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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image combining apparatus, for use in a
digital copying machine. The invention relates, particularly, to an image
combining apparatus for combining divided images obtained when reading a
large size document.
2. Discussion of Background
Generally speaking, in a digital copying machine that reads an image of a
document by photo-electric conversion, there is an apparatus for combining
an image reading memory and an automatic document conveying device which
results in faster copying. Such an apparatus is disclosed in Japanese
Patent Laid-Open Publication No. 81563/1990.
Moreover, as disclosed in Japanese Patent Laid-Open Publications Nos.
129660/1989 and 129662/1989, when images in plural documents are read and
combined with one another, a scanner reads each image in only desired
areas in each of the plural documents. As a result a reduction of memory
capacity is achieved.
In these conventional apparatuses, however, the apparatus disclosed in
Japanese Patent Laid-Open publication No. 81563/1990 does not refer to
image combining for plural documents. On the other hand, in the
apparatuses as disclosed in Japanese Patent Laid-Open Publications Nos.
129660/1989 and 129662/1989, a reading sensor moves to the desired areas
in the documents by an input area signal. Alternatively, image data other
than the desired area are masked. As a result, these alternatives provide
complicated structures and difficult operations.
There is thus a need for an image combining apparatus for recombining into
a single image, divided images obtained when reading a large size document
where the image scanning area is less than the area of the large document.
The present invention fills that and other needs.
SUMMARY OF THE INVENTION
Accordingly, one object of this invention is to provide an image combining
apparatus which combines images through the use of a simple apparatus and
operation.
Another object of this invention is to provide an image combining apparatus
which reads documents that are larger than the size of the reading
apparatus.
These and other objects and advantages of are achieved by the present
invention which provides for combining a magnifier with an image holding
memory. In accordance with one aspect of the invention, an image
combination is achieved briefly and efficiently by adjusting a
magnification ratio the size of the image represented by the scanning
signal to fit within the storage capacity of the image holding memory. In
accordance with another aspect of the invention, an image combination is
also achieved briefly and efficiently by compressing image data by a
binarization processor.
BRIEF DESCRIPTION OF THE DRAWINGS
In describing preferred embodiments of the present invention illustrated in
the drawings, specific terminology is employed for the sake of clarity.
However, the invention is not intended to be limited to the specific
terminology so selected, and it is to be understood that each specific
element includes all technical equivalents which operate in a similar
manner to accomplish a similar purpose.
A more complete appreciation of the invention and the many attendant
advantages thereof will become readily apparent from the following
detailed description, particularly when considered in conjunction with the
drawing in which:
FIG. 1 is a block diagram of the first embodiment of the present invention;
FIG. 2a is a schematic diagram of a one color printer;
FIG. 2b is a schematic diagram of a four color printer;
FIG. 3 is a block diagram of a image holding device in FIG. 1;
FIG. 4 is a functional diagram of an operation panel for use with the
embodiment of FIG. 1;
FIG. 5a is a schematic diagram showing the main and sub-scanning directions
of a document;
FIG. 5b shows the clock signals associated with the scanning of FIG. 5a;
FIG. 6 is a block diagram of the address controller shown in FIG. 3;
FIG. 7 shows schematically the several ways images may be combined in
accordance with the first embodiment;
FIG. 8 shows schematically how to scan different portions of a document;
and
FIG. 9 shows a block diagram of an image holding memory for a second
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a conventional scanner 101 has a desired reading size or image
area, for example A3 size. A conventional image processor 102 processes
shading correction, gamma correction, and gradation correction of scanning
signals (conversion from Red, Green, Blue signals to Yellow, Magenta, Cyan
signals in case of color signal processing). A conventional magnifier 103
in image processor 102 enlarges and reduces the image read by the scanner
101. The signal output from the image processor 102 is fed to the input of
a conventional printer 105 directly on data bus 110 as shown in FIG. 1 or
by way of an image holding device in which the signal is held and then
read on data bus 110 as shown in FIG. 3. A controller 106 controls the
scanner 101, the image processor 102 (especially the magnifier), the image
holding device 104, and the printer 105 by variable data input from the
operation panel 107 by an operator.
Referring now to the figures, preferred embodiments of the invention will
be described.
