JP4906663B2 - Data management apparatus and data management method for storage medium - Google Patents

Description

  The present invention relates to a data management apparatus and a data management method for a storage medium that manages data stored in a memory portion of the storage medium.

  The storage medium is a device for storing computer data, and includes a memory portion for storing data and a control portion for controlling the memory portion. As such a storage medium, there is a USB (Universal Serial Bus) memory provided with a rewritable memory. USB memory is widely used because it is a small storage medium that is small and easy to carry. However, when the USB memory is connected to the computer, the data stored in the internal memory can be easily read. Therefore, there is a USB memory for the purpose of data protection (see, for example, Patent Document 1). This USB memory has an internal timer, and when the time set by the user in the USB memory has elapsed, the refresh of the volatile memory is stopped and the data stored in the volatile memory is erased.

According to such a USB memory, the data disappears when the time set by the user elapses. Therefore, even if a third party attaches the USB memory to the computer, the data cannot be referred to as the time elapses. Is protected.
JP 2006-59228 A

  However, the USB memory described above has the following problems. That is, when the time set by the user elapses, the data disappears. For example, even if the user tries to take the USB memory home and refer to the data, if the return time is delayed, the data may be erased. appear. There is also a situation in which data is erased while searching for a USB memory. That is, the conventional USB memory has a problem in usability and is not convenient.

  An object of the present invention is to provide a data management device and a data management method for a storage medium that solve the above-described problems, protect data from a third party, and improve convenience.

In order to solve the above-mentioned problem, the invention of claim 1 is a storage medium comprising a memory part composed of one or more areas for storing data, and a management means for managing the data stored in the area; A setting unit that is provided in the management computer for the storage medium and sets in the management unit a referenceable number of times for limiting the number of references to the area, and when the storage medium is removed from the computer, management means checks whether the reference count for the area has reached the reference number of possible if a reference count for the area is reached the reference number of possible storage, characterized in that resetting the area This is a medium data management device.

According to the first aspect of the invention, when the storage medium is used, the management computer presets in the storage medium a referenceable number of times for limiting the number of references to the area of the storage medium. In this state, by using the storage medium on a computer, when the storage medium has been removed from the computer, if the reference count for the area is reached the reference number of times of the management unit of the storage medium resets this area To do. As a result, the data in this area is erased.

According to a second aspect of the present invention, in the data management device for a storage medium according to the first aspect, when the number of reference times of the area reaches the referenceable number of times, the management unit sends the information to the computer to which the storage medium is connected. An alarm signal indicating an alarm is sent.

According to a third aspect of the present invention, in the data management device for a storage medium according to any one of the first and second aspects, the memory portion continues to store data by refreshing, and the reference count for the area is set to the referenceable count. When it reaches, the management means resets the area by stopping refreshing the area.

According to a fourth aspect of the present invention, in the data management device for a storage medium according to the third aspect , the management unit includes a refresh circuit that refreshes the area, and supplies power to the refresh circuit according to the reference count. It is characterized by management.

The invention according to claim 5 is a data management method for a storage medium that includes a memory portion including one or more areas for storing data, and manages the data stored in the area, wherein the number of times of reference to the area is determined. The referenceable number of times to be limited is set in the storage medium, and when the storage medium is removed from the computer, it is checked whether or not the reference number of times for the area has reached the referenceable number of times. If you are us referenceable count, it resets the area, a data management method of a storage medium, characterized in that.

According to the inventions of claims 1 and 5 , since the data stored in the storage medium is erased by limiting the number of references to the storage medium, for example, forgetting the USB memory, for example, Data is not erased over time, it is easy to use and convenience can be improved. Further, when the memory portion is composed of a plurality of areas, it is possible to deal with various data such as data to be deleted by one reference or data to be left.

Moreover, when the storage medium is removed from the computer, in order to check whether or not the reference count for the area has reached the reference count, the stored data is immediately stored when the reference count reaches the reference count. Since it is not erased, data can be saved.

According to the second aspect of the present invention, when the reference count reaches the reference possible count, a warning signal is sent to the computer using the storage medium, so that the data can be saved.

According to the invention of claim 3 , by using the memory portion that continues to store data by refresh, the refresh is stopped and the area is reset, so that the data in the area can be easily erased.

