JP2010182098A - Card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a card which emits light with power supplied by non-contact communication, allows falsehood determination using a light-emission state and facilitates visual confirmation of the light-emission state. <P>SOLUTION: The card includes an antenna 21 which receives an electromagnetic wave radiated from a power supply source and generates an electromotive force according to the strength of the electromagnetic wave; an organic EL device which emits light with brightness according to the supplied current; a drive voltage generating section 40 which generates a sufficient voltage for bringing the organic EL device to the light-emission state having predetermined brightness based on the electromotive force generated by the antenna 21; and a constant current circuit 43 which, only when the voltage generated by the drive voltage generating section 40 becomes not less than a predetermined value that is defined as a lower value with a margin than the voltage that brings the organic EL device to the light-emission state, supplies current according to the voltage to the organic EL device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a card that emits light by power supplied by non-contact communication, and more particularly to a technique for improving the visibility of a light emitting state.

  In recent years, with the progress of the information-oriented society, information is recorded on a card, and information management and settlement using the card are performed. Cards used for such information management and settlement include IC cards with built-in IC chips and magnetic cards on which information is written by magnetism, and information is written and read using a dedicated device. Is called.

  Further, in the IC card, a contact type IC card that performs writing and reading of information by contacting a dedicated device, and a non-contact type IC that can perform writing and reading of information only by being brought close to the dedicated device. There is a card. These IC cards are higher in security than magnetic cards, have a large amount of writable information, and can use a single card for multiple purposes. Therefore, the popularity of the IC card is increasing. . Among them, in the non-contact type IC card, when writing or reading information, it is not necessary to take out the card and insert it into a dedicated device, so that it is convenient for handling. Devices for reading information are rapidly spreading.

  In recent years, a non-contact type IC card having a light emitting function has been considered, which is disclosed in, for example, Patent Document 1. The non-contact type IC card disclosed in Patent Document 1 can display information written in a memory by causing an organic EL element to emit light when an electromotive force is generated due to proximity to a reader / writer. It is configured. Further, Patent Document 2 discloses a sheet that enables authenticity determination by incorporating a light emitting means. In this sheet, authenticity can be determined by causing the light emitting means to emit light when power is supplied from a terminal provided on the edge of the sheet.

  Therefore, by combining the above-described techniques, when an electromotive force is generated by approaching the reader / writer, it is possible to determine the authenticity by causing the light emitting element to emit light by the electromotive force.

JP 2008-217215 A JP 2004-78608 A

  However, in the conventional technology as described above, even if the authenticity determination is performed using the light emission state, the light emitting elements of all cards emit light as long as the card generates an electromotive force by approaching the reader / writer. Therefore, it is difficult to say that authenticity determination can be performed. Further, depending on the operation of bringing the reader / writer close, the light emission state may be instantaneous, in which case there is a possibility that the light emission state cannot be confirmed and the authenticity determination cannot be performed. In particular, in an organic EL element, in order to make the brightness constant, a constant current circuit is used to set a current supplied to the organic EL element to a value at which the organic EL element has a light emission state having a predetermined brightness. In this case, since the brightness of the organic EL element is constant, as described above, it is extremely difficult to confirm the light emission state when the light emission state is instantaneous. There is a problem that.

  The present invention has been made in view of the problems of the conventional techniques as described above, and in a card that emits light by power supplied by non-contact communication, authenticity determination can be performed using a light emission state. An object of the present invention is to provide a card that can make the light emission state easily visible.

In order to achieve the above object, the present invention provides:
An antenna that receives an electromagnetic wave irradiated from a power supply source and generates an electromotive force according to the intensity of the electromagnetic wave;
An organic EL element that emits light with brightness according to the supplied current;
Driving voltage generating means for generating a voltage sufficient for the organic EL element to be in a light emitting state having a predetermined brightness based on the electromotive force generated in the antenna;
Only when the voltage generated by the drive voltage generating means is equal to or higher than a predetermined value that has a margin and a lower value than the voltage value at which the organic EL element is in the light emitting state, the voltage is determined according to the voltage. Current supply means for supplying the current to the organic EL element.

