WikiPatents - Community Patent Review
Create Free Account  |  License or Sell Your Patent  |  WikiPatents Marketplace  |  WikiPatents Blog
Username:  Password:  
    
Advanced Search
Image forming apparatus having illegal use prevention    
United States Patent5610688   
Link to this pagehttp://www.wikipatents.com/5610688.html
Inventor(s)Inamoto; Kiyoshi (Sakai, JP); Miyaza; Masao (Osaka, JP); Nakai; Yasuhiro (Kyoto, JP)
AbstractAn image forming apparatus stores an ID number input through an auditor in a memory section when a paper money judging section judges that image data obtained from an image reading section is the image data of paper money. With this structure, the fact that an attempt to perform counterfeiting was made is known by reading out the ID number stored in the memory section. In this case, since it is understood that a counterfeiter knew a specific ID number, the counterfeiter can be detected from a limited number of people. It is thus possible to take some measures to prevent recurrence of counterfeiting by, for example, enhancing the inspection of the image forming apparatus and giving a warning to the counterfeiter.
   














 Title Information Submit all comments and votes
 
Patent Text Patent PDF Print Page Summary File History
Plain text PDF images Print Summary File History
Inventor     Inamoto; Kiyoshi (Sakai, JP); Miyaza; Masao (Osaka, JP); Nakai; Yasuhiro (Kyoto, JP)
Owner/Assignee     Sharp Kabushiki Kaisha (Osaka, JP)
Patent assignment
All assignments
Publication Date     March 11, 1997
Application Number     08/333,348
PAIR File History     Application Data   Transaction History
Image File Wrapper   Patent Term   Fees
Litigation
Filing Date     November 2, 1994
US Classification     399/366 399/15 399/81
Int'l Classification     G03G 021/00
Examiner     Dang; Thu A.
Assistant Examiner    
Attorney/Law Firm    
Address
Parent Case    
Priority Data     Nov 05, 1993[JP]5-276596 Nov 11, 1993[JP]5-282822
USPTO Field of Search     355/201 355/202 355/208 355/203 355/204 355/205 355/206 355/207 355/208 355/209 356/71 382/181 371/22.4 371/22.1 371/24
Patent Tags     image forming illegal prevention
   
Enter a comma (,) or semicolon (;) between multiple tag words/phrases.
Describe this patent:
 Amusing   
 Clever   
 Complex   
 Efficient   
 Historic   
 Important   
 Innovative   
 Interesting   
 Practical   
 Simple   
[no votes]
Patent WIKI

Share information and news about this patent, including information and news about the technology, inventors, company, ligation and licensing.

 References Submit all comments and votes
 
*references marked with an asterisk below are user-added references
 U.S. References
 
Add a new US reference:  
ReferenceRelevancyCommentsReferenceRelevancyComments
5480239
Kim
400/120.09
Jan,1996

[0 after 0 votes]
5430525
Ohta
399/366
Jul,1995

[0 after 0 votes]
5283422
Storch
235/375
Feb,1994

[0 after 0 votes]
5214699
Monroe
713/186
May,1993

[0 after 0 votes]
5138618
Honda
714/25
Aug,1992

[0 after 0 votes]
4974172
Nakai
345/443
Nov,1990

[0 after 0 votes]
4105156
Dethloff
235/441
Aug,1978

[0 after 0 votes]
3997873
Thornton
340/5.6
Dec,1976

[0 after 0 votes]
 Foreign References
 Other References
 Market Review Submit all comments and votes
   
Market Size
Estimate the gross annual revenues of the relevant market sector:
> $10B
$5B - $10B
$2B - $5B
$500M - $2B
$100M - $500M
$10M - $100M
$1M - $10M
$500K - $1M
$100K - $500K
< $100K
[No votes]
$0
 
$0   $2.5B   $5B   $7.5B   $10B
Market Share
Estimate the percentage of the relevant market sector this invention will capture:
75% - 100%
50% - 74.99%
25% - 49.99%
10 - 24.99%
5 - 9.99%
2 - 4.99%
1 - 1.99%
< 1%
[No votes]
0.0%
 
0%   25%   50%   75%   100%
Reasonable Royalty
What percentage of gross sales should the inventor or assignee be paid?
75% - 100%
50% - 74.99%
25% - 49.99%
10 - 24.99%
5 - 9.99%
2 - 4.99%
1 - 1.99%
< 1%
[No votes]
0.0%
 
