Image forming apparatus for forming a plurality of page images formed on one side of sheet on both sides of sheet

An image forming apparatus including an image forming unit for forming images of two pages on one side of a sheet and forming images of other two pages on the other side of the sheet, a storage unit for storing an image to be formed by the image forming unit, and a control unit for controlling to store images in the storage unit in a first mode of fastening or to fasten the longer side of the sheet so as to locate an image of a (4N-1)-th page at the back side of an image of a (4N-3)-th page and locate an image of a 4N-th page at the back side of an image of a (4N-2)-th page, and in a second mode of fastening or to fasten the shorter side of the sheet so as to locate an image of a 4N-th page at the back side of an image of a (4N-3)-th page and locate an image of a (4N-1)-th page at the back side of an image of a (4N-2)-th page, wherein the image forming unit forms the images in the storage unit located by the control unit, on the sheet.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an image forming apparatus for forming a 
plurality of page images formed on one side of a sheet on both sides of a 
sheet. 
2. Related Background Art 
A conventional image forming apparatus has a 2-in-1 mode and a 4-in-1 mode 
and records images on the front and back sides of a recording sheet. The 
2-in-1 mode copies two originals on the same side of one sheet, and the 
4-in-1 mode copies four originals on the same side of one sheet. 
The layouts of images formed after originals are stacked in a stacker of an 
image forming apparatus are shown in FIGS. 21 and 22 which illustrate the 
directions of originals and sheet feed directions. 
FIG. 23 illustrates the definitions of an original direction and a sheet 
feed direction. The original direction indicates whether an original 
placed in a stacker at a correct direction as viewed by a user positioned 
in front of the image forming apparatus, is vertically long or 
horizontally long relative to the arrow direction shown in FIG. 23. The 
sheet feed direction indicates whether a long edge or short edge of a 
sheet is first fed. 
FIG. 21 shows the positional relationship between images recorded on the 
both sides of a sheet in the 2-in-1 mode, and FIG. 22 shows the positional 
relationship between images recorded on the both sides of a sheet in the 
4-in-1 mode. In FIGS. 21 and 22, the sheet in the "front" column shows the 
state when viewed down to a paper ejection tray 2. A bold line 3 shows a 
staple fastened with a stapler 4. Originals are stacked in the order of 1, 
2, 3, 4, 5, 6, 7, and 8 from the top to the bottom. If the numerals 1 to 8 
are in the correct direction as viewed from a user, it is assumed that 
each original is placed at the correct direction. 
However, both the sheets of originals copied in the 2-in-1 mode and the 
sheets of originals copied in the 4-in-1 mode are fastened by a single 
staple 3. Therefore, these sheets can be turned over either on the 
vertical side or on the horizontal side. Assuming that the contents of a 
sheet on the front side are at the correct direction, the user cannot know 
at once which side is used to turn over pages. The user is required to 
check the correct turnover direction through a try and error basis. 
In order to avoid this problem, the user adds another staple, resulting in 
a cumbersome work with possible errors. 
If the contents of an original are written vertically, the copied images 
are disposed from the left to the right as the originals in the original 
stacker 1 are copied sequentially downward. Therefore, a user feels 
something different from the original images. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an image forming 
apparatus which can solve the above problems. 
It is another object of the present invention to provide an image forming 
apparatus capable of smoothly reading a plurality of sheets recorded with 
original images like reading a book. 
In accordance with one aspect of the invention there is a provided an image 
forming apparatus with an image forming means for forming images of four 
pages on the front side of a sheet, images of (8N-7)-th, (8N-6)-th, 
(8N-5)-th, and (8N-4)-th pages being formed respectively upper left, upper 
right, lower left, and lower right of the sheet, and forming images of 
four other pages on the back side of the sheet; storage means for storing 
an image to be formed by said image forming means; and control means for 
controlling to store images in said storage means, in a first mode of 
fastening or to fasten the longer side of the sheet and in the case of a 
portrait image or in a second mode of fastening or to fasten the shorter 
side of the sheet and in the case of a landscape image, so as to locate 
images of (8N-2)-th, (8N-3)-th, 8N-th, and (8N-1)-th pages respectively at 
the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th 
pages, and in said first mode and in the case of a landscape image or in 
said second mode and in the case of a portrait image, so as to locate 
images of (8N-1)-th, 8N-th, (8N-3)-th, and (8N-2)-th pages respectively at 
the back sides of images of (8N-7)-th, (8N-6)-th, (8N-5)-th, and (8N-4)-th 
pages, wherein said image forming means forms the images in said storage 
means located by said control means, on the sheet. 
The other objects and advantages of the present invention will become 
apparent from the following detailed description when read in conjunction 
with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
An embodiment of an image forming apparatus of this invention will be 
described. FIG. 1 is a diagram showing the structure of the image forming 
apparatus of the embodiment. In FIG. 1, reference numeral 1 represents an 
original feeder. 
