Image reproduction apparatus capable of dividing an image into parts for reproduction on respective sheets

An image reproduction apparatus capable of dividing the image of a designated area into plural areas and reproducing thus divided image on plural recording sheets, thereby allowing one to obtain a large copy when these sheets are pasted together.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an image reproduction for producing an 
image on a recording material, such as a copying machine, a facsimile or 
the like. 
2. Related Background Art 
Conventional copying machine are often unable to reproduce the entire image 
of an original document in the enlarged copying mode due to the limitation 
imposed by the size of the recording sheet, which is usually A3 size at 
maximum. In order to obtain a copy of a size exceeding the maximum sheet 
size by pasting plural copy sheets together, the operator has to change 
the direction and position of the original document for each copying (the 
term "pasting is used throughout this specification and the claims, is a 
convenient generic term for suitable known methods of joining such sheets 
together). Also such pasting is cumbersome because the order of copies and 
the pasting margins thereof are not fixed. 
Therefore, there has already been proposed, in commonly-assigned the U.S. 
Pat. application Ser. No. 889,922, an apparatus capable of dividing an 
original image and recording the thus divided images respectively on 
different plural sheets after enlargement. Thus, the entire original image 
can be recorded in an enlarged size exceeding the size of the recording 
sheet, by pasting together the sheets on which divided images are 
respectively recorded. 
However, it is desirable that such process should be applicable not only to 
the entire original image but also to a desired partial area thereof. Also 
the pasting operation becomes tedious if the original image is divided 
into an excessively large number of areas. In addition the apparatus will 
be more convenient for use if the division and enlargement of the image is 
conducted according to the output image size desired by the operator. 
Furthermore the divided output images require margins for the pasting 
operation. 
SUMMARY OF THE INVENTION 
In consideration of the foregoing, an object of the present invention is to 
enable reproduction of an original image in a size larger than that of the 
available recording material. 
Another object of the present invention is to provide an image reproduction 
apparatus capable of dividing an arbitrary area of an original image and 
reproducing the thus divided images respectively on different recording 
materials. 
Still another object of the present invention is to provide an image 
reproduction apparatus capable of automatically determining the image 
magnification, optimum sheet size and number of divisions according to the 
output image size desired by the operator and reproducing the images of 
desired sizes on plural recording materials. 
Still another object of the present invention is to provide an image 
reproduction apparatus capable, in dividing an original image into plural 
areas and reproducing thus divided plural image areas respectively on 
different recording materials, of reproducing the original image in the 
center of an image frame constituted by plural recording materials. 
Still another object of the present invention is to provide an image 
reproduction apparatus capable, in dividing an original image into plural 
areas and reproducing thus divided plural image areas respectively on 
different recording materials, of dividing the original image in such a 
manner that neighboring image areas mutually overlap with an arbitrary 
amount of overlap. 
The foregoing objects and still other objects of the present invention, and 
the features and advantages thereof, will become fully apparent from the 
following detailed description of the preferred embodiments, taken in 
conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Now the present invention will be clarified by explanation of the preferred 
embodiments, shown in the attached drawings. 
FIG. 1--1 is an external view of a copying apparatus embodying the present 
invention and composed of a reader unit A for reading an original image 
and a printer unit B for reproducing the image on a recording material. 
The reader A is provided with an operation unit A-1. FIG. 1-2 is a 
cross-sectional view of the reader A and the printer B. The original 
document is placed, with its face down, on an original support glass 3, 
and is pressed thereon by an original cover 4. Said original is 
illuminated by a fluorescent lamp 2, and the light reflected from the 
original is focused on a CCD 1 through mirrors 5, 7 and a lens 6. 
The mirror 7 and the mirror 5 move with a relative speed ratio of 2 : 1. 
This optical system is reciprocated at a constant speed by a DC servo 
motor 28 under phase locked loop control. In the same-size copying mode, 
the forward motion from left to right is conducted at a speed of 180 
mm/sec, and the reverse motion from right to left is conducted at a speed 
of 800 mm/sec regardless of the image magnification. The maximum readable 
original size is A3, and the resolving power is 400 dots/inch. 
Consequently the CCD 1 is required to have: 
EQU 4678(=297/25.4.times.400) bits. 
Consequently the reader A employs a CCD of 5,000 bits. Also the period of 
main scanning is: 
EQU 352.7 .mu.sec (=10.sup.6 /180.times.25.4/400). 
The original image is linearly scanned by said CCD 1 to obtain an image 
signal representing the image density. 
Sensors 26, 27 are provided for detecting the position of the optical 
system. The sensor 26 detects that the optical system is at a home 
position, while the sensor 27 detects that the optical system has reached 
a front end position of the original support glass. 
The serial image signal obtained in the reader A is supplied to a laser 
scanning optical unit 25 of the printer B. Said unit 25 is composed of a 
semi-conductor laser, a collimating lens, a rotary polygon mirror, an 
F-.theta. lens and an image inclination correcting optical system. 
The image signal from the reader A is converted, in the semi-conductor 
laser, into a light beam, which is introduced through the collimating lens 
to the polygon mirror rotating at a high speed to scan a photosensitive 
member 8 through a mirror 24. Around said photosensitive member there are 
provided imaging process components, including a charge eliminator 9, a 
pre-exposure lamp 10, a primary charger 11, a secondary charger 12, a 
flush exposure lamp 13, and a developing unit 14. Also there are provided 
sheet cassettes 15, sheet feeding rollers 16, sheet guide members 17, 
registration rollers 18, a transfer charger 19, a separating roller 20, a 
conveyor guide 21, a fixing unit 22 and a tray 23 to transfer the image, 
formed on the photosensitive member 8, onto a recording sheet. The 
peripheral speed of the photo-sensitive member 8 and the speed of sheet 
transport are 180 mm/sec. Thus the printer B constitutes a so-called laser 
beam printer. At a lateral end of the photosensitive member 8 there is 
provided an unrepresented sensor for detecting the laser beam and 
generating a beam detection signal BD indicating the start of each 
scanning motion with the laser beam. 
