JP3263867B2 - IC card detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card detecting method for electrically detecting that an IC card having a built-in CPU circuit is mounted on a device.

[0002]

2. Description of the Related Art Recently, an IC card having a CPU circuit built in a portable telephone has begun to be used. An advantage of this case is that the IC card has algorithms, storage of data, telephone subscriber numbers, and the like, and if a telephone subscriber uses the same IC card, the usage fee will be reduced. Subscriber schemes have been implemented. From such a background, in a mobile phone using an IC card, it is necessary that the IC card is securely inserted.

[0003] Here, the I / O with the above-mentioned CPU circuit built-in.
An example of the C card will be described with reference to FIGS. An IC card generally designated by reference numeral 1 includes a CPU circuit 6 including a ROM (program memory) 4 and a RAM (data processing memory) 5 and an EEPROM (data memory).
7 is built-in. Further, on the surface of the IC card 1, an input / output terminal unit 2 including a plurality of terminal groups for transmitting and receiving signals to and from an interface unit of the terminal device 8, which will be described later, is provided.

The above-mentioned input / output terminal unit 2 is used for the IC card 1
The position is defined by the ISO standard (International Organization for Standardization). Each terminal of the input / output terminal unit 2 is formed in two rows of four, and each terminal includes 2a to 2h. To explain the details of each terminal, terminal 2a is VCC (operating voltage supply terminal of CPU in the card), and terminal 2b is RST
(Reset signal supply terminal for CPU in card), terminal 2c
Is a CLK (operation clock supply terminal of the CPU in the card), a terminal 2d is an RFU (spare terminal), and a terminal 2e is
GND (ground), terminal 2f is VPP (memory IC
, A terminal 2g is an I / O (bidirectional data transmission terminal), and a terminal 2h is an RFU (reserve terminal).

The magnetic stripe 3 is formed on the surface of the IC card 1, and the direction of the arrow of the IC card 1 is the direction of insertion into the terminal device.

[0006]

The IC card 1 as described above is generally used by interfacing the IC card 1 and the terminal device 8 through an IC card read / write (R / W) 9 (hereinafter referred to as an interface unit). Is done. As a system used in such a method, there are a pay TV, a POS (point of sale information management system), and the like, in addition to the above-mentioned mobile phone. Here, the most important point is I
Since the C card 1 has the built-in CPU circuit 6, it is a highly reliable device in terms of security.

Here, an example of application in the field of the mobile phone will be described. Recently, as an internal function of an IC card, an encryption code for controlling the secret of communication, ID collation for confirming a user, Mainly, storage and updating of each data accompanying the communication are performed. However, there are those who try to violate the security of such highly reliable devices by mishandling them. For example, there is a case where illegal means such as forcibly removing the IC card attached to the interface unit of the terminal device while the terminal device is operating is performed.
For such improper handling, it is often necessary for the terminal device to confirm that the IC card is mounted, other than exchanging data during operation with the IC card.

[0008] In addition, when a meaningless command is output to the IC card as a method for performing the software, a certain status is returned from the device. If there is no response, it is determined that the IC card has been removed. You can check from the side. However, in the mobile phone, except when the battery operation for the data exchange with the original IC card has become a basic, it is necessary to suppress the power usage as much as possible to set the IC card to sleep (sleep) mode is there. In the above-described software method, the IC card changes from the sleep mode to a normal active state, and the effect of suppressing power consumption is not expected much.

[0009] A method of detecting the mounting of an IC card using a microswitch has been conventionally known. The use of the microswitch requires a part larger than the thickness of the IC card besides the terminal for operating the IC card. However, if the device itself that uses the IC card as a part of the system is large, the ratio of the interface portion of the IC card and the terminal device to the whole becomes small. However, in mobile phones that are currently being implemented, even products that fit in pockets must be considered, and therefore, the communication method itself is also digitized, and the ratio of the parts necessary for communication to the whole becomes large. The mechanical section such as the interface section is particularly limited in the thickness direction, and it is difficult to achieve the original purpose by the above-described conventional method.

There is also an example in which a photointerrupter combining a photodiode and a light emitting diode is used as another detecting means instead of the microswitch. This is a device in which an electric current is applied to a light emitting diode to emit light, and the light is received by a photodiode. In other words, the forward resistance is low during light emission of the photodiode, but when light reception to the photodiode is obstructed, the forward resistance changes and becomes high. Therefore, it is possible to detect the mounted state of the IC card using such a property.