As originals are placed on an original stacker la in a correct direction as 
viewed from an operator standing in front of the image forming apparatus, 
they are sequentially transported one after another by an original feed 
roller pair 1b to an original support glass plate 2. 
As the original is transported, a lamp 3 is turned on, and a scanner unit 4 
moves to illuminate the original. Light reflected from the original passes 
via mirrors 5 and 6 through a lens 8 and is applied to an image sensor 
unit 9. 
An image inputted to the image sensor unit 9 is processed in response to a 
control signal from a CPU circuit unit 27 to be described later, and 
directly inputted to an exposure control unit 10. Alternatively, the image 
may be temporarily stored in an unrepresented image memory and read 
therefrom, and thereafter inputted to the exposure control unit 10. 
An image signal from the image sensor unit 9 is converted into an optical 
signal by the exposure control unit 10. Light modulated by the image 
signal is applied to a photosensitive member 11 to form a latent image 
which is developed by a developer 12. Synchronously with this development, 
a paper sheet is transported from a paper stacker 14 and the developed 
toner image is transferred to the sheet by a transfer unit 16. 
The transferred toner image is fixed to the sheet by a fixer unit 17. If a 
both-side copy mode is selected, the sheet is fed to transport rollers 85 
and 86 by a paper eject flapper 88. Immediately when the back end of the 
sheet passes through a turnover flapper 83, the turnover flapper 83 
switches to position A shown in FIG. 1. At the same time, the transport 
roller 86 rotates in the reverse direction and the sheet is placed in an 
intermediate tray 84 by the transport roller 87. 
In order to form an image on the back side of the sheet, it is again fed 
and the image is formed. Thereafter, the sheet is ejected out of a paper 
ejector 18 to the outside of the apparatus. If a single side copy mode is 
selected, the sheet is ejected immediately after it is fixed. The ejected 
sheet is placed on a stapler/sorter 82. After all images of the originals 
are formed, two staples are fastened with a stapler 82a at the positions 
on the paper ejector 18 side. 
FIG. 2 is a block diagram showing the electrical structure of the image 
forming apparatus. Referring to FIG. 2, an image reading unit 21 is 
constituted by an optical system for receiving light reflected from an 
original image, a CCD for converting the reflected light from the optical 
system into an analog signal, and an A/D converter for converting the 
analog signal outputted from CCD into a digital signal. The read original 
image is sent to an image processing unit 22. 
The image processing unit 22 is constituted by a shading correction 
circuit, a light color density converter circuit, and an image editor 
circuit for editing an image such as magnification change, position 
change, and ornamentation in response to an instruction from the operator. 
The image processing unit 22 corrects or edits the image supplied from the 
image reading unit 21. 
The corrected or edited image is supplied via an image data selector 23 to 
an image memory 25 or an image recording unit 24. 
The image data selector 23 is constituted by a selecting circuit and a 
synthesizing circuit. The selecting circuit selects one of three buses in 
response to an instruction from the CPU circuit unit 27, the buses 
including a bus for sending image data from the image processing unit 22 
to the image recording unit 24, a bus for sending image data from the 
image processing unit 22 to the image memory 25, and a bus for sending 
image data read from the image memory 25 to the image recording unit 24. 
The synthesizing circuit synthesizes the image data sent from the image 
processing unit 22 and the image data read from the image memory 25. 
The image recording unit 24 transfers an image to a recording sheet in 
accordance with an image data density signal supplied from the image data 
selector 23. 
The image memory 25 writes image data supplied from the image data selector 
23 in the image memory at a predetermined position, or reads image data 
and supplies it to the image data selector 23, in response to an 
instruction from the CPU circuit unit 27. The image memory 25 also 
performs an image rotation process or an image synthesizing process. 
The CPU circuit unit 27 controls the whole apparatus, the image position 
and direction, and the operation of the stapler/sorter 82. The CPU circuit 
unit 27 is constituted by: a ROM for storing a control program, an error 
processing program, and other data; a RAM used for working areas of 
various programs; and a control unit for various timers. 
An operation unit 26 has: a variety of keys for informing the image 
processing unit of the image edit contents and supplying to an image 
forming operation information such as the number of copies; a display unit 
for displaying manipulation contents; and other devices. 
FIG. 3 is a front view of the operation unit 26. On the console panel, a 
display unit 138 made of a liquid crystal display with a dot matrix and 
various keys are mounted. 
The liquid crystal display unit 138 displays the status of the apparatus, 
the number of copies, a magnification, a selected paper sheet, and various 
operation screens, and is operated by control keys 131 to 135 and other 
keys. A start key 103 is used for starting a copy operation, and a return 
key 102 is used for returning from a set mode to the standard mode. A key 
group 105 includes ten keys from 0 to 9 for inputting the number of 
copies, a zoom magnification, and the like, and a clear key for clearing 
an input. A density key 107 is used for increasing or decreasing a 
density, the set density being displayed on a display unit 141. 