The copying apparatus of the present embodiment has certain intelligent 
functions, including arbitrary variation of image magnification at a pitch 
of 1 % from 0.35 times to 4.0 times, image trimming for extracting a 
designated area of the image, image displacement for moving the thus 
extracted image to an arbitrary position on the sheet, and detection of 
the coordinates of the original image placed on the original support glass 
3, as will be further explained in the following. 
FIG. 2 is a detailed plan view of the operation unit A-1. 
There are provided a copy start key 100; a copy stop key 102; a reset key 
101 for resetting the copying mode to a standard state; numeral keys 103 
including a clear key C for clearing the entry with the numeral keys and 
an asterisk key * employed for entering numeral data such as those 
indicating a trimmed area; density up-down keys 108; a display unit 112 
for indicating the image density; a key 104 for turning on or off the 
detection of the coordinates of the original; a corresponding display 105; 
a copy number display unit 111; an error display unit 113; a key 109 for 
turning on or off the automatic density control function; a corresponding 
display unit 114; a key 110 for turning on or off a dither process 
function for a photograph original; a corresponding display unit 115; a 
key 116 for selecting the sheet cassettes and selecting an automatic sheet 
selecting function; a display unit 117 for displaying the selected sheet 
cassette; a display unit 118 for displaying the sheet size; a preset key 
display unit 122 for presetting the copying mode and recalling thus preset 
mode; a liquid crystal display unit 123 composed of 32 digits of 5.times.7 
display matrix; and software keys 124 for selecting one of the copy modes 
displayed on the display unit 123. 
There are further provided a display unit 125 for displaying the image 
magnification MY in the sub-scanning direction in %, a display unit 126 
for displaying the image magnification MX in the main scanning direction 
in %; a key 127 for alternately selecting the same size mode in which the 
image magnifications MX, MY respectively in the main and sub scanning 
directions are both 100 % and an automatic image size varying mode 
(MX=MY); keys 128, 129 for respectively increasing and decreasing MX and 
MY at the same time by 1 % at a time; keys 131, 132 for respectively 
increasing and decreasing MX only by 1% at a time; and keys 134, 135 for 
respectively increasing and decreasing MY only by 1 % at a time. 
FIG. 3 is a block diagram of the reader B. 
A CCD reader 301 is provided therein with a CCD, a clock driver therefor, 
an amplifier for the signal from the CCD, an A/D converter for converting 
said signal into a digital signal, etc. Thus the CCD reader 301 releases 
image data converted into digital signals of 6 bits (64 levels), which are 
supplied to a shading correction unit 302. 
After detection of shading in the light source and lens and correction 
therefor in the shading correction unit 302, the image data are 
temporarily stored in a shift memory unit 303, provided with shift 
memories of two lines, of which one is used for storing image data of N-th 
line while the other is used for releasing the image data of (N-1)-th 
line. The shift memory unit 303 is further provided with a write address 
counter for image data storage in the shift memories, a read address 
counter for reading image data from the shift memories, and an address 
selector circuit for selecting the address signals from said counters, as 
will be more detailedly shown in FIG. 5. 
A variable size/movement unit 304 varies the image size and moves the image 
in the main scanning direction by controlling the clock signals for image 
data writing or reading and the timing of image data reading, as will be 
more detailedly explained later. 
The image signals released from the shift memory unit 303 are supplied to a 
density processing unit 305 for binarizing process or dither process, and 
the obtained binary signals are supplied to a trimming process unit 306, 
which converts an arbitrary section of the image data of the main scanning 
line to "0" or "1", thereby enabling image editing, as will be later 
explained more detailedly. The binary signals from the density processing 
unit 305 are also supplied to an original position detecting unit 307, for 
detecting the position of the original on the original support glass 3 by 
means of said binary signals and detecting means to be explained later. 
A CPU unit 308 is composed of an already known microcomputer, provided with 
a CPU, a ROM, a RAM, a timer circuit and an I/0 interface. The CPU unit 
308 controls the reader A in response to the instructions from the 
operator through an operation unit 310 and also controls the printer B 
through serial communication. A motor driver 311 controls the speed of the 
DC servo motor according to the image magnification set by the CPU unit 
308. A lamp driver 312 turns on and off the fluorescent lamp 2 and also 
controls the intensity thereof. Sensors 313, 314, for sensing the position 
of the optical system, correspond to the sensors 26, 27 shown in FIG. 1-2. 
The reader A and the printer B are mutually connected through a connector 
JRl of the reader A and a connector JPl of the printer B, for exchanging 
control signals required for image data communication and for serial 
communication, as will be explained later in relation to FIGS. 10 and 11. 
From the printer B the horizontal synchronization signal BD synchronized 
with the image recording of each line is released through the connector 
JRl, and is supplied to a clock generator 309, which generates transfer 
clock signals for the CCD signals and read/write clock signals for the 
shift memories in synchronization with said synchronization signal BD. The 
printer B also supplies the reader A with a size signal, indicating the 
sheet size available on the printer, through the connectors JPl, JRl. 
FIG. 4 is a block diagram of the original position sensing unit 307 for 
detecting the coordinate of the original. 
A main scan counter 451, consisting of a down counter, indicates the 
scanning position in a main scanning line. Said counter 451 is set to the 
maximum value in the main scanning direction X in synchronization with the 
horizontal synchronization signal SHYNC for each line, and performs 
stepwise decrement for each image data clock signal CLK. A sub scanning 
counter 452, consisting of an up counter, is reset to "0" at the upshift 
of an image front end signal VSYNC, and performs stepwise increment in 
response to the signal HSYNC, thus representing the scanning position in 
the sub scanning direction. 
