JP2006323683A - Card device and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for displaying information within an IC card if necessary with low power consumption by deciding the status of power of a non contact IC card which can stably supply power by way of electromagnetic induction with radio waves. <P>SOLUTION: The IC card device comprises a detecting means for detecting whether the power obtained through an antenna coil has voltage beyond the level for activating the IC card, a charging circuit for charging surplus power to a battery when the supplied power has the voltage beyond the level for activating the IC card, a means for firstly operating communication by the power from the battery when the supplied power has the voltage below the level for activating the IC card depending on the result of the detecting means and a means for displaying the information within the IC card on a display unit after completing the communication, makes the IC card operate communication with the supplied power when the supplied power has the voltage beyond the level for activating the IC card, and has a switching means for charging the surplus power to the battery with the charging circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a card device suitable for a non-contact IC card and a control method thereof.

  An IC card equipped with an IC module has been rapidly spreading in recent years because it can realize much higher security than a magnetic card. In particular, an electronic money system using an IC card has recently attracted attention, and it is possible to make an ATM terminal device (hereinafter referred to as an ATM terminal) cashless. The spread of IC cards is expected in that it eliminates the need for cash withdrawal. The IC cards that are currently popular are contact IC cards in which the IC module is exposed as a contact point, but non-contact IC cards that use data transmission by electromagnetic induction via radio waves are also gradually spreading. It's getting on. Since the IC module is not exposed, the non-contact type IC card has an advantage of operating with high reliability even in a dusty environment.

  However, in order to know electronic information from the data in the memory, it is necessary to read the contents of the IC card once from a reading device such as a reader / writer and display it on a display or output it to paper. In order to solve such problems, it is considered that a rewrite layer capable of rewriting an image is provided on the surface of an IC card. On this rewrite layer, desired data can be displayed as visible information on the card surface, and the display data can be rewritten as many times as necessary. Such an IC card is very convenient because necessary data in the IC card such as display of an expiration date and available balance can be displayed as visible information. However, the above invention requires a dedicated external writing device in order to form display data using the rewrite layer. In particular, since the rewritable layer of the present invention uses a heat-sensitive recording layer, it is necessary to provide a heat insulating layer or the like in order to prevent adverse effects of heat on ICs and wirings mounted in a card at a high density.

  On the other hand, the idea of providing a liquid crystal display device, which is a variable display medium, on the surface of an IC card has also been proposed. Since it is necessary to provide a plate or the like, it is difficult to make the display device thin enough to be mounted on an IC card. The physical size of the IC card is determined by the ISO standard. According to “ISO 7816-1,” the external dimensions are 85.47 to 85.72 mm in length, 53.92 to 54.03 mm in width, and 0 in thickness. .68 to 0.84 mm.

  Further, since the liquid crystal display device generally uses a glass material for the protective layer as described above, it is weak to bend, and from this point, it is not suitable for use in an IC card. IC chips mounted on IC cards are also vulnerable to bending, but mounting on a position outside the two center lines that intersect perpendicularly on the surface of the card makes it difficult for force to be applied to the IC chip even when the card is bent It has been devised. In this way, the parts to be mounted on the card are required to be devised so that durability and force are not applied, but the card surface has characters such as contact terminals and emboss formation, so it is not necessarily affected by bending It is not possible to mount a liquid crystal display device.

  Further, since liquid crystal display devices require continuous power and image signal supply for image display, information cannot be displayed if they are separated from a reader / writer or the like that supplies them. If an image is displayed by the card alone, a large capacity power supply (battery) must be provided in the card.

  Therefore, a technique using a ferroelectric liquid crystal display panel having a non-volatile property of display is disclosed in Japanese Patent Application Laid-Open No. 11-353438. According to this technique, power is required only when switching the display, so that it is not necessary to provide a power source in the card.

  However, although the conventional technique described in Patent Document 1 can achieve the intended purpose, there is a possibility that the operation may not be stable when the external power supply is not sufficient.

JP-A-11-353438

  Therefore, an object of the present invention is to provide a card device capable of performing a stable operation even when electric power supplied from the outside is not sufficient, and a control method therefor.

  As a result of intensive studies to solve the above problems, the present inventor has come up with various aspects of the invention described below.

  The card device according to the present invention includes an integrated circuit, an antenna coil connected to the integrated circuit, a power storage means for supplying power to the storage circuit, and a voltage of supplied power supplied from the outside via the antenna coil. And the integrated circuit communicates with the outside via the antenna coil using the supplied power when the voltage detected by the voltage detection means is equal to or higher than a predetermined voltage. And charging the power storage means surplus after the communication, and when the voltage detected by the voltage detection means is less than a predetermined voltage, using the power charged in the power storage means via the antenna coil And communicating with the outside.

