JP5538299B2 - Communication apparatus and communication system - Google Patents

Description

  The present invention relates to a communication apparatus such as a facsimile apparatus that communicates with a counterpart apparatus via a network.

  In recent years, FAX communication is performed via a network (for example, the Internet). The FAX communication on this network may be performed using UDP (User Datagram Protocol). In FAX communication, some loss of image data may be fatal, but UDP has a part with low reliability, such as missing packet retransmission being not implemented. Therefore, in FAX communication using UDP, a previously sent packet may be added as a redundant packet to improve reliability. As a result, even if a part of the packet is lost, it is possible to check and recover the redundant packet sent from the next time. As a standard of such FAX communication using UDP, ITU-T recommendation T.30. There are 38. An example of a facsimile that sets the packet redundancy according to the reception state is described in Patent Document 1.

  Specifically, Patent Document 1 discloses traffic state estimation means for estimating a traffic state of transmission information data reaching a counterpart facsimile apparatus based on reception information data from a packet data network received before transmission information data is transmitted. And a transmission means for setting packet redundancy of the transmission information data based on the traffic state and transmitting the transmission information data to the counterpart facsimile apparatus according to the packet redundancy. Describes a facsimile data communication apparatus (facsimile data communication method) for transmitting and receiving in the form of a series of a plurality of packets. With this configuration, packet redundancy is changed according to the congestion state of the network (see Patent Document 1: Claims 1, 4, Paragraph [0008], etc.).

Japanese Patent No. 4124065

  In FAX communication using UDP, a redundant packet may be transmitted to improve reliability. However, if the number of packet redundancy is too large, communication is performed with a redundancy greater than necessary, and the time until the end of communication becomes longer. On the other hand, if the number of redundant packets is too small, the counterpart device may not be able to recover the received data. Therefore, it is preferable that the packet redundancy number is optimized by reducing the packet redundancy number as much as possible within a range in which the loss of the received data can be recovered.

  Here, the probability and extent of packet loss may vary depending on the communication path to the other party (depending on the other party's destination). On the other hand, the communication device (communication method) described in Patent Document 1 has a problem that the packet redundancy number cannot be optimized according to the destination because the packet redundancy is determined for each reception. In addition, the communication device (communication method) described in Patent Document 1 detects a packet drop every time it is received (see Patent Document 1: Paragraph [0020], etc.), but there is little change in the state of the line or network. There is also a problem that wasteful processing is performed.

  In view of the above problems, an object of the present invention is to perform communication with an optimum number of packet redundancy for each destination based on simple processing.

In order to solve the above problem, a communication device according to claim 1 is a communication unit that communicates with a counterpart device using UDP as a transport via a network, address information of each counterpart device, and a destination associated with the address information. Each having a storage unit for storing the packet redundancy number in UDP communication, the communication unit refers to the packet redundancy number associated with the address information, and the packet redundancy number determined in the storage unit In the direction of increasing the number of redundant packets used in communication with the partner device that has finished communication if there is an error in communication with the partner device that has finished communication after the communication is finished. If there is no error, the update is performed in a direction to reduce the number of redundant packets used in communication with the partner apparatus that has completed communication.

  According to this configuration, if there is an error in communication with the partner device that has finished communication after the end of communication, the storage unit updates in a direction to increase the packet redundancy number of the partner device that has finished communication, and there is no error. The communication unit is updated so as to reduce the packet redundancy number of the counterpart device that has finished communication, and the communication unit communicates with the counterpart device using the packet redundancy number stored in the storage unit. Thereby, the optimal number of packet redundancy can be determined for each destination. In addition, after the communication is completed (after the communication job), only the communication result is confirmed and the packet redundancy number is updated. Therefore, in order to determine the packet redundancy number during communication, the communication status confirmation process and the packet redundancy number change process are performed multiple times. The processing load on the communication device is reduced. Therefore, based on simple processing, communication can be performed with the optimum number of packet redundancy for each destination, and data can be transmitted reliably while minimizing the time required for transmission to the counterpart device.

Further, in the invention according to claim 2, in the invention of claim 1, the storage unit terminates communication after communication is completed if an error in communication with the counterpart device is an error related to packet transmission / reception . Update the packet redundancy number used in communication with the counterpart device to increase, and if the error is not related to packet transmission / reception, do not update the packet redundancy number used in communication with the counterpart device that ended communication after the communication ends. It was.

  According to this configuration, if the error in communication with the counterpart device is an error related to packet transmission / reception, the storage unit updates the packet redundancy number to increase after the communication ends, and if the error is not related to packet transmission / reception. The packet redundancy number is not updated after the communication is completed. As a result, when there is data loss that cannot be recovered by communication with the counterpart device and the packet redundancy number should be increased, the packet redundancy number is updated so that the packet redundancy number is increased from the next transmission. Therefore, the reliability of communication using UDP can be improved for each destination.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the storage unit has a value larger than the maximum value when the number of packet redundancy before update is a predetermined maximum value. The packet redundancy number is not updated.

  As the number of redundant packets increases, the effect of improving the reliability can be expected, but on the other hand, the time required to complete the communication becomes longer. Therefore, according to this configuration, when the packet redundancy number before update is a predetermined maximum value, the storage unit does not update the packet redundancy number to a value larger than the maximum value. Thereby, the upper limit of the packet redundancy number can be set and the packet redundancy number can be prevented from becoming abnormally long.

  In the invention according to claim 4, the storage unit does not update the packet redundancy number to a value smaller than the minimum value when the packet redundancy number before the update is a predetermined minimum value. did.

