Abstract:
A communication apparatus includes a receptacle for containing a print material, a receiver for receiving an image through a communication line, a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet, and a detector for detecting the print material supply mark. The communication apparatus further includes a controller for selecting, in response to a user&#39;s operation, a mark-on state in which the printing section is allowed to print the print material supply mark and a mark-off state in which the printing section is prohibited from printing the print material supply mark.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a communication apparatus which is capable of receiving an image transmitted via a communication line and printing the received image on a recording paper sheet. 
     2. Description of the Related Art 
     A facsimile machine is known which is provided with an ink-jet printer. For preventing a deterioration of the printing quality due to clogging of an ink flow path (hereafter referred to as “ink clog”) in such a facsimile machine, the printer is controlled to print an ink supply mark (e.g. a black dot) at the trailing edge of a recording paper sheet, and a mark sensor such as a reflection type photoelectric tube is provided to detect the ink supply mark. If the central processing unit (CPU) of the facsimile machine determines that the detection of the mark sensor shows a deterioration of the printing quality, the CPU notifies such a deterioration at a display of the facsimile machine while also shifting the operation of the facsimile machine to the memory reception mode. 
     However, the prior art facsimile machine is disadvantageous in that an ink supply mark (not forming a part of the fax-received image) is printed on a recording sheet unless an ink clog occurs, and the user has no option of avoiding such a printing mode. Indeed, some users consider that an ink supply mark should not be printed on a recording sheet. 
     Further, the prior art facsimile machine has been also found disadvantageous in that an ink supply mark may be erroneously detected by the mark sensor when disturbing light enters from outside, and that the memory for backup of the fax-received data may become readily full due to frequent memory reception of the fax data. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a communication apparatus by which a user can optionally select whether to print an ink (print material) supply mark on each recording sheet or not. 
     Another object of the present invention is to provide a communication apparatus which is capable of preventing an erroneous operation even when disturbing light enters from outside before or in the course of printing a fax received image. 
     A further object of the present invention is to provide a communication apparatus which is capable of conveniently preventing a memory from becoming full. 
     Still another object of the present invention is to provide a communication apparatus which is capable of prompting the user to take appropriate actions for preventing a memory from becoming full. 
     According to a first aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for detecting the print material supply mark; and a controller for selecting, in response to a user&#39;s operation, a mark-on state in which the printing section is allowed to print the print material supply mark and a mark-off state in which the printing section is prohibited from printing the print material supply mark. 
     With the communication apparatus described above, the user has the option of selecting the mark-on state and the mark-off state. If the user selects the mark-off state, no ink supply mark is printed on the recording sheet for satisfying the user&#39;s preference. If the user selects the mark-on state, an ink supply mark is printed on each recording sheet for detection by the mark sensor, whereby appropriate steps may be taken at the time of an ink clog or an ink run-out. 
     The selection of the mark-on state or the mark-off state may be performed by operating the keys of an operation section. For instance, two specific keys of the operation section may be pressed together to switch from the mark-on state to the mark-off state or vice versa. However, such a manner of operation is not limitative. 
     Typically, the communication apparatus comprises a facsimile machine. Alternatively, however, the communication apparatus may be a multi-function apparatus which has a fax transmission function, a printing function, an image scanning function and a copying function under the control of a computer. 
     Preferably, the print material may be an ink for monochrome printing or color printing. The ink may be typically in the form of a liquid, but it may be a solid ink which is melted at the time of printing. Alternatively, the print material may be in the form of powder such as toner for electrophotographic process. 
     The receptacle for the print material may be a cartridge which is replaced as a unit. A plurality of cartridges may be removably mounted at the printing section for purposes of color printing. Alternatively, the receptacle may be a fixed container to which an amount of the print material is replenished at the time of exhaustion. 
     The communication line may comprise a public or private communication line which may be wired or wireless. 
     Typically, the printing section may comprise an ink jet printhead. Alternatively, the printing section may incorporate an electrophotographic process cartridge. 
     The print material supply mark printed by the printing section may be a black dot for example. However, the size, color and configuration of the print material supply mark may be optionally selected. 
     The detecting unit may comprise a reflection type photoelectric tube, but this is not limitative. 
     The controller may comprise a CPU of the communication apparatus which performs various function on the basis of various programs and data read out from a ROM and/or an EEPROM. 
     According to a preferred embodiment, the communication apparatus further comprises a memory for storing the received image, and the controller controls the memory to store the received image while the printing section is held in the mark-off state. 
     The memory for this purpose may comprise a RAM. However, other memory such as a flash memory or a hard disk is also usable for the storage of the backup data. 
     The controller is further being capable of selecting, in response to a user&#39;s operation performed in the mark-off state, a backup-on state in which the memory is controlled to store the received image and a backup-off state in which the memory is controlled not to store the received image. 
     According to a second aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; and a controller for controlling the printing section to perform successive steps of printing the received image on the recording sheet regardless of detection by the detecting unit with respect to the print material supply mark if the detecting unit detects the disturbing light immediately before starting the printing. 
     The detecting unit for the second aspect of the present invention may comprise a single sensor which is commonly used for detecting the print material supply mark and the disturbing light. Alternatively, the detecting unit may comprise two different sensors; one for detecting the print material supply mark and the other for detecting the disturbing light. 
     Again, the communication apparatus may further comprise a memory for storing the received image as backup data. In this case, the controller selects a backup-on state and a backup-off state in response to a user&#39;s operation. In operation, the controller held in the backup-on state controls the memory to store the received image if the detecting unit detects the disturbing light immediately before starting the printing. Conversely, if the detecting unit does not detect the disturbing light immediately before starting the printing, the controller held in the backup-on state controls the memory not to store the received image. Further, the controller held in the backup-off state controls the memory not to store the received image regardless of detection by the detecting unit with respect to the disturbing light. 
     According to a third aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; and a controller for controlling the printing section to stop printing the received image while controlling the memory to store the received image if the print material supply mark is not normally detected by the detecting unit in the course of the printing; wherein the controller controls the printing section to stop printing the received image while controlling the memory to store the received image regardless of detection by the detecting unit with respect to the print material supply mark if the detecting unit detects the disturbing light in the course of the printing. 
     According to a fourth aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; and a controller for selecting a backup-on state and a backup-off state in response to a user&#39;s operation, the controller also selecting, in response to another user&#39;s operation, a mark-on state in which the printing section is allowed to print the print material supply mark and a mark-off state in which the printing section is prohibited from printing the print material supply mark; wherein the controller performs four different control modes in accordance with different combinations of the backup-on state, the backup-off state, the mark-on state and the mark-off state. 
     In a first control mode performed by the controller which is held in the backup-on state and the mark-on state, the following steps take place. If the detecting unit detects the disturbing light immediately before starting the printing, the controller controls the memory to store the received image in addition to controlling the printing section to print the received image and the print material supply mark. If the print material supply mark is normally read by the detecting unit in the absence of the disturbing light in the course of the printing, the controller controls the memory not to store the received image while controlling the printing section to print the received image and the print material supply mark. If the print material supply mark is not normally read by the detecting unit in the absence of the disturbing light in the course of the printing, the controller controls the memory to store the received image while controlling the printing section to stop printing the received image. If the detecting unit detects the disturbing light in the course of the printing, the controller controls the memory to store the received image while controlling the printing section to stop printing the received image regardless of detection by the detecting unit with respect to the print material supply mark. 
     In a second control mode performed by the controller which is held in the backup-off state and the mark-on state, the following steps take place. The controller controls the memory not to store the received image but controlling the printing section to print the received image and the print material supply mark regardless of detection by the detecting unit with respect to the disturbing light. If the print material supply mark is not normally read by the detecting unit in the absence of the disturbing light in the course of the printing, the controller controls the memory to store the received image while controlling the printing section to stop printing the received image and the print material supply mark. 
     In a third control mode performed by the controller which is held in the backup-on state and the mark-off state, the controller controls the memory to store the received image while controlling the printing section to print the received image without printing the print material supply mark regardless of detection by the detecting unit with respect to the disturbing light. 
     In a fourth control mode performed by the controller which is held in the backup-off state and the mark-off state, the controller controls the printing section to print the received image without printing the print material supply mark and without causing the memory to store the received image regardless of detection by the detecting unit with respect to the disturbing light. 
     According to a fifth aspect of the present invention, there is provided a communication apparatus comprising: a display section for displaying various kinds of information; a receptacle for containing a print material; a receiver for receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; and a controller for selecting a mark-on state in which the printing section is allowed to print the print material supply mark and a mark-off state in which the printing is section is prohibited from printing the print material supply mark; wherein the controller controls the memory to store the received image in addition to controlling the printing section to print the received image when the mark-off state is selected or when the detecting unit detects the disturbing light immediately before the printing, the controller also controlling the display section to display a print result inquiry after completion of the image reception by the receiver if the received image is stored in the memory, the controller further controlling the memory to delete the backup data in response to a print-OK input by a user. 
