An image recording apparatus includes a receipt unit for receiving image data, a recorder unit for recording the image data received by the receipt unit, the recorder unit being able to be operated in a dual-side mode for recording image data on both sides of a recording medium and in a single-side mode for recording image data on a single side of the recording medium, and a selector for selecting one of the dual-side mode and the single-side mode.

BACKGROUND OF THE INVENTION 
The present invention relates to an image recording apparatus such as a 
facsimile device. 
Conventionally, a facsimile device including a reader unit, a recorder 
unit, and a controller for controlling these units to transmit/receive 
data to/from another facsimile device is known. 
In the facsimile device, when an original is to be transmitted, one side of 
each original is read one by one by an image sensor provided to the reader 
unit, and read data is converted to predetermined transmission data by the 
controller. The transmission data is transmitted to a destination 
facsimile apparatus through a communication control unit. Upon receipt of 
data, data transmitted from another facsimile device is converted to 
recording data, and the converted data is printed out on one side of a 
recording sheet by the recorder unit. 
In the facsimile device, when a copying operation is to be performed, the 
reader unit reads one side of each original one by one, and the recorder 
unit prints out the read data on one side of a recording sheet. 
However, in the prior art, data which can be recorded on both sides of a 
recording sheet can only be recorded on one side, resulting in waste of 
recording sheets. 
SUMMARY OF THE INVENTION 
The present invention has been made in consideration of the above 
situation, and has as its object to provide an improved image recording 
apparatus. 
It is another object of the present invention to provide an image recording 
apparatus which can save recording sheets, and can easily manage recording 
sheets after recording. 
It is still another object of the present invention to provide an image 
recording apparatus which can efficiently record information. 
It is still another object of the present invention to provide an image 
recording apparatus which can facilitate a recording operation when 
received information is recorded. 
It is still another object of the present invention to provide an image 
recording apparatus which can facilitate processing when a re-recording 
operation is necessary. 
It is still another object of the present invention to provide an image 
recording apparatus which can record received information on both sides of 
a recording medium. 
It is still another object of the present invention to provide an image 
recording apparatus which handles a previously received page of received 
information as a page having a smaller number, and performs dual-side 
recording. 
It is still another object of the present invention which can discriminate 
effective and ineffective pages, and can sequentially record only the 
effective pages on both sides of a recording sheet. 
It is still another object of the present invention to provide an image 
recording apparatus which can discriminate whether a destination apparatus 
has a dual-side reading function or a dual-side recording function. 
It is still another object of the present invention to provide an image 
recording apparatus which can discriminate whether a dual-side reading 
function or a dual-side recording function has been set. 
It is still another object of the present invention to provide an image 
recording apparatus which can detect completion of preparation of a 
recording operation, and can control a recording timing to both sides of a 
recording medium. 
It is still another object of the present invention to provide an image 
recording apparatus which has an image memory of at least two pages, and 
retains received image data until a recording sheet on which the received 
image data is recorded is discharged from a recorder unit. 
The above and other objects and features of the present invention will 
become apparent from the following description taken in conjunction with 
the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a schematic block diagram of a facsimile device 1 according to an 
embodiment of the present invention. 
The facsimile device 1 comprises a reader unit 2 capable of reading both 
sides of an original, a recorder unit 3 capable of recording on both sides 
of a recording sheet, and a controller 4 for controlling the reader unit 2 
and the recorder unit 3. The controller 4 is connected to a communication 
network 6 through a communication control unit 5 incorporating a modem and 
a DSU (digital service unit). 
FIG. 2 is a flow chart showing basic operations, i.e., transmission, 
receipt, and copying operations in a dual-side processing mode in the 
facsimile device 1. 
While the dual-side processing mode is set, an operation mode of the 
facsimile device is designated (S10). When a transmission mode is selected 
(S11), the reader unit 2 reads both sides of an original (S12). The 
communication control unit 5 converts the read data into predetermined 
transmission data, and transmits it to a destination facsimile device 
(S13). When data is transmitted, data for both sides of the original can 
be simultaneously transmitted by using a 2-channel communication 
interface. Alternatively, data for both sides of the original can be 
sequentially transmitted for each side by using a one-channel 
communication interface. 
The above-mentioned operation is sequentially executed for set originals. 
