Anti-counterfeiting device for use in an image-processing apparatus

A character-detecting section detects characters from an image that has been read from a document. In order to allow a character-recognizing section to make a judgement as to whether or not the character is identical to any character of specific documents such as paper money and securities stored in a RAM, a discrimination-level setting section generates discrimination patterns corresponding to the discrimination level, and supplies them to the character-recognizing section. As a result of the judgement based on the discrimination at a low level, if the document is judged as one of the specific documents, a specific-document judging section controls the discrimination-level setting section in order to allow the character-recognizing section to make a re-judgement for identification. Thus, the discrimination-level setting section supplies discrimination patterns at a higher level to the character-recognizing section. This arrangement makes it possible to shorten the processing time that is required for discrimination as to whether or not the document in question is any of the specific documents, as well as making it possible to ensure the reliability of discrimination.

FIELD OF THE INVENTION 
The present invention relates to an anti-counterfeiting device that is 
capable of preventing paper money or other articles from being 
counterfeited and which is installed in image-processing apparatuses that 
release an image read out from a document, such as digital copying 
machines, facsimiles, and scanners. 
BACKGROUND OF THE INVENTION 
In recent years, electrophotographic apparatuses have been developed to 
such a degree that multi-color documents can be copied almost perfectly; 
consequently, it is necessary to provide a method for preventing items, 
such as paper money and securities, from being counterfeited. In this 
connection, for example, a method which is disclosed in Japanese Laid-Open 
Patent Publication No. 205272/1992 (Tokukaihei 4-205272) is listed as one 
of the prior-art anti-counterfeit methods. In this Patent Publication, an 
anti-counterfeiting device is disclosed, which is applied to a digital 
copying machine wherein an image, which has been read from a document by 
using a scanner, is temporarily stored in a memory, and upon copying, the 
image is read from the memory and released. In the anti-counterfeit 
processing, a judgement is made as to what degree a document to be copied 
is similar to relevant image data of any specific document that has been 
preliminarily stored, and in accordance with the degree of similarity, 
processing conditions of masking and UCR for the output image are altered. 
In the prior-art anti-counterfeiting device for the digital copying 
machine, however, the selection is made between the two, that is, a 
counterfeit article and a genuine article, in its discrimination method; 
this might cause an erroneous discrimination between counterfeit and 
genuineness in the case of an image that is at the edge of its 
discrimination level. For example, if a document, which is not a specific 
document, is erroneously discriminated as a specific document, complaints 
might be raised from the user, and the reliability of the device might be 
impaired. 
Further, in the above-mentioned anti-counterfeiting device, if its 
discrimination level is increased, device cost and processing time 
increase. Moreover, the device has a contradictory problem in that if the 
discrimination level is decreased, the possibility of erroneous 
discrimination increases, and if the discrimination level is increased, 
the processing time increases. 
SUMMARY OF THE INVENTION 
The objective of the present invention is to provide an image processing 
apparatus having an anti-counterfeiting device that is capable of 
shortening a discrimination-process time of a specific document as well as 
ensuring the reliability of the device while maintaining the accuracy of 
the discrimination. 
In order to achieve the above-mentioned objective, the anti-counterfeiting 
device of the present invention, which is installed in an image processing 
apparatus having a reading for reading an image from a document and an 
output circuit for releasing an output image derived from the read image, 
is provided with: 
(1) a character detector for detecting a character from the image that has 
been read from the document by the reader; 
(2) a discrimination-pattern storage for storing specific images each of 
which is one portion of an image of paper money; 
(3) a discrimination-pattern supplier for generating discrimination 
patterns corresponding to a discrimination level from the specific images 
stored in the discrimination-pattern storage; 
(4) a judger for making a judgement as to whether or not the document is 
paper money by comparing the detected character with the discrimination 
patterns; 
(5) a discrimination controller which first controls the judger so that the 
judger makes a judgement as to whether or not the document is paper money 
by using discrimination patterns at a predetermined level; if the 
judgement shows that the document is paper money, then controls the 
discrimination-pattern supplier so that the discrimination-pattern 
supplier supplies discrimination patterns at a level higher than the level 
of said discrimination patterns; and controls the judger so that the 
judger makes re-judgement so as to confirm whether or not the document is 
paper money by using the discrimination patterns; and 
(6) an output controller which, if the judger confirms that the document is 
paper money, controls the output circuit so as to stop the output of the 
output image. 
With the above-mentioned arrangement, the character-detector detects a 
character from an image of a document, and the character is compared with 
specific images each of which is one portion of an image of paper money. 
As a result, if the document is Judged as paper money, a re-judgement is 
made so as to confirm whether or not the document is paper money by using 
discrimination patterns at a higher level. If the document is confirmed as 
such, the output controller stops the output of the output image. 
In this arrangement, two judgement-making steps are made: the first 
judgement is made by using discrimination patterns at a comparatively 
lower level, and only in the case where a document appears to be paper 
money, the second judgement is made based on a higher-level examination. 
This reduces the possibility of misjudgement that a document, which is not 
paper money, is Judged as paper money, thereby improving the reliability 
of the anti-counterfeiting device. Further, different from the 
conventional method wherein a document is compared with the entire portion 
of paper money, the above-mentioned control operation restricts the object 
for reference of judgement to one portion on paper money. This makes it 
possible to simplify the judgement and reduce the burden that is imposed 
during judgement, thereby reducing the judging time. 
Moreover, the above-mentioned arrangement may further include a face-value 
discriminator which controls the discrimination-pattern supplier so that 
if the character detected by the character detector means is identical to 
a face value of paper money, it supplies discrimination patterns at a 
higher level in accordance with the increment of the face value. This 
arrangement ensures a more positive judgement by upgrading the accuracy of 
the discrimination in accordance with the increment of the face value; 
therefore, it becomes possible to prevent paper money with high face 
values from being counterfeited. 
Furthermore, the above-mentioned arrangement may also include another 
feature which, if the character detected by the character detector is 
identical to a face value of paper money, supplies the image judger with 
discrimination patterns at a higher level in accordance with the increment 
of the number of output copies that has been entered by the operator 
through an output-copy-number inputter this makes it possible to prevent 
paper money from being counterfeited in a large amount. 
In addition, the anti-counterfeiting device of the present invention, which 
is installed in an image processing apparatus having a reader for reading 
an image from a document and an output circuit for releasing an output 
image derived from the read image, is provided with: 
(1) a self detector for detecting a seal from the image that has been read 
from the document by the reader; 
(2) a seal storage means for preliminarily storing specific seals that are 
put or printed on specific documents; 
(3) a discrimination-pattern supplier for generating discrimination 
patterns in accordance with a discrimination level, the discrimination 
patterns being derived from the specific seals stored in the seal storing 
means; 
(4) a judger for making a judgement as to whether or not the document is 
any of the specific documents by comparing the seal detected by the seal 
detector with the discrimination patterns derived from the specific seals; 
(5) a discrimination controller means which first controls the 
discrimination-pattern supplier so that it generates the outer shapes of 
the specific stamps as discrimination patterns; allows the judger to make 
a judgement as to whether or not the document is any of the specific 
documents; if the judgement shows that the document is one of the specific 
documents, then controls the discrimination-pattern supplier so that the 
discrimination-pattern supplier supplies discrimination patterns at a 
level higher than the level of said discrimination patterns; and controls 
the judger so that the judger makes a re-judgement so as to confirm 
whether or not the document is one of the specific documents by using the 
discrimination patterns; and 
(6) an output controller which, if the judger confirms that the document is 
one of the specific documents, controls the output circuit so as to stop 
the output of the output image. 