     Preferably, the communication apparatus may further comprise a cleaner for cleaning a supply path for the print material. In this case, the controller controls the cleaner to clean the supply path in response to a print-NG input by the user, and the controller also controls the printing section to print out the backup data after the cleaning. 
     According to a sixth aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; and a controller for controlling the memory and the printing unit in accordance with the detection of the detecting unit; wherein the controller checks a remaining capacity of the memory before storing the received image, the controller also deleting those of the backup data which have been already printed out when the remaining capacity of the memory is found to be no more than a predetermined amount. 
     According to a seventh aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; a cleaner for cleaning a supply path for the print material; and a controller for controlling the memory to store or not to store the received image in accordance with the detection of the detecting unit, the controller further controlling the printing section to print out any remainder of the of backup data the memory on the recording sheet after controlling the cleaner to clean the supply path. 
     Preferably, the controller selects, in response to a user&#39;s operation, a mark-on state in which the printing section is allowed to print the print material supply mark and a mark-off state in which the printing section is prohibited from printing the print material supply mark, and the controller controls the memory to store or not to store the received image in accordance with the detection of the detecting unit and the selection of the mark-on state or the mark-off state. 
     In one example, the controller controls the cleaner to clean the supply path in response to a user&#39;s operation. 
     In another example, the controller controls the cleaner to automatically clean the supply path at a predetermined time interval. 
     In still another example, the print material is an ink contained in an ink cartridge as the receptacle, and the controller controls the cleaner to clean the supply path automatically upon replacement of the ink cartridge. 
     According to an eighth aspect of the present invention, there is provided a communication apparatus comprising: a receptacle for containing a print material; a receiver for receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; a cleaner for cleaning a supply path for the print material; and a controller for selecting, in response to a user&#39;s operation, a mark-on state in which the printing section is allowed to print the print material supply mark and a mark-off state in which the printing section is prohibited from printing the print material supply mark, the controller controlling the memory to store or not to store the received image in accordance with the detection of the detecting unit and the selection of the mark-on state or the mark-off state; wherein the controller held in the mark-on state controls the printing section to print out any remainder of the backup data of the memory on the recording sheet after controlling the cleaner to clean the supply path, the controller held in the mark-off state preventing the printing section from printing out any remainder of the backup data of the memory on the recording sheet even after controlling the cleaner to clean the supply path. 
     According to a ninth aspect of the present invention, there is provided a communication apparatus comprising: a display section for displaying various kinds of information; a receptacle for containing a print material; a receiver For receiving an image through a communication line; a memory for storing the received image as backup data; a printing section for printing the received image on a recording sheet with the print material while also printing a print material supply mark at an edge portion of the recording sheet; a detecting unit for optically detecting the print material supply mark and for optically detecting disturbing light; and a controller for controlling the memory and the printing section in accordance with the detection of the detecting section; wherein the controller controls the display section to display a print request inquiry for asking a user whether to print out the backup data of the memory, the controller also controlling the printing section to print out the backup data when the user requests so in response to the print request inquiry. 
     Further, the controller may also control the display section to display a print-busy indication while the printing section prints out the backup data of the memory in response to the user&#39;s print request. 
     Preferably, the controller controls the display section to display a print result inquiry for asking the user as to print results after the printing section prints out the backup data in response to the user&#39;s print request. Further, the controller also controls the memory to delete the backup data when the user makes a print-OK input in response to the print result inquiry. 
     Advantageously, the controller controls the display section to display a deletion inquiry for asking the user whether to delete the backup data when the user requests no printing of the backup data in response to the print request inquiry. Further, the controller also controls the memory to delete the backup data when the user requests so in response to the delete inquiry. 
     It is additionally advantageous if the controller controls the display section to display a no-data indication when the memory stores no backup data. 
     Moreover, the controller may control the memory to delete the backup data if no disturbing light is detected by the detecting unit while the printing section prints out the backup data in response to the user&#39;s print request. 
     Other objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiment given with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a circuit block diagram of a facsimile machine as an example of communication apparatus embodying the present invention; 
     FIG. 2 is a schematic perspective view showing a printing section incorporated in the same facsimile machine; 
     FIG. 3 is a flow diagram illustrating a fax reception process of the same facsimile machine shown; 
     FIGS. 4 and 5 represent, in combination, a flow diagram illustrating a first control process of the same facsimile machine; 
     FIG. 6 is a flow diagram illustrating a second control process of the same facsimile machine; 
     FIG. 7 is a flow diagram illustrating a third control process of the same facsimile machine; 
     FIG. 8 is a flow diagram illustrating a fourth control process of the same facsimile machine; 
     FIG. 9 is a flow diagram illustrating a print result inquiry process of the same facsimile machine; 
     FIGS. 10A and 10B are views showing two different result inquiry indications displayed in the print result inquiry process; 
     FIG. 11 is a flow diagram illustrating an ink clog process of the same facsimile machine; 
     FIG. 12 is a flow diagram illustrating an ink run-out process of the same facsimile machine; 
     FIG. 13 is a flow diagram illustrating a post-cleaning process of the same facsimile machine; 
     FIG. 14 is a flow diagram illustrating a manual data deletion process of the same facsimile machine; 
     FIGS. 15A and 15B are views showing two different print request inquiry indications displayed in the manual data deletion process; 
     FIG. 16 is a table showing an example of activity report which may be referred to by the user in deciding whether to print out the backup data in the manual data deletion process; 
     FIG. 17 is a view showing a print-busy indication displayed while printing out the backup data in the manual data deletion process; 
     FIGS. 18A and 18B are views showing two different deletion inquiry indications displayed in the manual data deletion process; and 
     FIG. 19 is a view showing a no-backup indication displayed in the manual data deletion process when there is no backup data in the memory. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 
     Reference is first made to FIG. 1 which is a circuit block diagram showing a facsimile machine as an example of a communication apparatus embodying the present invention. This facsimile machine comprises a CPU (central processing unit)  1 , an NCU (network control unit)  2 , a RAM (random access memory)  3 , a modem (modulator-demodulator)  4 , a ROM (read-only memory)  5 , an EEPROM (electrically erasable and programmable ROM)  6 , a gate array  7 , a codec (coder-decoder)  8 , and a DMAC (direct memory access controller)  9 . Further, the facsimile machine also comprises a reading section  11 , a printing section  12 , an operation section  13 , and a display section  14 . 
     The CPU  1 , the NCU  2 , the RAM  3 , the modem  4 , the ROM  5 , the EEPROM  6 , the gate array  7 , the codec  8  and the DMAC  9  are connected to each other via bus lines (digital lines). The bus lines include data bus lines, address bus lines and control signal bus lines. The gate array  7  is connected to the reading section  11 , the printing section  12 , the operation section  13  and the display section  14 , respectively. 
     The CPU  1  provides an overall control of the facsimile machine as a whole. 
     The NCU  2  is connected to a telephone line  21  for providing network control. The NCU  2  is also connected to the modem  4  and the codec  8  through an analog line, respectively. 
     The RAM  3 , which may be provided with a power backup of a battery (e.g. a rechargeable battery), stores digital data such as fax-received data and voice data (received in an automatic answering mode). Of course, an additional RAM or RAMs may be provided to increase the capacity of data storage. 
     The modem  4  modulates the transmitting codes and demodulates the received codes. 
     The ROM  5  stores various programs or the like as required for controlling the facsimile machine, whereas the EEPROM  6  stores registered data (e.g. shortcut dials) and/or flags. 
     The gate array  7  functions as an I/O interface (input/output interface) for the CPU  1  for data transmission to and/or from the reading section  11 , the printing section  12 , the operation section  13  and the display section  14 . The gate array  7  also provides analog-to-digital conversion with respect to the image signals from the reading section  11  while providing various kinds of image processing. 
     The codec  8  performs coding of the transmitting image data and decoding of the received image data, for example. The codec  8  also converts the pre-recorded reply message (digital voice data) from the RAM  3  into analog voice signals for supply to the NCU  2  while converting the received message (analog voice signals) from the NCU  2  into digital voice data for storage in the RAM  3 . 
     The DMAC  9  provides memory access control with respect to the RAM  3  for data reading and writing for example. 
     The reading section  11  includes a light source (not shown) and an image sensor (not shown) such as a color CCD image sensor (CCD: charge-coupled device) for reading out the image data from a document (or image carrying) paper sheet (not shown). The reading section  11  also includes a plurality of rollers for transferring the document sheet. 
