U.S. patent application number 12/726131 was filed with the patent office on 2010-07-08 for image forming apparatus and method for erasing image data.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Mitsuhiro KINOSHITA.
Application Number | 20100171974 12/726131 |
Document ID | / |
Family ID | 38876302 |
Filed Date | 2010-07-08 |
United States Patent
Application |
20100171974 |
Kind Code |
A1 |
KINOSHITA; Mitsuhiro |
July 8, 2010 |
IMAGE FORMING APPARATUS AND METHOD FOR ERASING IMAGE DATA
Abstract
An image forming apparatus includes an image data input unit
configured to take in image data, an image data memory unit
configured to save image data, a data output unit configured to
output the image data in a specific format, and an image data
erasing unit configured to erase the image data saved in the image
memory unit after output processing by the data output unit is
completed. The image data erasing unit requests the user to make a
selection as to whether or not an erasing manipulation for image
data as an erasure object is executed, and erases the image data by
an erasing method at a different security level according to the
selection in response to a selection request.
Inventors: |
KINOSHITA; Mitsuhiro;
(Shizuoka-ken, JP) |
Correspondence
Address: |
PATTERSON & SHERIDAN, L.L.P.
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON
TX
77056
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Tokyo
JP
TOSHIBA TEC KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
38876302 |
Appl. No.: |
12/726131 |
Filed: |
March 17, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11421747 |
Jun 1, 2006 |
7710591 |
|
|
12726131 |
|
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Current U.S.
Class: |
358/1.14 ;
358/1.16 |
Current CPC
Class: |
H04N 1/4406 20130101;
H04N 2201/3295 20130101; H04N 1/32358 20130101; H04N 1/444
20130101 |
Class at
Publication: |
358/1.14 ;
358/1.16 |
International
Class: |
G06K 15/02 20060101
G06K015/02 |
Claims
1. An image forming apparatus, comprising: an image data input unit
configured to take in image data; an image data memory configured
to save image data inputted through the image data input unit; a
data output unit configured to output the image data saved in the
image data memory in a specific format; a display configured to
display a selection screen which prompts a user to input a
selection as to whether to erase the image data or not after the
image data is outputted by the data output unit; and a controller
configured to erase an address where the image data is stored in
the image data memory if neither erasing nor rejection to erase the
image data is selected within a grace time.
2. The image forming apparatus according to claim 1, wherein the
controller configured to write random data over the image data if
erasing the image data is selected.
3. The image forming apparatus according to claim 2, wherein the
controller configured to erase the address alone if rejection to
erase the image data is selected.
4. The image forming apparatus according to claim 3, wherein the
controller configured to write random data over the image data and
erase the address if erasing the image data is selected.
5. The image forming apparatus according to claim 3, further
comprising a timer configured to set the grace time during which
the user is able to respond to the selection screen by the
display.
6. The image forming apparatus according to claim 2, wherein the
display configured to display other selection screen which prompts
the user to select a number of overwriting times of the random data
if overwriting the image data is selected.
7. The image forming apparatus according to claim 2, wherein the
controller configured to neither write random data over the image
data nor erase the address if rejection to erase the image data is
selected.
8. The image forming apparatus according to claim 1, wherein the
image data input unit includes any of: an optical document read
unit configured to read a document as image data; a facsimile data
reception unit configured to receive facsimile data via a telephone
line; and a LAN control unit configured to receive print data via a
LAN from a terminal linked to the LAN.
9. A method for erasing image data for erasing image data related
to a specific job from a memory device which is provided to an
image forming apparatus to save image data after the job is
completed, comprising: saving the image data in the memory device;
outputting the image data saved in the memory device in a specific
format; displaying a selection screen which prompts a user to input
a selection as to whether to erase the image data or not after the
image data is outputted; and erasing an address where the image
data is stored in the memory device if neither erasing nor
rejection to erase the image data is selected within a grace
time.
10. The method according to claim 9, further comprising: writing
random data over the image data if erasing the image data is
selected.
11. The method according to claim 10, further comprising: erasing
the address alone if rejection to erase the image data is
selected.
12. The method according to claim 11, further comprising:
performing to write random data over the image data and erase the
address if erasing the image data is selected.
13. The method according to claim 11, further comprising: setting
the grace time during which the user is able to respond to the
selection screen.
14. The method according to claim 10, further comprising:
displaying other selection screen which prompts the user to select
a number of overwriting times of the random data if overwriting the
image data is selected.
15. The method according to claim 10, further comprising: operating
neither to write random data over the image data nor to erase the
address if rejection to erase the image data is selected.