In this arrangement, it is possible to make a judgement as to whether or 
not a document is any of the specific documents based on the seals that 
are put or printed on the specific documents. In other words, two 
judgement-making steps are made in the same manner as the aforementioned 
arrangement: the first judgement is made as to whether or not there is a 
specific seal on the document based on the outer shapes of the specific 
seals that are provided as discrimination patterns at a lower level, and 
only in the case where there is a specific seal on the document, the 
second judgement is made as to whether or not the seal on the document is 
any of the specific seals based on a higher-level examination. This 
arrangement prevents the possibility of misjudgement that a document, 
which is not a specific document, is judged as one of the specific 
documents, while maintaining the accuracy of the discrimination. Further, 
different from the conventional method wherein an entire portion of a 
document is used for comparison, only a seal portion of a document is used 
for making a judgement; this makes it possible to reduce the time and 
burden that are required for the judging process. 
Also, the anti-counterfeiting device of the present invention, which is 
installed in an image processing apparatus having a reader for reading an 
image from a document and an output circuit for releasing an output image 
derived from the read image, is provided with: 
(1) a seal storage for preliminarily storing images of specific seals that 
are put or printed on specific documents; 
(2) a seal detector for detecting a seal from the image that has been read 
from the document by the reader and for making a judgement as to the 
degree of importance of the seal based on the style of a character 
contained in the seal; 
(3) a discrimination-pattern supplier for generating discrimination 
patterns in accordance with a discrimination level, the discrimination 
patterns being derived from the images of the specific seals stored in the 
seal storage; 
(4) a judger for making a judgement as to whether or not the document is 
one of the specific documents by comparing the seal with the 
discrimination patterns; 
(5) a discrimination controller which, if a seal is detected by the seal 
detector, first controls the discrimination-pattern supplier so that it 
generates discrimination patterns that are suitable for the degree of 
importance of the seal, and controls the judger so that the judger makes a 
judgement as to whether or not the document is one of the specific 
documents by comparing the seal with the discrimination patterns; and 
(6) an controller means which, if the judger confirms that the document is 
one of the specific documents, controls the output circuit so that the 
output of the output image is stopped. 
With the above-mentioned arrangement, the seal detector makes a judgement 
as to the degree of importance of the seal based on the style of a 
character contained in the seal that has been detected from the image of a 
document. The discrimination-pattern supplier generates discrimination 
patterns in accordance with the degree of importance of the seal, and the 
judger makes a judgement as to whether or not the document is one of the 
specific documents by comparing the seal with the discrimination patterns. 
Normally, specific documents having high degree of importance have seals 
having high degree of importance put or printed on them; therefore, this 
detection of seals makes it possible to effectively recognize specific 
documents. As a result, it becomes possible to effectively prevent 
specific documents from being counterfeited. Since the judgement is made 
based only on the seal portion that is one portion of the document, the 
judging operation is simplified and the burden that is imposed during 
judgement is reduced, thereby reducing the judging time. 
For a fuller understanding of the nature and advantages of the invention, 
reference should be made to the ensuing detailed description taken in 
conjunction with the accompanying drawings.

DESCRIPTION OF THE EMBODIMENTS 
Embodiment 1 
Referring to FIGS. 1 through 13, the following description will discuss one 
embodiment of the present invention. 
As illustrated in FIG. 2, a digital copying machine, which is an 
image-processing apparatus to which the present embodiment is applied, is 
provided with a document platen 27 made of hard transparent glass that is 
installed on the upper portion of a copying machine main body 26. 
Below the document platen 27, are installed a scanner 22 that is 
constituted of a lamp unit 1, mirrors 2, 3 and 4, a lens unit 5, a CCD 
(Charge Coupled Device) sensor 6, and other members. In the scanner 22, a 
document (not shown) placed on the document platen 27 is illuminated by 
the lamp unit 1, and the reflected light is directed to the 
light-receiving face of the CCD sensor 6 through the mirrors 2, 3 and 4 
and the lens unit 5, thereby allowing its image to be read as electric 
signals. 
Below the scanner 22, is installed a laser driver unit 7. The document 
data, which has been read by the CCD sensor 6, is subjected to image 
processings for copying in an image-processing section, not shown, and is 
sent to a laser driver unit 7 as output image data. The laser driver unit 
7 projects laser light from, for example, a semiconductor laser installed 
therein in accordance with the inputted document data. 
The laser light, released from the laser driver unit 7, is reflected by 
mirrors 8 and 9 that are disposed in its light path, and is projected onto 
a photoreceptor drum 10 that rotates in the direction of arrow B, thereby 
forming an electrostatic latent image on the photoreceptor drum 10. On the 
periphery of the photoreceptor drum 10, is disposed a main charger 16 for 
uniformly charging the surface of the photoreceptor drum 10 to a 
predetermined electric potential prior to the exposure made by the laser 
light. Moreover, in the rotating direction of the photoreceptor drum 10 
from the main charger 16, are disposed the following and other devices in 
this order: a developing device 28 for developing the electrostatic latent 
image on the photoreceptor drum 10 by supplying toner thereonto, a 
transferring belt 17 whereon the toner image is temporarily transferred 
from the photoreceptor drum 10, a cleaning device 21 for collecting 
residual toner from the surface of the photoreceptor drum 10, and a 
charge-eliminating lamp 15 for eliminating residual electric potential 
from the photoreceptor drum 10 prior to the next charging operation. 
The developing device 28 includes a black-developer tank 11, a 
yellow-developer tank 12, a magenta-developer tank 13 and a cyan-developer 
tank 14, and each of the developer tanks 11 through 14 contains toner of 
the corresponding color. The transferring belt 17, which is an endless 
belt, is installed so as to freely move in the direction of the arrow, and 
one portion thereof is pressed onto the photoreceptor drum 10, thereby 
allowing the toner image of the photoreceptor drum 10 to be transferred 
thereon. 
Further, on the paper-feeding side of the transferring belt 17, are 
disposed a register roller 19 for supplying sheets of paper to the 
transferring belt 17 with predetermined intervals, a paper-feed cassette 
20 and a manual paper-feed section 23. A paper-feed roller 24 for 
transporting sheets of paper, a transport roller 25 and other members are 
disposed in the vicinity of the paper-feed cassette 20 and the manual 
paper-feed section 23. Below the transferring belt 17, is installed a 
transferring roller 18 which presses a sheet of paper transferred from the 
register roller 19 onto the transferring belt 17 so that the toner image 
on the transferring belt 17 is transferred onto the sheet of paper. 
On the paper-discharging side of the transferring belt 17, are disposed a 
conveyer belt 30 for carrying the sheet of paper that has been subjected 
to the toner-image transferring operation, a fixing device 31 for fixing 
the toner image onto a sheet of paper by heat, and a discharge roller 32 
for discharging the sheet of paper having been subjected to the fixing 
process out of the machine. 
In the above-mentioned arrangement, a color copying operation (3-color 
copying) is carried out in the following sequence. After the main charger 
16 has uniformly charged the surface of the photoreceptor drum 10, the 
scanner 22 conducts the first scanning operation. Thus, respective data of 
the red component (R), green component (G) and blue component (B) of a 
document are read by the CCD sensor 6, and in accordance with the 
respective data, yellow data is first created in the image-processing 
section. A laser light, which is modulated based on the yellow data, is 
released from the laser driver unit 7, and the laser light exposes the 
surface of the photoreceptor drum 10, thereby forming a yellow 
electrostatic latent image at the exposed portion. Successively, yellow 
toner is supplied from the yellow-developer tank 12 to the electrostatic 
latent image formed in the image area, and a toner image having the 
corresponding color is thus formed. 
