated charge of C <b> 1 may be supplied to the system device 100 and the control unit 70.

  In the circuit device according to the present embodiment shown in FIG. 5 described above, since the small-capacitance capacitor C2 for activation is charged in a short time after power reception by the power reception unit 10, the system device 100 and the control unit 70 are promptly charged. It is possible to start up the system by supplying a power supply voltage to. After that, a capacitor C1 having a larger capacity than that of the capacitor C2 is charged, and power is supplied to the system device 100 and the control unit 70 based on the charge charged in the capacitor C1 even after the end of the power receiving period. Can be operated.

  For example, when the circuit device according to the present embodiment is applied to a non-contact IC card, it is necessary to communicate with the terminal device in a short time to store electricity. However, the stored capacitor has a large capacity, and the rising of the charging voltage is slow, and there is a problem that communication cannot be started without releasing the reset of the system (system device).

  In this regard, in this embodiment, as shown in FIG. 5, in addition to the large-capacity capacitor C1 for power storage, a small-capacitance capacitor C2 for activation is provided. As a result, immediately after the start of power reception, the system device 100 and the control unit 70 can be operated with the charging voltage of the capacitor C2 to perform communication or the like. Accordingly, the system can be started up without depending on the capacity of the capacitor C1 for power storage, and the power storage and communication time can be shortened by starting up the communication system at an early stage.

  For example, an EPD that is a non-volatile display element is a display device suitable for the display unit 150 of the IC card 190 as shown in FIG.

  However, EPD has a problem that it takes a long time (for example, 1 second) to rewrite display information as compared with a liquid crystal display device. Therefore, as shown in FIG. 2, it is difficult to receive power and rewrite the display of the EPD by touch & go operation of holding the IC card 190 over the terminal device 202. .

  For example, in the method of the comparative example of FIG. 6A, the length T1 of the power reception period TR by electromagnetic induction is lengthened, and data from the terminal device 202 (reader / writer) in the first half of the power reception period TR as indicated by A1. Receive. Then, as shown by A2, the display rewriting of the EPD is performed in the display rewriting period TC in the latter half of the power receiving period TR. In this case, the length T2 of the display rewriting period TC is shorter than the length T1 of the power reception period TR.

  However, in the method of the comparative example of FIG. 6A, since the length T1 of the power receiving period TR becomes long, the touch & go operation (for example, an operation having a length of about 0.1 second) as shown in FIG. ) Cannot be realized.

  Therefore, in this embodiment, as shown in FIG. 6B, the length T1 of the power reception period TR is shortened. Then, data reception from the terminal device 202 is performed during the power receiving period TR as shown in A3, and display rewriting of the EPD is performed in the subsequent display rewriting period TC as shown in A4. In this case, when the length of the power receiving period TR is T1 and the length of the display rewriting period TC is T2, the relationship of T2> T1 is established.

  In this way, by shortening the length T1 of the power reception period TR, the IC card 190 can operate while receiving power by a touch & go operation as shown in FIG. In addition, by increasing the length T2 of the display rewriting period TC, the display information can be rewritten even when EPD is used as the display unit 150. That is, EPD requires a long time (1 second) to rewrite display information as compared with a liquid crystal display device. However, when T2 is long, at least one EPD display can be rewritten.

  In this case, if the length T1 of the power reception period TR is short, there is a possibility that sufficient electric charge necessary for EPD display rewriting cannot be accumulated.

  Therefore, in FIG. 5, a large-capacity capacitor is provided as the capacitor C1 for power storage. For example, by using a capacitor such as a spar capacitor as the capacitor C1, it is possible to accumulate sufficient electric charge necessary for display rewriting of the EPD.

  Specifically, the first accumulation control unit 30 performs control for accumulating charges necessary for at least one display rewriting of the EPD (electrophoretic display unit) in the capacitor C1 (charge accumulation unit).

  The system device 100 is supplied with power based on the charge stored in the capacitor C1 (charge storage unit) in the power reception period TR of the power reception unit 10, and performs display rewrite processing of the EPD in the display rewrite period TC after power reception. . For example, an EPD display rewriting process is performed based on data received from the terminal device 202 in the power reception period TR. In this case, as described above, a relationship of T2> T1 is established between the length T1 of the power reception period TR and the length T2 of the display rewriting period TC.

  That is, in this embodiment, as shown in FIG. 6B, charges are accumulated in the large-capacity storage capacitor C1 in the short power receiving period TR, and the display information rewriting process of the EPD is performed in the subsequent long display rewriting period TC. Do.