  In the present invention configured as described above, when the electromagnetic wave irradiated from the power supply source is received by the antenna and an electromotive force corresponding to the intensity of the electromagnetic wave received by the antenna is generated, the drive voltage generating means In FIG. 5, a sufficient voltage is generated based on the electromotive force generated in the antenna so that the organic EL element is in a light emitting state having a predetermined brightness and is supplied to the current supply means. In the current supply means, a current corresponding to the voltage supplied from the drive voltage generation means is supplied to the organic EL element, and the organic EL element emits light with a brightness corresponding to the current supplied from the current supply means. Become. Here, the current supply means responds to the voltage only when the voltage supplied from the drive voltage generation means exceeds a predetermined value so that the organic EL element has a light emission state having a predetermined brightness. Current is supplied to the organic EL element, but the predetermined value is lower with a margin than the voltage value at which the organic EL element is in a light emitting state having a predetermined brightness. As this card approaches the power supply source and the intensity of the electromagnetic wave emitted from the power supply source becomes stronger, the voltage supplied from the drive voltage generating means reaches the predetermined value in the organic EL element. Current corresponding to the predetermined value starts to flow, and then the voltage supplied from the drive voltage generating means becomes a voltage sufficient for the organic EL element to be in a light emitting state having a predetermined brightness. Depending on the voltage Until flow flows, the brightness of the organic EL device is gradually brightened by a change in the current. On the other hand, when the card is moved away from the power supply source and the intensity of the electromagnetic wave irradiated from the power supply source becomes weaker, the voltage supplied from the drive voltage generating means is applied to the organic EL element. Until the current reaches the predetermined value, a current flows while the current value gradually decreases, and the brightness of the organic EL element becomes dark due to the change of the current.

  As described above, in the present invention, an antenna that receives an electromagnetic wave irradiated from a power supply source and generates an electromotive force according to the strength of the electromagnetic wave, and an organic light that emits light with brightness according to the supplied current. Based on the EL element and the electromotive force generated by the antenna, the drive voltage generating means for generating a voltage sufficient for the organic EL element to be in a light emitting state having a predetermined brightness, and the drive voltage generating means Only when the generated voltage is equal to or higher than a predetermined value that has a margin lower than the voltage value at which the organic EL element is in the light emitting state, a current corresponding to the voltage is supplied to the organic EL element. Therefore, the organic EL element has a predetermined value for supplying a current from the current supply means to the organic EL element according to the intensity of the electromagnetic wave irradiated from the power supply source. If the voltage value with a margin is lower than the voltage value in the light emitting state, the light emitting state of the organic EL element changes when the card is brought close to the power supply source or away from the power supply source. Thus, authenticity determination can be performed using the light emission state of the organic EL element, and the light emission state can be easily recognized.

It is a figure which shows one Embodiment of the card | curd of this invention, (a) is a surface figure, (b) is AA 'sectional drawing shown to (a), (c) is a figure which shows an internal structure. . FIG. 2 is a block diagram illustrating a configuration example of a control circuit illustrated in FIG. 1. It is a figure for demonstrating operation | movement of the card | curd shown in FIG.1 and FIG.2. FIG. 3 is a diagram for explaining the operation of the boost constant voltage circuit shown in FIG. 2. 3A and 3B are diagrams for explaining the operation of the constant current circuit shown in FIG. 2, in which FIG. 3A is an equivalent circuit diagram, and FIG. 3B is a diagram showing characteristics of an output current with respect to an input voltage. FIG. 3 is a block diagram illustrating another configuration example of the control circuit illustrated in FIG. 1. It is a flowchart for demonstrating operation | movement in the case of making a payment using the card | curd which has the control circuit shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1A and 1B are diagrams showing an embodiment of a card according to the present invention, in which FIG. 1A is a front view, FIG. 1B is a cross-sectional view taken along line AA ′ shown in FIG. 1A, and FIG. FIG.

  In this embodiment, as shown in FIG. 1, a substrate 20 made of an insulating material, a protective film 34 made of a transparent material, and a surface sheet 10 are laminated, and these are adhered to each other by a transparent adhesive 15. ing.

