Abstract:
A communication device includes a communication unit configured to send and receive data via an attachable and detachable line, a power controller configured to reduce a power supply to the communication unit when a certain condition is satisfied, and a determination unit configured to determine whether or not a setting for sending and receiving data via the line by the communication unit is made. The power controller maintains the power supply to the communication unit at a call-receivable level, if it is determined that the setting for using the line is made.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority based on 35 USC 119 from prior Japanese Patent Application No. 2012-039690 filed on Feb. 27, 2012, entitled “COMMUNICATION DEVICE AND CONTROL DEVICE”, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This disclosure relates to a communication device and a control device. 
     2. Description of Related Art 
     Recently in Europe, it became a requirement that energy-using products need to satisfy the EuP (Directive on Eco-Design of Energy-using Products) Lot 6 standard for energy conservation. According to this standard, a device needs to have a power management function. To be specific, when the device is not operated for a certain time period, it must automatically transition to a power-off mode. 
     In this connection, Patent Document 1 (Japanese Patent Application Publication No. Hei 7-273866) describes a telephone device that is configured to judge that a connection failure occurs when a line voltage monitoring unit detects that a line voltage is not higher than a preset certain voltage after the elapse of a preset stable time since a closure of the line. Upon detecting this condition, the telephone device gives a connection failure notification. 
     SUMMARY OF THE INVENTION 
     A device provided with a communication function is no longer able to receive calls if the device is automatically powered off upon satisfaction of a certain power-off condition, such as the device not being operated for a certain time period. For this reason, there are some devices provided with a communication function (e.g., a multifunction device including a facsimile function) which has a setting option to disable the automatic power-off. This type of device requires a user to take the trouble to perform the setting, which is bothersome as another function the user has to perform. 
     An objective of an embodiment of the invention is to provide a communication device and a control device which do not require a particular user operation for keeping the communication device from being automatically powered off and becoming unable to receive calls. 
     A first aspect of the invention is a communication device including: a communication unit configured to send and receive data via an attachable and detachable line; a power controller configured to reduce the power supply to the communication unit when a certain condition is satisfied; and a determination unit configured to determine whether or not a setting is made for sending and receiving data via the line by the communication unit. If it is determined that the setting for using the line is made, the power controller maintains the power supply to the communication unit at a call-receivable level 
     A second aspect of the invention is a facsimile device including the communication device according to the first aspect. 
     A third aspect of the invention is a control device of a communication device including a communication unit configured to exchange data with a line. The control device includes: a power-off unit configured to cut off the power supply to the communication unit when a certain power-off condition is satisfied; and a determination unit configured to determine whether or not a certain setting is made for the communication unit to exchange data with the line. The power-off unit avoids cutoff of the power supply if the determination unit determines that the certain setting is made. 
     According to these aspects of the invention, it is possible to provide a communication device and a control device which do not require a particular user operation in order to keep the device from being automatically powered off and being unable to receive calls. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a configuration of a communication device of Embodiment 1. 
         FIG. 2  is a perspective view of a whole system including the communication device. 
         FIG. 3  is a block diagram showing a configuration of a line I/F unit. 
         FIG. 4  is a diagram showing a configuration of a hybrid network. 
         FIG. 5  is a block diagram showing a configuration of a controller. 
         FIG. 6  is a flowchart showing an operation of the controller of Embodiment 1. 
         FIG. 7  is a flowchart showing an operation of a controller of Embodiment 2. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Descriptions are provided hereinbelow for embodiments based on the drawings. In the respective drawings referenced herein, the same constituents are designated by the same reference numerals and duplicate explanation concerning the same constituents is omitted. All of the drawings are provided to illustrate the respective examples only. 
     Hereinafter, embodiments of the invention are described according to the drawings. 
     Embodiment 1 
       FIG. 1  is a block diagram showing a configuration of communication device  1  of Embodiment 1. Communication device  1  is a communication terminal device communicating with line (or network)  2 . Specifically, communication device  1  is a device capable of providing multiple functions to a user, and includes one or more functions for executing processing in response to a user operation, other than the communication function. In the embodiments, communication device  1  is a multifunction device provided with at least one of a facsimile function as a communication function, a copy function, and a printer function. Here, line  2  is a telephone line. 