Next, the yellow toner image is transferred onto the transferring belt 17 
that is being pressed onto the photoreceptor drum 10. At this time, 
although some toner that has not been consumed during the transferring 
process still exists on the surface of the photoreceptor drum 10, the 
cleaning device 21 scrapes the residual toner from the surface. Further, 
the static-eliminating lamp 15 eliminates residual electric charge from 
the surface of the photoreceptor drum 10. 
After completion of the above-mentioned processes, the main charger 16 
uniformly charges the surface of the photoreceptor drum 10 again, and the 
scanner 22 conducts the second scanning operation. Magenta data is created 
in the image-processing section in accordance with the resulting document 
data. A laser light, which is modulated based on the magenta data, is 
projected from the laser driver unit 7 onto the photoreceptor drum 10, 
thereby forming a magenta electrostatic latent image. Successively, 
magenta toner is supplied from the magenta-developer tank 13 to the 
electrostatic latent image, and a toner image having the corresponding 
color is thus formed on the photoreceptor drum 10. Then, the magenta toner 
image is transferred onto the transferring belt 17 so as to be 
superimposed onto the yellow toner image formed thereon. 
After completion of the same processes as described earlier made by the 
cleaning device 21 and the static-eliminating lamp 15, the main charger 16 
uniformly charges the surface of the photoreceptor drum 10 again, and the 
scanner 22 conducts the third scanning operation. A laser light, which is 
modulated based on the cyan data, is projected onto the photoreceptor drum 
10, thereby forming a cyan electrostatic latent image thereon. 
Successively, cyan toner is supplied from the cyan-developer tank 14 to 
the electrostatic latent image, and a toner image having the corresponding 
color is thus formed on the photoreceptor drum 10. Then, the cyan toner 
image is transferred onto the magenta toner image formed on the 
transferring belt 17, thereby completing a final image-superimposing 
process. 
Thereafter, the resulting toner image, which has been subjected to the 
image-superimposing process on the transferring belt 17, is transferred 
onto a sheet of paper by the transferring roller 18, and after the toner 
image is fixed thereon by heat in the fixing device 31, the sheet of paper 
is ejected out of the machine by the discharge roller 32. 
Here, the above-mentioned processes are processes for 3-color copying; and 
in the case of 4-color copying, another process, which uses black toner 
stored in the black-developer tank 11, is added to the above-mentioned 
processes. In contrast, in the case of mono-color copying, only the black 
toner is supplied from the black-developer tank 11 onto an electrostatic 
latent image on the photoreceptor drum 10, and the resulting toner image 
is transferred onto a sheet of paper through the transferring belt 17. 
Moreover, the digital copying machine of the present embodiment is provided 
with an image-processing control section 40 that is shown in FIG. 1. In 
the image-processing control section 40, a plurality of control sections, 
such as a document-reading unit 41 and the laser driver unit 7, are 
controlled by a main CPU (Central Processing Unit) 43. Here, a ROM (Read 
Only Memory) 44 provides areas for storing control programs, and a RAM 
(Random Access Memory) 45 is used as areas for storing the inherent 
parameters of a copying machine and working areas for executing the 
programs. In the present embodiment, the RAM 45 not only has a function 
for temporarily storing images read from documents, but also stores 
figures such as face values in paper money, symbols like YEN, .Yen., $, 
etc., and logos, seals, etc. that are printed on paper money and other 
articles with inherent designs, as will be described later. 
As described earlier, the document-reading unit 41 reads an image from a 
document that is placed on the document platen 27. The document image thus 
read is subjected to image processings in the image-processing section 46, 
wherein, for example, changes in image density and copy magnification are 
made in accordance with desires of the user. The inputted image, thus 
processed in the image-processing section 46, is sent to the laser driver 
unit 7, and is released as laser light that is modulated by the document 
image. FIG. 3 shows an operation-panel control section 47 for controlling 
an operation panel 48 that is installed on the upper face of the 
copying-machine main body 26. The operation panel 48 is provided with: ten 
keys 49 that are used for entering the number of copies, pass-numbers, and 
other numbers; a liquid-crystal display panel 50 for displaying the number 
of copies, messages for the operator, etc.; and other members. 
Moreover, as shown in FIG. 1, the digital copying machine of the present 
embodiment is provided with the following sections that collectively 
function as an anti-counterfeiting device: a character-detecting section 
51 functioning as a character detector; a character-recognizing section 52 
functioning as a judger; a paper-money-pattern storing section 53; a 
discrimination-level setting section 54 functioning as a 
discrimination-pattern supplier a specific-document judging section 55; a 
seal-storing section 56; an output control section 57, etc. 
The character-detecting section 51 selectively detects various characters, 
such as figures, symbols and seals, from the document image that has been 
processed by the image-processing section 46. The character-recognizing 
section 52 makes a judgement as to whether or not a character detected by 
the character-detecting section 51 is identical to any specific image that 
has been preliminarily stored in the RAM 45. Here, the specific images 
include figures such as face values in paper money, symbols like YEN, 
.Yen., $, etc., and logos, seals, etc. that are inherent to paper money 
and other articles. 
The paper-money-pattern storing section 53 stores a plurality of kinds of 
discrimination levels that are used by the specific-document judging 
section 55 so as to judge whether or not the document in question is 
identical to any specific document. When the character-recognizing section 
52 carries out its judgement, the discrimination-level setting section 54 
selectively reads out a discrimination pattern corresponding to the 
discrimination level in question from the discrimination patterns stored 
in the paper-money-pattern storing section 53, and supplies it to the 
character-recognizing section 52. 
When the character-recognizing section 52 has made a judgement that a 
character on a document is identical to any character on paper money or 
other articles by using a discrimination pattern at a lower level, the 
specific-document judging section 55 controls the discrimination-level 
setting section 54 so as to supply to the character-recognizing section 52 
discrimination patterns at a higher level. As will be described later, the 
character-recognizing section 52 makes a re-judgement as to the 
identification by using the discrimination patterns at the higher level. 
Moreover, the specific-document judging section 55 also has a function 
which, in the case when the character detected from the document is a face 
value of paper money, controls the discrimination-level setting section 54 
so as to supply the character-recognizing section 52 with discrimination 
patterns that are suitable for the face value. For example, the 
discrimination-level setting section 54 is controlled by the 
specific-document judging section 55 so that the higher the face value, 
the higher level of discrimination patterns is supplied to the 
character-recognizing section 52. 
Furthermore, the specific-document judging section 55 also has a function 
as an output-copy-number discriminator so that it controls the 
discrimination-level setting section 54 to supply the 
character-recognizing section 52 with discrimination patterns at a higher 
level in accordance with the increment of the number of output copies in 
relation to the number of output copies of a copied image that is 
specified by the user. 
The seal-storing section 56, which stores images of various seals that are 
used in securities, classified documents and other documents, is also 
capable of storing the permissible number of copies for each of the 
various seals, as will be described later. 
Moreover, the output control section 57 controls output operations such as 
the stopping operation for the copying operation when the judgement is 
made that the document is one of the specific documents. 
Referring to FIGS. 4 through 13, the following description will discuss 
respective controlling operations for anti-counterfeit in a digital 
copying machine that is provided with the above-mentioned arrangement. 
