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BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus and method
thereof capable of detecting a specific image or a predetermined image
from an original image in a color printer, color copier, color facsimile
and so on, which outputs a color image, performing an output control of
the original image based on the result of detection.
Along the recent improvement of image quality, colorization, popularization
of an image processing apparatus, a specific original which is not
supposed to be duplicated (for example, securities/bank notes/confidential
documents) can be duplicated at such a high quality which is not
distinguishable from the original, resulting in fear of improper usage. In
order to prevent such duplication, in a copying machine such as a
full-color copier which outputs an image signal obtained by reading the
original at real time, the image data read once in several scanning
operations is compared with the image data of the specific originals, and
a particular pattern is added during latent image formation at the next
scanning of the original.
However, in an apparatus which performs full-color image processing and
outputs a read image at real time on one scanning, if control of the image
processing is modified at the end of scanning, it is impossible to prevent
the specific original, which has been already duplicated, from being
misused.
Furthermore, in an image forming apparatus which applies ink-jet technique
among color image forming apparatuses such as a color copier having high
image reproducibility, an image is formed by repeating the process such
that an ink-jet type recording head having a predetermined width to a
sub-scanning direction scans toward a main scanning direction, while a
recording medium is moved toward the sub-scanning direction. In comparison
with an electronic photography type apparatus, the image forming apparatus
having the above structure has an advantage when a large size original is
duplicated or it is constructed as a light-weight compact size.
However, as described above, along the improvement of quality of a formed
image, the problem arises in that the originals which should not be
duplicated are reproduced by using the above image forming apparatus.
These apparatuses are required to have a function to prevent the specific
originals from being forged from the social responsibility standpoint.
In order to prevent forming the specific originals, determination means for
determining the specific originals are needed. As such determination
means, there are techniques which are applied to a cash dispenser used in
financial institutions and applicable to the color image forming
apparatus.
In an image forming apparatus using electronic photography, the image can
be determined by prescanning an entire original image. However, in the
color image forming apparatus having a construction such that a recording
head scans to form the image, a general process is such that the reading
head having a predetermined width to the sub-scanning direction scans
toward the main scanning direction is repeated to read the entire image.
Accordingly, it takes a considerable amount of time for prescanning to
determine whether or not the original image is a specific original and the
throughput of image formation is much deteriorated.
In order to solve the above problems, there is a method to determine
whether or not the original image is a specific original successively.
The width of the recording head in the image forming apparatus having the
above arrangement is approximately 16 mm. Theoretically, it is possible to
have a wider head, however, this level is practical because of the cost of
production.
In this case, the image is read in the width of the recording head. In
order to determine a specific original accurately, the image of the width
approximately 100 mm is needed. Accordingly, when the specific original is
determined, several bands of the image (assumed the image formed by one
main scanning operation as one band) has already been formed.
Conventionally, a technique such that, in the case of the specific
original, a recording paper is rewound for a predetermined width and the
portion where the specific original has been recorded is printed in solid
color at the completion of the discrimination of the specific original.
However, in such a technique, when the power is shut down before the
recording paper is rewound, but after the determination has been
completed, a considerable amount of width of the specific original may
remain in the apparatus. Accordingly, a part of the duplication of the
specific original can be obtained by taking the recording paper out of the
apparatus.
Other methods for recognizing a specific original are as following:
When an image is formed by a frame sequential method, for example, the
original is read for one frame, and color separation is performed and cyan
component is first printed. Subsequently, the same original is read for
one frame and magenta component is printed over the same copying paper.
This operation is repeated for yellow and black components and a
full-color image is formed. Accordingly, when the specific original is
detected while the image is read for three frames, the black component
which is printed last of the four colors can be printed all over the
copying paper, thus, forgery can be prevented.
Furthermore, in a dot sequential type such that an image of four colors
such as Y, M, C, K is printed in every pixel and a full-color image is
formed in pixel sequence. When the original of being the specific original
is detected, a part of the specific original has been already duplicated.
Conventionally, counterfeit is prevented by printing over the partially
duplicated image.
However, in the dot sequential type, if copying operation is suspended
before the original is completely detected as being the specific original,
a part of the specific original may be duplicated and outputted.
