Patent Publication Number: US-2013250333-A1

Title: Image processing apparatus and communication control method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2012-066341 filed in Japan on Mar. 22, 2012. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an image processing apparatus and a communication control method. 
     2. Description of the Related Art 
     There have been developed a large number of image processing apparatuses such as multifunction peripherals (MFPs) that include, in addition to a copy function unit, a facsimile (fax) function unit that transmits and receives images over a public line and a printer function unit that forms an image on a recording medium according to image data received from a personal computer in recent years. 
     When main power supply to this type of image processing apparatus is cut off by power failure, all functions of the apparatus halt, and not only the copy function unit and the printer function unit but also an image-data communication operation by the fax function unit generally become disabled. 
     There are known image processing apparatuses that include a storage battery unit that supplies power source to make a fax function available even during power failure so that external communication capability is maintained even during power failure (see Japanese Patent Applications Laid-open 2008-185707 and H10-233867, for example). 
     However, a considerable amount of electric power is required to use the fax function during power failure. Accordingly, to make the facsimile function of such a conventional image processing apparatus available even during power failure, it is necessary to add a relatively-large storage battery unit such as a (uninterruptible power supply (UPS) or a secondary battery to the apparatus. This disadvantageously results in an increase in manufacturing cost. 
     Therefore, there is a need to provide an image processing apparatus capable of performing an image-data communication operation during power failure by using a storage battery unit that is already included in the apparatus, and a communication control method. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to an embodiment, there is provided an image processing apparatus that includes a communication unit configured to transmit and receive image data; an output unit configured to output the image data received by the communication unit; a storage battery unit used as a power source to back up the image data stored in a storage unit; a detecting unit configured to detect whether power supply from a main power source from to the image processing apparatus is cut off; and a power-supply control unit configured to perform a control operation that supplies electric power to the communication unit from the storage battery unit in a cutoff state where the detecting unit detects that the power supply from the main power supply is cut off. The communication unit performs, in the cutoff state, an image-data communication operation that consumes less power than a communication operation in a normal state where the detecting unit detects that the power supply from the main power supply is not cut off. 
     According to another embodiment, there is provided a communication control method performed in an image processing apparatus that includes a communication unit configured to transmit and receive image data, an output unit configured to output the image data received by the communication unit, a storage battery unit used as a power source to back up the image data stored in a storage unit, a detecting unit configured to detect whether power supply from a main power source from to the image processing apparatus is cut off, and a power-supply control unit configured to perform a control operation that supplies electric power to the communication unit from the storage battery unit in a cutoff state where the detecting unit detects that the power supply from the main power supply is cut off. The communication control method includes performing, by the communication unit performs, in the cutoff state, an image-data communication operation that consumes less power than a communication operation in a normal state where the detecting unit detects that the power supply from the main power supply is not cut off. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a hardware configuration of an image processing apparatus according to a first embodiment of the present invention; 
         FIG. 2  is a diagram for detailed description of a configuration of a network control unit (NCU); 
         FIG. 3  is a block diagram for detailed description of a configuration of a charging unit and a power-supply control unit; 
         FIG. 4  is a flowchart illustrating a processing sequence for transition to a power failure mode; 
         FIG. 5  is a flowchart illustrating processing to be performed by the image processing apparatus on detection of a startup trigger; 
         FIG. 6  is a flowchart illustrating processing to be performed by the image processing apparatus at recovery from power failure; 
         FIG. 7  is a flowchart illustrating a processing sequence to be performed by the image processing apparatus that reduces the number of types of interrupt triggers acceptable by the power-supply control unit during power failure; 
         FIG. 8  is a flowchart illustrating a processing sequence according to a second embodiment of the present invention; 
         FIG. 9  is a flowchart illustrating a processing sequence according to a third embodiment of the present invention; and 
         FIG. 10  is a flowchart illustrating a processing sequence according to a fourth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention are described below with reference to the accompanying drawings. 