0%   25%   50%   75%   100%
Public's "Guesstimation" of Royalty Value
Market SizeN/A[No votes]
xMarket ShareN/A[No votes]
xReasonable RoyaltyN/A[No votes]

N/A

License Availablity
If you are NOT the owner or assignee, answer here:
Yes, license is available for purchase

No, license is not currently available



[No votes]
License Availablity
If you ARE the owner or assignee, answer here:
Yes, license is available for purchase

No, license is not currently available



[No votes]
Competitive Advantage
Does this invention have a significant competitive advantage over similar technologies?
Yes

No



[No votes]
Most helpful competitive advantage comment
[No comments]

Commercial Alternatives
Are there viable commercial alternatives for this invention?
Yes

No



[No votes]
Most helpful commercial alternative comment
[No comments]

 Technical Review Submit all comments and votes
 Claims Submit all comments and votes
 


What is claimed is:

1. An image forming apparatus comprising:

a memory;

image reading means for reading an image on a document and converting the image into image data;

image printing means for forming an image on a sheet based on the image data;

identification-information input means for inputting operator identification information for identifying an operator;

image processing means for processing the image data for comparison with a specific image;

specific-image judging means for judging whether the image data is the specific image based on an output from said image processing means;

memory controlling means for storing operation status information including at least the operator identification information of an operator who has tried to carry out an image forming process from the specific image in said memory when the image data obtained from the document is judged to be the specific image by said specific-image judging means; and

operation controlling means for storing pre-registered operator identification information and controlling said image printing means to form an image that is an exact copy of the image data only when operator identification information inputted by an operator coincides with the pre-registered operator identification information and is not included in the operation status information that has been stored in said memory.

2. The image forming apparatus according to claim 1, further comprising operation status information printing means for printing out the operation status information stored in said memory.

3. The image forming apparatus according to claim 1, further comprising:

warning means for giving a warning to an operator,

said operation controlling means controlling said warning means to give a warning to an operator when operator identification information input by the operator through said identification-information input means coincides with the operator identification information stored in said memory.

4. The image forming apparatus according to claim 1, wherein said image printing means comprises:

full-color printing means for forming an image in full color on a sheet by reproducing the color of the document,

said operation controlling means prohibiting said full-color printing means from operating when operator identification information input by an operator through said identification-information input means coincides with the operation identification information stored in said memory.

5. The image forming apparatus according to claim 1, wherein said image printing means comprises:

photograph-mode printing means for forming on a sheet an image with gradations which are faithful reproductions of gradations of the image of the document,

said operation controlling means prohibiting said photograph-mode printing means from operating when operator identification information input by an operator through said identification-information input means coincides with the operator identification information stored in said memory.

6. The image forming apparatus according to claim 1,

wherein said operation controlling means limits an available number of sheets on which an image is to be formed to a predetermined number when operator identification information input by an operator through said identification-information input means coincides with the operator identification information stored in said memory.

7. The image forming apparatus according to claim 1, wherein said image printing means comprises:

double-side printing means for forming images on both sides of a sheet by forming images on each side of the sheet and by automatically transporting, reversing and determining respective positions of the sheet and the document,

said operation controlling means prohibiting said double-side printing means from operating when operator identification information input by an operator through said identification-information input means coincides with the operator identification information stored in said memory.

8. The image forming apparatus according to claim 1, further comprising:

a sheet feed cassette for feeding sheets of a standard size; and

a manual sheet feed section for feeding sheets of desired sizes,

said image printing means including sheet feeding means for selectively feeding a sheet from said sheet feed cassette or said manual sheet feed section,

said operation controlling means prohibiting said sheet feeding means from feeding a sheet from said manual sheet feed section when operator identification information input by an operator through said identification-information input means coincides with the operator identification information stored in said memory.

9. An image forming apparatus comprising:

a memory;

image reading means for reading an image on a document and converting the image into image data;

image printing means for forming an image on a sheet based on the image data;

identification-information input means for inputting operator identification information for identifying an operator;

operation controlling means for storing pre-registered operator identification information and controlling said image printing means to form an image only when operator identification information input by an operator coincides with the pre-registered operator identification information;

image processing means for processing the image data for comparison with a specific image;

specific-image judging means for judging whether the image data is the specific image based on an output from said image processing means;

memory controlling means for storing operation status information including at least the operator identification information of an operator who has tried to carry out an image forming process from the specific image in said memory means when the image data obtained from the document is judged to be the specific image by said specific-image judging means; and

operation status information output means for reading out the operation status information stored in said memory and for displaying or printing the information.

