Image forming apparatus

An apparatus relates to the switching of the flow of image data so as to optimize the data flow in accordance with the connection state of the respective optional boards of a PM unit, a FAX unit, a PRT unit, and an HDD unit. The flow of image data can be switched to optimize the data flow depending on the connection state of various optional boards.

BACKGROUND OF THE INVENTION 
The present invention relates to an image forming apparatus such as a 
digital copying machine having extended functions such as memory copying, 
a facsimile, and a printer, in addition to normal copying. 
Conventionally, an image forming apparatus such as a digital copying 
machine has extended functions such as memory copying, a facsimile, and a 
printer, other than normal copying. 
In extending the function in this manner, a page memory board serving as an 
image page memory, a facsimile board capable of 
facsimile-transmission/reception, a printer board serving as a printer 
interface for receiving printing data from a personal computer, and an HDD 
board capable of magnetically storing a large amount of data are mounted 
as optional boards, as needed. In this manner, the function can be 
extended. 
In this image forming apparatus, however, the flow of image data remains 
unchanged upon connecting various optional boards, and the data flow is 
often not optimal. 
BRIEF SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an image forming 
apparatus in which the flow of image data can be switched in accordance 
with the connection state of various optional boards so as to optimize the 
data flow. 
To achieve the above object, the present invention provides an image 
forming apparatus having read means for reading an image, and image 
forming means for forming an image of image data read by the read means on 
an image formation medium, comprising: a first processing board which is 
mounted on the image forming apparatus, has a page memory, and has a first 
function of forming an image of image data from an external device on the 
image formation medium by using the image forming means, and outputting 
the image data read by the read means to the external device; and a second 
processing board which is mounted on the image forming apparatus, and has 
a second function of storing the image data read by the read means and 
storing image data in executing the first function, wherein a flow of the 
image data is switched between a case in which only the first processing 
board is mounted on the image forming apparatus, and a case in which both 
the first and second processing boards are mounted on the image forming 
apparatus, and when both the first and second processing boards are 
mounted on the image forming apparatus, part of the first function of the 
first processing board is switched to be processed by the second 
processing board. 
The present invention also provides an image forming apparatus having read 
means for reading an image, and image forming means for forming an image 
of image data read by the read means on an image information medium, 
comprising: a first processing board which is mounted on the image forming 
apparatus, has a first page memory, and has a first function of forming an 
image of image data from a first external device on the image formation 
medium by using the image forming means, and outputting the image data 
read by the read means to the first external device; a second processing 
board which is mounted on the image forming apparatus, has a second page 
memory, and has a second function of forming the image of the image data 
from a second external device on the image formation medium by using the 
image forming means; and a third processing board which is mounted on the 
image forming apparatus, and has a third function of storing the image 
data read by the read means, storing image data in executing the first 
function, and storing image data in executing the second function, 
wherein, when at least the third processing board and the first or second 
processing board are mounted on the image forming apparatus, the first or 
second function of the first or second processing board is executed using 
the third function of the third processing board without using the first 
or second page memory of the first or second processing board, and in 
executing the first or second function, whether the first or second 
function is used by another function is determined, degrees of urgency are 
compared, when the first or second function is determined to have high 
urgency, the function in use having low urgency is temporarily 
interrupted, after the function having high urgency is performed, 
operation of the function having low urgency is continued again. 
The present invention further provides an image forming apparatus having 
read means for reading an image, and image forming means for forming an 
image of image data read by the read means on an image formation medium, 
comprising: a first processing board which is mounted on the image forming 
apparatus, has a first page memory, and has a first function of forming an 
image of image data from a first external device on the image formation 
medium by using the image forming means, and outputting the image data 
read by the read means to the first external device; a second processing 
board which is mounted on the image forming apparatus, has a second page 
memory, and has a second function of forming the image of the image data 
from a second external device on the image formation medium by using the 
image forming means; a third processing board which is mounted on the 
image forming apparatus, and has a third function of storing the image 
data read by the read means, storing image data in executing the first 
function, and storing image data in executing the second function; and a 
fourth processing board which is mounted on the image forming apparatus, 
has a storage capacity larger than a storage capacity of the third 
processing board, and has a fourth function of storing the image data read 
by the read means, wherein, when at least one of the processing boards is 
mounted on the image forming apparatus, a flow of the image data is 
switched to be optimized. 
The present invention further provides an image forming apparatus having 
read means for reading an image, and image forming means for forming an 
image of image data read by the read means on an image formation medium, 
comprising: a first processing board which is mounted on the image forming 
apparatus, has a page memory, and has a first function of forming an image 
of image data from an external device on the image formation medium by 
using the image forming means, and outputting the image data read by the 
read means to the external device; and a second processing board which is 
mounted on the image forming apparatus, and has a second function of 
storing the image data read by the read means and storing image data in 
executing the first function, wherein a flow of the image data is switched 
between a case in which only the first processing board is mounted on the 
image forming apparatus, and a case in which both the first and second 
processing boards are mounted on the image forming apparatus, and when 
both the first and second processing boards are mounted on the image 
forming apparatus, part of the first function of the first processing 
board is switched to be processed by the second processing board, and part 
of the first function of the first processing board is replaced with 
another function. 
Additional object and advantages of the invention will be set forth in the 
description which follows, and in part will be obvious from the 
description, or may be learned by practice of the invention. The object 
and advantages of the invention may be realized and obtained by means of 
the instrumentalities and combinations particularly pointed out in the 
appended claims.

DETAILED DESCRIPTION OF THE INVENTION 
An embodiment of the present invention will be described below with 
reference to the several views of the accompanying drawing. 
More specifically, the following description is directed to an embodiment 
in which the present invention is applied to a multi-functional image 
forming apparatus having three, copying machine, facsimile, and printer 
functions. 
FIG. 1 is a sectional view showing the internal structure of a digital 
copying machine as an example of the image forming apparatus of the 
present invention. 
As shown in FIG. 1, the digital copying machine comprises a machine main 
body 10. The machine main body 10 incorporates a scanner unit 4 
functioning as a read means (to be described later), and a printer unit 6 
functioning as an image forming means. 
A transparent glass original table 12 on which a read target, i.e., an 
original D is placed is arranged on the upper surface of the machine main 
body 10. An automatic document feeder 7 (to be referred to as an ADF 
hereinafter) for automatically feeding the original onto the original 
table 12 is disposed on the upper surface of the machine main body 10. The 
ADF 7 can be opened/closed with respect to the original table 12, and also 
functions as an original press for tightly pressing the original D placed 
on the original table 12 against the original table 12. 
The ADF 7 comprises an original tray 8 in which the original D is set, an 
empty sensor 9 for detecting the presence/absence of an original, a pickup 
roller 14 for picking up originals from the original tray 8 one by one, a 
paper feed roller 15 for conveying a picked original, an aligning roller 
pair 16 for aligning the leading end of the original, and a convey belt 18 
looped to cover almost the whole original table 12. A plurality of 
originals set in the original tray 8 with information-bearing surfaces 
facing up are sequentially picked up from the lowest page, i.e., the last 
page. The original is aligned by the aligning roller pair 16, and then 
conveyed by the convey belt 18 to a predetermined position on the original 
table 12. 
In the ADF 7, a reverse roller 20, a non-reverse sensor 21, a flapper 22, 
and a paper discharge roller 23 are disposed at an end portion opposite to 
the aligning roller pair 16 with respect to the convey belt 18. The 
original D from which image information is read by the scanner unit 4 (to 
be described later) is fed by the convey belt 18 from the original table 
12 to be discharged onto an original discharge portion 24 on the upper 
surface of the ADF 7 via the reverse roller 20, the flapper 22, and the 
paper discharge roller 23. When the lower surface of the original D is to 
be read, the flapper 22 is switched. The original D conveyed by the convey 
belt 18 is reversed by the reverse roller 20, and then fed again by the 
convey belt 18 to a predetermined position on the original table 12. 
The scanner unit 4 arranged in the machine main body 10 has an exposure 
lamp 25 serving as a light source for illuminating the original D placed 
on the original table 12, and a first mirror 26 for deflecting light 
reflected by the original D to a predetermined direction. The exposure 
lamp 25 and the first mirror 26 are attached to a first carriage 27 
arranged below the original table 12. 
The first carriage 27 is movable parallel to the original table 12, and is 
driven to reciprocate below the original table 12 by a driving motor via a 
toothed belt (neither are shown). 
A second carriage 28 movable parallel to the original table 12 is disposed 
below the original table 12. Second and third mirrors 30 and 31 for 
sequentially deflecting light reflected by the original D that has been 
deflected by the first mirror 26 are attached to the second carriage 28 at 
right angles to each other. The second carriage 28 is driven following the 
first carriage 27 by the toothed belt for driving the first carriage 27. 
The second carriage 28 is moved parallel to the original table 12 at a 
speed 1/2 that of the first carriage. 
An imaging lens 32 for focusing light reflected by the third mirror 31 on 
the second carriage 28, and a CCD sensor 34 for receiving and 
photoelectrically converting the reflected light focused by the imaging 
lens are disposed below the original table 12. The imaging lens 32 is 
movable via a driving mechanism within a plane including the optical axis 
of light deflected by the third mirror 31. The imaging lens 32 itself 
moves to image the reflected light at a desired magnification. The CCD 
sensor 34 photoelectrically converts the incident reflected light, and 
outputs an electrical signal corresponding to the read original D. 
The printer unit 6 comprises a laser exposure device 40 operating as a 
latent image forming means. The laser exposure device 40 comprises a 
semiconductor laser 41 serving as a light source, a polygon mirror 36 
serving as a scanning member for continuously deflecting a laser beam 
emitted by the semiconductor laser 41, a polygon motor 37 serving as a 
scanning motor for rotating the polygon mirror 36 at a predetermined 
rotational speed (to be described later), and an optical system 42 for 
deflecting the laser beam traveling from the polygon mirror to guide the 
laser beam to a photosensitive drum 44 (to be described below). The laser 
exposure device 40 having this arrangement is permanently supported by a 
support frame (not shown) of the machine main body 10. 