Furthermore, in order to solve the above problems, the method such that
particular information such as a type of copying machine, serial number,
and manufacture date is coded and added to the image output in order to
trace and identify the used apparatus from the output image. More
particularly, in a binary recording method using the ink-jet type, it is
suggested that when recording is performed by similar tone reproduction, a
print dot is shifted in accordance with a code added at a predetermined
density and a print-dot space is adjusted.
However, in this method, when an image is formed by performing a plurality
of scanning operations using a print head having a plurality of nozzles, a
seam between the scanning operations appears when a code number is added
by shifting the print dot. This becomes outstanding where the dot starts
to shift because the print-dot space is adjusted within one band.
The detail is described with reference to FIGS. 54A and 54B. FIG. 54A shows
an example of the image when a code number is not added and a circle
denotes a print dot. FIG. 54B is an example of the image when the code
number is added to the image shown in FIG. 54A and the dot is shifted
backward. As shown in FIG. 54B, there is a defect such that the image is
seen as lacking a part of the image depending upon image.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an image
processing apparatus and method thereof capable of suppressing the
formation of a specific original which is prohibited from image formation
and minimizing the effect of the discrimination processing such that
whether or not an objective image is a specific original upon the
throughput of the image forming sequence.
According to the present invention, the foregoing object is attained by an
image processing apparatus having reading means for reading an original by
performing a scanning operation on the original in a predetermined
direction, and image formation means for forming an image onto a recording
medium, based on image information obtained by the scanning operations by
the reading means, by performing a scanning operation in the predetermined
direction, comprising: first image determination means for determining a
possibility that an image represented by the image information is a
predetermined image; means for interrupting an image formation by the
image formation means in a case where the first image determination means
determines that the image represented by the image information has the
possibility of being a predetermined image; and second image determination
means for determining whether or not the image represented by the image
information is a predetermined image based on the image information
obtained by successively scanning the original by the reading means, after
that the image represented by the image information has the possibility of
being a predetermined image is determined by the first image determination
means, wherein, in a case where the second image determination means
determines that the image represented by the image information is a
predetermined image, the image formation by the image formation means is
suspended, while in a case where the second image determination means
determines that the image represented by the image information is not a
predetermined image, the image formation by the image formation means is
restarted.
It is another object of the present invention to provide an image
processing apparatus capable of preventing improper usage of the copying
machine by coping with counterfeit of the specific originals.
According to the present invention, the foregoing object is attained by an
image processing apparatus which reads an original image, and sequentially
outputs image information based on the original image, comprising: first
image determination means for determining that an image represented by the
image information has a possibility of being a predetermined image; means
for interrupting an output of the image information, in a case where the
first image determination means has determined that an image represented
by the image information has the possibility of being a predetermined
image; and second image determination means for determining whether or not
the image represented by the image information is a predetermined image
based on the successively read image information, after it is determined
that the image represented by the image information has the possibility of
being a predetermined image by the first image determination means,
wherein, in a case where the second image determination means determines
that the image represented by the image information is a predetermined
image, the output of the image information is suspended, while in a case
where the second image determination means determines that the image
represented by the image information is not a predetermined image, the
output of the image information is restarted.
Furthermore, it is another object of the present invention to provide an
image processing apparatus capable of preventing generation of a seam on
the duplicated image by holding the border of dots between the scanning
operations when a code number to identify the apparatus is added.
According to the present invention, the foregoing object is attained by an
image processing apparatus which records an image for a single frame by
performing a plurality of scanning operations in a predetermined
direction, comprising: means for inputting predetermined data; addition
means for adding predetermined information to the image based on the
predetermined data; and control means for controlling an addition of the
predetermined information by the addition means in a border portion formed
by the plurality of scanning operations.
Other features and advantages of the present invention will be apparent
from the following description taken in conjunction with the accompanying
drawings, in which like reference characters designate the same or similar
parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated and constitute a part of
the specification, illustrate embodiments of the invention and, together
with the description, serve to explain the principles of the invention.