     While image processing apparatuses and communication control methods according to the embodiments are applicable to any image processing apparatus, such as an MFP, having at least a function, such as a fax function, of transmitting/receiving image data, described in the following specification are examples in which the embodiments are each applied to an MFP. 
     An outline of a hardware configuration of an image processing apparatus  1  according to a first embodiment of the present invention is described below. 
       FIG. 1  is a block diagram schematically illustrating the hardware configuration of the image processing apparatus  1  according to the first embodiment. As illustrated in  FIG. 1 , the image processing apparatus  1  according to the first embodiment includes a controller (CTL)  2 , a fax control unit (FCU)  3 , an image reading unit  4 , an image forming unit  5 , and an operating unit  6 . The FCU  3 , the image reading unit  4 , the image forming unit  5 , and the operating unit  6 , which are constituting elements of the image processing apparatus  1  excluding the CTL  2 , are connected to the CTL  2 . 
     The CTL  2  has overall control of processing of the whole image processing apparatus  1 . The CTL  2  includes a central processing unit (CPU), a read only memory (ROM), and a random access memory (RAM). An engine control unit (not shown) is also connected to the CTL  2 . The CTL  2  controls the image reading unit  4  and the image forming unit  5  that serve as an engine unit via the engine control unit. 
     The FCU  3  is a unit that performs a fax communication operation involved in the fax function. The FCU  3  according to the first embodiment includes a plurality of constituting elements (also referred to as “devices”) including a CPU  301 , a ROM  302 , a RAM  303 , a modem  304 , a network control unit (NCU)  305 , a nonvolatile RAM  306 , a charging unit  307 , a switch (SW)  308 , a power-supply control unit  309 , a power supply unit  310 , a power-failure detecting unit  311 , and a voltage detection circuit  312 . 
     The CPU  301  that includes a microprocessor controls processing of the whole FCU  3 . Superficially, the CPU  301  executes program instructions stored in the ROM  302 , thereby controlling the RAM  303 , the modem  304 , the NCU  305 , the nonvolatile RAM  306 , and the like. 
     The ROM  302  stores therein various data and the program instructions for use by the CPU  301 . The RAM  303  is used to store data that is being processed. Specifically, the RAM  303  stores therein binary image data obtained by scanning by the image reading unit  4 . The RAM  303  also stores therein binary image data which are to be output to a telephone line  7  via the NCU  305  as signals modulated by the modem  304 . The RAM  303  also stores therein binary image data which are analog waveform signals input from the telephone line  7  and demodulated through the NCU  305  and the modem  304 . 
     The modem  304  converts between analog waveform signals for the telephone line  7  and binary image data for use in the image processing apparatus  1 . Specifically, the modem  304  includes a Group 3 fax (G3) modem (not shown) and a clock generating circuit (not shown) connected to the G3 modem. Under control of the CPU  301 , the modem  304  generates analog waveform signals to be transmitted by modulating binary image data stored in the RAM  303 , and outputs the signals to the telephone line  7  via the NCU  305 . The modem  304  also causes the NCU  305  to deliver analog waveform signals fed over the telephone line  7  to the modem  304 , demodulates the analog waveform signals into binary image data, and stores the image data in the RAM  303 . 
     The NCU  305  controls connection of the image processing apparatus  1  to the telephone line  7 , which is a public communication network. Specifically, the NCU  305  performs switching under control of the CPU  301 , thereby connecting the telephone line  7  to any one of the modem  304  and a telephone  8 . The NCU  305  includes a ringing signal detector. When a ringing signal is detected, the NCU  305  outputs an incoming call signal to the power-supply control unit  309 . The telephone  8  is externally connected to the FCU  3 . The telephone  8  includes, for instance, a handset, a speech network, a dialer, number keys, and a One-Touch key (none of these are shown). 
     The nonvolatile RAM  306  stores therein data (e.g., speed dial numbers) that needs to be stored even under a state where power supply to the FCU  3  is cut off. 
