JP2004303162A - Information reader and program for information reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent information read from an information storage medium, from being illegally acquired by a third person even when data erasing processing is forcibly stopped halfway. <P>SOLUTION: In a magnetic card reader, voltage waveform data obtained from output signals of a magnetic head, jitter data of pulse waveform obtained from the spacing of peak values of the voltage waveform data, bit data obtained by converting the jitter data into logical data of 0 and 1, and character data obtained by converting the bit data into character data, are stored in data storage regions R1-R4 of an RAM respectively. After transmitting the data to a host device, the data stored in the data storage regions R1-R4 is erased in order from small data capacity, i.e. in the order of character data, bit data, jitter data and voltage waveform data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an information reading apparatus for reading information stored in an information storage medium, and more particularly to an apparatus having a function of erasing read information after use.
[0002]
[Prior art]
As an information reading device that reads information from an information storage medium, there is a card reader that reads information from a medium such as a magnetic card or an IC card. When a card is inserted by a user, the card reader reads the inserted card into the main body and reads information from the card. Then, after storing the read information in a memory such as a RAM, the information is read from the memory and transmitted to the host device. The host device that has received the read information performs a predetermined process based on the information, and when the process is completed, notifies the card reader of the completion of the process. The card reader that has received this notification ejects the card from the inside of the main body, returns the card, and ends the processing for the card. The read information stored in the memory of the card reader is updated to the read information of the next card when the information is read from the next inserted card. That is, the information read from the previous card remains stored in the memory until the information read from the next card is updated.
[0003]
However, if the read information remains stored in the memory as described above, after returning the card, a malicious third party forcibly opens the card reader and steals information from the memory. The read information may leak to a third party. If the read information is leaked to a third party, the card may be forged from the information and abused, so that a measure for preventing the leak of the read information is required. Therefore, as a countermeasure, it is conceivable to delete the information stored in the memory after a predetermined process is completed in the card reader.
[0004]
Prior art techniques for preventing information leakage by erasing the contents stored in a memory include, for example, Patent Documents 1 to 3 described below. Patent Document 1 discloses that information is read from an external storage medium and stored in a memory, the information in the memory is written to an IC card, and the information is erased from the memory after the issuance of the IC card is completed. A technique for ensuring security is described. Patent Document 2 discloses that data to be stored is divided into data pieces and stored in a plurality of memories, and when it is detected that a certain memory has been illegally removed, data in another memory is erased. It describes a technology that prevents confidential information from being analyzed by a third party. Japanese Patent Application Laid-Open No. H11-163873 discloses that when commands transmitted to and received from an external device do not follow a predetermined order, key data stored in a memory is erased to enable communication with an illegally connected device. A technique for preventing data leakage is described.
[0005]
[Patent Document 1]
JP 2001-291064 A [Patent Document 2]
Japanese Patent Application Laid-Open No. 2002-73422 [Patent Document 3]
JP-A-2002-94501
[Problems to be solved by the invention]
By the way, in the information reading device, the capacity of data stored in the memory varies depending on the type of information. For example, in a magnetic card reader, a change in magnetic force of information recorded on a magnetic card is taken out as a change in an analog voltage, the analog voltage is sampled and converted into digital voltage waveform data, and this voltage waveform data is converted into a pulse waveform. The data is converted into jitter data, which is further converted into bit data of "0" and "1", and finally, the bit data is converted into character data which is character data. These voltage waveform data, jitter data, bit data, and character data are temporarily stored in predetermined areas of a memory (RAM). When the capacity (data length) of these data is represented by a ratio, when the character data is 1, the bit data is 5 to 10, the jitter data is 10, and the voltage waveform data is 300, for example.
[0007]
Here, in order to prevent the data stored in the memory from being illegally acquired, if the contents of the memory are to be erased after transmitting the data to the higher-level device, while the erasing process of all the data is not completed, In some cases, a malicious third party forcibly stops the erasing process. That is, if the data is erased in the order of, for example, voltage waveform data → jitter data → bit data → character data, as described above, the voltage waveform data is several hundred times as large as the jitter data and bit data as compared to the character data. Since the data length is several tens of times in comparison, it takes time to erase. Therefore, if the erasing process is forcibly stopped during the erasing of the voltage waveform data, it is impossible to completely restore the voltage waveform data because some of the voltage waveform data has already been erased. Data, bit data and character data are left in the memory without being erased. This makes it possible for a third party to acquire such information remaining in the memory. In particular, the character data is obtained by completely demodulating the information recorded on the magnetic card, for example, the credit card number itself. Therefore, if a malicious third party acquires the card, the card is easily forged and misused.
