Abstract:
An electronic device is provided that is capable of dealing with data loss from a volatile memory that can be caused when power supply from a device power source is disconnected. Even if there is a setting to retain received data in the volatile memory until a printing instruction is given by a user, the electronic device, e.g., an image forming apparatus, prints received data without waiting for the user&#39;s printing instruction in a case where a backup battery voltage is less than a predetermined value.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an electronic device in which a volatile memory is battery-backed up when power supply from a device power source is disconnected, a control method therefor, and a storage medium storing a program for executing the control method. 
       BACKGROUND ART 
       [0002]    A volatile memory, which is incorporated in an electronic device such as an image forming apparatus, is normally supplied with power from a device power source (i.e., a power source of the electronic device), but from a backup battery when the power supply from the device power source is disconnected, whereby data can be kept retained in the volatile memory. 
         [0003]    In, e.g., PTL 1, a memory board is proposed that changes the power supply source for a volatile memory from a device body as a drive power source to a backup battery and prohibits writing to the volatile memory when a detected voltage of power supplied from the drive power source becomes equal to or less than a predetermined value. 
       CITATION LIST 
     Patent Literature 
       [0004]    {PTL 1} Japanese Laid-open Patent Publication No. H6-174809 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    There is an electronic device having a facsimile function and configured to retain received data in a volatile memory until a print-output instruction is given by a user. 
         [0006]    However, if a long period of time elapses after the power supply source for the volatile memory is changed from the device power source to the backup battery and before power supply from the device power source is restarted, power supply from the backup battery stops, so that data retained in the volatile memory is lost. 
         [0007]    With the memory board described in PTL  1  that only prohibits writing to the volatile memory when the power supply source for the volatile memory is changed from the drive power source to the backup battery, it is impossible to protect data held in the volatile memory when the power supply from the backup battery stops due to lapse of a long period of time after the change from the drive power source to the backup battery. 
         [0008]    The present invention provides an electronic device capable of dealing with data loss from a volatile memory that can be caused when power supply from a device power source is disconnected, a control method therefor, and a storage medium storing a program for executing the control method. 
       Solution to Problem 
       [0009]    Accordingly, one aspect of this invention provides an electronic device comprising a volatile memory configured to be supplied with power from a device power source or from a backup battery, a switching unit configured, in a case where power supply from the device power source is disconnected, to change a power supply source such that power is supplied from the backup battery to the volatile memory, a reception unit configured to receive data from an external device, a printing unit configured to print data received by the reception unit, and a setting unit configured to make a setting to retain data received by the reception unit in the volatile memory until a user&#39;s printing instruction is given, wherein in a case where a voltage of the backup battery is less than a predetermined value, data received by the reception unit is printed by the printing unit without waiting for the user&#39;s printing instruction, even if the setting to retain data in the volatile memory is made by the setting unit. 
         [0010]    The features and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. 
       Advantageous Effects of Invention 
       [0011]    With this invention, it is possible to deal with data loss from the volatile memory of the electronic device that can be caused when power supply from the device power source is disconnected. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1  A block diagram showing an example hardware structure of an image forming apparatus, which is an electronic device according to a first embodiment of this invention. 
           [0013]      FIG. 2  A flowchart showing an example operation of the image forming apparatus at FAX communication. 
           [0014]      FIG. 3  A flowchart showing an example operation of an image forming apparatus, which is an electronic device according to a second embodiment of this invention, at FAX communication. 
           [0015]      FIG. 4  A view showing an example of a printing selection screen displayed on an operation panel of the image forming apparatus during the FAX communication operation shown in  FIG. 3 . 
           [0016]      FIG. 5  A flowchart showing an example operation of an image forming apparatus, which is an electronic device according to a third embodiment of this invention, at FAX communication. 
           [0017]      FIG. 6  A view showing an example of a forced memory reception cancel screen displayed on an operation panel of the image forming apparatus during the FAX communication operation shown in  FIG. 5 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0018]    The present invention will now be described in detail below with reference to the drawings showing preferred embodiments thereof. 
