JP2006164164A - RF-ID media - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control writing and reading of information with respect to an IC chip according to a light receiving state without incurring a great development cost.
An IC chip 10 on which an antenna 20 is formed and connected to the antenna 20 is mounted on a base substrate 30, and information can be written to and read from the IC chip 10 via the antenna 20. In the type IC tag 1, a wiring pattern 50 for adjusting a resistance component of the antenna 20 according to a connection state with the antenna 20, and an optical switch 40 for switching a connection state between the wiring pattern 50 and the antenna 20 according to a light receiving state. Provide.
[Selection] Figure 1

Description

  The present invention relates to an RF-ID medium capable of writing and reading information in a non-contact state such as a non-contact IC card and a non-contact IC label.

  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. In addition, information is recorded on tags and labels attached to products and the like, and management of products and the like using these labels is also performed.

  In such information management using a card, tag, or label, a non-contact type IC equipped with an IC chip capable of writing and reading information in a non-contact state with respect to the card, tag, or label Cards, non-contact type IC tags, and non-contact type IC labels are rapidly spreading due to their excellent convenience.

  3A and 3B are diagrams showing a configuration example of a conventional non-contact type IC tag. FIG. 3A is a diagram showing a structure, and FIG. 3B is a block diagram showing a functional configuration.

  As shown in FIG. 3A, in the present configuration example, a coiled conductive antenna 20 is formed on a base substrate 30 made of a resin sheet or the like, and both ends of the antenna 20 are coiled. An IC chip 10 capable of writing and reading information in a non-contact state via an antenna 20 is connected and mounted.

  Further, as shown in FIG. 3B, the IC chip 10 includes a demodulator 11 that demodulates a signal received via the antenna 20 and a modulator that modulates information transmitted via the antenna 20 to obtain a modulated signal. 12, a memory 14 to which information is written, a control unit 13 for writing a signal demodulated by the demodulation unit 11 to the memory 14 as information, and a reading of information written to the memory 14, and a current flowing through the antenna 20 The power generation unit 15 generates power by rectifying the power, and the power generated by the power generation unit 15 is supplied to the demodulation unit 11, the modulation unit 12, and the control unit 13, thereby demodulating the power. The unit 11, the modulation unit 12, and the control unit 13 operate.

  In the RF-ID tag configured as described above, a current is passed from the antenna 20 to the IC chip 10 by electromagnetic induction from the information writing / reading device by being brought close to the information writing / reading device provided outside. As a result, information is written from the information writing / reading device to the memory 14 in the IC chip 10 in the non-contact state, or the information written in the memory 14 in the IC chip 10 is read / written Or read by a reading device.

Here, the above-described RF-ID medium is provided with a light receiving element that receives light and a carrier wave switch that supplies the carrier wave received by the antenna to the IC chip when receiving light by the light receiving element. (For example, refer to Patent Document 1). In this technique, for example, two light receiving elements are provided, the carrier wave switch is turned on when light is received by one light receiving element, and the carrier wave switch is turned on when light is received by the other light receiving element. By turning off, or by providing one light receiving element and receiving light by the light receiving element, turning the carrier switch on, and then turning the carrier switch off by a command from the control circuit, Information writing to and reading from the IC chip is also controlled by the light receiving state.
JP 2003-317050 A

  However, in the technique described in Patent Document 1 described above, when light is received by one of the two light receiving elements, the carrier switch is turned on and light is received by the other light receiving element. In this case, the carrier switch is turned off, or the carrier switch is turned on when light is received by the light receiving element, and then the carrier switch is turned off by a command from the control circuit. Since it is necessary to carry out with a carrier wave switch, the carrier wave switch has to be produced exclusively, and there is a problem that a great development cost is required.

  The present invention has been made in view of the problems of the prior art as described above, and controls writing and reading of information with respect to an IC chip according to a light receiving state without incurring a great development cost. An object of the present invention is to provide an RF-ID media that can be used.

In order to achieve the above object, the present invention provides:
An RF-ID medium on which an antenna is formed and an IC chip connected to the antenna is mounted on a base substrate, and information can be written to and read from the IC chip via the antenna,
A wiring pattern for adjusting a resistance component of the antenna according to a connection state with the antenna;
An optical switch is connected between the wiring pattern and the antenna and switches a connection state between the wiring pattern and the antenna according to a light receiving state.