  The card device control method according to the present invention includes an integrated circuit, an antenna coil connected to the integrated circuit, power storage means for supplying power to the storage circuit, and supply supplied from the outside via the antenna coil. And a voltage detecting means for detecting a voltage of power, wherein the antenna coil is controlled using the supplied power when the voltage detected by the voltage detecting means is equal to or higher than a predetermined voltage. And charging the power storage means with the surplus power after the communication, and if the voltage detected by the voltage detection means is less than a predetermined voltage, the power storage means is charged. And communicating with the outside through the antenna coil using the electric power.

  The program according to the present invention includes an integrated circuit including a computer, an antenna coil connected to the integrated circuit, power storage means for supplying power to the storage circuit, and supply power supplied from the outside via the antenna coil. A voltage detecting means for detecting the voltage of the card device, wherein the computer controls the operation of the card device, and when the voltage detected by the voltage detecting means is equal to or higher than a predetermined voltage, the supplied power Using the antenna coil to communicate with the outside, charging the power storage means after the communication surplus power, and when the voltage detected by the voltage detection means is less than a predetermined voltage, And a procedure for performing communication with the outside via the antenna coil by using electric power charged in the power storage means. To.

  According to the present invention, with respect to the power system, the voltage value of the power received by the antenna coil is detected, and the power supply source is switched between the outside or the storage means according to the detection result. Even if the power is not stable and sufficient power is not supplied, stable power can be used since stable power from the power storage means is used. In addition, in a state where sufficient power is supplied from the outside, excess power is charged in the power storage means, so that the power stored in the power storage means can be appropriately retained, and waste of power can be suppressed. it can.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a circuit configuration of a non-contact type IC card according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing an internal structure of the non-contact type IC card.

  In FIG. 2, 1 is a non-contact type IC card. The non-contact type IC card 1 includes a top cover sheet 101, a core sheet 103 having an antenna coil 102, a polymer lithium secondary battery 104, an IC module 105, and A lower cover sheet 106 is provided. The core sheet 103 is a sheet-like substrate for using the antenna coil 102 as a magnetic coupling coil, and has an opening (or recess) 108 on the inside. Then, a secondary battery 104 having flexibility, for example, a polymer lithium secondary battery is fitted into the opening (or recess) 108, and the upper cover sheet 101 or the lower cover sheet 106 made of an insulating material is used to move upward or downward. Is sandwiched between. Note that terminals 107 c and 107 d are provided at the end of the secondary battery 104, and the IC module 105 is connected to the secondary battery 104 via the terminals 107 c and 107 d. That is, the non-contact type IC card 1 includes a secondary battery (for example, a polymer lithium secondary battery) 104 having flexibility, an antenna coil 102, and an IC module 105.

  The top cover sheet 101 and the bottom cover sheet 106 can be made of any insulating material or conductive material with an insulating surface, but can be manufactured at low cost with excellent mass productivity. It is preferable to use an insulating plastic sheet. As the insulating plastic sheet, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), or the like can be used. Since the antenna coil 102 is a coil used for data transmission and power transmission using electromagnetic induction, examples of the material of the antenna coil 102 include aluminum, copper, silver, gold, tin, lead, indium, chromium, nickel, and the like. It is preferable to use a highly conductive metal material. In the form in which the conductive wire is wound, a wire in which a highly conductive metal material is covered with an insulator is preferable in order to avoid a short circuit. As long as it is a form in which a foil of a highly conductive metal material is attached to PET and etched, coating with an insulator is not necessarily required.

  As shown in FIG. 1, the IC module 105 includes an IC card controller 201, a protection circuit 202 for the secondary battery 104, a charge / discharge control circuit 203, a power supply circuit 204, and a display unit 205. The IC card controller 201 includes a CPU 210, a RAM 211, a ROM 212, an EEPROM 213, an input / output control circuit 214, and a display drive circuit 217, which are connected to each other via a bus 215. Further, a power supply circuit 204 under the control of the CPU 210 is also connected to the bus 215.