  On the substrate 20, a coiled antenna 21 is formed along the outer periphery of the substrate 20 on the laminated surface with the protective film 34, and display electrodes 31 a to 31 c are formed in a region inside the antenna 21. . Each of the display electrodes 31a to 31c has a shape indicating information to be displayed on the card 1, the display electrode 31a has a shape "A", the display electrode 31b has a shape "B", and the display electrode 31c has a shape "C". Have. On the display electrodes 31 a to 31 c, an organic EL light emitting layer 33 made of an organic EL element is laminated, and ITO 32 is laminated so as to cover the organic EL light emitting layer 33. In addition, a control circuit 35 that supplies current to the organic EL light emitting layer 33 via the display electrodes 31 a to 31 c and the ITO 32 based on the electromotive force generated in the antenna 21 is provided on the laminated surface of the substrate 20 with the protective film 34. The antenna 21 is connected to the control circuit 35, and the display electrodes 31 a to 31 c and the ITO 32 are connected to the control circuit 35 via wiring patterns 36 a and 37 b formed on the substrate 20.

  The organic EL light emitting layer 33 is composed of, for example, an organic EL element containing a polysilane derivative. When a voltage is applied to the display electrodes 31a to 31c and a current is supplied, the polysilane derivative emits light, and its light emission state is ITO 32, It will be visually recognized through the protective film 34 and the top sheet 10. If the organic EL light emitting layer 33 has the same shape as the display electrodes 31a to 31c, the display electrodes 31a to 31c are applied when a current is supplied by applying a voltage to the display electrodes 31a to 31c. The display electrodes 31a to 31c have a shape larger than the display electrodes 31a to 31c, or between the display electrodes 31a to 31c, or between the display electrodes 31a to 31c. An electrical short circuit between 31c and ITO 32 can be prevented.

  In the surface sheet 10, windows 11 a to 11 c having the same shapes as the display electrodes 31 a to 31 c and the organic EL light emitting layer 33 are formed in regions facing the display electrodes 31 a to 31 c and the organic EL light emitting layer 33. These window parts 11a-11c are formed when the surface sheet 10 is comprised from a transparent material, and areas other than the window parts 11a-11c are colored.

  FIG. 2 is a block diagram showing a configuration example of the control circuit 35 shown in FIG.

  As shown in FIG. 2, the control circuit 35 in this example generates a voltage sufficient for the organic EL light emitting layer 33 to be in a light emitting state having a predetermined brightness based on the electromotive force generated in the antenna 21. And the voltage generated by the drive voltage generation unit 40 is equal to or higher than a predetermined value that has a margin lower than the voltage value at which the organic EL light emitting layer 33 enters the light emitting state. Only when the current is generated, it is composed of a constant current circuit 43 which is a current supply means for supplying a current corresponding to the voltage to the organic EL light emitting layer 33 via the display electrodes 31a to 31c and the ITO 32, and generates a drive voltage. The unit 40 rectifies the voltage generated by the electromotive force generated in the antenna 21 and the voltage rectified by the rectifier circuit 41 with a voltage sufficient for the organic EL light emitting layer 33 to enter the light emitting state. As well as boosting in, a booster constant voltage circuit 42 for outputting to limit the upper limit voltage.

  Below, operation | movement of the card | curd 1 comprised as mentioned above is demonstrated.

  First, the basic operation of the card 1 shown in FIGS. 1 and 2 will be described.

  FIG. 3 is a diagram for explaining the operation of the card 1 shown in FIGS. 1 and 2.

  When the card 1 shown in FIG. 1 is operated, as shown in FIG. 3A, the card 1 is brought close to the reader / writer 2 in which the coiled antenna 2a is built. In the reader / writer 2, a magnetic field is generated in the direction of being emitted from the core portion of the antenna 2a by the current flowing through the antenna 2a. When the card 1 is brought close to the reader / writer 2 in this state, the magnetic field generated by the current flowing through the antenna 2a is applied to the antenna 21 of the card 1 and penetrates the coiled core portion of the antenna 21, thereby causing electromagnetic induction. An electromotive force is generated at the antenna 21 of the card 1.