16. The method according to claim 9, wherein the memory device
being operable to receive the image data from any of: an optical
document read unit configured to read a document as image data; a
facsimile data reception unit configured to receive facsimile data
via a telephone line; and a LAN control unit configured to receive
print data via a LAN from a terminal linked to the LAN.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image forming apparatus,
such as a coping machine, a printer, a scanner, a facsimile
machine, and a multifunction peripheral furnished with some of the
capabilities of these machines, and to a method for erasing image
data to erase image data related to a specific job, such as a print
job, from a memory device provided to the image forming apparatus
to save the image data after the job is completed.
[0003] 2. Description of the Related Art
[0004] In a case where a copy of a certain document is made using a
multifunction peripheral (MFP) as a copying machine, the document
is first read by the scanner. Image data of the document is thus
obtained. The image data is saved in the hard disc drive (HDD)
provided as a memory device. The image data is then read out from
the HDD and restored to an image again, and this image is printed
on a sheet of paper. Even when a print job is suspended by a
trouble, such as paper jamming, the configuration as above enables
printing to be resumed using the image data saved in the HDD and
thereby eliminates the need to scan the document again after the
trouble is removed. In addition, a print job, such assorting,
multiple printing, and double face printing, can be executed
smoothly. When the print job ends, the image data saved in the HDD
is erased so that the document will no longer be reproduced.
[0005] A print job by the printer, a print job of reception data by
a facsimile machine, and a data transmission job by a facsimile
machine can be executed in the same manner. For example, for a
print job that uses the MFP as a printer, print data written in a
page description language is first transmitted to the MFP from a
personal computer or the like. The print data is then subjected to
bit map conversion page by page by a raster image processor (RIP)
provided to the MFP. Page data is thus generated. The page data is
temporarily saved in the HDD. The page data is then read out from
the HDD and restored to an image, and this image is printed on a
sheet of paper. After the print job ends, the page data saved in
the HDD is erased so that the page data will no longer be
reproduced.
[0006] Generally, the HDD includes a data save region and a file
management region. In an HDD provided to the image forming
apparatus, image data (or page data) is saved in the data save
region. Also, information (so-called FAT (File Allocation Table)
information) to know at which address in the data save region the
image data is saved is stored in the file management region.
[0007] One method for erasing image data saved in the HDD is a
method for erasing the FAT information related to the image data
from the file management region. According to this data erasing
method, the image data itself is not erased from the data save
region. However, once the FAT information is erased, the location
at which the corresponding image data is present becomes unknown,
which inhibits an access to the image data. Accordingly, the image
data is assumed to have been erased.
[0008] This data erasing method has an advantage that loads on the
processor that performs operation control of the image forming
apparatus and data processing can be reduced. According to this
data erasing method, however, it is not impossible to reproduce
image data because the image data itself is not erased. Should an
evil-minded third party obtain an HDD in which highly confidential
documents or the like are saved in the form of image data, there is
a risk that the documents are restored.
[0009] Given these circumstances, as another data erasing method,
there is a method for erasing image data by writing random data
over the image data saved in the HDD several times. According to
this method, however, it takes a long time to erase data. Also, the
performance is deteriorated because, for example, a new job is
limited while the data is being erased. Further, there is a problem
that the life of the HDD is shortened as the number of accesses to
the HDD increases.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide an
easy-to-manipulate image forming apparatus furnished with a high
security function against leakage of image data and yet achieving
an excellent performance and a method for erasing image data from a
memory device provided to this image forming apparatus.
[0011] An image forming apparatus of the present invention
includes: an image data input unit configured to take in image
data; an image data memory unit configured to save image data
inputted from the image data input unit; a data output unit
configured to output the image data saved in the image data memory
unit in a specific format; and an image data erasing unit
configured to erase the image data saved in the image data memory
unit after output processing by the data output unit is completed,
wherein the image data erasing unit includes: an erasing selection
unit configured to request a user to make a selection as to whether
or not an erasing manipulation for image data as an erasure object
is executed; and a data erasing unit configured to erase the image
data by an erasing method at a different security level according
to the selection of the user in response to a selection request
from the erasing selection unit.
[0012] Also, an image forming apparatus of the invention includes:
image data input means for taking in image data according to a
specific job specified by a user; memory means for saving taken-in
image data; data output means for outputting the image data in a
specific format according to the job; erasing selection means for
requesting the user to make a selection as to whether or not the
image data is erased from the memory means after an output of the
image data is completed; and data erasing means for erasing the
image data by an erasing method at a different security level
according to the selection of the user.