  In this way, it becomes possible to incorporate an EPD that can hold display information in a non-powered state with respect to an IC card that requires touch & go operation, and an IC card that can display various types of information by EPD. Can be realized.

  In this case, if the power reception period TR is shortened as shown in FIG. 6B, it becomes difficult to operate the system device 100 over the subsequent long display rewrite period TC.

  In this regard, in the present embodiment, a large-capacity storage capacitor C1 is provided, and the charging control in the first accumulation control unit 30 is devised, so that a long display rewriting period even in a short power receiving period TR. It has been successful in accumulating enough charge to operate the system device 100 over TC. In particular, by limiting the amount of charge accumulated in the capacitor C1 for power storage to the amount of charge required for one display rewriting of EPD, for example, even if the power receiving period TR is shortened, the system is extended over a long display rewriting period TC. It becomes possible to operate the device 100 and rewrite the display of the EPD.

  However, when the capacitor C1 for power storage has a large capacity as described above, there is a problem that the power supply voltage supplied to the system device 100 does not rise easily and the system cannot be started up at an early stage.

  Therefore, in the present embodiment, a startup capacitor C2 is provided separately from the storage capacitor C1. As shown in B1 and B2 of FIG. 7A, these capacitors C1 and C2 are charged via the first and second accumulation control units 30 and 40 based on the output voltage from the power receiving unit 10. The

  Then, as indicated by B <b> 3 in FIG. 7A, when the system is started after the start of power reception by the power receiving unit 10, power based on the stored charge of the startup capacitor C <b> 2 is supplied to the system device 100. That is, since the capacitance of the start-up capacitor C2 is small, the voltage of the charge storage node NA2 of C2 rises quickly, and this voltage is supplied to the system device 100 as a power supply voltage as indicated by B3.

  On the other hand, as shown in FIG. 7B, in the period after the end of power reception by the power receiving unit 10, power based on the accumulated charge of the capacitor C1 for power storage is supplied to the system device 100. That is, since the capacitor C1 for power storage is large, the rise of the voltage at the charge storage node NA1 of C1 is slow. However, when time elapses after the start of power reception, this voltage exceeds the operating lower limit voltage of the system device 100, and can be supplied to the system device 100 as a power supply voltage as indicated by B4.

  By doing so, it becomes possible to operate the system device 100 by turning on the system power at an early stage as indicated by A5 in FIG. As a result, the data reception process shown in A3 can be completed at an early stage, and a short power reception period for realizing a touch-and-go operation can be dealt with.

  That is, in order to realize the touch & go operation, it is necessary to complete data reception between the IC card 190 and the terminal device 202 during a short power reception period. However, if the large-capacity capacitor C1 is used, the rise of the power supply voltage is delayed, and if the rise of the system is also delayed, the start of data reception is delayed only by that amount, and the system device 100 is received during a short power reception period. Will not be able to complete the data reception process.

  In this regard, in the present embodiment, the system device 100 starts up and operates at an early stage by the power source based on the small-capacitance start-up capacitor C2, so that the system device 100 completes the data reception process even in a short power reception period. It becomes possible to respond to the touch & go operation of the IC card 190. As described above, the power supply method according to the present embodiment is a method suitable for a non-contact IC card or the like that includes an EPD display unit and requires a touch & go operation.

  Further, by providing the start-up capacitor C2 as shown in FIG. 5, it is possible to start up the power supplied to the control unit 70 at an early stage. For example, when the voltage of the node NA2 rises early, power based on the voltage of the node NA2 can be supplied to the control unit 70, and the control unit 70 can be operated early. Accordingly, the initial communication process (S22) of FIG. 4 is performed at an early stage, and a response within the polling period can be promptly performed.

  That is, if only the large-capacity capacitor C1 is provided, the rise of the voltage at the node NA1 is delayed, so that the power supply to the controller 70 may be delayed. In this regard, if a small-capacitance start-up capacitor C2 is provided as shown in FIG. 5, the power supply based on the voltage at the node NA2 is supplied to the control unit 70, so that the power supply of the control unit 70 can be started up early. Thus, the initial communication process can be executed early.

3. Detailed Configuration Example of Circuit Device Next, a detailed configuration example of the circuit device of the present embodiment will be described. FIG. 8 is a detailed first configuration example of the circuit device.

  In FIG. 8, the first accumulation control unit 30 in FIG. 5 is realized by the power storage regulator 32, and the second accumulation control unit 40 is realized by the activation regulator 42.