  The effect of shortening the time from the start to the end of communication can be expected as the number of packet redundancy is reduced, but on the other hand, recovery may be difficult when there is data loss in the communication path. Thus, according to this configuration, when the packet redundancy number before update is a predetermined minimum value, the storage unit does not update the packet redundancy number to a value smaller than the minimum value. Thereby, the lower limit of the packet redundancy number can be set, and the minimum reliability can be ensured.

  The invention according to claim 5 is the invention according to claims 1 to 4, wherein the storage unit increases or decreases the packet redundancy number by one.

  According to this configuration, the storage unit increases or decreases the packet redundancy number by one. As a result, the packet redundancy number can be brought close to the optimum value.

A communication system according to claim 6 includes a communication device and a counterpart device. The communication device communicates with the counterpart device using UDP as a transport via a network, and each of the counterpart devices. Address information and a storage unit that stores the packet redundancy number in UDP communication for each destination in association with the address information, the communication unit refers to the packet redundancy number associated with the address information, The communication unit communicates with the counterpart device using the packet redundancy number determined in the storage unit, and the storage unit is used for communication with the counterpart device in a communication job if there is an error in communication with the counterpart device after the end of communication. update in the direction of increasing the number of packets redundancy, if there is no error, and updates the direction of reducing the number of packets redundancy used in the communication with the partner apparatus that has performed the communication, phase Square device, as an error of communication, a signal representing a failed packet reception was decided to send to the communication unit.

  According to this configuration, the counterpart device transmits a signal indicating that packet reception has failed as a communication error to the communication unit, and the communication device storage unit has an error in communication with the counterpart device after the communication is completed. For example, the packet redundancy number of the counterpart device in the communication job is updated so as to increase, and if there is no error, the packet redundancy number of the counterpart device that performed communication is updated so as to decrease. Thus, the same effect as that of the first aspect of the invention can be obtained, and the communication apparatus can determine the optimum number of packet redundancy for each destination.

  According to the present invention, an optimum number of packet redundancy can be determined for each destination. Communication can be performed without using redundant packets unnecessarily. In addition, the process for determining the optimum packet redundancy number can be simplified.

It is explanatory drawing which shows an example of the communication system containing the multifunctional device which concerns on embodiment. 1 is a schematic front sectional view illustrating an example of a multifunction peripheral according to an embodiment. 1 is a block diagram illustrating an example of a hardware configuration of a multifunction machine according to an embodiment. It is explanatory drawing which shows an example of the transmission destination information registration screen which concerns on embodiment. It is explanatory drawing which shows an example of the address book screen in the multifunctional device which concerns on embodiment. It is explanatory drawing which shows an example of the sequence at the time of communication of the network FAX in the multifunctional device of this embodiment. It is explanatory drawing which shows an example of the structure of the UDP packet containing the redundant packet in the multifunctional device of an embodiment. It is a schematic diagram which shows an example of the concept of the transmission destination information memorize | stored in the memory | storage part of embodiment. 6 is a flowchart illustrating an example of a flow of updating a packet redundancy number in the multifunction peripheral according to the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, as an example of a communication apparatus that transmits and receives image data, a multifunction peripheral 100 (corresponding to a communication apparatus) having a network FAX function will be described. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Outline of communication system 10 using network)
An example of a communication system 10 using a network including the multifunction peripheral 100 according to the embodiment will be described. FIG. 1 is an explanatory diagram illustrating an example of a communication system 10 using a network including the multifunction peripheral 100 according to the embodiment.

  In FIG. 1, a multifunction peripheral 100 is provided as a communication device that transmits image data. The multifunction device 100 is connected to the IP network 200 and can perform FAX communication via the IP network 200. The multi-function device 100 is, for example, an ITU-T. FAX transmission can be performed based on 38 standards. The multifunction device 100 operates as a transmission side terminal when sending image data, and also operates as a reception side terminal that receives image data.

  Therefore, two or more MFPs 100 according to this embodiment (for convenience, only two are shown in FIG. 1) are connected to the IP network 200, and FAX communication can be performed between the MFPs 100 via the IP network 200. it can. For convenience, in FIG. 1, a multifunction device 100 (corresponding to a communication device) as a transmission side terminal is shown below, and the multifunction device 100 as a counterpart device (communication partner) of the multifunction device 100 in the following description is shown in the upper right of FIG. In the following, it may be referred to as “the other party multifunction device 100A”. For example, the multifunction device 100 and the counterpart multifunction device 100A may be of the same model.

  Also, ITU-T. A gateway 400 is provided between the G3 FAX apparatus 300 that performs G3 FAX communication conforming to the 30 standard and the IP network 200. The gateway 400 and the G3 FAX apparatus 300 are connected by a PSTN (public telephone line), and analog FAX communication is performed between the gateway 400 and the G3 FAX apparatus 300. The gateway 400 mediates in order to realize FAX communication with the G3 FAX apparatus 300 via the IP network 200. With this gateway 400, the MFP 100 (or the partner MFP 100A) can communicate with the G3 FAX apparatus 300 using the ITU-T. FAX communication conforming to the 38 standard can be performed. For example, the gateway 400 converts an analog signal from the G3 FAX apparatus 300 into a packet. The gateway 400 reconverts the packet into an analog signal and transmits the analog signal to the G3 FAX apparatus 300.

  The multi-function device 100 transmits image data or the like via the IP network 200 based on designated address information (for example, an IP address) to a counterpart device (for example, the multi-function device 100 conforming to the ITU-T.38 standard). And a network compatible FAX apparatus 500). Further, the multifunction peripheral 100 can transmit image data and the like to the G3 FAX apparatus 300 via the IP network 200 based on the IP address of the gateway 400 and the telephone number (FAX number) of the G3 FAX apparatus 300.