         [0019]      FIG. 1  shows in block diagram an example hardware structure of an image forming apparatus, which is an electronic device according to a first embodiment of this invention. 
         [0020]    As shown in  FIG. 1 , the image forming apparatus  100  of this embodiment includes a printing unit  107 , reading unit  109 , operation panel  111 , and line I/F  113 , and includes a controller unit  101  that controls them. The image forming apparatus  100  also includes a power supply unit  119 . 
         [0021]    The controller unit  101  includes a CPU  102 , RAM  103 , ROM  104 , printing unit I/F  106 , reading unit I/F  108 , operation panel I/F  110 , modem  112 , and network I/F  118 , which are connected to a system bus  105 . 
         [0022]    The controller unit  101  further includes a power supply controller  116  to which the power supply unit  119  and a backup battery  121  are connected. The power supply unit  119  is a device power source that supplies power to respective parts of the image forming apparatus  100  (an illustration of power supply paths from the power supply unit  119  to respective apparatus parts is omitted in  FIG. 1 ). Under the control of the CPU  102 , the power supply controller  116  selects either the power supply unit  119  or the backup battery  121 , as the power supply source for the RAM  103 . It should be noted that the power supply controller  116  has a function of detecting the voltage of the backup battery  121 . 
         [0023]    The CPU  102  overall controls the image forming apparatus  100 . To this end, the CPU  102  loads a control program stored, e.g., in a program area of the ROM  104  or in an HDD (not shown) into the RAM (volatile memory)  103  and executes the loaded control program, thereby executing predetermined processing. 
         [0024]    When power supply from the power supply unit  119  is disconnected, the CPU  102  (switching unit) controls the power supply controller  116  to change the power supply source for the RAM  103  from the power supply unit  119  to the backup battery  121 , whereby power is supplied from the backup battery  121  to the RAM  103 . 
         [0025]    The network I/F  118  communicates with a PC (personal computer)  117  via a network  120  such as a LAN. The modem  112  is connected through the line I/F  112  and the public network  114  to an external device  115 , such as an image forming apparatus (other than the image forming apparatus  100 ), facsimile apparatus, and telephone set, for communication with the external device  115 . 
         [0026]    The printing unit I/F  106  is an interface that outputs an image signal to the printing unit (printer engine)  107 . The reading unit I/F  108  is an interface that inputs a reading image signal from the reading unit (scanner engine)  109 . 
         [0027]    The CPU  102  performs predetermined processing on the image signal input from the reading unit  109  via the reading unit I/F  108 , and outputs the processed image signal to the printing unit  107  via the printing unit I/F  106 . 
         [0028]    The operation panel  110  is an interface for input/output with the operation panel  111 . The CPU  102  outputs via the operation panel I/F  110  to the operation panel  111  data such as characters and symbols to be displayed on a display region of the operation panel  111  by using font information stored in a font area of the ROM  104 , whereby the data is displayed on the display region of the operation panel  111 . The CPU  101  accepts via the operation panel I/F  111  a user&#39;s instruction input through the operation panel  110 . 
         [0029]    The ROM  104  has a data area stored with apparatus information about the image forming apparatus  100 , user&#39;s telephone book information, etc. so as to be able to be read and updated by the CPU  102  as needed. 
         [0030]    Next, a description will be given of a facsimile (hereinafter referred to as the FAX) function of the image forming apparatus  100 . 
         [0031]    In FAX transmission, image data read by the reading unit  109  is temporarily retained in the RAM  103 , and then transmitted from the modem  112  to the external device  115  via the public network  114 . After completion of the transmission, the image data retained in the RAM  103  is deleted. 
         [0032]    In FAX reception, image data received from the external device  115  by the modem  112  via the public network  114  is retained in the RAM  103  and then output to the printing unit  107 . After completion of the printing of the image data by the printing unit  107 , the image data retained in the RAM  103  is deleted. 