10. The image forming apparatus according to claims 1 or 9, wherein said memory is a non-volatile memory that retains data stored therein even when supply of power is cut off.

11. The image forming apparatus according to claims 1 or 9, further comprising:

a backup power source for supplying power to said memory when supply of power to a main body of the image forming apparatus is cut off.

12. The image forming apparatus according to claims 1 or 9,

wherein said memory is a recording medium which is freely installed in or removed from a main body of the image forming apparatus while retaining data stored thereon.

13. The image forming apparatus according to claim 12,

wherein said recording medium is locked with a lock which is unlocked only by a key possessed by a specific manager.

14. The image forming apparatus according to claims 1 or 9, further comprising:

transmitting means for transmitting data to an external device through a communication network; and

transmission controlling means for controlling said transmitting means to transmit the operation status information including at least the operator identification information to said external device when said specific-image judging means judges that the image data obtained from the document is a specific image.

15. The image forming apparatus according to claims 1 or 9, wherein said identification-information input means comprises:

an identification-information recording medium which is possessed by an operator and on which operator identification information is recorded; and

identification-information reading means, installed in a main body of the image forming apparatus, for reading the operator identification information from said identification-information recording medium.

16. The image forming apparatus according to claims 1 or 9, further comprising information-storage indicating means for indicating that the operation status information has been stored in said memory by said memory controlling means.

17. The image forming apparatus according to claims 1 or 9,

wherein said identification-information input means includes fingerprint reading means for reading a fingerprint of an operator as operator identification information.

18. The image forming apparatus of claim 17, further comprising:

management-information storage means in which a fingerprint of an operator and at least a group to which the operator belongs are registered as operator management information; and

fingerprint comparing means for judging whether an operator is a registered operator based on a fingerprint of the operator read by said fingerprint reading means and the registered operator management information in said management-information storing means and judging a group to which the operator belongs based on the operator management information when the operator is judged a registered operator,

said operation controlling means permitting the operator to start a predetermined operation mode which the group to which the operator belongs is allowed to access.

19. The image forming apparatus according to claim 18, wherein said memory controlling means stores as operation status information at least the fingerprint of the operator in said memory when said specific-image judging means judges that the image data is the specific image,

said output controlling means controlling said image processing means to generate an output image by adding a predetermined pattern to the image data when said specific-image judging means judges that the image data is a specific image.

20. The image forming apparatus according to claim 18, further comprising:

transmitting means for transmitting a warning to an external security system through a communication network; and

transmission controlling means for controlling said transmitting means to transmit the warning to said external security system when said specific-image judging means judges that the image data is the specific image.

21. The image forming apparatus according to claim 18,

wherein said fingerprint reading means includes an optical sensor installed in a switch which is to be depressed with a finger of an operator.

22. The image forming apparatus according to claim 21,

wherein said switch is depressed by an operator to instruct a start of forming an image.

23. The image forming apparatus according to claim 18,

wherein said management-information storage means comprises a non-volatile memory.

24. The image forming apparatus according to claim 18,

wherein, when an operator is judged a registered operator by said fingerprint comparing means and when a group to which the operator belongs is permitted access to only one operation mode, said operation controlling means immediately activates the operation mode.

25. The image forming apparatus according to claim 18, further comprising:

a screen,

said output controlling means displaying a plurality of operation modes which an operator is permitted to operate; and

mode selecting means for selecting an operation mode to be activated from the operation modes displayed on said screen,

said operation controlling means activating the operation mode selected by the operator through said mode selecting means.

26. The image forming apparatus according to claim 18, further comprising:

password input means through which an operator inputs a password; and

password comparing means for judging whether a password input by an operator coincides with a predetermined password,

said operation controlling means permitting the operator to activate a management-information registration mode for registering operator management information of the operator only when said password comparing means judges that the input password coincides with the predetermined password.