FIG. 1 is a perspective diagram illustrating a digital color copier
according to a first embodiment of the present invention;
FIG. 2 is a cross sectional view schematically illustrating the internal
construction of the digital color copying machine of FIG. 1;
FIG. 3 is a diagram illustrating the construction of a portion in the
vicinity of the scanning carriage 34 according to the first embodiment;
FIG. 4 is a diagram illustrating an internal mechanism of a scanner 1
according to the first embodiment;
FIG. 5 is a diagram for explaining the reading operation at a book mode and
sheet mode according to the first embodiment;
FIG. 6 is a block diagram illustrating the construction of a control system
in the digital color copier according to the first embodiment;
FIG. 7 is a block diagram illustrating the construction of control of a
main image processor 106 of the first embodiment;
FIG. 8 is a flowchart illustrating a copy sequence in the first embodiment;
FIG. 9 is a continuation flowchart illustrating a copy sequence in the
first embodiment;
FIG. 10 is a diagram for explaining the copy sequence in the first
embodiment;
FIG. 11 is a block diagram illustrating an example of the construction of
scanner control according to a second embodiment;
FIG. 12 is a flowchart for explaining the operation of the scanner of the
second embodiment;
FIG. 13 is a block diagram illustrating an example of the construction of a
printer control according to the second embodiment;
FIG. 14 is a flowchart for explaining the operation of the printer of the
second embodiment;
FIG. 15 is a block diagram illustrating the construction of the digital
color copier of the third embodiment;
FIG. 16 is a timing chart of the image between circuit blocks shown in FIG.
15;
FIG. 17 is a block diagram illustrating the construction of an image
determination unit 3123 according to a third embodiment;
FIG. 18 is a diagram for explaining a processing method of a
binary-to-multivalue conversion unit 802 according to the third
embodiment;
FIG. 19 is another diagram for explaining a processing method of a
binary-to-multivalue conversion unit 802 according to the third
embodiment;
FIG. 20 is a diagram for explaining a processing method of a
binary-to-multivalue conversion unit 802 according to the third
embodiment;
FIG. 21 is a diagram for explaining a method for multivalued transform by
thinning image data in the third embodiment;
FIG. 22 is a block diagram illustrating the construction of an integrator
805 according to the third embodiment;
FIG. 23 is a diagram of an example of input/output of the integrator 805
according to the third embodiment;
FIG. 24 is a diagram of another example of input/output of the integrator
805 according to the third embodiment;
FIG. 25 is a diagram of an example of the processing result according to
the third embodiment;
FIG. 26 is a diagram of an example of count value according to the third
embodiment;
FIG. 27 is a diagram of another example of count value according to the
third embodiment;
FIG. 28 is a diagram for explaining the relationship between scanning and a
threshold according to a modified example of the third embodiment;
FIG. 29 is a side view showing a general internal construction of an image
scanning body according to a fourth embodiment of the present invention;
FIG. 30 is a block diagram illustrating the circuit construction of the
image scanner 4201 according to the forth embodiment;
FIG. 31 is a block diagram illustrating the construction of a determination
circuit 409 according to the fourth embodiment;
FIG. 32 is a diagram illustrating the construction of a thinning circuit
according to the fourth embodiment;
FIG. 33 is a diagram illustrating the construction of a frequency-dividing
circuit according to the fourth embodiment;
FIG. 34 is a timing chart of the main scanning direction in the fourth
embodiment;
FIG. 35 is a diagram illustrating input/output of the integrator 4306
according to the fourth embodiment;
FIG. 36 is a block diagram illustrating the construction of a comparator
module 4308 according to the fourth embodiment;
FIG. 37 is a block diagram illustrating the construction of an output
controller 408 according to the fourth embodiment;
FIG. 38 is a block diagram illustrating the construction of the image
scanner according to the modification 1 of the fourth embodiment;
FIG. 39 is a block diagram illustrating the construction of the image
scanner according to the modification 2 of the fourth embodiment;
FIG. 40 is a block diagram illustrating the construction of the image
scanner according to the modification 3 of the fourth embodiment;
FIG. 41 is a diagram illustrating the construction of the control signal
forming circuit according to the modification 4 of the fourth embodiment;
FIG. 42 is a flowchart for explaining the operation at the image signal