  In the present invention configured as described above, the connection between the antenna and the wiring pattern for adjusting the resistance component of the antenna when the light is received by the optical switch and when the light is not received. The state changes. As a result, the resistance component of the antenna changes between when light is received by the optical switch and when light is not received. In the RF-ID media, the sharpness indicating the ease of reception at the antenna is determined by the inductance, capacitance, and resistance component of the antenna. Therefore, if the resistance component changes as described above, the sharpness of the antenna also changes. The resistance component consisting of the antenna itself and the wiring pattern is set to a value that allows good writing and reading of information with respect to the IC chip. In this state, when light is received by the optical switch, both ends of the wiring pattern and the antenna are connected, so that the resistance component of the antenna becomes a resistance component consisting of the antenna itself and the wiring pattern. Thus, the information can be satisfactorily written to and read from the IC chip. Also, if no light is received by the optical switch, one end of the wiring pattern is not connected to the antenna, whereby the resistance component of the antenna becomes a resistance component consisting of the single antenna and the sharpness is reduced, and the IC chip In this state, information cannot be written to or read from information.

  Thus, an existing optical switch is provided in which a wiring pattern for adjusting the resistance component of the antenna is provided according to the connection state with the antenna, and the connection state between the wiring pattern and the antenna is switched between a conductive state and a non-conductive state depending on the light receiving state. Therefore, it does not take much development cost to control the writing and reading of information with respect to the IC chip according to the light receiving state.

  As described above, in the present invention, the wiring pattern for adjusting the resistance component of the antenna is provided according to the connection state with the antenna, and the connection state between the antenna and the wiring pattern is turned on / off according to the light receiving state. Since it is configured to be switched by an existing optical switch whose state is switched, writing and reading of information with respect to the IC chip can be controlled by a light receiving state without much development cost.

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

  1A and 1B are diagrams showing a non-contact type IC tag as an embodiment of the RF-ID media of the present invention, wherein FIG. 1A is a diagram showing a structure, and FIG. 1B is a block diagram showing a functional configuration. .

  As shown in FIG. 1A, in this embodiment, a coiled conductive antenna 20 is formed on a base substrate 30 made of a resin sheet or the like, and antennas are formed at both ends of the coiled antenna 20. An IC chip 10 capable of writing and reading information in a non-contact state is connected and mounted via 20. On the base substrate 30, one end is connected to the antenna 20, and a wiring pattern 50 for adjusting the resistance component of the antenna 20 according to the connection state with the antenna 20 is formed. An optical switch 40 that is in a conductive state when receiving light is provided, and the other end of the wiring pattern 50 and the antenna 20 are connected via the optical switch 40. Thereby, in the optical switch 40, the connection state between the wiring pattern 50 and the antenna 20 is switched depending on the light receiving state.

  Further, as shown in FIG. 1B, the IC chip 10 includes a demodulator 11 that demodulates a signal received via the antenna 20, and a modulator that modulates information transmitted via the antenna 20 to generate a modulated signal. 12, a memory 14 that is a storage area in which information is written, a control unit 13 that writes a signal demodulated by the demodulation unit 11 into the memory 14 as information, and reads information written in the memory 14, an antenna The power generation unit 15 rectifies the current flowing through the power generation unit 20 to generate power, and the power generated by the power generation unit 15 is supplied to the demodulation unit 11, the modulation unit 12, and the control unit 13. As a result, the demodulation unit 11, the modulation unit 12, and the control unit 13 operate. The optical switch 40 includes a light receiving unit 41 that receives light and a switching unit 42 that is in a conductive state only when the light receiving unit 41 receives light. As this optical switch, for example, an optical diode made of a material such as Si, Ge, CdS, an optical triac, an optical transistor, a photo MOS relay, or the like can be used.

  The operation of the non-contact type IC tag 1 configured as described above will be described below.

In the non-contact type IC tag 1 configured as described above, as shown in Equation 1, an antenna is formed by the inductance (L), capacitance (C), and resistance component (R) of the coiled antenna 20. The sharpness (Q) indicating the ease of reception at 20 is determined.
Q = (1 / R) × (√C) × (1 / √L) (Formula 1)
Therefore, the inductance (L) and the capacitance (C) that determine the resonance frequency are adjusted in accordance with an information writing / reading device (not shown) that writes and reads information to and from the IC chip 10. Later, in order to adjust the sharpness (Q) without changing these values, the resistance component (R) of the antenna 20 is adjusted.

  FIG. 2 is a diagram showing the magnitude of the electromotive force due to the difference in sharpness.

As shown in FIG. 2, the greater the sharpness (Q), the greater the electromotive force at the antenna 20 at the resonance frequency f ₀ with the information writing / reading device, thereby achieving good communication. However, even if the resonance frequency slightly shifts, there is a high possibility that communication cannot be performed. That is, when the sharpness (Q) is increased, the matching range with the information writing / reading device is narrowed. On the other hand, when the sharpness (Q) is decreased, the matching range with the information writing / reading device is expanded, but the electromotive force in the antenna 20 is decreased, and the control unit 13, the demodulation unit 11, and the modulation unit 12 are operated. There is a possibility that a necessary power supply cannot be generated by the power generation unit 15. Therefore, it is necessary to set the sharpness (Q) to a desired value by adjusting the resistance component of the antenna 20.