When transmission of all the originals is completed (S14), the processing 
is ended. 
When a copy mode is selected in step S11, the reader unit 2 reads both 
sides of an original, and the recorder unit 3 records the read data on 
both sides of a recording sheet (S16). In dual-side recording at the 
recorder unit 3, in a receipt mode, a previously received page is handled 
as a page having a smaller number (front side), as will be described 
later. In the copy mode, however, front and back sides of dual-side 
recording are determined in correspondence with a set state of originals 
at the reader unit 2. When the copying operation of all the originals is 
completed (S17), the processing is ended. 
Upon receipt of data, the communication control unit 5 receives data from 
an external device (S18). The received data is developed to image data by 
the controller 4 to be converted to recording data. Thereafter, the 
recorder unit 3 records the recording data on both sides of a recording 
sheet (S19). 
In dual-side recording, a previously received page of received data is 
handled as a page having a smaller number. More specifically, the first 
page of received data is recorded on the front side of a first recording 
sheet, and the second page of the received data is recorded on the back 
side of the first recording sheet. Furthermore, for the following received 
data, odd-numbered pages are recorded on front sides of recording sheets, 
and even-numbered pages are recorded on back sides of the recording 
sheets. Thus, the received data can be automatically recorded on both 
sides of each recording sheet without requiring special operations. 
When receipt is completed (S20), the processing is ended. 
FIG. 3 is a side view showing an arrangement of the recorder unit 3. 
The recorder unit is arranged as a laser beam printer, and comprises a 
paper cassette 8 in which recording sheets 7 are set, paper feed rollers 
9, a recording unit 10 consisting of a laser scanner, a photosensitive 
drum, a developing device, and the like, fixing rollers 11, a reversal 
selector 13, a reversal mechanism 14, discharge rollers 40, and a 
discharge tray 41. 
The recorder unit performs recording on both sides of a recording sheet in 
the dual-side recording mode. In the dual-side recording mode, after a 
recording operation is performed on the front side of the recording sheet 
7 by the recording unit 10 and the fixing rollers 11, the recording sheet 
7 guided toward the discharge tray 41 is guided to the reversal mechanism 
14 upon reversal rotation of the discharge rollers 40 and the operation of 
the reversal selector 13, thereby feeding the recording sheet to the 
recording unit 10. Then, a recording operation is performed on a back 
side, and the recording sheet is stacked on the discharge tray 41. 
FIG. 4 is a plan view showing an arrangement of an operation unit of the 
facsimile device 1. 
The operation unit 15 includes a display unit 16, a ten-key pad 17, 
one-touch keys 18, a start key 19, a stop key 20. A mode setting section 
21 includes switches for setting various modes and LEDs for indicating the 
set mode, as shown in FIG. 6. 
In the facsimile device 1, each of reading and recording processing modes 
can be switched from dual-side processing to single-side processing upon 
operation of change over switches 25 and 26, provided to the mode setting 
section 21 (to be described later), for designating modes. 
FIG. 5 is a flow chart for explaining a procedure when the 
dual-side/single-side processing mode is designated. 
In this embodiment, upon designation of the operation of the facsimile 
device (FIG. 2: S10), density, resolution, dual-side/single-side reading, 
and dual-side/single-side recording modes are set. In this case, as 
default data, the density=normal, the resolution=200 dpi, the recording 
mode=dual-side reading mode, and the recording mode=dual-side recording 
mode are set. The device resumes this mode upon power-on or completion of 
transmission, receipt, or copy processing (S31). 
These setting data can be designated by change over switches 23 to 26 of 
the mode setting section 21 shown in FIG. 6, and are indicated by LED 
indicators 27 to 34 arranged in correspondence with the switches 23 to 26. 
The first change over switch 23 is used to designate the resolution. When 
the LED indicator 27 is set ON, the resolution of 200 dpi is designated; 
when the LED indicator 28 is set ON, the resolution of 400 dpi is 
designated. 
The second change over switch 24 is used to designate the density. When the 
LED indicator 29 is set ON, a normal density is designated; when the LED 
indicator 30 is set ON, a dark density is designated. 
The third change over switch 25 is used to designate the dual-side or 
single-side reading mode. When the LED indicator 31 is set ON, the 
dual-side reading mode is designated; when the LED indicator 32 is set ON, 
the single-side reading mode is designated. 
