JPH07129734A - Ultrasonic ic card - Google Patents

Abstract

PURPOSE:To improve the efficiency of ultrasonic wave generation by giving a medium body for resonance amplification to an ultrasonic oscillator in an IC card. CONSTITUTION:An ultrasonic oscillator 1 which transmits and receives information by an ultrasonic wave, its electrode 11, and a medium body 3 for resonance amplification consisting of a metallic material are laminated in the IC card main body, and dimensions and materials of the ultrasonic oscillator 1 and the medium body 3 for resonance amplification are so selected that Q is high in the natural oscillation mode. The periphery of the ultrasonic oscillator 1 is filled up with an oscillation absorbent for the purpose of preventing unnecessary oscillation from being transmitted to an integrated circuit part. Since the ultrasonic oscillator is provided with the medium body for resonance amplification, the ultrasonic wave is efficiently generated.

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 or a cash payment card having an IC capable of reading and writing data by contact with the outside or contactlessly. The present invention relates to a suitable IC card, and to an ultrasonic IC card that transmits and receives information by ultrasonic waves.

[0002]

2. Description of the Related Art An IC card is a multi-function card in which an integrated circuit is embedded in a resin card base material and has a memory function or a judgment function. Information exchange with the IC card reader / writer includes a contact type and a non-contact type. The contact method is a method of transmitting and receiving information via a metal contact terminal, and has been widely commercialized. In addition, as a non-contact type, an electromagnetic coupling method that exchanges information via a coil, an electrostatic induction method that communicates via a capacitor, a radio wave method that communicates using radio waves, and an optical coupling that communicates using light There is an ultrasonic system that communicates using ultrasonic waves.

FIG. 3 shows a conventional ultrasonic coupling type non-contact IC.
3 is a cross-sectional view of an IC card showing the configuration of a part of the card 12. FIG. A disk-shaped ultrasonic transducer 15 for transmitting and receiving information is configured on a card substrate 14 in which an integrated circuit (IC) 13 is embedded and an electronic circuit 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) to vibrate ultrasonic waves. The ultrasonic wave radiated in the air is received by the ultrasonic wave transmitting / receiving unit of the IC card reader / writer device. The ultrasonic method has an advantage that it requires less electric power than other electromagnetic methods, but has a drawback that the electric power efficiency is poor as compared with the radio wave method. That is, how efficiently the vibration of the ultrasonic transducer 15 can be radiated into the air. The unnecessary vibration of the ultrasonic transducer 15 is transmitted to the electronic circuit by forming a groove between the electronic circuit portion including the integrated circuit and the ultrasonic transducer 15 and filling the groove with the cushioning material 17. Was being prevented. It is not enough to absorb unnecessary vibrations only with this groove, and attempts have been made to provide a plurality of grooves or make them larger, but this has caused problems such as weakening the strength of the card.

[0004]

In the conventional IC card, since the contact type is via the metal contact terminal, contact failure due to wear and dirt and an integrated circuit due to static electricity caused by the exposed metal contact terminal ( IC) is liable to be destroyed, resulting in low reliability. In addition, the non-contact type is an IC card and I
Since there is a space between the C-card reader / writer device and the C-card reader / writer device, for example, the electromagnetic coupling system has a drawback that it becomes large in size and a defect that requires electric power. Further, erroneous information is exchanged by a shield such as a metal piece. In addition to being dangerous, it has the drawback of not being able to communicate in some cases.

The ultrasonic coupling method requires less electric power as compared with the electromagnetic coupling method, but its efficiency is lower than that of other non-contact methods. A major issue is how to efficiently radiate the vibration of the ultrasonic transducer into the air. Further, in the conventional ultrasonic structure, vibration of the ultrasonic vibrator is transmitted to the card itself, which may cause electrical noise, damage to the built-in integrated circuit (IC), or disconnection of the wiring connected to it. There was a problem.