     As shown in FIG. 2, the printing section  12  may comprise a color ink jet printer for example. In the illustrated embodiment, the ink jet printer includes a printhead  120  having a plurality of nozzle ports  120   a , and a plurality of ink cartridges  121  removably connected to the printhead  120 . For color printing, at least three of the ink cartridges  121  contains ink of a different color, whereas one of the ink cartridges  121  contains black ink. The black ink alone may be used for performing monochrome printing. Though not shown, the printhead  120  is provided with ink flow passages and drive devices for causing the respective ink to discharge through selected ones of the nozzle ports while the printhead  120  moves in a primary scanning direction, as indicated by a double-headed arrow X. The printing section  12  functions to print received images in a normal writing region NWR of a recording sheet RS while also printing an ink supply mark M at a trailing edge of the recording sheet RS outside the normal writing region NWR. The ink supply mark M is utilized for determining whether an ink clog or ink exhaustion has occurred. Assuming now that he printing section  12  performs only monochrome printing with he use of the black ink alone, the ink supply mark M is also printed in black in the form of a small circular dot. 
     As also shown in FIG. 2, the printhead  120  is provided with a cleaner CL for cleaning an ink flow path extending from each ink cartridge  121  to a respective one of the nozzles  120   a . A cleaning operation by the cleaner CL may be performed after replacement of an ink cartridge for example, as described hereinafter. 
     The printing section  12  is provided with a mark sensor  15  for detecting the ink supply mark M. The mark sensor  15  may be a reflection-type photoelectric tube. The mark sensor  15  may be also utilized for detecting incidence of disturbing light from outside. 
     The operation section  13  has key switches to be operated by the user for output of operation signals, whereas the display section  14  includes an LCD or the like for providing various indications under the control of the CPU  1 . 
     The facsimile machine thus constituted operates in the following manner. 
     The control process of fax reception is determined according to different combinations of mark flag and backup flag stored in the EEPROM  6 . Each of the mark flag and the backup flag may be selectively shifted from “On” (namely, “1”) to “Off” (namely, “0”) or vice versa by operating the switches of the operation section  13 . For example, by pressing two specific key switches of the operation section  13  at the same time, the mark flag is switched from “On” to “Off” or from “Off” to “On”. Similarly, by pressing other two specific key switches at the same time, the backup flag is also switched from “On” to “Off” or from “Off” to “On ”. The method for changing the mark flag is disclosed to all users through an operation manual, whereas the method for changing the backup flag is disclosed only to those users who make a specific request. This is because backup of fax-received data is desired by most users. The mark flag and the backup flag are initially set “On”. 
     Referring now to the flow diagram in FIG. 3, the CPU  1  determines whether a call is made to the facsimile machine (Step S 1 ). Specifically, the CPU  1  monitors the NCU  2  for checking whether a call signal is input through the telephone line  21 . 
     If “Yes” in Step S, the CPU  1  controls the NCU  2  to closes the line (Step S 2 ). 
     Then, the CPU  1  determines whether the received call is a fax communication (Step S 3 ). Specifically, the CPU  1  monitors the data demodulated by the modem  4  upon reception through the telephone line  21  and the NCU  2  and determines if the fax-received data are those of a fax communication. 
     If “Yes” in Step S 3 , the CPU  1  checks whether the mark flag is “On ” (Step S 4 ). Specifically, the CPU  1  reads out the mark flag from a predetermined region of the EEPROM  6  to check if the content is “1”. The mark flag determines whether or not to print an ink supply mark. The mark flag is initially set “On ” for shipment from a factory but may be changed to “Off” by suitably operating specific keys of the operation section  13 . 
     If “Yes” in Step S 4 , the CPU  1  then checks whether the backup flag is “On” (Step S 5 ). Specifically, the CPU  1  reads out the backup flag from a predetermined region of the EEPROM  6  to check if the content is “1”. The backup flag determines whether or not to store fax-received data in the RAM  3  under a predetermined condition. The backup flag is initially set “On” but may be changed to “Off” by suitably operating the operation section  13 . However, as previously described, the method for changing the backup flag is disclosed to the user only when specifically requested. 
     If “Yes” in Step S 5 , the CPU  1  executes a first control process (Step S 6 ) and completes this process routine. The specific process of the first control process will be described later. 
     If the backup flag is “Off” (“No” in Step S 5 ), the CPU  1  executes a second control process (Step S 7 ) and completes the process routine. The specific process of the second control process will be also described later. 
     In Step S 4 , if the mark flag is “On” (“No” in Step S 4 ), the CPU  1  determines whether the backup flag is “On” (Step S 8 ). 
     If “Yes” in Step S 8 , the CPU  1  executes a third control process (Step S 9 ) and completes the process routine. The specific process of the third control process will be also described later. 
     On the other hand, if “No” in Step S 8 , the CPU  1  executes a fourth control process (Step S 10 ) and completes the process routine. The specific process of the fourth control process will be also described later. 
     In Step S 3 , if the received call is not a fax communication (“No” in Step S 3 ), voice signals are being received. Therefore, the CPU  1  executes voice processing (Step S 11 ) and completes the facsimile processing routine. The voice processing includes, for example, an automatic answering mode, wherein the codec  8  converts the pre-recorded reply message (digital voice data) from the RAM  3  into analog voice signals for transmission through the NCU  2  and the telephone line  21  while converting the received message (analog voice signals) from the NCU  2  into digital voice data for storage in the RAM  3 . The voice processing itself is well known and therefore not described here in detail. 
     If there is no call in Step S 1 , this step is repeated to wait for a call. 
     FIGS. 4 and 5 are flow diagrams illustrating the first control process in Step S 6  in FIG.  3 . 
     The first control process is started with Step S 21  wherein the CPU  1  checks entry of disturbing light from outside. Specifically, the CPU  1  monitors the detection output from the mark sensor  15  to check if the output exceeds a predetermined value under the condition where no recording paper sheet is present at the detecting position of the mark sensor  15  and the light source (e.g. light emitting diode) of the mark sensor  15  is turned off. 
     If “No” in Step S 21 , the CPU  1  then determines whether the count of a dot counter is no higher than a predetermined value (Step S 22 ). Specifically, the CPU  1  reads out the count of a black-ink dot counter from the EEPROM  6  and checks if the count is no higher than a second threshold which is set higher than a first threshold. The dot counter may be provided by the CPU  1  which monitors the printing data to be supplied to the printing section  1  for calculating the accumulated count of ink dots with respect to each color, and stores the accumulated count in the EEPROM  6 . The dot counter is automatically reset for each color every time an ink cartridge is replaced. When the count of the dot counter exceeds the first threshold value, the CPU  1  causes the display section  14  to make a warning that the relevant ink (the black ink in the present embodiment) is running short. Moreover, when the count of the dot counter exceeds the second threshold, the CPU  1  causes the display section  14  to display another warning that the black ink has run out while inhibiting subsequent printing with the black ink. 
     If the count of the dot counter is no more than the predetermined value (“Yes” in Step S 22 ), the CPU  1  causes the printing section  12  to print the fax-received data (Step S 23 ). Specifically, the CPU  1  supplies the fax-received data demodulated by the modem  4  and decoded by the codec  8  to the printing section  12  through the gate array  7  for printing one band of the received image on the recording sheet RS with the black ink. One band represents the secondary scanning direction width of the image formed by one movement of the printhead  120  in the primary scanning direction. 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 24 ). 
     If “Yes” in Step S 24 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 25 ). 
     Then, the CPU  1  causes the mark sensor  15  to read the ink supply mark M (Step S 26 ). Specifically, when the ink supply mark M on the recording sheet RS reaches the detection position of the mark sensor  15 , the CPU  1  checks the detection data input from the mark sensor  15  through the gate array  7 . 
     Then, the CPU  1  determines whether the ink supply mark M is normal (Step S 27 ). Specifically, the CPU  1  checks if the value of the input detection data read in Step S 26  is less than a predetermined value. 
     If “Yes” in Step S 27 , the CPU  1  determines whether all pages of fax-received data have been printed (Step S 28 ). 
     If “No” in Step S 28  (i.e., if there are more pages of fax-received data), the CPU  1  checks whether there is disturbing light entry from outside (Step S 29 ). 
     If “Yes” in Step S 29 , the CPU  1  checks whether the RAM  3  is full (Step S 30 ). Specifically, the CPU  1  checks whether the non-occupied capacity of the RAM  3  is no less than a predetermined amount. 