For the reasons described above, it can be seen that the use of microswitches and photointerrupters conventionally used is particularly difficult for small portable telephones.

[0012] From such a background, the present applicant has proposed an IC card detection device which has a simple mechanism, can contribute to miniaturization, and can mechanically confirm the mounting of the IC card.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is an electric method that can achieve a security effect and power saving.
The purpose is to obtain a card detection method.

[0014]

In order to achieve the above object, an IC card detecting method according to the present invention detects the mounting of an IC card by a control circuit provided in an interface section of a device. It is like that.

[0015]

The IC card detecting method according to the present invention as described above is characterized in that the power supply to the IC card is turned on.
It is determined whether or not the IC card is in an operation mode for suppressing power consumption. If the operation mode is in the operation mode, it is determined that the IC card is mounted.
To detect the presence or absence of a current supplied to the IC card, current Tokoro
If the value is above the set value, it is recognized that an IC card is installed
Is done.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an IC card detection method according to the present invention will be described with reference to the drawings shown in the embodiments. The configuration of the IC card denoted by reference numeral 1 is as shown in FIG.
The C card 1 is mounted on the interface unit of the terminal device, and is electrically activated after mechanical contact of the input / output terminals 2a to 2h of the IC card 1 to perform data exchange.
At the end of the data exchange, it is electrically deactivated again, and then the mechanical contact is cut off by removing the IC card.

Next, a procedure in which the IC card activates the terminal device through the interface unit of the terminal device will be described with reference to the flowchart shown in FIG.

First, in S31, the I / O terminal of the input / output terminal for exchanging data with the IC card is set to the TTL level "H". Next, in step S32, the Vcc terminal is turned on to supply power inside the IC card. Then, in step S33, the EEPROM built in the IC card is turned on.
The program power supply Vpp of M7 is turned on (this IC is not connected internally in this example, although some IC cards do not use the program power supply Vpp). Subsequently, in S34, it is determined whether or not the IC card is mounted on the terminal device. If the determination is Yes, in order to operate the IC card from the reset state, the RST terminal is set to the TTL level “H” in S35, and the activation procedure ends.

Next, the procedure in the communication mode between the IC card and the terminal device will be described with reference to the flowchart shown in FIG.

First, in S41, the CP in the terminal device is
U outputs a command to the IC card, and at this time, S4
In step 2, it is confirmed whether an IC card is mounted. If it is determined that the IC card is in the mounted state, the command is transferred to the IC card through the I / O terminal in step S43. That mistake, S
At 44, the result and / or status of the command from the IC card is transferred to the terminal device through the I / O terminal. After this transfer is completed, at S45
It is determined whether or not the card is to be deactivated. If the card is not deactivated, the process returns to step S41 to wait for the next command. If the card is deactivated, the process proceeds to the deactivation procedure.

Next, the inactivation procedure will be described with reference to the flowchart shown in FIG. 5.
The processing is substantially the reverse of the activation procedure described in. First,
In S51, the RST terminal is set to the TTL level “H” to stop the operation of the CPU circuit in the IC card. Next, in step S52, the power of the EEPROM in the IC card is turned off, and in step S53, the power supply Vcc supplied to the IC card is turned off. Finally, in S54, I
The output of the terminal device connected to the / O terminal is set to a high impedance state, and the IC card is removed.

The processing in S34 in FIG. 3 and the processing in S42 in FIG. 4 are the same and are the gist of the present invention, and therefore, this part will be described in detail later.

FIG. 6 shows a Vcc terminal of an IC card controlled by a CPU of a terminal device and a detection circuit for detecting an IC card mounted state.

The transistor T61 is connected to the Vc of the IC card.
When the transistor T61 is turned on and off, the power supply to the Vcc terminal is controlled. The transistor T62 functions as a buffer for enabling the transistor T61 to be driven from the TTL level of the latch IC 63.

The resistors R64 and R65 are pull-up resistors of the transistors T61 and T62, respectively.
The resistor R66 is directly connected to the transistor T6 from the latch IC 63.
2 is a protection resistor provided for limiting an overload of the output of the latch IC 63 when driving the latch IC 63. The resistor R67 detects the current flowing into the IC card connected to the emitter of the transistor T61. If this resistor has an excessively large resistance value, the voltage drop across the resistor R67 increases, and the resistance of the transistor T61 increases. Is turned on, the output voltage drops, so the value is set to a very small value so that the effect of the transistor T61 can be ignored. The comparator IC68 has both ends of the resistor R67 connected as inputs. For example, the input IC68a
And the voltage of IC 68b is the same, the comparator IC6
The output from 8 is a TTL level "L", and if there is a voltage difference, it is a TTL level "H".