In the printer 105, for example, an image with a maximum A3 size is printed
on a sheet of paper. In the case where a color image is printed by one
drum 201a as shown in FIG. 2(a), an image of a document is scanned four
times by the scanner 101 and then each color component of Red, Green,
Blue, and Black is drawn. Then, the data of Yellow, Magenta, Cyan, and
Black are converted from Red, Green, Blue, and Black. After these
converted data are stored in a memory 202a after each scan, the data are
read and developed by the drum 201a. Also in the case where the color
image is printed on a sheet of paper by four drums 201b which are
installed in each desired position, the image of the document is scanned
once by the scanner 101 and then each color component of Red, Green, Blue,
and Black is drawn. Then, the data of Yellow, Magenta, Cyan, and Black are
converted from Red, Green, Blue, and Black. These converted data are
stored after being delayed in accordance with the installation interval of
the four drums and they are read and then developed by the drums 202b. As
shown in detail in FIG. 3, the image holding device has an address
controller 301, a memory 302 and a data controller 303. A line memory,
which is same as the memory 202a, is used as the memory 302 in the case of
the one drum system. On the other hand, memories with a capacity the same
as the memory 202b, are used in the case of the four drum system.
As shown in detail in FIG. 4, the operation panel 107 has a start key 401
for starting a scanning operation by the scanner 101 and numeral keys for
input of the document size, the sheet size, magnification ratio, copy
quantity and etc., and a liquid crystal panel for display of helpful
information. The many kinds of input data to the operation panel are
processed in the controller 106. The controller generates a main scanning
clock signal CLK, a sub-scanning clock signal (a horizontal synchronizing
signal) LSYNC and a start pulse START in accordance with the reading
direction of the scanner 101 as shown in FIG. 5(a), and outputs them to
the address controller 301, the memory 302 and the data controller 303. It
also generates a counter up/down signal U/D and a memory read/write signal
R/W. The U/D signal is output to the address controller 301 and the R/W
signal is output to the memory 302.
The scanner 101, the processor 102 including the magnifier 103, the printer
105, the controller and the operation panel 107 as described above are
basically same as those described in U.S. Pat. No. 5,122,833, incorporated
by reference herein, U.S. patent application No. 870,453, U.S. Pat. No.
5,325,209, also incorporated by reference herein, and those of a digital
copying machine model number DS320 made by Ricoh Company, Ltd. of Japan,
the present assignee.
Next, referring to the block diagram shown in FIG. 6 the address controller
301 is described.
The main scanning clock signal CLK, the counter up/down signal U/D, the
reading or writing start position X1 of X direction of the memory from the
controller 106 are input to the up/down counter 501 of the main scanning
direction (X direction) from the controller 106. Also an output signal
from a comparator 503 and the sub-scanning signal LSYNC are input to the
LOAD(LD) terminal of the counter 501 through an OR gate 510. The output
signal therefrom is input to the comparator 503 of X direction and an
address terminal of the memory 302. The output signal from the counter 501
and the reading or writing end position X2 of X direction of the memory
from the controller 106 are input to the comparator 503. The output signal
therefrom is input to the counter 501 through the OR gate 510.
Similarly, the sub-scanning clock signal LSYNC, the counter up/down signal
U/D, the reading or writing start position Y1 of Y direction of the memory
from the controller 106 are input to a up/down counter 502 of the
sub-scanning direction (Y direction) from the controller 106. Also an
output signal from a comparator 504 and a start pulse START are inputted
to LOAD(LD) terminal of the counter 502 through an OR gate 512. The output
signal therefrom is input to the comparator 504 of Y direction and the
address terminal of the memory 302. The output signal from the counter 502
and the reading or writing end position Y2 of Y direction of the memory
from the controller 106 are input to the comparator 504. The output signal
therefrom is input to the counter 502 through the OR gate 512. Moreover, a
memory plane indicating signal NUM from the controller 106 is input to the
memory 302 and D terminal of the memory 302 is connected to the data
controller 303.