     If “No” in Step S 30 , the CPU  1  stores the fax-received data in the RAM  3  as backup data (Step S 32 ). Specifically, the CPU  1  causes the DMAC  9  to store predetermined bytes of fax-received data in the RAM  3  each time. In other words, upon entry of disturbing light during fax reception, the CPU  1  stops printing out the fax-received data on the relevant page and shifts to memory reception. At this time, the RAM  3  also stores, together with the backup data, various secondary data which include fax reception time, fax sender, and information indicating that the fax-received data have not been already printed out. Further, after subsequently printing out the backup data, the “non-printed” indication in the RAM  3  is changed to a “printed” indication. 
     Then, the CPU  1  determines whether one page of fax-received data has been stored in the RAM  3  (Step S 33 ). 
     If “Yes” in Step S 33 , the CPU  1  then determines whether all pages of fax-received data have been stored in the RAM  3  (Step S 34 ). 
     If “Yes” in Step S 34 , the CPU  1  causes the NCU  2  to open the telephone line  21  (FIG. 5; Step S 35 ). 
     Then, in Step S 36 , the CPU  1  determines whether the count of the dot counter is no higher than the predetermined value (i.e., the second threshold as previously defined). 
     If the count of the dot counter is no more than the second threshold (“Yes” in Step S 36 ), the CPU  1  causes the printing section  12  to print out the backup data (Step S 37 ). Specifically, the CPU  1  reads out the backup data from the RAM  3  (previously stored in Step S 32 ) and supplies them to the printing section  12  through the gate array  7  for printing one band of the backup data on the recording sheet RS with the black ink. 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 38 ). 
     If “Yes” in Step S 38 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 39 ). 
     Then, the CPU  1  causes the mark sensor  15  to read the ink supply mark M (Step S 40 ). 
     Then, the CPU  1  determines whether the ink supply mark M is normal (Step S 41 ). 
     If “No” in Step S 41 , the CPU  1  sets a flag A to “1” (Step S 42 ). Specifically, the CPU  1  reads out the flag A from a predetermined region of the EEPROM  6  and rewrite the value “0” to “1” if it is currently “0” while maintaining the same value if it is currently “1”. The flag A indicates whether the ink supply mark M read during the printing of the backup data is normal or not. The value “1” of the flag A represents that the ink supply mark M is not normal, whereas the value “0” of the flag A means that the ink supply mark M is normal. 
     Then, the CPU  1  determines whether all pages of backup data have been printed (Step S 43 ). 
     If “Yes” in Step S 43 , the CPU  1  determines whether the flag A is currently “0” (Step S 44 ). If “No” in Step S 44 , it is suspected that the backup data may not have been normally printed. Therefore, the CPU  1  rewrites the flag A to “0” (Step S 45 ) and terminates the first control process routine without erasing the backup data in the RAM  3 . 
     In Step S 44 , if the flag A is “0” (“Yes” in Step S 44 ), it estimated that all pages of backup data have been normally printed because the ink supply mark M for every page has been normally read. Therefore, the CPU  1  erases the backup data currently stored in the RAM  3  (Step S 46 ) and terminates the first control process routine. 
     In Step S 43 , if all pages of backup data have not been printed out (“No” in Step S 43 ), Step S 36  follows to prepare for printing a new page of backup data. 
     In Step S 41 , if the ink supply mark M has been normally read (“Yes” in Step S 41 ), the process proceeds to Step S 43  by skipping Step S 42  because it is unnecessary to set the flag A to “1”. 
     In Step S 38 , if the printing of one page of backup data has not finished yet (“No” in Step S 38 ), the printing of the same page is continued by returning to Step S 37 . 
     In Step S 36 , if the count of the dot counter is more than the second threshold (“No” in Step S 36 ), the CPU  1  causes the display section  14  to make an ink run-out indication (Step S 47 ). 
     Step S 47  is followed by Step S 48  wherein the CPU  1  sets a printing inhibition mode before proceeding to Step S 45 . When the printing inhibition mode is set, memory reception (i.e., reception of the fax data by the RAM  3 ) prevails over real-time printing, and the CPU  1  refuses fax reception unless the usable capacity of the RAM  3  exceeds a predetermined amount. The printing inhibition mode is canceled when the black ink flow path is automatically cleaned by the cleaner CL (FIG. 2) after ink cartridge replacement. 
     In Step S 34  (see FIG.  4 ), unless all pages of fax-received data have been stored in the RAM  3  (“No” in Step S 34 ), Step S 30  follows to prepare for storing a new page of fax-received data. 
     In Step S 33 , unless one page of fax-received data have been stored in the RAM  3  (“No” in Step S 33 ), the data storage for the same page is continued by returning to Step S 32 . 
     In Step S 30 , if the RAM  3  is found full (“Yes” in Step S 30 ), the first control process proceeds to Step S 35  (see FIG. 5) by skipping Steps S 32 -S 34  because no memory region is available for data backup. 
     In Step S 29 , if there is disturbing light (“No” in Step S 29 ), Step S 22  follows to prepare for subsequent printing. 
     In Step S 28 , if the printing of the fax-received data is completed over all pages (“Yes” in Step S 28 ), the CPU  1  opens the telephone line  21  (Step S 49 ). 
     Then, the CPU  1  wholly erases those of the stored backup data (Step S 50 ) which have been already printed out, and terminates the first control process routine. Specifically, the CPU  1  reads the secondary data attendant with each set of backup data from the RAM  3 , determines whether the set of backup data is already printed or not, and erases the printed set of backup data from the RAM  3 . 
     In Step S 27 , if the ink supply mark M is not normally read despite the absence of disturbing light entry (“No” in Step S 27 ), an ink clog must have occurred. Therefore, the CPU  1  executes an ink clog process (Step S 51 ) and terminates the first control process routine. The details of the ink clog process will be described hereinafter. 
     In Step S 24 , if the printing of one page of fax-received data has not finished yet (“No” in Step S 24 ), the printing of the same page is continued by returning to Step S 23 . 
     In Step S 22 , if the count of the dot counter is more than the second threshold (“No” in Step S 22 ), the CPU  1  performs an ink run-out process (Step S 52 ) because the black ink must have run out, and terminates the first control process routine. The details of the ink run-out process will described hereinafter. 
     In Step S 21 , if there is disturbing light (“Yes” in Step S 21 ), the CPU  1  determines whether the RAM  3  is full (Step S 53 ). 
     If “No” in Step S 53 , the CPU  1  determines whether the count of the dot counter is no higher than the second threshold (Step S 55 ). 
     If “Yes” in Step S 55 , the CPU  1  causes the printing section  12  to print out the fax-received data while also storing the same data in the RAM (Step S 56 ). Specifically, the CPU  1  supplies the fax-received data (as demodulated by the modem  4  and as decoded by the codec  8 ) to the printing section  12  through the gate array  7  for printing on the recording sheet RS with the black ink while also causing the DMAC  9  to store predetermined bytes of fax-received data in the RAM  3  each time. 
     Then, the CPU  1  determines whether the printing and storing of one page data is completed (Step S 57 ). 
     If “Yes” in Step S 57 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 58 ). 
     Then, the CPU  1  determines whether all pages of fax-received data have been printed and stored (Step S 59 ). 
     If “Yes” in Step S 59 , the CPU  1  opens the telephone line  21  (Step S 60 ). 
     Then, the CPU  1  performs an inquiry process for inquiring about the printing results (Step S 61 ) and terminates the first control process routine. The details of the result inquiry process will be described hereinafter. 
     In Step S 59 , if the printing and storing of the fax-received data has not been completed over all pages (“No” in Step S 59 ), Step S 53  follows to prepare for subsequently printing and storing a new page of fax-received data. 
     In Step S 57 , if the printing and storing of one page of fax-received data has not finished yet (“No” in Step S 57 ), the printing and storing of the same page is continued by returning to Step S 56 . 
     In Step S 55 , if the count of the dot counter is more than the second threshold (“No” in Step S 55 ), the CPU  1  performs an ink run-out process (Step S 62 ) because the black ink must have run out, and terminates the first control process routine. The details of the ink run-out process will described hereinafter. 
     In Step S 53 , if the RAM  3  is full (“Yes” in Step S 53 ), the CPU  1  determines whether there are any batches of printed backup data in the RAM  3  (Step S 63 ). 
     If “Yes” in Step S 63 , one batch of printed backup data in the RAM  3  is erased in Step S 64  which is followed by Step S 53  in a loop. 
     If “No” in Step S 63 , the CPU  1  controls the NCU  2  to open the telephone line  21  line (Step S 65 ) and terminates the first control process routine. 
     In this way, when both of the mark flag and the backup flag are “On ” in the absence of disturbing light, the printing section  12  prints out fax-received data in real time while also printing an ink supply mark M which is detected by the mark sensor  15 . If the ink supply mark M can be normally read with respect to every page, it is estimated that no ink clog has occurred. Therefore, those of the backup data in the RAM  3 , if already printed out, are entirely erased. 