output side according to the modification 5 of the fourth embodiment;
FIG. 43 is a flowchart for explaining the operation at the image signal
input side according to the modification 5 of the fourth embodiment;
FIG. 44 is a flowchart for explaining the processing procedure of a
communication control signal according to the modification 6 of the fourth
embodiment;
FIG. 45 is a block diagram illustrating the internal construction of the
image processing apparatus according to the fifth embodiment of the
present invention;
FIG. 46 is a timing chart of a part of the control signal in printing of
the fifth embodiment;
FIG. 47 is a diagram illustrating a model of the timing of FIG. 46;
FIGS. 48A and 48B are block diagrams illustrating the detailed construction
of a print-dot corrector 5101 according to the fifth embodiment;
FIG. 49 is a timing chart of code data and determination signal;
FIG. 50 is a diagram illustrating the dot arrangement according to the
fifth embodiment;
FIG. 51 is a timing chart of the signal according to a dot interval counter
5328 according to the fifth embodiment;
FIG. 52 is a diagram illustrating area information which is written in a
holder RAM 5106 for joint retaining according to the fifth embodiment;
FIG. 53 is a block diagram illustrating the construction according to the
image shifting according to the modification 1 of the fifth embodiment;
and
FIGS. 54A and 54B are diagrams illustrating a conventional dot state where
a code number is added.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in
detail in accordance with the accompanying drawings.
Copying machines will be described as embodiments of the present invention,
however, this does not impose a limitation upon the present invention, for
the present invention is applicable also to any other kind of apparatus
such as a simple image scanner and a printer. In the present invention,
the possible counterfeits include bank notes, securities, and originals of
confidential documents.
<The First Embodiment>
FIG. 1 is a perspective diagram illustrating a digital color copying
machine according to a first embodiment of the present invention.
The digital color copying machine is composed of two major portions. The
upper portion of the copying machine shown in FIG. 1 is comprised of a
color image scanner 1 (hereinafter referred to as "scanner") for reading
an image of original document and outputting digital color image data and
a controller 2 for performing various image processing operations of the
digital color image data stored in the scanner 1 and having a processing
function such as an interface function with external apparatus.
The lower portion of the copying machine shown in FIG. 1 is a printer 3 for
recording the color digital image signal outputted from the controller 2
to a recording paper.
The above two portions can be separated from each other and they can be set
remotely by extending a connection cable.
FIG. 2 is a cross sectional view schematically illustrating the internal
construction of the digital color copying machine of FIG. 1.
An image of original placed on an original glass table 17, a projected
image formed by a projector, or the image of a sheet-like original
document fed by a feeding mechanism 12 is read by an exposure lamp 14,
lens 15, and image sensor 16 by CCD capable of full-color reading of a
line image. The scanner 1 and controller 2 perform various image
processing operations, and a printer 3 records the image to a recording
paper.
In FIG. 2, the recording paper is selectively supplied from a paper feeding
cassette 20 containing small-regular-size (A4 to A3 size according to the
embodiment) cut-sheets or a roll paper 29 for recording information to
large size (A2 to A1) recording paper.
Furthermore, paper feeding from outside of the apparatus (manual paper
feeding) is enabled by feeding cut-papers one by one from an manual
feeding port 22 along a paper feeding cover 21. Pick-up rollers 24 are
rollers for feeding cut-papers one by one from the paper feeding cassette
20, and the fed cut-paper is conveyed to first paper feeding rollers
(first roller) 26 via cut-paper feeding rollers 25. The roll paper 29 is
conveyed by roll-paper feeding rollers 30, cut by a cutter 31 into a
predetermined length, and further conveyed to the first rollers 26 by a
manual feeding rollers 32. Similarly, the recording paper inserted from
the manual feeding port 22 is conveyed to the first rollers 26 by the
manual feeding rollers 32.
The pick-up rollers 24, cut-paper feeding rollers 25, roll-paper feeding
rollers 30, first rollers 26, and manual feeding rollers 32 are driven by
a paper feeding motor (e.g. a CD servo motor, but not shown) and their
rotations can be turned on/off by electromagnetic clutches provided for
the rollers.