     The charging unit  307  is for use as a backup power source that prevents loss of data that is being stored in a case where power supply to the image processing apparatus  1  from a commercial power source (hereinafter, also referred to as “main power supply”) is cut off while the data is being stored in the RAM  303 . Specifically, the charging unit  307  includes a secondary battery (storage battery unit)  307 A that stores electric power supplied from the commercial power source and a regulator (charging unit)  307 B (see  FIG. 3 ) for use in charging the secondary battery  307 A. 
     The SW  308  is provided to switch power supply to loads of the FCU  3  between power supply from the commercial power source and power supply from the charging unit  307  serving as the backup power source. 
     The power-supply control unit (microcomputer)  309  controls power supply to each device of the FCU  3 . The power-supply control unit  309  according to the first embodiment is connected to two power systems, or, more specifically, the commercial power source (main power supply (+5 V)) and the secondary battery  307 A, via the power supply unit  310 . The power-supply control unit  309  has a normal mode in which electric power is supplied to all the devices that make up the FCU  3  and a power failure mode for the cutoff state (also referred to as “power failure state”) in which the main power supply is cut off due to power failure, breaking of wire, or the like. In the power failure mode, execution of program instructions is stopped and only startup triggers as interruptions are accepted. In the normal mode, electric power is supplied to the power-supply control unit  309  from the main power supply, while, in the power failure mode, electric power is supplied to the power-supply control unit  309  from the secondary battery  307 A. 
     The power supply unit  310  is a switching power source that controls on/off of power supply to the loads of the FCU  3 . Specifically, the power supply unit  310  starts or stops power supply to the devices of the FCU  3  on a device-by-device basis according to a startup signal or a stop signal supplied from the power-supply control unit  309 . 
     The power-failure detecting unit  311  detects whether the image processing apparatus  1  is supplied with electric power from the commercial power source. 
     The voltage detection circuit  312  detects a voltage of the secondary battery  307 A to determine a discharge status. 
     The image reading unit  4  is a unit that performs an image reading operation involved in a scanner function. Specifically, the image reading unit  4  includes a direct memory access (DMA) controller, an image processing integrated circuit (IC), an image sensor, and a complementary metal oxide semiconductor (CMOS) logic IC (none of these are shown), for example. The image reading unit  4  reads an image of a document placed on an automatic document feeder (ADF) (not shown) or an exposure glass (not shown) utilizing a contact sensor (CS), converts the read data into binary date, and sequentially sends the binary data to the RAM. 
     The image forming unit  5  is a unit that performs an image forming operation involved in a printer function. Specifically, the image forming unit  5  includes a monochrome plotter or a color plotter, an application specific integrated circuit (ASIC), and a fixing device, for example. The image forming unit  5  performs various image processing such as error diffusion and gamma conversion on image data read by the image reading unit  4  and stored in the RAM  303 , image data received from an external device such as a personal computer via a network (not shown), or image data received as a fax over the telephone line  7 , and forms an image on a recording medium such as recording paper according to the image-processed image data. 
     The operating unit  6  receives an operating input from a user. Specifically, the operating unit  6  includes a button for starting fax transmission as image transmission, fax reception as image reception, and the like, a mode select key for selecting an operating mode(s) such as a fine mode, a standard mode, and an auto-receipt mode for fax communication, number keys for dialing, and a One-Touch key. 
     The configuration of the NCU  305  is described in detail below. 
       FIG. 2  is a diagram for detailed description of the configuration of the NCU  305 . As illustrated in  FIG. 2 , the NCU  305  includes a photocoupler  305 A and a photocoupler  305 B. 
     The photocoupler  305 A is provided to detect a ringing signal. The photocoupler  305 A operates in such a manner that when the photocoupler  305 A receives a ringing signal over the telephone line  7 , an input of low level (an incoming call signal) RINGDET_N is fed to the power-supply control unit  309 . 
     The photocoupler  305 B is provided to detect off-hook. The photocoupler  305 B operates in such a manner that when the telephone  8  is off hook, an input of low level OFFHOOK_N is fed to the power-supply control unit  309 . 
     The configuration of the charging unit  307  and the power-supply control unit  309  is described in detail below. 