A key 137 is a key for turning on and off an automatic density control 
function and includes its display unit. A key 106 is a key for selecting a 
paper feed stage and an automatic paper selection function, the selected 
contents being displayed on the liquid crystal display unit 138. 
Keys 108 and 110 are used for selecting an equal magnification and a formal 
reduction/magnification. A key 118 and its display unit 117 are used for 
setting an automatic variable magnification mode and displaying the set 
mode. The contents set by these keys are displayed on the liquid crystal 
display unit 138. 
A reduction layout key 120 is used for setting a copy mode in which a 
plurality of original images are synthesized and copied on a single sheet. 
The setting sequence thereof is displayed on the liquid crystal display 
unit 138. FIG. 4 is a diagram illustrating the sheet processing set 
contents displayed on the liquid crystal display unit 138. 
FIGS. 5A to 5G are diagrams illustrating a method of reading/writing image 
data from/to the image memory 25. As shown in FIG. 5A, the image memory 25 
has a storage capacity of 4663.times.3298 bits corresponding to an A4 
size. The storage capacity may be increased. First, the method of storing 
original image in the image memory will be described with reference to 
FIGS. 5B and 5C. 
FIG. 5B illustrates how an A4 original placed on the original support glass 
plate 2 is stored in the image memory 25. An original placed as at (B1) in 
FIG. 5B is sequentially read as indicated by arrows. For reading the first 
line, as illustrated at (B2) in FIG. 5B, an X-direction counter is set to 
an up-count and a Y-direction counter is set to an up-count. As the first 
line is read, the Y-direction counter counts up, and the image data is 
sequentially written starting from address (0, 0) toward address (0, 
4662). 
Next, as the second line is read, the X-direction counter counts up, and 
the image data is sequentially written from address (1, 0) to address (1, 
4662). By sequentially reading the image data, it is written in the above 
manner toward address (3297, 4662). 
FIG. 5C illustrates how image data on an A4 original placed horizontally on 
the original support glass plate 2 is written in the image memory. The 
original placed as at (C1) in FIG. 5C is sequentially read in the 
directions indicated by arrows. For reading the first line, as illustrated 
at (C2) in FIG. 5C, the X-direction counter is set to a down-count and the 
Y-direction counter is set to an up-count. As the first line is read, the 
Y-direction counter counts up, and the image data is sequentially written 
starting from address (3297, 0) toward address (0, 0). Next, as the second 
line is read, the Y-direction counter counts up, and the image data is 
sequentially written from address (3297, 1) to address (0, 1). By 
sequentially reading the image data, it is written in the above manner 
toward address (0, 4662). 
Next, the method of reading the image data written in the image memory by 
the method illustrated in FIGS. 5B and 5C will be described with reference 
to FIGS. 5D, 5E, 5F, and 5G. 
As shown in FIG. 5D, the first line of the stored image data is read 
starting from address (3297, 0) to address (0, 0) in the X-direction, by 
setting the X-direction counter to the down-count and the Y-direction 
counter to the up-count and by sequentially counting down the X-direction 
counter. Next, the Y-direction counter is counted up to read the second 
line from address (3279, 1) to address (0, 1). By sequentially reading the 
image data in the above manner, an image at (D2) shown in FIG. 5D can be 
printed out. 
As shown in FIG. 5E, the first line of the stored image data is read 
starting from address (0, 0) to address (0, 4662) in the Y-direction, by 
setting the X-direction counter to the up-count and the Y-direction 
counter to the up-count and by sequentially counting up the X-direction 
counter. Next, the X-direction counter is counted up to read the second 
line from address (1, 0) to address (1, 4662). By sequentially reading the 
image data in the above manner, an image at (E2) shown in FIG. 5E can be 
printed out. 
As shown in FIG. 5F, the image data is read starting from address (0, 4662) 
by setting the X-direction counter to the up-count and the Y-direction 
counter to the down-count, and the image at (F2) shown in FIG. 5F can be 
printed out. 
As shown in FIG. 5G, the image data is read starting from address (3297, 
4662) by setting the X-direction counter to the down-count and the 
Y-direction counter to the down-count, and the image at (G2) shown in FIG. 
5G can be printed out. 
Therefore, if the original image of the vertical A4 shown at (B1) written 
in the method of FIG. 5B is read by the method of FIG. 5D, the original 
image can be rotated by 90 degrees in the clockwise direction, and if it 
is read by the method of FIG. 5E, it can be read without rotating it. If 
the original image of the horizontal A4 shown at (C1) written in the 
method of FIG. 5C is read by the method of FIG. 5D, the original image can 
be read without rotating it, and if it is read by the method 5E, it can be 
rotated by 270 degrees in the clockwise direction. 