The semiconductor laser 41 is ON/OFF-controlled in accordance with the 
image information of the original D read by the scanner unit 4, 
facsimile-transmitted/received document information, or the like. A laser 
beam emitted by the semiconductor laser 41 is directed to the 
photosensitive drum 44 via the polygon mirror 36 and the optical system 42 
to scan the outer surface of the photosensitive drum 44, thereby forming 
an electrostatic latent image on the outer surface of the photosensitive 
drum 44. 
The printer unit 6 has the freely rotatable photosensitive drum 44 as an 
image carrier disposed at the center inside the machine main body 10. The 
outer surface of the photosensitive drum 44 is exposed by a laser beam 
coming from the laser exposure device 40 to form a desired electrostatic 
latent image. A charger 45 for charging the outer surface of the drum with 
predetermined charges, a developing unit 46 for supplying toner serving as 
a developing agent to the electrostatic latent image formed on the outer 
surface of the photosensitive drum 44 to develop the image at a desired 
image density, a transfer charger 48 which integrally has a separation 
charger 47 for separating, from the photosensitive drum 44, a transfer 
medium, i.e., a copying paper sheet P supplied from a paper cassette (to 
be described later), and transfers the toner image formed on the 
photosensitive drum 44 to the paper sheet P, a separation claw 49 for 
separating the copying paper sheet P from the outer surface of the 
photosensitive drum 44, a cleaner 50 for cleaning any toner left on the 
outer surface of the photosensitive drum 44, and a change remover 51 for 
charge-removing the outer surface of the photosensitive drum 44 are 
sequentially arranged around the photosensitive drum 44. 
An upper cassette 52, a middle cassette 53, and a lower cassette 54 each of 
which can be pulled out of the machine main body are stacked on each other 
at a lower portion in the machine main body 10. Copying paper sheets 
different in size are loaded in the respective cassettes. A large-capacity 
feeder 55 is arranged aside these cassettes. In the large-capacity feeder 
55, about 300 copying paper sheets P having a frequently used size, e.g., 
A4 size are stored. A paper feed cassette 57 also serving as a manual feed 
cassette 56 is detachably mounted above the large-capacity feeder 55. 
Inside the machine main body 10, a convey path 58 extending from each 
cassette and the large-capacity feeder 55 through a transfer portion 
located between the photosensitive drum 44 and the transfer charger 48 is 
formed. A fixing device 60 having a fixing lamp 60a is arranged at the 
terminal of the convey path 58. A discharge port 61 is formed in the side 
wall of the machine main body 10 facing the fixing device 60. A sorter 81 
is attached into the discharge port 61. 
A pickup roller 63 for picking up the paper sheets P from the cassette or 
the large-capacity feeder one by one is arranged near each of the upper 
cassette 52, the middle cassette 53, the lower cassette 54, the paper feed 
cassette 57, and the large-capacity feeder 55. Many paper feed roller 
pairs 64 for conveying, via the convey path 58, the copying paper sheet P 
picked up by the pickup roller 63 are arranged on the convey path 58. 
On the convey path 58, a registration roller pair 65 is disposed on the 
upstream side of the photosensitive drum 44. The registration roller pair 
65 corrects any skew of the picked copying paper sheet P. At the same 
time, the registration roller pair 65 aligns the leading end of a toner 
image on the photosensitive drum 44 and the leading end of the copying 
paper sheet P, and feeds the copying paper sheet P to the transfer portion 
at the same speed as the moving speed of the outer surface of the 
photosensitive drum 44. Before the registration roller pair 65, i.e., on 
the paper feed roller 64 side, a pre-aligning sensor 66 for detecting 
arrival of the copying paper sheet P is arranged. 
The copying paper sheets P picked up by the pickup roller 63 from each 
cassette or the large-capacity feeder 55 one by one are sent by the paper 
feed roller pair 64 to the registration roller pair 65. After the 
registration roller pair 65 aligns the leading end of the copying paper 
sheet P, the copying paper sheet P is fed to the transfer portion. 
At the transfer portion, a developing agent image, i.e., a toner image 
formed on the photosensitive drum 44 is transferred to the paper sheet P 
by the transfer charger 48. The copying paper sheet P having the toner 
image transferred thereon is separated from the outer surface of the 
photosensitive drum 44 by the operations of the separation charger 47 and 
the separation claw 49, and conveyed to the fixing device 60 via a convey 
belt 67 constituting part of the convey path 58. After the fixing device 
60 melts and fixes the developing agent image on the copying paper sheet 
P, the copying paper sheet P is discharged onto a sorter 81 via the 
discharge port 61 by a paper feed roller pair 68 and a paper discharge 
roller pair 69. 
An automatic both-side device 70 for reversing the copying paper sheet P 
having passed through the fixing device 60, and feeding the paper sheet P 
to the registration roller pair 65 again is arranged below the convey path 
58. The automatic both-side device 70 comprises a temporary stack 71 for 
temporarily stacking copying paper sheets P, a reverse path 72 branching 
from the convey path 58 to reverse the copying paper sheet P having passed 
through the fixing device 60 and guide it to the temporary stack 71, a 
pickup roller 73 for picking up the copying paper sheets P stacked in the 
temporary stack one by one, and a paper feed roller pair 75 for feeding 
each picked paper sheet to the registration roller pair 65 via a convey 
path 74. A selector gate 76 for selectively sending the copying paper 
sheet P to the discharge port 61 or the reverse path 72 is arranged at the 
branch portion between the convey path 58 and the reverse path 72. 
In both-side copying, the copying paper sheet P having passed through the 
fixing device 60 is guided to the reverse path 72 by the selector gate 76, 
and then temporarily stored in the temporary stack 71 while being 
reversed. The copying paper sheet P is sent to the registration roller 
pair 65 via the convey path 74 by the pickup roller 73 and the paper feed 
roller pair 75. After being aligned by the registration roller pair 65, 
the copying paper sheet P is sent to the transfer portion again. A toner 
image is transferred to the lower surface of the copying paper sheet P. 
Thereafter, the copying paper sheet P is discharged to the sorter 81 via 
the convey path 58, the fixing device 60, and the paper discharge roller 
pair 69. 
The sorter 81 is constituted by a convey roller 86 for conveying the paper 
sheet P discharged from the discharge port 61 of the main body 10, a gate 
means 84 for selectively sending the paper sheet P conveyed by the convey 
roller 86 to different destinations in accordance with sorting or 
non-sorting, a convey path 82 for conveying the paper sheet P sent by the 
gate means 84 in sorting, a plurality of bins 83a which face the outlet of 
the convey path 82 and are vertically movable by a bin moving mechanism 
(not shown), and a paper discharge tray 85 to which the paper sheet P sent 
by the gate means 84 in non-sorting is discharged. 
The convey path 82 is constituted by a convey guide 87a and a convey roller 
87b. 
A sensor 88 for detecting insertion of a paper sheet P from the discharge 
port 61 of the main body 10 to the sorter 81 is arranged near the convey 
roller 86. A sensor 89 for detecting conveyance of paper sheets P to the 
bins 83a is arranged near the convey roller 87b. 
An operation panel 90 allowing input of various copying conditions and a 
copying start signal for starting copying is disposed on the upper portion 
of the front surface of the machine main body 10. 
A control system for the digital copying machine will be described below 
with reference to FIGS. 2 to 5. 
The control system for the digital copying machine is roughly classified 
into two parts. 
The first part is a PPC engine unit made up of the ADF 7 for automatically 
feeding originals D to the original table 12 one by one, the scanner unit 
4 for optically scanning each original D and converting it into an 
electrical image signal corresponding to its image, an image processing 
unit 100 for receiving the electrical image signal from the scanner unit 4 
to perform adjustment of density characteristics, filtering, 
enlargement/reduction, gradation processing, and the like, the printer 
unit 6 for receiving an image signal from the image processing unit 100 to 
record an image on a copying paper sheet P, the sorter 81 for sorting the 
copying paper sheet P discharged from the printer unit 6, and an M 
(main)-CPU unit 101 for controlling the whole operation. 
The second part is constituted by the operation panel 90 serving as an 
interface with the user, a bus bridge unit 102 for converting an interface 
function with the M-CPU unit 101 or a local bus into a system bus, a PM 
unit (image page memory: PM board) 103 capable of holding image data 
corresponding to at least one page, a FAX unit (FAX board) 104 having a 
function capable of FAX-transmitting/receiving data to/from an external 
device 111 via a public line 110, a printer interface unit (PRT unit: PRT 
board) 105 for receiving printing data from a personal computer (PC) 112, 
an HDD unit (HDD board) 106 capable of magnetically storing a large amount 
of data, an SM (SysteM)-CPU unit 107 for controlling all the units, a ROM 
108 in which control programs used by the SM-CPU unit 107 are stored, and 
a RAM 109 for storing processing data. 
The PM unit 103, the FAX unit 104, the PRT unit 105, and the HDD unit 106 
are optional boards accessory to the fundamental arrangement of the 
copying machine. 
Expanded memories 103a, 104a,and 105a are respectively arranged in the PM 
unit 103, the FAX unit 104, and the PRT unit 105. 
The image processing unit 100 is connected to the PM unit 103, the FAX unit 
104, and the PRT unit 105 via image buses 113. The bus bridge unit 102, 
the operation panel 90, the PM unit 103, the FAX unit 104, the PRT unit 
105, and the HDD unit 106 are connected to each other via a system bus 
114. The bus bridge unit 102, the SM-CPU unit 107, the ROM 108, and the 
RAM 109 are connected to each other via a local bus 115. 
In the above arrangement, in response to an instruction from the user via 
the operation panel 90, the SM-CPU unit 107 of this machine instructs the 
M-CPU unit 101 to start operation such as copying. The M-CPU unit 101 
controls the ADF 7, the scanner unit 4, the printer unit 6, and the sorter 
81 to copy. At this time, the SM-CPU unit 107 sets processing parameters 
based on the processing scheme in the image processing unit 100. The image 
processing unit 100 performs image processing in accordance with sync 
signals from the scanner unit 4 and the printer unit 6. 
This machine realizes an extended copying function such as a memory copying 
function, a FAX function, and a printer function, in addition to a 
fundamental copying function. However, since all the users do not require 
a machine with all the functions, the functions other than the fundamental 
function can be added in accordance with demands of different users. That 
is, blocks surrounded by broken lines in each of FIGS. 2 to 5 are options. 