  The input / output control circuit 214 is a circuit that controls data transmission by receiving signals from the terminals 107a and 107b connected to the antenna coil 102 or sending signals to them. The terminals 107 a and 107 b are also power supply terminals and are also connected to the power supply circuit 204. In this embodiment, when the radio wave received by the antenna coil 102 is a modulated radio wave, the input / output control circuit 214 takes out the radio wave input from the terminals 107a and 107b as a signal, demodulates it, and the CPU 210 or the like. To the data processing circuit. On the other hand, when the radio wave received by the antenna coil 102 is in an unmodulated state in which only the radio wave (carrier) of the carrier wave is transmitted, or when the carrier wave is a radio wave with a strong output power particularly in a constant amplitude state, The power supply circuit 204 receives the radio waves input from the 107a and 107b, and the power supply circuit 204 extracts the electric power as power.

  The display drive circuit 217 is a circuit that drives the display unit 205, generates display data based on data on the RAM 211 (for example, data related to the balance), and performs control described later depending on the voltage status of the power supply circuit 204. In accordance with the flow (FIG. 5), the display unit 205 is driven to display the display data. The modulation method used when data is transmitted between the non-contact type IC card 1 and the IC card reader / writer 2 is, for example, any one of ASK, PSK, and FSK.

  The power supply circuit 204 supplies a tuning circuit 204a, a rectifier circuit 204b, a regulator 204c, a voltage detection circuit 204d for detecting the output voltage of the rectifier circuit 204b, and a power supply switching process in accordance with the detection signal of the output voltage detection circuit 204d. A power switching circuit 204e and an A / D conversion circuit (not shown) are provided. The supply power switching circuit 204e switches the supply power of the IC module 105 or the like to either the output of the regulator 204c or the output of the secondary battery 104 connected to the terminals 107c and 107d. The supply power switching circuit 204e also performs charge / discharge control of the secondary battery 104.

  An activation circuit 205 is connected to the tuning circuit 204a. A small amount of power is supplied from the secondary battery 104 to the activation circuit 205. The startup circuit 205 includes a high-frequency amplifier circuit that amplifies the signal from the tuning circuit 204a, a rectifier circuit, a power-on reset circuit that operates in response to the output of the rectifier circuit, and a power switch circuit (all not shown). The antenna card 102 is configured to activate the IC card controller 201 when it receives a current signal from a weak predetermined frequency radio wave. That is, when the antenna coil 102 receives a weak radio wave of a predetermined value or more, the power switch circuit is activated, the power-on reset circuit is activated, and the IC card controller 201 is activated to bring it into an operating state.

  The voltage detection circuit 204d detects the voltage of power supplied from the antenna coil 102 to the regulator 204c via the terminals 107a and 107b and the rectifier circuit 204b. Further, the supply power switching circuit 204e receives this detection signal from the voltage detection circuit 204d and monitors this voltage. Then, when the voltage detected by the output voltage detection circuit 204d is, for example, 4.0 V or more, the supply power switching circuit 204e applies a stabilized voltage from the regulator 204c, for example, power with a voltage of 3.6V. In addition to being sent to various circuits inside the module 105, part of the power supplied to the regulator 204 c is supplied as a charging current to the secondary battery 104 via the charge / discharge control circuit 203 and the protection circuit 202. Note that, regarding the charging of the secondary battery 104, the supply power switching circuit 204e may charge the capacitor 204f of the rectifier circuit 204e once with surplus power, and charge the surplus power to the secondary battery 104 after the operation. Good. However, in the latter case, since the capacitor 204f requires a large capacity, a capacitor externally attached to the non-contact type IC card 101 may be used.

  The supply power switching circuit 204e also supplies the stabilized power from the regulator 204c to the IC module 105 even when the voltage detected by the output voltage detection circuit 204d is, for example, less than 4.0V and 3.6V or more. Send to various internal circuits. However, in this case, surplus power is secured by charging the capacitor 204f of the rectifier circuit 204e, and the secondary battery 104 is not charged via the charge / discharge circuit 203 and the protection circuit 202.

  Further, the supply power switching circuit 204e receives power from the secondary battery 104 via the protection circuit 202 and the charge / discharge circuit 203 when the voltage detected by the output voltage detection circuit 204d is, for example, less than 3.6V. In response, power is supplied to various circuits inside the IC module 105, and the output of power from the regulator 204c is cut off.

  As described above, in this embodiment, the power supply circuit 204 selects whether to supply power from the secondary battery 104 or to supply power from the antenna coil 102 in accordance with the amount of power supplied by the radio wave (its voltage). .