(Outline of MFP 100)
Next, the multifunction peripheral 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic front sectional view showing an example of the multifunction peripheral 100 according to the embodiment of the present invention.

  As shown in FIG. 2, the multifunction peripheral 100 (the multifunction peripheral 100 or the counterpart multifunction peripheral 100 </ b> A) of the present embodiment has a document cover 101 at the top, and an operation panel 2, an image reading unit 3, a paper feed in the main body. A unit 4a, a conveyance path 4b, an image forming unit 5a, a fixing unit 5b, a discharge conveyance unit 4c, and the like are provided.

  As shown in FIG. 2, the operation panel 2 is provided above the front surface of the multifunction device 100, and various images and screens such as menus and keys for giving settings and operation instructions of the multifunction device 100 and status messages of the multifunction device 100. Has a liquid crystal display unit 21 for displaying. A touch panel unit 22 is provided on the upper surface of the liquid crystal display unit 21. The touch panel unit 22 is for detecting the position and coordinates of the part pressed by the user on the liquid crystal display unit 21. The detected coordinates using the touch panel unit 22 are compared with the positions and coordinates of various keys shown on the liquid crystal display unit 21, and the key selected by pressing by the user is specified.

  The user can input various settings of the function of the multifunction peripheral 100 by pressing a key displayed on the liquid crystal display unit 21. Further, the user can register the address information (for example, FAX number, IP address, etc.) of the other party, the destination name, and the like as destination information using the liquid crystal display unit 21 and the touch panel unit 22.

  In addition, the operation panel 2 is provided with, for example, a numeric keypad 23 for inputting numbers and a start key 24 for instructing to start copying or transmitting after various settings. In addition, as hard keys, there are a copy key 25 (see FIG. 3) that is pressed when using the copy function, a send key 26 (see FIG. 3) that is pressed when using the scanner function, and the FAX function. Provided.

  Next, the document cover 101 has a fulcrum on the top surface and the back surface of the multifunction peripheral 100 and can be opened and closed so as to swing up and down. The document cover 101 presses the document placed on the placement reading contact glass 31 when the document is copied. The image reading unit 3 reads a document and forms image data of the document. The image reading unit 3 is provided with optical system members (not shown) such as an exposure lamp, a mirror, a lens, and an image sensor (for example, CCD). Instead of the document cover 101, a document conveying device that automatically and continuously feeds the documents one by one toward the reading position of the image reading section 3 (feed reading contact glass 32) may be provided.

  Then, using these optical system members, the document placed on the placement reading contact glass 31 is irradiated with light, and the output value of each pixel of the image sensor receiving the reflected light of the document is A / D converted. Then, image data is generated. The multifunction peripheral 100 can perform FAX transmission (FAX function), printing, and the like (copy function) based on image data obtained by reading.

  The paper feed unit 4a accommodates a plurality of sheets (for example, various sheets such as copy sheets, recycled sheets, thick sheets, and OHP sheets) and sends them one by one to the conveyance path 4b. The paper feed unit 4a includes a cassette 41 on which stored paper is placed (in FIG. 2, the upper one is given 41A and the lower one is given 41B). In addition, a feed roller 42 that is rotationally driven to feed the cassette 41 from the cassette 41 to the transport path 4b is provided (in FIG. 2, reference is made to the upper one by 42A and the lower one by 42B). For example, at the time of printing, the paper feed roller 42 is driven to rotate, and the sheets required for printing are sent out one by one to the conveyance path 4b.

  The transport path 4b is a path for transporting the paper from the paper feed unit 4a. An image forming unit 5a, a fixing unit 5b, and the like are arranged on the conveyance path. In the conveyance path 4b, a guide for guiding the paper, a pair of conveyance rollers 44 that are rotationally driven during the conveyance of the sheet, and the conveyed sheet are made to wait in front of the image forming unit 5a to form a toner image. A registration roller pair 45 and the like for feeding paper at the same timing are provided.

  The image forming unit 5a forms a toner image based on the image data, and transfers the toner image onto the conveyed paper. Therefore, the image forming unit 5a includes a photosensitive drum 51 supported so as to be rotationally driven in the direction of an arrow shown in FIG. 2, and a charging device 52, an exposure device 53, and a developing device disposed around the photosensitive drum 51. A device 54, a transfer roller 55, a cleaning device 56, and the like are provided.

  The toner image formation and transfer process will be described. The photosensitive drum 51 that is rotationally driven in a predetermined direction is provided substantially at the center of the image forming portion 5a. The charging device 52 charges the photosensitive drum 51 to a predetermined potential. The exposure device 53 outputs laser light based on the image data, scans and exposes the surface of the photosensitive drum 51, and forms an electrostatic latent image according to the image data. As the image data, image data obtained by the image reading unit 3, image data received from the counterpart device (the multifunction device 100 or the G3 FAX device 300) via the IP network 200, and the like are used.

  The developing device 54 supplies toner to the electrostatic latent image formed on the photosensitive drum 51 and develops it. The transfer roller 55 provided on the left side of the photosensitive drum 51 is pressed against the photosensitive drum 51 to form a nip. The sheet enters the nip while being timed according to the toner image. When the sheet enters, a predetermined voltage is applied to the transfer roller 55, and the toner image on the photosensitive drum 51 is transferred to the sheet. The cleaning device 56 removes the toner remaining on the photosensitive drum 51 after the transfer.

  The fixing unit 5b fixes the toner image transferred to the paper. The fixing unit 5b in the present embodiment is mainly composed of a heating roller 57 and a pressure roller 58 that incorporate a heating element. The heating roller 57 and the pressure roller 58 are in pressure contact to form a nip. Then, as the sheet passes through the nip, the toner on the sheet surface is melted and heated, and the toner image is fixed on the sheet. The paper after toner fixing is discharged to the discharge tray 43. In this way, image formation (printing) is performed when the copy function and printer function are used.