The fourth change over switch 26 is used to designate the dual-side or 
single-side recording mode. When the LED indicator 33 is set ON, the 
dual-side recording mode is designated; when the LED indicator 34 is set 
ON, the single-side recording mode is designated. 
When the setting data are to be changed in step S31, the change over 
switches 23 to 26 are operated to change the setting data (S32). After the 
setting data are changed, ON states of the LED indicators corresponding to 
the change over switches are switched (S33), and an operation mode 
(transmission, copy, or receipt mode) is designated (S34). When no setting 
data are changed, the operation mode is designated in the default state. 
Note that the change over operation of the setting data may be displayed 
not only on the LED indicators but on the display unit 16. 
As described above, in the facsimile device, since the recorder unit has 
the dual-side recording function, image data can be recorded on both sides 
of a recording sheet, thus saving recording sheets. 
Since the number of recorded sheets can be decreased, when the recording 
sheets are filed as a received document, management of the document can be 
facilitated. 
In addition, since a means for selectively switching the 
dual-side/single-side recording mode is added, certain received 
information can be recorded in a mode suitable for the content of the 
received information. 
Since a previously received page of received data is handled as a page 
having a smaller number, no special operation is required in dual-side 
recording, and a dual-side recording operation in receipt can be 
facilitated. 
The facsimile device of the present invention may be arranged so that blank 
pages in recording data in the copy mode or in received data in receipt 
mode are detected, and effective pages other than the blank pages are 
sequentially recorded. 
FIG. 7 is a flow chart showing an operation performed when recording is 
performed for only effective pages, as described above. 
It is checked if each of received pages is an effective page (S41 and S42). 
This decision is achieved by counting the number of changed pixels of 
image data when received data (MMR-encoded data) is decoded into image 
data. When the count value is smaller than a predetermined value, it is 
determined that the corresponding page is a blank page, and is 
ineffective. Note that the above-mentioned processing is executed by the 
controller 4. 
When an effective page is determined, the image data is recorded (S43); 
when an ineffective page is determined, no recording is performed for the 
corresponding page. 
When received data remains (S44), it is checked if the recording operation 
is performed on the front or back side of a recording sheet in step S43 
(S45). If it is determined that the recording operation is performed on 
the front side, the recording sheet is to be reversed to perform a 
recording operation on the back side, and the flow returns to step S41 
(S46). However, if it is determined that the recording operation is 
performed on the back side, the recording sheet is discharged (S47), and 
the flow returns to step S41. Then, a new recording sheet is fed from the 
cassette 8, and a recording operation is performed on this recording 
sheet. 
If it is determined in step S44 that received data is absent, the recording 
sheet is discharged, and processing is ended (S48). 
FIGS. 8(1) to 8(3) are views for, when originals in which blank originals 
are mixed in normal single-side originals are transmitted from a 
transmission side, explaining a case wherein the originals are dual-side 
recorded as they are in comparison with a case wherein only effective 
pages are selected and are dual-side recorded. 
As shown in FIG. 8(2), when originals are dual-side recorded as they are, 
recording sheets include those whose back sides are blank. However, when 
the effective pages are selected and are dual-side recorded, recording 
sheets can be subjected to dual-side recording without forming a blank 
side. 
This operation is similarly performed in the copy mode. 
As described above, in this facsimile device, of received information or 
read image information, only pages determined effective pages are 
sequentially recorded on both sides of a recording sheet. Therefore, waste 
of recording sheets can be prevented without forming a blank page, and 
received information can be efficiently recorded. 
The facsimile device of the present invention may be arranged to be able to 
confirm if a destination device has a dual-side reading function or a 
dual-side recording function. This embodiment will be described below. 
FIG. 9 is a side view showing an arrangement of a reader unit 2. 
In the reader unit 2, originals are set on an original table while being 
stacked in the order starting from the lower side. The reading unit 2 
comprises an ADF unit 208 consisting of separation and paper feed rollers, 
an original reading unit 209 for reading front and back sides of an 
original 207, and discharge rollers 210 for feeding the original 207 
discharged from the original reading unit 209 onto a discharge tray 211. 