  Therefore, even if the reception state of radio waves is weak, that is, a so-called weak electric field, various internal circuits can operate stably. The above switching control of the power supply switching circuit 204e is performed by the CPU 210 executing a predetermined program. As this program, a voltage monitoring program 213 a and a charge request processing program 213 b are stored in the EEPROM 213. The voltage monitoring program 213a is periodically executed by the CPU 210 by periodic interrupt processing. When the CPU 210 executes the voltage monitoring program 213a, the CPU 210 obtains the current voltage value of the rectifier circuit 204b detected by the output voltage detection circuit 204d as a digital value, and then sends a predetermined control signal to the supply power switching circuit 204e. Then, supply power switching control in the supply power switching circuit 204e is performed.

  FIG. 3 is a cross-sectional view showing an EPD display unit 205. The display unit 205 includes a TFT unit 22 provided with a thin film transistor as a switching element, an adhesive layer 23, a display medium 24 encapsulating toner, and a resin material 26. In the display medium 24, charged toner is contained between two plastic films. When the TFT section 22 applies an electric field to the display medium 24, the charged toner in the display medium 24 is electrostatically adsorbed on one of the electrodes according to the polarity and covers the surface. Here, if one electrode is black with a small area and the other is white with a large area, an image can be formed by generating contrast. As described above, the EPD display unit 205 forms an image by electrically changing the in-plane distribution of the toner. Note that after the image is formed, even if the power supply is cut off, the toner adsorbed on the electrode surface maintains its state, so the display image is non-volatile.

  As described above, the display unit 205 performs a display operation by forming a predetermined electric field on the display medium 24 and physically moving (migrating) the particles constituting the display medium 24. Therefore, even when the driving of the display driving circuit 217 is stopped, the moved (migrated) particles can maintain the state for a certain period, and as a result, the display content has a characteristic of being retained for a certain period. The period for holding the display content (hereinafter referred to as the display holding period) depends on the size and type of the particles constituting the display medium 24. For example, a display holding period of several days to several tens of days can be secured. It is. On the other hand, the time for driving the display driving circuit 217 to display once is about several tens of microseconds. For this reason, the display driving circuit 217 only needs to be driven for a short time, so that power consumption can be suppressed to a minute. For example, if the current required for display is 50 μA and the driving time is 0.1 msec, the required power is 0.5 mW.

  Here, the display medium 24 will be described. Various display media 24 can be selected and used. Here, four of them will be described. 4a to 4d are diagrams showing the mechanism of the display medium 24. FIG.

  FIG. 4 a is a schematic diagram showing an electrophoretic display 130. The binder 132 includes at least one capsule 134 filled with a plurality of particles 136 and a dye suspending fluid 138. The particles 136 are titania particles, for example. When a suitable polarity DC electric field is applied to the capsule 134, the particles 136 move to the visual plane of the display and scatter light. When the applied electric field is reversed, the particles 136 move to the back of the display and the visual surface of the display appears dark.

  FIG. 4 b is a schematic diagram showing another electrophoretic display 140. In the electrophoretic display 140, a first set of particles 142 and a second set of particles 144 are contained within a capsule 141. The first set of particles 142 and the second set of particles 144 have contrasting optical properties. For example, the first set of particles 142 and the second set of particles 144 can have different electrophoretic mobilities. Also, the first set of particles 142 and the second set of particles 144 may have colors that contrast with each other. For example, the first set of particles 142 can be white and the second set of particles 144 can be black. The capsule 141 further includes a substantially transparent fluid. In addition, electrodes 146 and 146 ′ are arranged with the capsule 141 interposed therebetween. The electrodes 146, 146 ′ are connected to a voltage source 48 and may provide an alternating current (AC) field or a direct current (DC) field to the capsule 141. When an electric field is applied to the capsule 141, the first set of particles 142 moves toward the electrode 146 ′, while the second set of particles 144 moves toward the electrode 146.

  FIG. 4 c is a schematic diagram showing the suspended particle display 150. Suspended particle display 150 includes acicular particles 152 in a permeable fluid 154. The particle 152 changes the direction in which the major axis is directed when an AC electric field is applied between the electrodes 156 and 156 ′. That is, when an AC electric field is applied, the particles 152 are oriented perpendicular to the display surface and the display appears transparent. On the other hand, when the AC electric field is removed, the particles 152 are randomly oriented and the display 150 appears opaque.

  FIG. 4d is a schematic diagram showing a display 160 including a plurality of heavy chromium spheres. The heavy chromium sphere 161 includes in the liquid medium 166 a positively charged hemisphere 162 of a first color and a negatively charged hemisphere 164 of a second color. When an electric field is applied to the sphere 161 through the pair of electrodes 168 and 168 ', the sphere 161 rotates to display one color of the two hemispheres 162,164.