Prior to the original image reading, the CCD 1 performs a pre-scanning for 
detecting the coordinate of the original image, and the binary image data 
VIDEO obtained by said pre-scanning are supplied to a shift register 401 
in a unit of 8 bits. In response to the entry of 8 bits, a gate circuit 
402 identifies whether said 8 bits are all white "0", and, if so, releases 
a signal "1" to a signal line 403. In response to the appearance of first 
eight consecutive white bits after the start of original scanning, there 
is set a flip-flop 404 which is reset in advance by the signal VSYNC 
synchronized with the start of reading of an image frame and which remains 
set, after once being set, until the succeeding VSYNC signal. When said 
flip-flop 404 is set, a latch 405 latches the value of the main scanning 
counter 451 at this point, representing a coordinate Xl. Also a latch 406 
latches the value of the sub scanning counter 452 at this point, 
representing a coordinate Yl. In this manner a coordinate (Xl, Yl) is 
determined. 
Also at each supply of the signal "1" to the signal line 403, the value of 
the main scanning counter 451 is loaded in a latch 407. At the appearance 
of the first consecutive eight white bits, the value of the main scanning 
counter loaded in the latch 407 is compared, in a comparator 409, with the 
value of a latch 410 which is set at the maximum value in the X-direction 
in synchronization with the VSYNC signal. If the value of the latch 407 is 
smaller, said value is loaded in the latch 410. At the same time the value 
of the sub-scanning counter 452 is loaded in a latch 411. The 
above-explained procedure is completed prior to the entry of the 
succeeding eight bits into the shift register 401. In this manner the 
comparison of the values of the latches 407, 410 is conducted over the 
entire image area, whereupon the latch 410 retains the minimum value in 
the X-direction of the original image, while the latch 411 retains the 
corresponding coordinate in the Y-direction. Since the main scanning 
counter 451 is composed of a down counter, the coordinate corresponding to 
the minimum value in the X-direction represents a point (X3, Y3) farthest 
from the starting point of scanning. 
A flip-flop 412 is reset by the horizontal synchronization signal HSYNC, 
then set by the first consecutive white bits in the main scanning 
direction and remains set until the succeeding SHYNC signal. When said 
flip-flop 412 is set, the value of the main scanning counter corresponding 
to the position of the first white signal in a line is loaded in a latch 
413, and is compared, in a comparator 416, with the value of a latch 415 
which latches the minimum value "0" in the X-direction at the start of the 
VSYNC signal. If the value of the latch 415 is smaller than or equal to 
that of the latch 413, a signal 417 is activated to load the value of said 
latch 413 into the latch 415. The above-explained procedure is conducted 
between two neighboring signals HSYNC. The above-explained comparison is 
repeated over the entire image area whereupon the latch 415 retains the 
maximum coordinate of the original in the X-direction, i.e., the 
X-coordinate X2 of a white signal closest to the scanning start position 
in the main scanning direction. Also when the signal line 417 is 
activated, the value of the sub-scanning counter 452 is loaded in a latch 
418 as Y2. In this manner the coordinate (X2, Y2) is determined. 
At each appearance of consecutive eight white bits over the entire image 
area, the values of the main scanning counter 451 and of the sub scanning 
counter 452 are loaded respectively in latches 419, 420, in response to a 
signal 403. Consequently, at the end of the pre-scanning of the original 
image, the latches 419, 420 retain the counts (X4, Y4) at the appearance 
of last consecutive eight white bits. 
The data lines of the above-mentioned eight latches 405, 406, 415, 416, 
410, 411, 419, 420 are connected to a bus line BUS of the CPU 308 shown in 
FIG. 3, and the data of said latches are read by the CPU 308 at the end of 
the pre-scanning operation. 
In this manner there are obtained the coordinates Pl-P4 of four corners of 
the original document placed on the original support glass. From these 
coordinates there are determined the lengths DX, DY in the main scanning 
and sub scanning directions of the original document. 
FIG. 5 is a circuit diagram of the shift memory unit 303. Though the shift 
memory unit 303 has two shift memories as explained before, FIG. 5 shows 
only one shift memory since the control is same for both memories. There 
are provided a write address counter 904 for determining the address for 
data storage in a shift memory 907; a read address counter 905 for 
determining the address for data reading from the shift memory 907; an 
address selector 906 for selecting the address signal from the write 
address counter 904 or that from the read address counter 905 in response 
to a command from the CPU 308 received through an I/0 port 901; and I/0 
registers 902, 903 for supplying preset values from the CPU 308 to the 
write address counter 904 and the read address counter 905. 
Said write address counter 904 and said read address counter 905, both 
composed of down counters, respectively receive signals WST and RST for 
starting the counting operation, and also a write clock signal WCLK for 
data writing into the shift memory 907 and a read clock signal RCLK for 
data reading from the shift memory 907. 
A trimming process unit 306, corresponding to that shown in FIG. 3, is 
provided with exclusive 0R gates 915, 916, which are controlled by a 
signal OF. When said signal is "1", the inside of a frame defined by a 
start counter 912 and an end counter 913 while the outside of said frame 
is released as the output image, and vice versa in case said signal is 
"0". 
An AND gate 910 controls the output of image data released from the shift 
memory 907 and binarized in a density process unit 908. An AND gate 917 
released said masked area as black or white respectively when a control 
signal BB is "1" or "0". 
An OR gate 911 releases the image data from the gates 910, 917, as the 
VIDEO signal. An exclusive 0R gate 909 for controlling the inversion of 
the image data releases the original image data or inverted image data 
respectively when a control signal IN is "1" or "0". The above-mentioned 
signals are released by the CPU 308 according to the mode designated by 
the operator. 
In the start counter 912 and the end counter 913 for defining the image 
output area, count data for gating are preset by the CPU 308 through I/0 
port. 
A flip-flop 914 is set in response to the completion of counting operation 
of the start counter 912 and is reset in response to the completion of 
counting operation of the end counter 913, as shown in FIG. 6. 