     If the ink supply mark cannot be normally read even though there is no disturbing light, it is considered that an ink clog has occurred, so that memory reception of the fax data ensues. 
     If disturbing light enters in the course of real-time printing, memory reception of the fax data takes the place of the real-time printing, and the memory backup data are automatically printed out immediately upon completion of the memory reception. Such a control is adopted because disturbing light incoming in the course of real-time printing is considered temporary and will be no longer present when the memory reception finishes. 
     If disturbing light is present at the very start of fax reception, memory backup of the fax-received data starts with the first page while simultaneously performing real-time printing. This is because an ink supply mark M may not be normally read in the presence of disturbing light. 
     FIG. 6 is a flow diagram illustrating the second control process (Step S 7  in FIG. 3) which is adopted when the mark flag is “On” with the backup flag shifted to “Off”. 
     The second control process starts with Step S 71  wherein the CPU  1  checks the presence of disturbing light from outside. 
     If “No” in Step S 71 , the CPU  1  then determines whether the count of the dot counter is no higher than the second threshold (Step S 72 ). 
     If the count of the dot counter is no more than the predetermined value (“Yes” in Step S 72 ), the CPU  1  causes the printing section  12  to print the fax-received data (Step S 73 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 74 ). 
     If “Yes” inStep S 74 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 75 ). 
     Then, the CPU  1  causes the mark sensor  15  to read the ink supply mark M (Step S 76 ). 
     Then, the CPU  1  determines whether the ink supply mark M is normal (Step S 77 ). 
     If “Yes” in Step S 77 , the CPU  1  determines whether all pages of fax-received data have been printed (Step S 78 ). 
     If “Yes” in Step S 78 , the CPU  1  causes the NCU  2  to open the telephone line  21  (Step S 79 ) and terminates the second control process routine. 
     In Step S 78 , if all pages of fax-received data have not been printed yet (“No” in Step S 78 ), Step S 71  follows in a loop to prepare for printing a new page of fax-received data. 
     In Step S 77 , if the ink supply mark M is not normally read despite the absence of disturbing light entry (“No” in Step S 77 ), an ink clog must have occurred. Therefore, the CPU  1  executes an ink clog process (Step S 80 ) and terminates the second control process routine. The details of the ink clog process will be described hereinafter. 
     In Step S 74 , if the printing of one page of fax-received data has not finished yet (“No” in Step S 74 ), the printing of the same page is continued by returning to Step S 73 . 
     In Step S 72 , if the count of the dot counter is more than the second threshold (“No” in Step S 72 ), the CPU  1  performs an ink run-out process (Step S 81 ), and terminates the second control process routine. The details of the ink run-out process will described hereinafter. 
     In Step S 71 , if there is disturbing light (“Yes” in Step S 71 ), the CPU  1  determines whether the count of the dot counter is no higher than the second threshold (Step S 82 ). 
     If “Yes” in Step S 82 , the CPU  1  causes the printing section  12  to print out the fax-received data (Step S 83 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 84 ). 
     If “Yes” in Step S 84 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 85 ). 
     Then, the CPU  1  determines whether all pages of fax-received data have been printed (Step S 86 ). 
     If “Yes” in Step S 86 , the CPU  1  opens the telephone line  21  (Step S 79 ) and terminates the second control process routine. 
     In Step S 86 , if the printing of the fax-received data has not been completed over all pages (“No” in Step S 86 ), Step S 82  follows to prepare for subsequently printing a new page of fax-received data. 
     In Step S 84 , if the printing of one page of fax-received data has not finished yet (“No” in Step S 84 ), the printing of the same page is continued by returning to Step S 83 . 
     In Step S 82 , if the count of the dot counter is more than the second threshold (“No” in Step S 82 ), the CPU  1  performs an ink run-out process (Step S 87 ) and terminates the second control process routine. The details of the ink run-out process will described hereinafter. 
     In this way, when the mark flag is “On” with the backup flag shifted to “Off”, the CPU  1  causes the printing section  12  to print out fax-received data without causing the RAM  3  to store the same data for backup regardless of the presence or absence of disturbing light. Such a control takes account of the intention of the user who has chosen not to keep the fax-received data as memory backup data. It is only in the ink run-out process or the ink clog process (to be described later) that the RAM  3  stores fax-received data for backup. 
     FIG. 7 is a flow diagram illustrating the third control process (Step S 9  in FIG. 3) which is performed when the mark flag is “Off” with the backup flag held “On”. 
     The third control process starts with Step S 91  wherein the CPU  1  determines whether the RAM  3  is full. 
     If “No” in Step S 91 , the CPU I determines whether the count of the dot counter is no higher than the second threshold (Step S 93 ). 
     If “Yes” in Step S 93 , the CPU  1  causes the printing section  12  to print out the fax-received data while also storing the same data in the RAM (Step S 94 ). 
     Then, the CPU  1  determines whether the printing and storing of one page data is completed (Step S 95 ). 
     If “Yes” in Step S 95 , the CPU  1  determines whether all pages of fax-received data have been printed and stored (Step S 96 ). 
     If “Yes” in Step S 96 , the CPU  1  opens the telephone line  21  (Step S 97 ). 
     Then, the CPU  1  performs an inquiry process for inquiring about the printing results (Step S 98 ) and terminates the third control process routine. The details of the result inquiry process will be described hereinafter. 
     In Step S 96 , if the printing and storing of the fax-received data has not been completed over all pages (“No” in Step S 96 ), Step S 91  follows to prepare for subsequently printing and storing a new page of fax-received data. 
     In Step S 95 , if the printing and storing of one page of fax-received data has not finished yet (“No” in Step S 95 ), the printing and storing of the same page is continued by returning to Step S 94 . 
     In Step S 93 , if the count of the dot counter is more than the second threshold (“No” in Step S 93 ), the CPU  1  performs an ink run-out process (Step S 62 ) and terminates the third control process routine. The details of the ink run-out process will described hereinafter. 
     In Step S 91 , if the RAM  3  is full (“Yes” in Step S 91 ), the CPU  1  determines whether there are any batches of printed backup data in the RAM  3  (Step S 92   a ). 
     If “No” in Step S 92   a , the CPU  1  controls the NCU  2  to open the telephone line  21  line (Step S 92   b ) and terminates the third control process routine. 
     If “Yes” in Step S 92   a , one batch of printed backup data in the RAM  3  is erased in Step S 92   c  which is followed by Step S 91  in a loop. 
     In this way, when the mark flag is “Off” with the backup flag held “On”,the CPU  1  causes the RAM  3  to store all fax-received data for backup regardless of the presence or absence of disturbing light. Further, the printing section  12  does not print any ink supply mark on any recording paper sheet. 
     FIG. 8 is a flow diagram illustrating the fourth control process (Step S 10  in FIG. 3) which is performed when both of the mark flag and the backup flag are “Off”. 
     The fourth control process starts with Step S 101  wherein the CPU  1  determines whether the count of the dot counter is no higher than the second threshold. 
     If “Yes” in Step S 101 , the CPU  1  causes the printing section  12  to print out the fax-received data (Step S 102 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 103 ). 
     If “Yes” in Step S 103 , the CPU  1  determines whether all pages of fax-received data have been printed (Step S 104 ). 
     If “Yes” in Step S 104 , the CPU  1  opens the telephone line  21  (Step S 105 ) and terminates the fourth control process routine. 
     In Step S 104 , if the printing of the fax-received data has not been completed over all pages (“No” in Step S 104 ), Step S 101  follows to prepare for subsequently printing a new page of fax-received data. 
     In Step S 103 , if the printing of one page of fax-received data has not finished yet (“No” in Step S 103 ), the printing of the same page is continued by returning to Step S 102 . 
     In Step S 101 , if the count of the dot counter is more than the second threshold (“No” in Step S 101 ), the CPU  1  performs an ink run-out process (Step S 106 ) and terminates the fourth control process routine. The details of the ink run-out rocess will described hereinafter. 
     In this way, when both of the mark flag and the backup flag are “Off”, no printing of an ink supply mark and no data backup take place regardless of the presence or absence of disturbing light. 
     FIG. 9 is a flow diagram illustrating the result inquiry process (Step S 61  in FIG. 4; Step S 98  in FIG.  7 ). 
     The result inquiry process begins with Step Sill wherein the CPU  1  causes the display section  14  to display inquiries to the user about the print results. Specifically, the CPU  1  causes the display section  14  to alternately display two different inquiry indications at a predetermined interval, as shown in FIGS. 10A and 10B. 