  The electrophoretic displays shown in FIGS. 4a to 4d are examples, and other electrophoretic displays may be used. Further, a liquid crystal display device, a reflective liquid crystal display device, a transmissive liquid crystal display device, a transflective liquid crystal display device, a cholesteric liquid crystal display device, a dry toner display device, an organic EL display device, or the like may be used.

  Next, the charging and power supply operations of the non-contact type IC card configured as described above will be described. FIG. 5 is a flowchart showing operations of charging and power supply of the contactless IC card according to the embodiment of the present invention.

  First, when the non-contact type IC card 1 is brought close to an IC card reader or IC card reader / writer 2 (see FIG. 1) compatible with the non-contact type IC card, the antenna coil 102 of the non-contact type IC card 1 is contactless. The electromagnetic wave transmitted from the type IC card compatible reader (reader / writer 2) is received (step S101). At this time, a weak predetermined frequency wave, for example, a frequency of 13.56 MHz, is supplied to the antenna coil 102. When this is received by the antenna coil 102, when the tuning circuit 204a is tuned and the received radio wave level reaches a certain level, the activation circuit 205 operates to activate the IC module 105. As a result, the IC module 105 enters an operating state.

  In addition, a voltage is induced between the terminals of the antenna coil 102 by this reception, and the voltage is received by the rectifier circuit 204b in the power supply circuit 204 and rectified to obtain a predetermined voltage of power (step S102).

  Furthermore, the CPU 210 compares the voltage of the power rectified by the rectifier circuit 204b in step S102 with the IC card drivable voltage (eg, 3.6V) by executing the periodic voltage monitoring program 213a (step S103). .

  If the voltage of the power rectified by the rectifier circuit 204b is equal to or higher than the IC card drive voltage, the power from the antenna coil 102 is supplied to the supply power switching circuit 204e via the regulator 204c to the IC card controller 201. Supply (step S104). Furthermore, in particular, when the voltage of the power rectified by the rectifier circuit 204b is 4.0 V or more, as shown by a broken line, the process proceeds to step S112 and the charging process is performed at the same time. And it does not complete | finish as it is, but also transfers to step S106 from step S112 as further shown with a broken line.

  On the other hand, in step S103, if the voltage rectified by the rectifier circuit 204b is less than the IC card drivable voltage, the CPU 210 controls the supply power switching circuit 204e from the secondary battery 104 via the charge / discharge control circuit 203. Electric power is supplied (step S105). Although details will be described later, when the power supply from the secondary battery 104 is switched to, the CPU 120 monitors the voltage supplied from the secondary battery 104 based on the voltage monitoring program 213a. When the voltage is lower than a predetermined value, for example, when the voltage is 3.3 V or lower, a charging request signal 41 (see FIG. 6) is generated and the IC card reader / writer 2 (radio wave transmission side device) as shown by a broken line. The charging request process for requesting the generation of radio waves for power supply is entered.

  As described above, after obtaining power from the antenna coil 102 or power from the secondary battery 104 through step S104 or S105, the IC module 105 is activated and the IC card reader / writer via the antenna coil 102 is activated. 2 and signal processing are started (step S106).

  When the communication with the IC card reader / writer 2 and the signal processing are completed, the display contents backed up on the RAM 211 are changed, or the display limit time (display unit 205 (for example, electronic paper) is displayed after the display is performed. (Display limit)) is exceeded (step S107), and if the display needs to be changed or changed, the process proceeds to step S108. On the other hand, if neither display change nor update is required, the process proceeds to step S111. In determining whether update is necessary, for example, the date and time information displayed and executed from the IC card reader / writer 2 side in the RAM 211 is acquired and backed up, and the current time at which communication with the IC card reader / writer 2 side is performed. And the display elapsed time may be calculated.

  In step S108, it is determined whether or not the power supplied from the antenna coil 102 or the power supplied from the secondary battery 104 is at a level that can be displayed (for example, 0.5 mW or more) (step S108). If so, the process proceeds to step S109. In step S109, as a result of signal processing with the IC card reader / writer 2 side, display data is created by the display drive circuit 217 based on information stored in the RAM 211, for example, and sent to the display unit 205.

  On the other hand, if display is not possible, the process proceeds to step S110. In step S110, an abnormal code indicating insufficient power is notified to the IC card reader / writer 2 side. Although not shown in the figure, the IC card reader / writer 2 side that has received the power shortage abnormal code notifies the user that the card should be tapped again to secure the card power.