       FIG. 3  is a block diagram for detailed description of the configuration of the charging unit  307  and the power-supply control unit  309 . As illustrated in  FIG. 3 , the charging unit  307  includes the secondary battery  307 A and the regulator  307 B. The charging unit  307  charges the secondary battery  307 A utilizing the regulator  307 B. Specifically, when performing charging, the charging unit  307  causes the regulator  307 B to output by pulling EN pin to high. With this configuration, because the EN pin is pulled high only during charging, unnecessary power consumption can be reduced. 
     As illustrated in  FIG. 3 , the power-supply control unit  309  includes input pins including RINGDET_N, OFFHOOK_N, and TIMER_N for detecting various startup triggers for use in fax communication. The power-supply control unit  309  is capable of exchanging data to and from the CPU  301  via a serial interface input/output (I/O) and sends a notification to the CPU  301  about a startup trigger and a power supply state (a signal indicating whether electric power is supplied from the commercial power source) at startup. Accordingly, the CPU  301  changes startup control of the FCU  3  according to information sent from the power-supply control unit  309  as the notification. 
     Meanwhile, RINGDET_N goes low when a ringing signal is received. OFFHOOK_N goes low when the externally connected telephone  8  becomes off hook. TIMER_N goes low when preset time for fax transmission comes. The power-supply control unit  309  obtains information indicating current time from a real time clock (RTC) (not shown). 
     The power-supply control unit  309  also includes an input pin for detecting BATDET_N. Meanwhile, BATDET_N goes high when an output voltage of the secondary battery  307 A detected by the voltage detection circuit  312  is higher than a predetermined voltage, while BATDET_N goes low when the detected output voltage of the secondary battery  307 A is lower than the predetermined voltage. 
     Processing to be performed by the image processing apparatus  1  according to the first embodiment is described below. 
     First, a processing sequence to be performed by the image processing apparatus  1  for transition to the power failure mode is described below. 
       FIG. 4  is a flowchart illustrating the processing sequence for the transition to the power failure mode. As illustrated in  FIG. 4 , in the image processing apparatus  1 , when electric power is supplied to the power-supply control unit  309  from the secondary battery  307 A (Step S 101 ) because the commercial power source is cut off due to power failure, wire breakage, or the like, initialization of the power-supply control unit  309  is performed (Step S 102 ). After completion of the initialization, the power-supply control circuit  309  of the image processing apparatus  1  starts detecting interruption triggered by a startup trigger such as RINGDET_N (Step S 103 ). 
     Next, processing to be performed by the image processing apparatus  1  on detection of a startup trigger is described below. 
       FIG. 5  is a flowchart illustrating processing to be performed by the image processing apparatus  1  on detection of a startup trigger.  FIG. 5  illustrates an example processing sequence for a case in which RINGDET_N for fax reception is detected as the startup trigger. 
     As illustrated in  FIG. 5 , in the image processing apparatus  1 , when RINGDET_N is detected as the startup trigger (Yes at Step S 201 ), the power-supply control unit  309  determines whether electric power is supplied from the commercial power source or, in other words, whether the apparatus is in a cutoff state (hereinafter, also referred to as the “power failure state”) in which the commercial power source is cut off due to power failure, wire breakage, or the like based on a notification sent from the power-failure detecting unit  311  (Step S 202 ). 
     When it is determined that the apparatus is not in the power failure state (No at Step S 202 ), the power-supply control unit  309  controls the power supply unit  310  to cause all the devices that make up the FCU  3  to be supplied with electric power from the commercial power source, thereby starting up the FCU  3  in a normal manner (Step S 203 ). 
     Thereafter, the CPU  301  is initialized in the FCU  3  (Step S 204 ). Subsequently, the power-supply control unit  309  sends to the CPU  301  a notification about the startup trigger and a power supply state (specifically, in this situation, a signal indicating that the commercial power source is supplied) (Step S 205 ). On receiving the notification, the CPU  301  performs startup processing in the normal mode. 