First, referring to a flow chart, shown in FIG. 4, as well as FIG. 5, an 
explanation will be given on a controlling operation wherein: if a figure 
in characters detected from a document is identical to any figure 
corresponding to a face value in paper money, a judgement is made as to 
whether or not the document is paper money after increasing the level of 
discrimination; and if the judgement is made as such, a warning is given 
and the copying operation is stopped. 
Now, suppose that a document 60, which contains a figure portion 61 of the 
printed figure "1000" as shown in FIG. 5, is placed on the apparatus. 
First, in order to make a judgement as to whether or not the figure 
printed on the document 60 is identical to any face value in paper money, 
such as 1000, 5000, or 10000 in the case of yen paper money, the first 
discrimination level, which is a lower level in discrimination patterns, 
is set by the specific-document judging section 55 (S1). Thus, 
discrimination patterns corresponding to the first discrimination level 
are supplied to the character-recognizing section 52 by the 
discrimination-level setting section 54. 
Here, as will be described later, the first discrimination level 
corresponds to discrimination patterns in a lower level that are commonly 
used in a judgement as to whether or not a symbol used in a document is 
identical to any symbol of unit, such as .Yen. or $, used in paper money 
as well as in a judgement as to whether or not a seal used in a document 
is identical to any seal in paper money. The first discrimination level is 
used for making a comparison, for example, in the level of binary-coded 
images. 
Next, when the number of output copies is entered through ten keys 49 
installed on the operation panel 48 shown in FIG. 3, if necessary, and a 
print key, not shown, is depressed (S2), the scanner 22 scans the document 
60, and the document image is stored in the RAM 45 (S3). 
Successively, the character-detecting section 51 detects a character from 
the document image stored in the RAM 45, and further examines the 
character as to whether or not it is a figure (S4). As for this detection 
as to whether or not the document image contains any figure, it is 
possible to apply a method of extracting features of characters as well as 
a method of using character recognition. 
More specifically, the character-detecting section 51 carries out the 
following processings in order to make the character-recognition more 
efficiently, prior to recognizing characters. For example, shadow portions 
are erased by using the binary-coding processing of an image; void 
characters are detected based on the background and character balance of 
the binary-coded image data; and in the case of void characters, the 
black-white reversing process is carried out. Thus, these processings make 
it possible to convert document images into images that are processed more 
easily. In addition, characters are simplified by the line-narrowing 
process, extraction of connecting components and other processes. 
Thereafter, the inputted image is separated into connected graphic units by 
using features, such as "having a small character", "having an isolated 
character" and "having aligned characters", and a judgement is made as to 
whether or not the graphic form is identical to any character size. Then, 
the separated graphic units are compared with figure patterns, thereby 
detecting characters. 
By using the above-mentioned methods, the figure portion 61 in the document 
60 is divided into graphic units 61a through 61d as indicated by portions 
enclosed by broken lines in FIG. 5. Further, by comparing these with 
figure patterns, the graphic unit 61a is detected as "1" as a character, 
and the graphic units 61b through 61d are detected as "0" as a character. 
If a figure is detected at S4 in the manner as described above, a judgement 
is made as to whether or not the figure is identical to any face value of 
paper money, by comparing the image of the figure portion 61 with the 
discrimination patterns (S5). If the judgement shows that the figure is 
identical to a face value of paper money at S5, the specific-document 
judging section 55 selects the second discrimination level, which is a 
level higher than the first discrimination level in discrimination 
patterns, and controls the discrimination-level setting section 54 so that 
the discrimination-level setting section 54 reads the discrimination 
pattern corresponding to the second discrimination level from the 
paper-money- pattern storing section 53 and supplies them to the 
character-recognizing section 52 (S6). Here, the discrimination patterns 
corresponding to the second discrimination level are, for example, 
discrimination patterns that are used for comparing a document with an 
image of paper money by using image data represented by multi-gradation. 
Then, the character-recognizing section 52 again makes a judgement as to 
whether or not the image of the figure in the inputted document is 
identical to the image of the figure in the face value of paper money by 
using the discrimination patterns corresponding to the second 
discrimination level (S7). If the judgement shows that the image of the 
figure in the inputted document is identical to the image of the figure in 
the face value of paper money, a warning display is given on the liquid 
crystal display panel 50 in the operation panel 48 through a control 
operation of an operation panel control section 47, and the copying 
operation of the copying machine main body 26 is stopped (S8) by the 
controlling operation of the output control section 57. 
Moreover, if the judgement is "NO" at S4, S5 and S7, it is determined that 
the character in question is neither a figure, nor a face value of paper 
money, and that the document in question is not paper money; therefore, 
the ordinary copying operation is carried out (S9). 
As described above, a figure is detected as a character from an image of a 
document, and if the figure is identical to any face value of paper money, 
a re-judgement is made by upgrading the level of discrimination and using 
discrimination patterns that allow the image of the figure in the document 
to be examined in more detail. This arrangement makes it possible to 
improve the reliability of the judgement as to, whether or not the 
document in question is paper money. In other words, two judgement-making 
steps are made: the first judgement is made by using discrimination 
patterns at a lower level, and only in the case where a document appears 
to be paper money, the second judgement is made based on a higher-level 
examination. Therefore, this reduces the possibility of misjudgement that 
a document, which is not paper money, is judged as paper money, thereby 
improving the reliability of the anti-counterfeiting device. 
Different from the conventional method wherein a document is compared with 
the entire portion of paper money, the above-mentioned control operation 
restricts the object for reference of judgement to character portions on 
paper money. This makes it possible to simplify the judgement and reduce 
the burden that is imposed during judgement, thereby reducing the judging 
time. 
Next, referring to a flow chart, shown in FIG. 6, as well as FIG. 7, an 
explanation will be given on a controlling operation wherein: a figure is 
detected as a character from an image of a document; if the figure is 
identical to any face value in paper money, a judgement is made as to 
whether or not the document is paper money after increasing the level of 
discrimination in accordance with the increment of the face value; and if 
the judgement is made as such, a warning is given and the copying 
operation is stopped. In this case also, it is supposed that a document 
60, which contains a figure portion 61 of the printed figure "1000" as 
shown in FIG. 7, is placed on the apparatus. Here, this controlling 
operation is obtained by replacing S6 in the flow chart of FIG. 4 with S10 
which will be discussed later. 
If a figure "1000" is detected from the figure portion 61 of the document 
60 at S4 shown in FIG. 6 in a manner as described above, a judgement is 
made as to whether or not the figure is identical to any face value of 
paper money (S5). 
If the judgement shows that the figure is identical to a face value of 
paper money at S5, the specific-document judging section 55 sets a 
discrimination level that is suitable for the face value in question as 
the third discrimination level, and controls the discrimination-level 
setting section 54 so that it supplies the discrimination patterns 
corresponding to the third discrimination level to the 
character-recognizing section 52 (S10). For example, if the figure is 
1000, the discrimination level for making a comparison based on 
binary-coded images is set as the third discrimination level; if the 
figure is 5000, the discrimination level for making a comparison based on 
black-and-white, multi-gradation images is set as such; and if the figure 
is 10000, the discrimination level for making a comparison based on 
full-color images is set as such. 
Additionally, another setting method for the discrimination level may be 
adopted, wherein the document image is divided into blocks and the number 
of the divisions is changed in order to make a more detailed 
discrimination in accordance with the increment of the face value. 