27. The image forming apparatus according to claim 18,

wherein a fingerprint of a service engineer is registered as special operator management information which is distinguished from operator management information of ordinary operators in said management-information storage means,

said fingerprint comparing means judging whether an operator is a service engineer based on a fingerprint of the operator read by said fingerprint reading means and the special operator management information, and

said operation controlling means permitting the operator to activate a simulation mode to which only service engineers are allowed to access when said fingerprint comparing means judges that the operator is a service engineer.

28. The image forming apparatus according to claim 18, further comprising:

output means for outputting a sheet having thereon a formed image;

counting means for counting a total number of sheets output by said output means for each group;

upper limit setting means for setting a maximum number of sheets allowed to be output by each group,

said operation controlling means prohibiting an operator belonging to a group which has output the set maximum number of sheets from performing an image forming operation.

29. The image forming apparatus according to claim 28, further comprising:

a screen; and

output controlling means for displaying on said screen group information including a total number of sheets output and a set maximum number of sheets allowed to be output by each group.

30. The image forming apparatus according to claim 28, further comprising output controlling means for printing out group information including a total number of sheets output and a set maximum number of sheets allowed to be output by each group.

31. The image forming apparatus according to claim 28,

wherein said upper limit setting means includes infinity setting means for setting infinity as a maximum number of sheets to be output for a group which is free to output a desired number of sheets.

32. The image forming apparatus according to claim 9,

wherein the operation status information stored in said memory is read out only by an operator who input predetermined operator identification information.

33. The image forming apparatus according to claim 9, further comprising:

initialization permitting means for judging whether to permit an operator to input an instruction to erase the operation status information stored in said memory,

said memory controlling means erasing the operation status information from said memory according to the instruction of the operator only when said initialization permitting means permits the operator to input the instruction.

34. The image forming apparatus according to claim 33, wherein said initialization permitting means comprises:

a separate member provided separate from the image forming apparatus, having a unique feature and possessed by a predetermined manager; and

a main member arranged in a main body of the image forming apparatus and having a unique feature corresponding to the unique feature of said separate member,

said initialization permitting means comparing the unique feature of said separate member with the unique feature of said main member and permitting the operator to input the instruction only when the unique feature of said separate member coincides with the unique feature of said main member.

35. The image forming apparatus according to claim 34,

wherein said separate member is a key, and said main member is a keyhole into which said key is inserted.

36. The image forming apparatus according to claim 33, wherein said initialization permitting means comprises:

password input means through which an operator inputs a password;

password memory means for storing pre-registered passwords; and

password comparing means for comparing a password input by the operator with the pre-registered passwords,

said initialization permitting means permitting the operator to input the instruction only when the input password coincides with one of the pre-registered passwords.

37. The image forming apparatus according to claim 9, further comprising:

initialization permitting means for determining whether an instruction, which is input by an operator to erase the operation status information stored in said memory, is effective or not,

said memory controlling means erasing the operation status information from said memory only when said initialization permitting means determines that the instruction input by the operator is effective.

38. The image forming apparatus according to claim 37, wherein said initialization permitting means comprises:

a separate member provided separate from the image forming apparatus, having a unique feature and possessed by a predetermined manager; and

a main member arranged in a main body of the image forming apparatus and having a unique feature corresponding to the unique feature of said separate member,

said initialization permitting means comparing the unique feature of said separate member with the unique feature of said main member and determining that the instruction input by the operator is effective only when the unique feature of said separate member coincides with the unique feature of said main member.

39. The image forming apparatus according to claim 37, wherein said initialization permitting means comprises:

password input means through which an operator inputs a password;

password memory means for storing pre-registered passwords; and

password comparing means for comparing a password input by the operator with the pre-registered passwords,

said initialization permitting means determining that the instruction input by the operator is effective only when the input password coincides with one of the pre-registered passwords.

40. The image forming apparatus according to claim 9, further comprising:

a clock for outputting date and time,

the operation status information further including date and time which are output from said clock when said specific-image judging means judges that the image data obtained from the document is the specific image.

41. The image forming apparatus according to claim 9, further comprising:

number setting means through which an operator sets a number of sheets to be output,

the operation status information further including the number of sheets to be output, which was set through said number setting means, when said specific-image judging means judges that the image data obtained from the document is the specific image.