For example, in case the signal OF is "1", the signal Q of the flip-flop 
914 is shifted to "1" at the completion of the counting operation of the 
start counter 912 to shift the output of the gate to "0", whereby the gate 
910 does not release output signal until the completion of the counting 
operation of the end counter 913, thereby achieving a masking operation. 
Instead the gate 916 releases a signal "1" to release a signal "1" from 
the gate 917 if the signal BB is "1", whereby the gate 911 releases a 
signal "1" to provide a black mask. On the other hand, a white mask is 
obtained in case OF="1" and BB="0". On the other hand, in case OF="0", the 
gates 915, 916 respectively release signals "1" and "0" so that the 
outside of the trimming area becomes black or white respectively when 
BB="1" or "0". 
In the following there will be explained the principle of varying image 
size. 
The image size variation in the sub scanning direction is achieved by 
varying the scanning speed of the optical system. Based on the image 
magnification designated by the operator, the CPU 308 calculates the speed 
of the DC servo motor 28, then determines the frequency of phase locked 
loop control corresponding to said speed, and presets said frequency in 
the motor driver 311 shown in FIG. 3 prior to the scanning operation. 
Since the sheet transport speed in the printer B is always 180 mm/sec, a 
size enlargement to 2 times or a size reduction to 1/2 times is achieved 
by moving the optical system with a half speed 90 mm/sec or a doubled 
speed 360 mm/sec. 
FIG. 7 shows the principle of image size variation in the main scanning 
direction. 
The serial signal of a constant frequency released by the CCD 1 and 
subjected to A/D conversion is sampled at a clock rate corresponding to 
the image magnification. In the case of a same-size copying mode, the data 
are written into the shift memory 907 with a write clock WCLK of a rate 
same as that of the transfer clock signal CLK for signal transfer from the 
CCD as shown in FIG. 7A, and are read from the shift memory according to a 
read clock signal RCLK of a rate same as that of the output clock signal 
VLCK for signal transfer to the printer B as shown in FIG. 7B. 
As an example, in case of image size reduction to half, the write clock 
signal WCLK for signal writing into the shift memory has a frequency which 
is a half of that of the transfer clock signal CLK as shown in FIG. 7C, 
whereby the original data are sampled at every other bit, while the data 
reading is conducted with the reading clock signal RCLK of a rate equal to 
that of the output clock signal VCLK as shown in FIG. 7B. 
In case of image size enlargement of 2 times, the data writing into the 
shift memory 907 is conducted in the same manner as shown in FIG. 7A while 
the data reading from the shift memory 907 is conducted with the read 
clock signal RCLK of a clock rate equal to one half of that of the output 
clock signal VLCK as shown in FIG. 7D, whereby each of the original data 
is amplified to two bits, thereby achieving an image enlargement of two 
times. 
Now reference is made to FIGS. 8 and 9 for explaining the principle of 
image movement. 
In the sub-scanning direction, the image movement in the sub-scanning 
direction is achieved, as shown in FIG. 8, by controlling the timing of 
original scanning and the timing of supply of the VSYNC signal to the 
printer B, as shown in FIG. 8. 
In the image reading, if the VIDEO signal is released with the VSYNC signal 
when the optical system reaches a position 1 with respect to the original, 
there is obtained an unmoved output signal as shown by (1). On the other 
hand, if the VIDEO signal is released with the VSYNC signal when the 
optical system reaches a position 2, the image is moved to the rear side 
of the recording sheet. Also if the VIDEO signal is released with the 
VSYNC signal when the optical system reaches a position 3, the image is 
moved to the front side of the sheet. 
The image movement in the main scanning direction is achieved, as shown in 
FIG. 9, by a change in the down-count start address to be given to the 
write address counter 904 and the read address counter 905 through the I/0 
registers 902, 903 shown in FIG. 5. 
For example, by displacing the reading start address to RADRI with respect 
to the writing start address WADR into the shift memory 907, the image 
data X0 is moved to right with respect to the main output scanning width 
VIDEO ENABLE as shown in (1). Also by moving the reading start address to 
RADR2, the data X3 corresponding to the address 0 of the shift memory is 
moved to left with respect to the VIDEO ENABLE signal as shown in (2). The 
effective image area signal VIDEO ENABLE shown in FIG. 9 determines the 
trimming area in the main scanning direction, defined by the start counter 
912, end counter 913, flip-flop 14, gates 915, 916, 917, 910, 911 shown in 
FIG. 5 and is used for providing white signals except for a section 
between the addresses 0 and WADR in the shift memory 907 shown in FIG. 9. 
Now reference is made to FIGS. 10 and 11 for explaining the timing of the 
interface signals to be exchanged between the reader A and the printer B. 
The beam detection signal BD is a front end signal in each main scanning 
line and is used for synchronizing the rotation of the polygon mirror of 
the printer B with the scanning operation or the image data of the reader 
A when it is connected with the printer B. The image data VIDEO consist of 
4678 pulses of a duration of about 56 .mu.sec each in each scanning line, 
and are synchronized with the beam detection signal BD when connected to 
the printer B, or with an internal pseud horizontal synchronization signal 
(hereinafter called HSYNC) in case of transmission to another unit. The 
section signal VIDEO ENABLE corresponds to the duration of 4678 pulses of 
said image data, and is synchronized with the signal BD or HSYNC. 
A section signal VSYNC indicates the image area in the sub-scanning 
direction. 
A signal PRINT REQUEST indicates a sheet feeding enabled state in the 
printer B. In response to this signal, the reader A instructs sheet 
feeding by a PRINT signal, and then releases the image data VIDEO together 
with the VSYNC signal after a time Tl determined in consideration of the 
image magnification, trimming area and amount of image movement 
corresponding to the copying mode designated by the operator. 