  The power storage regulator 32 receives the voltage VIN from the rectifier circuit 12 constituting the power reception unit 10 and outputs the voltage VA1 after voltage adjustment to the storage node NA1 through the backflow prevention diode I3. For example, the constant voltage VA1 is output by voltage adjustment. Specifically, for example, a maximum voltage of about 15 V is stepped down to a constant voltage VA1 of, for example, about 4.5 V by the regulator 32, and charge is stored in the capacitor C1 for power storage.

  The startup regulator 42 receives the voltage VIN from the rectifier circuit 12 and outputs the voltage VA2 after voltage adjustment to the storage node NA2. For example, the constant voltage VA2 is output by voltage adjustment. Specifically, for example, a maximum voltage of about 15 V is stepped down to a constant voltage VA2 of, for example, about 4.5 V by the regulator 42, and charge is stored in the starting capacitor C2.

  Note that the configuration of the first and second storage control units 30 and 40 is not limited to the regulators 32 and 42 that perform voltage adjustment as shown in FIG. 8, and for example, monitors the voltages of the storage nodes NA1 and NA2 to adjust the current. A circuit that performs the above may be used.

  In FIG. 8, the power supply unit 50 includes first and second diodes DI1 and DI2. Here, DI1 is a diode provided between the storage node NA1 of the power storage regulator 32 (first charge storage unit 30) and the connection node NC, and having a forward direction from the storage node NA1 to the connection node NC. It is. DI2 is a diode provided between the storage node NA2 of the activation regulator 42 (second charge storage unit 40) and the connection node NC and having a forward direction from the storage node NA2 to the connection node NC. It is. The power supply unit 50 supplies power to the system device 100 and the control unit 70 based on the voltage of the connection node NC.

  By configuring the power supply unit 50 with such diodes DI1 and DI2, it is possible to prevent backflow of current from the connection node NC to the storage nodes NA1 and NA2, and to supply the voltages VA1 and VA2 of the storage nodes NA1 and NA2 to the power supply. The voltage VC can be output to the connection node NC.

  FIG. 9A is a voltage waveform diagram for explaining the operation of the circuit device of FIG.

  When power reception is started and the voltage VIN from the power receiving unit 10 is supplied, the capacity VA2 of the capacitor C2 for activation is small, so that the voltage VA2 of the storage node NA2 of the capacitor C2 rises early as indicated by D1. As will be described in detail later, when the threshold voltage VTH corresponding to the operation lower limit voltage of the system device 100 is exceeded as indicated by D2, the voltage corresponding to the voltage VA2 is supplied to the system device 100 as the power supply voltage VC. Is done. Specifically, a voltage dropped from VA2 by the amount corresponding to the forward voltage of diode DI1 is supplied as VC.

  On the other hand, since the capacity of the storage capacitor C1 is large, the voltage VA1 of the storage node NA1 of the capacitor C1 gradually rises as indicated by D3. When the voltage VA1 rises, a voltage corresponding to the voltage VA1 is supplied to the system device 100 as the power supply voltage VC. Specifically, a voltage dropped from VA1 by the amount corresponding to the forward voltage of diode DI1 is supplied as VC.

  When the power reception period ends after the start of power reception, the charges of the capacitors C1 and C2 are discharged, so that the power supply voltage VC gradually decreases as indicated by D4. In this case, since the capacitance of the capacitor C1 is sufficiently large in this embodiment, a display rewrite period of a long time (for example, 1 second) is set as indicated by A4 in FIG. 6B or D5 in FIG. 9A. It becomes possible to secure.

  FIG. 9B is a diagram showing the relationship between the accumulated current and the discharge current. For example, during the power reception period, charges are accumulated in the capacitor as indicated by E1. Further, as indicated by E2, electric charge is discharged from the capacitor for system startup or the like. In the display rewriting period, the charge is discharged from the capacitor as indicated by E3, and the EPD display rewriting process by the system device 100 is performed based on the discharged charge.

  The configuration of the circuit device according to the present embodiment is not limited to that shown in FIG. 8, and various modifications can be made. For example, FIG. 10 shows a detailed second configuration example of the circuit device.

  In the second configuration example of FIG. 10, switch transistor circuits SW1, SW2, and SW3 are provided in place of the diodes DI1, DI2, and DI3 of FIG.

  According to the second configuration example of FIG. 10, since there is no voltage drop due to the forward voltage of the diode, there is an advantage that the power supply efficiency can be improved only by that amount.