     Then, the CPU  1  determines whether the user has entered a print-OK signal (Step S 112 ). Specifically, the CPU  1  checks whether the user has pressed the No.1 key of the numeral keys at the operation section  13 . 
     If “No” in Step S 112 , the CPU  1  determines whether the user has entered a print-NG signal (NG: No Good) (S 113 ). Specifically, the CPU  1  checks whether the user has pressed the No.2 key of the numeral keys at the operation section  13 . 
     If “Yes” in Step S 113 , the CPU  1  causes the display section  14  to delete the inquiry indications (Step S 114 ) and terminates the result inquiry process routine. 
     If “No” in Step S 113 , Step S 112  follows in a loop to wait for a user&#39;s input operation. 
     In Step S 112 , if the user makes a print-OK input (“Yes” in Step S 112 ), the CPU  1  erases the relevant backup data (Step S 115 ) and proceeds to Step S 114 . Specifically, the CPU  1  erases the fax-received data stored in the RAM  3  in Step S 56  (FIG. 4) or Step S 94  (FIG.  7 ). 
     In this way, when printing and storing are simultaneously performed, inquiry is made to the user as to the print results. If the print results are acceptable, the relevant batch of backup data is erased so that unnecessary backup data will not remain in the RAM  3 . 
     FIG. 11 is a flow diagram illustrating the ink clog process in Step S 51  in FIG. 4 or Step S 80  in FIG.  6 . 
     The ink clog process starts with Step S 121  wherein the CPU  1  checks whether the RAM  3  is full. 
     If “No” in Step S 121 , the CPU  1  stores the fax-received data in the RAM  3  as backup data (Step S 123 ). Specifically, the CPU  1  first transfers, from the buffer region of the RAM  3  to the backup region of the same, a batch of fax-received data corresponding to the page whose ink supply mark has not been properly read by the mark sensor  15 , and then causes the DMAC  9  to store subsequent batches of fax-received data (corresponding to the subsequent pages) in the RAM  3 . Even the printed batch of fax-received is stored in the RAM  3  for backup because a failure to normally read the ink supply mark of a particular page represents the likelihood that an ink clog should have occurred in the course of printing that page. 
     Then, the CPU  1  determines whether one page of fax-received data has been stored in the RAM  3  (Step S 124 ). 
     If “Yes” in Step S 124 , the CPU  1  then determines whether all pages of fax-received data have been stored in the RAM  3  (Step S 125 ). 
     If “Yes” in Step S 125 , the CPU  1  causes the NCU  2  to open the telephone line  21  (Step S 126 ). 
     Then, the CPU  1  controls the display section  14  to make an ink clog indication (Step S 127 ). 
     Then, the CPU  1  sets a printing inhibition mode (Step S 128 ) and terminates the ink clog process routine. Once the printing inhibition mode is set, memory fax reception prevails, and the CPU  1  refuses fax reception unless the usable capacity of the RAM  3  exceeds a predetermined amount. The printing inhibition mode is canceled only after the cleaning of the black ink flow path which is performed in response to the user&#39;s pressing of a predetermined key at the operation section  13  or automatically at a predetermined time interval while the facsimile machine is turned on. 
     In Step S 125 , unless all pages of fax-received data have been stored in the RAM  3  (“No” in Step S 125 ), Step S 121  follows in a loop to prepare for storing a new page of fax-received data. 
     In Step S 124 , unless one page of fax-received data have been stored in the RAM  3  (“No” in Step S 124 ), the data storage for the same page is continued by returning to Step S 123 . 
     In Step S 121 , if the RAM  3  is found full (“Yes” in Step S 121 ), the ink clog process proceeds to Step S 126  by skipping Steps S 123 -S 125  because no memory region is available for data backup. 
     In this way, when an ink supply mark cannot be normally read, it is presumed that the black ink flow path has been clogged, so that an ink clog indication is displayed so as to prompt the user for cleaning the black ink flow path. 
     FIG. 12 is a flow diagram illustrating the ink run-out process (Step S 52  in FIG. 4; Steps S 81  and S 87  in FIG. 6; Step S 99  in FIG. 7; Step  106  in FIG.  8 ). 
     The ink run-out process starts with Step S 131  wherein the CPU  1  checks whether the RAM  3  is full. 
     If “No” in Step S 131 , the CPU  1  stores the fax-received data in the RAM  3  as backup data (Step S 133 ). Specifically, the CPU  1  causes the DMAC  9  to store predetermined bytes of fax-received data in the RAM  3  each time. At this time, since the second threshold of the dot counter is set slightly lower than an actual ink run-out value for enabling the completion of printing the relevant page, backup of the fax-received data by the RAM  3  starts with the next page. 
     Then, the CPU  1  determines whether one page of fax-received data has been stored in the RAM  3  (Step S 134 ). 
     If “Yes” in Step S 134 , the CPU  1  then determines whether all pages of fax-received data have been stored in the RAM  3  (Step S 135 ). 
     If “Yes” in Step S 135 , the CPU  1  causes the NCU  2  to open the telephone line  21  (Step S 136 ). 
     Then, the CPU  1  controls the display section  14  to make an ink run-out indication (Step S 137 ). 
     Then, the CPU  1  sets a printing inhibition mode (Step S 138 ) and terminates the ink run-out process routine. Once the printing inhibition mode is set, memory fax reception prevails, and the CPU  1  refuses fax reception unless the usable capacity of the RAM  3  exceeds a predetermined amount. The printing inhibition mode is canceled only after the cleaning of the black ink flow path which is performed after replacement of a black ink cartridge. 
     In Step S 135 , unless all pages of fax-received data have been stored in the RAM  3  (“No” in Step S 135 ), Step S 131  follows in a loop to prepare for storing a new page of fax-received data. 
     In Step S 134 , unless one page of fax-received data have been stored in the RAM  3  (“No” in Step S 134 ), the data storage for the same page is continued by returning to Step S 133 . 
     In Step S 131 , if the RAM  3  is found full (“Yes” in Step S 131 ), the CPU  1  determines whether there are any batches of printed backup data in the RAM  3  (Step S 139 ). 
     If “Yes” in Step S 139 , one batch of printed backup data in the RAM  3  is erased in Step S 140  which is followed by Step S 131  in a loop. 
     If “No” in Step S 139 , the ink run-out process proceeds to Step S 136  which is previously described. 
     In this way, when the count of the black ink dot counter exceeds the second threshold, the CPU  1  detects an ink run-out and prompts the user to replace the black in cartridge. 
     FIG. 13 is a flow diagram a post-cleaning process which is automatically performed after the cleaning of the black ink flow path in response to the user&#39;s pressing of a predetermined key at the operation section  13 , or at a predetermined time interval while the facsimile machine is turned on, or after replacement of a black ink cartridge. 
     The post-cleaning process begins with Step S 141  wherein the CPU  1  checks whether a printing inhibition mode is set. 
     If “Yes” in Step S 141 , the CPU  1  cancels the printing inhibition mode (S 142 ). 
     Then, the CPU  1  determines whether the mark flag is “On” (Step  143 ). Specifically, the CPU  1  reads out the mark flag from the EEPROM  6  to check whether it is currently “1”. 
     If “Yes” in Step S 143 , the CPU  1  checks entry of disturbing light from outside (Step S 144 ). Specifically, the CPU  1  monitors the detection output from the mark sensor  15  to check if the output exceeds a predetermined value under the condition where no recording paper sheet is present at the detecting position of the mark sensor  15  and the light source (e.g. light emitting diode) of the mark sensor  15  is turned off. 
     If “No” in Step S 144 , the CPU  1  then determines whether the count of the dot counter is no higher than the second threshold (Step S 145 ). 
     If “Yes” in Step S 145 , the CPU  1  reads out the backup data from the RAM  3  and supplies them to the printing section  12  through the gate array  7  for printing out (Step S 146 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 147 ). 
     If “Yes” in Step S 147 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 148 ). 
     Then, the CPU  1  causes the mark sensor  15  to read the ink supply mark M (Step S 149 ). 
     Then, the CPU  1  determines whether the ink supply mark M has been normally read by the mark sensor  15  (Step S 150 ). 
     If “No” in Step S 150 , the CPU  1  sets a flag B to “1” (Step S 151 ). Specifically, the CPU  1  reads out the flag B from a predetermined region of the EEPROM  6  and rewrite the value “0” to “1” if it is currently “0” while maintaining the same value if it is currently “1”. The flag B indicates whether the ink supply mark M read during the printing of the backup data is normal or not. The value “1” of the flag B represents that the ink supply mark M is not normal, whereas the value “0” of the flag B means that the ink supply mark M is normal. 