Each broken arrow indicates the flow of image data in accordance with the 
addition condition of options at that time. 
The flow of image data in the copying function will be explained with 
reference to FIG. 2. 
(a) is the flow of image data in the fundamental arrangement. At this time, 
the image data flows through the scanner unit 4, the image processing unit 
100, and the printer unit 6. (b) is the flow when the PM unit (image Page 
Memory) 103 is mounted as an option. 
In the latter case, data from the image processing unit 100 is temporarily 
held by the PM unit 103 via an image bus in units of pages, and compressed 
and stored as a compressed file. After all originals placed on the 
original table are stored as compressed files, the files are read and 
expanded from the first read file. The expanded file is sent as image data 
to the printer unit 6, which forms an image on a paper sheet P. This 
operation is repeatedly performed up to the last page to obtain copies 
sorted in the same order as that of the originals. In addition, by 
performing this operation repeatedly by a designated number of times, the 
designated number of copy sets can be obtained. 
In this way, a plurality of copy sets can be obtained though the scanner 
unit 4 reads image data only once. If the first copy set is actually 
stored as a compressed file, and data before compression is output to the 
printer unit 6, copy output can be prevented from delaying. 
The above file copying operation leads to a reduction in noise and energy 
saving owing to a smaller number of read operations, time saving because 
the user can quickly remove read originals, and the like. 
Image data flows through the same route in image synthesis in which a 
plurality of images are overlayed on each other, reduction synthesis 
editing in which a plurality of page images are reduced to be contained on 
one page, and the like. 
(c-1, c-2) are data flows when the file described in (b) is stored in not 
the PM unit 103 but the HDD unit 106 in order to increase the capacity. 
Since the file is stored in the HDD unit 106 at the sane time as the PM 
unit 103, the speed does not decrease. 
FIG. 3 shows the flow of image data in FAX transmission. 
(a) is the flow of image data when only the FAX unit 104 is added to the 
fundamental arrangement. Image data read by the scanner unit 4 and 
processed by the image processing unit 100 flows through an image bus to 
be received by the FAX unit 104. If necessary, the image is rotated 
because the image input direction for the copying machine is different 
from that for the FAX device. The image data is compressed in accordance 
with the ITU standard recommendation, and stored as a transmission file in 
the FAX unit 104. The FAX unit 104 transmits the transmission image data 
to a designated receiving FAX via a public line in the form of compressed 
data with the transmission time and source information. 
(b-1, b-2) are the flows of image data when the PM unit 103 is further 
added as an option to the arrangement in (a). When the PM unit 103 is 
added, image rotation or compression can be performed at a higher speed 
than in the case of adding only the FAX unit 104. For this reason, the 
image input operation can be performed at a higher speed for a plurality 
of originals, and reduction editing synthesis and the like can be 
performed. On the route at this time, image data from the image processing 
unit 100 is received by the PM unit 103, subjected to rotation/editing, as 
needed. The image data is compressed into a file, and then sent as a 
transmission file to the FAX unit 104. As far as the capacity of the page 
memory permits, the image data are transmitted in the input order when 
originals are manually input, or transmitted from the last page as one 
page when they are fed by the ADF 7. This is because the normal original 
input order of the copying machine is different from the original input 
order of the FAX device. This processing is not performed when the FAX 
unit 104 alone is added. Similar to the case of (a), the FAX unit 104 adds 
the transmission time and source information to the transmission file, and 
transmits the file to a receiving FAX via a public line. 
(c-1, c-2) are data flows when the file storage destination can be changed 
from the PM unit 103 and the FAX unit 104 to the HDD unit 106 to increase 
the file storage capacity, similar to the case of the copying function. 
With this setting, e.g., the number of transmission documents and the 
number of receiving end systems by time-designated FAX transmission can be 
increased. On the route in this case, image data output from the image 
processing unit 100 is temporarily received by the PM unit 103, subjected 
to rotation/editing, compressed into a file, and then temporarily stored 
in the HDD unit 106. After all originals stacked on the ADF are read by 
the scanner unit 4 and stored in the HDD unit 106, the image data is sent 
as transmission data to the FAX unit 104. The FAX unit 104 transmits the 
transmission file. 
FIG. 4 shows the flow of image data in FAX reception. When only the FAX 
unit 104 is connected to the fundamental arrangement indicated by solid 
lines, data flows as indicated by broken lines (a-1, a-2). That is, 
received FAX data is subjected to a compression code data check by the FAX 
unit 104, and then expanded to printing data. To print the printing data 
in accordance with copying paper sheets P present at the printer unit 6, 
the printing data is rotated, as needed, and output to an output image 
bus. The data is subjected to smoothing as output image processing and 
printed, and copies are discharged by the printer unit 6. 
When the PM unit 103 is further added to the arrangement of the fundamental 
arrangement+the FAX unit 104, the route changes to (b-1, b-2). In this 
arrangement, since the processing speed in units of pages increases, the 
time in simultaneously printing received documents can be shortened. FAX 
data received by the FAX unit 104 is subjected to a compression code data 
check by the FAX unit 104, then sent to the PM unit 103, and stored in 
units of pages. At this time, to allow the difference between the 
transmission data order of the FAX device and the normal printing order of 
the copying machine that has been described in the case of transmission, 
all pages by one communication are stored in the PM unit 103, and expanded 
and printed from the last page by the PM unit 103 so long as the capacity 
of the page memory permits. This processing is not performed when only the 
FAX unit 104 is added. 
When the HDD unit 106 is further added to the arrangement of the 
fundamental arrangement+the FAX unit 104+the PM unit 103, the route 
changes to (c-1, c-2). In this arrangement, the reception capacity greatly 
increases. Therefore, even if the apparatus operates as a copying machine 
or a FAX device, and is processing a job other than the communication 
currently being received, the communication is not disabled because of a 
sufficient reception capacity. Alternatively, the reception capacity of 
communication with a designated end system such as confidential 
communication in which a reception file cannot be erased unless the user 
at the receiver inputs a password and prints can be increased. 
On the route at this time, data received by the FAX unit 104 is subjected 
to a compression code data check by the FAX unit 104, and then stored in 
the HDD unit 106. When printing is designated, the data is read from the 
HDD unit 106 from the last page of the received document, and sent to the 
PM unit 103. After the data has undergone expansion processing/image 
rotation, the processed data is output to the image processing unit 100, 
smoothed, and printed by the printer unit 6. 
FIG. 5 shows the flow of image data upon receiving it by the printer unit 
6. This flow changes basically similarly to the case of FAX reception 
described with reference to FIG. 4. 
The minimum arrangement of the printer unit 6 is the fundamental 
arrangement+the PRT unit 105. At this time, while reception data are 
sequentially expanded by the PRT unit 105, and smoothed by the image 
processing unit 100 via an image bus, the data are printed by the printer 
unit 6. 
In an arrangement of the fundamental arrangement+the PRT unit 105+the PM 
unit 103, data corresponding to a plurality of pages can be stored in the 
PM unit 103 in units of documents, and printed by the printer unit 6 at 
once, or printed upon reduction/editing or the like. 
In an arrangement of the fundamental arrangement+the PRT unit 105+the PM 
unit 103+the HDD unit 106, even if the machine is used with another 
function such as the copying or FAX function, printer data can be 
received, and concurrent processing can be performed. 
FIGS. 6 to 9 show the internal arrangement of the PM unit 103, and the data 
flow in each operation. 
The interior of the PM unit 103 is divided into a system interface unit 
121, a memory controller unit 122, a CODEC (compressing/expanding) unit 
123, and an image interface unit 124. 
The system interface unit 121 is connected to the system bus of the SM-CPU 
unit 107 to mediate access of the SM-CPU unit 107 to an image memory, a 
setting resister, and the like. 
The memory controller unit 122 comprise rectangular address management 
units 131a to 131d for four channels, FIFO address control units 132a and 
132b for two channels, a system access control unit 133, and a DRAM 134 
linked to them. The memory controller unit 122 incorporates 
enlargement/reduction control units 135a and 135b for two channels, and 
rotation processing units 136a and 136b for two channels. A memory made up 
of the DRAM 134 is divided into a page buffer unit 137 and a code buffer 
unit 138, which is realized by dividing the memory area. In the memory 
controller unit 122, the respective channels operate independently 
parallel to each other. 
The CODEC unit 123 has a plurality of blocks for compressing or expanding 
data, and operate simultaneously parallel to each other. 
The image interface unit 124 has different data and sync signal lines for 
the printer unit 6 and the scanner unit 4 so as to allow an image input 
interface for the scanner unit 4 and a printer image output interface 
operate independently of each other. 
FIG. 6 shows the data flow in electronic sorting/copying in this 
arrangement. More specifically, data from the image processing unit 100 
which is obtained by reading an original image by the scanner unit 4 is 
stored in a memory area managed by the rectangular address management unit 
131a, i.e., the page buffer unit 137, as indicated by the broken line (a). 
Immediately after input of the data to the rectangular address management 
unit 131a starts, the contents are read by the rectangular address 
management unit 131b to start compression by the CODEC unit 123. In this 
case, the read address of the rectangular address management unit 131b 
does not exceed the write address of the rectangular address management 
unit 131a. 
The compressed data is stored in a memory area managed by the FIFO address 
management unit 132a, i.e., the code buffer unit 138. Upon completion of 
the data compression for one page, the image data of the first page in the 
page buffer unit 137 can be erased. Accordingly, input of the image of the 
second page can start. In practice, almost simultaneously as the read 
operation for the image on the first page is completed, the compression is 
completed because a read upon compression is performed at a sufficiently 
higher speed than in a page write. 
The read operation for the image on the second page upon switching 
originals starts immediately without having to wait for completion of 
compression for the first page. The operation indicated by routes (a), 
(b), and (c) is performed repeatedly by the number of originals to input 
the original data. 
To output an image to the printer unit 6 in outputting a copy, after the 
compressed data of the first page is stored in the code buffer unit 138, 
the compressed data of the first page is read out by the FIFO address 
management unit 132b. The data is sent to the CODEC unit 123 via a route 
(d), and expanded. 
