Data processing apparatus data erasing method therefor, and program for implementing the method

• US 20060080494A1
• Filed: 09/22/2005
• Published: 04/13/2006
• Est. Priority Date: 09/22/2004
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Mikami, Fumio, Kawaguchi, Tadashi, Hirose, Hideki, Morita, Kei, Atarashi, Eijiro, Haraguchi, Takahiro
• Granted Patent: US 7,730,541 B2
• Time in Patent Office: Days
• US Class Current: 711/4
• CPC Class Codes: G06F 11/2015 Redundant power supplies power supply failure G06F1/30
• CPC Class Codes: G06F 21/608 Secure printing
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: G06K 15/00 Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: G11C 16/22 Safety or protection circuits preventing unauthorised or accidental access to memory cells

Abstract

A data processing apparatus and a data erasing method therefor which are capable of suppressing the capacity of a backup power supply to be used (operating time) and eliminating the disadvantage that a third party steals a look at data to thereby improve security. Data is input, and predetermined processing is performed on the input data. The data is stored in a nonvolatile memory such as a HD. A first voltage supply unit supplies voltage to the memory, and a second voltage unit supplies voltage to the memory when the first voltage supply unit is incapable of supplying voltage to the memory. When the first voltage supply unit becomes incapable of supplying voltage to the memory, the memory is controlled to erase the data stored therein using a selected one of a plurality of erasing processes depending on the status of processing of the data.

Claims

1. A data processing apparatus comprising:

an input unit that inputs data;

a data processing unit that performs predetermined processing on the data input by said input unit;

a nonvolatile storage unit that stores the data on which the processing has been performed by said data processing unit;

a first voltage supply unit that supplies voltage to said storage unit;

a second voltage unit that supplies voltage to said storage unit when said first voltage supply unit is incapable of supplying voltage to said storage unit; and

a control unit responsive to said first voltage supply unit becoming incapable of supplying voltage to said storage unit, for controlling said storage unit to erase the data stored in said storage unit using a selected one of a plurality of erasing processes depending on a status of processing of the data by said data processing unit.

2. A data processing apparatus according to claim 1, comprising an image forming unit that forms an image, and wherein said input unit comprises:

a determining unit that inputs the data received from an external apparatus and determines whether predetermined authentication information is included in the input data; and

an authenticating unit that carries out authentication corresponding to the predetermined authentication information so as to cause said image forming unit to form an image based on the data including the predetermined authentication information.

3. A data processing apparatus according to claim 2, wherein when the predetermined authentication information is included in the data, said control unit carries out a first erasing process in which all of the data stored in said storage unit is erased, and when the predetermined authentication information is not included in the data, said control unit carries out the first erasing process or a second erasing process in which part of the data is erased, depending on the status of processing of the data.

4. A data processing apparatus according to claim 3, wherein the status of processing of the data is indicative of whether said data processing unit has carried out the predetermined processing on all of the data.

5. A data processing apparatus according to claim 2, further comprising a detecting unit that detects an amount of electric power that can be supplied from said second voltage supply unit to said storage unit, and wherein said control unit selects one of the plurality of erasing processes based on the amount of electric power detected by said detecting unit and an amount of the data.

6. A data processing apparatus according to claim 5, further comprising a determining unit that determines an amount of data that can be erased from said storage unit by the amount of electric power detected by said detecting unit, and wherein said control unit selects one of the plurality of erasing processes based on whether the amount of the data is greater than the amount of data that can be erased.

7. A data processing apparatus according to claim 1, further comprising an image forming unit that forms an image based on data generated by the predetermined processing performed on the data by said data processing unit.

8. A data erasing method executed by a data processing apparatus, comprising:

an input step of inputting data;

a data processing step of performing predetermined processing on the data input in said input step;

a storage step of storing the data on which the processing has been performed in said data processing step in a storage unit;

a switching step of switching a source of voltage supply to the storage unit from a first voltage supply unit to a second voltage supply unit when the first voltage supply unit is incapable of supplying voltage to the storage unit; and

an erasing step of erasing the data in response to the switching of the source of voltage supply from the first voltage supply unit to the second voltage supply unit in said switching step, using a selected one of a plurality of erasing processes depending on a status of processing of the data in said data processing step.