  The discharge conveyance unit 4c conveys the printed paper toward the discharge tray 43. The discharge transport unit 4c includes a discharge roller pair 46 that is driven to rotate in the forward rotation direction and is sent in the direction of the discharge tray 43. The discharge roller pair 46 may be rotated in reverse to perform double-sided printing (switchback).

(Hardware configuration of MFP 100)
Next, an example of a hardware configuration of the multifunction peripheral 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram illustrating an example of a hardware configuration of the multifunction peripheral 100 according to the embodiment of the present invention.

  First, the main body side of the multifunction device 100 will be described. A main control unit 6 is provided in the multifunction peripheral 100 main body. The main control unit 6 is connected to, for example, the operation panel 2, the image reading unit 3, the paper feeding unit 4a, the conveyance path 4b, the image forming unit 5a, the fixing unit 5b, the discharge conveyance unit 4c, and controls these.

  The main control unit 6 includes, for example, processing elements such as the CPU 61. The CPU 61 controls each part of the multifunction peripheral 100 by performing calculations based on a control program stored in the storage unit 7 and developed. The main control unit 6 includes a main control unit that performs overall control and image processing, an engine control unit that controls printing by performing ON / OFF of a motor that rotates an image forming and various rotating bodies, and the like. A plurality of types may be provided. In this description, a form in which these control units are combined as the main control unit 6 will be shown and described.

  The storage unit 7 is connected to the main control unit 6. The storage unit 7 is configured by combining nonvolatile and volatile storage devices such as ROM, RAM, and HDD. The storage unit 7 can store various data such as a control program, control data, setting data, and image data of the multifunction peripheral 100. The storage unit 7 (the HDD) stores one or a plurality of pieces of transmission destination information including address information, destination names, and the like of a partner apparatus for FAX communication.

  The main control unit 6 is connected to the communication unit 1. The communication unit 1 also includes an element such as a CPU that stores data such as a CPU, a chip, a driver, a protocol, and a program for network connection and communication with the other party. The communication unit 1 is provided as a single substrate, such as a network interface card. The communication unit 1 is connected to the IP network 200. As a result, the communication unit 1 is communicably connected to the G3 FAX apparatus 300 via the partner apparatus (the partner MFP 100A or the network compatible FAX apparatus 500) or the gateway 400. The communication unit 1 can transmit the image data obtained by the image reading unit 3 to the MFP 100, the network compatible FAX device 500, or the G3 FAX device 300 via the IP network 200 (network FAX function).

  The communication unit 1 can be communicably connected to a computer 600 (for example, a personal computer or a server) via a LAN or the like. The communication unit 1 can transmit, for example, image data obtained by the image reading unit 3 to the computer 600 (scanner function). It is also possible to perform printing based on image data transmitted from the computer 600 and received by the communication unit 1, or to perform FAX transmission to the MFP 100, the network compatible FAX apparatus 500, or the G3 FAX apparatus 300 (printer function, network FAX). function).

  Further, the communication unit 1 may be capable of transmitting and receiving image data and the like with the G3 FAX apparatus 300 through the conventional public telephone line without using the IP network 200. In this case, the communication unit 1 includes, for example, a telephone line connector and a FAX modem.

  Further, the main control unit 6 recognizes an input made on the operation panel 2 and controls the multifunction peripheral 100 so that copying or the like is performed in accordance with the setting of the user. Further, for example, the main control unit 6 is provided with an image processing unit 62 that performs image processing on image data obtained by reading a document by the image reading unit 3 and image data received by the communication unit 1. For example, the image processing unit 62 performs various types of image processing such as rotation, enlargement / reduction, density conversion, page number insertion, edge enhancement, and smoothing. The image processing unit 62 operates according to the function set on the operation panel 2. Since the image processing unit 62 can perform many image processes, it is assumed that known image processing can be performed, and details of the image processing performed by the image processing unit 62 are omitted.

  The image data processed by the image processing unit 62 is transmitted to, for example, the exposure device 53 and used for scanning / exposure of the photosensitive drum 51. When performing FAX transmission, the image processing unit 62 processes the image data for FAX transmission, and delivers the processed data to the communication unit 1.

  Next, the operation panel 2 includes a display control unit 20, a memory 27, a liquid crystal display unit 21, a touch panel unit 22, and various hard keys. The display control unit 20 includes a CPU, an IC, and the like, and controls the display on the liquid crystal display unit 21. Further, the display control unit 20 receives the output of the touch panel unit 22 and specifies the coordinates pressed on the liquid crystal display unit 21. Data such as a table indicating correspondence between the output of the touch panel unit 22 and coordinates is stored in the memory 27, for example. The display control unit 20 identifies and recognizes the key selected (pressed) on the setting screen by comparing the coordinates of the pressed position with the image data of each setting screen.

  For example, the screen and image data displayed on the liquid crystal display unit 21 are stored in, for example, the memory 27 in the operation panel 2. Therefore, the display control unit 20 reads the image data of the screen to be displayed next from the memory 27 every time a setting item selection screen or a key or button in each setting screen is pressed.

(Registration to destination information)
Next, an example of registration of transmission destination information in the MFP 100 according to the embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is an explanatory diagram illustrating an example of the transmission destination information registration screen S1 according to the embodiment. FIG. 5 is an explanatory diagram illustrating an example of the address book screen S2 in the multifunction peripheral 100 according to the embodiment.