     In  FIG. 1 , communication device  1  includes reader  10 , printer  11 , display unit  12 , operation unit  13 , image memory  14 , encoder/decoder  15 , communication unit  16 , nonvolatile memory unit  19 , RAM (Random Access Memory)  20 , power supply unit  21 , controller  22 , and data bus  23 . 
     Reader  10  reads an original document to be sent by facsimile or an original to be copied, and converts it into image data. 
     Printer  11  prints an image. To be specific, printer  11  prints image data acquired by reader  10  or image data received by communication unit  16 . 
     Display unit  12  displays information such as an operation state of communication device  1 , and includes a liquid crystal display (LCD) and a light emitting diode (LED), for example. 
     Operation unit  13  is a user interface for receiving operations for communication device  1  from the user, and is formed of a numeric keypad, a start/stop key for starting and stopping various operations, and the like. 
     Image memory  14  is a memory for accumulating image data. Specifically, image memory  14  stores therein transmission image information which is image data to be sent by facsimile and read by reader  10 , and reception image data which is image data received by facsimile by communication unit  16 . 
     Encoder/decoder  15  compresses transmission image information stored in image memory  14  by a certain coding scheme such as Modified Huffman (MH) coding, Modified READ (Relative Element Address Designate) (MR) coding, and Modified Modified READ (Relative Element Address Designate) (MMR) coding. Encoder/decoder  15  also expands reception image information stored in image memory  14  by a certain decoding scheme such as MH decoding, MR decoding, and MMR decoding. 
     Communication unit  16  exchanges data with line  2 . In the example in  FIG. 1 , communication unit  16  includes modem  17  and line I/F unit  18 . 
     Modem  17  modulates transmission facsimile data acquired by encoder/decoder  15  and outputs it to line I/F unit  18 . Modem  17  also demodulates facsimile data received by line I/F unit  18  and stores reception image information in image memory  14 . 
     Line I/F unit  18  is a communication interface for exchanging data with line  2 . To be specific, line I/F unit  18  sends modulated facsimile data received from modem  17  to line  2 . Line I/F unit  18  also receives facsimile data from line  2  and sends it to modem  17 . Line I/F unit  18  performs certain network control according to the control by controller  22 , at the time of transmission and reception of calls 
     Nonvolatile memory unit  19  is a readable/writable nonvolatile memory for storing information such as various control programs, and is a flash ROM, for example. Nonvolatile memory unit  19  includes information registration unit  191  in which information used by communication unit  16  for data exchange (e.g., facsimile transmission and reception) with line  2  can be registered. Specifically, information registration unit  191  accepts registration of information by the user via operation unit  13  or the like, and stores the information. Information stored in information registration unit  191  includes address information on communication destinations and own-device information, for example. Examples of address information include: destination telephone numbers such as abbreviated dial numbers and one-touch dial numbers; and caller telephone numbers based on which it is judged whether or not to receive a call from a caller telephone number sent from an exchange for a calling line identification service or the like in a call-incoming event. Own-device information is the telephone number of the own device (communication device  1  itself), for example. 
     RAM  20  is a memory for storing various data, and is used as a work area or the like for overall control of the communication device. 
     Power supply unit  21  receives a supply of power from external power supply  3  of communication device  1 , and supplies power to units of communication device  1 . In the embodiments, power supply unit  21  is: connected to an AC power supply (specifically, a commercial power supply) serving as external power supply  3 ; a low-voltage power supply which converts AC output from the AC power supply into a DC output and supplies it to the units of communication device  1 ; and a power source of operations of the units of communication device  1 . 
     Controller  22  performs the overall control of communication device  1 . Specifically, controller  22  includes a central processing unit (CPU), and controls the entire communication device according to various control programs stored in nonvolatile memory unit  19  while using RAM  20  as a work area. Controller  22  has an automatic power-off function for automatically (i.e., without the need for a power-off operation by the user) cutting off power supply to communication unit  16  or to other units when a certain power-off condition is satisfied. Details of this function are described later. Data bus  23  mutually connects the aforementioned units of communication device  1 . 
       FIG. 2  is a perspective view showing an entire system including communication device  1 . As shown in  FIG. 2 , communication device  1  is connected to connector  2   c  of line  2  via communication cable  4 , and is connected to the AC power supply serving as external power supply  3  via power cable  5 . 