42. The image forming apparatus according to claim 9, further comprising:

image-size detecting means for detecting a size of the image from the document,

the operation status information further including a size of the image detected by said image-size detecting means based on a document whose image data was judged the specific image by said specific-image judging means.

43. The image forming apparatus according to claim 9,

wherein the operation status information further includes the image data which was judged the specific image by said specific-image judging means.

44. The image forming apparatus according to claim 9, further comprising:

character-area separating means for separating the image data obtained from the document into a character area and another area,

the operation status information further including image data of the character area separated from the image data which was judged the specific image by said specific-image judging means.

45. The image forming apparatus according to claim 9, further comprising:

data compressing means for compressing an amount of the image data obtained from the document,

the operation status information further including the image data which was judged the specific image by said specific-image judging means and compressed by said data compressing means.

46. The image forming apparatus according to claim 45,

wherein said data compressing means compresses the amount of the image data by converting an image density of the image data into a binary number based on a predetermined threshold value.

47. The image forming apparatus according to claim 45,

wherein said data compressing means compresses the amount of the image data by converting an image density of the image data into a binary number using a dither method.

48. The image forming apparatus according to claim 45,

wherein said data compressing means compresses the amount of the image data by converting an image density of the image data into a binary number using an error diffusing method.

49. An image forming method, which is used in an image forming apparatus capable of forming images in a full-color mode, comprising the steps of:

receiving operator identification information that has been inputted by an operator;

judging whether or not image data representing an image to be formed contains a specific image;

storing operator identification information of an operator who has tried to carry out an image forming process from the image data containing the specific image; and

upon receipt of an instruction for forming an image from an operator, judging whether or not the operator identification information of the operator has been stored as the operator identification information of an operator who has previously tried to carry out an image forming process from image data containing the specific image, prior to the image forming process, and if stored prohibiting the formation of the image in the full-color mode.

50. An image forming method, which is used in an image forming apparatus capable of forming images in a photograph mode wherein gradations of an image of a document is reproducible, comprising the steps of:

receiving operator identification information that has been inputted by an operator;

judging whether or not image data to be used in an image forming process contains a specific image;

storing operator identification information of an operator who has tried to carry out an image forming process from the image data containing the specific image if it is judged that the image data contains the specific image; and

upon receipt of an instruction for forming an image from an operator, judging whether or not the operator identification information of the operator has been stored as the operator identification information of an operator who has previously tried to carry out an image forming process from image data containing the specific image, prior to the image forming process, and if stored prohibiting the formation of an image in the photograph mode.

51. An image forming method, which is used in an image forming apparatus capable of forming images in a double-sided copy mode wherein images on both sides of a document are copied on respective sides of a sheet of paper, comprising the steps of:

receiving operator identification information that has been inputted by an operator;

judging whether or not image data to be used in an image forming process contains a specific image;

storing the operator identification information of an operator who has tried to carry out an image forming process from the image data containing the specific image if it is judged that the image data contains the specific image; and

upon receipt of an instruction for forming an image from an operator, judging whether or not the operator identification information of the operator has been stored as the operator identification information of an operator who has previously tried to carry out an image forming process from image data containing a specific image, prior to the image forming process, and if stored prohibiting formation of an image in the double-sided copy mode.

52. An image forming apparatus comprising:

a memory;

receiving means for receiving image data which has transmitted together with operator identification information by an operator from an external device through a communication network;

image printing means for forming an image on a sheet of paper based on the image data;

image processing means for processing the image data for comparison with a specific image;

specific-image judging means for judging whether the image data is the specific image based on an output of said image processing means;

memory controlling means for storing operation status information including at least the operator identification information of an operator who has tried to carry out an image forming process from the specific image in said memory when the image data obtained from the document is judged to be the specific image by said specific-image judging means; and

operation controlling means for storing pre-registered operator identification information and controlling said image printing means to form an image that is an exact copy of the image data only when the operator identification information inputted by an operator coincides with the pre-registered operator identification information and is not included in the operation status information that has been stored in said memory.