[0006]

According to the present invention, in order to efficiently radiate the vibrational energy of an ultrasonic oscillator into the air, the ultrasonic oscillator is provided with a medium for resonance amplification made of a thin metal plate. Adopted a structure for close contact. 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 to the card, a vibration absorbing material based on silicon resin 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 oscillator, that is, radiates vibration energy efficiently into the air. By the above-mentioned means, the vibration due to ultrasonic waves around the integrated circuit and the electronic circuit is blocked by the vibration absorbing material to prevent the vibration from being transmitted to the built-in integrated circuit (IC) or the wiring connected to the integrated circuit (IC). Quality of the IC card, while improving the reliability of the IC card.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 oscillator 1 built in an IC card body 9, and further on top of that. A thin protective sheet 7 is provided for protection. FIG. 2 also shows an embodiment of the present invention, and is an enlarged cross-sectional view of only the portion where the ultrasonic transducer 1, the electrode 11 thereof, and the resonance amplification medium body 3 are laminated. The ultrasonic vibrator 1 is made of a disk-shaped lead zirco titanate-based material having a high electromechanical coupling coefficient, and a voltage for driving vibration is applied to the electrode 11 and the resonance amplification medium body 3. The ultrasonic oscillator and the resonance amplifying medium body 3 are set so that one of the vibration modes existing in the ultrasonic oscillator 1 is infinite.
Select the dimension material of. In particular, the ratio of diameter to thickness and the material are important factors. To find these constants, use an impedance / network analyzer and look directly at the optimum constants. First, a method of obtaining the theoretical vibration mode is required, but since the ultrasonic vibrator is embedded in the plastic card substrates 5 and 6, the vibration mode cannot be determined simply, and therefore there are many errors. It is practical to obtain various constants by looking directly at the measuring instrument.

The material of the resonance amplifying medium 3 is a thin stainless plate, and the dimensions of the outer diameter / thickness and the hardness of the material are selected so that the Q is high in a certain natural vibration mode as described above. The lead-shaped zirco titanate-based material is printed on the disc-shaped stainless steel, or the thin disc-plate-shaped lead zirco-titanate-based material is thermocompression-bonded to the roughened stainless surface. Further, a silver-based electrode pattern is printed by printing or the like on another surface different from the surface provided with the resonance amplification medium body 3. With this structure, the lead zirco titanate-based material is polarized to have the function of an ultrasonic vibrator. The ultrasonic transducer 1 configured in this manner is embedded in the plastic card substrates 5 and 6 by using a silicone resin. The silicon-based resin of the vibration absorbing material 4 has a role of absorbing unnecessary vibration generated from the ultrasonic vibrator 1 and fixing the ultrasonic vibrator at the same time.

As shown in FIG. 1, the ultrasonic wave transmitting / receiving unit 8 of the IC card reader / writer device is lightly contacted with the protective sheet 7 on the resonance amplifying medium 3 to exchange information.

[0011]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, it is possible to send and receive information regardless of dirt and wear of the IC card, and even if there is a blocking object such as a metal piece, and ultrasonic vibration is applied. It can be efficiently radiated into the air. Further, it is possible to prevent damage to the built-in integrated circuit (IC) or disconnection of the wiring connected to the integrated circuit (IC) from unnecessary vibration in the ultrasonic vibrator.

[Brief description of 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 transducer portion of the ultrasonic IC card according to the present invention.

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

[Explanation of symbols]

 1 Ultrasonic Transducer 2 Integrated Circuit (IC) 3 Resonance Amplification Medium 4 Vibration Absorber 5 Plastic Card Base (Upper Lid) 6 Plastic Card Base (Lower Lid) 7 Protective Sheet 8 IC Card Reader / Writer Sound wave transmitting / receiving unit 9 IC card body 11 Electrode 12 Non-contact IC card 13 Electronic circuit unit including integrated circuit (IC) 14 Card substrate 15 Conventional ultrasonic transducer 16, 161 Conventional electrode 17 Buffer material

Claims (2)

[Claims] 1. An ultrasonic type IC card equipped with an ultrasonic transducer for transmitting and receiving information by contacting an ultrasonic wave transmitting / receiving unit of an IC card reader / writer device, wherein the ultrasonic transducer is a resonance formed of a thin metal plate. An ultrasonic IC card, characterized in that the amplifying medium body is brought into close contact with the ultrasonic transducer. 2. In order to prevent the vibration from the ultrasonic vibrator from being transmitted to the integrated circuit built in the IC card or the wiring connected thereto, a vibration absorber made of silicon resin is used as the ultrasonic vibrator. The ultrasonic IC card according to claim 1, wherein the ultrasonic IC card is arranged in the periphery.