Similarly, for the vertical A4 original, the combination of the methods 5B 
and 5F can rotate the image by 270 degrees in the clockwise direction, and 
for the horizontal A4 original, the combination of the methods 5C and 5F 
can rotate the image by 180 degrees, and the combination of the methods SC 
and 5G can rotate the image by 90 degrees in the clockwise direction. Both 
the vertical and horizontal originals can be read by rotating them by 0, 
90, 180, or 270 degrees in the clockwise direction. 
FIGS. 6A to 6D are diagrams illustrating the process of setting a reduction 
layout mode. As the reduction layout key 120 is depressed, the liquid 
crystal display unit 138 displays an original size input screen shown in 
FIG. 6A. A desired original size is set by moving a cursor by the control 
keys 131 to 135. After the original size is set, the liquid crystal 
display unit 138 displays a screen shown in FIG. 6B for setting the type 
of a layout and the number of originals. After the number of originals is 
set, the liquid crystal display unit 138 displays a screen shown in FIG. 
6C for setting an output sheet. A desired output sheet is selected by the 
control keys 131 to 135. Lastly, the liquid crystal display unit 138 
displays a screen shown in FIG. 6D for setting the type of an original. 
The above setting is controlled by the CPU circuit unit 27 and stored in 
RAM of the CPU circuit unit 27. 
FIGS. 7A and 7B are flow charts illustrating the copy process routine in 
the reduction layout mode. First, the number N of originals is set (Step 
S701). If the number of originals is already known, the number is 
substituted for the original number N. If the automatic original number 
mode is set, the originals are counted by the original feed unit 1 during 
an idle feed, and the count is substituted for the original number N. 
Other data is initialized (Step S702). Other data include the number L of 
reduced layout images on one side of a sheet, the number Z of sides on 
which images are formed, a horizontal length Px and a vertical length Py 
of a sheet, a shorter side length Pshort and a longer side length Plong 
determined from Px and Py, and a vertical length Oy and a horizontal 
length Ox of an original. 
Variable magnifications Mx and My are set (Step S703). FIG. 8 is a flow 
chart illustrating the routine of setting a variable magnification. It is 
first checked whether the automatic variable magnification mode is set 
(Step S801). If not set, the variable magnifications in the vertical and 
horizontal directions set on the operation unit 26 are inputted as the 
variable magnifications Mx and My (Step S811) to complete this routine. 
If the automatic variable magnification mode is set, it is checked whether 
the reduction layout mode is a 2-layout (2-in-1) (Step S802). If not, it 
is checked whether the reduction layout mode is a 4-layout (4-in-1) (Step 
S806). 
If the reduction layout is a 2-layout, the vertical and horizontal lengths 
Ox and Oy of an original are compared (Step S803). If the horizontal 
length Ox is equal to or longer than the vertical length Oy, i.e., if the 
original is horizontally long, the magnification Mx in the horizontal 
direction and the magnification My in the vertical direction are 
calculated from the equations (1) (Step S805). 
EQU Mx=(100.times.Pshort)/Ox 
EQU My=(100.times.Plong)/(2.times.Oy) (1) 
If the vertical direction Oy of the original is longer at Step S803, i.e., 
if the original is vertically long, the magnification Mx in the horizontal 
direction and the magnification My in the vertical direction are 
calculated from the equations (2) (Step S804). 
EQU Mx=(100.times.Plong)/(2.times.Ox) 
EQU My=(100.times.Pshort)/Oy (2) 
After the magnification Mx in the horizontal direction and the 
magnification My in the vertical direction are calculated, the 
magnification Mx in the horizontal direction is compared with the 
magnification My in the vertical direction and the smaller magnification 
is selected (Step S810) to complete this routine. 
If the reduction layout is the 4-layout at Step S806, the vertical and 
horizontal lengths Ox and Oy of the original are compared (Step S807). If 
the horizontal length Ox is equal to or longer than the vertical length 
Oy, i.e., if the original is horizontally long, the magnification Mx in 
the horizontal direction and the magnification My in the vertical 
direction are calculated from the equations (3) (Step S809). 
EQU Mx=(100.times.Plong)/(2.times.Ox) 
EQU My=(100.times.Pshort)/(2.times.Oy) (3) 
If the vertical length Oy of the original is longer, i.e., the original is 
vertically long, the magnification Mx in the horizontal direction and the 
magnification My in the vertical direction are calculated from the 
equations (4) (Step S808). 
EQU Mx=(100.times.Pshort)/(2.times.Ox) 
EQU My=(100.times.Plong)/(2.times.Oy) (4) 
After the magnification Mx in the horizontal direction and the 
magnification My in the vertical direction are calculated, the 
magnification Mx in the horizontal direction is compared with the 
magnification My in the vertical direction and the smaller magnification 
is selected (Step S810) to complete this routine and return to Step S704. 
Step S704 determines in accordance with the number Z of sides set at Step 
S702 which one of Steps S704A and S704B is to be performed. 
At Step S704A, the original arranging position n' is determined from the 
equations (5) by using the number L of layouts and the number of originals 
N(% indicates division). 