[0008]
As described above, conventionally, no consideration was given to the erasing order of the information stored in the memory. Therefore, if the erasing process is stopped before all the data is erased, the data remaining in the memory is illegally disclosed to a third party. There was a risk of being acquired. Regarding such a problem, no countermeasure is taken in Patent Documents 1 to 3 described above.
[0009]
The present invention solves the above-mentioned problems, and the problem is that even if the data erasing process is forcibly stopped halfway, the information read from the information storage medium can be transmitted to a third party. It is to prevent unauthorized acquisition.
[0010]
[Means for Solving the Problems]
An information reading apparatus according to the present invention includes a reading unit that reads information from an information storage medium, a storage unit that stores the read information read by the reading unit, and a transmission unit that transmits the read information stored in the storage unit to a higher-level device. And erasing means for erasing the read information stored in the storage means after the transmitting means has transmitted the read information to the host device. The erasing means is configured to perform erasing in order from the information having the smaller data capacity among the read information stored in the storage means.
[0011]
In this way, even if there are several types of data, erasure of information having a small data capacity can be completed in a short time, and erasure of information having a large data capacity can be started as soon as possible. Therefore, even if a third party forcibly stops the erasing process on the way, information having a small data volume has already been erased at that time, and there is no possibility that the information is illegally acquired by the third party. On the other hand, for information having a large data capacity, it is impossible to completely restore the information if it cannot be completely erased but partially erased, and even if acquired by a third party, it is abused There is no fear. Even if all of them remain, it is difficult to analyze and demodulate them due to the large data capacity, so that the risk of leakage to a third party can be reduced.
[0012]
Further, in the present invention, the storage means has a storage management area in which a storage position and a data capacity of each read information stored in the plurality of data storage areas are recorded. Then, the erasing means refers to the storage management area and erases the information in order from the information having the smaller data capacity. If the data storage area is fixedly assigned in advance according to the type of data, it is sufficient to simply delete the data from the area with the smaller storage capacity, but if the data storage area is not assigned, I can't do that. Therefore, by providing the storage management area as described above, it is possible to reliably erase information having a small data capacity without allocating a data storage area.
[0013]
The present invention is typically applied to a magnetic card reader. In this case, a magnetic head is provided as a reading unit. The magnetic head detects a change in the magnetic force of a magnetic card on which information is magnetically recorded, converts the change into a change in voltage, and outputs the change. Also, a change in the voltage output by the magnetic head is converted into voltage waveform data, the voltage waveform data is converted into jitter data that is pulse waveform data, and the jitter data is converted into bits that are logical data of “0” and “1”. Conversion means for converting data into data and converting bit data into character data which is character data is provided. Furthermore, storage means having areas for storing voltage waveform data, jitter data, bit data, and character data respectively, transmission means for transmitting data stored in the storage means to a higher-level device, and this transmission means There is provided an erasing means for erasing data stored in the storage means after transmitting the data to the host device. The erasing means erases the data stored in the storage means in the order of character data, bit data, jitter data, and voltage waveform data.
[0014]
As described above, when comparing the data capacities, there is a relationship of character data <bit data <jitter data <voltage waveform data. On the other hand, the order of data conversion is in the order of voltage waveform data → jitter data → bit data → character data. Each time data conversion is performed, the data capacity becomes smaller and decoding becomes easier. Since the finally restored character data has the smallest data capacity, if it is leaked to a third party, it is likely to be easily decrypted and misused. Therefore, as described above, by erasing character data in order from the smallest data capacity, data that is easy to decipher can be promptly erased at an initial stage, thereby preventing leakage to a third party. . Also, if part of the voltage waveform data has already been erased, it is impossible to restore the character data from it, and even if all the voltage waveform data remains, the data capacity is large. It is difficult to analyze the character data and demodulate the character data, so that the risk of leakage to a third party can be reduced.
[0015]
The character data in the present invention is typically identification information unique to a magnetic card, such as a credit card number, a bank account number, and a personal identification number. If such information is obtained fraudulently by a malicious third party, there is a high risk that the card will be forged and misused.However, by erasing the character data first, the damage caused by the card forgery can be anticipated. Can be avoided.