       FIG. 3  is a block diagram showing a configuration of line I/F unit  18 . In  FIG. 3 , line I/F unit  18  includes terminals L 1 , L 2 , lightning surge protection element  181 , diode bridge  182 , network-side circuit  183 , isolation and transfer unit  184 , and controller-side circuit  185 . Specifically, line I/F unit  18  is provided with a silicon Data Access Arrangement (DAA) formed of network-side circuit  183 , controller-side circuit  185 , and isolation and transfer unit  184  which galvanically isolates the two circuits from each other and transfers data and signals therebetween. 
     Terminals L 1 , L 2  are terminals to be connected to line  2 . The pair of terminals L 1 , L 2  are provided with lightning surge protection element  181  such as a varistor connected therebetween, and are respectively connected to terminals A, B of diode bridge  182 . Terminal C on the plus side and terminal D on the minus side of diode bridge  182  are connected to line voltage detector  1831  in network-side circuit  183 . Line voltage detector  1831  detects a line voltage of line  2 . A detection output of line voltage detector  1831  is connected to line-side isolation I/F unit  1834  in network-side circuit  183 . Terminals C, D of diode bridge  182  are connected to hybrid network  1832  in network-side circuit  183 . Hybrid network  1832  includes impedance switch unit  1835  and DC resistance switch unit  1836 . Hybrid network  1832  is connected to AD/DA converter  1833  and line-side isolation I/F unit  1834 . Line-side isolation I/F unit  1834  is connected to isolation and transfer unit  184 . Isolation and transfer unit  184  is connected to controller-side isolation I/F unit  1851  in controller-side circuit  185 . Controller-side isolation I/F unit  1851  is connected to TX/RX IF unit  1852  and control I/F unit  1853  in controller-side circuit  185 . TX/RX IF unit  1852  is connected to modem  17 , and control I/F unit  1853  is connected to controller  22 . 
       FIG. 4  is a diagram showing a configuration of hybrid network  1832 . Hybrid network  1832  includes impedance switch unit  1835  and DC resistance switch unit  1836 . Impedance switch unit  1835  includes low impedance  18351  and high impedance  18352 , and switches the impedance between low impedance  18351  and high impedance  18352  according to the control performed by controller  22  (specifically, later-mentioned impedance switch instruction unit  221 ). DC resistance switch unit  1836  includes low DC resistance  18361  and high DC resistance  18362 , and switches the DC resistance between low DC resistance  18361  and high DC resistance  18362  according to the control performed by controller  22  (specifically, later-mentioned DC resistance switch instruction unit  222 ). 
       FIG. 5  is a block diagram showing a configuration of controller  22 . In  FIG. 5 , controller  22  includes impedance switch instruction unit (Z instruction unit)  221 , DC resistance switch instruction unit (DCR instruction unit)  222 , monitor unit  223 , determination unit  224 , and power-off unit  225  as a power controller. 
     Impedance switch instruction unit  221  outputs an impedance switch instruction to impedance switch unit  1835 , and DC resistance switch instruction unit  222  outputs a DC resistance switch instruction to DC resistance switch unit  1836 . 
     Monitor unit  223  monitors operations performed on communication device  1 . Monitor unit  223  then measures the duration of a state where communication device  1  is not operated, the duration of a standby state where communication device  1  waits for a next operation, or the duration of an inactive state where communication device  1  is not activated. For example, monitor unit  223  measures the time elapsed from the end of the last action (or job), or from the last operation. Operations to be performed on communication device  1  include a user operation performed on operation unit  13  of communication device  1 , operation or instruction (e.g., a print request) from a user or an external device via a communication path such as line  2 , and the like. In this description, the operations performed on communication device  1  are user operations performed on operation unit  13 . 
     Determination unit  224  determines whether or not certain settings for exchanging data with line  2  by communication unit  16  are made. To be specific, in Embodiment 1, determination unit  224  determines whether or not information (e.g., address information) is registered in information registration unit  191 . 