     Subsequently, the CPU  301  initializes all the devices that make up the FCU  3  (Step S 206 ). Thereafter, the FCU  3  completes a receiving operation through a normal startup sequence (Step S 207 ). When image data has been received, the received image data is subjected to processing such as modulation performed by the modem  304 , and stored in the RAM  303  in the FCU  3 . The image processing apparatus  1  forms an image on a recording medium using the image forming unit  5  as an output task that outputs the image data stored in the RAM  303 . 
     Thereafter, the power-supply control unit  309  cuts off (turns power off) power supply to all the devices that make up the FCU  3  (Step S 208 ). Note that electric power is supplied to the power-supply control unit  309  from the secondary battery  307 A in this state. After processing at Step S 208 , the image processing apparatus  1  completes the sequence. 
     On the other hand, when it is determined that the apparatus is in the power failure state (Yes at Step S 202 ), the power-supply control unit  309  turns on the SW  308  and controls the power supply unit  310  to cause the secondary battery  307 A to supply electric power to all the devices that make up the FCU  3  (Step S 209 ). Accordingly, the FCU  3  starts up. 
     Thereafter, in the FCU  3 , the CPU  301  is initialized (Step S 210 ). Subsequently, the power-supply control unit  309  sends to the CPU  301  a notification about the startup trigger and a power supply state (in this situation, specifically, a signal indicating that the commercial power source is not supplied) (Step S 211 ). On receiving the notification, the CPU  301  performs startup processing in the power failure mode. 
     Subsequently, the CPU  301  initializes only predetermined devices as minimum processing for fax reception; in other words, the CPU  301  does not configure settings that are unnecessary for fax reception (Step S 212 ). Thereafter, when image data has been received, the received image data is subjected to processing such as modulation performed by the modem  304  and stored in the RAM  303  (Step S 213 ). 
     Thereafter, in the FCU  3 , the power-supply control unit  309  cuts off power supply to all the devices that make up the FCU  3  excluding the power-supply control unit  309  and the RAM  303  (Step S 214 ). 
     Processing to be performed by the image processing apparatus  1  at recovery from power failure is described below. 
       FIG. 6  is a flowchart illustrating processing to be performed by the image processing apparatus  1  at recovery from power failure. The sequence illustrated in  FIG. 6  starts on a precondition that image data received in the power failure mode is stored in the RAM  303 . 
     As illustrated in  FIG. 6 , in the image processing apparatus  1 , when the power-supply control unit  309  determines based on a notification from the power-failure detecting unit  311  that electric power is supplied from the commercial power source or, put another way, power failure has ended (Yes at Step S 301 ), the power-supply control unit  309  controls the power supply unit  310  to cause all the devices that make up the FCU  3  to be supplied with electric power via the commercial power source, thereby starting up the FCU  3  in the normal manner (Step S 302 ). 
     Thereafter, in the FCU  3 , the CPU  301  is initialized (Step S 303 ). Subsequently, the power-supply control unit  309  sends to the CPU  301  a notification about a power supply state (in this situation, the signal indicating that the commercial power source is supplied) (Step S 304 ). On receiving the notification, the CPU  301  performs startup processing in a power failure recovery mode. 
     Subsequently, the CPU  301  initializes all the devices that make up the FCU  3  (Step S 305 ). Thereafter, the CPU  301  performs an output task that outputs the image data stored in the RAM  303  (Step S 306 ). Accordingly, the image forming unit  5  forms an image on a recording medium according to the image data stored in the RAM  303  under control of the CTL  2 . 
     Thereafter, the power-supply control unit  309  cuts off (turns power off) power supply from the commercial power source to all the devices that make up the FCU  3  (Step S 307 ). Note that electric power is supplied to the power-supply control unit  309  from the secondary battery  307 A in this state. After processing at Step S 308 , the image processing apparatus  1  completes the sequence. 
     With the configuration described above, the image-data output task, which is a remaining task of the fax receiving operation, is automatically performed at recovery from power failure without involvement of a user. Accordingly, such an undesirably situation that image data stored during power failure is left unprocessed or unintentionally deleted can be prevented. 