[0016]
Also, the information reading device program according to the present invention includes a reading process of reading information from an information storage medium, a storing process of storing the read information in a storage unit, and transmitting the read information stored in the storage unit to a host device. This is a program that causes the CPU to execute a transmission process of transmitting the read information to the host device and an erasing process of sequentially deleting the read information stored in the storage unit from the information having the smaller data capacity. By using this program, it is possible to respond only by changing the firmware without changing the hardware of the existing information reading device.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing a schematic structure of a magnetic card reader. In FIG. 1, reference numeral 10 denotes a magnetic card reader, which is connected to a host device 30 (shown in FIG. 2) such as an automatic cash transaction processing device. Reference numeral 1 denotes a main body of the magnetic card reader 10, and 1a denotes an internal space of the main body 1 (hereinafter, referred to as a main body inside). Reference numeral 2 denotes a magnetic card on which predetermined information is magnetically recorded on a magnetic stripe (not shown). 2a is the front end of the magnetic card 2, and 2b is the rear end. Reference numeral 3 denotes an insertion slot into which the magnetic card 2 is inserted. Reference numeral 4 denotes a pair of upper and lower rollers which are rotated by a motor 15 (shown in FIG. 2). The roller 4 conveys the magnetic card 2 in the forward direction F when the motor 15 is driven to rotate forward, and moves the magnetic card 2 when the motor 15 is driven to rotate reversely. It is transported in the backward direction B. Reference numeral 5 denotes a magnetic head arranged so as to be in contact with the magnetic card 2 to be conveyed, and reads information magnetically recorded on the magnetic card 2. More specifically, the magnetic head 5 detects a change in the magnetic force of the magnetic stripe of the magnetic card 2 by using a built-in core and a coil, converts the change into a change in voltage, amplifies the change in voltage with a built-in amplifier, and amplifies the change in the CPU 6 ( (Shown in FIG. 2).
[0018]
Reference numerals 11 to 13 denote sensors for detecting the magnetic card 2 to be conveyed, which are constituted by photomicrosensors. These sensors 11 to 13 are off when the magnetic card 2 is not detected, but are turned on when the magnetic card 2 is detected. Hereinafter, reference numeral 11 denotes a first sensor, 12 denotes a second sensor, and 13 denotes a third sensor. When the second sensor 12 detects the leading end 2a of the magnetic card 2 and turns on when the magnetic card 2 is taken into the main body 1a and is conveyed in the outward direction F, the magnetic card 2 When the reading of the magnetic information from the magnetic head 5 is started and the third sensor 13 detects the leading end 2a of the magnetic card 2 and turns on, the reading of the magnetic information by the magnetic head 5 is stopped. In the above, the magnetic card reader 10 constitutes the information reading device of the present invention, the magnetic card 2 constitutes the information storage medium of the present invention, and the magnetic head 5 constitutes the reading means of the present invention.
[0019]
FIG. 2 is a block diagram showing an electrical configuration of the magnetic card reader 10. In FIG. 2, reference numeral 6 denotes a CPU that controls each unit of the magnetic card reader 10. The CPU 6 converts the magnetic information read from the magnetic card 2 by the magnetic head 5, that is, the change in the voltage output from the magnetic head 5, from voltage waveform data to jitter data, bit data, and character data as described later. And convert in order. Hereinafter, these data are collectively referred to as read data.
[0020]
Reference numeral 7 denotes a ROM that stores an operation program of the CPU 6 and the like. Reference numeral 8 denotes a RAM that stores, in a readable and writable manner, control data for controlling each unit by the CPU 6, and has a read data storage area Ra (shown in FIG. 3) for storing read data as described later. The CPU 6 stores the read data in the storage area Ra of the RAM 8, and thereafter deletes the stored read data.
[0021]
Reference numeral 9 denotes a reading control unit that adjusts a voltage applied to a coil of the magnetic head 5, a gain value of an amplifier of the magnetic head 5, and the like. The CPU 6 controls the magnetic head 5 by the read control unit 9. Reference numeral 14 denotes a motor control unit that controls the rotation direction and the rotation speed of the motor 15. The CPU 6 drives the motor 15 in the forward direction or the reverse direction by the motor control unit 14 to rotate the roller 4 to convey the magnetic card 2 at an arbitrary speed in the forward direction F or the backward direction B. Reference numeral 16 denotes a card position detection unit which detects the position of the magnetic card 2 based on the switching signals of the sensors 11 to 13 described above. The card position detection unit 16 detects that the magnetic card 2 has been inserted from the insertion slot 3 by a switching signal from the OFF state to the ON state of the insertion detection sensor 17. When the insertion detection sensor 17 is switched in this manner, the CPU 6 drives the motor 15 to rotate in the normal direction, and conveys the magnetic card 2 in the forward direction F by the rotation of the roller 4 and takes it into the main body 1a. Reference numeral 20 denotes a communication unit including an interface for performing mutual communication with the host device 30. The CPU 6 transmits character data and the like to the host device 30 through the communication unit 20.