     Power-off unit  225  cuts off the power supply to communication unit  16  when a certain power-off condition is satisfied. To be specific, the power-off condition is a condition for cutting off the power supply to communication unit  16  without a power-off operation by the user (automatically), and is done with the elapse of a certain time period with no operation performed on communication device  1  in this example. In other words, in this example, power-off unit  225  cuts off the power supply to communication unit  16  when no operation is performed on communication device  1  for a certain time period. Note, however, that the power-off condition is not limited to this, and may be a different condition such as when the current time reaches a certain time. Specifically, when time measured by monitor unit  223  reaches a certain time, power-off unit  225  controls power supply unit  21  such that the power supply from power supply unit  21  to communication unit  16  is cut off. The operation of cutting off the power supply to communication unit  16  may include a case of virtually cutting off the power supply to communication unit  16 , other than completely cutting off power supply to communication unit  16 . To be specific, power-off unit  225  may virtually cut off the power supply to the extent that a communication function of communication unit  16  is turned off, or to the extent that communication by communication unit  16  is disabled. Alternatively, power-off unit  225  may transition to an off-mode where all functions, or virtually all functions, of communication device  1  are turned off when a certain power-off condition is satisfied. In the off-mode, the power supply from power supply unit  21  to the units of communication device  1  is cut off, and power consumed by communication device  1  as a whole is 0.5 W or less, for example. 
     Note, however, that power-off unit  225  does not cut off the power supply if determination unit  224  determines that the aforementioned certain settings are made. In other words, even when the certain power-off condition is satisfied, power-off unit  225  maintains the power supply if determination unit  224  determines that the aforementioned certain settings are made. In Embodiment 1, power-off unit  225  does not cut off the power supply when determination unit  224  determines that information is registered in information registration unit  191 . 
       FIG. 6  is a flowchart showing an operation of controller  22  of Embodiment 1. Hereinafter, a description is given of the operation of controller  22  with reference to  FIG. 6 . The processing of  FIG. 6  is performed when communication device  1  is in a standby state (standby mode). 
     In the standby state of communication device  1 , controller  22  monitors operations by the user and determines whether or not the user operates communication device  1  (S 11 ). 
     If it is determined that the user operates communication device  1  (S 11 : YES), controller  22  makes communication device  1  transition from the standby state to an operation mode, performs various operations such as facsimile transmission and copying according to the operation of the user (S 12 ), and upon completion of the operation, resumes the standby state of communication device  1 , returning to step S 11 . 
     On the other hand, if it is determined that the user does not operate communication device  1  (S 11 : NO), controller  22  determines whether or not a predetermined time passes in the standby state, in other words, determines whether or not the user does not operate communication device  1  for a certain time (S 13 ). Specifically, controller  22  determines whether or not the time measured by monitor unit  223  exceeds the predetermined time. 
     If it is determined that the predetermined time passes (S 13 : YES), controller  22  proceeds to step S 14 , and if not (S 13 : NO), controller  22  returns to step S 11 . 
     In step S 14 , controller  22  determines whether or not address information is registered in information registration unit  191 . 
     If it is determined that address information is not registered in information registration unit  191  (S 14 : NO), controller  22  determines that the line is not connected (line disconnected), makes communication device  1  transition from the standby state to a power-off mode (S 15 ), and ends the processing. 
     On the other hand, if it is determined that address information is registered in information registration unit  191  (S 14 : YES), controller  22  determines that the line is connected (line connected), and does not make communication device  1  transition to the power-off mode but keeps it in the standby mode (i.e., power-on state) (S 16 ). 
     According to Embodiment 1 described above, the following effects (1) and (2) can be obtained. 
     (1) In Embodiment 1, the controller determines whether or not the certain settings for exchanging data with the line by the communication unit are made, and if it is determined that the certain settings are made, the controller does not cut off the power supply to the communication unit even when the certain power-off condition is satisfied. Accordingly, Embodiment 1 makes it possible to prevent the state of being unable to receive calls due to the cutoff of the power supply (i.e., the state of being automatically powered off), without requiring particular user operation. To be specific, user operation is made simpler than the case where the user has to take the trouble to perform settings in order to avoid automatic power-off of the device. 
     (2) In one aspect, the controller determines whether or not information is registered in the information registration unit, and if it is determined that information is registered, the controller does not cut off the power supply. Embodiment makes it possible to easily determine whether the communication unit is in use (or whether the communication unit is connected to the line), and thus to easily determine whether or not to avoid a cutoff of the power supply to the device. 