When the printing operation is started by the instruction from the
controller 2, the recording paper selected and fed through either of the
above paper feeding passages is conveyed to the first rollers 26. In order
to prevent a skew of the recording paper, a paper loop of the recording
paper is formed by a predetermined quantity and the first rollers 26 are
turned on to rotate. Then, the recording paper is conveyed to second paper
feeding rollers (second rollers) 27.
Between the first rollers 26 and second rollers 27, in order to accurately
perform paper feeding between these rollers, the recording paper is
slackened for a predetermined quantity to form a so-called buffer. A
buffer quantity detection sensor 33 serves as a sensor to detect quantity
of the buffer. Since the buffer of the recording paper is always formed
during its conveyance, the load which acts on the paper feeding rollers 28
and second rollers 27, when large size recording paper is conveyed, can be
reduced so that an accurate paper feeding operation can be performed.
When printing is performed by the recording head 37, a scanning carriage 34
on which the recording head 37 is mounted is reciprocated by a scanning
motor 35 on a carriage rail 36. In the returning scanning operation, the
recording paper is conveyed for the predetermined quantity by the paper
feeding rollers 28. During this operation, it is controlled so that a
predetermined quantity of the buffer is always maintained by the paper
feeding motor, while the upper drive system is controlled by the buffer
quantity detection sensor 33.
The printed recording paper is received by a copy receiving tray 23 and the
sequential printing operation ends.
FIG. 3 is a diagram illustrating the construction of a portion in the
vicinity of the scanning carriage 34 according to the first embodiment.
In FIG. 3, a paper feeding motor 40 serves as a driving power source for
intermittently feeding the recording paper in the sub-scanning direction,
and for driving the second rollers 27 via the paper feeding rollers 28 and
a second paper feeding clutch (second roller clutch) 43. The scanning
motor 35 serves as a driving power source which drives the scanning
carriage 34 via a scanning belt 42 in the main scanning direction
designated by arrows A and B. Since the paper feeding operation must be
accurately controlled in this embodiment, pulse motors are used for the
paper feeding motor 40 and scanning motor 35. When the recording paper
reaches the second rollers 27, the second roller clutch 43, and the paper
feeding motor 40 are respectively turned on. As a result, the recording
paper is conveyed on a platen 39 to the paper feeding rollers 28.
The recording paper is detected by a paper detection sensor 44 provided on
the platen 39 and sensor information is utilized for position control and
jam control.
When the recording paper reaches the paper feeding roller 28, the second
roller clutch 43 and paper feeding motor 40 are respectively turned off.
As a result, a sucking operation is performed from the inside of the
platen 39 by a vacuum motor (not shown), and the recording paper is
contacted with the surface of the platen 39.
Prior to performing the image recording operation onto the recording paper,
the scanning carriage 34 is moved to a position at which a home position
sensor 41 is disposed, so that the forward scanning operation is performed
in the direction designated by the arrow A. In this forward scanning
operation, inks for cyan (C), magenta (M), yellow (Y), black (BK) are
respectively discharged from the recording head 37 at the predetermined
position. When an operation of recording the image by a predetermined
length has been completed, the scanning carriage 34 stops, and starts to
move in the direction designated by the arrow B, thus returns to the
position at which the home position sensor 41 is located. During the
returning directional scanning operation, the paper feeding motor 40
drives the paper feeding rollers 28 so that the paper feeding operation by
the length which is recorded by the recording head 37 is performed in the
direction designated by an arrow C.
In the embodiment, the recording head 37 is comprised of the four ink-jet
nozzles where 256 nozzles are assembled for each Y, M, C, BK.
When the scanning carriage 34 is stopped at a home position which is
detected by the home position sensor 41, an operation of recovering the
recording head 37 is performed. The aforementioned recovery operation is
performed to stable the recording operation by preventing irregular
discharge at the time of the start of discharge due to change in the
viscosity of ink left in the nozzle of the recording head 37. In this
recovery operation, pressure is applied to each nozzle in the recording
head 37 and an idle discharge of ink from each nozzle is performed under
the previously programmed conditions such as the time when the recording
paper is fed, the temperature in the apparatus, and the time when the
discharge is executed.
The image recording over the entire recording paper is performed by
repeating the above operations.
The operation of the scanner 1 is described below.