         [0033]    The image forming apparatus  100  has a function of forced memory reception. The forced memory reception is set by the user by performing an operation for selecting the forced memory reception on the operation panel  111 . When the forced memory reception is set, image data received from the external device  115  by the modem  112  via the public network  114  is kept retained in the RAM  103 . When an operation for canceling the forced memory reception setting is performed by the user on the operation panel  111 , the image data is output to the printing unit  107 . After completion of the printing of the image data by the printing unit  107 , the image data retained in the RAM  103  is deleted. 
         [0034]    Even if the forced memory reception is set, when a detected voltage of the backup battery  121  becomes less than a predetermined value in a state that power is supplied from the power supply unit  119  to the RAM  103 , received image data is retained in the RAM  103  and output to the printing unit  107 . After completion of the printing of the image data by the printing unit  107 , the image data retained in the RAM  103  is deleted. 
         [0035]    Next, with reference to  FIG. 2 , an example operation of the image forming apparatus  100  at FAX communication will be described. In this example, it is assumed that power is supplied from the power supply unit  119  to the RAM  103 . 
         [0036]    In step S 201 , the CPU  102  determines whether there is data to be retained in the RAM  103 . If the answer to step S 202  is NO, the flow returns to step S 201 . On the other hand, if there is data to be retained in the RAM  103 , the flow proceeds to step S 202 . 
         [0037]    In step S 202 , the CPU  102  determines whether the data to be retained in the RAM  103  is FAX transmission data. If the data to be retained in the RAM  103  is FAX transmission data (i.e., if YES to step S 202 ), the flow proceeds to step S 206 . If the data to be retained in the RAM  103  is FAX reception data (i.e., if NO to step S 202 ), the flow proceeds to step S 203 . 
         [0038]    In step S 206 , the CPU  102  executes transmission processing. More specifically, the CPU  102  temporarily retains image data read by the reading unit  109  in the RAM  103 , transmits the image data to the external device  115  from the modem  112  via the public network  114 , and deletes the image data retained in the RAM  103  after completion of transmission of the image data, whereupon the flow returns to step S 201 . 
         [0039]    In step S 203 , the CPU  102  determines whether or not the forced memory reception is set. If the forced memory reception is not set, the flow proceeds to step S 207 . On the other hand, if the forced memory reception is set, the flow proceeds to step S 204 . 
         [0040]    In step S 207 , the CPU  102  executes reception processing. More specifically, the CPU  102  (reception unit) retains image data received by the modem  112  from the external device  115  via the public network  114  in the RAM  103 , outputs the image data to the printing unit  107 , and deletes the image data retained in the RAM  103  after completion of the printing of the image data by the printing unit  107 , whereupon the flow returns to step S 201 . 
         [0041]    In step S 204 , the CPU  102  determines whether a voltage of the backup battery  121  detected by the power supply controller  116  is less than a predetermined value. If the battery voltage is less than the predetermined value, the flow proceeds to step S 205 . If the battery voltage is equal to or greater than the predetermined value, the flow proceeds to step S 208 . 
         [0042]    In step S 208 , the CPU  102  executes forced memory reception processing in which image data received by the modem  112  from the external device  115  via the public network  114  is kept retained in the RAM  103 , whereupon the flow returns to step S 201 . It should be noted that when an operation to cancel the forced memory reception setting is performed by the user on the operation panel  111 , the CPU  102  outputs the image data retained in the RAM  103  to the printing unit  107 , and deletes the image data retained in the RAM  103  after completion of the printing of the image data by the printing unit  107 . 
         [0043]    In step S 205 , the CPU  102  (deletion unit) executes received data printing processing. More specifically, the CPU  102  retains image data received by the modem  112  from the external device  115  via the public network  114  in the RAM  103 , outputs the image data to the printing unit  107 , and deletes the image data retained in the RAM  103  after completion of the printing of the image data by the printing unit  107 , whereupon the flow returns to step S 201 . 