  When an electromotive force is generated in the antenna 21, first, a voltage generated by the electromotive force generated in the antenna 21 is rectified in the rectifier circuit 41 of the control circuit 35, and then in the boost constant voltage circuit 42 of the control circuit 35. The voltage rectified by the circuit 41 is boosted to a voltage sufficient for the organic EL light emitting layer 33 to emit light having a predetermined brightness, and the upper limit voltage is limited and output. The electromotive force generated in the antenna 21 corresponds to the magnitude of the magnetic flux density at which the magnetic field generated by the current flowing through the antenna 2a penetrates the coiled core portion of the antenna 21, and the card 1 is the reader. The closer to the writer 2, the greater the electromotive force generated at the antenna 21.

  FIG. 4 is a diagram for explaining the operation of boost constant voltage circuit 42 shown in FIG.

  The boosting constant voltage circuit 42 shown in FIG. 2 has a boosting degree three times that of the input voltage, and 15 V is set as the upper limit of the output voltage. Therefore, as shown in FIG. 4, until the voltage output from the rectifier circuit 41 reaches 5V, a voltage that is three times the input voltage is output, and the voltage output from the rectifier circuit 41 becomes 5V. In this case, a voltage of 15V is output, and thereafter, a voltage of 15V is output even if the voltage output from the rectifier circuit 41 becomes 5V or higher. The upper limit value of the output voltage is set as a value sufficient for the organic EL light emitting layer 33 to be in a light emitting state having a predetermined brightness, and the brightness desired to be obtained by the light emission of the organic EL light emitting layer 33 is set. It can be set accordingly.

  Thereafter, in the constant current circuit 43 of the control circuit 35, a current corresponding to the voltage output from the boost constant voltage circuit 42 is supplied to the organic EL light emitting layer 33 via the display electrodes 31 a to 31 c and the ITO 32.

  Then, the organic EL light emitting layer 33 sandwiched between the display electrodes 31a to 31c and the ITO 32 emits light in the shape of the display electrodes 31a to 31c. It will be visually recognized through the window part 11a-11c of the film 34 and the surface sheet 10. FIG.

  Next, features of this embodiment will be described.

  In the organic EL light emitting layer 33, the brightness changes according to the magnitude of the flowing current. However, since the internal resistance of the organic EL element changes at the time of start-up and at the time of stability, it is when a constant voltage is supplied. Even if it exists, the brightness changes at the time of starting and when it is stable. Therefore, in order to avoid such a change in brightness, when the voltage due to the electromotive force generated by approaching the reader / writer 2 as shown in FIG. A constant current circuit 43 that supplies a constant current is used.

  FIGS. 5A and 5B are diagrams for explaining the operation of the constant current circuit 43 shown in FIG. 2, wherein FIG. 5A is an equivalent circuit diagram, and FIG. 5B is a diagram showing the characteristics of the output current with respect to the input voltage.

  As shown in FIG. 5A, the constant current circuit 43 shown in FIG. 2 is supplied with a voltage output from the boost constant voltage circuit 42 from the power source 51 and connected in series to the organic EL element layer 33. The circuit configuration is equivalent to a diode 52 and a constant current source 53 that supplies current to the organic EL element layer 33 via the Zener diode 52. The Zener diode 52 supplies a current from the constant current source 53 to the organic EL element layer 33 when a voltage of 10 V is applied. Also, the constant current source 53 stably generates and outputs a current of 1 mA when a voltage of 15 V is applied due to a change in its internal resistance. The voltage at which the current starts to flow in the Zener diode 52 is a voltage at which the organic EL light emitting layer 33 enters a predetermined light emitting state according to the intensity of the electromagnetic wave irradiated from the antenna 2a of the reader / writer 2 using the card 1. The value is lower than the value with a margin. In this embodiment, the light emission state of the organic EL light emitting layer 33 when the voltage output from the boosting constant voltage circuit 42 is 15 V based on the intensity of the electromagnetic wave irradiated from the antenna 2a of the reader / writer 2 is set to a predetermined light emission. The state is set to 10 V, which is lower than the 15 V with a margin.