According to the fourth aspect of the invention, since the refresh is stopped and the area is reset by managing the DC power supplied to the refresh circuit that performs the refresh, the data in the area can be erased more easily.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
A storage medium data management apparatus according to this embodiment will be described with reference to FIGS. The storage medium data management apparatus according to this embodiment includes a personal computer (PC) 10 and a USB memory 20.

  The personal computer 10 is a management computer that performs settings for the USB memory 20, and includes a processing unit 12, a storage unit 13, a display unit 14, an input unit 15, and a USB interface ( I / F) 16. The input unit 15 is a device such as a keyboard or a mouse, and data, various instructions, and the like are input to the input unit 15. The display unit 14 is a display device such as an LCD (liquid crystal display), and displays data input to the input unit 15 under the control of the processing unit 12. The USB interface 16 is an interface for connecting the USB memory 20, and inputs / outputs data to / from the USB memory 20 and supplies DC power to the USB memory 20 under the control of the processing unit 12. The storage unit 13 stores various programs for the personal computer 10. Further, the data input to the input unit 15 is temporarily stored under the control of the processing unit 12.

  The processing unit 12 executes various programs stored in the storage unit 13. The program executed by the processing unit 12 includes a setting process for the USB memory 20, and this setting process is shown in FIG. When a setting instruction for the USB memory 20 is input to the input unit 15, the processing unit 12 selects the first area number (step S1). The area is formed in a memory portion for storing data in the USB memory 20, and n areas are provided in the memory portion. In order to identify each area, each area is given an area number as identification information.

  When step S1 ends, the processing unit 12 instructs the input of the referenceable number of times for the first area (step S2). Accordingly, the processing unit 12 controls the display unit 14 to display an input screen for the referenceable number of times. The area of the USB memory 20 is a computer including the personal computer 10, and the number of times of reference from a computer to which the USB memory 20 is connected (hereinafter referred to as “connected computer”) can be limited. If the referenceable number of times is not set for the area of the USB memory 20, for example, “0” is input to the input unit 15 as a predetermined number.

  After step S2, the processing unit 12 waits for the referenceable number of times (step S3). When the processing unit 12 receives the reference possible number from the input unit 15 in step S3, the processing unit 12 stores the received reference possible number together with the area number in the storage unit 13 (step S4). Thereafter, the processing unit 12 determines whether there is an unselected area number (step S5). If there is an unselected area number, the processing unit 12 selects the next area number (step S6), and returns the process to step S2. In this way, by repeating the process, the referenceable number of times is set for all the areas of the USB memory 20.

  On the other hand, if there is no unselected area number in step S5, the processing unit 12 reads all the referenceable counts and area numbers from the storage unit 13 (step S7). Then, the processing unit 12 controls the USB interface 16 to transmit the readable reference times and the area number to the USB memory 20 (step S8), and ends the setting process.

  When data in the USB memory 20 is used according to an instruction from the input unit 15, the processing unit 12 refers to the USB memory 20 by controlling the USB interface 16. The reference to the USB memory 20 is the same for a general personal computer. Further, when receiving various signals from the USB memory 20, the processing unit 12 controls the display unit 14 to perform display based on the signals. For example, when an error signal is received from the USB memory 20, the processing unit 12 displays a non-permission of appending to the area of the USB memory 20 on the display unit 14. Such a display is the same as that of a general personal computer. In the following, each part of the personal computer 10 is also cited for a connection computer that is a general computer.

The USB memory 20 includes a USB interface (I / F) 21, a controller 22, an internal power supply circuit 23, RAMs (Random Access Memory) 24 _{1 to} 24 _n, and refresh circuits 25 _{1 to} 25 _n .

  The USB interface 21 is connected to, for example, the USB interface 16 of the personal computer 10 as a connection computer, transmits / receives data to / from the USB interface 16 and receives a DC power supply. When the USB interface 21 receives supply of DC power from the USB interface 16 of the connected computer, the USB interface 21 sends this DC power to the internal power supply circuit 23.

