JP3315496B2 - Ultrasonic type IC card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ID (identification) card, an electronic lock, and a cash payment card having a built-in IC capable of reading and writing data by contact with the outside or contactlessly. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suitable IC card, and to an ultrasonic IC card for transmitting and receiving information by ultrasonic waves.

[0002]

2. Description of the Related Art An IC card is a multifunctional card in which an integrated circuit is embedded in a resin card base and has a storage function or a judgment function. There are a contact type and a non-contact type for information exchange with the IC card reader / writer. The contact method is a method of transmitting and receiving information via a metal contact terminal, and has already been widely commercialized. The non-contact type includes an electromagnetic coupling method for exchanging information via a coil, an electrostatic induction method for communication via a capacitor, a radio wave method for communication using radio waves, and an optical coupling method for communication using light. There is an ultrasonic system in which communication is performed using an ultrasonic system.

FIG. 3 shows a conventional ultrasonic bonding type non-contact IC.
FIG. 2 is a cross-sectional view of an IC card showing a partial configuration of the card 12. An integrated circuit (IC) 13 is embedded, and a disk-shaped ultrasonic transducer 15 for transmitting and receiving information to and from a card substrate 14 on which an electronic circuit is configured is configured. Electrodes 16 and 161 are vapor-deposited, sputtered or printed on both surfaces of the ultrasonic vibrator 15, and a signal voltage is applied to the electrodes 16 and 161 from an electronic circuit including an integrated circuit (IC). Is activated, and the ultrasonic wave radiated into the air is received by the ultrasonic wave transmitting / receiving section of the IC card reader / writer device. The ultrasonic system has the advantage of requiring less power than other electromagnetic systems and the like, but has the disadvantage that the power efficiency is lower than that of the radio system and the like. That is, how efficiently the vibration of the ultrasonic transducer 15 can be radiated into the air. Unwanted vibration of the ultrasonic vibrator 15 is transmitted to the electronic circuit by forming a groove between the electronic circuit unit including the integrated circuit and the ultrasonic vibrator 15 and filling the groove with the buffer material 17. Was prevented. It is not enough to absorb unnecessary vibrations by using only this groove. Attempts have been made to provide a plurality of such grooves or to increase the number of grooves, but this has caused problems such as weakening the strength of the card.

[0004]

In the conventional IC card, since the contact type is provided with a metal contact terminal, a contact failure due to wear or dirt, or an integrated circuit (IC) caused by static electricity caused by the exposed metal contact terminal. IC) is likely to be broken, and the reliability is low. The non-contact type is IC card and I
Due to the presence of a space between the C card reader / writer device, for example, the electromagnetic coupling method has a disadvantage that the size becomes large and a disadvantage that requires electric power, and furthermore, erroneous information is transmitted and received by a blocking object such as a metal piece. There is a danger and, in some cases, communication is not possible.

[0005] The ultrasonic coupling method requires less power than the electromagnetic coupling method, but its efficiency is lower than other non-contact methods. A major issue is how to efficiently radiate the vibration of the ultrasonic transducer into the air. In the conventional ultrasonic structure, the vibration of the ultrasonic vibrator is transmitted to the card itself, which causes electrical noise, damages the built-in integrated circuit (IC), or disconnects the wiring connected thereto. There was a problem.

[0006]

According to the present invention, in order to efficiently radiate the vibration energy of an ultrasonic vibrator into the air, a resonance amplifying medium made of a thin metal plate is used for the ultrasonic vibrator. The structure was made to adhere. Further, in order to prevent the vibration from the ultrasonic vibrator from being transmitted to the integrated circuit built in the card or the wiring connected thereto, a vibration absorber made of a silicon resin as a base material is arranged around the ultrasonic vibrator.

[0007]

The medium for resonance amplification made of a thin metal plate increases the Q of vibration of the ultrasonic vibrator, that is, radiates vibration energy efficiently into the air. According to the above-mentioned means, the vibration caused by the ultrasonic waves around the integrated circuit and the electronic circuit is blocked by the vibration absorbing material, the vibration is prevented from being transmitted to the built-in integrated circuit (IC) or the wiring connected thereto, and information to be transmitted and received is provided. And the reliability of the IC card is improved.