The original reading unit 209 has two contact image sensors (to be referred 
to as contact sensors hereinafter) 212 and 213 which oppose the front and 
back sides of the original 207, respectively. The contact sensors 212 and 
213 read images formed on both sides of the original 207 at a time. The 
contact sensors 212 and 213 respectively read the front and back sides of 
the original 207. The contact sensor 212 arranged at the lower side in 
this embodiment is arranged at a position where the original 207 arrives 
earlier than the position of the contact sensor 213. 
FIG. 10 is a flow chart showing an operation of the reader unit 2. 
When a reading instruction is input from the controller 4 (S51), the 
original 207 is conveyed to the original reading unit 209 by the ADF unit 
208 (S52). When the original 207 arrives the front-side contact sensor 212 
(S53), the sensor 212 starts reading of the front side of the original 
(S54). When the original 207 arrives the back-side contact sensor 213 
(S55), the sensor 213 starts reading of the back side of the original 
(S56). 
When reading of both sides is completed (S57), the read original 207 is 
stacked on the discharge tray 211 (S58). 
The above operation is repeated. When there is no original 207 on the 
original table (S59), end processing for informing the end of operation is 
performed by enabling a buzzer or displaying a message (S60), and the 
original reading operation is ended. 
FIG. 11 is a side view showing another arrangement of a reader unit. 
In a reader unit 202a, originals 207 are set while being stacked in the 
order starting from the upper side. The reader unit 202a comprises an ADF 
unit 208a, an original reading unit 209a, and discharge rollers 210a. An 
original 207 is turned over by a guide 214, and is then discharged on a 
discharge tray 211a. In this case, in the original reading unit 209a, a 
contact sensor 212a for reading the front side of the original 207 is 
arranged at an upper position, and a contact sensor 213a for reading the 
back side of the original 207 is arranged at a lower position. In this 
embodiment, the front-side contact sensor 212a is arranged at a position 
where the original arrives earlier than the position of the back-side 
contact sensor 213a. The dual-side reading operation of the original 207 
is performed in the same manner as in FIG. 10. 
Note that in place of the contact sensors in the reading unit, image 
sensors comprising optical systems each including a lens, a mirror, and a 
CCD may be used. 
FIG. 12 is a plan view showing an arrangement of an operation unit of the 
facsimile device 1 of this embodiment. 
An operation unit 215 includes a display unit 216, a ten-key pad 217, a 
one-touch dial key 218, a start key 219, and an inquiry key 220. 
Of these keys, the inquiry key 220 is used to inquire of a destination 
device whether or not a destination facsimile device has a dual-side 
reading function or a dual-side recording function and whether or not the 
destination apparatus is set in a mode for executing the dual-side 
processing when the destination device has the dual-side function. 
FIG. 13 is a flow chart showing an inquiry procedure. 
The inquiry key 220 is depressed (S61), and a destination facsimile (FAX) 
number is then input using the ten-key pad 217 (S62). After it is 
confirmed that the input number is correct (S63), the start key 219 is 
depressed (S64), thereby starting inquiry software (S65). In addition, the 
contents of the processing functions and setting mode of the destination 
facsimile device are displayed on the display unit 216 (S66). 
The inquiry software in step S65 will be described below. 
FIG. 14 is a chart showing inquiry procedures in a G3 facsimile device. 
Procedures and signals shown in FIG. 14 comply with the CCITT 
recommendation T30, and a detailed description thereof will be omitted. 
In FIG. 14, signals NSF and NSS are used for informing a non-standard 
function to a destination facsimile device. More specifically, in an 
information field of each of these signals, first and second octets are 
assigned to a CCITT member code, a third octet is assigned to a home maker 
code, and a fourth octet is assigned to a free area, as shown in FIG. 15. 
Thus, a dual-side function identifier code indicating the presence/absence 
of the dual-side function and a mode identifier code indicating a mode 
when the device has the dual-side function are set in the free area. For 
example, as shown in FIGS. 16(1) and 16(2), when the dual-side function 
identifier code is "1", this defines that the device has the dual-side 
function; when it is "0", defines that the device has no dual-side 
function. When the mode identifier code is "1", this defines that the 
dual-side mode is set; when it is "0", this defines that the single-side 
mode is set. 