Input signals OHP, VTOP are entered by the sensors 313, 314 indicating the 
optical system as shown in FIG. 3. Signals BACK, FORWARD are supplied from 
the CPU 308, shown in FIG. 3, to the motor driver 311 for respectively 
driving the motor in the backward or forward direction. 
FIG. 11 shows signals S.DATA, S.CLK, CBUSY and SBUSY for communication 
between the reader A and the printer B. The signals S.DATA and S.CLK are 
bi-directional serial data and clock signals of 8 bits. The signal CBUSY 
is released when the reader A releases the data and clock signals, and the 
signal SBUSY is released when the printer B releases the data and clock 
signals. 
FIG. 10 is a timing chart showing examples of serial communication, such as 
a copy start command or a copy stop command from the reader A to the 
printer B. 
In the following there will be explained a divided copying mode, while 
making reference to FIGS. 12 to 15. 
FIG. 12A shows an original or designated area OG defined by DX0, DXl, DY0 
and DYl. 
FIG. 12 B shows an example of image output with plural sheets, in case said 
area OG, multiplied by an image magnification selected in the operation 
unit, cannot be accommodated in the main scanning and/or sub-scanning 
direction of a sheet. 
In FIG. 12B, the hatched area indicates said designated area OG after image 
size variation. In FIG. 12B plural sheets are mutually overlapped by 
predetermined amounts, as more clearly shown in FIG. 13. 
In this mode, if the size DX.multidot.MX, DY.multidot.MY, obtained by 
multiplying the detected or designated image area DX, DY with the image 
magnification MX, MY, is larger than the sheet size PX, PY available on 
the printer B, the original image is automatically divided to reproduce 
the image on plural sheets (NX sheets in the main scanning direction and 
NY sheets in the sub-scanning direction, or NX.multidot.NY sheets in 
total), thereby providing copies including an output image of a size 
DX.multidot.MX, DY.multidot.MY as shown in FIG. 12B. The image output is 
conducted as shown in FIG. 12B if DX.multidot.MX&gt;PX and DY.multidot.MY&gt;PY, 
but one sheet is enough in the sub-scanning direction if DX.multidot.MX&gt;PX 
and DY.multidot.MY.ltoreq.PY as shown in FIG. 15A. 
On the other hand, if DX.multidot.MX.ltoreq.PX and DY.multidot.MY&gt;PY, one 
sheet is enough in the main scanning direction as shown in FIG. 15B. 
Also in a case where DX.multidot.MX.ltoreq.PX and DY.multidot.MY.ltoreq.PY, 
there is required only one sheet in each of the main and sub-scanning 
directions, or only one sheet in total, as shown in FIG. 15C. In any of 
these cases, the effective image is automatically centered on one or 
plural sheets in either scanning direction. 
Now reference is made to FIGS. 16A and 16B for explaining the procedure in 
a divided copying mode. 
If the warming up procedure is completed without abnormality after the 
start of power supply, the liquid crystal display unit 123 shown in FIG. 2 
displays a message as shown in (1), indicating that the copying operation 
is enabled. The actuation of a key SK6, corresponding to the message 
"MODE", provides a display (2) for setting the copying mode. 
In the display (2), a message "NON-EDITING--" indicates that an editing 
mode such as image trimming is not selected, and a message "CENTER--" 
indicates that a centering mode is selected. In this state the actuation 
of the key SK6 corresponding to "ETC" allows to select other copying 
modes. The actuation of the key SK4 or SK5 selects an image movement mode, 
and the actuation of the key SKl or SK2 provides a display (3) for 
selecting the editing modes. 
In the display (3), a message "NONE--" indicates that none of the editing 
modes is selected, messages with "? " indicate that these modes are 
selectable. The actuation of the key SK3, corresponding to the message 
"DIV? ", for selecting the divided copying mode provides a display (4). 
The display (4) is used for setting the overlapping width or pasting margin 
for pasting plural recording sheets for either or both of the main (X) and 
sub (Y) scanning directions. 
In the display (4), cursors are blinking corresponding to the directions X 
and Y, and a number in the unit of millimeters is entered by the numeral 
keys 103. 
For example, the entry of a number "10" followed by the actuation of the 
asterisk key "*" provides a display (5), indicating the pasting margins 
for the X- and Y-directions, with a message "OK". 
The actuation of the key SK5 corresponding to the message "OK" provides a 
display (6). Also if a different margin in the Y-direction is desired, the 
key SK4 is depressed to obtain a display (11). 
In the display (11) a cursor blinks corresponding to the margin for the 
Y-direction. For example the entry of a number "20" followed by the 
actuation of the asterisk key "*" provides a display (12), and the 
actuation of the key SK5 corresponding to the message "OK" provides the 
display (5). 
The display (6) is used for selecting whether the division should be made 
on the entire original or on a partial area thereof. In case of the 
former, the key SK3 corresponding to the message "WHOLE? " is depressed, 
whereby the display is changed to (9), indicating the selection of a 
divided mode for the entire original. On the other hand, if the division 
is desired for a partial area of the original image, the key SK5 
corresponding to the message "T? " in the display (6) is depressed, 
whereby the display is changed to (7), which is used for designating the 
area to be divided, in units of millimeters independently in the main 
scanning and sub-scanning directions. 
A number entered by the numeral keys 103 is displayed at the position of 
three blinking cursors, and the actuation of the asterisk key moves the 
three blinking cursors to right. After the entry of four coordinates there 
is for example obtained a display (8), which is changed to a display (10) 
by the actuation of the key SK5 corresponding to a message "OK". The 
display (10) indicates the selection of the divided copying mode for a 
partial area of the original. 
Now reference is made to FIGS. 17A and 17B for explaining the control 
sequence of the divided copying mode. 