[0013] A method for erasing image data of the present invention is
a method for erasing image data related to a specific job from a
memory device which is provided to an image forming apparatus to
save image data after the job is completed, including the steps of:
taking in image data; saving the image data in the memory device;
outputting the image data in a specific format; requesting a user
to make a selection as to whether or not the image data is erased
from the memory device after an output of the image data is
completed; and erasing the image data by an erasing method at a
different security level according to the selection of the
user.
[0014] According to the image forming apparatus and the method for
erasing image data of the present invention, it is possible to make
it extremely difficult to reproduce image data corresponding to a
document or the like that the user judges as being highly
confidential; moreover, it is possible to maintain performance and
the ease of manipulation in a satisfactory manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a view showing the system configuration of an
image forming apparatus according to one embodiment of the present
invention;
[0016] FIG. 2 is a view showing an example of a screen display on a
liquid crystal display unit when a copy job is completed;
[0017] FIG. 3 is a view showing an example of a relation between a
grace time and a job set in an erasing timer set unit; and
[0018] FIG. 4 is a flowchart detailing a copy job by the image
forming apparatus.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] Hereinafter, embodiments of the present invention will be
described in detail, with reference to the drawings.
[0020] FIG. 1 is a view showing the system configuration of an
image forming apparatus according to one embodiment of the present
invention. An image forming apparatus 100 is a multifunction
peripheral (MFP) and is furnished with capabilities of a copying
machine, a printer, a scanner, and a facsimile machine.
[0021] The image forming apparatus 100 includes a central
processing unit (CPU) 10 that governs operation control of the
image forming apparatus 100 and data processing, a ROM 12 in which
program data needed for the operation control of the image forming
apparatus 100 and data processing is stored, a RAM 14 that
temporarily stores control information or the like while the image
forming apparatus 100 is operating, a key input unit 16 having
various buttons used to manipulate the image forming apparatus 100,
and a liquid crystal display unit 18 that displays manipulation
information responding to manipulations on the key input unit 16
and ongoing job information. The liquid crystal display unit 18 is
furnished with a touch panel capability.
[0022] The image forming apparatus 100 also includes a scanner unit
20 provided as a document read unit that reads a copy document or a
facsimile transmission document, a print unit 22 that prints the
copy document or reception data on a sheet of paper, a
coding/decoding unit 24 that converts image data into encoded data
at the time of facsimile transmission and decodes received encoded
data into image data, a line control unit 26 that controls a
telephone line for a facsimile communication, a modem 28 that
modulates encoded data from the coding/decoding unit 24 to output
the resulting signal to the line control unit 26 and demodulates a
modulated signal received at the line control unit 26, a LAN
control unit 30 that receives print data transmitted from a
personal computer (PC) 38 linked to the image forming apparatus 100
via a LAN, and an image data memory unit 32 that saves image data
or the like handled in the image forming apparatus 100.
[0023] A hard disc drive (HDD) is suitable for the image data
memory unit 32. Hereinafter, assume that the image data memory unit
32 comprises an HDD, and is therefore denoted as "HDD 32".
[0024] The image forming apparatus 100 further includes an image
data erasing unit 34 that erases image data saved in the HDD 32,
and an erasing timer set unit 36 that sets timing to erase data in
the HDD 32 by the image data erasing unit 34.
[0025] The image data erasing unit 34 includes an erasing selection
unit 34a that requests the user to select a single method among
plural methods for erasing image data related to a specific job,
such as a copy job, from the HDD 32 when this job ends. The image
data erasing unit 34 also includes a data erasing unit 34b that
erases image data from the HDD 32 according to the single erasing
method selected by the user. To be more concrete, the erasing
selection unit 34a includes a memory device, such as a ROM, having
stored a program to exert capabilities specified below, and a CPU
that executes such a program.
[0026] The erasing selection unit 34a causes the liquid crystal
display unit 18 to display erasing methods of image data. One
example is shown in FIG. 2. A signal informing that the copy job is
completed is sent from the CPU 10 to the erasing selection unit
34a. The erasing selection unit 34a then causes the liquid crystal
display unit 18 to display a message shown in FIG. 2. When the user
touches the icon of "YES" for an inquiry, "Erase data?", shown in
FIG. 2, "YES" is selected, and when the user touches the icon of
"NO", "NO" is selected. As will be described below, in a case where
the icon of "NO" is selected, the image data is erased anyway. FIG.
2 therefore shows two erasing methods.
[0027] For example, in a case where a copy job for highly
confidential documents is executed, the user selects the icon of
"YES". In this case, meaningless random data, such as "00" and
"FF", is written over the image data related to this copy job by
the data erasing unit 34b, and further, the FAT information of the
image data is erased from the HDD 32. This makes it extremely
difficult to restore the image data.