[0022]
In the above configuration, the CPU 6 constitutes a conversion unit and an erasure unit in the present invention. The RAM 8 constitutes a storage unit in the present invention, and the communication unit 20 constitutes a transmitting unit in the present invention.
[0023]
FIG. 3 is a diagram showing a part of the storage area of the RAM 8. In FIG. 3, Ra is a read data storage area in which read data is stored by the CPU 6. Data storage areas R1 to R5 are assigned to this storage area Ra in advance according to the type of data. R1 is an area for storing voltage waveform data, R2 is an area for storing jitter data, R3 is an area for storing bit data, and R4 is an area for storing character data. R5 is an area for storing other data.
[0024]
FIG. 4 is a diagram for explaining read data. The signal output from the magnetic head 5 to the CPU 6 is an analog signal representing a change in voltage according to a change in magnetic force of the magnetic card 2 as shown in FIG. FIG. 4A shows the output voltage waveform of the magnetic head 5 with time t on the horizontal axis and voltage value V on the vertical axis. The CPU 6 samples this analog signal at predetermined intervals and converts it into digital voltage waveform data as shown in FIG. When converted into voltage waveform data, the CPU 6 detects the peak values (+ V side and -V side) of this data based on the upper and lower threshold values UV and LV, and according to the interval between the detected peak values, As shown in c), the data is converted into jitter data which is pulse waveform data. When converted into jitter data, a narrow interval within a specified range is determined to be “1” and a wide interval is determined to be “0” in accordance with the rising and falling intervals of each pulse of the data. As shown in (1), it is converted into bit data which is logical data of "0" and "1". Finally, the bit data is read according to a predetermined format, and converted into character data as character data as shown in FIG. Each data converted as described above is stored by the CPU 6 in the areas R1 to R4 in the read data storage area Ra of the RAM 8 shown in FIG.
[0025]
FIG. 5 is a diagram for explaining character data converted from bit data. In FIG. 5A, SS (Start Sentinel) is the first control code, ES (End Sentinel) is the last control code, and as shown in FIG. 5B, SS and ES are all “1”. 5 bit data. Also, CD1 to CD # in FIG. 5A are character data one by one, and the maximum number is defined as 104. As shown in FIG. 5B, each of the character data CD1 to CD # has 5-bit bit data representing a character such as an alphanumeric character and VRC (Vertical) which is a parity for each of the character data CD1 to CD #. 1 bit data representing a Redundancy Check). The VRC is defined as “1” when the number of “1” of the 5-bit bit data representing a character is an even number, and is defined as “0” when the number is an odd number. The LRC (Longitudinal Redundancy Check) in FIG. 5A is the parity of the entire data, and is “1” if the number of “1” s of all the bit data is even, and “0” if the number is odd. Stipulated.
[0026]
6 to 10 are flowcharts showing the operation procedure of the magnetic card reader 10. FIG. 6 is an overall flowchart showing processing executed by the CPU 6 based on the program according to the present invention. This program is stored in the ROM 7 (FIG. 2) serving as a recording medium. 7 to 10 are flowcharts showing the details of steps S1, S2, S4, and S5 in FIG. 6, respectively.
[0027]
6, when the magnetic card 2 is inserted into the magnetic card reader 10, the CPU 6 takes the magnetic card 2 into the main body 1a and reads magnetic information from the magnetic card 2 (step S1). The details of this process are shown in FIG. In FIG. 7, when the magnetic card 2 is inserted from the insertion slot 3, the insertion detection sensor 17 is turned on (step S11: YES), and the CPU 6 receives the switching signal and drives the motor 15 to rotate forward. (Step S12). As a result, the magnetic card 2 is taken into the inside 1a of the main body and is conveyed in the outward direction F. Thereafter, when the second sensor 12 detects the leading end 2a of the magnetic card 2 and turns on (step S13: YES), the magnetic head 5 starts reading magnetic information from the magnetic card 2 (step S14). . At this time, the magnetic head 5 detects a change in the magnetic force of the magnetic card 2, converts the change into a voltage change, and outputs it to the CPU 6. When the third sensor 13 detects the leading end 2a of the magnetic card 2 and turns on (step S15: YES), the magnetic head 5 stops reading magnetic information (step S16), and the motor 15 is driven. It stops (step S17). Thus, the transport of the magnetic card 2 in the outward direction F is stopped.