At first, when the divided copying mode is selected in the display (3) 
shown in FIG. 16, there are conducted settings of the image magnifications 
MX, MY in the main scanning and sub-scanning directions (SP501), pasting 
margins LX, LY in the main scanning and sub-scanning directions (SP502), 
and a particular area GX0, GXl, GY0, GYl, if necessary (SP503) according 
to the instructions from the operation unit. Then, in response to the 
depression of the start key, if the original sensing function is selected 
by the key 104 and the display unit 105 shown in FIG. 2 (SP504), there is 
conducted a pre-scanning for detecting the original (SP505) for detecting 
the original positions P0 (DX0, DY0) and Pl (DXl, DYl) as shown in FIG. 
12A according to the aforementioned principle (SP506). If the original 
sensing function is not selected (SP504), DX0 and DY0 are set to "0" and 
DXl and DYl are respectively set to "297" and "420" in consideration of 
the maximum reading area of A3 size of 297.times.420 mm (SP507). Then, if 
an area is designated (SP508), the data (GX0, GY0) and (GXl, GYl) of the 
reading area are corrected according to the position of the original 
(SP509). Then there are calculated the original size DX, DY (SP510), and 
the output size RX, RY obtained by multiplying the original size with the 
selected image magnification (SP511). Then the sheet sizes PXu, PYu and 
PX.sub.L, PY.sub.L of the sheets contained in the upper and lower 
cassettes of the printer B are set (SP512). The above-mentioned data are 
used for calculating the sheet size PX, PY to be employed in a step SP513, 
required numbers of sheets NX, NY and widths BX, BY of margin to be formed 
around the output image when the sheets are pasted together, according to 
a process flow shown in FIG. 17B. 
At first the numbers NX.sub.U, NY.sub.U of required sheets of the upper 
cassette are determined independently for the main and sub-scanning 
directions (SP527), and the numbers NX.sub.L, NY.sub.L of the required 
sheets of the lower cassette are determined likewise (SP528). For example 
the number NX.sub.U of the sheets of the upper cassette required in the 
main scanning direction is determined from the conditions 
RX-LX=(PXU-LX).multidot.NX.sub.U CXU and 
0.ltoreq.CXU.ltoreq.PXU-LX.multidot.CX and CY indicates the widths of 
margin around the image, and suffixes X, Y respectively indicate main 
scanning and sub-scanning direction, and U and L respectively indicate 
upper and lower cassettes. The numbers NY.sub.U, NX.sub.L and NY.sub.L can 
be determined in a similar manner. 
Then the numbers NX.sub.U, NY.sub.U are compared with the numbers NX.sub.L, 
NY.sub.L and a cassette requiring a smaller total number of sheets is 
selected (SP529). 
If the total number of sheets is equal, sheets providing a smaller margin 
are selected (SP530). 
Thus there are set the sheet size PX, PY, required sheet numbers NX, NY and 
margins BX, BY corresponding to thus selected cassette (SP531, SP532). The 
margins BX, BY are illustrated in FIG. 13. 
Said margins BX, BY of the output image are projected back onto the 
original image prior to the image size variation to obtain margins WX, WY 
(SP514). 
As shown in FIG. 12A, an actual reading area EX0, EXl, EY0, EYl is 
determined by adding said margins WX, WY to the designated reading area 
(SP515). 
Then the trimmed output size TX, TY for a single reading operation is 
determined from the sheet size PX, PY and the image magnification MX, MY 
(SP516), and the overlapping widths SX,SY of the trimmed area is 
determined from the pasting margins LX, LY designated by the operator and 
the image magnification MX, MY (SP 517). 
The above-mentioned values TX, TY, SX and SY are illustrated in FIG. 14A. 
Then a counter for effecting the trimming operations in the order shown in 
FIG. 14B is secured in an area i, j on the RAM, and an initial value "0" 
is set therein (SP518). 
In the divided copying mode of the present embodiment, the operator is only 
required to select the image magnification and the pasting margin, and the 
size and number of sheets required for obtaining an output image of 
desired size are automatically determined, as explained before, by the CPU 
308. Then the number of sheets NX, NY are displayed prior to the start of 
image reading operation (SP519). Subsequently the counters i, j are 
respectively increased by one for effecting the trimming operation (SP520, 
SP521). 
In general, as shown in FIG. 14A, the coordinates KX.sub.i0, KX.sub.il, 
KY.sub.j0 and KY.sub.jl for determining an (im j)-th trimmed area (i-th in 
the main scanning direction and j-th in the sub-scanning direction) are 
given by KX.sub.i0 =EX.sub.0 +(i-1)(TX-SX), KX.sub.il =KX.sub.i0 TX, 
KY.sub.i0 =EY.sub.0 +(j-1)(TY-SY) and KY.sub.il =KY.sub.i0 +TY. These 
values are thus calculated and set in a RAM area (SP522). 
Then the image reading is conducted and the image of the necessary area is 
trimmed according to the above-calculated coordinates and copied with an 
image size variation MX, MY (step 523). 
Upon completion of the image reading, the display of the copy number is 
decreased by one to show NY.multidot.NY-NY(i-1)-j(SP533). FIG. 18 shows an 
example of change of the display of copy number, in case MX=2 and NY=3. 
Thus the operator can know the remaining number of copies. Then there is 
discriminated whether the trimming operations of NY times have been 
completed (SP524), and, if not completed, the content of the trimming 
counter j in the sub-scanning direction is increased by one (SP521) for 
continuing the trimming operation. On the other hand, if said trimming 
operations are completed, said counter j is cleared (SP525), and there is 
discriminated whether the trimming operations of NX times have been 
completed in the main scanning direction (SP526). If not completed, the 
trimming counter i in the main scanning direction is increased by one 
(SP520), and the trimming counter j in the sub-scanning direction, which 
has been cleared to zero, is also increased by one to continue the 
trimming operation. On the other hand, if said discrimination turns out 
complete, indicating the completion of the trimmings of NX.multidot.NY 
times in total and the output of NX.multidot.NY copies in total, the 
copying operation in the present mode is terminated. 