  On the other hand, the first configuration example of FIG. 8 has an advantage that the control signal for the switch operation is unnecessary because the voltage switch operation is realized by the diodes DI1 and DI2. For example, before the system is started, it is difficult to generate such a control signal. However, according to the first configuration example in FIG. 8, it is possible to cope with such a situation.

  FIG. 11 shows a detailed third configuration example of the circuit device. In FIG. 11, the power supply unit 50 further includes a switch circuit 52 and a voltage detection circuit 54.

  Here, the switch circuit 52 is provided between the connection node NC of the diodes DI 1 and DI 2 and the output node NQ of the power supply unit 50. The voltage detection circuit 54 detects the voltage VC at the connection node NC. Then, when the voltage detection circuit 50 detects that the voltage VC of the connection node NC exceeds a given threshold voltage VTH, the switch circuit 52 is turned on (conductive state), and is connected to the system device 100. Power is supplied to it. For example, as shown by D2 in FIG. 9A, when the threshold voltage VTH is exceeded, the voltage detection circuit 54 activates the signal SCT, whereby the switch circuit 52 is turned on, and the voltage VC becomes the power supply voltage VQ. It is supplied to the system device 100.

  In this way, for example, power control can be performed in which the power supply voltage VQ is supplied to the system device 100 after the operating lower limit voltage of the system device 100 is exceeded. As a result, it is possible to effectively prevent a situation in which a power supply voltage equal to or lower than the operation lower limit voltage is supplied to the system device 100, a through current or the like is generated, and the operation becomes unstable.

4). Next, a configuration example of the system device 100 will be described. FIG. 12 shows a detailed configuration example of the system device 100. The system device 100 includes a host I / F 110, a processing unit 120, a register unit 130, a waveform information memory 140, an image memory 142, and a work memory 144. The configuration of the system device 100 is not limited to the configuration shown in FIG. 12, and various modifications such as omitting some of the components or adding other components are possible. For example, the memories 140, 142, and 144 may be external memories.

  The host I / F 110 is an interface for transmitting / receiving information to / from a counterpart device (power transmission device, terminal device, charger) serving as a host. The host I / F 110 is connected to the host I / F 18 on the power receiving unit 10 side via the control unit 70 as shown in FIG. As a result, transmission / reception of information to / from the power transmission device 200 (partner device) becomes possible. Transmission / reception of this information can be realized by, for example, amplitude modulation processing (frequency modulation processing) or load modulation processing using the coils L1, L2.

  The processing unit 120 performs display control processing of the display unit 150 and various control processes of the system. The processing unit 120 can be realized by a processor, a gate array circuit, or the like, for example.

  The display unit 150 whose display is controlled by the processing unit 120 includes a display panel 152 (electro-optical panel) and a driver circuit 154 that is a circuit for driving the display panel 152. The driver circuit 154 drives data lines (segment electrodes) and scanning lines (common electrodes) of the display panel 152. The display panel 152 is realized by a display element such as an electrophoretic element.

The register unit 130 includes various registers such as a control register and a status register. The register unit 130 can be realized by a RAM such as an SRAM or a flip-flop circuit. The waveform information memory 140 stores waveform information, instruction code information, and the like for driving the EPD. The waveform information memory 140 can be realized by, for example, a nonvolatile memory (for example, a flash memory) that can rewrite / erase data.

  The image memory 142 (VRAM) stores, for example, image data for one screen displayed on the display panel 152. The work memory 144 is a memory serving as a work area for the processing unit 120 and the like. The image memory 142 and the work memory 144 can be realized by a RAM such as an SRAM.

  FIG. 13A illustrates a configuration example of the display panel 152. The display panel 152 includes an element substrate 300, a counter substrate 310, and an electrophoretic layer 320 provided between the element substrate 300 and the counter substrate 310. The electrophoretic layer 320 (electrophoretic sheet) includes a large number of microcapsules 322 having an electrophoretic substance. The microcapsule 322, for example, disperses positively charged black positively charged particles (electrophoretic substance) and negatively charged white negatively charged particles (electrophoretic substance) in a dispersion liquid. It is realized by enclosing in a simple capsule.

  The element substrate 300 is formed of glass or transparent resin. The element substrate 300 includes a plurality of data lines (segment electrodes), a plurality of scanning lines (common electrodes), and a plurality of pixel electrodes in which each pixel electrode is provided at the intersection of each data line and each scanning line. Is done. In addition, a plurality of switch elements are provided in which each switch element formed by a TFT (Thin Film Transistor) or the like is connected to each pixel electrode. A data driver for driving the data lines and a scanning driver for driving the scanning lines are also provided.