     Then, the CPU  1  determines whether all pages of backup data for one batch or case have been printed (Step S 152 ). 
     If “Yes” in Step S 152 , the CPU  1  checks whether all batches or cases of backup data have been printed (Step S 153 ). 
     If “Yes” in Step S 153 , the CPU  1  determines whether the flag B is currently “0” (Step S 154 ). 
     If “Yes” in Step S 154 , it estimated that all batches of backup data have been normally printed because the ink supply mark M for every page has been normally read with respect to every batch of the backup data. Therefore, the CPU  1  erases all of the backup data currently stored in the RAM  3  (Step S 155 ) and terminates the post-cleaning process routine. 
     If “No” in Step S 155 , on the other hand, it is suspected hat the backup data may not have been normally printed. Therefore, the CPU  1  causes the display section  14  to display inquiries to the user about the print results (Step S 156 ). Specifically, the CPU  1  causes the display section  14  to alternately display the two different inquiry indications (see FIGS. 10A and 10B) at a predetermined interval, similarly to the result inquiry process illustrated in FIG.  9 . 
     Then, the CPU  1  determines whether the user has entered a print-OK signal (Step S 157 ). Specifically, the CPU  1  checks whether the user has pressed the No.1 key of the numeral keys at the operation section  13 . 
     If “No” in Step S 157 , the CPU  1  determines whether the user has entered a print-NG signal (Step S 158 ). Specifically, the CPU  1  checks whether the user has pressed the No.2 key of the numeral keys at the operation section  13 . 
     If “Yes” in Step S 158 , the CPU  1  causes the display section  14  to delete the inquiry indications (Step S 114 ). 
     Then, the CPU  1  sets the flag B to “Off” and terminates the post-cleaning process routine. 
     If “No” in Step S 158 , Step S 157  follows in a loop to wait for a user&#39;s input operation. In Step S 157 , if the user makes a print-OK input (“Yes” in Step S 157 ), the CPU  1  controls the display section  14  to delete the inquiry indications (Step S 161 ) and then sets the flag B to “Off” before proceeding to Step S 155 . 
     In Step S 153 , if all batches or cases of backup data have not been printed out (“No” in Step S 153 ), Step S 144  follows in a loop to prepare for printing the next batch of backup data. 
     In Step S 152 , if all pages of backup data have not been printed out (“No” in Step S 152 ), Step S 144  follows again to prepare for printing a new page of backup data. 
     In Step S 150 , if the ink supply mark M has been normally read (“Yes” in Step S 150 ), the process proceeds to Step S 152  by skipping Step S 151  because it is unnecessary to set the flag B to “1”. 
     In Step S 147 , if the printing of one page of backup data has not finished yet (“No” in Step S 147 ), the printing of the same page is continued by returning to Step S 146 . 
     In Step S 145 , if the count of the dot counter is more than the second threshold (“No” in Step S 145 ), the CPU  1  causes the display section  14  to make an ink run-out indication (Step S 163 ). 
     Step S 163  is followed by Step S 164  wherein the CPU  1  sets a printing inhibition mode. 
     Then, the CPU  1  sets the flag B to “0” (Step S 151 ) and terminates the post-cleaning process routine. Specifically, the CPU  1  reads out the flag B from the EEPROM  6  and rewrite the value “1” to “0” if it is currently “1” while maintaining the same value if it is currently “0”. 
     In Step S 144 , if there is disturbing light (“Yes” in Step S 144 ), the CPU  1  set the flag B to “1” (Step S 165 ). 
     Then, the CPU  1  determines whether the count of the dot counter is no higher than the second threshold (Step S 166 ). 
     If “Yes” in Step S 166 , the CPU  1  reads out the backup data from the RAM  3  and supplies them to the printing section  12  through the gate array  7  for printing out (Step S 167 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 168 ). 
     If “Yes” in Step S 168 , the CPU  1  determines whether all pages of backup data for one batch or case have been printed (Step S 169 ). 
     If “Yes” in Step S 169 , the CPU  1  checks whether all batches or cases of backup data have been printed (Step S 170 ). 
     If “Yes” in Step S 170 , the post-cleaning process proceeds to Step S 153  to prepare for subsequent erasion of the backup data. 
     In Step S 170 , if all batches or cases of backup data have not been printed out (“No” in Step S 170 ), Step S 166  follows in a loop to prepare for printing the next batch of backup data. 
     In Step S 169 , if all pages of backup data have not been printed out (“No” in Step S 169 ), Step S 166  follows again to prepare for printing a new page of backup data. 
     In Step S 168 , if the printing of one page of backup data has not finished yet (“No” in Step S 168 ), the printing of the same page is continued by returning to Step S 167 . 
     In Step S 166 , if the count of the dot counter is more than the second threshold (“No” in Step S 166 ), the post-cleaning process proceeds to Step S 163 . 
     In Step S 143 , if the mark flag is not “On” (“No” in Step S 143 ), the CPU  1  terminates the post-cleaning process routine because it is impossible to check whether the printing is proper even if the backup data are automatically printed out. 
     In Step S 141 , if the printing inhibition mode is not set (“No” in Step S 141 ), the post-cleaning process proceeds to Step S 143  by skipping Step S 142  because there is no need to cancel the printing inhibition mode. 
     In this way, when the mark flag is “On”,the backup data stored in the RAM  3  are automatically printed out after cleaning the black ink flow path. Further, if the ink supply mark is normally read with respect to all pages of all batches or cases, all of the backup data are automatically erased. However, if there is any ink supply mark which cannot be normally read, an inquiry is made to the user as to whether the backup data may be deleted. 
     FIG. 14 is a flow diagram illustrating a process for manual deletion or erasion of the backup data which is carried out in response to a predetermined key operation by the user. Such manual deletion of the backup data is necessary when successively performing full-color copying which requires a large region of the RAM  3 . Further, the manual deletion process may also be utilized when the user wishes to print out the backup data on recording paper sheets. 
     The manual deletion process starts with Step S 181  wherein the CPU  1  determines whether any backup data remain in the RAM  3 . Examples of backup data here include all kinds of fax-received data stored in the RAM  3  for any reason (not only at the time of an ink clog or an ink run-out, but also at the time of a paper jam, a paper run-out or a data transfer). 
     If “Yes” in Step S 181 , the CPU  1  causes the display section  14  to display inquiries to the user as to the need for printing out the remaining backup data (Step S 182 ). Specifically, the CPU  1  causes the display section  14  to alternately display two different inquiry indications at a predetermined interval, as shown FIGS. 15A and 15B. 
     Then, the CPU  1  determines whether the user has entered a non-print signal (Step S 183 ). Specifically, the CPU  1  checks whether the user has pressed the No.2 key of the numeral keys at the operation section  13 . 
     If “No” in Step S 183 , the CPU  1  determines whether the user has requested a print-out of the remaining backup data (Step S 184 ). Specifically, the CPU  1  checks whether the user has pressed the No.1 key of the numeral keys at the operation section  13 . 
     At the time of carrying out Steps S 183  and S 184 , the user may refer to a memory status list which may be printed out or displayed at the display section  14  in response to a predetermined key operation of the user at the operation section  13 . The memory status list may contain various pieces of information (such as the sender&#39;s name, the sender&#39;s telephone number and the time of fax reception) which may be useful for the user in determining the need for printing out the backup data. Further, the user may also refer to an communication activity report (see FIG. 16) which may be printed out at any time by a predetermined key operation of the user or automatically at a predetermined time interval. 
     If “Yes” in Step S 184 , the CPU  1  causes the display section  14  to make a print-busy indication (Step S 185 ), as shown in FIG.  17 . 
     Then, the CPU  1  determines whether the mark flag is “On” (Step  186 ). Specifically, the CPU  1  reads out the mark flag from the EEPROM  6  to check whether it is currently “1”. 
     If “Yes” in Step S 186 , the CPU  1  checks entry of disturbing light from outside (Step S 187 ). Specifically, the CPU  1  monitors the detection output from the mark sensor  15  to check if the output exceeds a predetermined value under the condition where no recording paper sheet is present at the detecting position of the mark sensor  15  and the light source of the mark sensor  15  is turned off. 
     If “No” in Step S 187 , the CPU  1  then determines whether the count of the dot counter is no higher than the second threshold (Step S 188 ). 
     If “Yes” in Step S 188 , the CPU  1  reads out the backup data from the RAM  3  and supplies them to the printing section  12  through the gate array  7  for printing out (Step S 189 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 190 ). 
     If “Yes” in Step S 190 , the CPU  1  controls the printing section  12  to print an ink supply mark M at the trailing edge of the recording sheet RS (Step S 191 ). 