The expanded data is stored via a route (e) in the page buffer unit 137 
managed by the rectangular address management unit 131c. After a 
predetermined time in accordance with an original size has elapsed upon 
the start of the expansion/storing operation via the route (e), the 
contents are read out by the rectangular address management unit 131b, 
start to be sent to the printer unit 6, and start to be printed on the 
paper sheet P. The predetermined time in accordance with the original size 
is set by subtracting the original transmission time to the printer unit 6 
from the longest time required for the expansion of the CODEC unit 123, in 
order to prevent the expansion speed from exceeding the printing speed. 
This time is determined by the paper size and the recording direction, and 
known in advance. 
The operation indicated by routes (d), (e), and (f) can be performed for 
the second and subsequent pages to output one set of copies. When a 
plurality of sets of copies are designated, this 
expansion/printing/transmission can be performed again from the first page 
repeatedly by the designated number of sets to output the plurality of 
sets of copies. 
FIG. 7 shows an operation from original input to a read of compressed data 
from the system assuming FAX transmission. 
In this case, the operation is basically the same as the image input 
operation in electronic sorting/copying described with reference to FIG. 
6. In the FAX, however, since data must be transmitted in a direction 
rotated through 90.degree. from the original read direction in normal 
copying, the read image must be rotated in compressing it. For this 
reason, upon completion of an image read operation for one page, the image 
data must be rotated and compressed. 
More specifically, after an image read/image input operation (a) for one 
page is completed, the image data is rotated by the rotation processing 
unit 136a, and sent to the CODEC unit 123 while being read by the 
rectangular address management unit 131b, as indicated by a route (b). The 
compressed data is stored via a route (c) in the code buffer unit managed 
by the FIFO address management unit 132a. Upon completion of this 
operation, the compressed data is read by the SM-CPU unit 107 via a route 
(d). 
FIG. 8 shows an operation from data download to output of printing image 
data to the printer unit 6 assuming FAX reception. 
In this case, the operation is basically the same as the image output 
operation in electronic sorting/copying described with reference to FIG. 
6. In the FAX, by rotating reception data through 90.degree., the data can 
be printed on a paper sheet (in a cassette) normally used in copying, 
similar to the case of FIG. 7. 
More specifically, the reception data stored in the code buffer unit via a 
route (a) is read out by using the FIFO address management unit 132a via a 
route (b), and sent to the CODEC unit 123. The data expanded by the CODEC 
unit 123 is mapped via a route (c) in the page buffer unit 137 managed by 
the rectangular address management unit 131d. The mapped data is read out 
by the rectangular address management unit 131c via a route (d), and 
processed by the rotation processing unit 136b. After that, the data is 
sent to the printer unit 6 via the image interface unit 124 to be printed. 
FIG. 9 shows the data flow assuming image rotation processing in FAX 
transmission. This operation exemplifies processing wherein, when the 
destination does not have any A3 reception ability in transmitting, e.g., 
an A3 image, the image is divided into images of two A4 pages, and the 
divided images are rotated and transmitted by the PM unit 103 capable of 
high-speed image editing to transmit the A3 image without any degradation, 
instead of normally reducing the A3 image to a B4 image, which degrades 
the image quality. 
That is, a FAX transmission file is downloaded from the SM-CPU unit 107 to 
the PM unit 103 via a route (a), expanded via a route (b), and mapped via 
a route (c) in the page buffer unit 137 managed by the rectangular address 
management unit 131d. A4 image data half the A3 image data is rotated as 
indicated by a route (d), while being sent to the CODEC unit 123 and 
compressed again. 
The re-compressed data is stored again via a route (e) in the code buffer 
unit 138 managed by the FIFO address management unit 132b. Then, the data 
is read out as transmission data by the SM-CPU unit 107, and transmitted 
by the FAX. The operation after a read via the route (d) is also performed 
for the other A4 image data to transmit the image data of two A4 pages, 
completing the operation. Since the complicated, time-consuming operation 
is processed by not a time-consuming dedicated option such as the FAX, but 
the PM unit 103 serving as a general-purpose option, the processing time 
can be shortened. 
The internal arrangement of the FAX unit 104 will be described below with 
reference to FIGS. 10 to 14. 
The FAX unit 104 controls the operation using a FAX-dedicated FAX-CPU 141 
for controlling the internal system, a ROM 142 in which the control 
programs of the FAX-CPU 141 are written, a work RAM 143, and the like. The 
FAX unit 104 is constituted by a system interface unit 144 as an interface 
with the SM-CPU unit 107 serving as a host CPU, an NV RAM unit 145 for 
storing information which must be held upon turning off the power supply, 
i.e., communication log information, the destination telephone number and 
name information, and the like, a code buffer RAM unit 146 for storing 
transmission/reception data in the form of compressed data, a page buffer 
RAM unit 147 for temporarily storing transmission/reception data in an 
image read operation or printing, a rotation editing unit 148 for 
performing rotation and the like of the data in the page buffer RAM unit 
147, a CODEC unit 149 for compressing/expanding image data, a MODEM unit 
150 for modulating transmission data in accordance with an analog line, 
and demodulating the modulated data to reception data, and an NCU unit 151 
for converting high-voltage signals of the MODEM unit 150 and a public 
line in two ways. 
In a normal case, a local bus 152 of the page buffer RAM unit 147 and the 
rotation editing unit 148 is connected to a system bus 153 of the FAX-CPU 
141. Only in rotation editing, the local bus 152 is disconnected from the 
system bus 153 to increase the efficiency of the rotation editing 
operation. 
That is, only in rotation editing, the local bus 152 is disconnected by a 
bus switch unit 154 while the rotation editing unit 148 itself accesses 
the page buffer RAM unit 147, and sends back the result of the rotation 
processing to the page buffer RAM unit 147 again. With this setting, the 
local bus 152 does not continuously disturb the system bus 153. At this 
time, the FAX-CPU 141 cannot access the page buffer RAM unit 147, but can 
operate free from any limitation. If the bus switch unit 154 is switched 
on, the FAX-CPU 141 can access the page buffer RAM unit 147 as a normal 
memory. 
The FAX-CPU 141 also incorporates a DMA function, and uses it in operation 
using the CODEC unit 149 such as compression, expansion, and code 
conversion, or operation using the system interface unit 144 such as 
exchange of transmission/reception data with the SM-CPU unit 107. The 
rotation editing unit 148 also incorporates a DMA function, and uses it in 
exchange of image data with the scanner unit 4 and the printer unit 6, 
rotation editing, or data transfer between an image interface unit 155 and 
the page buffer RAM unit 147 or the rotation editing function and the page 
buffer RAM unit 147. 
The code buffer RAM unit 146 and the page buffer RAM unit 147 incorporate a 
function of extending the memory capacity, thereby suppressing the cost of 
the fundamental arrangement low. For example, in this embodiment, the 
memory capacity of the page buffer RAM unit 147 in the fundamental 
arrangement is set to 1 MB as a capacity corresponding up to an A3 
original at low resolutions (8.times.3.85 and 8.times.7.7) in FAX 
transmission/reception, whereas the memory capacity of the code buffer RAM 
unit 146 is to 1 MB capable of storing, e.g., 100 compressed 
low-resolution originals. 
The page buffer RAM unit 147 and the code buffer RAM unit 146 can 
respectively be extended to +3 MB and +1 MB such that the memory capacity 
of the page buffer RAM unit 147 is extended to 4 MB corresponding up to an 
A3 original at a high resolution (16.times.15.4), and that of the code 
buffer RAM unit 146 is to 2 MB capable of storing 100 compressed 
high-resolution originals. 
An operation in original image scanning and FAX transmission in the above 
arrangement will be explained with reference to FIG. 10. This operation is 
equivalent to (a) in FIG. 3. 
An image read by the scanner unit 4 is input from the image interface unit 
155 to the page buffer RAM unit 147 via a route (a). If the image must be 
rotated, the image is rotated through 90.degree. by the rotation editing 
unit 148 via routes (b) and (c). The image data is sent to the CODEC unit 
149 via a route (d), and stored as a compressed file in the code buffer 
RAM unit 146 via a route (e). When the read operation of the original D 
starts, the FAX-CPU 141 controls and connects the NCU unit 151 to a line, 
and sends a signal indicating a destination number to connect the FAX to a 
receiving FAX. 
The FAX-CPU 141 determines the communication resolution, the transmission 
original size, the transmission speed, the transmission compression code 
type, and the like by negotiations to start transmitting the compressed 
data. Transmission data is the one stored in the code buffer RAM unit 146. 
To add transmission time information, source information, and the like as 
data to the transmission data, the data is temporarily expanded by the 
CODEC unit 149 every transmission. While adding an information image, the 
expanded data is compressed again with a compression code determined in 
negotiation with the destination. Meanwhile, the re-compressed data is 
stored in the code buffer RAM unit 146, transferred to the MODEM unit 150, 
and sent to the line. Routes (g) and (h) represent this. 
An operation in FAX reception using the FAX unit 104 and printing will be 
explained with reference to FIG. 11. This operation is equivalent to (a-1) 
and (a-2) in FIG. 4. 
The FAX-CPU 141 determines upon detection by the NCU unit 151 that a 
connection request is sent from a public line, and informs the SM-CPU unit 
107 of this. Upon reception of a connection grant from the SM-CPU unit 
107, the FAX-CPU 141 switches the NCU unit 151 to the line side, and sends 
a FAX response signal to the line side. If the sending system is a FAX, 
the FAX-CPU 141 determines the reception speed, the reception resolution, 
the reception image size, the reception compression code, and the like by 
negotiations, similar to transmission. The FAX-CPU 141 receives compressed 
data, and stores it in the code buffer RAM unit 146 via a route (a). 
To check the validity of the data, the received code is sent to the CODEC 
unit 149 to be subjected to expansion check (b). At the same time, the 
code is converted to one having the highest compression efficiency, and 
the converted code is restored in the code buffer RAM unit 146 (c). When 
the code corresponding to one page has been received, the code is expanded 
for printing (d). The expanded date is mapped in the page buffer RAM unit 
147 (e). 
If the data must be rotated, the printing data mapped in the page buffer 
RAM unit 147 is rotated by the rotation editing unit 148 in accordance 
with the direction of the paper sheet set at the printer unit 6 (f, g). 