  A common electrode (transparent electrode) is formed on the counter substrate 310, and a common voltage VCOM (counter voltage) is supplied to the common electrode. Note that the electrophoretic sheet may be formed by forming a common electrode with a transparent conductive material on the transparent resin layer, and applying an adhesive or the like on the transparent resin layer to adhere the electrophoretic layer.

  In the display panel 152 in FIG. 13A, when an electric field is applied between the pixel electrode and the common electrode, positively charged particles (black) and negatively charged particles (white) sealed in the microcapsule 322 are Electrostatic force acts in the direction according to the positive and negative charge. For example, positively charged particles (black) move to the common electrode side on the pixel electrode having a higher potential than the common electrode, so that the pixel is displayed in black.

  Next, the waveform information stored in the waveform information memory 140 of FIG. 12 will be described. Here, waveform information of an EPD (electrophoretic display unit) will be described as an example.

  For example, in a liquid crystal display device, as indicated by F1 in FIG. 13B, when changing the gradation of a pixel from the first gradation to the second gradation, data on the data line (source line) is displayed. The voltage also changes in one frame period from the data voltage VG1 corresponding to the first gradation to the data voltage VG2 corresponding to the second gradation.

  On the other hand, in EPD, when the gray level of a pixel is changed from the first gray level to the second gray level, as shown by F2 in FIG. Change over time. For example, when changing from the first gradation close to white to the second gradation close to black, the display of white and black is repeated over a plurality of frames to change the gradation of the pixel to the final second level. Change the key. For example, in the waveform of FIG. 13C, the data voltage changes over a plurality of frames such that the data voltage is set to VA in the first three frames and is set to -VA in the next three frames. Note that the waveform has a different shape depending on the combination of the pixel gradation in the current display state and the pixel gradation in the next display state.

  The waveform information memory 140 stores waveform information as indicated by F2 in FIG. The processing unit 120 determines the driving voltage of the EPD in each frame based on the image data (gradation data of each pixel) stored in the image memory 142 and the waveform information stored in the waveform information memory 140. Then, display control processing of the EPD (display unit 150) is performed.

  As is clear from comparison of F1 in FIG. 13B and F2 in FIG. 13C, EPD requires a longer time to rewrite display information than a liquid crystal display device or the like. Therefore, there is a problem that it is necessary to increase the length T2 of the display rewriting period TC in FIG.

  In this regard, in the present embodiment, as described above, the large-capacity capacitor C1 for power storage is provided, and charges necessary for display rewriting for at least one EPD are stored in the capacitor C1 during the power reception period TR.

  Further, by providing a small-capacitance capacitor C2 for activation, the system is turned on early as indicated by A5 in FIG. 6B. As a result, the processing unit 120 in FIG. 12 receives data such as display information from the counterpart device (power transmission device, terminal device) that is the host via the host I / F 110, as indicated by A3.

  Then, in the display rewriting period TC after power reception, the processing unit 120 performs EPD display rewriting processing as indicated by A4 in FIG. That is, based on the display information received through the host I / F 110 and written in the image memory 142 and the waveform information stored in the waveform information memory 140, the waveform as shown by F2 in FIG. EPD display rewrite processing is performed on the form.

  Thus, even with an EPD having a long display rewriting period, display information can be rewritten based on the charge received in the short power receiving period TR. Therefore, for example, an EPD display unit 150 that can hold display information in a non-powered state can be incorporated into a non-contact IC card that requires a touch & go operation as shown in FIG. An unprecedented type of IC card can be realized.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, in the specification or the drawings, at least once, terms (capacitors, storage capacitors, and the like) that are described together with different terms (charge storage unit, first charge storage unit, second charge storage unit, etc.) having a broader meaning or the same meaning. Starting capacitor etc.) may be replaced by the different terminology anywhere in the specification or drawings. All combinations of the present embodiment and the modified examples are also included in the scope of the present invention. In addition, the configuration and operation of the circuit device and the electronic device, the communication processing method, the power supply method, the charge storage method, and the like are not limited to those described in this embodiment, and various modifications can be made.