53. An image forming apparatus comprising:

a memory;

identification-information input means for inputting operator identification information for identifying an operator;

image reading means for reading an image on a document and converting the image into image data;

transmitting means for transmitting the image data to an external device through a communication network;

image processing means for processing the image data for comparison with a specific image;

specific-image judging means for judging whether the image data is the specific image based on an output of said image processing means;

memory controlling means for storing operation status information including at least the operator identification information of an operator who has tried to carry out an image forming process from the specific image in said memory when the image data obtained from the document is judged as the specific image by said specific-image judging means;

identification-information judging means for judging whether operator identification information input by an operator through said identification-information input means coincides with the operator identification information stored in said memory; and

operation controlling means for prohibiting said image reading means from reading an image when said identification-information judging means judges that the input operator identification information coincides with the operator identification information stored in said memory.

54. An image forming apparatus comprising:

a memory;

identification-information input means for inputting operator identification information for identifying an operator;

image processing means for processing image data obtained from a document for comparison with a specific image;

specific-image judging means including a first criterion and a second criterion, for judging whether the image data is a specific image in accordance with an output of said image processing means based on the first criterion, and further judging whether the image data is the specific image in accordance with the output based on the second criterion when the image data is judged different from the specific image based on the first criterion, the second criterion being more severe than the first criterion so that the image data is more likely to be judged identical to the specific image based on the second criterion;

operation controlling means for prohibiting forming an image when said specific-image judging means judges that the image data is the specific image based on the first criterion;

memory controlling means for storing operation status information including the operator identification information of an operator who has tried to carry out an image forming process from image data containing the specific image in said memory when said specific-image judging means judges that the image data is the specific image based on the second criterion;

identification-information judging means for judging whether operator identification information input by an operator through said identification-information input means coincides with the operator identification information stored in said memory; and

criteria controlling means for changing the first criterion to be closer to the second criterion when said identification-information judging means judges that the input operator identification information coincides with the operator identification information stored in said memory.

55. An image forming method for use in an image forming apparatus including a memory, comprising the steps of:

a) judging whether image data obtained from a document is a specific image based on a first criterion;

b) prohibiting formation of an image when the image data is judged identical to the specific image in said step a);

c) judging whether the image data is the specific image based on a second criterion when the image data is judged different from the specific image based on the first criterion in said step a), the second criterion being more severe than the first criterion so that image data is more likely to be judged identical to the specific image based on the second criterion; and

d) storing operator identification information of an operator who has tried to carry out an image forming process from image data containing the specific image as specific operator identification information in the memory when the image data is judged the specific image in said step c).

56. The image forming method according to claim 55, further comprising the steps of:

e) judging whether operator identification information input by an operator coincides with the specific operator identification information stored in the memory prior to said step a); and

f) changing the first criterion to be closer to the second criterion prior to said step a) when the operator identification information is judged identical to the specific operator identification information in said step e).

57. An image forming apparatus comprising:

a memory;

receiving means for receiving image data which was transmitted together with operator identification information by an operator from an external device through a communication network;

image printing means for forming an image on a sheet of paper based on the image data;

image processing means for processing the image data for comparison with a specific image;

specific-image judging means for judging whether the image data is the specific image based on an output of said image processing means;

memory controlling means for storing operation status information including at least the operator identification information of an operator who has tried to carry out an image forming process from the specific image in said memory when the image data obtained from the document is judged as the specific image by said specific-image judging means; and

operation status information output means for reading out the operation status information stored in said memory and for displaying or printing the information.

58. An image forming apparatus comprising:

a memory;

identification-information input means for inputting operator identification information for identifying an operator;

image reading means for reading an image on a document and converting the image into image data;

transmitting means for transmitting the image data to an external device through a communication network;

image processing means for processing the image data for comparison with a specific image;

specific-image judging means for judging whether the image data is the specific image based on an output of said image processing means;

memory controlling means for storing operation status information including at least the operator identification information of an operator who has tried to carry out an image forming process from the specific image in said memory when the image data obtained from the document is judged as the specific image by said specific-image judging means; and

operation status information output means for reading out the operation status information stored in said memory and for displaying or printing the information.
 Description Submit all comments and votes
 


FIELD OF THE INVENTION

The present invention relates to an image forming apparatus, such as a color copying machine and a color scanner, for reading images on, for example, a document and outputting the images.

BACKGROUND OF THE INVENTION

In recent years, image forming apparatuses such as full-color copying machines have been developed and widely used. Since these image forming apparatuses produce highly precise reproductions of original images, they may be used for the crime of counterfeiting paper money and securities, for example. In order to prevent such a crime, the following apparatuses have been developed. These apparatuses, for instance, stop copying operations when a copying-prohibited document such as paper money is detected, and prints a particular mark, which has been given to a copying machine, on a copy of the document image so that the copying machine used for producing the copy is identified from the mark on the copy.