Then, a judgement is made again as to whether or not the figure in the 
document is identical to the figure in the face value of paper money by 
using the third discrimination level that is set in accordance with the 
face value (S7). In the same manner as shown in FIG. 4, if the judgement 
shows that it is identical to the figure in the face value of paper money, 
a warning display is given on the liquid crystal display panel 50 in the 
operation panel 48 through the controlling operation of the operation 
panel control section 47, and the copying operation of the copying machine 
main body 26 is stopped (S8) through the controlling operation of the 
output control section 57. Moreover, if the judgement is "NO" at S4, S5 
and S7, it is determined that the character in question is neither a 
figure, nor a face value of paper money, and that the document in question 
is not paper money; therefore, the ordinary copying operation is carried 
out (S9). 
As described above, a figure is detected as a character from an image of a 
document, and if the figure is identical to any face value of paper money, 
a re-judgement is made by upgrading the level of discrimination in 
accordance with the increment of the face value and using discrimination 
patterns that allow the image of the figure in the document to be examined 
in more detail. In addition to the aforementioned effects, this 
arrangement makes it possible to prevent paper money with high face values 
from being counterfeited and to reduce the possibility of losses due to 
paper-money counterfeit. 
Next, referring to a flow chart, shown in FIG. 8, as well as FIG. 9, an 
explanation will be given on a controlling operation wherein: a figure is 
detected as a character in a document; if the figure is identical to any 
face value in paper money, a judgement is made as to whether or not the 
document is paper money after upgrading the level of discrimination in 
accordance with the face value and the increment of the number of output 
copies that is specified by the user as output copy number; and if the 
judgement is made as such, a warning is given and the copying operation is 
stopped. Here, in this controlling operation, only S6 and the steps 
thereafter are changed from the sequence of the flow chart shown in FIG. 
4. In this case also, it is supposed that a document 60, Which contains a 
figure portion 61 as shown in FIG. 9, is placed on the apparatus. 
As was described earlier by reference to S4 in FIG. 8, if a figure "1000" 
is detected from the figure portion 61 of the document 60 as shown in FIG. 
9, a judgement is made as to whether or not the figure is identical to any 
face value of paper money (S5). 
If the judgement shows that the figure is identical to a face value of 
paper money at S5, a confirmation is made as to the number of output 
copies that has been specified (S11). Then, the specific-document judging 
section 55 selects a discrimination level that is suitable for the face 
value that is found to be identical to the figure on the document at S5 
and the number of output copies that has been confirmed at S11, and the 
resulting level is set as the fourth discrimination level. This selection 
is made from discrimination levels that are provided in a step-wise manner 
in relation to face values and the numbers of output copies. Further, the 
specific-document judging section 55 controls the discrimination-level 
setting section 54 so that it supplies the discrimination patterns 
corresponding to the fourth discrimination level to the 
character-recognizing section 52 (S12). 
For example, if the figure is 1000, the discrimination level for making a 
comparison based on binary-coded images is set as the fourth 
discrimination level; if the figure is 5000, the discrimination level for 
making a comparison based on black-and-white, multi-gradation images is 
set as such; and if the figure is 10000, the discrimination level for 
making a comparison based on full-color images is set as such. The 
discrimination patterns that correspond to the respective discrimination 
levels are supplied to the character-recognizing section 52. 
Further, in addition to this setting, the following setting is adopted: 
upon making a discrimination, the document image is divided into blocks 
and the number of the divisions is changed in accordance with the number 
of output copies. In other words, as shown in FIG. 9, if the number of 
output copies is set to one sheet, the document 60 is divided into a 
plurality of blocks by using a block 60a as one unit; if the number of 
output copies is set to 2 to 10 sheets, a block 60b is used as one unit; 
and if the number of output copies is set to more than 11 sheets, a block 
60c is used as one unit. 
As is clearly shown in FIG. 9, the greater the number of output copies 
specified, the larger the block unit to be used to divide the document 60, 
thereby providing a more detailed discrimination. 
Then, a judgement is made again as to whether or not the figure in the 
document is identical to the figure in the face value of paper money by 
using the fourth discrimination level that is set in accordance with the 
face value and the number of output copies (S7). In the same manner as 
shown in FIG. 4, if the judgement shows that it is identical to the figure 
in the face value of paper money, a warning display is given on the liquid 
crystal display panel 50 in the operation panel 48 through the controlling 
operation of the operation panel control section 47, and the copying 
operation of the copying machine main body 26 is stopped (S8) through the 
controlling operation of the output control section 57. Moreover, if the 
judgement is "NO" at S4, S5 and S7, it is determined that the character in 
question is neither a figure, nor a face value of paper money, and that 
the document in question is not paper money; therefore, the ordinary 
copying operation is carried out (S9). 
As described above, a figure is detected as a character from an image of a 
document, and if the figure is identical to any face value of paper money, 
a re-judgement is made by upgrading the level of discrimination in 
accordance with the face value and the number of outputs specified and 
using discrimination patterns that allow the image of the figure in the 
document to be examined in more detail. In the same manner as described 
earlier, this arrangement makes it possible to reduce the possibility of 
losses due to paper-money counterfeit. 
Furthermore, in the anti-counterfeiting device of the present embodiment 
for use in a digital copying machine, it is possible to detect not only 
figures, as described above, but also symbols, upon detecting any 
characters. 
Next, referring to a flow chart, shown in FIG. 10, as well as FIG. 11, an 
explanation will be given on a controlling operation wherein: a figure is 
detected from a document as a character; if the figure is identical to any 
unit symbol in paper money, a judgement is made as to whether or not the 
document is paper money after upgrading the level of discrimination; and 
if the judgement is made as such, a warning is given and the copying 
operation is stopped. In this case, it is supposed that a document 62, 
which contains an area 63 having a printed face value "1000 YEN" shown in 
FIG. 11, is placed on the apparatus. 
As shown in FIG. 10, in order to make a judgement as to whether or not a 
figure used in a document is identical to any unit symbol in paper money, 
such as YEN, .Yen., or S, the first discrimination level, which is a lower 
level in discrimination patterns, is set (S1). 
When the print key is depressed by the user (S2), the scanner 22 scans a 
document, and the image of the document 62 thus read is stored in the RAM 
45 (S3). 
Successively, the character-detecting section 51 carries out a symbol 
detection as to whether or not the document image contains a symbol (S14). 
If a symbol is detected, a judgement is made as to whether or not the 
symbol is identical to any unit symbol in paper money (S15). Here, as for 
this detection as to whether or not the document image contains a symbol 
in its characters, it is possible to apply a method of extracting features 
of characters as well as a method of using character recognition, in the 
same manner as the aforementioned step S5. More specifically, the area 63, 
which has been detected by the character-detecting section 51, is further 
divided into, for example, graphic units 63a, 63b and 63c. Here, although 
not shown in the drawing, the portion having the printed figure "1000" is 
also divided into respective graphic units in the same manner as described 
above. The judgement is made as to whether or not the symbol detected from 
the document is identical to any unit symbol in paper money based on these 
graphic units. 
If the judgement shows that the symbol is identical to a unit symbol of 
paper money at S15, the specific-document judging section 55 sets the 
second discrimination level, which is a level higher than the first 
discrimination level in discrimination patterns, in order to make a more 
detailed check on the symbol. In other words, the specific-document 
judging section 55 controls the discrimination-level setting section 54 so 
that it supplies the discrimination patterns corresponding to the second 
discrimination level to the character-recognizing section 52 (S16). Here, 
the discrimination patterns corresponding to the second discrimination 
level are image patterns of unit symbols in paper money that are expressed 
in more detail compared to the discrimination patterns corresponding to 
the first discrimination level. Then, a judgement is made again as to 
whether or not the image of the symbol in the inputted document is 
identical to the unit symbol of paper money by using the second 
discrimination level (S17). If the judgement shows that it is identical to 
the unit symbol of paper money, warning display is given on the liquid 
crystal display panel 50 in the operation panel 48 through the controlling 
operation of the operation panel control section 47, and the copying 
operation of the .copying machine main body 26 is stopped (S8) through the 
controlling operation of the output control section 57. 