[0028]
When the drive of the motor 15 is stopped, the process proceeds to step S2 in FIG. 6, where the magnetic information read from the magnetic card 2 is converted into read data and stored in the read data storage area Ra of the RAM 8. FIG. 8 shows the details of this processing. In FIG. 8, first, the CPU 6 converts a change in voltage output from the magnetic head 5 into voltage waveform data, and stores the voltage waveform data in the area R1 of the RAM 8 (step S21). Next, the peak value of the voltage waveform data is detected (step S22), the voltage waveform data is converted into jitter data according to the interval between the peak values, and the jitter data is stored in the area R2 of the RAM 8 (step S23). . Then, the jitter data is converted into bit data according to the interval between the rise and fall of the pulse of the jitter data, and the bit data is stored in the area R3 of the RAM 8 (step S24). Subsequently, the bit data is converted into character data according to a predetermined format, and the character data is stored in the area R4 of the RAM 8 (step S25). When the capacity (data length) of these read data is represented by a ratio, when the character data is 1, the bit data is 5 to 10, the jitter data is 10, and the voltage waveform data is 300, for example.
[0029]
When all the read data is stored in the RAM 8 in this manner, the process proceeds to step S3 in FIG. 6, where the communication unit 20 communicates with the host device 30, and transmits the character data stored in the area R4 of the RAM 8 to the host device 30. . Thereby, the host device 30 receives the character data, performs a predetermined process based on the data, and when the predetermined process is completed, transmits a process completion notification to the CPU 6 to notify that the process is completed. Here, an example in which only the character data of the data stored in the RAM 8 is transmitted to the higher-level device 30 is described. However, if necessary, data other than the character data may be transmitted to the higher-level device 30 together. Good. When the communication unit 20 receives the processing completion notification from the host device 30, the CPU 6 terminates the communication with the host device 30 and deletes the read data from the read data storage area Ra of the RAM 8 (step S4).
[0030]
FIG. 9 shows the details of the erasing process. In FIG. 9, of the read information stored in the RAM 8, the information is erased in ascending order of information having a smaller data capacity. That is, character data having the smallest data capacity is erased first (step S31), bit data having the next smallest data capacity is erased (step S32), then jitter data is erased (step S33), and finally Then, the voltage waveform data having the largest data capacity is erased (step S34).
[0031]
When all the read data is erased from the areas R1 to R4 of the RAM 8, the process proceeds to step S5 in FIG. 6, and the magnetic card 2 is returned from the inside 1a of the main body. FIG. 10 shows the details of this processing. 10, first, the CPU 6 drives the motor 15 in the reverse direction (step S41). Thus, the magnetic card 2 is transported in the backward direction B. Then, when the first sensor 11 detects the rear end 2b of the magnetic card 2 and turns on after detecting the front end 2a of the magnetic card 2 (step S42: YES), the motor 15 Is stopped (step S43). Thereby, the conveyance of the magnetic card 2 is stopped, the rear end 2b of the magnetic card 2 projects from the insertion slot 3, and the magnetic card 2 can be removed from the magnetic card reader 10. When the magnetic card 2 is returned as described above, the processing for the magnetic card 2 ends.
[0032]
As described above, in the present embodiment, when erasing the read data stored in the RAM 8, the erasure is performed in order from the character data having the smallest data capacity. For this reason, character data, bit data, and the like, which can be easily decoded, can be quickly erased in the initial stage, and erasing of voltage waveform data having a large data capacity can be started as quickly as possible. Therefore, even if a third party forcibly stops the erasing process on the way, the character data, bit data, and the like have already been erased at that point, and there is no risk of unauthorized acquisition by the third party. On the other hand, if the voltage waveform data cannot be completely erased but partially erased, it is impossible to completely restore the data. Absent. Even if all the voltage waveform data remains in the RAM 8, it is difficult to analyze the data and arrive at the character data due to the large data capacity, thereby reducing the risk of leakage to a third party. Can be.