  The MFP 100 according to the present embodiment can perform FAX transmission. At this time, it is necessary to specify a transmission destination (destination). The storage unit 7 of the MFP 100 according to the present embodiment does not need to input address information (for example, a destination address such as a FAX number or an IP address) each time transmission is performed. And address information) are stored as an address book.

  The user registers destination information in the storage unit 7 in advance using the operation panel 2. FIG. 4 is an example of a transmission destination information registration screen S1 which is a screen for registration and input of transmission destination information.

  When a specific operation is performed on the operation panel 2, the liquid crystal display unit 21 displays a transmission destination information registration screen S1. When the new key K1 arranged on the transmission destination information registration screen S1 is pressed, new (different) transmission destination information can be registered. When the registration key K2 is pressed, the setting and input contents are stored in the storage unit 7.

  As items that can be registered as destination information, for example, items such as a destination name, reading, number (serial number), FAX number, SMB, FTP, mail address, and network FAX are prepared. It should be noted that other items may be registered. When the change keys K3 to K10 arranged on the right side of each item are pressed, the liquid crystal display unit 21 displays a software keyboard screen (not shown) for character input, and the touch panel unit 22 or the like displays each item for the software keyboard screen. Accept input for. For example, it is possible to input alphabets, symbols, kanji, hiragana, katakana, and the like. The input to each item can also be performed using the numeric keypad 23. The input result is displayed below each item name. For example, the user presses the change key K10 of the network FAX item, and inputs and registers the destination address (for example, IP address) of the other party on the network FAX.

  The liquid crystal display unit 21 displays each destination information registered in advance as an address book. For example, the display control unit 20 acquires transmission destination information such as a destination name and address information from the storage unit 7 via the main control unit 6. Then, the display control unit 20 causes the liquid crystal display unit 21 to display transmission destination information such as address information.

  Specifically, FIG. 5 shows an example of the address book screen S2. For example, when the transmission key 26 is pressed, the liquid crystal display unit 21 displays an address book screen S2 as shown in FIG. The liquid crystal display unit 21 displays the destination information stored in the storage unit 7 as a list on the address book screen S2.

  The destination information such as address information is displayed in the list display area F1 of the address book screen S2. The storage unit 7 of the MFP 100 according to the present embodiment can store thousands of pieces of transmission destination information at least for each destination name. Therefore, there are cases where the destination information cannot be displayed in the list display area F1. Therefore, a scroll bar B1 is provided on the right side of the list display area F1. When the scroll bar B1 is pressed, the liquid crystal display unit 21 switches transmission destination information such as address information displayed in the list display area F1.

  Then, below the list display area F1, a first narrowing key group KG1 for narrowing down transmission destination information by an initial of the destination name is provided. The first narrowing key group KG1 includes a key for narrowing down the destination name with initials (a key in which the first character of each line is written in hiragana), and a key for narrowing down the initials of the destination name in alphabetical units for a plurality of characters. Etc. In addition, a second narrowing key group KG2 for narrowing down by a registered transmission method is also provided. The second narrowing key group KG2 includes keys for narrowing down by a transmission method such as FAX or E-mail. The display control unit 20 narrows down the destination information using the pressed down key as a narrowing condition, and causes the liquid crystal display unit 21 to display the destination information after narrowing down.

  Of the destination information displayed in a list, one to be transmitted is selected (for example, a check box is checked for the selected destination information), and the destination is set when the OK key K11 is pressed. . For example, the display control unit 20 transmits data indicating the selected transmission destination information to the main control unit 6, and the main control unit 6 recognizes the transmission destination. For example, when the start key 24 of the operation panel 2 is pressed, that fact is transmitted from the operation panel 2 to the main control unit 6, and the main control unit 6 causes the communication unit 1 to perform FAX transmission, for example.

(Flow of facsimile communication in MFP 100)
Next, an example of a flow of FAX transmission in the multifunction machine 100 of this embodiment will be described using FIG. FIG. 6 is an explanatory diagram illustrating an example of a sequence at the time of FAX communication via the network in the MFP 100 according to the present embodiment. In the following, between the MFP 100 (the communication unit 1 thereof) and the counterpart device (the counterpart MFP 100A, the network compatible FAX device 500, etc.), the ITU-T. In accordance with the 38 standard, communication (exchange) of packetized signals and data is performed using UDP as a transport.

  When the MFP 100 starts communication with the counterpart device for network image transmission for image data transmission, the communication unit 1 notifies the counterpart device of the start of FAX communication with the counterpart device, so that CNG (Calling Tone) (Call).

  The counterpart device that has received the CNG returns CED (Called Station Identification). Further, the counterpart device returns a DIS (Digital Identification Signal) and notifies the capability. In addition, the communication unit 1 of the multifunction peripheral 100 transmits a DCS (Digital Command Signal) to the counterpart device, and instructs the FAX communication mode.

  The counterpart apparatus that has received the DCS returns CFR (Confirmation to Receive) and notifies that reception preparation is complete. Thereafter, the communication unit 1 of the MFP 100 transmits the image data. If the received data is good, the counterpart device returns an MCF (Message Confirmation) as an image data communication result to the multi-function device 100 to notify that it has been received normally. As a result, the FAX communication is normally completed, and the communication unit 1 of the MFP 100 on the transmission side transmits DCN (Disconnect) to the counterpart device and disconnects the line.

  When there is a communication error, the line may be disconnected before the FAX communication is completed (for example, before receiving the MCF from the counterpart device).

  Unlike the above, the communication unit 1 of the MFP 100 may transmit the image data after establishing a session with the counterpart device based on SIP (Session Initiation Protocol).