For example, apparatuses performing the former function are disclosed in the following documents. Japanese Publication for Unexamined Patent Application No. 83571/1990 and No. 285978/1989 teach apparatuses which store patterns of copying-prohibited documents such as paper money and become inoperable when a document to be copied has one of the patterns stored. Japanese Publication for Unexamined Patent Application No. 205272/1992 and No. 316783/1989 disclose apparatuses which, if a document to be copied is detected as paper money, prints the whole portion corresponding to paper money in deep black or halftone when outputting a copy of the document. The apparatuses which perform the latter function are disclosed in the following documents. Japanese Publication for Unexamined Patent Application No. 294682/1992 and No. 302267/1992 teach apparatuses which print a pattern unique to a copying machine in unnoticeable color or a unique feature of the copying machine, for example, the product number when outputting a copy of the document image.

However, although the above-mentioned conventional structures can prevent a crime, it is impossible to effectively identify the person who committed the socially punishable crime, such as counterfeiting paper money. Hence, the conventional apparatuses can not perfectly prevent counterfeiting of paper money.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image forming apparatus capable of effectively preventing its use for illegal purposes, for example, of counterfeiting paper money.

In order to achieve the above object, an image forming apparatus of the present invention includes:

(1) memory means;

(2) image reading means for reading an image on a document and converting the image into image data;

(3) image printing means for forming an image on a sheet based on the image data;

(4) identification-information input means for inputting operator identification information for identifying an operator;

(5) operation controlling means for storing pre-registered operator identification information and controlling the image printing means to form an image only when operator identification information input by an operator coincides with the pre-registered operator identification information;

(6) image processing means for processing the image data for comparison with a specific image;

(7) specific-image judging means for judging whether the image data is the specific image based on an output from the image processing means; and

(8) memory controlling means for storing operation status information including at least the operator identification information in the memory means when the image data obtained from the document is judged the specific image.

With this structure, since the operation controlling means controls the image printing means to form an image only when operator identification information input by an operator coincides with the pre-registered operator identification information, only an operator who has the pre-registered operator identification information is able to perform image forming operations with the image forming apparatus. Moreover, with this structure, when an image read by the image reading means was judged a specific image of, for example, paper money or securities, i.e, when an attempt to counterfeit such a specific image was made, operation status information including at least the input operator identification information is stored in the memory means. Therefore, if a manager or a service engineer of the image forming apparatus reads out the operation status information from the memory means, the fact that an attempt to perform counterfeiting was made is known. For instance, it is possible to detect the counterfeiter from a range of people who know the operator identification information, based on the operator identification information stored as operation status information in the memory means. As a result, the manager of the image forming apparatus can take some measures to effectively prevent recurrence of counterfeiting by, for example, enhancing the inspection of the image forming apparatus and giving a warning to an operator who is suspected of being the counterfeiter.

In addition, with the structure where the operation controlling means judges whether operator identification information input by an operator through the identification information input means coincides with the operator identification information stored in the memory means, and prohibits the image printing means from forming an image when the input operator identification information coincides with the stored operator identification information, it is possible to surely prevent an operator who has made an attempt to perform counterfeiting from executing counterfeiting action again using the image forming apparatus.

With this structure, if the operation controlling means is arranged to prohibit only a predetermined operation among the image forming operations, i.e., an operation which is likely to be used for a counterfeiting operation, it is possible to reduce recurrence of counterfeiting paper money while minimizing the inconvenience of a user. For instance, the predetermined image forming operation means performs an image forming operation executed in a full-color mode for faithfully reproducing the color of a document, a photograph mode for faithfully reproducing the contrast of a document image by giving priority to the gradations of the document image, or a double-sided copy mode for copying images on both sides of a document onto both sides of a sheet. It is also possible to produce the same effects by limiting an available number of sheets having images thereon to be output to a predetermined number, or prohibiting an image from being formed on a sheet supplied from a manual sheet feed section designed for feeding sheets of a desired size.

With the structure where the memory controlling means stores the date and time when an attempt to perform counterfeiting was made, the number of copies to be output by the counterfeiting operation, the size of and the image data of an image used as an