EQU n=N%2L, n'=n%L (5) 
Similarly at Step S704B, the original arranging position n' is determined 
from the equation (6) by using the number L of layouts and the number of 
originals N. 
EQU n'=N%L (6) 
The number L of layouts is compared, and in the case of the 2-layout the 
flow advances to Step S801 (Step S705) whereas in the case of the 4-layout 
the flow advances to Step S901 (Step S706). 
FIGS. 9 and 10 are flow charts illustrating the copy process for the 
2-layout. First, the horizontal and vertical lengths Ox and Oy of the 
original are compared to check whether the original is horizontally long 
or vertically long (Step S802). The operation will be described first 
wherein a horizontally long original with the vertical writing is used and 
an automatically selected paper sheet is transported in the horizontal 
feeding. 
It is checked whether the sheet is an automatically selected sheet (Step 
S803). If the automatically selected sheet is used, a horizontal feeding 
sheet is selected for a horizontally long original, and a vertical feeding 
sheet is selected for a vertically long original. For the automatically 
selected sheet, a vertical feeding sheet may be used for the horizontally 
long original and a horizontal feeding sheet may be used for the 
vertically long original. If a sheet is already selected on the operation 
unit 26, this sheet is used. 
It is checked whether the original selected as in FIG. 6D is a horizontal 
writing or a vertical writing (Step S804). The selection of the type of an 
original as in FIG. 6D is not necessarily required, and the vertical or 
horizontal writing may be always selected. This is preferable from the 
simplicity of user operation, if the user uses only the vertical writing 
or horizontal writing. 
In accordance with the original arranging position n' calculated at Step 
S704A, the X- and Y-direction counters are counted up or down (Step S805). 
If n'=1 (Step S806), the image data is written by setting the write start 
position (Sx, Sy) to the upper right corner (0, 0) of the sheet (Step 
S807). As a result, the image data is processed so as to form the image 
with the positions and directions of "1" and "2" indicated by arrows a and 
b in FIG. 15. FIG. 15 shows the positions and directions of the recorded 
images. "1", "2", "3", "4" indicate the (4N-3)-th page, (4N-2)-th page, 
(4N-1)-th page, and 4N-th page, respectively, where N is a natural number. 
If n'=0 (Step S808), the image data is processed so as to form the image 
with the positions and directions of "2" and "4" indicated by arrows c and 
d in FIG. 15. PL shown in FIGS. 9 and 10 indicates the longer side length 
of a sheet. After this routine, the flow returns to Step S707. 
If Step S804 indicates the horizontal writing, similar processes are 
performed (Steps S805A, S806A). If n'=1 (Step S807A), the image data is 
processed so as to form the image with the positions and directions of "1" 
and "3" indicated by arrows e and f in FIG. 15. If n'=0 (Step S808A), the 
image data is processed so as to form the image with the positions and 
directions of "2" and "4" indicated by arrows g and h in FIG. 15. 
If the sheet is not an automatically selected sheet at Step S803, the 
feeding direction is determined from the settings by the operation unit 26 
(Step S809). If the operation unit 26 sets the vertical feeding, similar 
processes are performed (Steps S804A to S806B). If the direction is the 
vertical writing and n'=1 (Step S807B), the image data is processed so as 
to form the image with the positions and directions of "1" and "3" 
indicated by arrows i and j in FIG. 15. If n'=0 (Step S808B), the image 
data is processed so as to form the image with the positions and 
directions of "2" and "4" indicated by arrows k and 1 in FIG. 15. 
If the direction is the horizontal writing and n'=1 (Step S807C), the image 
data is processed so as to form the image with the positions and 
directions of "1" and "3" indicated by arrows m and n in FIG. 15. If n'=0 
(Step S808C), the image data is processed so as to form the image with the 
positions and directions of "2" and "4" indicated by arrows o and p in 
FIG. 15. 
Similar processes are performed also when the original is judged to be 
vertically long at Step S802. Specifically, if the original is vertically 
long with the vertical writing and vertical feeding and n'=1 (Step S807D), 
then the image data is processed so as to form the image with the 
positions and directions of "1" and "3" indicated by arrows q and r in 
FIG. 15. If n''0 (Step S808D), the image data is processed so as to form 
the image with the positions and directions of "2" and "4" indicated by 
arrows s and t in FIG. 15. 
If the original is the horizontal writing and n'=1 (Step S807E), the image 
data is processed so as to form the image with the positions and 
directions of "1" and "3" indicated by arrows u and v in FIG. 15. If n'=0 
(Step S808E), the image data is processed so as to form the image with the 
positions and directions of "2" and "4" indicated by arrows w and x in 
FIG. 15. 