Moreover, if the judgement is "NO" at S14, S15 and S17, it is determined 
that the character in question is neither a figure, nor a face value of 
paper money, and that the document in question is not paper money; 
therefore, the ordinary copying operation is carried out (S9). 
As described above, a symbol is detected as a character from an image of a 
document, and if the symbol is identical to any unit symbol printed on 
paper money, a re-judgement is made by upgrading the level of 
discrimination and using discrimination patterns that allow the image of 
the symbol in the document to be examined in more detail. This arrangement 
makes it possible to improve the reliability of the judgement as to 
whether or not the document in question is paper money. In other words, 
two judgement-making steps are made: the first judgement is made by using 
discrimination patterns at a lower level, and only in the case where a 
document appears to be paper money, the second judgement is made based on 
a higher-level examination. Therefore, this reduces the possibility of 
misjudgement that a document, which is not paper money, is judged as paper 
money, thereby improving the reliability of the anti-counterfeiting 
device. Moreover, different from the conventional method wherein a 
document is compared with the entire portion of paper money, the 
above-mentioned control operation restricts the object for reference of 
judgement to unit symbol portions on paper money. This makes it possible 
to simplify the judgement and reduce the burden that is imposed during 
judgement, thereby reducing the judging time. 
Moreover, in the present anti-counterfeiting device, it is possible to 
detect seals and other articles printed on paper money as one form of 
characters by using the character-detecting section 51. In other words, a 
seal on a document is detected as a character, and if the seal is 
identical to any seal of paper money in its shape and size, a judgement is 
made as to whether or not it is paper money after upgrading the level of 
discrimination. If the judgement shows that it is paper money, a warning 
is given and the copying operation is stopped. Referring to a flow chart, 
shown in FIG. 12, as well as FIGS. 13(a) and 13(b), the following 
description will discuss this controlling operation. 
Here, as for seals printed on paper money, for example, a stamp 69 printed 
on the right hand in the center of the 10-dollar bill 68 shown in FIG. 
13(b), or other seals and logos that are printed on paper money in various 
countries with their inherent designs, may be listed. Here, anything may 
be used as long as it shows an identification of paper money: this 
arrangement is not intended to be limited to the above-mentioned seal or 
logo. 
In this case, it is supposed that a document 66 whereon a seal 67 is put or 
printed as shown in FIG. 13(a) is placed on the apparatus. 
First, in order to make a judgement as to whether or not a seal used in a 
document is identical to any seal printed on paper money, the 
specific-document judging section 55 sets the first discrimination level, 
which is a lower level in discrimination patterns (S1). Next, when the 
print key is depressed by the user (S2), the document 66 is scanned, and 
the image of the document 66 is stored in the RAM 45 (S3). 
Successively, the character-detecting section 51 carries out a detection as 
to whether or not the image of the document stored in the RAM 45 contains 
a seal (S21). Here, as for this detection as to whether or not the image 
of the document contains a seal, it is possible to apply a method of 
extracting features of characters as well as a method of using character 
recognition, in the same manner as the aforementioned S5. 
If a seal is detected from the image of the document at S21, a judgement is 
made as to whether or not the seal is identical to any seal printed on 
paper money (S22). More specifically, the judgement is made as to whether 
or not the seal is identical to any seal of paper money in its shape and 
size. 
If the judgement shows that the seal in the document image is identical to 
a seal of paper money in its shape and size, the specific-document judging 
section 55 selects the second discrimination level, which is a level 
higher than the first discrimination level in discrimination patterns, and 
controls the discrimination-level setting section 54 so that it supplies 
the discrimination patterns corresponding to the second discrimination 
level to the character-recognizing section 52 (S6). 
Then, the character-recognizing section 52 makes a more detailed judgement 
as to whether or not the seal in the document image is identical to the 
seal of paper money by using the second discrimination level (S7). 
If the judgement shows that it is identical to the seal of paper money, a 
warning display is given on the liquid crystal display panel 50 in the 
operation panel 48, and the copying operation of the copying machine main 
body 26 is stopped (S8) through the controlling operation of the output 
control section 57. 
Moreover, if the judgement is "NO" at S21, S22 and S7, it is determined 
that the seal in question is neither a seal, nor a seal of paper money, 
and that the document in question is not paper money; therefore, the 
ordinary copying operation is carried out (S9). 
As described above, first, a judgement is made as to whether or not a seal, 
which has been detected from a document as a character by the 
character-detecting section 51, is identical to any seal printed on paper 
money in its shape and size, and if the seal is identified as such, a more 
detailed re-judgement is made on the seal portion in question by upgrading 
the level of discrimination. This arrangement makes it possible to improve 
the reliability of the anti-counterfeiting device as well as shortening 
the judging time in the same manner as described earlier. 
As described above, in the anti-counterfeiting device of the present 
invention for use in the digital copying machine, the character-detecting 
section 51 first detects a character, such as a figure, a symbol or a 
seal, from an image that has been read from a document and that has been 
stored in the RAM 45. Upon detection of any character, the 
discrimination-pattern setting section 54 reads discrimination patterns at 
a low level from the paper-money-pattern storing section 53, and supplies 
them to the character-recognizing section 52. According to these 
discrimination patterns, the character- recognizing section 52 makes a 
judgement as to whether or not the character in question of the document 
image detected by the character-detecting section 51 is identical to any 
one of the characters, that is, face values of paper money, unit symbols, 
such as YEN, .Yen., and S, and seals of paper money. 
If it is judged that the character is identified in the discrimination 
patterns in the low level, the specific-document judging section 55 
controls the discrimination-level setting section 54 so that it supplies 
the character-recognizing section 52 with discrimination patterns at a 
higher level. Then, the character-recognizing section 52 makes a more 
detailed re-judgement as to whether or not the character in question is 
identical to any character, such as a face value, a unit symbol or a seal, 
by using the discrimination-patterns at the higher level. 
Conventionally, the entire portion of paper money has been used as an 
object for identification in order to make a judgement as to whether or 
not the document in question is paper money; this results in prolonged 
processing time for judgement. In contrast, the present embodiment 
restricts the object for identification to character portions on paper 
money. This makes it possible to simplify the judgement and reduce the 
burden in the discrimination, thereby reducing the judging time while 
maintaining accuracy in judgement. Further, even in the case of a doubtful 
discrimination, the discrimination is again made after upgrading the level 
of discrimination, thereby ensuring the reliability of the device. 
Embodiment 2 
Referring to FIGS. 1, 14 and 15, the following description will discuss 
another embodiment of the present invention. Here, for convenience of 
explanation, those members that have the same functions and that are 
described in embodiment 1 with reference to its drawings are indicated by 
the same reference numerals and the description thereof is omitted. 
In the anti-counterfeiting device of the present embodiment for use in the 
digital copying machine, a seal-storing section 56 (seal storage), shown 
in FIG. 1, stores seals that are put or printed on specific documents the 
copies of which are to be prohibited, such as paper money, securities and 
classified documents. 
In the anti-counterfeiting device, the specific documents are detected by 
detecting seals from documents as characters. When any possible specific 
document is detected, a further judgement is made as to whether or not the 
document in question is a specific document by upgrading the level of 
discrimination and comparing the seal on the document with the seal on the 
specific document more closely. If the judgement is made as such, a 
warning is given and the copying operation is stopped. 