  When the data transmission process is completed, the CPU 210 controls the supply power switching circuit 204e to charge the secondary battery 104 with the surplus power stored in the capacitor 204f via the charge / discharge control circuit 203 (step S111). And S112). In this case, when the surplus power is less than the charging voltage, it is preferable to provide a booster circuit or the like to boost and charge.

  Next, an operation when the supply voltage from the secondary battery 104 becomes a predetermined value or less, for example, 3.3 V or less in step S103, that is, a charge request process will be described. FIG. 6 is a flowchart showing a charge request process by the voltage monitoring program 213a of the CPU 210.

  First, as described above, when the antenna coil 102 receives a weak predetermined frequency radio wave, for example, a radio wave with a frequency of 13.56 MHz (step S101 in FIG. 5), the tuning circuit 204a tunes the received radio wave. When the level reaches a certain level, the activation circuit 205 operates to activate the IC module 105 upon receiving power from the secondary battery 104. As a result, the IC module 105 enters an operating state. When the IC module 105 enters the operating state, in a normal state, the CPU 210 monitors the output voltage of the rectifier circuit 204b (step S102 in FIG. 5) using the output voltage detection circuit 204d. When the output voltage of the rectifier circuit 204b becomes less than 3.6 V (step S103 in FIG. 5), the voltage of the secondary battery 104 is monitored using the output voltage detection circuit 204d. That is, the CPU 210 periodically executes the voltage monitoring program 213a and compares the voltage between the terminals of the secondary battery 104 obtained by the output voltage detection circuit 204d with a preset threshold voltage to determine the remaining battery level. Detection is performed (step S201).

  Then, when the remaining amount of the secondary battery 104 decreases and becomes equal to or lower than the specified inter-terminal voltage (3.3 V or lower), the CPU 210 executes the charging request processing program 213b to connect the antenna coil 102 from the non-contact IC card 1 side. Then, the charging request signal 41 is transmitted to the IC card reader / writer 2 (step S202).

  The IC card reader / writer 2 side detects the charging request signal 41 (step S203), and sends the power carrier wave 42 to the non-contact type IC card 1 for a certain period (step S204). At this time, the waveform of the power carrier wave 42 is a waveform only during charging that does not depend on the content of data to be transmitted and received. Thereby, the non-contact IC card 1 side performs the charging process of the secondary battery 104 (step S205). Then, the IC card reader / writer 2 side stops the output operation of the power carrier wave after a preset time (step S206).

  Note that it is preferable to use a sine wave set at a specific frequency as the power carrier wave 42 because transmission loss is reduced and power can be efficiently taken in on the non-contact type IC card 1 side. . Further, as described above, the power carrier 42 is stopped from being sent from the IC card reader / writer 2 after a preset time has elapsed since the sending to the non-contact type IC card 1 was started. (Step S206) In this case, the predetermined period can be set to 10 seconds, for example.

  After the transmission of the power carrier 42 is stopped (step S206), the IC module 105 returns to the state of monitoring the voltage between the terminals of the secondary battery 104, and the processes of steps S201 to S206 are repeated. If it is determined in step S201 that is repeatedly performed that the secondary battery 104 is fully charged (step S207), the charging process is terminated without performing the process of sending the charge request signal 41. In addition, when the voltage from the regulator 204c can be used, including during reception of the power carrier wave 42, the power is supplied to the IC module 105 and the like.

  Next, the charging operation of the secondary battery 104 by the charge / discharge circuit 203 will be described. FIG. 7 is a flowchart illustrating an example of the charging operation of the secondary battery 104 by the charging / discharging circuit 203.

  Here, constant voltage charging is performed after first performing constant current charging. That is, when there is an instruction to start charging, first, constant current charging is started (step S401). The constant current charging is performed at a constant current value until the charging voltage becomes a specified voltage (step S402). Then, when the charging voltage reaches the specified voltage, it shifts to constant voltage charging. However, if the constant current charging is started and the elapsed charging time exceeds a predetermined time, it is determined that there is an abnormality in the battery, and the charging is terminated (step S403).

  Constant voltage charging is started in step S404, and constant voltage charging is performed at a constant voltage until the charging current reaches a specified voltage (step S405). Then, the process ends when the charging current reaches the specified current. As in the case of constant current charging, if constant voltage charging is started and the elapsed charging time exceeds the specified time, it is determined that there is an abnormality in the battery, and charging is terminated (step S406).