(Redundant packet)
Next, a UDP packet 8 including a redundant packet in FAX transmission via the network in the MFP 100 according to the present embodiment will be described with reference to FIG. FIG. 7 is an explanatory diagram illustrating an example of the structure of the UDP packet 8 including the redundant packet in the multifunction peripheral 100 according to the present embodiment. In the example of FIG. 7, the number of redundant packets is four (redundancy is 4).

  In the MFP 100 of this embodiment, the communication unit 1 performs FAX communication using UDP as a transport by the exchange shown in FIG. Then, the communication unit 1 performs transmission by attaching a redundant packet to each UDP packet.

  In the UDP packet in the FAX communication of this embodiment, the main message is set first. When the packet redundancy number is 4, up to four previous packets transmitted as the main message are attached as redundant packets.

  The example of FIG. 7 shows an example in which the main message with the serial number 20 is set first, and then the packets with the serial numbers 16, 17, 18, and 19 are set as redundant packets as redundant packets. In the next packet transmission, the main message with the serial number 21 is set first, and the packets with the serial numbers 17, 18, 19, and 20 are set as redundant packets. Thereafter, the process is repeated until the FAX transmission ends.

  As described above, by attaching a redundant packet, even if the main message has an error and is discarded, the error can be recovered by checking the redundant packet attached in the next packet transmission.

(Storing and updating the packet redundancy number for each destination)
Next, storage of the packet redundancy number and update of the packet redundancy number for each transmission destination information in the MFP 100 according to the present embodiment will be described with reference to FIGS. FIG. 8 is a schematic diagram illustrating an example of the concept of transmission destination information stored in the storage unit 7 of the present embodiment. FIG. 9 is a flowchart illustrating an example of the flow of updating the packet redundancy number in the multifunction peripheral 100 according to the present embodiment.

  As shown in FIG. 8, transmission destination information is stored (registered) in a partial area of the storage unit 7. The destination information is classified for each serial number (for each case). For example, one destination name is assigned to each serial number, and address information (FAX number, IP address, etc.) and the packet redundancy number are stored in association with one destination name. Further, as shown in FIG. 8, one transmission destination information includes a value that determines the packet redundancy number together with the address information, and the storage unit 7 stores one packet redundancy number for one transmission destination information. Is stored (registered).

  The communication unit 1 performs communication with the redundant number of packets stored in the storage unit 7 for each destination when performing FAX communication using UDP. For example, at the time of FAX transmission using UDP, when a destination is set on the address book screen S2 or the like, the redundant number of packets in FAX communication is also set. Although details will be described later, the packet redundancy number may be updated when the FAX transmission job ends. When a new destination name is registered and one piece of transmission destination information is added, for example, an integer from 1 to 5 is automatically entered as the packet redundancy number as a default.

  When the communication unit 1 of the MFP 100 performs FAX transmission using the UDP via the IP network 200, the communication unit 1 refers to the packet redundancy number associated with the address information as a part of the transmission destination information, and stores it in the storage unit 7. The UDP packet 8 is transmitted with a predetermined packet redundancy number. Further, when the communication unit 1 performs FAX reception via the IP network 200, if the address information notified from the counterpart device is stored (registered) in the storage unit 7, the packet redundancy associated with the address information is performed. It exchanges signals with the other party device by number. If the address information of the counterpart device is not registered in the storage unit 7, the communication unit 1 sets the predetermined packet redundancy number (for example, an arbitrary value of 1 to 5) or the packet redundancy number of the counterpart device. In addition, exchange (FAX communication) with the counterpart device is performed.

  Next, an example of the flow of updating the packet redundancy number based on the communication result will be described with reference to FIG. The flowchart of FIG. 9 is started when, for example, FAX communication using the UDP with the counterpart device is completed. Therefore, the start of FIG. 9 is a point in time when the transmission or reception of the FAX via the network is finished using UDP. Note that the packet redundancy number is updated with respect to the counterpart device in which the transmission destination information is registered.

  At this time, the main control unit 6 stores (stores) communication history data indicating the FAX communication result in the storage unit 7 (step # 1). As shown in FIG. 8, a storage area for storing a communication history as a part of each destination information may be provided as a storage location of the communication history.

  The main control unit 6 causes the storage unit 7 to store success or failure of FAX communication as communication history data. When the FAX communication fails (when there is a communication error), the main control unit 6 stores the content of the communication error in the storage unit 7 as communication history data. For example, when the communication line is interrupted during communication, the main control unit 6 leaves the fact that the line is interrupted as communication history data. For example, when there is no response from the other party during communication and a timeout occurs, the main control unit 6 leaves the occurrence of the timeout as communication history data. For example, when the counterpart device is not found (for example, the main power supply of the counterpart device is turned off, etc.), the main control unit 6 leaves the fact that the counterpart device cannot be found as communication history data. For example, when the counterpart device is busy during communication, the main control unit 6 leaves a message indicating that the connection has failed as communication history data. Note that what communication errors are left as communication history data is determined in advance.

  For example, when the multifunction device 100 is on the transmission side, the data received by the counterpart device is missing, and when the RTN signal (Retrain Negative) is received as a signal indicating communication failure from the counterpart device, the main control unit 6 The fact that the RTN signal has been received as communication history data may be stored in the storage unit 7. On the other hand, when the multifunction device 100 is the receiving side, the data received from the counterpart device is missing, and when the RTN signal is transmitted as a signal indicating communication failure, the main control unit 6 transmits the RTN signal as communication history data. You may memorize | store in the memory | storage part 7.

  In addition to the RTN signal, an application that verifies the data received from the counterpart device and ensures the reliability is installed in the storage unit 7 in the multi-function device 100, and the main control unit 6 is based on the application and the counterpart device Recognize that there is a part of data received from cannot be recovered. At this time, the communication unit 1 issues a signal indicating communication failure due to a packet error to the counterpart device. And the main control part 6 may memorize | store in the memory | storage part 7 as communication log | history data of a communication error that the signal which shows the communication failure by a packet error from the communication part 1 was transmitted to the other party apparatus.