Here, as shown in FIG. 15, it is supposed that a document 70 whereon a seal 
71 is put or printed is placed on the apparatus. 
As shown in FIG. 14, in order to make a judgement as to whether or not a 
seal used in a document is identical to any seal put or printed on one of 
specific documents, the first discrimination level, which is a lower level 
in discrimination patterns, is set (S1). 
When the print key is depressed (S2), the document 70 is scanned, and the 
image of the document is stored in the RAM 45 (S3). 
Successively, a seal detection is carried out to find whether or not the 
document image contains a seal that is identical to any seal of specific 
documents stored in the seal-storing section 56 (S21). As for this 
detection as to whether or not the document image contains any seal, it is 
possible to apply a method of extracting features of characters as well as 
a method of using character recognition, in the same manner as S5 of 
Embodiment 1. 
When the seal 71 is detected at S21, a judgement is made as to whether or 
not the seal 71 is identical to any seal used in one of the specific 
documents (S31). More specifically, the judgement is made as to whether or 
not the seal 71 is identical to any seal stored in the seal-storing 
section 56 in its shape and size. 
If the judgement shows that the seal 71 on the document is identical to a 
seal of one of the specific documents, the second discrimination level, 
which is a level higher than the first discrimination level in 
discrimination patterns, is set in order to make a more detailed check on 
the seal (S6). In other words, the specific-document judging section 55 
controls the discrimination-level setting section 54 so that it receives 
the discrimination patterns corresponding to the second discrimination 
level from the seal-storing section 56 and supplies them to the 
character-recognizing section 52. 
Then, the character-recognizing section 52 makes a re-judgement as to 
whether or not the seal 71 on the document 70 is identical to the seal of 
one of the specific documents by using the second discrimination level 
(S32). As a result, if the seal is identified as such, a warning display 
is given on the liquid crystal display panel 50 in the operation panel 48, 
and the copying operation of the copying machine main body 26 is stopped 
(S8) through the controlling operation of the output control section 57. 
Moreover, if the judgement is "NO" at S21, S31 and S32, it is determined 
that the seal in question is neither a seal, nor a seal of a specific 
document, and that the document in question is not a specific document; 
therefore, the ordinary copying operation is carried out (S9). 
As described above, in the anti-counterfeiting device of the present 
embodiment for use in the digital copying machine, the character-detecting 
section 51 detects the seal 71 from the document image that have been read 
from the document 70. Upon detection of the seal 71, the 
character-recognizing section 52 functioning as the seal judger, which is 
first supplied with discrimination patterns in a lower level from the 
discrimination-level setting section 54, makes a judgement as to whether 
or not the seal 71 is identical to any seal that is used in, for example, 
paper money, securities and classified documents and that has been stored 
in the seal-storing section 56. When the judgement shows that the seal is 
identified in the discrimination patterns in the lower level, the 
specific-document judging section 55, controls the discrimination-level 
setting section 54 so that it supplies the character-recognizing section 
52 with discrimination patterns at a higher level. Then, the 
character-recognizing section 52 make a judgement again as to the 
identification by using the discrimination patterns at the higher level. 
Conventionally, in order to make a judgement as to whether or not a 
document in question is any one of various specific images such as paper 
money, securities and classified documents, the entire portion of various 
specific images has been used as an object for identification; this 
results in prolonged processing time for judgement. In contrast, the 
present embodiment restricts the object for identification to seal 
portions on the various specific images, that is, makes the judgement by 
using only seals. This makes it possible to simplify the judgement and 
reduce the burden in the discrimination, thereby reducing the judging 
time. Further, even in the case of a doubtful discrimination, the 
reliability of the discrimination is maintained by upgrading the level of 
discrimination. In other words, it is possible to shorten the judging time 
while maintaining the reliability of the discrimination. 
Moreover, this arrangement allows the device to deal with not only paper 
money but also various articles, such as securities and classified 
documents, from which the image-outputting operation should be prohibited; 
therefore, the applicability of the device is improved. 
Embodiment 3 
Referring to FIGS. 1, 16 and 17, the following description will discuss 
still another embodiment of the present invention. Here, for convenience 
of explanation, those members that have the same functions and that are 
described in the aforementioned Embodiment 1 and Embodiment 2 with 
reference to their drawings are indicated by the same reference numerals 
and the description thereof is omitted. 
Meanwhile, it is a custom in Japan that registered seals, which are put on 
important documents such as securities, are made by using characters 
having a special style that are hard to recognize. In the 
anti-counterfeiting device of the present embodiment for use in the 
digital copying machine, a seal is detected as a character in a document; 
if the style of the seal is hard to recognize like that of a registered 
seal, a judgement is made as to whether or not the document in question is 
identical to any bond of securities that are output-prohibited documents 
after upgrading the level of discrimination; and if the judgement is made 
as such, a warning is given and the copying operation is stopped. 
As shown in FIG. 16, in order to make a judgement as to whether or not a 
seal used in a document is identical to any seal used in output-prohibited 
documents that are possible targets for forgery or counterfeiting by using 
the style of the seal, the first discrimination level, which is a lower 
level in discrimination patterns, is set (S1). When the print key is 
depressed (S2), the document is scanned, and the image of the document is 
stored in the RAM 45 (S3). 
Successively, a seal detection is carried out to find whether or not the 
document image contains a seal, in the same manner as S5 of Embodiment 1 
(S21). If a seal is detected, a judgement is made as to whether or not the 
seal is a registered seal based on whether or not the seal is recognized 
as a character as well as based on its style (S41). 
If the judgement shows that the seal is a registered seal, the second 
discrimination level, which is a level higher than the first 
discrimination level in discrimination patterns, is set in order to make a 
more detailed check on the seal (S6). Then, a judgement is made again as 
to whether or not the seal in the document image is identical to any seal 
on a security bond by using the second discrimination level (S42). If the 
judgement shows that it is identical to a seal of a security bond, a 
warning display is given on the liquid crystal display panel 50 in the 
operation panel 48, and the copying operation of the copying machine main 
body 26 is stopped (S8). 
Moreover, if the judgement is "NO" at S21, S41 and S42, it is determined 
that the seal in question is neither a seal, nor a registered seal, and 
that the document in question is not a security bond; therefore, the 
ordinary copying operation is carried out (S9). FIG. 17 illustrates the 
above-mentioned controlling operation. 
As described above, in the anti-counterfeiting device of the present 
embodiment for use in the digital copying machine, if the 
character-recognizing section 52 functioning as the seal detector, makes a 
judgement that a seal, which has been detected by the character-detecting 
section 51 shown in FIG. 1 as the seal detector, is not identical to any 
seal stored in the seal-storing section 56 functioning as the seal 
storage, and if a judgement is also made that the seal is a registered 
seal based on its style, the level of discrimination is increased. 
Thus, the first judgement is made based on only the seal and its style; 
therefore, in the case of images that are objects whose image-outputting 
operation should be prohibited, it becomes possible to shorten 
discrimination-processing time, as well as making it possible to ensure 
the reliability of discrimination. 
Embodiment 4 
Referring to FIGS. 1, 18 through 27, the following description will discuss 
still another embodiment of the present invention. Here, for convenience 
of explanation, those members that have the same functions and that are 
described in the aforementioned Embodiments 1 through with reference to 
their drawings are indicated by the same reference numerals and the 
description thereof is omitted. 
The anti-counterfeiting device of the present embodiment for use in the 
digital copying machine provides controlling operations wherein: a seal is 
detected as a character in a document; in accordance with the results of 
the seal detection, a judgement is made as to whether the document in 
question is included in output-prohibited documents; and the copying 
operation is restricted. 