The data of the page buffer RAM unit. 147 is sent to the printer unit 6 
via the image interface unit 155 (h) to be printed on the paper sheet P. 
An operation when, in scanning an original, an image is input via not the 
page buffer RAM unit 147 of the FAX but the PM unit 103 will be explained 
with reference to FIG. 12. This operation is equivalent to (b) and (c) in 
FIG. 3. 
Transmission data read and compressed by the PM unit 103 is downloaded to 
the code buffer RAM unit 146 in the FAX unit 104 via the system interface 
unit 144(a). Similar to the transmission operation in the arrangement with 
only the FAX unit 104, while transmission time information and source 
information are added, and the compression code is converted (b, c) upon 
completion of line connection and negotiation, the downloaded data is 
transmitted to a receiving FAX (d). 
In this operation, i.e., in the arrangement having the PM unit 103 as an 
option, no page buffer RAM unit 147 is used. For this reason, in the 
arrangement having the PM unit 103, the transmission/reception buffer 
capacity in the fundamental arrangement can be increased by using the page 
buffer RAM unit 147 as an extended portion of the code buffer RAM unit 
146. 
An operation when printing upon FAX-receiving data is performed via not the 
page buffer RAM unit 147 of the FAX unit 104 but the PM unit 103 will be 
explained with reference to FIG. 13. This operation is equivalent to 
(b-1), (b-2), (c-1), and (c-2) in FIG. 4. 
Similar to the reception operation in the arrangement with only the FAX 
unit 104, after line connection and negotiation, compressed data is 
received by the code buffer RAM unit 146 (a). During the reception, the 
received code data is subjected to code check/code conversion (b, c). Data 
determined to be free from any abnormality upon completion of the 
reception of data corresponding to one page is stored internally for a 
while or quickly sent in accordance with determination of the SM-CPU unit 
107. In any case, the data is finally uploaded to the SM-CPU unit 107 side 
(d). 
Also in this operation, since the page buffer RAM unit 147 is not used as a 
page buffer, similar to the case of FIG. 12, it is used as an extended 
portion of the code buffer RAM unit 146. 
DMA control in the FAX unit 104 will be described with reference to FIG. 
14. 
Generally, in transferring data at a high speed, DMA is performed, of 
resources managed by the FAX-CPU 141 by hardware, between memories, a 
memory and an IO, or IOs not using any transfer instruction of the FAX-CPU 
141. Accordingly, when data of a certain or larger amount is to be 
transferred, the data can be processed at a higher speed than in the case 
using the transfer instruction of the FAX-CPU 141. 
In this embodiment, the routes shown in FIGS. 10 to 13 are used for "(1) 
transfer of FAX transmission/reception data between the SM-CPU unit 107 
and the FAX unit 104", "(2) compression/expansion/code check/code 
conversion/source information adding operations using the CODEC unit 149", 
"(3) transfer of image data between the image interface unit 155 and the 
page buffer RAM unit 147 in inputting/outputting an image between the 
scanner unit 4, the printer unit 6, and the FAX unit 104", and "(4) 
transfer between the page buffer RAM unit 147 and the rotation editing 
unit 148 in rotating an image in the page buffer RAM unit 147". 
In "(1) transfer of FAX transmission/reception data between the SM-CPU unit 
107 and the FAX unit 104", the system interface unit 144 outputs a DMA 
request signal to the SM-CPU unit 107 and the FAX-CPU 141, and performs 
DMA transfer in accordance with DMA response signals from them. 
In transferring data from the SM-CPU unit 107 to the code buffer RAM unit 
146, the system interface unit 144 outputs a DMA request signal to the 
SM-CPU unit 107, and receives compressed data sent in accordance with a 
DMA response signal. The received data is latched by an intermediate 
buffer 144a inside the system interface unit 144. 
When the data is latched by the intermediate buffer 144a, the system 
interface unit 144 sets a signal (a) DREQ1 shown in FIG. 14 serving as a 
DMA request signal to true and outputs it to the FAX-CPU 141. The system 
interface unit 144 outputs, to a data bus, the data latched by the 
internal intermediate buffer 144a in correspondence with a signal (b) 
DACK1 serving as a response signal from the FAX-CPU 141. Then, the data is 
written in the code buffer RAM unit 146 in accordance with an address 
output from a DMA controller 141a in the FAX-CPU 141. 
When the internal intermediate buffer 144a becomes empty, the system 
interface unit 144 outputs a DMA request signal to the SM-CPU unit 107 
again, and tries to receive next data. By repeatedly performing the above 
operation, data is transferred from the SM-CPU unit 107 to the code buffer 
RAM unit 146. 
To the contrary, data is transferred from the code buffer RAM unit 146 to 
the SM-CPU unit 107 in the following order. The system interface unit 144 
changes the signal (a) DREQ1 to the FAX-CPU 141 to be true. The code 
buffer RAM unit 146 outputs reception data in accordance with an address 
output from the FAX-CPU 141 in response to the signal DREQ1. At the same 
time, the system interface unit latches the reception data in the internal 
intermediate buffer 144a in response to a signal (b) DACK1 output from the 
FAX-CPU 141. 
After the data is latched by the internal intermediate buffer 144a, the 
system interface unit 144 outputs a DMA request signal to the SM-CPU unit 
107, and outputs the data of the intermediate buffer 144a to the data bus 
on the SM-CPU unit 107 side in accordance with a DMA response signal from 
the SM-CPU unit 107. As a result, the SM-CPU unit 107 receives the 
reception data. 
When the SM-CPU unit 107 receives the data, it outputs a signal (a) DREQ1 
to the FAX-CPU 141 again in order to receive next data. By repeatedly 
performing this operation, e.g., FAX reception data is uploaded to the 
SM-CPU unit 107. 
In "(2) performing compression/expansion using the CODEC unit 149", the 
CODEC unit 149 outputs a DMA request signal (c) DREQ2 to the FAX-CPU 141. 
In response to this, the FAX-CPU 141 outputs a signal (d) DACK2 while 
outputting a RAM address. In accordance with this, the CODEC unit 149 
reads and writes data. The CODEC unit 149 always uses signals DREQ and 
DACK of two channels. 
More specifically, the CODEC unit 149 also simultaneously uses signals (e) 
DREQ3 and (f) DACK3. In data compression, the CODEC unit 149 uses a 
1st-channel DMA signal to read bitmap data of the page buffer RAM unit 
147. The CODEC unit 149 writes the result of the compression as a 
compressed file in the code buffer RAM unit 146 by using the 2nd-channel 
DMA signal. 
In data expansion, the data is transferred from the code buffer RAM unit 
146 to the page buffer RAM unit 147. 
In converting the code of compressed data or adding source information, the 
data is transferred from the page buffer RAM unit 147 to the code buffer 
RAM unit 146. 
In practice, as shown in FIGS. 10 and 11, the CODEC unit 149 of this 
embodiment has four pairs of DMA signals so as to simultaneously perform 
compression of read image and addition of source information/code 
conversion and FAX transmission, or FAX reception code check and code 
expansion/printing. For the sake of simplicity, the four pairs of DMA 
signals are not illustrated in FIGS. 10 and 11. 
An operation in "(3) inputting image data via the scanner unit 4 using the 
image interface unit 155, and outputting it to the printer unit 6" will be 
described. 
In inputting an image, when the image interface unit 155 receives image 
data by a bit width constituting the page buffer RAM unit 147, it outputs 
a DMA request signal (k) DREQL1 to the rotation editing unit 148. In 
response to this, the rotation editing unit 148 outputs a signal (i) BREQ1 
requesting bus access to the FAX-CPU 141. 
The FAX-CPU 141 stops its external bus operation as long as the operation 
does not have primal priority set internally, and outputs a signal (k) 
BGNT1 granting bus access to the rotation editing unit 148. Upon reception 
of this, the rotation editing unit 148 outputs a given address of the page 
buffer RAM unit 147, and outputs a response signal (l) DACKL1. Upon 
reception of the signal (l) DACKL1, the image interface unit 155 outputs 
the image data. The image data is written in the page buffer RAM unit 147. 
The above description is based on the assumption that the bus switch unit 
154 is switched on to connect the local bus 152 on the page buffer RAM 
unit 147 side to the system bus 153 on the FAX-CPU 141 side. If the bus 
switch unit 154 is switched off by an instruction from the FAX-CPU 141, 
the signal (i) BREQ1 from the rotation editing unit 148 is sent back as a 
signal (j) BGNT1. 
That is, when the local bus 152 is disconnected from the system bus 153 on 
the FAX-CPU 141 side, it can be freely used. In this state, image 
input/output, and image rotation (to be described later) can be performed 
independently of FAX transmission/reception. However, compressed data and 
bitmap image data cannot be converted. By controlling the 
connection/disconnection state of the bus switch unit 154, concurrent 
operation and multiple operation can be switched. 
In the ON state of the bus switch unit 154, a signal (g) BREQ1bf reflects 
the signal (i) BREQ1, whereas the signal (j) BGNT1 reflects the signal (h) 
BGNT1bf. In the OFF state, the signal (g) BREQ1bf always becomes "false", 
and as a result, the signal (h) BGNT1bf also always becomes "false". 
In outputting an image to the printer unit 6 using the image interface unit 
155, data flows in a reverse direction, but the sequence of flowing the 
DMA signal is the same as in inputting an image. 
"(4) Image rotation in the page buffer RAM unit 147" will be described. At 
this time, the rotation editing unit 148 itself has DMA request signals 
corresponding to two channels, and externally outputs the signal (i) BREQ1 
upon reception of them. The subsequent operation is the same as image 
input/output using the image interface unit 155. 
That is, an image received from the page buffer RAM unit 147 is input in 
the rotation editing unit 148 using the first channel. After rotating the 
image, the rotated image data is restored in another location in the page 
buffer RAM unit 147 using the second channel. 
By combining the above operations, compression/expansion processing of 
image data, FAX transmission/reception, and input/output of an image are 
performed parallel to each other in the FAX unit 104. 
The difference between control flows will be explained by exemplifying the 
FAX system. 
FAX task processing will be described with reference to a flow chart shown 
FIG. 15. 