     Embodiment 2 
     Hereinafter, a communication device of Embodiment 2 is described. The communication device of Embodiment 2 is substantially the same as communication device  1  of Embodiment 1 described above, except for the processing performed by a determination unit. In the following description, parts similar to Embodiment 1 are omitted or simplified, and elements that are the same or correspond to those of Embodiment 1 are assigned the same symbols. 
     In Embodiment 2, determination unit  224  determines whether or not a connection (specifically, an electric connection) is established between communication unit  16  and line  2 . To be specific, determination unit  224  determines whether or not a line voltage is detected by line voltage detector  1831 . 
     Power-off unit  225  does not cut off the power supply if determination unit  224  determines that a connection is established between communication unit  16  and line  2 . In other words, even when a certain power-off condition is satisfied, power-off unit  225  maintains the power supply if determination unit  224  determines that the connection is established. 
       FIG. 7  is a flowchart showing an operation of controller  22  of Embodiment 2. Hereinafter, a description is given of the operation of controller  22  with reference to  FIG. 7 . The processing of  FIG. 7  is performed when communication device  1  is in a standby state (standby mode). 
     In the standby state of communication device  1 , controller  22  monitors operations by the user and determines whether or not the user operates communication device  1  (S 21 ). 
     If it is determined that the user operates communication device  1  (S 21 : YES), controller  22  makes communication device  1  transition from the standby state to an operation mode, performs various operations according to the operation of the user (S 22 ), and upon completion of the operation, resumes the standby state of communication device  1  to return to step S 21 . 
     On the other hand, if it is determined that the user does not operate communication device  1  (S 21 : NO), controller  22  determines whether or not a predetermined time passes in the standby state. In other words, the controller determines whether or not the user does not operate communication device  1  for a certain time (S 23 ). 
     If it is determined that the predetermined time passes (S 23 : YES), controller  22  proceeds to step S 29 , and if not (S 23 : NO), controller  22  returns to step S 21 . 
     In step S 24 , controller  22  checks the result of detection by line voltage detector  1831  to determine whether or not a line voltage is generated. 
     If it is determined that no line voltage is generated (S 24 : NO), controller  22  determines that the line is not connected (line disconnected), makes communication device  1  transition from the standby state to a power-off mode (S 25 ), and ends the processing. 
     On the other hand, if it is determined that a line voltage is generated (S 24 : YES), controller  22  determines that the line is connected (line connected), and does not make communication device  1  transition to the power-off mode but keeps it in the standby mode (or power-on state) (S 26 ). 
     According to Embodiment 2 described above, the following effects (3) and (4) can be obtained in addition to the effect (1) described above. 
     (3) In embodiment 2, the controller determines whether or not a connection is established between the communication unit and the line. If it is determined that the connection is established, the controller does not cut off the power supply to the communication unit even when the certain power-off condition is satisfied. Accordingly, Embodiment 2 makes it possible to more adequately determine whether or not to avoid a cutoff of the power supply to the device. 
     (4) In one aspect, the controller determines whether or not a line voltage is detected, and if it is determined that a line voltage is generated, the controller does not cut off the power supply. Embodiment 2 makes it possible to surely or easily determine whether or not a connection is established between the communication unit and the line. 
     Note that the controller of the aforementioned embodiments may be implemented by only a hardware resource such as an electronic circuit, or may be implemented as a combination of a hardware resource and software. In the case of being implemented as a combination of a hardware resource and software, the controller is implemented by executing a computer program by a computer, for example, and more specifically, is implemented by reading a computer program recorded in a recording medium, such as a ROM, by a main memory device and executing it by a central processing unit (CPU). The computer program may be provided by being recorded in a computer-readable recording medium such as an optical disc, or may be provided via a communication line such as the Internet. 
     The invention is not limited to the above embodiments, but may be implemented in various modes without departing from the gist of the invention. 
     For example, although a multifunction device with a facsimile function is used as an example of the communication device in the above description, the communication device may be other types of devices, such as a multifunction device with a telephone function, and the like. 
     In addition, although a telephone line is used as the line in the above description, the line may be other types of lines, such as a network line including the Internet line, and the like. The line is not limited to wired lines, but may be a wireless line. 
     The invention includes other embodiments in addition to the above-described embodiments without departing from the spirit of the invention. The embodiments are to be considered in all respects as illustrative, and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description. Hence, all configurations including the meaning and range within equivalent arrangements of the claims are intended to be embraced in the invention.