  When the USB interface 21 receives the referenceable number of times and the area number from the USB interface 16 of the personal computer 10, it sends them to the controller 22. When the USB interface 21 receives data (hereinafter referred to as “stored data”) to be stored in the USB memory 20 from the USB interface 16 of the personal computer 10, the USB interface 21 sends the stored data to the designated RAM.

  The USB interface 21 sends the area number of the referenced area to the controller 22 as a reference signal when data is referred to an area designated by the personal computer 10 as a connected computer.

When the internal power supply circuit 23 receives the DC power supply from the USB interface 21, the internal power supply circuit 23 converts the DC power supply into a DC power supply having a predetermined voltage, and applies the DC power supply to the controller 22 and the refresh circuits 25 _{1 to} 25 _n . The USB interface 21 includes a chargeable / dischargeable battery 23A. The internal power supply circuit 23 charges the battery 23 </ b> A with the DC power received from the USB interface 21. Thereafter, when the supply of the DC power supply from the USB interface 21 is stopped, the internal power supply circuit 23 generates a DC power supply of a predetermined voltage using the DC power supply of the battery 23A, and this DC power supply is used as the controller 22 and the refresh circuit 25 _1. Add to ~ 25 _n .

The RAMs 24 _{1 to} 24 _n are readable / writable volatile memories such as DRAM (Dynamic Random Access Memory). The RAMs 24 _{1 to} 24 _n are obtained by dividing the memory portion of the USB memory 20 into n parts, or an aggregate of n RAMs. RAM 24 ₁ to 24 _n is an area for storing data, respectively, to identify the RAM 24 ₁ to 24 _n, the RAM 24 ₁ to 24 _n areas are numbered as identification information.

The refresh circuits 25 _{1 to} 25 _n are each operated by a DC power supply from the internal power supply circuit 23. Refresh circuit ₂₅ 1 to 25 _n is controls the RAM 24 ₁ to 24 _n, respectively, since all are the same, describes refresh circuit 25 _1, the description thereof is omitted refresh circuit ₂₅ 2 to 25 _n. Refresh circuit 25 ₁ is to control the RAM 24 _1. To retain data written in RAM 24 _1, for the RAM 24 _1, it is necessary to re-write (refresh) at regular time intervals, refresh circuit 25 ₁ performs the refresh against RAM 24 _1. At this time, the refresh circuit 25 _1, while the internal power supply circuit 23 is supplied with a DC power source that always refresh for RAM 24 _1, the control to hold the data. Supply of direct-current power from the internal power supply circuit 23 for the refresh circuit 25 ₁ is controlled by a controller 22.

The controller 22 includes a memory (not shown) for storing data therein, and controls the refresh circuits 25 _{1 to} 25 _n based on setting data stored in the memory. When the controller 22 receives the referenceable number of times and the area number from the USB interface 21, it creates setting data using these and stores the setting data in the memory.

The setting data stored in the controller 22 is shown in FIG. In the setting data in FIG. 4, the reference possible times of the RAMs 24 _{1 to} 24 _n received from the personal computer 10 are recorded. The RAMs 24 _{1 to} 24 _n are identified by area numbers. In this embodiment, No. 1 to No. n are used as area numbers, and RAMs 24 _{1 to} 24 _n are represented by “No. 1 area” to “No. n area”. In the setting data, the number of times the RAMs 24 _{1 to} 24 _n are referred from the computer to which the USB memory 20 is connected is recorded in the reference number column. When “0”, which is a number indicating that the referenceable number of times is not set, is received from the setting personal computer 10, this value is recorded in the setting data, and the reference number is not limited. The controller 22 is the area number received from the USB interface 21, and updates the reference count of the corresponding area every time an area number referred to by the connected computer, that is, a reference signal is received.

  The controller 22 does not permit additional writing to the RAM for which the referenceable number of times is set. If data is written, the controller 22 sends an error signal indicating an error to the connected computer via the USB interface 21. Note that such control by the controller 22 may be performed by the USB interface 21.

The controller 22 performs management processing for managing data stored in the RAMs 24 _{1 to} 24 _n by connecting the USB memory 20. When the management process is started, as shown in FIG. 5, the controller 22 checks the supply state of the DC power from the connected computer (step S21), and determines whether this DC power is cut off (step S22). If the DC power from the connected computer is not cut off, the controller 22 waits for an area number from the USB interface 21, that is, a reference signal (step S23).