For example, a control procedure for controlling FAX transmission/reception 
is transmitted to the FAX unit 104 when the power supply is first turned 
on after it is turned off, which may change the system configuration. 
More specifically, when the power supply is turned off (ST1), the FAX unit 
104 is reset (ST2) to get option information (ST3). 
From the option information, if the arrangement does not have any PM unit 
103 (ST4), the FAX unit 104 must perform both input of an original and 
printing of reception data, and both FAX transmission and reception 
processes by itself. The FAX unit 104 is instructed to operate 
independently (ST5). 
From the option information, if YES in ST4, no PM extended memory for 
storing a FAX transmission/reception file exists (ST7), and no HDD unit 
106 also exists (ST8), the FAX unit 104 is instructed to operate in a mode 
wherein storage of a transmission/reception file is performed within the 
FAX unit 104, and only input/output of an image is performed in the PM 
unit 103 (ST6 and ST9). 
If YES in ST4, and YES in ST7 or YES in ST8 even if NO in ST7, the FAX unit 
104 is instructed to operate in a mode wherein storage of a 
transmission/reception file is performed outside the FAX unit 104, and the 
FAX unit 104 performs only FAX transmission/reception (ST6, ST10, and 
ST11). 
The setting of the FAX operation mode does not change unless the power 
supply is turned off (ST1). 
If a new transmission request is generated (ST12), or during transmission 
processing (ST13), the transmission is continued (ST14). If a new 
reception request is generated (ST15), or during reception processing 
(ST16), the reception is continued (ST17). 
Transmission processing will be described with reference to flow charts 
shown in FIGS. 16 to 21. 
When the transmission mode is set upon depressing the start button (ST21), 
whether the setting items are correctly set is checked by UI processing 
(User Interface processing) (ST22). If NO in ST22, the control returns to 
the setting routine (ST23). 
If transmission suspension had occurred, and the control had branched once 
(ST24), the control jumps to the step where the suspension was generated, 
in order to execute processing therefrom. 
If time-designated transmission is set (ST25), another processing (ST26) 
must be performed, and the control shifts to another routine, description 
of which is omitted. 
At the start of transmission, if the ADF 7 cannot detect any original D 
(ST27), the control returns to a UI reprocessing -request for requesting 
the user to set the original D (ST28). 
If YES in ST27, the ADF 7 is instructed to feed the original D to the 
scanner unit 4 (ST29), and the result of original size detection obtained 
accordingly is received (ST30). 
The processing flow subsequent to the above processing changes depending on 
the form of the system configuration. 
As processing (A) subsequent to step 30, processing when no PM unit 103 
exists will be described with reference to a flow chart in FIG. 16. In 
this case, the FAX unit 104 performs all original input, file storage, and 
FAX transmission processing. 
A transmission start instruction with original input processing is output 
to the FAX unit 104 to check a response "OK" (ST31). If NO in ST31 because 
some processing such as FAX reception/printing is in progress in the FAX 
unit 104, the user is informed of this, and the control returns to 
abnormal end UI processing to temporarily end the processing (ST32). 
If YES in ST31, transmission condition information such as destination 
number information, transmission original size information, and density 
information is transferred. 
Although no abnormality generally occurs at this time, abnormality 
processing can be performed (ST33 and ST34). 
After transferring the transmission condition information, the scanner unit 
4 is instructed to start scanning the first original. If the processing 
normally ends upon reception of this instruction (ST35), the scanner unit 
4 outputs an image transfer sync signal. In accordance with the sync 
signal, the FAX unit 104 receives image data, and starts transmission upon 
compression processing. When the ADF 7 is instructed to feed an original, 
it feeds originals so long as originals D remain. Upon completion of the 
original feed, the ADF 7 replies "OK" (ST36). 
If an original or originals D are determined to remain, the FAX unit 104 is 
instructed to read the next original. Upon completion of preparation for 
reading the next original, the FAX unit 104 replies "OK" (ST37). If YES in 
ST37, the scanner unit 4 is instructed to start scanning the original, 
similar to the first original. In accordance with this, an original image 
is automatically transferred (ST35). This operation is repeatedly 
performed until no original D is present on the ADF 7 (ST35 to ST37). 
If NO in step 35, the control returns to abnormal end UI processing (ST38). 
If no original D is present on the ADF 7, the ADF 7 does not reply "OK" 
(normal end) for the original feed instruction (ST36). As a result, it is 
determined that no original D is present (ST39). 
If the ADF 7 does not reply "OK" owing to a reason other than the absence 
of an original D, an abnormality such as paper jam may have occurred 
(ST40). 
If YES in ST39, whether the last read original D is normally discharged 
from the ADF 7 is checked (ST41). After confirming that the original read 
processing to the FAX unit 104 has normally ended (ST42), the transmission 
processing ends. 
If NO in ST41, the control returns to abnormal end UI processing (ST43). If 
NO in ST42, the control returns to abnormal end UI processing (ST44). 
As processing (B) subsequent to step 30, processing when the PM unit 103 
exists, and neither a PM extended memory for the FAX unit 104 nor the HDD 
unit 106 exists, only original input is performed via the PM unit 103, and 
storage of a transmission file and FAX transmission processing are 
performed by the FAX unit 104 will be described with reference to a flow 
chart in FIG. 17. 
Substantially similar to the processing (A), it is inquired whether the FAX 
unit 104 can start transmission. If the FAX unit 104 replies "OK", the 
destination number, the transmission original size, and the transmission 
density are transmitted. Upon completion of the inquiry and instruction to 
the FAX unit 104, whether the PM unit 103 is in the process of copying or 
the like is checked. If the PM unit 103 is free, original input and 
compression are prepared for. The scanner unit 4 is instructed to scan an 
original, thereby receiving image data in the PM unit 103. 
Also at this time, the reception of data in the PM unit 103, and 
compression of the received data are automatically performed in response 
to an image transfer sync signal from the scanner unit 4. After checking 
whether the image compression has normally ended, the compressed file is 
transferred to the FAX unit 104 in units of pages. Upon completion of this 
operation, processing for the next and subsequent pages, i.e., feed of an 
original by the ADF 7, setting of the PM unit 103, scanner operation, 
check of compression, and transfer of a file to the FAX unit 104 are 
repeatedly performed until no original D is present on the ADF 7. If no 
original D is present, the original is discharged to end the transmission 
processing routine. 
More specifically, a transmission start instruction with original input 
processing is output to the FAX unit 104 to check a reply "OK" (ST51). If 
NO in ST51 because some processing such as FAX reception/printing is in 
progress in the FAX unit 104, the user is informed of this. To temporarily 
end the processing, the control returns to abnormal end UI processing 
(ST52). 
If YES in ST51, transmission condition information such as destination 
number information, transmission original size information, and density 
information is transferred. 
Although no abnormality generally occurs at this time, abnormality 
processing can be performed (ST53 and ST54). 
After transferring the transmission condition information, whether the PM 
unit 103 is in the process of copying or the like is checked (ST55). If 
the PM unit 103 is free, original input and compression are prepared for 
(ST56). 
The scanner unit 4 is instructed to start scanning the first original. If 
the processing normally ends upon reception of this instruction (ST57), 
the PM unit 103 receives image data from the scanner unit 4. 
Also at this time, the reception of data in the PM unit 103, and 
compression of the received data are automatically performed in response 
to an image transfer sync signal from the scanner unit 4. After checking 
whether the image compression has normally ended (ST59), the FAX unit 104 
is instructed to transfer the file. The compressed file is transferred to 
the PM unit 103, and whether the processing normally ends is checked 
(ST61). 
If NO in step 57 or 59, the control returns to abnormal end UI processing 
(ST58 or ST60). 
If YES in ST61, and the ADF 7 is instructed to feed an original, the ADF 7 
feeds originals as far as an original or originals D remain. Upon 
completion of the original feed, the ADF 7 replies "OK" (ST62). 
If an original D is determined to remain, the next original is input to the 
PM unit 103, and compression processing is prepared for (ST63). The 
scanner unit 4 is instructed to start scanning the original. If the 
processing normally ends (ST64), compression processing is performed in 
the PM unit 103. If the compression processing normally ends (ST65), the 
control returns to step 61. 
If NO in step 64 or 65, the control returns to abnormal end UI processing 
(ST66 or ST67). 
If no original D is present on the ADF 7, the ADF 7 does not reply "OK" 
(normal end) for the original feed instruction (ST62). As a result, it is 
determined that no original D is present (ST68). 
If the ADF 7 does not reply "OK" owing to a reason other than the absence 
of the original D, an abnormality such as paper jam may have occurred 
(ST70). 
If YES in ST68, whether the last read original D is normally discharged 
from the ADF 7 is checked (ST69) to end the transmission processing. 
If NO in ST69, the control returns to abnormal end UI processing (ST71). 
As processing (C) subsequent to step 30, processing when the PM unit 103 
and a PM extended memory for the FAX unit 104 exist, no HDD unit 106 
exists, original input processing and file storage are performed by the PM 
unit 103, and only FAX transmission is performed by the FAX unit 104 will 
be described with reference to flow charts in FIGS. 18 and 19. 
In this case, since the extended memory for storing a file exists on the PM 
unit 103, the image forming apparatus is controlled as a multi-functional 
copying machine to process input originals at once at a higher speed in 
order to complete FAX original input processing within a short time and 
quickly empty the image buffers of the ADF 7, the scanner unit 4, and the 
PM unit 103 for other operations. At the same time, as a supplementary 
function, to eliminate the principle disadvantage that the original feed 
order by the copying machine ADF 7 is from the last original page, pages 
are FAX-transmitted from the first page stacked on the ADF 7 after reading 
all the pages, i.e., the pages are sequentially sent to the FAX unit 104 
in the order from the last read page. 
In transferring a file to the FAX unit 104 after all the original pages are 
read at once, the files of the respective pages cannot be continuously 
transferred due to the influence of the line speed. Therefore, a 
transmission suspension flag is set until transmission of the next file 
starts upon transferring the file of one page, thereby generating a 
routine for temporarily branching from the task for the purpose of another 
processing. 
In a suspension state, the transmission processing routine is repeatedly 
performed until the FAX unit 104 can transfer the next file. When the 
files of all the pages have been transferred, the transmitted files in the 
extended memory are erased for next transmission. To perform padding for 
the memory upon the erase, filling (garbage collection) the space with a 
time-designated transmission file and the like is performed, and the 
control branches from this routine. 