[0033]
If the character data is identification information unique to a magnetic card such as a credit card number, an account number, a personal identification number, and the like, if such information is illegally acquired by a malicious third party, the card is forged. Although there is a high risk of misuse, the character data is erased first as described above, so that damage due to forgery of the card can be avoided.
[0034]
Further, in performing the series of operations shown in FIGS. 6 to 10, it is not necessary to change the hardware of the existing magnetic card reader 10 and only the program of the ROM 7 needs to be changed. It can be easily realized.
[0035]
FIG. 11 and FIG. 12 are diagrams illustrating another embodiment of the present invention. FIG. 11 is a diagram showing a part of the storage area of the RAM 8, and FIG. 12 is a flowchart showing details of the erasing operation (step S4 in FIG. 6). Note that the read information in the present embodiment is not limited to the above-described voltage waveform data, jitter data, bit data, and character data, but can be any information read from a card. The generalization will be described without specifying the type.
[0036]
In FIG. 11A, the RAM 8 is provided with a storage management area Rm and read data storage areas 1 to 4. The number at the beginning of each area indicates the start address. As shown in FIG. 11B, the storage management area Rm includes an area number for each of the storage areas 1 to 4, a start address indicating the storage position of the read information, and a data length indicating the data capacity of the read information. Recorded as management data. When the read data is stored in the RAM 8, the management data is stored in correspondence with each data. For example, the start address of the storage area 1 is 1000, and the capacity of data stored in this area is 2000 bytes. The start address of the storage area 2 is A000, and the capacity of data stored in this area is 8000 bytes. The start address of the storage area 3 is D000, and the capacity of data stored in this area is 1000 bytes. The start address of the storage area 4 is F000, and the capacity of data stored in this area is 3000 bytes.
[0037]
In the present embodiment, the data stored in the RAM 8 is stored in the order of the storage area 1, the storage area 2, and so on. However, unlike the case of FIG. 3, the storage areas 1 to 4 in FIG. 11 are not fixedly allocated in advance for each type of data, but are determined by the capacity of stored data (data length). It is. Therefore, the values of the addresses A000, D000, and F000 vary depending on the amount of data stored in each storage area. Accordingly, the start address and the data length of the storage management area Rm are also changed every time data is stored. Take different values.
[0038]
Next, the operation of the embodiment of FIG. 11 will be described. Since the entire operation is the same as in FIG. 6, the description thereof will be omitted, and the detailed procedure of step S4 in FIG. 6 will be described with reference to the flowchart in FIG. When the communication with the higher-level device (step S3 in FIG. 6) is completed, the CPU 6 refers to the storage management area Rm of the RAM 8 and determines the erasing order of the data stored in the storage areas 1 to 4 (step S51). This erasing order is determined based on the data length stored in the storage management area Rm, as in the previous embodiment, so that information is erased in ascending order of data capacity. In the example of FIG. 11, since the data stored in the storage area 3 has the smallest capacity, the data is deleted first (step S52). Subsequently, the data in the storage area 1 having the next smallest data capacity is erased (step S53). Thereafter, the data in the storage area 4 is deleted (step S54), and finally, the data in the storage area 2 having the largest data capacity is deleted (step S55).
[0039]
By doing so, data with the smallest data capacity, that is, data that is most easily restored can be preferentially erased. Further, by providing the storage management area Rm, erasure can be performed in ascending order of information having a smaller data capacity without allocating a data storage area in advance as in the case of FIG. If there is data having the same data capacity among the data stored in the storage areas 1 to 4, for example, the data stored in the storage area having the smaller area number may be deleted.
[0040]
In the embodiment described above, after transmitting the character data to the higher-level device 30, the communication with the higher-level device 30 is terminated by receiving a process completion notification from the higher-level device 30, which notifies that the predetermined process has been completed, Although an example in which read data is erased from the RAM 8 has been described, the present invention is not limited to this. For example, after transmitting the character data to the higher-level device 30, the communication with the higher-level device 30 is terminated when a reception completion notification is received from the higher-level device 30 to notify that the reception has been completed, and the read data is transferred from the RAM 8. You may delete it. That is, in the present invention, the read data can be deleted from the RAM 8 at any time after the read data is transmitted to the host device 30. However, if the time for which the read data remains in the RAM 8 becomes longer, the risk of unauthorized acquisition by a third party increases, so it is preferable to delete the read data as soon as possible after transmitting it to the host device.