     Described below is processing to be performed by the image processing apparatus  1  that reduces the number of types of interrupt startup triggers acceptable by the power-supply control unit  309  in the power failure mode to a value smaller than that in the normal mode. 
       FIG. 7  is a flowchart illustrating a processing sequence to be performed by the image processing apparatus  1  that reduces the number of types of interrupt startup triggers acceptable by the power-supply control unit  309  in the power failure mode to a value smaller than that in the normal mode. As illustrated in  FIG. 7 , in the image processing apparatus  1 , when the power-supply control unit  309  determines based on a notification sent from the power-failure detecting unit  311  that electric power is not supplied from the commercial power source or, in other words, the apparatus is in the cutoff state in which the commercial power source is cut off due to power failure, wire breakage, or the like (Yes at Step S 401 ), subsequently, the power-supply control unit  309  enables RINGDET_N which is the interrupt startup trigger for fax reception, and disables OFFHOOK_N and TIMER_N which are interrupt startup triggers for fax transmission. Put another way, the power-supply control unit  309  restricts acceptable interrupt startup trigger only to RINGDET_N (receipt of a ringing signal) for fax reception (Step S 402 ). 
     When the configuration described above is employed, it becomes possible to disable operations involved in fax transmission in the power failure mode. As a result, power consumption of the secondary battery  307 A in the power failure mode can be reduced, and fax reception can be performed with a higher priority in the power failure mode. 
     Other embodiments of the present invention are described below. 
     A second embodiment of the present invention is described below. 
       FIG. 8  is a flowchart of a processing sequence according to the second embodiment, a modification of the processing sequence according to the first embodiment illustrated in  FIG. 5 . Specifically, the processing sequence illustrated in  FIG. 8  is obtained by modifying processing at Step S 209  of the processing sequence illustrated in  FIG. 5  to processing at Step S 509 . Only Step S 509  that differs from the corresponding step of the processing sequence illustrated in  FIG. 5  is described below, and description about the other identical steps is omitted. 
     At Step S 509 , the power-supply control unit  309  turns on the SW  308  and controls the power supply unit  310  to cause the secondary battery  307 A to supply electric power only to predetermined devices (e.g., the CPU  301 , the RAM  303 , the modem  304 , and the NCU  305 ) that are determined in advance as being involved in image data reception among the devices that make up the FCU  3 , in contrast to processing at Step S 209  of the processing sequence illustrated in  FIG. 5 . 
     With this configuration, because power consumption of the secondary battery  307 A in the power failure mode can be reduced, the power failure mode can be maintained for a longer period of time. 
     A third embodiment of the present invention is described below. 
       FIG. 9  is a flowchart of a processing sequence according to the third embodiment, a modification of the processing sequence according to the second embodiment illustrated in  FIG. 8 . Specifically, the processing sequence illustrated in  FIG. 9  is obtained by modifying processing at Step S 513  of the processing sequence illustrated in  FIG. 8  to processing at Step S 613 . Only Step S 613  that differs from the corresponding step of the processing sequence illustrated in  FIG. 8  is described below, and description about the other identical steps is omitted. 
     At Step S 613 , when image data has been received, the received image data is not modulated by the modem  304  but stored in the RAM  303  as it is, in contrast to processing at Step S 513  of the processing sequence illustrated in  FIG. 8  (and, accordingly, Step S 213  of the processing sequence illustrated in  FIG. 5 ). When this configuration is employed, it is preferable that the image processing apparatus  1  modulates the image data stored in the RAM  303  and stores the modulated image data in the RAM  303  again at recovery from power failure; thereafter, the image processing apparatus  1  forms an image on a recording medium based on the image data stored in the RAM  303  using the image forming unit  5  as an output task that outputs the image data. 
     With this configuration, the need of supplying electric power to the modem  304  from the secondary battery  307 A in the power failure mode is eliminated. Accordingly, because power consumption of the secondary battery  307 A in the power failure mode can be reduced, the power failure mode can be maintained for a longer period of time. 