  Next, the power supply operation (discharge operation) of the secondary battery 104 by the charge / discharge circuit 203 will be described. FIG. 8 is a flowchart showing an example of the power supply operation (discharge operation) of the secondary battery 104 by the charge / discharge circuit 203.

  The charge / discharge circuit 203 causes the secondary battery 104 to start discharging to the load and monitors the discharge voltage (step S301). When the discharge voltage becomes equal to or higher than the specified voltage, the charge / discharge circuit 203 stops discharging to prevent overdischarge ( Step S303). Also, the discharge current is monitored (step S302), and the discharge is stopped even when the discharge current becomes equal to or higher than the specified current (step S303). After stopping the discharge, the discharge is interrupted until the discharge current or the discharge voltage falls within the specified value, and the power supply is temporarily stopped (step S304). When the value falls within the specified value, the process returns to step S301, and power supply (discharge) is resumed, as indicated by the broken line. The charging / discharging circuit 203 always monitors the discharge voltage and the discharge current during power supply (during discharge) (step S305).

  In this embodiment, the display unit 205 can effectively display the data content in the card even with low power. Further, since the display unit 205 is flexible and bendable, it can be handled in the same manner as a conventional paper IC card. Furthermore, since a lightweight and thin electrophoretic display is employed, a variable display medium can be formed on an IC card whose thickness is determined by a standard such as ISO. Furthermore, since the displayed image remains even after the supply of power or image signals is stopped, power consumption for image display can be reduced, and even when the card is separated from the reader / writer or the like. You can continue to display images on the card. Thus, if applied to a prepaid card, a point card, etc., the remaining amount and points stored in the card can be confirmed, and troubles due to erroneous operations or misunderstandings can be eliminated.

  Regarding the power system, the voltage value of the power received by the antenna coil 102 by radio waves is monitored, and when the voltage of the supplied power is less than a movable voltage value in the power supply by the radio waves, the secondary battery 104 (or capacitor). The IC card is operated by the power from the power source, and when the supplied power voltage is equal to or higher than the movable voltage value, the secondary battery 104 or the like is charged via the charge / discharge control circuit 203 by the surplus power during or after the operation. This allows the IC module to operate using stable power such as the secondary battery 104 without using unstable power due to radio waves when the voltage value is less than the movable voltage value in the unstable power supply via radio waves. Can do. Furthermore, since excess power is used for charging, power is not wasted. Moreover, even when the power received by the antenna coil 102 by radio waves is used, the excess power can be sent to the charging side, so even if the radio wave output is too strong, the IC module 105 side should use power with a stable voltage. Can do.

  Next, an example of dimensions and electrical characteristics of a non-contact type IC card having such a charge / discharge circuit will be described. In the non-contact type IC card 1 having outer dimensions of 54.0 mm in length, 85.6 mm in width, and 0.76 mm in thickness using PET, for example, the outer dimensions of the secondary battery (polymer lithium) 104 are 43. It is assumed that 0 mm, width 60.0 mm, and thickness 0.5 mm are used. The mass of the secondary battery 104 is 2.13 g, the voltage is 3.6 V, and the capacity is 22.4 mAh. In this non-contact type IC card 1, when data is transmitted using the antenna coil 102, if a current of 10 mA at maximum and an average current of 3 mA are passed, A current of 150 μA and an average of 35 μA can be passed. With these current values and the secondary battery capacity of 22.4 mAh, the secondary battery 104 can last about 160 days if it is only in standby after being fully charged. In addition, in the case where continuous data transmission is performed after the secondary battery 104 is sufficiently charged, approximately 2.2 hours are possible.

  As the secondary battery, a secondary battery other than the polymer lithium secondary battery may be used, and a capacitor for storing electric power may be used instead of the secondary battery.

  The embodiment of the present invention can be realized by, for example, a computer executing a program. Also, means for supplying a program to a computer, for example, a computer-readable recording medium such as a CD-ROM recording such a program, or a transmission medium such as the Internet for transmitting such a program is also applied as an embodiment of the present invention. Can do. The above program can also be applied as an embodiment of the present invention. The above program, recording medium, transmission medium, and program product are included in the scope of the present invention.