[0008]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an ultrasonic IC card according to an embodiment of the present invention, in which a resonance amplification medium 3 is provided on an ultrasonic vibrator 1 built in an IC card main body 9, and further thereon. A thin protective sheet 7 is provided for protection. FIG. 2 shows an embodiment of the present invention, and is an enlarged sectional view of only the laminated portion of the ultrasonic transducer 1, its electrode 11, and the medium 3 for resonance amplification. The ultrasonic vibrator 1 is made of a disc-shaped lead zirconate titanate-based material having a high electromechanical coupling coefficient, and a voltage for driving the vibration is applied to the electrode 11 and the medium 3 for resonance amplification. The ultrasonic vibrator and the medium for resonance amplification 3 are set so as to be one specific vibration mode among the innumerable vibration modes existing in the ultrasonic vibrator 1.
Select the dimension material of. In particular, the ratio between the diameter and the thickness and the material are important factors. In order to obtain these various constants, the optimal constants are determined while looking directly at the impedance / network analyzer. First, a method for obtaining the theoretical vibration mode is required, but since the ultrasonic vibrator is embedded in the plastic card base materials 5 and 6, the vibration mode is not simply determined, so that there are many errors. It is practical to obtain various constants by direct observation with a measuring instrument.

The material of the resonance amplifying medium 3 is a thin stainless steel plate, and the dimensions of the outer diameter / thickness and the hardness of the material are selected so as to increase Q in a certain natural vibration mode as described above. A disk-shaped stainless steel is printed with a lead zirconate titanate-based material, or a thin disk-shaped lead zirconate titanate-based material is formed by thermocompression bonding on a roughened stainless steel surface. Further, a silver-based electrode pattern is printed by printing or the like on another surface different from the surface on which the resonance amplifying medium 3 is provided. With this configuration, the lead zirconate titanate-based material is polarized to have the function of an ultrasonic vibrator. The ultrasonic vibrator 1 thus configured is embedded in the plastic card bases 5 and 6 using a silicon-based resin. The silicon-based resin of the vibration absorber 4 has a role of absorbing unnecessary vibration generated from the ultrasonic vibrator 1 and also fixing the ultrasonic vibrator.

As shown in FIG. 1, an ultrasonic wave transmitting / receiving section 8 of an IC card reader / writer device is lightly brought into contact with a protective sheet 7 on an upper part of a resonance amplification medium 3 to transmit and receive information.

[0011]

Since the present invention is configured as described above, it is possible to exchange information regardless of dirt and wear of the IC card, and further, regardless of a blocking object such as a metal piece. It can radiate efficiently into the air. Further, damage to the built-in integrated circuit (IC) or disconnection of wiring connected thereto can be prevented from unnecessary vibration in the ultrasonic transducer.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an ultrasonic IC card according to the present invention.

FIG. 2 is a sectional view of an ultrasonic vibrator portion of the ultrasonic IC card according to the present invention.

FIG. 3 is a partial sectional view of a conventional ultrasonic IC card.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ultrasonic transducer 2 integrated circuit (IC) 3 medium for resonance amplification 4 vibration absorbing material 5 plastic card base material (top cover) 6 plastic card base material (lower cover) 7 protective sheet 8 IC card reader / writer device Sound wave transmitting / receiving section 9 IC card main body 11 Electrode 12 Non-contact IC card 13 Electronic circuit section including integrated circuit (IC) 14 Card board 15 Conventional ultrasonic vibrator 16, 161 Electrode by conventional method 17 Buffer material

Claims (2)

(57) [Claims] 1. An ultrasonic IC card having an ultrasonic vibrator for transmitting and receiving information by bringing an ultrasonic wave transmitting / receiving section of an IC card reader / writer device into contact with the ultrasonic vibrator, the ultrasonic vibrator being made of a metal thin plate and having a resonance made of a thin metal plate. An ultrasonic IC card having a structure in which an amplifying medium is brought into close contact with the ultrasonic vibrator. 2. In order to prevent the vibration from the ultrasonic transducer from being transmitted to an integrated circuit built in the IC card or a wiring connected to the IC card, a vibration absorber made of silicon resin as a base material is used for the ultrasonic transducer. 2. The ultrasonic IC card according to claim 1, wherein the IC card is arranged on the periphery.