[0028] In a case where a copy job for less confidential documents
or non-confidential documents is executed, the user selects the
icon of "NO". In this case, the FAT information of the image data
related to this copy job is erased from the HDD 32 by the data
erasing unit 34b. This can shorten an operation time of the HDD 32,
which can in turn suppress deterioration in performance. Also, the
life of the HDD 32 can be extended by reducing the number of
accesses to the HDD 32.
[0029] In this manner, the image forming apparatus 100 erases image
data saved in the HDD 32 by a single method selected by the user
from two methods at different security levels.
[0030] It may be configured in such a manner that the image data
erasing unit 34 causes the liquid crystal display unit 18 to
display a message, "Erasing image data" or "Image data is erased"
at once for a certain time when either the icon of "YES" or "NO"
shown in FIG. 2 is selected.
[0031] There is a case that the user selects neither the icon of
"YES" nor the icon of "NO". This is a case where either the user
ignores the display on the liquid crystal display unit 18, or he
skips a manipulation. When this case is left unresolved, there is a
risk that a trouble occurs in a job execution by the image forming
apparatus 100 thereafter.
[0032] This being the case, a grace time to enable the user to
select the icon of either "YES" or "NO" has been previously set in
the erasing timer set unit 36. In a case where the user selects
neither the icon of "YES" nor the icon of "NO" by the time the
grace time pre-set in the erasing timer set unit 36 has passed, the
image data erasing unit 34 erases the FAT information of the image
data related to this copy job from the HDD 32 after the grace time
has passed. In other words, the data erasing same as that performed
when a copy job for less confidential documents and
non-confidential documents is executed is performed.
[0033] One example of the relation between the grace time and a job
set in the erasing timer set unit 36 is set forth in FIG. 3. The
grace time that can be set in the erasing timer set unit 36
includes, for example, eight kinds: 0 second, 30 seconds, one
minute, two minutes, three minutes, five minutes, 10 minutes, and
30 minutes. One grace time selected from these eight kinds is set
separately for each of a copy job, a PC print job, a scanner job, a
facsimile transmission job, and a facsimile reception job that can
be executed by the image forming apparatus 100. The manager of the
image forming apparatus 100 is able to perform this setting using
the key input unit 16 and the liquid crystal display unit 18.
[0034] It should be noted that the grace time is not limited to the
times specified above. The grace time that can be set is not
limited to eight kinds, either. In a case where the grace time is 0
second, data in the HDD 32 is erased as soon as the job is
completed. In this case, the image data erasing unit 34 does not
cause the liquid crystal display unit 18 to show the display of
FIG. 2. The display of FIG. 2 goes off when the pre-set grace time
has passed.
[0035] For a copy job with which the user often awaits near the
image forming apparatus 100, it is preferable to set the grace time
shorter. On the contrary, for a job when to receive is uncertain,
such as a facsimile reception, it is preferable to set the grace
time longer.
[0036] The processing flow of a copy job using the image forming
apparatus 100 will now be described. FIG. 4 shows the flowchart of
the copy job. Initially, the document is set in the scanner unit 20
(ST1). Reading of the document is started by a manipulation on the
key input unit 16 (ST2). Image data obtained in ST2 is successively
compressed in an appropriate manner and saved in the image data
memory unit 32 (ST3). The data saved in the image data memory unit
32 is read out sequentially and restored to data of its original
size, after which the data is sent to the printing unit 22 and
printed on a sheet of paper therein (ST4).
[0037] At the same time when ST4 is started, a judgment as to
whether printing on a sheet of paper has ended is started (ST5).
When the judgment in ST5 is "YES", the data erasing selection
screen shown in FIG. 2 above is displayed at once on the liquid
crystal display unit 18 (ST6). At the same time when the screen
display in ST6 is performed, the timer operation for the grace time
(that is, count down of the grace time) starts (ST7).
[0038] After ST7 started, whether a selection manipulation has been
made on the data erasing selection screen is judged (ST8). When it
is judged in ST8 that the selection manipulation has been made (in
the case of `YES`), it is further judged as to whether the
selection content is the icon of "YES" or the icon of "NO"
(ST9).
[0039] In a case where the judgment in ST9 is the icon of "YES",
meaningless random data is written over the image data saved in the
HDD 32 for the job (ST10). After the processing in ST10, the FAT
information is successively erased (ST12). Processing on the image
data thus ends. These ST10 and ST12 make it extremely difficult to
reproduce the image data.