As shown in FIG. 18, in order to make a judgement as to whether or not a 
seal used in a document is identical to any seal used in output-prohibited 
documents that are possible targets for forgery or counterfeiting by using 
the style of the seal, the first discrimination level, which is a lower 
level in discrimination patterns, is set (S1). Next, the number of sheets 
of copies, that is, the number of output copies, is entered through the 
ten keys 49 in the operation panel 48 (S51). When the print key is 
depressed (S2), a document is scanned, and the inputted image is stored in 
the RAM 45 (S3). 
Successively, a seal detection is carried out to find whether or not the 
document image contains a seal, in the same manner as S5 of Embodiment 1 
(S21). If a seal is detected at S21, a judgement is made as to whether or 
not the seal is identical to any seal used in output-prohibited documents 
(S31). More specifically, the judgement is made as to whether or not the 
seal is identical to any seal of output-prohibited documents in its shape 
and size. 
If the judgement shows that the seal is identical to a seal of an 
output-prohibited document, a warning display is given on the liquid 
crystal display panel 50 in the operation panel 48, and the copying 
operation of the copying machine main body 26 is restricted (S52). 
Moreover, if the judgement is "NO" at S21 and S31, it is determined that 
the seal in question is neither a seal, nor any seal used in 
output-prohibited documents; therefore, the ordinary copying operation is 
carried out (S9). FIG. 19 illustrates the above-mentioned controlling 
operation. 
With this arrangement, the device makes a judgement that a document in 
question is important based on only the recognition of the seal; 
therefore, it is possible to prevent the copying machine from making 
unnecessarily large amount of copies. 
Moreover, the present embodiment may provide another arrangement, wherein: 
a seal is detected as a character in a document; a judgement is made as to 
whether the seal is a signet, a registered seal, a company's seal, or 
another seal; and the permissible number of output copies is restricted in 
accordance with the kind of the seal. In this case, as shown in FIG. 20, 
upon detection of a seal at S21, the kind of the seal is identified by 
using the kinds of seals, that is, signets, registered seals, and 
company's seals, that have been preliminarily stored in the seal-storing 
section 56 (S53). The judgement is made based on the size and style of the 
seal. 
Then, if the kind of the seal is identified as any kind of seals, that is, 
signets, registered seals, and company's seals, the number of output 
copies is restricted in accordance with the corresponding kind of the seal 
(S54). For example, the number is restricted to one copy for company's 
seals, to five copies for registered seals, and to ten copies for signets. 
Next, the copying operation is carried out under this restriction (S55), 
and is continued until the number of output copies reaches the restricted 
number of copies while comparing the current number of copies with the 
restricted number of copies (S56). When the restricted number of copies is 
exceeded, a warning display is given on the liquid crystal display panel 
50 in the operation panel 48, and the copying operation of the copying 
machine main body 26 is stopped (S57). FIG. 21 illustrates the 
above-mentioned controlling operation. 
With this arrangement, the device makes a judgement as to whether or not a 
document in question is important based on the kind, size and shape of the 
seal, and if the judgement is made as such, the copying operation is 
stopped so as not to make an unnecessarily large amount of copies, in 
accordance with the degree of importance. 
Further, it is possible to adopt another arrangement wherein: a seal is 
detected as a character in a document; a judgement is made as to whether 
or not the seal is one of the registered seals that are put on 
copy-permissible documents; and if the seal is not registered, a warning 
is given and the copying operation is stopped. 
In this case, as shown in FIG. 22, upon detection of a seal at S21, a 
judgement is made as to whether or not this seal is one of the seals that 
have been preliminarily registered in the seal-storing section 56 shown in 
FIG. 1, based on the size and style of the seal (S58). 
Next, if the seal is not a registered seal, a warning display is given on 
the liquid crystal display panel 50 in the operation panel 48, and the 
copying operation of the copying machine main body 26 is stopped (S57). 
Here, if the judgment is "NO" at S21 and S58, it is determined that the 
seal is neither a seal, nor a registered seal, and the copying operation 
is carried out (S9). FIG. 23 illustrates the above-mentioned controlling 
operation. 
With this arrangement, a judgement is made as to whether or not the copy of 
a document is permissible based on only the recognition of its seal; this 
makes it possible to prevent unnecessary copying operations. 
Moreover, it is possible to adopt another arrangement wherein: a seal is 
detected as a character in a document; a judgement is made as to whether 
or not the seal is one of the registered seals that are put on documents 
the copy of which is restricted in number; and if the seal is a registered 
one, the number of copies is restricted to a permissible number of copies 
that has been preliminarily determined. 
In this case, as shown in FIG. 24, after the first discrimination level has 
been set at S1, permissible numbers of copies are set in the seal-storing 
section 56 shown in FIG. 1 with respect to predetermined seals (S51). 
Thereafter, upon detection of a seal at S21 after the steps S2 and S3, a 
judgement is made as to whether or not this seal is one of the seals that 
have been preliminarily stored in the seal-storing section 56 based on the 
size and style of the seal (S59). 
Successively, if the seal is one of the registered seals, the predetermined 
permissible number is read from the seal-storing section 56 (S54). Then, 
the copying operation is carried out under this restriction (S55), and is 
continued until the number of output copies reaches the restricted number 
of copies (S56). When the restricted number of copies is exceeded, a 
warning display is given on the liquid crystal display panel 50 in the 
operation panel 48, and the copying operation of the copying machine main 
body 26 is stopped (S57). FIG. 25 illustrates the above-mentioned 
controlling operation. 
With this arrangement, a judgement is made as to the permissible number of 
copies for a document based on only the recognition of its seal; this 
makes it possible to prevent unnecessary copying operations. 
Furthermore, it is possible to adopt another arrangement wherein: a seal is 
detected as a character in a document; a judgement is made as to whether 
or not the seal is red; and if the seal is red, the copying operation is 
carried out after converting its color to black. 
In this case, as shown in FIG. 26, upon detection of a seal at S21, a 
judgement is made as to whether or not this seal is red (S61). Next, if 
the seal is red, the red color is converted into black (S62), and then the 
copying operation is carried out (S9). FIG. 27 illustrates the 
above-mentioned controlling operation. 
This arrangement makes it possible to supply copies that raise no problems 
for ordinary use while preventing counterfeit problems, by merely using 
the recognition of the seal. 
As described above, in the anti-counterfeiting device of the present 
invention for use in the digital copying machine, the character-detecting 
section 51, which is shown in FIG. 1 and functions as the seal detector, 
detects a seal from an inputted image that has been read from a document. 
Then, the output control section 57, which functions as the output 
restricter, conducts output restrictions in accordance with the detection 
of seal made by the character-detecting section 51 in such a manner that 
the number of output copies is restricted or the color conversion is made 
with respect to the output of image data. 
Therefore, the judgement is made as to whether or not a document in 
question is one of the output-prohibited documents by using only seals; 
this makes it possible to simplify the judgement and reduce the burden in 
the discrimination, thereby reducing the judging time. 
Moreover, since the output restrictions as to the number of output copies, 
the color conversion of output data, and other factors with respect to 
image data are conducted in accordance with the detection of seal made by 
the character-detection section 51, it is possible to reduce the 
possibility of losses due to counterfeit from the aspect of output 
restriction. 
The invention being thus described, it will be obvious that the same may be 
varied in many ways. Such variations are not to be regarded as a departure 
from the spirit and scope of the invention, and all such modifications as 
would be obvious to one skilled in the art are intended to be included 
within the scope of the following claims.