In this manner the image of the entire original placed on the support glass 
as shown in FIG. 12A or of the designated area OG is divided into 
NX.multidot.NY trimmed areas of a size TX, TY with an overlapping margin 
SX, SY as shown in FIG. 14A and are copied in the illustrated order, 
whereby NX.multidot.NY copies are automatically obtained. 
Also the obtained copies can be pasted together with overlapping widths 
MX.multidot.SX, MY.multidot.SY as shown in FIG. 13 to obtain an enlarged 
copy of sizes DX.multidot.MX and DY.multidot.MY in the main scanning and 
sub-scanning directions, with a designated pasting margin, which cannot be 
obtained on a single copy sheet. 
In the present embodiment with the maximum sheet of A3 size and the maximum 
image enlargement of 400 %, the maximum image output is of dimensions of 
1188 mm and 1680 mm in the main scanning and sub-scanning directions, 
corresponding to two A0-sized sheets. 
As explained in the foregoing, there is obtained an image reproduction 
apparatus capable of providing an image, larger than the maximum sheet 
size available on the printer B, automatically on plural sheets without 
particular trouble to the operator. 
In addition the pasting margin can be arbitrarily selected, and the area 
division can be applied to an arbitrary area. There are also achieved 
additional functions such as the image centering in the image area 
obtained on mutually pasted copy sheets. 
In the foregoing embodiment, a reproduced image larger than the single 
sheet is obtained according to the image magnification selected by the 
operator. 
However, the apparatus will be more convenient for use if the output image 
size can be entered instead of the image magnification, since the operator 
often does not know the image magnification but does know the size of the 
end image. 
In the following there will be explained an embodiment emphasizing the 
performance and operability of the automatic trimming mode for obtaining 
an image enlarged in excess of the available sheet size, and enabling 
automatic setting of the sheet size, image magnification and number of 
divisions, wherein the operator is only required to select the output size 
larger than A3. 
FIG. 19 illustrates the setting procedure of the automatic edit-trimming 
mode. 
The display unit 123 of the operation unit Al shown in FIG. 2 provides a 
display (1) if the copying operation is not in progress and if there are 
no errors in the apparatus, and the actuation of the key SK6 corresponding 
to the message "MODE" provides a display (2), in which a message 
"NON-EDITING--" indicates that the trimming mode is not selected and a 
message "CENTER--" indicates that the centering function is selected. 
In the display (2), the actuation of the SK6 corresponding to a message 
"ETC" displays other selected functions. On the other hand, the actuation 
of the key SK4 or SK5 allows to select other image moving functions, and 
the actuation of the key SKl or SK2 provides a display (3). 
The display (3) indicates that there can be selected a trimming mode 
represented by "FRAME", a masking mode represented by "MASKING" or a book 
mode represented by "BOOK", or such mode can be cancelled by "BACK", and a 
message "NONE--" indicates that none of these modes has been selected. The 
actuation of the key SKl provides a display (4) allowing the operator to 
select either an automatic trimming mode for automatic division of the 
original image or a manual mode in which the operator can arbitrarily 
designate the trimmed areas. 
In the display (4), the actuation of the key SK3 corresponding to the 
message "AUTO.multidot..ltoreq." selects the automatic trimming mode, 
whereby provided is a display (5). The displays (5) and (6) allow to 
select the size of copies obtained as the result of automatic division, 
wherein the display (5) show A-series sizes while the display (6) show 
B-series sizes. 
In the display (5), the actuation of the key SK5 corresponding the message 
"ETC" provides the display (6), in which the actuation of the key SK5 
corresponding to the message "ETC" provides the display (5). Also in the 
display (5) or (6), the actuation of the key SK6 corresponding the message 
"BACK" again provides the display (4). The sizes displayed in (5) or (6) 
are larger than the maximum sheet size A3 but does not exceed a size equal 
to the maximum original size A3 times the maximum image magnification of 
400 % or the doubled A0 size. 
The selection of the automatic trimming mode is completed by the actuation 
of a key corresponding to a desired size in the display (5) or (6). 
The display (7) shows a case in which the key SKl corresponding to the 
message "B0" is actuated in the display (6). 
FIG. 20 shows the control sequence of the CPU 308 in the automatic 
edit/trimming mode. At first there is conducted a pre-scanning operation 
for sensing the position and size of the original (SP601). According to 
the principle explained before, the coordinates P0, Pl of the original OG 
placed on the support glass 2 as shown in FIG. 21(A) are determined and 
set in the RAM data areas DX0, DXl, DY0, DYl. Also the original sizes 
DXl-DX0, DYl-DY0 in the X- and Y-directions, determined from said 
coordinates are respectively set in the RAM data areas DX, DY (SP602). 
Subsequently the lengths in the main scanning and sub scanning direction, 
selected according to the selection shown in FIG. 19 corresponding to the 
final image size selected by the operator are set in the RAM areas RX, RY 
(SP603). 
Then the image magnifications MX=RX/DX, MY=RY/DY in the main scanning and 
sub-scanning directions, are determined from the original size DX, DY and 
the output image size RX, XY (SP604). Then the smaller one of said MX and 
MY is selected as the common image magnification MX, MY in the main 
scanning and sub-scanning directions and is set in the RAM data area 
(SP605, SP606). Since the maximum possible image magnification is 400 %, 
MX and MY are selected as 400 % in case the result of calculations in the 
steps SP604, SP605 and SP606 exceeds 400 % (SP607). In such case there is 
displayed that the image enlargement with the desired magnification is not 
possible or that the enlargement is conducted at 400 %. 
The output image size RX, RY is calculated again from the thus determined 
image magnification and set on the RAM (SP608). 
Then steps SP609 to SP616 select the optimum sheet. 