     A fourth embodiment of the present invention is described below. 
       FIG. 10  is a flowchart of a processing sequence according to the fourth embodiment, a modification of the processing sequence according to the third embodiment illustrated in  FIG. 9 . Specifically, the processing sequence illustrated in  FIG. 10  is obtained by adding Steps S 715  and S 716  between “Yes” option at Step S 602  and Step S 609  of the processing sequence illustrated in  FIG. 9 . Put another way, Steps S 601  to S 608  of the processing sequence illustrated in  FIG. 9  correspond to Steps S 701  to S 708  of the processing sequence illustrated in  FIG. 10 ; Steps S 609  to S 614  of the processing sequence illustrated in  FIG. 9  correspond to Steps S 709  to S 714  of the processing sequence illustrated in  FIG. 10 . Only Steps S 715  and S 716  that differ from the corresponding steps of the processing sequence illustrated in  FIG. 9  are described below, and description about the other identical steps is omitted. 
     Specifically, when the apparatus is determined to be in the power failure state at Step S 702  (Yes at Step S 702 ), the power-supply control unit  309  detects a remaining power level of the secondary battery  307 A (Step S 715 ). Subsequently, the FCU  3  determines whether the remaining power level of the secondary battery  307 A detected at Step S 715  is equal to or higher than a preset value (Step S 716 ). When the remaining power level of the secondary battery  307 A is determined to be equal to or higher than the preset value (Yes at Step S 716 ), the image processing apparatus  1  proceeds to Step S 709 . 
     On the other hand, when the remaining power level of the secondary battery  307 A is determined to be lower than the preset value (No at Step S 716 ), the image processing apparatus  1  completes this sequence without performing the fax receiving operation or, put another way, the image-data receiving operation. 
     With this configuration, an undesirable situation that, for example, the secondary battery  307 A becomes exhausted during a fax receiving operation, resulting in loss of received image data can be prevented. 
     According to the embodiments described above, the fax communication operation can be performed on electric power supplied from the secondary battery  307 A in a case of unexpected power cutoff caused by power failure, wire breakage, or the like. Accordingly, it becomes possible to perform the fax communication operation during power failure while the main power supply is cut off by utilizing the storage battery unit (the secondary power source), which is relatively small and already included in the image processing apparatus as a power source for backing up image data stored in the storage unit such as the RAM, without adding a relatively-large storage battery unit such as an UPS. As a result, an effect that an increase in manufacturing cost is avoided is obtained. 
     Note that preferred embodiments of the present invention include but not limited to the exemplary embodiments described above. 
     For example, in the embodiments described above, the present invention is applied to an MFP. However, application of the present invention is not limited thereto, but applicable to any other image processing apparatus having at least a function, such as a facsimile function, of transmitting/receiving image data. 
     In the embodiments described above, the image processing apparatus  1  includes the image forming unit  5 , but not limited thereto. The present invention is applicable to an image processing apparatus that includes an output unit that displays received image data on a display device, an output unit that transmits received image data to an external device such as a personal computer, or the like. 
     In the embodiments, the configuration in which electric power is consistently supplied to the RAM  303  in the power failure mode; this is because received image data is stored in the RAM  303  which is a volatile memory. However, applicable configuration is not limited thereto, and the present invention is applicable to a configuration in which a nonvolatile memory is provided in place of the RAM  303 , received image data is stored in the nonvolatile memory, and power supply to the nonvolatile memory is switched off in the power failure mode. 
     The program instructions for execution by the CPU of the embodiments can be provided as being stored in a storage unit, such as the ROM, of the image processing apparatus  1  in advance. The program instructions may be implemented in a computer program product embodied on a non-transitory tangible computer-readable storage medium stored therein the program instructions as file(s) in an installable or executable format. The program instructions can be provided or distributed over a network such as the Internet. 
     According to the embodiments, there is obtained an effect that an image-data communication operation can be performed during power failure using a storage battery unit, which is relatively small and already included in an image processing apparatus, without adding a relatively-large storage battery unit. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.