  When a reference signal is received for a predetermined time after step S23 (step S24), the controller 22 updates the corresponding reference count in the setting data (FIG. 4) (step S25). Thereafter, the controller 22 checks the reference count of the setting data (FIG. 4) (step S26), and determines whether or not the reference count is a referable count (step S27). If the reference count is the reference possible count, the controller 22 sends a warning signal to the connected computer via the USB interface 21 (step S28). This warning signal is for urging the saving of data stored in the USB memory 20 because the RAM of the corresponding area number has reached the referenceable number of times. When step S28 ends, the controller 22 returns the process to step S21. If the reference signal is not received during the predetermined time in step S24, or if the reference count has not reached the referable count in step S27, the controller 22 returns the process to step S21.

  On the other hand, if it is determined in step S22 that the DC power from the connected computer is cut off, the controller 22 uses the setting data (FIG. 4) to check the area number where the reference count reaches the reference possible count (step S22). S29). If there is an area number that has reached the referenceable number in step S29 (step S30), the controller 22 extracts the first area number from the setting data (FIG. 4) (step S31). Thereafter, the controller 22 issues an instruction to turn off the DC power supply from the internal power supply circuit 23 to the refresh circuit that controls the RAM of the extracted area number (step S32). As a result, the refresh circuit is powered off, resets the RAM, and erases data.

  Thereafter, the controller 22 determines whether or not the power-off in step S32 is the first (step S33). If it is the first power-off, the controller 22 returns the process to step S32. As a result, the controller 22 turns off the power to the corresponding RAM twice, resets the RAM, and securely erases the data.

  If the controller 22 determines that it is not the first power-off in step S33, it determines whether there is an unextracted area number (step S34). If there is an unextracted area number, the controller 22 extracts the next area number from the setting data (FIG. 4) (step S35), and returns the process to step S32.

  On the other hand, if there is no area number in step S30, or if there is no unextracted area number in step S34, the controller 22 ends the management process.

  Next, a data management method using the storage medium data management apparatus according to this embodiment will be described.

  When the USB memory 20 is connected to the management personal computer 10 and a setting instruction for the USB memory 20 is input to the input unit 15 of the personal computer 10, the personal computer 10 performs setting processing and can be referred to the RAM. And the area number are transmitted to the USB memory 20. When the USB interface 21 of the USB memory 20 receives the reference count and the area number, the USB interface 21 sends them to the controller 22. The controller 22 creates setting data based on the referenceable number of times and the area number, and stores this setting data in a memory (not shown).

When the USB memory 20 is used in such a state, the controller 22 of the USB memory 20 is set every time data is referred to an arbitrary RAM in the RAMs 24 _{1 to} 24 _n in steps S21 to S25 of the management process. Data (FIG. 4) is updated. Then, if there is a RAM in which the reference count of the setting data (FIG. 4) has reached the referable count in steps S26 to S28 of the management process, the controller 22 transmits a warning signal corresponding to this RAM to the connected computer. When the processing unit 12 of the connected computer receives the warning signal, the processing unit 12 controls the display unit 14 to display a message that prompts the user to save the data stored in the USB memory 20.

  After that, when the USB memory 20 is removed from the connected computer and the DC power supply from the connected computer is cut off, the controller 22 refreshes the RAM whose reference count has reached the reference count by steps S29 to S35 of the management process. The circuit is controlled to cut off the supply of DC power from the internal power supply circuit 23 to the refresh circuit. As a result, the refresh circuit does not refresh the RAM, so the RAM is reset and the data is erased. In particular, the controller 22 resets the RAM twice in steps S32 and S33 of the management process, and securely erases the data.