At first the sheet size of the upper cassette is set in RAM data areas 
PX.sub.U, PY.sub.U and that of the lower cassette is set in RAM data areas 
PX.sub.L, PY.sub.L (SP609). Then a value NX satisfying conditions 
RX=NX.sub.U PXU-aX.sub.u and 0&lt;aXU&lt;PX.sub.U and a value NY.sub.U 
satisfying conditions RY=NY.sub.U .multidot.PY.sub.U -YU and 0&lt;aY.sub.U 
&lt;PY.sub.U are calculated and set in RAM data areas (SP610). This 
calculation indicates that the output size selected by the operator 
requires NX.sub.U sheets in the main scanning direction and NY.sub.U 
sheets in the sub-scanning direction, or NX.sub.U .multidot.NY.sub.U 
sheets in total, when the sheets of the upper cassette are employed. 
Also the number of required sheets NX.sub.L, NY.sub.L for the lower 
cassette are likewise determined and set in RAM data areas (SP611). 
Then NX.sub.U .multidot.NY.sub.U is compared with NX.sub.L 
.multidot.NY.sub.L, and a cassette requiring fewer sheets is selected 
(SP612, SP614, SP615, SP616). If the required number of sheets is equal, a 
comparison is made between aX.sub.U .multidot.aY.sub.U and aX.sub.L 
.multidot.aY.sub.L (SP613).multidot.aX.sub.i or aY.sub.i (i=U, L) 
indicates the sum of overlapping widths of plural sheets required for 
obtaining a desired output size, and the step SP613 selects a cassette 
requiring a smaller overlapping width. 
Then the size of the trimmed area is inversely calculated by TX=PX/MX and 
TY=PY/MY from the automatically selected sheet size PX, PY and the already 
calculated image magnification MX, MY and is set in RAM data areas TX, TY 
(SP617). Then a value SX=(DX-TX.multidot.NX)/(NX-1) is calculated from the 
values NX, NY determined in SP615 or SP616, in order to read the original 
size DX by repeating the reading operation NX times with a trimmed area 
size TX in the main scanning direction, and the neighboring trimmed areas 
are mutually overlapped by a length SX. Similarly a value 
SY=(DY-TY.multidot.NY)/(NY-1) is calculated for the sub-scanning 
direction, and said values SX, SY are set in RAM data areas (SP618). 
The above-mentioned values NX, NY, TX, TY, SX and SY are illustrated in 
FIG. 21B. Then, in order to effect the trimmings in the order shown in 
FIG. 21B, counters are secured in RAM areas i, j and an initial value Q is 
set therein (SP619). 
In this manner the operator is only required to set the final image size, 
and the number of sheets required for obtaining said size is automatically 
calculated by the CPU 308. The number of trimmings NX.multidot.NY thus 
determined is displayed on the copy number display unit 111 prior to the 
start of image reading operation (SP620). 
Then, for executing the trimming operation, the contents of the counters i. 
j are respectively increased by one (SP621, SP622). In general, as shown 
in FIG. 21(B), coordinates KX.sub.i0, KX.sub.il, KY.sub.j0, KY.sub.jl 
defining an (im j)-th trimmed area (i-th in the main scanning direction 
and j-th in the sub-scanning direction) are given by KX.sub.i0 =DX0 
+(i-1)(TX-SX), KX.sub.il =KX.sub.i0 TX, KY.sub.i0 =DY.sub.0 +(j-1)(TY-SY), 
and KY.sub.il =KY.sub.i0 +TY as will be apparent from FIG. 14A. These 
values are thus calculated and set in RAM areas (SP623). 
Then image reading is conducted, and a required area alone is trimmed by 
the shift memory unit 303, based on the above-mentioned trimming 
coordinates and is reproduced after image size variation with a 
magnification MX, MY (SP624). 
Upon completion of the image reading, the display of the copy number 
display unit 111 is decreased by one to display a number 
NX.multidot.NY-NY(i-1)-j (SP625). 
Then there is discriminated whether a total of NY trimming operations have 
been completed in the sub-scanning direction (SP626), and, if not 
completed, the content of the sub-scanning trimming counter j is increased 
by one (SP622) to continue the trimming operation. On the other hand, if 
the trimming operations have been completed, said counter j is cleared to 
zero (SP627), and there is discriminated whether NX trimming operations in 
the main scan direction have been completed (SP628). If not, the main 
scanning trimming counter i is increased by one (SP621), and the counter 
j, which is already cleared to zero, is increased by one to continue the 
trimming operation. On the other hand, if said discrimination turns out 
complete, indicating the completion of NX.multidot.NY trimming operations 
and formation of NX.multidot.NY copies, the copying operation in the 
present mode is terminated. 
In this manner the original OG placed on the support glass 2 as shown in 
FIG. 21A is automatically divided into NX.multidot.NY areas of a size TX, 
TY each with an overlapping width SX, SY in the order illustrated in FIG. 
21B to obtain NX.multidot.NY copies in total. 
Also, the obtained copies can be pasted together with overlapping widths 
MX.multidot.SX, MY.multidot.SY as shown in FIG. 22 to obtain an enlarged 
copy of sizes RX=DX.multidot.MX and RY=DY.multidot.MY in the main scanning 
and sub-scanning directions, which cannot be obtained on a single copy 
sheet. 
In the present embodiment with the maximum sheet of A3 size and the maximum 
image enlargement of 400 %, the maximum image output is of dimensions of 
1188 mm and 1680 mm in the main scanning and sub-scanning directions, 
corresponding to two A0-sized sheets. 
In the foregoing explanation the maximum readable original size and the 
maximum recording sheet size are both selected as A3, but the present 
invention is not limited to such case and is applicable to originals and 
recording sheets of various sizes. 
Also, the detection of the original size need not be conducted by the image 
reading sensor but can be executed by an exclusive size detecting sensor. 
As detailedly explained in the foregoing, there is provided an image 
reproduction apparatus capable of automatically reproducing an image of a 
size exceeding the size of the available recording sheet, without any 
burden to the operator. 
The present invention is not limited to the foregoing preferred embodiments 
but is subject to various modifications and variations within the scope 
and spirit of the appended claims.