9. A data erasing method according to claim 8, comprising an image forming step of forming an image based on data generated by the predetermined processing performed on the data in said data processing step.

10. A data processing apparatus comprising:

an input unit that inputs data;

a data processing unit that performs predetermined processing on the data input by said input unit;

a nonvolatile storage unit that stores the data on which the processing has been performed by said data processing unit;

a first voltage supply unit that supplies voltage to said storage unit;

a second voltage unit that supplies voltage to said storage unit when said first voltage supply unit is incapable of supplying voltage to said storage unit; and

a control unit responsive to said first voltage supply unit becoming incapable of supplying voltage to said storage unit, for causing said storage unit to store a status of processing of the data by said data processing unit, and responsive to resumption of supply of voltage from said first voltage supply unit to said storage unit, for erasing the data using a selected one of a plurality of erasing processes depending on the status of processing of the data.

11. A data processing apparatus according to claim 10, comprising an image forming unit that forms an image, and wherein said input unit comprises:

a determining unit that inputs the data received from an external apparatus and determines whether predetermined authentication information is included in the input data; and

an authenticating unit that carries out authentication corresponding to the predetermined authentication information so as to cause said image forming unit to form an image based on the data including the predetermined authentication information.

12. A data processing apparatus according to claim 11, wherein when the predetermined authentication information is included in the data, said control unit carries out a first erasing process in which all of the data stored in said storage unit is erased, and when the predetermined authentication information is not included in the data, said control unit causes said storage unit to store the status of processing of the data in response to switching of a source of voltage supply from said first voltage supply unit to said second voltage supply unit, and erases the data using a selected one of the plurality of erasing processes depending on the status of processing of the data in response to resumption of voltage supply from said first voltage supply unit to said storage unit.

13. A data processing apparatus according to claim 12, wherein the status of processing of the data is indicative of whether said data processing unit has carried out the predetermined processing on all of the data.

14. A data processing apparatus according to claim 10, further comprising an image forming unit that forms an image based on data generated by the predetermined processing performed on the data by said data processing unit.

15. A data erasing method executed by a data processing apparatus, comprising:

an input step of inputting data;

a data processing step of performing predetermined processing on the data input in said input step;

a storage step of storing the data on which the processing has been performed in said data processing step in a storage unit;

a switching step of switching a source of voltage supply to the storage unit from a first voltage supply unit to a second voltage supply unit when the first voltage supply unit is incapable of supplying voltage to the storage unit; and

an erasing step of causing the storage unit to store a status of processing of the data in response to the switching of the source of voltage supply from the first voltage supply unit to the second voltage supply unit in said switching step, and erasing the data using a selected one of a plurality of erasing processes depending on the status of processing of the data after resumption of voltage supply from the first voltage supply unit to the storage unit.

16. A data erasing method according to claim 15, comprising an image forming step of forming an image based on data generated by the predetermined processing performed on the data in said data processing step.

17. A program for causing a computer to implement a data erasing method executed by a data processing apparatus, comprising:

an input module for inputting data;

a data processing module for performing predetermined processing on the data input by said input module;

a storage module for storing the data on which the processing has been performed by said data processing module in a storage unit;

a switching module for switching a source of voltage supply to the storage unit from a first voltage supply unit to a second voltage supply unit when the first voltage supply unit is incapable of supplying voltage to the storage unit; and

an erasing module for erasing the data in response to the switching of the source of voltage supply from the first voltage supply unit to the second voltage supply unit by said switching module, using a selected one of a plurality of erasing processes depending on a status of processing of the data by said data processing module.

18. A program for causing a computer to implement a data erasing method executed by a data processing apparatus, comprising:

an input module for inputting data;

a data processing module for performing predetermined processing on the data input by said input module;

a storage module for storing the data on which the processing has been performed by said data processing module in a storage unit;

a switching module for switching a source of voltage supply to the storage unit from a first voltage supply unit to a second voltage supply unit when the first voltage supply unit is incapable of supplying voltage to the storage unit; and

an erasing module for causing the storage unit to store a status of processing of the data in response to the switching of the source of voltage supply from the first voltage supply unit to the second voltage supply unit by said switching module, and erasing the data using a selected one of a plurality of erasing processes depending on the status of processing of the data after resumption of voltage supply from the first voltage supply unit to the storage unit.