     Then, the CPU  1  causes the mark sensor  15  to read the ink supply mark M (Step S 192 ). 
     Then, the CPU  1  determines whether the ink supply mark M has been normally read by the mark sensor  15  (Step S 193 ). 
     If “No” in Step S 193 , the CPU  1  sets a flag C to “1” (Step S 194 ). Specifically, the CPU  1  reads out the flag C from the EEPROM  6  and rewrite the value “0” to “1” if it is currently “0” while maintaining the same value if it is currently “1”. The flag C indicates whether the ink supply mark M read during the printing of the backup data is normal or not. The value “1” of the flag C represents that the ink supply mark M is not normal, whereas the value “0” of the flag C means that the ink supply mark M is normal. 
     Then, the CPU  1  determines whether all pages of backup data for one batch or case have been printed (Step S 195 ). 
     If “Yes” in Step S 195 , the CPU  1  checks whether all batches or cases of backup data have been printed (Step S 196 ). 
     If “Yes” in Step S 196 , the CPU  1  determines whether the flag C is currently “0” (Step S 197 ). 
     If “Yes” in Step S 197 , it estimated that all batches of backup data have been normally printed because the ink supply mark M for every page has been normally read with respect to every batch of the backup data. Therefore, the CPU  1  erases all of the backup data currently stored in the RAM  3  (Step S 198 ). 
     Then, the CPU  1  controls the display section  14  to cancel the print-busy indication and the print request inquiry indications (Step S 199 ). 
     Then, the CPU  1  sets the flag C to “0” (Step S 200 ) and terminates the manual deletion process routine. Specifically, the CPU  1  reads out the flag C from the EEPROM  6  and rewrite the value “1” to “0” if it is currently “1” while maintaining the same value if it is currently “0”. 
     In Step S 197 , if the flag C is “1” (“No” in Step S 197 ), on the other hand, it is suspected that the backup data may not have been normally printed. Therefore, the CPU  1  causes the display section  14  to display inquiries to the user about the print results (Step S 201 ). Specifically, the CPU  1  causes the display section  14  to alternately display the two different inquiry indications (see FIGS. 10A and 10B) at a predetermined interval, similarly to the result inquiry process illustrated in FIG.  9 . 
     Then, the CPU  1  determines whether the user has entered a print-OK signal (Step S 202 ). Specifically, the CPU  1  checks whether the user has pressed the No.1 key of the numeral keys at the operation section  13 . 
     If “No” in Step S 202 , the CPU  1  determines whether the user has entered a print-NG signal (Step S 203 ). Specifically, the CPU  1  checks whether the user has pressed the No.2 key of the numeral keys at the operation section  13 . 
     If “Yes” in Step S 203 , the manual deletion process proceeds to Step S 199  for canceling the print-busy indication and the print request inquiry indications. 
     If “No” in Step S 203 , Step S 202  follows in a loop to wait for a user&#39;s input operation. 
     In Step S 202 , if the user makes a print-OK input (“Yes” in Step S 202 ), the manual deletion process proceeds to Step S 198  for deleting all of the backup data. 
     In Step  5196 , if all batches or cases of backup data have not been printed out (“No” in Step S 196 ), Step S 186  follows in a loop to prepare for printing the next batch of backup data. 
     In Step S 195 , if all pages of backup data have not been printed out (“No” in Step S 196 ), Step S 186  follows again to prepare for printing a new page of backup data. 
     In Step S 193 , if the ink supply mark M has been normally read (“Yes” in Step S 193 ), the manual deletion process proceeds to Step S 195  by skipping Step S 194  because it is unnecessary to set the flag C to “1”. 
     In Step S 190 , if the printing of one page of backup data has not finished yet (“No” in Step S 190 ), the printing of the same page is continued by returning to Step S 189 . 
     In Step S 188 , if the count of the dot counter is more than the second threshold (“No” in Step S 188 ), the CPU  1  causes the display section  14  to make an ink run-out indication (Step S 204 ). 
     Step S 204  is followed by Step S 205  wherein the CPU  1  sets a printing inhibition mode, which latter step is further followed by Step S 200  wherein the CPU  1  sets the flag C to “0”. 
     In Step S 187 , if there is disturbing light (“Yes” in Step S 187 ), the CPU  1  set the flag C to “1” (Step S 206 ). 
     Then, the CPU  1  determines whether the count of the dot counter is no higher than the second threshold (Step S 207 ). 
     If “Yes” in Step S 207 , the CPU  1  reads out the backup data from the RAM  3  and supplies them to the printing section  12  through the gate array  7  for printing out (Step S 208 ). 
     Then, the CPU  1  determines whether the printing of one page data is completed (Step S 209 ). 
     If “Yes” in Step S 209 , the CPU  1  determines whether all pages of backup data for one batch or case have been printed (Step S 210 ). 
     If “Yes” in Step S 209 , the CPU  1  checks whether all batches or cases of backup data have been printed (Step S 211 ). 
     If “Yes” in Step S 210 , the manual deletion process proceeds to Step S 197  to prepare for subsequent erasion of the backup data. 
     In Step S 211 , if all batches or cases of backup data have not been printed out (“No” in Step S 211 ), Step S 207  follows in a loop to prepare for printing the next batch of backup data. 
     In Step S 210 , if all pages of backup data have not been printed out (“No” in Step S 210 ), Step S 207  follows again to prepare for printing a new page of backup data. 
     In Step S 209 , if the printing of one page of backup data has not finished yet (“No” in Step S 209 ), the printing of the same page is continued by returning to Step S 208 . 
     In Step S 207 , if the count of the dot counter is more than the second threshold (“No” in Step S 207 ), the manual deletion process proceeds to Step S 204 . 
     In Step S 186 , if the mark flag is not “On” (“No” in Step S 186 ), the manual deletion process proceeds to Step S 206 . 
     In Step S 184 , if the printing of the backup data is not requested by the user (“No” in Step S 184 ), Step S 183  follows in a loop to wait for a user&#39;s input. 
     In Step S 183 , if the user prefers not to print out the backup data (“Yes” in Step S 183 ), the CPU  1  controls the display section  14  to display deletion inquiries (Step S 212 ). Specifically, the CPU  1  controls the display section  14  to alternately display two different inquiry indications at a predetermined time interval, as shown in FIGS. 18A and 18B. 
     Then, the CPU  1  determines whether the user has entered a delete-OK signal (Step S 213 ). Specifically, the CPU  1  checks whether the user has pressed the No.1 key of the numeral keys at the operation section  13 . 
     If “No” in Step S 213 , the CPU  1  determines whether the user has entered a Non-delete signal (Step S 214 ) Specifically, the CPU  1  checks whether the user has pressed the No.2 key of the numeral keys at the operation section  13 . 
     If “Yes” in Step S 214 , the manual deletion process proceeds to Step S 199  for canceling the print-busy indication and the print request inquiry indications without erasing the backup data. 
     If “No” in Step S 214 , Step S 213  follows in a loop to wait for a user&#39;s input. 
     In Step S 213 , if the user makes a delete-OK input (“Yes” in Step S 213 ), the manual deletion process proceeds to Step S 198  for deleting all of the backup data. 
     Moreover, the CPU  1  determines whether the input operation showing that the backup data can be erased is performed by the user (S 213 ). Specifically, the CPU  1  monitors an operation signal sent from the operation section  13  to check whether the user presses the ten-key “1”. 
     In Step S 181 , if no backup data is stored in the RAM  3  (“No” in Step S 181 ), the CPU  1  controls the display section  14  to so notify the user (Step S 215 ), and the manual deletion process proceeds to Step S 199 . Specifically, the CPU  1  causes the display section  14  to display a no-data indication for a period of two seconds for example, as shown in FIG.  19 . 
     In this way, the user has the option of deleting the backup data (fax-received data) in the RAM  3  by suitably operating the operation section  13 . 
     According to the embodiment described above, the operation of the printing section  12  is controlled depending on the mark flag, the backup flag and the presence or absence of disturbing light. However, it is not always necessary to use all of these factors for controlling purposes. For instance, t is possible to use only the mark flag or the combination of the mark flag and the backup flag regardless of the presence or absence of disturbing light. 
     Further, in the above-described embodiment, the backup data which have been already printed out are automatically deleted from the RAM  3  by a necessary amount at a time only when the RAM  3  becomes full. However, the user may select between an automatic data deletion mode and a non-automatic data deletion mode by operating a key switch at the operation section  13 . 
     The preferred embodiment of the present invention being thus described, it is obvious that the same may be varied in many ways. Such variations should not be regarded as a departure from the spirit and scope of the present invention, and all such variations as would be obvious to those skilled in the art are intended to be included in the scope of the following claims.