Next, the operation of the image holding device is described. In the
up/down counter 501 of the main scanning direction (X direction), the main
scanning clock signal CLK is counted up or down from the writing or
reading start position of the X direction in the memory 302. Then in the
comparator 503, when the count value of the counter 501 equals the writing
or reading end position X2 of the X direction, the count value in counter
501 is loaded into comparator 503. Then the counter 501 outputs address
signals, which are signals from the start position to the end position, to
the memory 302 as shown in FIG. 7.
Similarly, in the up/down counter 502 of the sub-scanning direction (Y
direction), the sub-scanning clock signal LSYNC is counted up or down from
the writing or reading start position of the Y direction in the memory
302. Then in the comparator 504, when the count value of the counter 502
equals the writing or reading end portion Y2 of the Y direction, the count
value in counter 502 is loaded into comparator 504. Then the counter 502
outputs address signals, which are signals from the start position to the
end position, to the memory 302 as shown in FIG. 7. The reading or writing
from X1 to X2 and from Y1 to Y2 finishes as described above and then "0"
of the memory plane indicating signal is changed into "1" and the above
operation repeats. This operation is repeated the same number of times as
there are divisions of the documents. For the first embodiment, the
operation is repeated four times because the large document is divided
into quarters.
Next, referring to FIG. 6, 7, 8, the operating sequence of the first
preferred embodiment is described. For purposes of describing the
preferred embodiment, the following conditions are assumed. The size of
the document is, for example A1. The maximum reading size of the scanner
101 is, for example A3, which is smaller than the size of the A1 document.
The capacity size of the memory 302, which is smaller than the size of the
A1 document is, for example A4. The maximum output size of the printer
which is larger than the memory size is, for example A3.
Initially, the document size A1 is input from the operator panel 107 to the
controller 106. The controller 106 sets (1) the magnification ratio
(memory size)/(document size)=A4/A1=1/8, (2) the start position
(X1,Y1)=(105 mm,0 mm) for writing the image data of the quarter upper
right-hand area of the document into the quarter upper right-hand area of
the memory 302, (3) the end position (X2,Y2)=(210 mm,149 mm) for that, (4)
the count up/down signal U/D=1 (count up) and (5) the read/write signal
R/W=0 (write). At this time, the document is set accurately on the
determined position of the glass board of the copying machine for
scanning. In other words, the edge of the document is set along a
reference line on the glass board for scanning, so that the quarter upper
right-hand area of the document can be read as shown in FIG. 8(a). Then
the start key 401 is pushed, the image of the A3 size- quarter upper
right-hand area of the A1 size-document is read by the scanner 101. Then
it is reduced to A6 size, which is the magnification ratio=1/8 of the size
A3 of the scanner 101, by the magnifier 103. Then the A6 size-reduced
image data are written into the quarter upper right-hand area of the
memory 302.
Second, the document is set on the glass board for scanning as described
above so that the quarter lower right-hand area of the document can be
read as shown in FIG. 8(b), then the start key is pushed. The control
means 106 sets (1) the magnification ratio (memory size)/(document
size)=A4/A1=1/8, (2) the start position (X1,Y1)=(105 mm,149 mm) for
writing the image data of the quarter lower right-hand of the document
into the quarter upper right-hand area of the memory 302, (3) the end
position (X2,Y2)=(210 mm,298 mm) for that, (4) the count up/down signal
U/D=1 (count up) and (5) the read/write signal R/W=0 (write). At this
time, the image of the A3 size- quarter lower right-hand area of the A1
size-document is read by the scanner 101, then it is reduced to A6 size,
which is the magnification ratio=1/8 of the size A3 of the scanner 101, by
the magnifier 103. Then the A6 size-reduced image data are written into
the quarter lower right-hand area of the memory 302. As a result, the
total image data of A6 size are stored in the memory 302.
Third, the document is similarly set on the glass board for scanning so
that the quarter upper left-hand area of the document can be read as shown
in FIG. 8(c). Now it is set as turned over at 180 degrees of FIGS. 8(a)
and 8(b). Then the start key is pushed. The control means 106 sets (1) the
magnification ratio (memory size)/(document size)=A4/A1=1/8, (2) the start
position (X1,Y1)=(105 mm,149 mm) for writing the image data of the quarter
upper left-hand of the document into the quarter upper left-hand area of
the memory 302, (3) the end position (X2,Y2)=(0 mm,0 mm) for that, (4) the
count up/down signal U/D=0 (count down) and (5) the read/write signal
R/W=0 (write). At this time, the image of the A3 size- quarter upper
left-hand area of the A1 size-document is read by the scanner 101, then it
is reduced to A6 size, which is the magnification ratio=1/8 of the size A3
of the scanner 101, by the magnifier 103. Then the A6 size-reduced image
data are written into the quarter upper left-hand area of the memory 302.