FIG. 4 is a diagram illustrating the internal mechanism of the scanner 1
according to the first embodiment.
In FIG. 4, a CCD unit 18 is a unit comprising of a CCD 16 and lens 15, and
is moved on a rail 54 by a main-scanning directional drive system
comprising of a main scanning motor 50 secured to the top surface of the
rail 54, pulleys 51 and 52, and a wire 53, so that it reads the image on
the original glass table 17. A light shielding plate 55 and home position
sensor 56 are used for the position control when the CCD unit 18 is moved
to the main scanning position in a correction area 68.
The rail 54 is placed on other rails 65 and 69 and moved by a sub-scanning
directional drive system comprising of a sub-scanning motor 60, pulleys
67, 68a, 71, 76, shafts 72 and 73, wires 66 and 70. A light shielding
plate 57 and home position sensors 58, 59 are used for the position
control when the rail 54 is moved to the sub-scanning home scanning
position in a book mode where an original document such as a book placed
on the original glass table 17 is read and a sheet mode where a sheet
original document is read.
Sheet feeding motor 61, sheet feeding rollers 74, 75, pulleys 62, 64, and a
wire 63 form a mechanism for feeding the sheet original. This mechanism is
disposed on the original glass table 17 to feed the sheet original
document downwards placed on the table by a predetermined quantity by the
sheet feeding rollers 74 and 75.
FIG. 5 is a diagram for explaining the reading operation in the book mode
and sheet mode according to the first embodiment.
In the book mode, the CCD unit 18 is moved to a book mode home position
(book mode HP) in a correction area 68 shown in FIG. 5, and an operation
of reading the entire surface of the original document placed on the
original glass table 17 is started.
Prior to performing the operation of scanning the original document,
parameters required to perform a shading correction operation, a black
level correction operation, and color correction operation are set in the
correction area 68. Then, the scanning to the main scanning direction is
started by the main scanning motor 50 in the direction designated by the
arrow. When an operation of reading an area 1 has been completed, the
rotation of the main scanning motor 50 is reversed and the sub-scanning
motor 60 is driven to move the sub-scanning direction to the area 2 of the
correction area 68. Subsequently, similar to the main scanning of the area
1, the processing such as shading correction, black level correction,
color correction are performed if necessary, and an operation of reading
the area 2 is performed.
The reading operation over the entire surface areas 1-7 is executed by
repeating the above scanning. When the area 7 has been read, the CCD unit
18 is again returned to the book mode.
In the embodiment, since the original glass table 17 is able to read an
original document the size of which is A2 or smaller, the operations
described above must be performed more frequently. However, the
description is simplified to make the operation understood easily.
In the sheet mode, the CCD unit 18 moves to a sheet mode home position
(sheet mode HP) to repeatedly read area 8 of the sheet original document
by intermittently rotating the sheet feeding motor 61, so that the entire
surface of the sheet original document is read.
Prior to scanning the original document, the processings such as shading
correction, black level correction, color correction are performed by the
correction area 68. Subsequently, the main scanning motor 50 executes the
main scanning directional scanning in a direction designated by an arrow
in FIG. 5. When the area 8 has been read by the forward scanning
operation, the rotation of the main scanning motor 50 is reversed and the
returning directional scanning is executed. During the returning
directional scanning, the sheet feeding motor 61 is driven to move the
sheet original document in the sub-scanning direction. Subsequently, the
similar operation is repeated and the entire surface of the sheet original
document is read.
As described above, if the reading operation is an equal magnification
reading operation in a copying process, the area read by the CCD unit 18
is a considerably wide area shown in FIG. 5. This is because the digital
color copying machine of the embodiment includes a variable magnification
function for enlargement and reduction. More particularly, when
50%-reduction is performed, since a region recorded by the recording head
37 is fixed to 256 bits for one time, image information of at least a
region 512 bits which is twice the above bits must be used. Accordingly,
the scanner 1 contains a function capable of reading and outputting image
information of an arbitrary image region by one main scanning reading
operation.
(System Structure)
Processing and controlling of an image signal in the control system of the
digital color copier of the embodiment is described. FIG. 6 is a block
diagram illustrating the control system structure in the digital color
copying machine of the embodiment.