[0040] In a case where the judgment of ST9 is the icon of "NO",
erasing processing for the FAT information (ST12) is performed
without performing the data processing in ST10. Processing on the
image data thus ends. In this case, a high performance can be
maintained because the operation time of the HDD 32 is short and
various jobs can be executed at once thereafter.
[0041] In a case where it is judged in ST8 that the selection
manipulation has not been made (in the case of `NO`), whether the
grace time set for the copy job has passed (that is, whether time
is up) is judged (ST11). In ST11, when the specific grace time has
passed (in the case of YES), the erasing processing of the FAT
information (ST12) is performed at once. Processing on the image
data thus ends.
[0042] A case where the image forming apparatus 100 is used as the
printer for the PC 38 will now be described briefly. A print job is
executed for documents or the like created in the PC 38 by
specifying the image forming apparatus 100 as the printer. The
print data generated in the PC 38 is transmitted to the image
forming apparatus 100 and converted into page data therein. The
page data is compressed appropriately, and is then saved in the
image data memory unit 32. The page data saved in the image data
memory unit 32 is read out sequentially to be restored to data of
its original size, after which the data is sent to the printing
unit 22 and printed on a sheet of paper therein.
[0043] When the print processing in the image forming apparatus 100
is completed, the image data erasing unit 34 causes the display of
the PC terminal to display "Print out is completed. Erase Print
data? "YES", "NO"" in the same manner as FIG. 2 using the two-way
communications between the image forming apparatus 100 and the PC.
In this instance, the same display is shown on the liquid crystal
display unit 18 of the image forming apparatus 100. The user is
able to erase the image data saved in the HDD 32 by manipulating
the PC 38 or the liquid crystal display unit 18.
[0044] In a case where the specific grace time has passed while
neither the icon of "YES" nor the icon of "NO" is selected, the
erasing processing of the FAT information is performed at once, and
the message that is being displayed on the PC 38 and the liquid
crystal display unit 18 goes off.
[0045] The data processing method in a case where the image forming
apparatus 100 is used as the transmitter of a facsimile machine is
the same as the case where a copy job is executed. The data
processing method in a case where the image forming apparatus 100
is used as the receiver of a facsimile machine is the same as the
case where a print job is executed. In a case where the image
forming apparatus 100 is used as the scanner, which is a peripheral
device of the PC 38, the configuration can be the same.
[0046] While the embodiment of the present invention has been
described, the invention is not limited to the embodiment above,
and various modifications, alternations, and replacements can be
made by those skilled in the art within the scope of the invention
set forth in the appended claims. It is therefore understood that
such are included in the scope of the invention.
[0047] For example, the image forming apparatus 100 described above
erases data saved in the HDD 32 using the image data erasing unit
34 and the erasing timer set unit 36. The functions of these image
data erasing unit 34 and the erasing timer set unit 36 are exerted
by the CPU 10, the program stored in the ROM 12, the grace time
stored in the RAM 14.
[0048] The security level for image data as an erasure object is
not limited to two scales. It is therefore possible to configure in
such a manner that the user is further able to specify the number
of overwriting times of meaningless random data on the image data
saved in the HDD 32. To be more concrete, in a case where the user
selects the icon of "YES" when the display as shown in FIG. 2 is
displayed on the liquid crystal display unit 18, plural icons
representing the number of overwriting times of random data are
then displayed on the liquid crystal display unit 18. The security
level becomes higher as the number of overwriting times is
increased. The user selects one icon among these plural icons by
taking into account the degree of secrecy of the document he is
handling. Erasing processing of image data that matches with the
selected security level is thus performed.
[0049] The image forming apparatus 100 may be configured in such a
manner that no erasing processing is applied to image data as an
erasure object in a case where the user selects the icon of "NO"
when the display as shown in FIG. 2 is displayed on the liquid
crystal display unit 18. In this case, when a specific job is
executed in the image forming apparatus 100, the CPU 10 detects an
available capacity of the image data memory unit 32. When an
available capacity of the image data memory unit 32 is
insufficient, image data related to jobs in the past is erased
appropriately. This ensures an available capacity needed to execute
a new job in the image data memory unit 32.
[0050] The image forming apparatus 100 may be configured in such a
manner that in a case where the user selects the erasing method of
image data within the grace time set in the erasing timer set unit
36, the selected data erasing method is performed at once when this
grace time has passed. When another job is being executed during
this time, the priority is placed on the performance of the job and
the data erasing processing comes in a pending state. The data
erasing processing is performed at once after the job is
completed.
[0051] The image data memory unit 32 is not limited to an HDD, and
it can be other memory devices capable of reading/writing data, for
example, a DVD-RAM or an MO.
* * * * *