L1 primary coil, L2 secondary coil, CA, CB, CC capacitor,
C capacitor, C1 storage capacitor, C2 start-up capacitor,
DI1, DI2, DI3 first, second and third diodes,
SW1-SW3 switch transistor circuit,
10 power receiving unit, 12 rectifier circuit, 16 communication unit, 18 host I / F,
20 power management unit, 30 first accumulation control unit, 32 power storage regulator,
40 second storage control unit, 42 regulator for startup, 50 power supply unit,
52 switch circuit, 54 voltage detection circuit, 70 control unit, 72 host I / F,
74 start-up detection unit, 76 register unit, 90 circuit device,
100 system device, 110 host I / F, 120 processing unit,
130 register section, 140 waveform information memory, 142 image memory,
144 Work memory, 150 display unit, 152 display panel,
154 Driver circuit, 190 IC card,
200 power transmission device, 202 terminal device, 210 display unit, 300 element substrate,
310 counter substrate, 320 electrophoretic layer, 322 microcapsule

Claims (16)

A power management unit that receives power from a power receiving unit that receives power from the power transmission device by electromagnetic induction, and supplies power to the system device;
A control unit that operates by the power received by the power receiving unit by electromagnetic induction and performs control processing;
Including
The controller is
A circuit device that performs initial communication processing with the power transmission device via the power receiving unit instead of the system device after being activated by the power received by the power receiving unit by electromagnetic induction. In claim 1,
The controller is
A circuit device that performs initial communication processing with the power transmission device via the power reception unit instead of the system device before the system device that receives power supply from the power management unit is activated. . In claim 2,
The power management unit
A circuit device that supplies power to the system device based on the power received by the power receiving unit after the control unit performs the initial communication process. In any one of Claims 1 thru | or 3,
The controller is
A power receiving unit-side host interface provided in the power receiving unit, and a system device-side host interface provided in the system device, including a host interface connected in communication,
The host interface is
An initial communication process for the power receiving unit side host interface is performed instead of the system device side host interface after the power receiving unit is activated by the received power. In any one of Claims 1 thru | or 4,
The controller is
A circuit device comprising: a register that notifies the system device that the initial communication processing has been performed on behalf of the system device. In any one of Claims 1 thru | or 5,
The controller is
As the initial communication process, a circuit device that performs a process of transmitting an initialization parameter to the power receiving unit. In claim 6,
The power reception unit that has received the initialization parameter receives a polling command from the power transmission device, and after the power reception unit transmits a polling response to the power transmission device, the power reception unit between the power transmission device and the system device. A circuit device characterized in that data communication is performed via the terminal. In claim 7,
The power management unit
In the data communication period, the charge storage unit is controlled to store charges, and the power source based on the charge stored in the charge storage unit is supplied to the system device in a period after the end of power reception by the power receiving unit A circuit device characterized by being supplied. In any one of Claims 1 thru | or 7,
The power management unit
A first accumulation control unit that receives electric power from the power reception unit and performs control for accumulating charges in the first charge accumulation unit;
A power supply unit that supplies power to the system device based on the charge accumulated in the first charge accumulation unit;
A circuit device comprising: In claim 9,
A second accumulation control unit that receives electric power from the power receiving unit and performs control to accumulate charges in the second charge accumulation unit;
The second charge accumulation unit is a system activation charge accumulation unit having a charge accumulation capacity smaller than that of the first charge accumulation unit,
The power supply unit
A circuit device comprising: a power supply based on a stored charge of the second charge storage unit to the system device and the control unit when the system is started after the start of power reception by the power receiving unit. In claim 10,
The power supply unit
A first diode provided between a first storage node and a connection node of the first charge storage unit, the forward direction being a direction from the first storage node to the connection node;
A second diode provided between the second storage node and the connection node of the second charge storage unit and having a forward direction from the second storage node to the connection node. ,
The power supply unit
A circuit device that supplies power to the system device and the control unit based on a voltage of the connection node. In any of claims 9 to 11,
The power supply unit
A circuit device, wherein power is supplied to the system device based on the accumulated charge of the first charge accumulation unit during a period after the end of power reception by the power reception unit. In any of claims 9 to 12,
The system device performs display control processing of an electrophoretic display unit that displays an image,
The first accumulation control unit
A circuit device characterized by performing control for accumulating charges necessary for display rewriting at least once in the electrophoretic display section in the first charge accumulating section. A circuit device according to any one of claims 1 to 13,
An electronic apparatus comprising the system device. In claim 14,
The system device is:
An electronic apparatus that performs display control processing of an electrophoretic display unit that displays an image. In claim 15,
The system device is:
An electronic apparatus comprising: a power source based on charges accumulated in a charge accumulation unit during a power reception period of the power reception unit;

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