Next, the operation of the detection circuit configured as described above will be described. Now, a setting is made so that the CPU of the terminal device turns on the transistor T61 via the latch IC 63 to supply power to the IC card (S in FIG. 3).
32), if an IC card is mounted, current flows through the IC card via the resistor R67 and the collector of the transistor 61 via the emitter. Thus, although very a small value potential difference occurs across the resistor R67, the potential difference comparator IC68 is TT
L level changes from “L” to “H” level, and as a result,
The attachment of the IC card is detected.

If an IC card is not mounted, no current flows through the resistor R67, and no potential difference occurs between both ends of the resistor.
8, the input IC 68a and the IC 68b have the same voltage, and the output from the comparator IC 68 has the TTL level “L”. Therefore, the CPU of the terminal device reads and determines these TTL levels “H” and “L” (the processing of S34 in FIG. 3 and the processing of S42 in FIG. 4).

Next, the procedure for making the above-described CPU read determination will be described with reference to the flowchart shown in FIG.

First, in S71, it is determined whether or not the CPU of the terminal device is in a state where the power supply Vcc of the IC card is being supplied. If not, the activation of the IC card has not been completed yet. After determining the normality in S75, the process ends. On the other hand, if it is in the ON state, the CPU of the terminal device determines in S72 whether or not the sleep mode is being set in the IC card. Since the current consumed by the IC card in the sleep mode is extremely small, the comparator IC 68
This must be done because the output may contain errors. At this time, if it is determined that the mode is the sleep mode, the normality is determined in S75 and the process is terminated. On the other hand, if it is determined that the mode is not the sleep mode, I
The C card is detected, that is, the output of the comparator IC 68 is read to make a determination. If it is determined that the IC card has been detected, it is determined that the IC card has not been illegally removed, and a normal determination is made in S75. And exit. If no IC card has been detected, it is determined that an illegal removal has been performed, an abnormality is determined in S74, and the process ends.

As described above, the IC card detection method of the present invention detects the operation of the IC card due to unauthorized use, performs necessary processing corresponding to the operation inside the terminal device, and provides a high security function for IC card detection. Obtainable.

In the IC card detection method according to the present invention, the load current can be detected by using the potential difference generated between both ends of the resistor as described above. Therefore, a simple detection circuit may be used. It can also be used as a power supply circuit for supplying power to the Vcc terminal of the IC card. Further, even when the IC card is in the sleep mode and the current consumption is small, it can be detected by combining with the software.

The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention.

[0033]

As described above, the IC according to the present invention is
Card detection method, the power supply is turned on der to the IC card
When the IC card operates in an operation mode that suppresses power consumption
It is determined whether or not the IC card is in operation mode.
Mode is determined to be installed, and it is not in operation mode
Detects the presence or absence of the current supplied to the IC card,
Is greater than or equal to a predetermined value, the IC card is
Since as will be appreciated, in the suppression mode power consumption
Misjudgment of presence / absence of device by detecting extremely small current
And more accurate judgment can be made. Further, the detection of the mounting of the IC card can be electrically performed without using any mechanical means, and thus the conventional mechanical mechanism can be used as it is. Further , the size of the device can be reduced, and the cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of an IC card used in the present invention.

FIG. 2 is a block diagram of IC card signal processing.

FIG. 3 is a flowchart of an IC card activation procedure.

FIG. 4 is a flowchart of a procedure during a communication mode between the IC card and the CPU of the terminal device.

FIG. 5 is a flowchart of an IC card inactivation procedure.

FIG. 6 is an IC card detection circuit diagram according to the present invention.

FIG. 7 is a flowchart of a procedure for determining whether to mount an IC card.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC card 2 Input / output terminal part 2a Vcc terminal 2b RST terminal 2g I / O terminal 6 CPU circuit 8 Terminal equipment 9 Interface part T61, T62 Transistor IC63 Latch R64-R67 Resistance IC68 Comparator

Claims (1)

(57) [Claims] 1. An IC card detection method for determining whether or not an IC card is attached to a device, wherein the device is powered on when the IC card is powered on.
At a certain time, it is determined whether or not the IC card is in an operation mode for suppressing power consumption . If the operation mode is the operation mode, it is determined that the IC card is mounted. Supplied to the above IC card
The presence or absence of a current to be detected is detected .
A method of detecting an IC card, comprising determining that the IC card is mounted.