  In the constant current circuit 43 configured as described above, when the voltage output from the boosted constant voltage circuit 42 is supplied from the power source 51, as shown in FIG. The current from the constant current source 53 is not supplied to the organic EL element layer 33 by the Zener diode 52. When the voltage output from the boosted constant voltage circuit 42 reaches 10 V, the current from the constant current source 53 starts to be supplied to the organic EL element layer 33. The current supplied from the constant current source 53 to the organic EL element layer 33 increases as the voltage output from the boost constant voltage circuit 42 increases. When the voltage output from the boosted constant voltage circuit 42 becomes 15 V, the current supplied from the constant current source 53 to the organic EL element layer 33 becomes 1 mA and is stabilized.

  As described above, in the constant current circuit 43 shown in FIG. 2, the voltage output from the boost constant voltage circuit 42 is the light emission state in which the organic EL light emitting layer 33 has a predetermined brightness in the boost constant voltage circuit 42. The voltage corresponding to the voltage output from the step-up constant voltage circuit 42 is satisfied only when the voltage is 10 V or more, which is lower than the upper limit value of 15 V set as a sufficient voltage with a margin of 5 V. A current is supplied to the organic EL light emitting layer 33 via the display electrodes 31 a to 31 c and the ITO 32. For this reason, the display electrodes 31a to 31c and the ITO 32 are connected from the constant current circuit 43 until the voltage output from the boost constant voltage circuit 42 reaches 15V after the voltage output from the boost constant voltage circuit 42 becomes 10V. Thus, the current supplied to the organic EL light emitting layer 33 gradually increases, and the brightness of the organic EL element of the organic EL light emitting layer 33 gradually increases due to the change in the current. On the contrary, from the state where the voltage output from the boost constant voltage circuit 42 is 15 V until the voltage output from the boost constant voltage circuit 42 reaches 10 V, the constant current circuit 43 displays the display electrodes 31a to 31a. The current supplied to the organic EL light-emitting layer 33 through 31c and ITO 32 gradually decreases, and the brightness of the organic EL element of the organic EL light-emitting layer 33 gradually becomes dark due to this change in current. Go.

  As described above, in the present embodiment, in the constant current circuit 43, the voltage output from the boosting constant voltage circuit 42 has a margin of 5V from 15V set as the upper limit value in the boosting constant voltage circuit 42. Only when the voltage becomes 10 V or more, which is a low value, a current corresponding to the voltage output from the boost constant voltage circuit 42 is supplied to the organic EL light emitting layer 33 via the display electrodes 31 a to 31 c and the ITO 32. When the card 1 is moved closer to or away from the reader / writer 2 serving as the power supply source shown in FIG. 3, the magnitude of the magnetic flux density in the antenna 21 of the magnetic field generated in the antenna 2a of the reader / writer 2 changes. When the voltage output from the boost constant voltage circuit 42 changes, the organic EL light emission occurs when the voltage output from the boost constant voltage circuit 42 is between 10V and 15V. 33 light emission state of becomes possible to change, it is possible to perform the authenticity judgment of the card 1 by the presence or absence of change in the light emission state, it is possible to easily visually recognize the light-emitting state by the change in the light emission state.

  In the above-described embodiment, the card 1 having only the function of displaying information by power supplied from the outside in a non-contact state is described as an example. However, like a general non-contact IC card, An IC chip capable of writing and reading information can be mounted, and a function that enables writing and reading of information in a non-contact state can be added.

  FIG. 6 is a block diagram showing another configuration example of the control circuit 35 shown in FIG.

  As shown in FIG. 6, the control circuit 35 in this example has a communication unit 49 added to that shown in FIG. 2, and the control unit 35 controls the rectifier circuit 41, the boost constant voltage circuit 42, and so on. The only difference is that it has a switch portion 44 for disconnecting the connection. The communication unit 49 includes a rectification function and a modulation / demodulation function, and transmits and receives information to and from the reader / writer 2 (see FIG. 3) via the antenna 21, and a memory 47 in which information is stored. The communication control unit 46 that controls the transmission / reception operation of information in the wireless unit 45 and the I / F unit 48 that outputs a signal for disconnecting the connection between the rectifier circuit 41 and the boost constant voltage circuit 42 under the control of the communication control unit 46. It consists of and.