  Also, the partner device (for example, the MFP 100) may be equipped with an application that verifies the received data to ensure reliability, and there is a portion that cannot be recovered from the data received by the partner device. , The counterpart device may send a signal indicating a communication failure due to a packet error to the communication partner such as the multifunction device 100. And the main control part 6 may memorize | store in the memory | storage part 7 as communication history data of a communication error that the communication part 1 received the signal which shows the communication failure by the packet error emitted from the other party apparatus.

  Then, the main control unit 6 confirms whether or not the communication is completed without communication error (whether the communication is successful) in the communication with the other party whose communication has been completed (step # 2).

  If the communication is successful (if there is no communication error, step # 2 is Yes), the main control unit 6 checks whether or not the packet redundancy number of the partner whose communication has ended is the minimum value (step #). 3). For example, the minimum value is set to “1”. The minimum value may be a fixed value determined by the manufacturer of the multifunction machine 100 or may be set by the user on the operation panel 2. And the memory | storage part 7 has memorize | stored the value of the minimum value.

  If it is the minimum value (Yes in step # 3), there is no need to further reduce the packet redundancy number, so the main control unit 6 does not update the packet redundancy number of the other party that has finished communication, Control ends (END). On the other hand, if it is not the minimum value (No in Step # 3), the main control unit 6 causes the storage unit 7 to update and store a value obtained by subtracting 1 from the current packet redundancy number of the other party that has finished communication (update in a decreasing direction). Step # 4). For example, if the current packet redundancy number is “3”, the storage unit 7 stores “2” as a new packet redundancy number. And this control is complete | finished (end).

  On the other hand, when the communication fails (No in Step # 2), the main control unit 6 confirms the communication history data of the other party that has finished the communication (Step # 5). Then, main controller 6 confirms whether or not there is an error relating to packet transmission / reception (step # 6). In other words, the main control unit 6 confirms whether or not the packet is lost during communication and the packet transmission / reception is not performed correctly.

  For example, when the multifunction device 100 is the transmission side, the main control unit 6 confirms communication history data, and if the communication unit 1 receives an RTN signal, the main control unit 6 transmits and receives packets by FAX communication. It may be recognized that there was an error regarding. Alternatively, if the communication unit 1 receives a signal indicating that there is a portion that cannot be recovered from the received data (a signal indicating a packet error) from the counterpart device, the main control unit 6 relates to packet transmission / reception by FAX communication. You may recognize that there was an error.

  When the multi-function device 100 is on the receiving side, the main control unit 6 confirms communication history data. If the communication unit 1 transmits an RTN signal, the main control unit 6 transmits and receives packets by FAX communication. It may be recognized that there was an error regarding. Alternatively, if the communication unit 1 transmits a signal indicating that there is a portion that cannot be recovered from the data received by the communication unit 1 (a signal indicating a packet error) to the counterpart device, the main control unit 6 may You may recognize that there was an error related to packet transmission and reception in communication.

  In addition, for example, when a timeout occurs, it may be handled as an error related to packet transmission / reception. It is possible to arbitrarily determine what kind of error is determined as an error related to packet transmission / reception.

  If there is no error related to packet transmission / reception (No in step # 6), the main control unit 6 ends the control without updating the packet redundancy number in the storage unit 7 (end). As long as a communication error has occurred, the possibility of a communication error being triggered by an error due to packet transmission / reception is not zero, so the packet redundancy number is not updated and is left as it is.

  On the other hand, if the error is related to packet transmission / reception, the main control unit 6 confirms whether or not the packet redundancy number of the other end of communication is the maximum value (step # 7). For example, the maximum value is set to a value of “5 to 10”. Note that the maximum value may be a fixed value determined by the manufacturer of the multifunction device 100 or may be set by the user on the operation panel 2. And the memory | storage part 7 has memorize | stored the value of the maximum value. Thereby, it is possible to prevent the packet redundancy number from increasing abnormally.

  If it is the maximum value (Yes in step # 7), the main control unit 6 ends this control without updating the packet redundancy number of the other party that has finished communication (end). On the other hand, if it is not the maximum value (No in step # 7), the main control unit 6 causes the storage unit 7 to update and store a value obtained by adding 1 to the current packet redundancy number of the other end of communication (update in the increasing direction). Step # 8). For example, if the current packet redundancy number is “3”, the storage unit 7 stores “4” as a new packet redundancy number. And this control is complete | finished (end).

  In this way, the communication device (for example, the multifunction device 100) according to the present invention communicates with a counterpart device (such as the counterpart multifunction device 100A) using UDP as a transport via the network, The storage unit 7 stores the address information of each counterpart device and the packet redundancy number in the UDP communication in association with the address information. The storage unit 7 has an error in communication with the counterpart device that has finished communication after the communication is completed. If there is, there is an update in the direction to increase the packet redundancy number of the counterpart device that has finished communication, and if there is no error, the update is made in a direction to reduce the packet redundancy number of the counterpart device that has finished communication. Communicates with the counterpart device using the packet redundancy number stored in.

  Thereby, the optimal number of packet redundancy can be determined for each destination. In addition, after the communication is completed (after the communication job), only the communication result is confirmed and the packet redundancy number is updated. Therefore, in order to determine the packet redundancy number during communication, the communication status confirmation process and the packet redundancy number change process are performed multiple times. The processing load on the communication apparatus (for example, the multifunction peripheral 100) is reduced. Therefore, based on simple processing, communication can be performed with the optimum number of packet redundancy for each destination, and data can be reliably transmitted while minimizing the time required for transmission to the counterpart device (the counterpart MFP 100A, etc.). Can be sent.

