JPH02307792A - Ic card - Google Patents

Abstract

PURPOSE:To prevent breakdown of hardware or stored data in an IC card by providing a device to warn the user when physical stress beyond a specified level is detected. CONSTITUTION:Stress sensors 202, 202 are fixed inside the enclosures 205, 205 on the front and rear of an IC card using an adhesive. The stress sensor 202 is composed of piezoelectric elements which generate an electric signal at a voltage proportional to a distortion applied, if the card is bent on the front or rear. A stress detection circuit 105 compares an output from the stress sensor 202 with a specified reference value to drive a buzzer 106. In this way, a warning is sounded that an excess stress is applied to the card. The threshold value of the stress detection circuit 105 is determined on the maximum stress applied to the card which is premeasured.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention is an IC card, particularly a memory, a means for inputting and outputting data to the memory, and a control unit for controlling data input and output processing to the memory, which are housed inside the device exterior. I will do it
This concerns the C card.

[Prior Art] IC cards have been known that include a built-in memory such as a ROM or RAM, or a CPU that controls input/output of the memory. Such an IC card is considered to be used as an external storage device for electronic equipment or as a substitute for various ID cards, prepaid cards, etc. using conventional magnetic cards.

Usually, an IC card has an exterior made of plastic or the like, has a thickness of about 3 mm, and is configured so that it cannot be easily bent. However, recently, as semiconductor chips have become smaller and smaller, the thickness of IC cards has gradually become smaller, approaching the same thickness as conventional credit cards. Thinner IC cards are preferable as they have the advantage of being easier to store in card slots, etc.
On the other hand, because of its thinness, there is a risk that it will be handled roughly and a large amount of physical stress will be applied to the card. There was a risk that this stress would damage the connecting parts of the internal circuits, damage the circuits within the IC card, and destroy the data stored or stored in the memory within the card.

SUMMARY OF THE INVENTION An object of the present invention is to provide an IC card that can solve the above problems and prevent destruction of the IC card's hardware or stored data due to physical stress.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, a memory, means for inputting/outputting data to the memory, and a control unit for controlling data input/output processing to the memory are installed inside the exterior of the device. In an IC card stored in an IC card, there is provided a means for detecting physical stress on the device exterior or a circuit member inside the device, and a means for detecting physical stress of a predetermined value or more by the detecting means, and a means for detecting physical stress in the IC card. We adopted a configuration that provides a means to notify the user.

[Function] According to the above configuration, if a physical stress exceeding a predetermined value is applied to the IC card, the user can be warned of this.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows the configuration of an IC card employing the present invention. In the figure, reference numeral 100 denotes a CPU comprised of a microprocessor, etc., and a ROM 10I, a RAM 102, and an interface section 103 are connected to a signal bus of this CPU 100.

The CPU 100 connects the interface unit 1 to the RAM 102 according to the program stored in the ROM10I.
Controls data input/output to/from external devices via 03. The interface section 103 is composed of various known input/output ports for serial or parallel data input/output.

Each of the above parts is driven by a battery 104, such as a lithium battery, housed in the card.

In the configuration shown in FIG. 1, a stress detection circuit 105 is provided to detect physical stress applied to the IC card. A stress detection circuit 105 detects physical stress on the card, and when this reaches a constant value, it drives a buzzer 106 made up of a piezoelectric buzzer or the like to issue a warning to release the stress applied to the card. .

FIG. 2 shows the configuration of the stress detection port 8105 in FIG. 1. FIG. 2 shows the cross-sectional structure of the IC card. In FIG. 2, reference numerals 205 and 205 denote exteriors made of plastic or the like that constitute the exterior of the card, and these exteriors 205.
A circuit board 204 is held between the two 205 via a spacer such as a card edge.

A space 201 is defined between the exterior 205, 205 and the circuit board 204, in which each circuit member shown in FIG. 1 is mounted. A battery 104 and a buzzer 106 are mounted on the circuit board 204. Stress sensors 202 and 202 are respectively fixed to the inside of the front and back exteriors 205 and 205 by a method such as adhesion.

The stress sensor 202 is composed of a piezo element, etc.
As shown at the bottom of the figure, when the card is folded from either the front side or the back side, the stress sensor 202 generates an electrical signal with a voltage proportional to the applied strain.

The stress detection circuit 105 compares the output of the stress sensor 202 with a predetermined reference value to drive the buzzer 106 to warn with a beeping sound that excessive stress is being applied to the card. The threshold value of the stress detection circuit 105 may be determined in accordance with the maximum stress on the card measured in advance.