  Hereinafter, the operation of the card 1 having the control circuit 35 configured as described above will be described by taking as an example a case where payment is performed using the card 1.

  FIG. 7 is a flowchart for explaining an operation in the case of making a payment using the card 1 having the control circuit 35 shown in FIG.

  In order to make a payment using the card 1 having the control circuit 35 shown in FIG. 6, when the card 1 is brought close to the reader / writer 2 as shown in FIG. 3, the electromotive force is applied to the antenna 21 as described above. And non-contact communication is started between the reader / writer 2 and the card 1 (step S1), and the light emitting operation of the organic EL light emitting layer 33 described above is started.

  Information stored in the memory 47 is read out under the control of the communication control unit 46, and the information is transmitted to the reader / writer 2 through the wireless unit 45 and the antenna 21, or information transmitted from the reader / writer 2. Is received by the communication control unit 46 via the antenna 21 and the wireless unit 45, whereby a predetermined settlement process is performed (step S2).

  In a state where payment is not completed, among the IC chips constituting the communication control unit 46, the port terminal that outputs a signal for disconnecting the connection between the rectifier circuit 41 and the boosted constant voltage circuit 42 is at a HIGH level. (Step S3), a signal based on the HIGH level is supplied to the switch unit 44 via the I / F unit 48. The switching elements constituting the switch unit 44 are in a conductive state when a signal at a HIGH level is supplied (step S4), whereby the rectifier circuit 41 and the boost constant voltage circuit 42 are connected. Thus, the light emitting operation of the organic EL light emitting layer 33 as described above is performed.

  Thereafter, when the settlement is completed, the port terminal of the IC chip constituting the communication control unit 46 becomes the LOW level (step S5), and a signal based on the LOW level is supplied to the switch unit 44 via the I / F unit 48. . The switching elements constituting the switch unit 44 are in a non-conducting state when a signal at the LOW level is supplied (step S6), whereby the connection between the rectifier circuit 41 and the boost constant voltage circuit 42 is cut off. Thus, the light emitting operation of the organic EL light emitting layer 33 is stopped.

  Thereby, in the payment using the card 1, it becomes possible to visually recognize whether or not the payment is completed. The switch unit 44 is not limited to be provided between the rectifier circuit 41 and the boost constant voltage circuit 42, but may be provided between the boost constant voltage circuit 42 and the constant current circuit 43.

  In the above-described embodiment, an example using the antenna 21 through which current flows by electromagnetic induction has been described as an example, but an antenna through which current flows by resonating with an irradiated radio wave is used. Also good.

  Further, in the card 1 shown in FIG. 1, the ITO 32 is laminated so as to cover the organic EL light emitting layer 33. However, in the card of the present invention, a transparent electrode, a transparent conductive film, or the like that does not use a rare metal is used. It may be used instead.

DESCRIPTION OF SYMBOLS 1 Card 2 Reader / writer 2a, 21 Antenna 10 Surface sheet 11a-11c Window part 15 Adhesive 20 Board | substrate 31a-31c, 131 Display electrode 32 ITO
DESCRIPTION OF SYMBOLS 33 Organic EL light emitting layer 34 Protective film 35 Control circuit 36a, 36b Wiring pattern 40 Drive voltage generation part 41 Rectifier circuit 42 Boosting constant voltage circuit 43 Constant current circuit 44 Switch part 45 Wireless part 46 Communication control part 47 Memory 48 I / F part 49 Communication section 51 Power supply 52 Zener diode 53 Constant current source

Claims (1)

An antenna that receives an electromagnetic wave irradiated from a power supply source and generates an electromotive force according to the intensity of the electromagnetic wave;
An organic EL element that emits light with brightness according to the supplied current;
Driving voltage generating means for generating a voltage sufficient for the organic EL element to be in a light emitting state having a predetermined brightness based on the electromotive force generated in the antenna;
Only when the voltage generated by the drive voltage generating means is equal to or higher than a predetermined value that has a margin and a lower value than the voltage value at which the organic EL element is in the light emitting state, the voltage is determined according to the voltage. And a current supply means for supplying a current to the organic EL element.

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