Thus, by this embodiment, the RAM 24 ₁ area in the memory portion of USB memory 20 as to 24 _n provided, since erased by limiting the number of references for the RAM 24 ₁ to 24 _n, respectively, the information from a third party Can be protected. Moreover, since the data is erased by limiting the number of times of reference, it is easy to use without causing the situation that the data is erased while searching forgetting the USB memory as in the past. It is possible to improve convenience. Further, according to this embodiment, the refresh circuits 25 _{1 to} 25 _n operate with the direct current power source of the battery 23A. Therefore, if the USB memory 20 is not connected to the computer for a long time, the battery 23A is cut off and the refresh circuit 25 ₁ since refresh according to 25 _n is not performed, the protection of data when you lose USB memory 20, it is possible to make them secure. In addition, according to this embodiment, since the data is deleted when the USB memory 20 is extracted from the connected computer in the area where the reference count reaches the reference possible count, time for saving the data can be given. In addition, according to this embodiment, the memory portion of the USB memory 20 is formed with a plurality of areas, so various data such as data to be deleted with one reference or data to be retained can be handled. Is possible.

(Embodiment 2)
In the previous embodiment, a plurality of RAMs 24 _{1 to} 24 _n are used as the memory portion. However, in this embodiment, as shown in FIG. 6, one RAM 24A is used as the memory portion, and one refresh is accompanied accordingly. Circuit 25A is used. In this embodiment, components that are the same as or the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

  According to this embodiment, the setting process performed by the personal computer 10 is simplified as shown in FIG. When a setting instruction for the USB memory 20 is input to the input unit 15, the processing unit 12 instructs the RAM 24A to input a referenceable number of times (step S61). As a result, the processing unit 12 controls the display unit 14 to display an input screen for the referenceable number of times. For the RAM 24A, the number of times data is referred to from the connected computer can be limited. In step S61, an instruction to input this number is issued. As in the first embodiment, when the referenceable number of times is not set for the RAM 24A, for example, “0” number is input to the input unit 15 as a predetermined number.

  After step S61, the processing unit 12 waits for the referenceable number of times (step S62). When the processing unit 12 receives the referenceable number of times from the input unit 15 in step S62, the processing unit 12 controls the USB interface 16 to transmit the received referenceable number of times to the USB memory 20 (step S63), and ends the setting process. .

  The USB interface 21 sends a reference signal to the controller 22 when data is referenced to the RAM 24A. When receiving the reference signal, the controller 22 creates simplified setting data shown in FIG. The setting data in FIG. 8 records the number of times the RAM 24A can be referenced and the number of times the RAM 24A is referenced, received from the personal computer 10.

  The controller 22 performs the management process shown in FIG. When the management process is started, the controller 22 checks the supply state of the DC power from the connected computer (step S81), and determines whether this DC power is cut off (step S82). If the DC power from the connected computer is not cut off, the controller 22 waits for a reference number from the USB interface 21 (step S83).

  Thereafter, when a reference signal is received during a predetermined time (step S84), the controller 22 updates the reference count of the setting data (FIG. 8) (step S85). Thereafter, the controller 22 checks the reference count of the setting data (FIG. 8) (step S86), and determines whether or not the reference count is a referable count (step S87). If the reference count is the reference possible count, the controller 22 sends a warning signal to the connected computer via the USB interface 21 (step S88).

  When step S88 ends, the controller 22 waits for the DC power supply from the connected computer to be cut off (step S89). When the DC power supply of the connected computer is cut off in step S89, the controller 22 instructs the refresh circuit 25A that controls the RAM 24A to cut off the DC power supply from the internal power supply circuit 23 (step S90). When the refresh circuit is powered off, the controller 22 resets the RAM 24A and erases the data.

  Thereafter, the controller 22 determines whether or not the power-off in step S90 is the first (step S91). If it is the first power-off, the controller 22 returns the process to step S90. As a result, the controller 22 turns off the power to the RAM 24A twice, resets the RAM 24A, and securely erases the data.

  If the controller 22 determines that the power is turned off in step S82, or if it is determined that the power is not turned off for the first time in step S91, the controller 22 ends the management process.

  Next, a data management method using the storage medium data management apparatus according to this embodiment will be described.

  When the USB memory 20 is connected to the personal computer 10 and a setting instruction for the USB memory 20 is input to the input unit 15 of the personal computer 10, the personal computer 10 performs setting processing and setting data in the RAM 24A (FIG. 8). And the setting data is stored in a memory (not shown).