  Specifically, if the error in communication with the counterpart device (the counterpart MFP 100A or the like) is an error related to packet transmission / reception, the storage unit 7 updates the packet redundancy number to increase after the communication ends, If the error is not related to packet transmission / reception, the packet redundancy number is not updated after the communication is completed. As a result, when there is data loss that cannot be recovered by communication with the counterpart device and the packet redundancy number should be increased, the packet redundancy number is updated so that the packet redundancy number is increased from the next transmission. Therefore, the reliability of communication using UDP can be improved for each destination.

  Further, as the number of packet redundancy increases, the effect of improving the reliability can be expected. However, on the other hand, the time required for the end of communication becomes longer. In the present embodiment, when the packet redundancy number before update is a predetermined maximum value, the storage unit 7 does not update the packet redundancy number to a value larger than the maximum value. Thereby, the upper limit of the packet redundancy number can be set and the packet redundancy number can be prevented from becoming abnormally long.

  In addition, the effect of shortening the time from the start to the end of communication can be expected as the number of packet redundancy decreases, but on the other hand, recovery may be difficult when there is data loss in the communication path. In the present embodiment, when the packet redundancy number before update is a predetermined minimum value, the storage unit 7 does not update the packet redundancy number to a value smaller than the minimum value. Thereby, the lower limit of the packet redundancy number can be set, and the minimum reliability can be ensured.

  In addition, the storage unit 7 increases or decreases the packet redundancy number by one. As a result, the packet redundancy number can be brought close to the optimum value.

  Further, the present invention can be regarded as a communication system 10 that is a combination of a communication device (for example, a multifunction device 100) and a counterpart device (such as a counterpart multifunction device 100A). Specifically, the communication system 10 includes a communication unit 1 that communicates with a counterpart device using UDP as a transport via a network, address information of each counterpart device, and UDP associated with the address information. The storage unit 7 stores the packet redundancy number in communication. If there is an error in communication with the counterpart device after the communication ends, the storage unit 7 tends to increase the packet redundancy number of the counterpart device in the communication job. If there is no error, the update is performed in a direction to reduce the packet redundancy number of the counterpart device that has performed communication, and the communication unit 1 communicates with the counterpart device using the packet redundancy number stored in the storage unit 7. Transmits a signal indicating that packet reception has failed as a communication error to the communication unit 1. As a result, the same effect as described above can be obtained, and the communication apparatus can determine the optimum number of packet redundancy for each destination.

  Next, another embodiment will be described. In the above description, an example in which the MFP 100 performs FAX transmission / reception using the UDP via the IP network 200 has been described, but instead of the MFP 100, a FAX dedicated device may be used.

  In the above description, the example in which the destination information including the packet redundancy number is stored in the storage unit 7 has been described. However, the destination information including the packet redundancy number may be stored in the memory 27 of the operation panel 2. Then, the main control unit 6 and the display control unit 20 may cause the memory 27 of the operation panel 2 to update the packet redundancy number according to the communication result.

  Although the embodiment of the present invention has been described, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  The present invention is applicable to a communication apparatus such as a facsimile apparatus.

1 Communication Unit 7 Storage Unit 10 Communication System 100 Multifunction Device (Communication Device)
100A Counterpart MFP (partner device)
200 IP network (network)
300 G3 FAX machine (counter machine)
500 FAX machine (counter machine)

Claims (6)

A communication unit that communicates with a counterpart device using UDP as a transport via a network;
A storage unit that stores the address information of each counterpart device and the packet redundancy number in UDP communication for each destination in association with the address information;
The communication unit refers to the packet redundancy number associated with the address information, communicates with the counterpart device using the packet redundancy number determined in the storage unit,
After the communication is completed, the storage unit updates the packet redundancy used in communication with the partner device that has finished communication if there is an error in communication with the partner device that has finished communication, and if there is no error. A communication apparatus , wherein the packet redundancy number is determined for each destination by updating in a direction to reduce the packet redundancy number used in communication with a partner apparatus that has finished communication. If the error in communication with the counterpart device is an error related to packet transmission / reception, the storage unit updates the packet redundancy number used in communication with the counterpart device that has finished communication after the communication is finished. 2. The communication apparatus according to claim 1, wherein if the error is not related to packet transmission / reception, the packet redundancy number used in communication with the partner apparatus that has ended communication is not updated after the communication ends.   3. The storage unit according to claim 1, wherein when the packet redundancy number before update is a predetermined maximum value, the storage unit does not update the packet redundancy number to a value larger than the maximum value. Communication equipment.   The storage unit does not update the packet redundancy number to a value smaller than the minimum value when the packet redundancy number before update is a predetermined minimum value. The communication device according to any one of 1 to 3.   5. The communication apparatus according to claim 1, wherein the storage unit increases or decreases the packet redundancy number by one. The communication apparatus includes a communication device and a counterpart device, the communication device communicating with the counterpart device using UDP as a transport via a network, address information of each counterpart device, and a destination associated with the address information. Each having a storage unit for storing the packet redundancy number in UDP communication, the communication unit refers to the packet redundancy number associated with the address information, and the packet redundancy number determined in the storage unit In the communication with the counterpart device, after the end of communication, if there is an error in communication with the counterpart device , the storage unit is updated in the direction to increase the number of packet redundancy used in communication with the counterpart device in the communication job, if there are no errors, constant the packet number of redundant update in the direction of reducing the number of packets redundancy used in the communication with the partner device communicates each one destination ,
The counterpart apparatus transmits a signal indicating that packet reception has failed as a communication error to the communication unit.