In FIG. 6, numeral 100 is a main CPU which controls the overall operation
of the copying machine. The main CPU 100 is connected to a printer control
CPU 102 for controlling the operation of the printer, reader control CPU
104 for controlling the reading operation, a main image processor 106 for
processing the image forming operation, an operation unit 108 for
processing various inputs from an operator. The printer control CPU 102
and reader control CPU 104 respectively control the printer 120 and reader
112. The CPUs 102 and 104 serve as a slaves with respect to the main CPU
100, a master.
The printer control CPU 102 is connected to a printer driving system 114
for controlling the input operation to the printer 120.
The reader control CPU 104 is connected to an input system image processor
116 for performing the correction processing such as such as a shading
correction, a color correction, and .gamma. correction required for the
reading system 118 and a reader drive system 118 for controlling the input
to the reader 112.
Furthermore, the image sensor 126 comprising a CCD is connected to the
input system image processing unit 116 which is connected to the main
image processor 106.
The reader 112 is provided with the main CPU 100, reader control CPU 104,
main image processor 106, operation unit 108, input system image processor
115, reader drive system 118, and image sensor having a CCD line sensor.
The printer 120 is provided with the printer control CPU 102,
synchronizing memory 110, recording head 156, and printer drive system
114.
(Image Discrimination Processing)
The main image processor 106 is described in detail. FIG. 7 is a block
diagram illustrating the control structure of the main image processor
106.
An image signal from the input system image processor 116 is transmitted to
a black extraction unit 201. Black data is extracted from minimum values
of C, M, Y image components. The image signal is also transmitted to an
image discrimination unit 200. In the image discrimination unit 200,
whether or not the input image signal is that of a specific original which
is prohibited from image formation (hereinafter referred to as a "specific
original") is discriminated by a well-known pattern recognition method.
Numeral 202 is an output masking unit for performing an output masking
processing to the image, numeral 203 is a .gamma. correction unit for
performing a .gamma. correction, and numeral 204 is a binarization
processor for binarizing a multivalue image signal. The image signal which
is binarized in the binarization processor 204 is transmitted to the
printer 20. Parameters needed for each processor (200-204) are set by the
main CPU 100 via a data bus 205. The result of discrimination in the image
discrimination unit 200 is also transmitted to the main CPU 100 via the
data bus 205. The image signal is transmitted to the printer 120, as image
data via each processor (200-204), where an image is formed based on the
image data.
The detail of the copying sequence which is executed in the main CPU 100,
printer control CPU 102, reader control CPU 104 is described with
reference to FIGS. 8 and 9.
When a start key (not shown) provided in the operation unit 108 is pressed,
a copying sequence task program is called out of a program memory (not
shown), the main CPU 100 proceeds the process to step S1 of FIG. 8.
At step S1, data required for an initial setting is transmitted to the
reader control circuit 104 and the initial setting of the reader 112 is
performed. When this setting ends, the process proceeds to step S2 where
the data required for the initial setting is transmitted to the printer
control CPU 102 and the initial setting of the printer 120 is performed.
When the above processings end, the main CPU 100 proceeds the process to
step S3 where the image processing parameters are set. Data required for
the image discrimination unit 200, output masking unit 202, and .gamma.
correction unit 203 are set. At step S4, the image discrimination unit 200
is activated to start image discrimination.
At step S5, if a state where the reader and printer are ready for main
scanning operation is confirmed, the process proceeds to step S6 where the
main scanning operation is started. During the scanning operation in the
main scanning direction, the image discrimination unit 200 monitors an
input image signal and discriminates the possibility if the input image
signal is that of a specific original. When the scanning operation ends at
step S7, the process proceeds to step S8. At step S8, the main CPU 100
reads the data from the image discrimination unit 200 and discriminates
the possibility of the input image signal being a specific original. If
the possibility is low, the process proceeds to step S9 where whether or
not the image formation for all bands has been completed, that is, the
coping operation has been completed is discriminated. If YES, the copying
sequence ends, while if NO, the process proceeds to step S10 where a
scanning operation in the sub-scanning direction is performed in the
reader 112 and printer 120. Subsequ | | |