It is a block diagram which shows the circuit structure of the non-contact-type IC card which concerns on embodiment of this invention. It is a disassembled perspective view which shows the internal structure of the non-contact-type IC card which concerns on embodiment of this invention. FIG. 11 is a cross-sectional view showing an EPD display unit 205. 3 is a schematic diagram showing an electrophoretic display 130. FIG. It is a schematic diagram which shows the other electrophoretic display. 2 is a schematic diagram showing a suspended particle display 150. FIG. It is a schematic diagram which shows the display 160 containing a some heavy chromium sphere. It is a flowchart which shows the operation | movement of charge and power supply of the non-contact-type IC card which concerns on embodiment of this invention. It is a flowchart which shows the charge request | requirement process by the voltage monitoring program 213a of CPU210. 4 is a flowchart illustrating an example of a charging operation of the secondary battery 104 by the charging / discharging circuit 203. 5 is a flowchart showing an example of power supply operation (discharge operation) of the secondary battery 104 by the charge / discharge circuit 203.

Explanation of symbols

  1: non-contact type IC card, 205: display unit, 22: TFT unit, 24: display medium, 101: top cover sheet, 102: antenna coil, 103: core sheet, 104: secondary battery (polymer lithium secondary battery) ), 105: IC module, 106: bottom cover sheet, 107a, 107b, 107c, 107d: terminal, 108: opening, 201: IC card controller, 202: protection circuit, 203: charge / discharge control circuit, 204: power supply Circuit 204a: tuning circuit 204b: rectifier circuit 204c: regulator 204d: voltage detection circuit 204e: supply power switching circuit 205: display unit 210: CPU 211: RAM 212: ROM 213 EEPROM 214: Input / output control circuit, 215: Bus, 217: Display drive circuit

Claims (9)

An integrated circuit;
An antenna coil connected to the integrated circuit;
Power storage means for supplying power to the storage circuit;
Voltage detection means for detecting the voltage of power supplied from outside via the antenna coil;
Have
The integrated circuit comprises:
When the voltage detected by the voltage detection means is equal to or higher than a predetermined voltage, the power supply is used to communicate with the outside via the antenna coil, and the power storage means is charged with the surplus power after the communication,
When the voltage detected by the voltage detection means is less than a predetermined voltage, the card device performs communication with the outside via the antenna coil using the power charged in the power storage means. Storage means connected to the integrated circuit;
Display means for displaying information stored in the storage means;
Have
2. The card device according to claim 1, wherein the integrated circuit rewrites information stored in the storage unit in accordance with a result of the communication, and causes the display unit to display the rewritten information.   3. The card device according to claim 1, further comprising an activation circuit that activates the integrated circuit when receiving a current signal of a radio wave having a predetermined frequency via the antenna coil. Rectifying means for rectifying a current signal of power supplied from the antenna coil;
Charging means for charging the power storage means with surplus power obtained through the rectifier circuit either during or after operation of the integrated circuit;
4. The card device according to claim 1, comprising:   When the voltage detected by the voltage detection means is less than a predetermined voltage and the voltage of the electric power charged in the power storage means is equal to or lower than a second predetermined voltage lower than the predetermined voltage, the antenna coil 5. A power supply request signal for requesting supply of power necessary for charging the power storage means is transmitted to the other party supplying the power. 5. The card device described.   6. The card device according to claim 2, wherein the display means has a non-volatility that maintains a display state even after the electrical drive signal is cut off.   The display means is selected from the group consisting of a liquid crystal display device, a reflective liquid crystal display device, a transmissive liquid crystal display device, a transflective liquid crystal display device, a cholesteric liquid crystal display device, a dry toner display device, and an organic EL display device. The card device according to claim 2, wherein the card device is a seed. An integrated circuit;
An antenna coil connected to the integrated circuit;
Power storage means for supplying power to the storage circuit;
Voltage detection means for detecting the voltage of power supplied from outside via the antenna coil;
A method of controlling the operation of a card device comprising:
When the voltage detected by the voltage detection means is equal to or higher than a predetermined voltage, communicating with the outside via the antenna coil using the supplied power, and charging the power storage means with surplus power after the communication When,
When the voltage detected by the voltage detection means is less than a predetermined voltage, communicating with the outside via the antenna coil using the power charged in the power storage means;
A method for controlling a card device, comprising: An integrated circuit including a computer;
An antenna coil connected to the integrated circuit;
Power storage means for supplying power to the storage circuit;
Voltage detection means for detecting the voltage of power supplied from outside via the antenna coil;
A program for causing the computer to control the operation of the card device,
In the computer,
When the voltage detected by the voltage detection means is equal to or higher than a predetermined voltage, a procedure for communicating with the outside via the antenna coil using the supplied power and charging the power storage means with surplus power after the communication When,
When the voltage detected by the voltage detection means is less than a predetermined voltage, a procedure for communicating with the outside via the antenna coil using the power charged in the power storage means;
A program characterized by having executed.

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