More specifically, access to the PM unit 103 is requested, which is retried 
until the PM unit 103 replies "OK" (ST81). 
If access to the PM unit 103 is granted, an original is input to the PM 
unit 103, compression processing is prepared for, a FAX transmission file 
area is initialized, and the number of pages is initialized (ST82). 
The scanner unit 4 is instructed to start scanning an original. If the 
processing normally ends upon reception of this instruction (ST83), the PM 
unit 103 receives image data from the scanner unit 4. 
Also at this time, the reception of data in the PM unit 103, and 
compression of the received data are automatically performed in response 
to an image transfer sync signal from the scanner unit 4. After checking 
whether the image compression has normally ended (ST85), the number of 
input pages is counted up (ST87). 
If NO in step 83 or 85, the control returns to abnormal end UI processing 
(ST84 or ST86). 
Subsequent to step 87, the next original is input to the PM unit 103, 
compression processing is prepared for, and the next page of the FAX 
transmission file area is initialized (ST88). 
The ADF 7 is instructed to feed the next original. If the ADF 7 replies 
"OK" upon reception of this instruction (ST89), the scanner unit 4 is 
instructed to start scanning the next original. If the processing normally 
ends upon reception of this instruction (ST90), the PM unit 103 receives 
image data from the scanner unit 4. 
Also at this time, the reception of data in the PM unit 103, and 
compression of the received data are automatically performed in response 
to an image transfer sync signal from the scanner unit 4. After checking 
whether the image compression has normally ended (ST92), the number of 
input pages is counted up (ST94). 
If NO in step 90 or 92, the control returns to abnormal end UI processing 
(ST91 or ST93). 
If no original D is present on the ADF 7, the ADF 7 does not reply "OK" 
(normal end) for the original feed instruction (ST89). As a result, it is 
determined that no original D is present (ST95). 
If the ADF 7 does not reply "OK" owing to a reason other than the absence 
of the original D, an abnormality such as paper jam may have occurred 
(ST96). 
If YES in ST95, whether the last read original D is normally discharged 
from the ADF 7 is checked (ST97). If YES in ST97, the FAX unit 104 is 
instructed to start transmission without any original input processing. 
Whether the FAX unit 104 replies "OK" is checked (ST99). 
If NO in ST97, the control returns to abnormal end UI processing (ST98). 
If transmission is denied in step 99, a transmission suspension flag is set 
(ST100), and the control temporarily branches from the transmission 
processing. 
If YES in step 99, the transmission suspension flag is reset (ST101), and 
transmission condition information such as destination number information, 
transmission original size information, and density information is 
transferred. 
Although no abnormality generally occurs at this time, abnormality 
processing can be performed (ST102 and ST103). 
The FAX unit 104 is instructed to transfer a file. The FAX unit 104 
transfers (n) pages of compressed files in the PM unit 103, and whether 
the processing has normally ended is checked (ST104). 
If NO in ST102, the control returns to abnormal end UI processing (ST103). 
If YES in step 104, the number of input pages is counted down (ST105) to 
check whether the next page exists (ST106). If NO in ST106, the control 
returns to step 104; if YES in ST106, transmission files are erased, and 
garbage collection is performed (ST107) to end the transmission 
processing. 
In processing (D) subsequent to step 30, when the HDD unit 106 exists, the 
FAX unit 104 has the same role as in processing (C), and performs only 
transmission processing. Processing (D) is different from processing (C) 
in that the PM unit 103 performs only image input and file compression, 
and the HDD unit 106 performs file storage, instead of the PM unit 103. 
This will be explained with reference to flow charts in FIGS. 20 and 21. 
At this time, the PM unit 103 performs reception and compression of image 
data, and storage of a file in the HDD unit 106 in units of pages. 
Thereafter, the HDD unit 106 transfers a transmission file from the last 
page to the FAX unit 104 in units of pages. Also at this time, the same 
control as in processing (C) must be executed because transmission 
suspension occurs. Since the HDD unit 106 has a large storage capacity, no 
garbage collection is performed though a file erase is performed. 
More specifically, access to the PM unit 103 is requested, which is retried 
until the PM unit 103 replies "OK" (ST111). 
If access to the PM unit 103 is granted, an original is input to the PM 
unit 103, and compression processing is prepared for (ST112). A 
transmission file area is obtained in the HDD unit 106, a file name is 
initialized, and the number of pages is initialized (ST113). 
The scanner unit 4 is instructed to start scanning an original. If the 
processing normally ends upon reception of this instruction (ST114), the 
PM unit 103 receives image data from the scanner unit 4. 
Also at this time, the reception of data in the PM unit 103, and 
compression of the received data are automatically performed in response 
to an image transfer sync signal from the scanner unit 4. After checking 
whether the image compression has normally ended (ST115), the number of 
input pages is counted up (ST116). 
If NO in step 114 or 115, the control returns to abnormal end UI processing 
(ST116 or ST118). 
Subsequent to step 116, a compressed file is stored in the HDD unit 106, 
and whether the processing has normally ended is checked (ST119). If it is 
determined by this check that the processing has not normally ended, the 
control returns to abnormal end UI processing (ST120). 
If YES in step 116, an original is input to the PM unit 103, compression 
processing is prepared for, and the next page of the FAX transmission file 
area is initialized (ST121). 
The ADF 7 is instructed to feed the next original. If the ADF 7 replies 
"OK" in response to this instruction (ST122), the scanner unit 4 is 
instructed to start scanning the next original. If the processing normally 
ends in response to this instruction (ST123), the PM unit 103 receives 
image data from the scanner unit 4. 
Also at this time, the reception of data in the PM unit 103, and 
compression of the received data are automatically performed by an image 
transfer sync signal from the scanner unit 4. After checking whether the 
image compression has normally ended (ST124), the number of input pages is 
counted up (ST125). A compressed file is stored in the HDD unit 106, and 
whether the processing has normally ended is checked (ST126). If YES in 
ST126 from this check, the control returns to step 121. 
If NO in step 123, 124, or 126, the control returns to abnormal end UI 
processing (ST127, ST128, or ST129). 
If no original D is present on the ADF 7, the ADF 7 does not reply "OK" 
(normal end) for the original feed instruction (ST122). As a result, it is 
determined that no original D is present (ST130). 
If the ADF 7 does not reply "OK" owing to a reason other than the absence 
of the original D, an abnormality such as paper jam may have occurred 
(ST131). 
If YES in ST130, whether the last read original D is normally discharged 
from the ADF 7 is checked (ST132). If YES in ST132, the FAX unit 104 is 
instructed to start transmission without any original input processing. 
Whether the FAX unit 104 replies "OK" is checked (ST133). 
If NO in ST132, the control returns to abnormal end UI processing (ST134). 
If transmission is denied in step 133, a transmission suspension flag is 
set (ST135), and the control temporarily branches from the transmission 
processing. 
If YES in step 133, the transmission suspension flag is reset (ST136), and 
transmission condition information such as destination number information, 
transmission original size information, and density information is 
transferred. 
Although no abnormality generally occurs at this time, abnormality 
processing can be performed (ST137 and ST138). 
The FAX unit 104 is instructed to transfer a file. The FAX unit 104 
transfers (n) pages of compressed files in the PM unit 103, and whether 
the processing has normally ended is checked (ST139). 
If NO in ST139, this step is retried. 
If YES in step 139, the number of input pages is counted down (ST140), and 
whether the next page exists is checked (ST141). If NO in ST141, the 
control returns to step 139; if YES in ST141, erase processing is 
performed for the HDD unit 106 (ST142) to end the transmission processing. 
Reception processing will be described with reference to flow charts in 
FIGS. 22 to 25. 
More specifically, when the control first enters a reception processing 
flow upon reception of a reception notification from the FAX unit 104 
(ST150), it executes the following flow which changes depending on the 
system configuration. 
If the control enters the reception processing flow from step 150 while no 
printer access is granted, and printing is suspended (ST151 and ST152), 
processing when printing is suspended is executed. For example, the 
control advances to step 216 (to be described later). 
In reception processing without any PM unit 103, as processing (A) 
subsequent to step 150, whether printing has been prepared for is inquired 
of the FAX unit 104. If printing has been prepared for, the FAX unit 104 
directly outputs printing data to the printer unit 6, and controls it to 
sequentially print the data until all printing pages are printed. If 
access to the printer unit 6 is requested and cannot be acquired, the FAX 
unit 104 is instructed to store a reception file in a file memory (code 
buffer RAM unit 146) within the FAX unit 104. Immediately after access to 
the printer unit 6 is acquired, the data is printed. When the file memory 
within the FAX unit 104 becomes almost full, a printer access request 
having higher priority, i.e., a strong request requesting access to the 
printer unit 6 even if another processing is stopped is output to print 
the reception file. This will be explained with reference to a flow chart 
in FIG. 23. 
In an actual flow, access to the printer is requested. If access is granted 
(ST153), the printing suspension flag is reset because access to the 
printer unit 6 is acquired. The number of printing pages is initialized 
(ST154) to print. 
If NO in step 153, the FAX unit 104 is instructed to store the reception 
file in the internal file memory. If the FAX unit 104 replies "OK" upon 
reception of this instruction (ST155), the printing suspension flag is 
set, and the control temporarily branches from the reception processing 
(ST159). 
If NO in step 155, whether the file area of the FAX unit 104 is full is 
checked. If the file area is not full (ST156), the control returns to 
abnormal end UI processing (ST157). 
If it is determined in step 156 that the internal file memory is full, and 
the reception file becomes difficult to internally store, a request having 
high priority is output to another processing (ST158). The printing 
suspension flag is set, and the control temporarily branches from the 
reception processing (ST159). 
In printing processing, the printing size, the printing density, and the 
like are inquired of the FAX unit 104 (ST160). In accordance with them, 
the cassette type, the printing density, and the like are set in the 
printer unit 6 (ST161). The FAX unit 104 is instructed to sequentially 
print data from the first page (ST162). When printing has been prepared 
for, the printer unit 6 is activated every page to actually print the data 
(ST163). This operation is continuously performed until all of reception 
pages are printed (ST164 and ST165). Upon completion of printing (ST164), 
the printer unit 6 is released (ST166), and the control branches from the 
reception processing routine. 