If the sheet is not an automatically selected sheet at Step S803A, the 
feeding direction is determined from the settings by the operation unit 26 
(Step S809). If the operation unit 26 sets the vertical feeding, similar 
processes are performed (Steps S804C to S806F). If the direction is the 
vertical writing and n'=1 (Step S807F), the image data is processed so as 
to form the image with the positions and directions of "1" and "3" 
indicated by arrows y and z in FIG. 15. If n'=0 (Step S808F), the image 
data is processed so as to form the image with the positions and 
directions of "2" and "4" indicated by arrows a1 and b1 in FIG. 15. 
If the direction is the horizontal writing and n'=1 (Step S807G), the image 
data is processed so as to form the image with the positions and 
directions of "2" and "4" indicated by arrows c1 and d1 in FIG. 15. If 
n'=0 (Step S808G), the image data is processed so as to form the image 
with the positions and directions of "1" and "3" indicated by arrows e1 
and f1 in FIG. 15. 
With the above processing, if in the 2-in-1 mode and in the both side mode 
a sheet is horizontally fed, i.e., the longer side of the sheet is 
stapled, a both side copy is performed so as to copy "3" at the back side 
of "1" and copy "4" at the back side of "2". If a sheet is vertically fed, 
i.e., the shorter side of the sheet is stapled, a both side copy is 
performed so as to copy "4" at the back side of "1" and copy "3" at the 
back side of "2". The vertical and horizontal feeding and the longer and 
shorter side stapling are related to the physical constraints of the 
stapler/sorter 82, because the position at which the stapler/sorter 82 can 
staple is limited to the area near the sorter eject port. 
With the above structure, each original position is changed depending upon 
whether the side at which two staples are used for fastening is a longer 
side or shorter side of a sheet. However, if the setting contents entered 
by an operator from the operation unit indicate that the fastening margin 
is formed along the longer side, the both side copy may be performed so as 
to copy "3" at the back side of "1" and copy "4" at the back side of "12". 
If the setting contents indicate that the fastening margin is formed along 
the shorter side, the both side copy may be performed so as to copy "4" at 
the back side of "1" and copy "3" at the back side of "2". 
With the above structure, a copy operation has been described. Obviously, 
similar effects as above can be obtained also when an image formed by 
computers or the like is printed in the 2-in-1 mode and both side copy 
mode. 
In both the shorter and longer side stapling modes and in the 2-in-1 both 
side copy mode, a book which does not give unnatural feelings when pages 
are turned over, can be formed. 
FIGS. 11 to 14 are flow charts illustrating the copy process for the 
4-layout. Similar to the 2-layout, first, it is checked whether the 
original is horizontally long or vertically long (Step S902). It is 
checked whether the sheet is an automatically selected sheet (Step S903). 
If the automatically selected sheet is used, a horizontal feeding sheet is 
selected for a horizontally long original, and a vertical feeding sheet is 
selected for a vertically long original. Similar to the 2-layout, for the 
automatically selected sheet, a vertical feeding sheet may be used for the 
horizontally long original and a horizontal feeding sheet may be used for 
the vertically long original. If a sheet is already selected on the 
operation unit 26, this sheet is used. 
Next, similar to the 2-layout, it is checked whether the original is a 
horizontal writing or a vertical writing (Step S904). In accordance with 
the original arranging position n' calculated at Step S704A, the X- and 
Y-direction counters are counted up or down (Step S905). The image data is 
written by setting the write start position (Sx, Sy) to the upper right 
corner (0, 0) of the sheet. PS in FIGS. 11 to 14 indicates the shorter 
side length of a sheet. 
If the original is vertically written and long with the horizontal feeding, 
the image data is processed so as to form the images with the positions 
and directions of "1" and "5" at n'=1 indicated by arrows a and b in FIG. 
16, the images with the positions and directions of "2" and "6" at n'=2 
indicated by arrows c and d in FIG. 16, the images with the positions and 
directions of "3" and "7" at n'=3 indicated by arrows e and f in FIG. 16, 
and the images with the positions and directions of "4" and "8" at n'=0 
indicated by arrows g and h in FIG. 16. After this routine is completed, 
the flow returns to Step S707 (Steps S906 to S912). "1", "2", "3", "4", 
"5", "6", "7", and "8" indicate the (8N-7)-th page, (8N-6)-th page, 
(8N-5)-th page, (8N-4)-th page, (8N-3)-th page, (8N-2)-th page, (8N-1)-th 
page, and 8N-th page, respectively, where N is a natural number. 
For the horizontal writing, similar processes are performed (S905A). The 
image data is processed so as to form the images with the positions and 
directions of "1" and "5" at n'=1 indicated by arrows i and j in FIG. 16, 
the images with the positions and directions of "2" and "6" at n'=2 
indicated by arrows k and l in FIG. 16, the images with the positions and 
directions of "3" and "7" at n'=3 indicated by arrows m and n in FIG. 16, 
and the images with the positions and directions of "4" and "8" at n'=0 
indicated by arrows o and p in FIG. 16. After this routine is completed 
the flow returns to Step S707 (Steps S906A to S912A). 