Finally, the document is similarly set on the glass board for scanning so
that the quarter lower left-hand area of the document can be read as shown
in FIG. 8(c), then the start key is pushed. The control means 106 sets (1)
the magnification ratio (memory size)/(document size)=A4/A1=1/8, (2) the
start position (X1,Y1)=(105 mm,298 mm) for writing the image data of the
quarter lower left-hand of the document into the quarter lower left-hand
area of the memory 302, (3) the end position (X2,Y2)=(105 mm,298 mm) for
that, (4) the count up/down signal U/D=0 (count down) and (5) the
read/write signal R/W=0 (write). At this time, the image of the A3 size-
quarter lower left-hand area of the A1 size-document is read by the
scanner 101, then it is reduced to A6 size, which is the magnification
ratio=1/8 of the size A3 of the scanner 101, by the magnifier 103. Then
the A6 size-reduced image data are written into the quarter lower
left-hand area of the memory 302.
As a result, the whole image of the A1 size-document is reduced by the
magnification ratio 1/8 and stored in A4 size-memory 302. Now in FIGS.
8(c) and 8(d), the reason why the document is turned over 180 degrees from
the document position in FIGS. 8(a) and 8(b) is that hinges for a document
press board that covers the glass plate prevents the document from being
scanned in the same orientation as FIGS. 8a and 8b. If the document press
board is removed, the document can be read by moving parallel around the
glass plate.
Writing as described above is completed, then the controller 106 sets (1)
the start position (X1,Y1)=(0 mm,0 mm) for reading the memory 302, (2) the
end position (X2,Y2)=(200 mm,298 mm) for that, (3) the count up/down
signal U/D=1 (count up) and (4) the read/write signal R/W=1 (read). At
this time, the A4 size-combining image data are read from the memory 302
and printed on the A4 size-a sheet of paper as shown in FIG. 7(a).
Thus, according to the above, for the first embodiment, the large size
document, for example A1 size, can be combined and printed by the
magnifier 103 and the image holding device 104 even though the scanner
size, for example A3, is smaller than the size of the large document. Now
in this embodiment the A1 size-document is reduced to A4 size which is the
size of the memory and the reduced document is output by the printer 105
the size of which is larger than that of the memory 302. On the contrary,
if the size of the memory is larger than or equal to the size of the
printer, the magnification ratio is (the maximum size of the printer)/(the
size of the document). That is,
(a) if (the size of the memory)<(the size of the maximum size of the
printer),
the magnification ratio=(the size of the memory)/(the size of the document)
(b) if (the size of the memory)>=(the size of the maximum size of the
printer),
the magnification ratio=(the maximum size of the printer)/(the size of the
document).
In addition, in the present embodiment, the position of the A3 size-divided
image is recovered when the image data are written into the memory, but
the recovery of the divided image may be done when the data are read from
the memory.
Next a second embodiment of the present invention is described. In this
embodiment, it is noted that a larger size document for example A1 or A2
is often a design drawing of the like that does not have gradation, that
is binary-data. Accordingly, in the case of a design document, the 4 bits
provided by 2.sup.4 values-data is unnecessary. The image data can be
converted to 1 bit that is binary-data. As a result, the amount of the
data are compressed to a data compression ratio of 1/4.