With this configuration, if an IC card is bent and more stress than necessary is applied, the user can be warned and cautioned when handling the card, and the circuit inside the card or the data stored in the RAM 102 can be Destruction can be prevented.

Next, the mounting position of the stress sensor will be considered in more detail.

FIG. 3 shows an example of a preferable arrangement position of the stress sensor. In the above example, the stress sensor is provided over the entire surface of the IC card, but below, consideration will be given to placing the stress sensor only on a portion of the IC card.

Figure 3 is a plan view of the IC card, with the symbol 30 at the center of the card.
1 indicates the position of the chip built into the card.

As shown from the side at the bottom of FIG.
When the card is folded about 5 as shown in the figure, a stress having a vector as shown at 304.304 is applied to the edge of the card. A broken line 306 indicates a reference line in a state where no bending stress as described above is applied to the card.

In such a bending state, the P of the card end is usually
It is considered that the intersection angle θ between the tangent passing through the point and the reference line 306 is maximum, that is, the largest distortion occurs near point P.

If a stress sensor made of a piezo element or the like is placed in the area 302 at both ends of the card, that is, the area that includes a line passing through point P and perpendicular to the long side of the card, stress on the card can be detected most sensitively. can do.

In addition, when detecting stress perpendicular to the surface of an IC card, as shown in FIG.
A stress sensor is provided in a region 401 so as to cover a part of the region 400 including terminals 1, peripheral parts, etc.

With this configuration, it is possible to sensitively detect the stress perpendicular to the card surface when the card is placed on a flat surface and the central part of the card is pressed down with a finger, thereby preventing damage to the built-in chip. It can be prevented.

Although the region 400 and the stress sensor region 401 are shifted from each other in FIG. 4, they may completely overlap on a plane. Moreover, such a configuration also provides the effect of protecting the chip in which the stress sensor itself is built. In the case of Figure 3, the stress applied to the IC chip built into the card can be detected early at the position where the most distortion occurs, but in the case of Figure 4, it is not possible to directly detect the stress applied to the chip itself. can.

Although a configuration has been described above in which stress is notified by a buzzer, it is also possible to issue a stress abnormality warning by light emission information using an LED or the like.

Also, IC cards that comply with ISO standards are known that have serial interface input/output parts on the flat surface of the card, but such IC cards do not have a stress sensor between the interface part (connector) and the space inside the chip. It is possible to prevent damage to the delicate connector connection parts of the interface part.

In the above, a piezo element was exemplified as a stress sensor, but two
It goes without saying that a similar stress sensor can also be constructed using a contact switch or the like in which two electrodes are arranged facing each other.

[Effects of the Invention] As is clear from the above, according to the present invention, a memory, means for inputting and outputting data to the memory, and a control unit for controlling data input and output processing to the memory are housed within the exterior of the device. In the IC card, a means for detecting physical stress on the device exterior or a circuit member inside the device, and when the detection means detects physical stress of a predetermined value or more, a notification to that effect is provided to the user of the IC card. Since the structure is equipped with a means to prevent damage to the IC card, it is possible to warn the user if physical stress exceeding a predetermined level is applied to the IC card, thereby preventing damage to the IC card's hardware or stored data due to physical stress. It has the excellent effect of being able to prevent it from happening.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of an IC card adopting the present invention, Fig. 2 is an explanatory diagram showing the cross-sectional structure of the IC card of Fig. 1, and Fig. 3 shows different placement positions of the stress sensor. FIG. 4 is an explanatory diagram showing further different positions of stress sensors.・100...-CPU 101...ROM102
---RAM 103... Interface section 104--... Battery 105... Stress detection circuit 10
6... Buzzer 202... Stress sensor 204...
・Circuit board 205...External device lゝ

Claims (1)

[Scope of Claims] 1) An IC card in which a memory, means for inputting and outputting data to the memory, and a control unit for controlling data input and output processing to the memory are housed inside the device exterior, or inside the device. An IC card characterized in that it is provided with a means for detecting physical stress on a circuit member, and a means for notifying a user of the IC card when a physical stress exceeding a predetermined value is detected by the detecting means. . 2) The IC card according to claim 1, wherein the stress detection means is disposed at a position where the device exterior causes maximum distortion when a predetermined stress is applied to the device exterior. 3) The IC card according to claim 1 or 2, wherein the stress detection means is arranged so as to cover a predetermined member provided on the exterior of the device or inside the device. 4) The IC card according to any one of claims 1 to 3, wherein the notifying means notifies the application of a physical stress of a predetermined value or more by means of light emission information or audible audio information.