If the sheet is not an automatically selected sheet at Step S903, the 
feeding direction is determined from the settings by the operation unit 26 
(Step S913). If the operation unit 26 sets the vertical feeding, similar 
processes are performed (Steps S904A to S905B). If the direction is the 
vertical writing, the image data is processed so as to form the images 
with the positions and directions of "1" and "5" at n'=1 indicated by 
arrows q and r in FIG. 16, the images with the positions and directions of 
"2" and "6" at n'=2 indicated by arrows s and t in FIG. 16, the images 
with the positions and directions of "3" and "7" at n'=3 indicated by 
arrows u and v in FIG. 16, and the images with the positions and 
directions of "4" and "8" at n'=0 indicated by arrows w and x in FIG. 16. 
After this routine is completed the flow returns to Step S707 (Steps S906B 
to S912B). 
If the direction is the horizontal writing, the image data is processed so 
as to form the images with the positions and directions of "1" and "5" at 
n'=1 indicated by arrows y and z in FIG. 16, the images with the positions 
and directions of "2" and "6" at n'=2 indicated by arrows a1 and b1 in 
FIG. 16, the images with the positions and directions of "3" and "7" at 
n'=3 indicated by arrows c1 and d1 in FIG. 16, and the images with the 
positions and directions of "4" and "8" at n'=0 indicated by arrows e1 and 
f1 in FIG. 16. After this routine is completed the flow returns to Step 
S707 (Steps S906C to S912C). 
Similar processes are performed also when the original is Judged to be 
vertically long at Step S902. Specifically, if the original is vertically 
long with the vertical writing and vertical feeding, the image data is 
processed so as to form the images with the positions and directions of 
"1" and "5" at n'=1 indicated by arrows g1 and h1 in FIG. 16, the images 
with the positions and directions of "2" and "6" at n'=2 indicated by 
arrows i1 and j1 in FIG. 16, the images with the positions and directions 
of "3" and "7" at n'=3 indicated by arrows k1 and l1 in FIG. 16, and the 
images with the positions and directions of "4" and "8" at n'=0 indicated 
by arrows m1 and n1 in FIG. 16. After this routine is completed the flow 
returns to Step S707 (Steps S906D to S912D). 
If the original is the horizontal writing, the image data is processed so 
as to form the images with the positions and directions of "1" and "5" at 
n'=1 indicated by arrows o1 and p1 in FIG. 16, the images with the 
positions and directions of "2" and "6" at n'=2 indicated by arrows q1 and 
r1 in FIG. 16, the images with the positions and directions of "3" and "7" 
at n'=3 indicated by arrows s1 and t1 in FIG. 16, and the images with the 
positions and directions of "4" and "8" at n'=0 indicated by arrows u1 and 
v1 in FIG. 16. After this routine is completed the flow returns to Step 
S707 (Steps S906E to S912E). 
If the sheet is not an automatically selected sheet at Step S903A, the 
feeding direction is determined from the settings by the operation unit 26 
(Step S913A). If the operation unit 26 sets the horizontal feeding, 
similar processes are performed (Steps S904C to S905F). If the direction 
is the vertical writing, the image data is processed so as to form the 
images with the positions and directions of "1" and "5" at n'=1 indicated 
by arrows w1 and x1 in FIG. 16, the images with the positions and 
directions of "2" and "6" at n'=2 indicated by arrows y1 and z1 in FIG. 
16, the images with the positions and directions of "3" and "7" at n'=3 
indicated by arrows a2 and b2 in FIG. 16, and the images with the 
positions and directions of "4" and "8" at n'=0 indicated by arrows c2 and 
d2 in FIG. 16. After this routine is completed the flow returns to Step 
S707 (Steps S906F to S912F). 
If the direction is the horizontal writing, the image data is processed so 
as to form the images with the positions and directions of "1" and "5" at 
n'=1 indicated by arrows e2 and f2 in FIG. 16, the images with the 
positions and directions of "2" and "6" at n'=2 indicated by arrows g2 and 
h2 in FIG. 16, the images with the positions and directions of "3" and "7" 
at n'=3 indicated by arrows i2 and j2 in FIG. 16, and the images with the 
positions and directions of "4" and "8" at n'=0 indicated by arrows k2 and 
12 in FIG. 16. After this routine is completed the flow returns to Step 
S707 (Steps S906G to S912G). 
The positions and directions of images are determined from the table shown 
in FIG. 16. Even if the program shown in FIGS. 17 to 19 is used, the 
sheets with combined images can be smoothly read by a user like reading a 
general book similar to the case shown in FIG. 16. A plurality of tables 
may be used for allowing a user to select and deal with broad needs of the 
user. In contrast, for a user who does not write an original vertically in 
both the 2-layout and 4-layout cases, the positions and directions of 
images in the vertical writing mode are not necessarily required. 
After the processes described above, the flow returns to the main routine. 