         [0044]    As described above, in this embodiment, in a case where the forced memory reception is set, received image data is retained in the RAM  103  and output to the printing unit  107  to print the image data when the voltage of the backup battery  121  is less than the predetermined value. It is therefore possible to deal with a situation where image data to be retained in the RAM  103  can be lost as a result that power supply from the power supply unit  119  is disconnected in a state that the voltage of the backup battery  121  becomes low and subsequent power supply from the backup battery  121  stops with lapse of time before the forced memory reception setting is cancelled by the user. 
         [0045]    Next, with reference to  FIGS. 3 and 4 , a description will be given of a FAX communication operation of an image forming apparatus, which is an electronic device according to a second embodiment of this invention.  FIG. 3  shows in flowchart an example operation of the image forming apparatus at FAX communication, and  FIG. 4  shows an example of a printing selection screen displayed on an operation panel of the image forming apparatus. It should be noted that the construction and operation of the image forming apparatus of this embodiment are basically the same as those of the first embodiment, and a description of points common to both the embodiments will be omitted. 
         [0046]    In  FIG. 3 , if it is determined by the CPU  102  in step S 204  that the voltage of the backup battery  121  is less than the predetermined value, the flow proceeds to step S 305 . If it is determined that the battery voltage is equal to or greater than the predetermined value, the flow proceeds to step S 208 . 
         [0047]    In step S 305 , the CPU  102  controls the operation panel  110  to display a printing selection screen for prompting the user to select whether a document should be printed, as shown in  FIG. 4 . If “YES (printing)” is selected by the user on the printing selection screen shown in  FIG. 4 , the flow proceeds to step S 205  where the CPU  102  executes the received data printing processing, which is already described with reference to  FIG. 2 . On the other hand, if “NO (non-printing)” is selected by the user, the flow proceeds to step S 208  where the CPU  102  executes the forced memory reception processing, which is already described with reference to  FIG. 2 . 
         [0048]    Next, with reference to  FIGS. 5 and 6 , a description will be given of a FAX communication operation of an image forming apparatus, which is an electronic device according to a third embodiment of this invention.  FIG. 5  shows in flowchart an example operation of the image forming apparatus at FAX communication, and  FIG. 6  shows an example of a forced memory reception cancel screen displayed on an operation panel of the image forming apparatus. It should be noted that the construction and operation of the image forming apparatus of this embodiment are basically the same as those of the first embodiment, and a description of points common to both the embodiments will be omitted. 
         [0049]    In  FIG. 5 , if it is determined by the CPU  102  in step S 204  that the voltage of the backup battery  121  is less than the predetermined value, the flow proceeds to step S 505 . If it is determined that the battery voltage is equal to or greater than the predetermined value, the flow proceeds to step S 208 . 
         [0050]    In step S 505 , the CPU  102  controls the operation panel  110  to display a forced memory reception cancel screen for prompting the user to select whether the forced memory reception setting should be cancelled, as shown in  FIG. 6 . If “YES (cancel)” is selected by the user on the selection screen shown in  FIG. 6 , the flow proceeds to step S 506 . On the other hand, if “NO (not cancel)” is selected by the user, the flow proceeds to step S 208  where the CPU  102  executes the forced memory reception processing, which is already described with reference to  FIG. 2 . 
         [0051]    In step S 506 , the CPU  102  cancels the forced memory reception setting. Then, the flow proceeds to step S 205  where the CPU  102  executes the received data printing processing, which is already described with reference to  FIG. 2 . 
         [0052]    While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
       REFERENCE SIGNS LIST 
       [0053]      100  Image forming apparatus 
         [0054]      101  Controller unit 
         [0055]      102  CPU 
         [0056]      103  RAM 
         [0057]      107  Printing unit 
         [0058]      111  Operation panel 
         [0059]      112  Modem 
         [0060]      115  External device 
         [0061]      119  Power supply unit (Device power source) 
         [0062]      121  Backup battery