In the present example, the size of the document is A1, the data amount of
the document is A1*4 bits, the size of the memory 302 is A4, the capacity
of the memory is A4*4 bits, and the maximum size of the printer 105 means
is A3, the capacity of the printer is A3*4 bits, similar to the first
embodiment. When the magnification ratio (the first magnification ratio)
is
(the capacity of the memory)/[(the data amount of the document)*(data
compression ratio)]=(A4*4 bits)/[(A1*4 bits)* (1/4)]=1/2
the reduced data can be stored in the memory. But the printed output size
becomes:
(the data amount of the document)*(the magnification ratio)*(the data
compression ratio)=(A1*4 bits)*(1/2)*(1/4)=(A1*4 bits)*(1/8)=(A1*1/8)*(4
bits)=(A4)*(4 bits)=(A2)*(1 bit),
and the printed output size A2 exceeds the maximum size A3 of the printer
when the printed output is binary data (1 bit). As a result, the
magnification ratio (second magnification ratio) has to be:
(the maximum size of the printer)/(the size of the document)=A3/A1=1/4 as
shown in FIG. 7(b).
That is, the magnification ratio has to be the following. The maximum size
of the printer is compared to
(the size of the document)*(the first magnification ratio) which equals
(the size of the document)*[(the maximum size of the printer)/{(the size of
the memory)*(data compression ratio)}]. This, in turn, equals
(the size of the memory)/(the data compression ratio),
(a) if (the maximum size of the printer)<[(the size of the memory)/(the
data compression ratio)],
the magnification ratio equals (the maximum size of the printer means)/(the
size of the document);
(b) if (the maximum size of the printer)>=[(the size of the memory)/(the
data compression ratio)],
the magnification ratio equals (the size of the memory)/[(the size of the
document)*(the data compression ratio)].
As a result, the size of the memory 302 and the maximum size of the printer
105 are used efficiently, particularly in case of (a), where the size of
the memory is smaller than the maximum size of the printer. The maximum
size of the printer can be printed without alteration.
FIG. 9 shows a detailed structure of a memory and a data controller used in
the second embodiment. The address block for the memory and data
controller of FIG. 9 is the same as that of the first embodiment shown in
FIG. 3.
The output data from the magnifier 103 are input to a binarization
processor 801 or 4-to-1 converter and the output data from the 2 values
processor 801 are input to input terminals(A) of buffers 805a, 805b, 805c,
805d. Also the output data from the magnifier 103 are input to input
terminals(A) of buffers 804a, 804b, 804c, 804d. The binarization process
select signal BIN from the operation panel 107 is input to output control
terminals(G) of the buffer 804a, 804b, 804c, 804d and a decoder 802. The
memory plane indicating signal NUM from the controller 106 is input the
input terminals(A,B) of the decoder and the output signals from output
terminals (Y0,Y1,Y2,Y3) of the decoder 802 are input to the output control
terminals(G) of the buffers 805a, 805b, 805c, 805d. The output signals
from the buffers 804a-d, 805a-d are input to the data terminals of the
memories 803a-d.
Next the operation of the second embodiment of the image holding device is
described. The data from the magnifier, for example 4 bit-data which are
2.sup.4 values-data D3, D2, D1, D0, are compressed to 1 bit-data which are
binary-data (0, 1) by 2 values processor 801. Then the amount of the data
is reduced. NUM signal in accordance with reading order of the document
that is upper right side, lower right side, upper left side and lower left
side is input to a decoder 802, that sets buffers 805a, 805b, 805c and
805d to an enabled condition in order. As a result, binary-data are stored
in each memory 803a, 803b, 803c and 803d. Now the on/off operation of the
binarization processor 801 is controlled by the signal BIN from the
operation panel 107, either 1 bit data not having gradation or 4 bits data
having gradation is selected. The operation thereafter is the same as that
of the first embodiment.
Thus, according to the above, for the second embodiment, the larger size of
the document, for example A1 size, can be combined and printed by the
magnification means 103 and the image holding device 104 even though the
scanner size, for example A3, is smaller than the size of the large
document. Moreover as it is noted that a large size document for example
A1 or A2 is often a design drawing or the like that does not have
gradation, the use of binary-data in this second embodiment, allows the
size of the memory and the maximum size of the printer to be used
efficiently, particularly when (the maximum size of the printer)<[(the
size of the memory)/(the data compression ratio)]. In this case, the
maximum size of the printer can be used even though the size of the memory
is smaller than the maximum size of the printer.
Modifications and variations of the above-described embodiments of the
present invention are possible, as appreciated by those skilled in the art
in light of the above teachings. It is therefore to be understood that,
within the scope of the appended claims and their equivalents, the
invention may be practiced otherwise than as specifically described.
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