At Step S707, originals in the original automatic feeder unit 1 are 
sequentially fed one after another to the original support glass plate 2. 
The image of the original is read in accordance with the contents set by 
the operation unit, a variable magnification set at the previous process, 
a write start address of the image memory 25, and other necessary data 
(Step S708), and stored in the image memory 25. 
The original arranging positions n' and n and the number N of originals are 
decremented by 1 (Step S709). It is checked whether the original arranging 
position n' is 0 or not (Step S710). If not 0, the flow returns to Step 
S705 to repeat similar processes. 
If n'=0, image data stored in the image memory 25 is printed out at Steps 
S713A and S714A. For printing, the image data stored in the image memory 
25 is read with or without rotation such as shown in FIGS. 5D to 5G, 
exposed and developed to transfer and fix the image to the sheet. 
If it is Judged to be Z=2 at Step S711 and not to be n=0 at Step S712, the 
back side of the sheet is printed at Step S713B. The sheet with the 
printed image on the front side is reversed by the reverse flapper 83 and 
stacked on the intermediate tray 84. If it is judged at Step S711 that Z 
is not 2, then the sheet is ejected out with one side printed. 
It is judged whether prints equal to the number as designated by the 
operation unit 26 have been completed (Step S715). If not completed, the 
flow returns to Step S711 to repeat the print operation at Step S713 or 
S714. 
If the print operation has been completed, it is judged at Step S716 
whether the number N of originals is 0 or not. If not, the flow returns to 
Step S704 to repeat similar operations as above. 
Thereafter, if the stapler/sorter was selected at the process shown in FIG. 
4, the stapler 82a fastens two staples at the positions indicated at 82b 
in FIG. 20. FIG. 20 is a plan view of the image forming apparatus. 
With the above processing, in the 4-in-1 mode and in the both side mode 
wherein "1", "2", "3", and "4" are disposed upper left, upper right, lower 
left, and lower right, if the longer side of the sheet is to be stapled 
(i.e., if the sheet is horizontally fed) and the direction of the original 
is vertically long, a both side copy is performed so as to copy "6" at the 
back side of "1", to copy "5" at the back side of "2", to copy "8" at the 
back side of "3", and to copy "7" at the back side of "4". If the shorter 
side of the sheet is to be stapled (i.e., if the sheet is vertically fed) 
and the direction of the original is horizontally long, a both side copy 
similar to the above arrangement is performed. 
If the longer side of the sheet is to be stapled (i.e., if the sheet is 
horizontally fed) and the direction of the original is horizontally long, 
a both side copy is performed so as to copy "7" at the back side of "1", 
to copy "8" at the back side of "2", to copy "5" at the back side of "3", 
and to copy "6" at the back side of "4". If the shorter side of the sheet 
is to be stapled (i.e., if the sheet is vertically fed) and the direction 
of the original is vertically long, a both side copy similar to the above 
arrangement is performed. 
In the 4-in-1 mode and in the both side mode wherein "1", "2", "3", and "4" 
are disposed upper left, upper right, lower left, and lower right, if the 
longer side of the sheet is to be stapled (i.e., if the sheet is 
horizontally fed) and the direction of the original is vertically long, a 
both side copy is performed so as to copy at "7" at the back side of "1", 
to copy "8" at the back side of "2", to copy "5" at the back side of "3", 
and to copy "6" at the back side of "4". If the shorter side of the sheet 
is to be stapled (i.e., if the sheet is vertically fed) and the direction 
of the original is horizontally long, a both side copy similar to the 
above arrangement is performed. 
If the longer side of the sheet is to be stapled (i.e., if the sheet is 
horizontally fed) and the direction of the original is horizontally long, 
a both side copy is performed so as to copy at t6" at the back side of 
"1", to copy "5" at the back side of "2", to copy "8" at the back side of 
"3", and to copy "7" at the back side of "4". If the shorter side of the 
sheet is to be stapled (i.e., if the sheet is vertically fed) and the 
direction of the original is vertically long, a both side copy similar to 
the above arrangement is performed. 
The vertically long original is also called a portrait, and the 
horizontally long original is also called a landscape. The information on 
the portrait/landscape may be discriminated by the direction of setting 
the original or by an input by the operator from the operation unit. 
With the above structure, a copy operation has been described. Obviously, 
similar effects as above can be obtained also when an image formed by 
computers or the like is printed in the 4-in-1 mode and both side copy 
mode. 
In all the shorter and longer side stapling modes and portrait/landscape 
modes and in the 4-in-1 both side copy mode, a book which does not give 
unnatural feelings when pages are turned over, can be formed. 
As described so far, according to the image forming apparatus of this 
embodiment, two staples are fastened after the 2-in-1 or 4-in-1 both side 
copy in accordance with the directions and positions of original images to 
be disposed. Therefore, the stapled sheets can be smoothly read by a user 
like reading a general book, irrespective of whether the originals are 
vertically or horizontally written.