  When the USB memory 20 is used in such a state, the controller 22 of the USB memory 20 updates the setting data (FIG. 8) every time data is referred to the RAM 24A through steps S81 to S85 of the management process. Then, when the reference number of the setting data (FIG. 8) in the RAM 24A reaches the referenceable number in steps S86 to S88 of the management process, the controller 22 transmits a warning signal in the RAM 24A to the connected computer. When the connected computer receives the warning signal, the connected computer displays a message prompting the user to save the data stored in the USB memory 20 as in the first embodiment.

  Thereafter, when the USB memory 20 is removed from the connected computer and the DC power supply from the connected computer is cut off, the controller 22 controls the refresh circuit 25A in steps S89 to S91 of the management process to control the refresh circuit 25A. The DC power supply from the internal power supply circuit 23 is cut off. As a result, the refresh circuit 25A does not refresh the RAM 24A, so the RAM 24A is reset and data is erased. In particular, the controller 22 resets the RAM 24A twice in accordance with steps S90 and S91 of the management process, thereby reliably erasing data.

  Thus, according to this embodiment, since the memory portion is made into one area, each process can be simplified. In particular, the controller 22 of the USB memory 20 only has to control one refresh circuit 25A. The burden on the controller 22 can be reduced. In addition, the RAM 24A has the same effect as that of the first embodiment.

  As mentioned above, although each embodiment of this invention has been described in detail, the specific configuration is not limited to these embodiments, and even if there is a design change or the like without departing from the scope of this invention. Are included in the present invention. For example, in each embodiment, a DRAM is used for the memory portion of the USB memory 20, but the technical idea that the data stored in the USB memory 20 is erased depending on whether or not the reference count has reached the set count is other than that. It is also applicable to memory.

1 is a perspective view illustrating an external appearance of a personal computer and a USB memory according to Embodiment 1. FIG. It is a block diagram showing the structure of the personal computer and USB memory of FIG. 3 is a flowchart illustrating a personal computer setting process according to the first embodiment. 6 is a diagram illustrating an example of setting data stored in a USB memory controller according to Embodiment 1. FIG. 3 is a flowchart illustrating USB memory management processing according to the first embodiment. FIG. 6 is a configuration diagram illustrating a structure of a personal computer and a USB memory according to a second embodiment. 10 is a flowchart illustrating a personal computer setting process according to the second embodiment. 6 is a diagram illustrating an example of setting data stored in a USB memory controller according to Embodiment 2. FIG. 12 is a flowchart illustrating USB memory management processing according to the second embodiment.

Explanation of symbols

10 Personal computer (management computer)
11 bus 12 processing unit (setting means)
13 storage unit 14 display unit 15 input unit (setting means)
16 USB interface (setting means)
20 USB memory (storage medium)
21 USB interface 22 Controller (management means)
23 Internal power supply circuit 24 _{1 to} 24 _n , 24A RAM (area)
25 _{1 to} 25 _n , 25A refresh circuit (management means)

Claims (5)

A storage medium comprising a memory portion composed of one or more areas for storing data, and management means for managing the data stored in the areas;
A setting unit provided in the computer for managing the storage medium, setting a reference possible number of times for limiting the number of references to the area in the management unit;
With
When the storage medium has been removed from the computer, the management unit checks whether the reference count for the area has reached the reference number of possible if the reference count for the area is reached the reference number of possible the data management system of the storage medium characterized by resetting the area. 2. The storage according to claim 1 , wherein when the number of reference times of the area reaches the referenceable number of times, the management unit sends an alarm signal indicating an alarm to the computer to which the storage medium is connected. Media data management device. The memory portion continues to store data by refreshing, and when the reference count for the area reaches the reference possible count, the management unit resets the area by stopping refreshing the area. The data management device for a storage medium according to claim 1 or 2 . 4. The data management apparatus for a storage medium according to claim 3 , wherein the management unit includes a refresh circuit that refreshes the area, and manages power supply to the refresh circuit according to the reference count. A data management method for a storage medium that includes a memory portion including one or more areas for storing data, and manages data stored in the areas,
A reference possible number of times for limiting the number of references to the area is set in the storage medium,
When the storage medium has been removed from the computer checks whether the reference count for the area has reached the reference number of possible if a reference count for the area is reached the reference number of possible the area Reset,
A data management method for a storage medium.

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