  In this embodiment, the resistance component consisting of the antenna 20 alone is set to a value that does not allow good writing and reading of information with respect to the IC chip 10, and the resistance component consisting of the antenna 20 alone and the wiring pattern 50 is set. Is set to a value such that information can be satisfactorily written to and read from the IC chip 10 and a desired matching range can be obtained with the information writing / reading device.

  In this state, when no light is received by the light receiving part 41 of the optical switch 40, the switching part 42 is in a non-conductive state, so that one end of the wiring pattern 50 and the antenna 20 are electrically connected. Thus, the resistance component of the antenna 20 becomes a resistance component composed of the antenna 20 alone. Therefore, even when the non-contact type IC tag 1 is brought close to the information writing / reading device, the electromotive force generated in the antenna 20 is not sufficient for writing and reading information to and from the IC chip 10. Thus, information cannot be written or read with respect to the IC chip 10.

  Further, when light is received by the light receiving portion 41 of the optical switch 40, the switching portion 42 is in a conductive state, so that both ends of the wiring pattern 50 and the antenna 20 are connected, whereby the resistance component of the antenna 20 is reduced. The resistance component is composed of the antenna 20 alone and the wiring pattern 50. Therefore, when the non-contact type IC tag 1 is brought close to the information writing / reading device, a sufficient electromotive force is generated at the antenna 20 to write / read information to / from the IC chip 10, Writing and reading can be performed satisfactorily.

  In this way, the resistance component composed of the antenna 20 alone is set to a value that does not allow information to be written to or read from the IC chip 10 well, and the resistance component composed of the antenna 20 alone and the wiring pattern 50 is set. By setting the values so that a desired matching range can be obtained with the information writing / reading apparatus while the information writing / reading with respect to the IC chip 10 is satisfactorily performed, Only when light is received by the light receiving unit 41 of the switch 40, information can be written and read with respect to the IC chip 10 satisfactorily.

  In this embodiment, the sharpness of the non-contact type IC tag 1 is made different by using the difference between the resistance component of the antenna 20 alone and the resistance component of the antenna 20 alone and the wiring pattern 50, and thereby the IC Although writing and reading of information to and from the chip 10 are controlled, if the resistance component of the antenna 20 alone and the resistance component of the antenna 20 alone and the wiring pattern 50 are greatly different, light is transmitted by the optical switch 40. In the state where light is not received, the power source itself is not generated in the non-contact type IC tag 1, and the resistance component of the antenna 20 alone and the resistance component composed of the antenna 20 alone and the wiring pattern 50 are The power supply is different only to the extent that power necessary for operating the control unit 13, the demodulation unit 11, and the modulation unit 12 is not generated. If not, in a state where the light by the optical switch 40 is not received, the writing and reading of information to the IC chip 10 although the power in a non-contact type IC tag 1 is generated becomes impossible. In this case, since the power source is generated by the power generation unit 15, the response speed becomes slow when the state is changed to a state in which information can be written to and read from the IC chip 10 depending on the light receiving state of the light receiving unit 41. There is no end.

  In the present embodiment, the antenna 20 and the wiring pattern 50 are formed on one surface of the base substrate 30 and the IC chip 10 and the optical switch 40 are mounted as an example. It is also conceivable that a sheet substrate made of paper or resin is laminated on one surface or both surfaces of the base substrate 30 with an adhesive. However, even in that case, the light receiving portion 41 of the optical switch 40 needs to be exposed so that light can be received from the outside. Further, it goes without saying that the present invention can be applied not only to the non-contact type IC tag 1 but also to a non-contact type IC label or a non-contact type IC card as in this embodiment.

It is a figure which shows the non-contact type IC tag used as one Embodiment of RF-ID media of this invention, (a) is a figure which shows a structure, (b) is a block diagram which shows a function structure. It is a figure which shows the magnitude | size of the electromotive force by the difference in sharpness. It is a figure which shows the example of 1 structure of the conventional non-contact-type IC tag, (a) is a figure which shows a structure, (b) is a block diagram which shows a function structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Non-contact-type IC tag 10 IC chip 11 Demodulation part 12 Modulation part 13 Control part 14 Memory 15 Power generation part 20 Antenna 30 Base base material 40 Optical switch 41 Light-receiving part 42 Switching part 50 Wiring pattern

Claims (1)

An RF-ID medium on which an antenna is formed and an IC chip connected to the antenna is mounted on a base substrate, and information can be written to and read from the IC chip via the antenna,
A wiring pattern for adjusting a resistance component of the antenna according to a connection state with the antenna;
An RF-ID medium having an optical switch connected between the wiring pattern and the antenna and switching a connection state between the wiring pattern and the antenna according to a light receiving state.

Images