[0041]
In the above embodiment, the magnetic card 2 is returned after the erasure of the read data from the RAM 8 is completed. However, the present invention is not limited to this. For example, the magnetic card 2 may be returned immediately after erasure of the read data is started. That is, it is sufficient to start erasing the read data before returning the magnetic card 2.
[0042]
Further, in the above embodiment, an example is described in which the magnetic card 2 is used as the information storage medium of the present invention, but the present invention is not limited to this. That is, other than the magnetic card, for example, a medium such as an IC card, a non-contact card, or a magnetic ticket used in a railway or the like may be used.
[0043]
Further, in the above embodiment, the magnetic card reader 10 is taken as an example of the information reading device according to the present invention, but the present invention is not limited to this. For example, a device such as an IC card reader for reading information from an IC card or a card reader / writer for writing information in addition to reading information may be used.
[0044]
【The invention's effect】
According to the present invention, information is erased in ascending order of data capacity. Therefore, even if the data erasing process is forcibly stopped halfway, the information read from the information storage medium is illegally acquired by a third party. Abuse can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic structure of a magnetic card reader.
FIG. 2 is a block diagram illustrating an electrical configuration of a magnetic card reader.
FIG. 3 is a diagram showing a part of a storage area of a RAM.
FIG. 4 is a diagram for explaining read data.
FIG. 5 is a diagram for explaining character data.
FIG. 6 is a flowchart showing an operation procedure of the magnetic card reader.
FIG. 7 is a flowchart showing details of step S1 in FIG. 6;
FIG. 8 is a flowchart showing details of step S2 in FIG. 6;
FIG. 9 is a flowchart showing details of step S4 in FIG. 6;
FIG. 10 is a flowchart showing details of step S5 in FIG. 6;
FIG. 11 is a diagram showing a part of a storage area of a RAM according to another embodiment.
FIG. 12 is a flowchart of an erasing process according to another embodiment.
[Explanation of symbols]
2 Magnetic card 5 Magnetic head 6 CPU
8 RAM
Reference Signs List 10 magnetic card reader 20 communication unit 30 host device Ra read data storage area R1 to R4 data storage area Rm storage management area

Claims (5)

Reading means for reading information from the information storage medium;
Storage means for storing read information read by the reading means,
Transmission means for transmitting the read information stored in the storage means to a higher-level device,
After the transmitting unit transmits the read information to the higher-level device, and an erasing unit that erases the read information stored in the storage unit,
The information reading apparatus, wherein the erasing means erases the information having a smaller data capacity in order from the read information stored in the storage means. Reading means for reading information from the information storage medium;
Storage means for storing read information read by the reading means,
Transmission means for transmitting the read information stored in the storage means to a higher-level device,
After the transmitting unit transmits the read information to the higher-level device, and an erasing unit that erases the read information stored in the storage unit,
The storage means has a storage management area in which a storage position and a data capacity of each read information stored in a plurality of data storage areas are recorded,
The information reading device, wherein the erasing means refers to the storage management area and erases the read information stored in the storage means in order from the information having the smaller data capacity. A magnetic head that detects a change in magnetic force of a magnetic card on which information is magnetically recorded, converts the change into a voltage change, and outputs the change;
The change in the voltage output by the magnetic head is converted into voltage waveform data, the voltage waveform data is converted into jitter data that is pulse waveform data, and the jitter data is logical data of “0” and “1”. Conversion means for converting the bit data into character data which is character data;
Storage means having an area for storing the voltage waveform data, jitter data, bit data and character data,
Transmission means for transmitting data stored in the storage means to a higher-level device,
After the transmitting means transmits the data to a host device, and erasing means for erasing data stored in the storage means,
An information reading apparatus according to claim 1, wherein said erasing means erases data stored in said storage means in the order of character data, bit data, jitter data, and voltage waveform data. The information reading device according to claim 3,
The information reading device, wherein the character data is identification information unique to the magnetic card. A program for an information reading device, which causes an information reading device equipped with a CPU to execute the following processing.
(A) Read processing for reading information from an information storage medium.
(B) a storage process of storing the read information in a storage unit.
(C) transmission processing for transmitting the read information stored in the storage means to a higher-level device;
(D) an erasing process for erasing the read information stored in the storage means in order from the information having the smaller data capacity after transmitting the read information to the host device.

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