A case will be exemplified below wherein the transmission side requests 
dual-side recording. In this case, when the received signal NSF indicates 
the presence of the dual-side recording function and the single-side mode, 
an instruction for performing recording in the dual-side mode (i.e., the 
dual-side function identifier code=1 and the mode identifier mode code=1) 
is superposed on the signal NSS and is transmitted. 
In one method of designating the recording mode of the destination 
facsimile device, a destination mode instruction switch 225 is arranged in 
addition to a resolution instruction switch 223, a density instruction 
switch 224, and the like, as shown in FIG. 17, so that the identifier code 
of the signal NSS can be changed over upon operation of the switch 225. 
Note that LED indicators 227 to 232 are arranged two each in 
correspondence with the instruction switches 223 to 225. A desired mode is 
set while observing ON states of the indicators 231 and 232 according to 
the depression state of the destination mode instruction switch 225. These 
switches are arranged on the operation unit shown in FIG. 12. 
When it is identified in communication that the transmission side facsimile 
device has the dual-side reading function and the receiving side facsimile 
device has the dual-side recording function, the transmission side device 
instructs one of the dual-side and single-side modes for image 
transmission to the receiving side device, and the receiving side device 
changes over the dual-side/single-side recording mode on the basis of this 
instruction. In this manner, receipt in a state requested by the 
transmission side is allowed. 
In this embodiment, the G3 facsimile device has been exemplified. The same 
applies to a G4 facsimile device. 
FIG. 18 is a chart showing inquiry procedures in a G4 facsimile device. 
In this case, a signal CSS (session start command) is sent in a session 
layer, and a signal RSSP (session start response) is received. FIGS. 19(1) 
and 19(2) show formats of the signals CSS and RSSP. As shown in FIGS. 
19(1) and 19(2), the signal RSSP includes characteristic information of a 
destination terminal. The presence/absence of the dual-side function of a 
receiving side facsimile device and a setting mode when the dual-side 
function is present are identified from a dual-side function identifier 
code and a mode identifier code of non-standard terminal functions. More 
specifically, as shown in FIGS. 20(1) and 20(2), when the dual-side 
function identifier code is "00", the absence of the dual-side recording 
function is determined; when it is "01", the presence of the dual-side 
recording function is determined. 
A recording mode can be designated in a destination facsimile device in the 
same manner as in the G3 facsimile device. 
The facsimile device may be arranged so that an instruction from a 
transmission side device is ignored at a receiving side device, and the 
receiving side device performs recording without changing its mode. 
FIG. 21 is a flow chart showing an operation of a receiving side facsimile 
device in this case. 
The receiving side device receives the above-mentioned 
dual-side/single-side mode instruction from the transmission side device 
(S61), and checks if the recording mode is changed in accordance with the 
instruction (S62). More specifically, in this case, an instruction switch 
226 is added, as indicated by a broken line in FIG. 17, so that the 
receiving side device can select whether or not the instruction from the 
transmission side device is ignored. The processing mode is determined by 
referring to setting of this mode setting switch. 
When the instruction from the transmission side device is ignored, the 
dual-side/single-side mode is not changed, and a recording operation is 
performed in the setting mode. When the dual-side/single-side mode is 
changed in accordance with the instruction from the transmission side 
device, if the instruction from the transmission side indicates the 
dual-side mode (S63), the dual-side recording mode is set (S64); if the 
instruction indicates the single-side mode, the single-side recording mode 
is set (S65), thus performing a recording operation. 
The dual-side/single-side change instruction described above can be issued 
from a transmission side device even if the transmission side device has 
no dual-side function. For example, this can be realized by arranging a 
destination mode instruction switch, as shown in FIG. 17. 
The dual-side/single-side change instruction described above from a 
transmission side device may be issued in units of pages of transmission 
originals. In this case, mode instruction information is transmitted 
between pages of image information, and a receiving side device changes 
the dual-side/single-side mode in response to this instruction. 
FIGS. 22(1) and 22(2) are flow charts showing an operation when a 
dual-side/single-side mode is changed in units of pages. FIG. 22(1) shows 
an operation at a transmission side, and FIG. 22(2) shows an operation at 
a receiving side. 
After the transmission side device transmits mode instruction information 
(S71), it transmits image information for one page (S72). If transmission 
is not completed yet (S73), setting of the mode instruction information is 
changed as needed (S74), and the flow returns to step S71 to transmit the 
mode instruction information. 