If it is determined in step 163 that the processing has not normally ended, 
the control returns to abnormal end UI processing (ST167). 
As processing (B) subsequent to step 153, when the PM unit 103 exists and 
has neither a FAX extended memory for storing a reception file nor the HDD 
unit 106, only printing processing is performed via the PM unit 103, and 
FAX reception and file storage are performed by the FAX unit 104. 
In the above-described routine (A), a printing instruction is directly 
output to the FAX unit 104. Instead of this, reception files are 
transferred to the PM unit 103 one by one, expanded and mapped by the PM 
unit 103, and printed by the printer unit 6. Since the PM unit 103 is also 
commonly used for another processing such as a PPC function, similar to 
the printer unit 6, acquisition and release processes must be performed. 
This will be explained with reference to the flow chart in FIG. 23. 
Access to the printer unit 6 is requested. If access is granted (ST171), 
the printing suspension flag is reset because access to the printer unit 6 
is acquired. The number of printing pages is initialized (ST172). Access 
to the PM unit 103 is requested, which is retried until the PM unit 103 
replies "OK" (ST173). Subsequent printing processing is performed. 
If NO in step 171, the FAX unit 104 is instructed to store a reception file 
in the internal file memory. If the FAX unit 104 replies "OK" upon 
reception of this instruction (ST174), the printing suspension flag is 
set, and the control temporarily branches from the reception processing 
(ST175). 
If NO in step 174, whether the file area of the FAX unit 104 is full is 
checked. If the file area is not full (ST176), the control returns to 
abnormal end UI processing (ST177). 
If it is determined in step 176 that the internal file memory is full, and 
the reception file becomes difficult to internally store, a request having 
high priority is output to another processing (ST178). The printing 
suspension flag is set, and the control temporarily branches from the 
reception processing (ST175). 
In printing processing, the printing size, the printing density, and the 
like are inquired of the FAX unit 104 (ST179). In accordance with them, 
the cassette type, the printing density, and the like are set in the 
printer unit 6 (ST180). 
The file of the (n-1)th page is transferred from the FAX unit 104, and 
written in the file area of the PM unit 103. Whether the processing has 
normally ended is checked (ST181). 
If NO in ST181, this processing is retried. 
If YES in ST181, expansion processing is performed in the PM unit 103 to 
prepare for printing (ST182). 
The printer unit 6 is instructed to start printing, and whether the 
processing normally ends is checked (ST183). If YES in ST183, whether the 
FAX unit 104 has transferred the files of all pages is checked (ST184). If 
NO in ST184, the number of transferred files is counted up (ST185), and 
the control returns to step 181. 
If YES in ST184, the printer unit 6 is released (ST186), the PM unit 103 is 
released (ST187), and the control branches from the reception processing 
routine. 
If NO in step 183, the control returns to abnormal end UI processing 
(ST188). 
As processing (C) subsequent to step 150, when the PM unit 103 exists and 
has a FAX extended memory for storing a reception file but no HDD unit 
106, storage of a reception file and printing processing are performed by 
the PM unit 103, and only FAX reception is performed by the FAX unit 104. 
In this case, all the pages of reception files received by the FAX unit 104 
are temporarily stored in the FAX expanded file memory within the PM unit 
103, and printed from the last one of the received pages. Accordingly, the 
pages can be sequentially sorted from the first page to the last one upon 
printing all the pages. When all the pages are printed in the PM unit 103, 
a simultaneous erase is performed for one communication/reception in which 
the reception files are printed, and processing (garbage collection) of 
shifting the subsequently stored files is performed. By performing this 
processing, a larger file storage capacity can be ensured. This will be 
explained with reference to a flow chart in FIG. 24. 
Access to the PM unit 103 is checked, which is retried until the PM unit 
103 replies "OK" (ST191). 
If YES in ST191, the reception file areas of the PM unit 103 and the FAX 
unit 104 are initialized, and the number of pages is initialized (ST192). 
The file of the (n+1)th page is transferred from the FAX unit 104, and 
written in the file area of the PM unit 103. Whether the processing has 
normally ended is checked (ST193). 
If NO in ST193, this processing is retried. 
If YES in ST193, whether the FAX unit 104 has transferred the files of all 
pages is checked (ST194). If NO in ST194, the number of transferred files 
is counted up (ST195), and the control returns to step 193. 
If YES in ST194, access to the printer unit 6 is requested. If access is 
granted (ST196), acquisition processing for the printer unit 6 is 
performed (ST197), and the printing suspension flag is reset (ST198). 
Depending on the file, the printing size, the density, the read, the 
printer unit 6, and the PM unit 103 are set (ST199). 
Expansion processing is performed for n pages by the PM unit 103 to prepare 
printing (ST200). 
The printer unit 6 is instructed to start printing, and whether the 
processing normally ends is checked (ST201). If YES in ST201, the number 
of printing pages is counted down (ST202), and whether the next page 
exists is checked (ST203). If YES in ST203, the control returns to step 
200; if NO in ST203, reception file erase processing is performed, and 
garbage collection is performed (ST204). The printer unit 6 is released 
(ST205), and the PM unit 103 is released (ST206) to end the transmission 
processing. 
If NO in step 201, the control returns to abnormal end UI processing 
(ST207). 
If NO in step 196, the printing suspension flag is set, and the control 
temporarily branches from the reception processing (ST208). 
As processing (D) subsequent to step 150, in a system with the HDD unit 106 
for storing a file, a reception file stored in the file storage extended 
memory within the PM unit 103 in routine (C) is stored in the HDD unit 
106, and all the pages of reception files are similarly printed from the 
last page. Since the HDD unit 106 has a larger storage capacity, no 
garbage collection is performed. This will be explained with reference to 
a flow chart in FIG. 25. 
The reception file area of the HDD unit 106 is obtained, the file name is 
initialized, and the number of pages is initialized (ST211). 
The FAX unit 104 transfers the file of the (n+1)th page, and writes it in 
the file area of the HDD unit 106. Whether the processing has normally 
ended is checked (ST212). 
If NO in step 212, this processing is retried. 
If YES in step 212, whether the FAX unit 104 has transferred the files of 
all pages is checked (ST213). If NO in ST213, the number of transferred 
files is counted up (ST214), and the control returns to step 212. 
If YES in ST213, access to the printer unit 6 is requested. If the use is 
permitted (ST215), acquiring processing for the printer unit 6 is 
performed (ST216), and the printing suspension flag is set (ST217). Access 
to the PM unit 103 is checked, which is retried until the PM unit 103 
replies "OK" (ST218). 
If YES in ST218, the reception file areas of the PM unit 103 and the FAX 
unit 104 are initialized (ST219). 
Depending on the file, the printing size, the density, the read, the 
printer unit 6, and the PM unit 103 are set (ST220). 
Expansion processing is performed for n pages by the PM unit 103 to prepare 
for printing (ST221). 
The printer unit 6 is instructed to start printing, and whether the 
processing has normally ended is checked (ST222). If YES in ST222, the 
number of printing pages is counted down (ST223), and whether the next 
page exists is checked (ST224). If YES in ST224, the control returns to 
step 221; if NO in ST224, reception file erase processing is performed 
(ST225). The printer unit 6 is released (ST226), and the PM unit 103 is 
released (ST227) to end the transmission processing. 
If NO in step 222, the control returns to abnormal end UI processing 
(ST228). 
If NO in step 215, the printing suspension flag is set, and the control 
temporarily branches from the reception processing (ST229). 
Processing when the functions of the respective system configurations are 
compared by exemplifying the FAX system will be described with reference 
to FIG. 26. 
At option level A, since the FAX system has only the FAX unit 104, all 
operations associated with the FAX must be performed by the FAX unit 104 
alone. 
At option level B, since the expanded memory 104a of the FAX unit 104 is 
additionally arranged, the FAX system is compatible with high-resolution 
input/output and transmission/reception. 
At option level C, since the FAX system also has the PM unit 103, 
compression/expansion can be performed at a high speed by 
inputting/outputting an image via the PM unit 103. Therefore, image 
input/output can be performed at a high speed. By using the editing 
function of the PM unit 103, an editing/transmission/reception function 
can be realized. The image input/output order of the copying machine can 
be changed for FAX transmission and reception. 
At option level D, since the expanded memory 103a of the PM unit 103 is 
additionally arranged, a file can be stored in the PM unit 103. 
Accordingly, the FAX system is compatible with a high resolution without 
any expanded memory 104a of the FAX unit 104. 
At option level E, the FAX system also has the HDD unit 106. By using a 
large storage capacity, a confidential transmission/reception function as 
transmission/reception for a designated end system, and a function such as 
time-designated transmission/reception in which data is 
transmitted/received at time when the line use charge is low can be 
realized in addition to large-capacity transmission/reception. 
Processing that generally changes when the contents explained with 
reference to the flow chart of the FAX task processing shown in FIG. 15 
are applied to not only the FAX unit 104 but also another option will be 
described with reference to FIG. 27. 
In this case, whether the PM unit 103 is arranged, the HDD unit 106 is 
arranged, the expanded memory 103a is arranged in the PM unit 103, the PM 
unit 103 is used, and the file capacity of the expanded memory 103a of the 
PM unit 103 is used and full are checked on the respective stages to 
determine operation control. 
The number of resource channels used and the processing time in each 
processing of the PM unit 103 will be described with reference to FIG. 28. 
Assuming the copying processing time serving as a main function to be 1, 
FAX processing requires 1/4 for normal resolution and 1/2 for high 
resolution. The maximum processing time of editing without any printing is 
1/4 at most. For this reason, when the PM unit 103 is arranged as an 
option, it can perform processing at a much higher speed. 
As has been described above, by optimizing the control depending on the 
configuration of each user, the system can be operated at the highest 
efficiency for each configuration. 
Additional advantages and modifications will readily occur to those skilled 
in the art. Therefore, the invention in its broader aspects is not limited 
to the specific details and representative embodiments shown and described 
herein. Accordingly, various modifications may be made without departing 
from the spirit or scope of the general inventive concept as defined by 
the appended claims and their equivalent.