The receiving side device receives the mode instruction information (S81), 
and changes a mode based on the mode instruction information (S82). The 
receiving side device receives image information for one page in 
accordance with the changed mode (S83). If receipt is not completed yet 
(S84), the flow returns to step S81 to receive the next mode instruction 
information. 
FIG. 23 shows a format of the mode instruction information. 
The mode instruction information includes a dual-side/single-side 
identifier in a user readable comment area present in a page descriptor of 
a presentation layer. 
In FIGS. 22(1) and 22(2), the mode instruction information is transmitted 
regardless of the presence/absence of mode change. However, the mode 
instruction information may be transmitted when a mode is to be changed. 
When received data or read data are sequentially recorded on both the front 
and back sides of a recording sheet, the facsimile device may be arranged 
so that recording data for the front and back sides are supplied upon 
detection of completion of preparation of a recording operation. 
FIG. 24 shows an arrangement of this embodiment, and the same reference 
numerals in FIG. 24 denote the same parts as in FIG. 3. A head bearing 
sensor 50 detects the leading end of a recording sheet fed from a cassette 
8 or a reversal mechanism 14, and then causes a controller 4 to supply 
image data. 
FIG. 25 is a timing chart for explaining timings when a recording operation 
is performed for each page of recording sheets in the recorder unit 
described above. 
In FIG. 25, a one-page recording operation requires a time T.sub.1. After a 
recording operation of a front side is completed, a wait time T.sub.2 is 
required until a recording sheet is reversed and a recording operation of 
a front side is started. After the recording operation of the back side is 
completed, a wait time T.sub.3 is required until the next recording sheet 
is fed, and the recording operation of the front side is started. As shown 
in FIG. 25, since the recording operations for the front and back sides of 
a recording sheet have different convey paths of the recording sheet, the 
wait times T.sub.2 and T.sub.3 are often different from each other. In the 
facsimile device of this embodiment, the head bearing sensor 50 is 
arranged at an entrance of a recording unit 10, as described above, and an 
output timing of image data from the controller 4 is controlled on the 
basis of the detection timing, thereby assuring recording operations at 
proper timings on both the front and back sides of the recording sheets. 
FIG. 26 is a timing chart showing an operation of the facsimile device of 
this embodiment. 
The facsimile device starts receipt by calling (S91). The device receives 
data for one page, and stores the received data in an image memory in the 
controller 4 (S92). The device performs a sheet feeding operation of a 
recording sheet (S93). The sheet feeding operation is performed from the 
paper cassette 8 when a side to be recorded is a front side or from the 
reversal mechanism 14 if it is a back side. The sheet feed operation is 
continued until a head bearing operation is completed in response to the 
output from the head bearing sensor 50 (S94). With the operations in steps 
S93 and S94, image data can be supplied to the recorder unit at the same 
timing even when a recording operation is performed on either the front or 
back side of a recording sheet. The image data stored in step S92 is read 
out from the image memory, and is supplied to the recorder unit in 
accordance with the head bearing timing. The recorder unit records the 
image data (S95). When all the data are received (S96), the recording 
sheet is discharged (S97), and receipt is ended (S98). If the next page is 
detected in step S96 and the recorded side is a front side (S99), the 
recording sheet is reversed by the reversal mechanism 14 (S100); if the 
recorded side is a back side, the recording sheet is discharged (S101). 
Thereafter, the flow returns to step S92 to receive the next page. 
In this manner, in the facsimile device of this embodiment, since image 
data is sent to the recorder unit on the basis of the detection timing of 
the head bearing sensor 50, a recording operation can be started at a 
proper timing although start timings of recording operations for the front 
and back sides of a recording sheet are different from each other. Thus, a 
head bearing error for each page can be eliminated. 
Note that the number of head bearing sensors 50 is not limited to one. For 
example, a plurality of sensors may be used in correspondence with the 
front and back sides. 
The facsimile device may be arranged so that image data for the front and 
back sides are held until a recording sheet is discharged. That is, in a 
copy mode, image data for both sides of an original read by a reader unit 
2 are stored in an image memory in a recorder unit 3 as a pair of image 
data of two pages, and are held until a copying operation of the 
corresponding original is completed and a recording sheet is discharged. 
In a receipt mode, received image data of two pages are paired and stored 
in the image memory. The image data are held until dual-side recording of 
the image data of two pages is completed and a recording sheet is 
discharged. When a paper jam occurs during recording and a re-recording 
operation must be performed, the image data of two pages stored in the 
image memory are read out again to start a recording operation on a new 
recording sheet. Thus, a proper recording operation can be performed 
without omission of pages. 
FIG. 27 shows an arrangement of this embodiment, and the same reference 
numerals in FIG. 27 denote the same parts as in FIG. 3. A detection sensor 
42 detects that a recording sheet is discharged. As will be described 
later, image data of two pages, i.e., the front and back sides are held 
until this sensor detects that a recording sheet is discharged. 
In the facsimile device for performing dual-side recording, when a receipt 
operation is normally performed, image data can be in the image memory in 
units of pages, and can be sequentially recorded on the front and back 
sides of recording sheets, as shown in FIG. 28(1). As shown in FIG. 28(2), 
when a paper jam occurs while a recording operation is performed on the 
front side of a recording sheet, the recording operation can be restarted 
from data for the front side during the recording operation. Therefore, 
the image memory need only have a capacity of one page. However, as shown 
in FIG. 28(3), when a paper jam occurs while a recording operation is 
performed on the back side of a recording sheet, a recording operation 
must be restarted from not data for the back side during the recording 
operation but data for the front side which has already been recorded. 
Therefore, in this case, received data for the front side must be held 
until a recording operation of the back side is completed. In the 
facsimile device of this embodiment, the image memory of two pages is 
prepared, and even when a paper jam occurs during a recording operation of 
the back side of a recording sheet, the recording operation can be 
restarted by processing unique to the receiving side, as will be described 
later. 
FIG. 29 is a flow chart showing an operation of the facsimile device when a 
re-recording operation is performed. 
The facsimile device starts receipt by calling (S111) to receive data of 
one page as front-side data, and stores the received data in the image 
memory in the controller 4 (S112). The device records the image data 
stored in step S112 on the front side of a recording sheet, and then 
reverses the recording sheet (S113). When a jam occurs in this state 
(S114), the device waits until jam processing is completed and the 
operation is revived (S120). Thereafter, the flow returns to step S113. 
If no jam occurs in step S113, it is checked if all the pages are received 
and recorded (S115). If it is determined that receipt and recording of all 
the pages are completed, the recording sheet is discharged, and receipt is 
ended (S122). If it is determined in step S115 that receipt and recording 
of all the pages are not completed yet, it is checked if data for the back 
side has been received (S116). If NO in step S116, the data for the back 
side is received and is stored in the image memory (S117). The image data 
stored in step S117 is recorded on the back side of the recording sheet, 
and the recording sheet is discharged (S118). If a jam occurs in this 
state (S119), the device waits until jam processing is completed and the 
operation is revived (S120). Thereafter, the flow returns to step S113. If 
no jam occurs, it is checked if all the pages are received and recorded 
(S121). If it is determined that receipt and recording of all the pages 
are completed, the recording sheet is discharged, and receipt is ended 
(S122). If NO in step S121, the image memory is cleared, and the flow 
returns to step S112. 
In this facsimile device, the image memory having a capacity of two pages 
retains image data of two pages until a recording sheet is discharged. 
Even if a jam occurs during recording and a re-recording operation is 
necessary, images of two pages can be easily reproduced by processing 
unique to the receiving side device, and a proper recording operation can 
be performed without omission of pages. 
In the above embodiments, the dual-side processing function is provided to 
both the reader unit and the recorder unit. However, a sufficient effect 
can be expected if the dual-side processing function is provided to only 
the recorder unit. 
In the above embodiments, the laser printer with the reversal mechanism has 
been exemplified as the recorder unit. However, the recorder unit may be 
of a thermal transfer type or an ink-jet type as long as data can be 
recorded on both sides of a recording sheet. Alternatively, a recording 
operation may be performed from both sides without reversing a recording 
sheet. 
The recorder unit need not be arranged exclusively for the dual-side 
recording mode. The recorder unit may be arranged as one which can be 
selectively used in the dual-side recording mode and the single-side 
recording mode.