JP4154259B2 - Method for correcting synchronization deviation of facsimile signal receiving apparatus and apparatus for executing the method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for correcting synchronization deviation of a facsimile signal receiving apparatus connected to an IP (Internet Protocol) network, and an apparatus for executing this method.
[0002]
[Prior art]
Conventionally, as a device that transmits and receives a facsimile signal via an IP network, for example, there is a facsimile apparatus described in Patent Document 1 below.
[0003]
When this facsimile apparatus transmits a facsimile signal, the facsimile signal is packetized and then sent to the destination facsimile apparatus via the IP network. The destination facsimile machine decomposes the packet data sent via the IP network, and then decodes the facsimile signal obtained by the decomposition.
[0004]
As described above, in a device that transmits and receives a packet signal via an IP network, a reception buffer is provided in order to suppress a synchronization shift with the counterpart device.
[0005]
With such a reception buffer, even if a synchronization shift including a clock shift occurs, a synchronization shift corresponding to the buffer capacity can be absorbed.
[0006]
[Patent Document 1]
JP 2002-101256 A
[0007]
[Problems to be solved by the invention]
However, in the prior art, when high-quality or large-capacity facsimile data is sent, it takes a long time to receive the data. Therefore, accumulation of synchronization deviation increases during this time, and this synchronization deviation amount exceeds the buffer capacity. Therefore, there is a problem that part of the image information may be lost.
[0008]
Therefore, if the buffer capacity is increased, the above problems can be solved. However, in the processing after the buffer, a data delay corresponding to the buffer capacity occurs, so a control procedure timeout may occur. There is a problem of causing trouble.
[0009]
The present invention has been made paying attention to the conventional problems as described above, and a method of correcting a synchronization shift of a facsimile signal receiving apparatus capable of suppressing a loss of image information as much as possible while suppressing occurrence of a control procedure timeout. And an apparatus for performing the method.
[0010]
[Means for Solving the Problems]
  A method for correcting a synchronization shift of a facsimile signal receiving apparatus for correcting a synchronization shift with a facsimile signal transmitting apparatus for achieving the above-described object,
  A non-signal detecting step of detecting a non-signal inserted between a facsimile control signal and a facsimile image information signal of a predetermined page and a facsimile control signal and a facsimile image information signal of the next page among the facsimile signals;
  A synchronization shift detection step of detecting an amount of the synchronization shift from when the facsimile control signal is received until the non-signal is detected when the facsimile signal is received from the facsimile signal transmitting device;
  According to the amount of synchronization deviation detected in the synchronization deviation detection step during the period of no signal., ReceivedA buffer data increase / decrease step for deleting the no signal data in the communication buffer or inserting the no signal data in the reception buffer;
  It is characterized by including.
[0011]
Here, in the synchronization shift detection step, a synchronization shift amount during a period in which at least the facsimile image information signal is received among the facsimile signals is stored, and in the buffer data increase / decrease step, the synchronization shift amount is stored. The no-signal data corresponding to the amount may be deleted or inserted from the reception buffer.
[0012]
  Further, a facsimile signal receiving apparatus for achieving the above-mentioned object is as follows:
  Encoding andA reception buffer for temporarily storing data indicated by the facsimile signal after decomposing the packetized facsimile signal and before decoding the data;
  Of the facsimile signal, a predetermined pageFacsimile control signal andFacsimile image information signal and,On the next pageFacsimile control signal andBetween the facsimile image information signal,No signal detection means for detecting no signal inserted;
  When receiving the facsimile signal from the facsimile signal transmitting device,The synchronization deviation between the reception of the facsimile control signal and the detection of the no signal is not found.Synchronization deviation detecting means for detecting the amount;
  During the period in which the no-signal detection means detects the no-signal, the no-signal data in the reception buffer is detected according to the amount of synchronization deviation detected by the synchronization deviation detection means.RemoveOr no signal in the reception bufferofIn-buffer data increase / decrease means for inserting data,
  It is characterized by having.
[0013]
Here, the synchronization shift detection means includes synchronization shift amount storage means for storing a synchronization shift amount during a period in which at least the facsimile image information signal is received among the facsimile signals, and the buffer data increase / decrease means. May delete or insert the no-signal data corresponding to the synchronization shift amount stored in the synchronization shift amount storage means from the reception buffer.
[0014]
The in-buffer data increasing / decreasing means preferably deletes or inserts the no-signal data from the reception buffer during a no-signal period and after a predetermined time elapses from the start of the no-signal period.
[0015]
Further, the above facsimile signal receiving apparatus may include buffer capacity changing means for changing the capacity of the reception buffer. In this case, the buffer capacity changing means may change the buffer capacity in accordance with an instruction from the outside, or may change the buffer capacity when the decoding means decodes the received signal as a facsimile signal.
[0016]
The invention relating to the above facsimile signal receiving apparatus may be applied to any apparatus as long as it receives a packetized facsimile signal and decomposes it, for example, an IP gateway, an IP exchange, You may apply to an IP facsimile machine.
[0017]
Specifically, the IP gateway
Any of the above facsimile signal receiving devices;
Packetizing means for packetizing various data;
Transmitting means for sending data packetized by the packetizing means to the IP network;
It can comprise by providing.
[0018]
In addition, the IP switch
Any of the above facsimile signal receiving devices;
Packetizing means for packetizing various data;
Transmitting means for sending data packetized by the packetizing means to the IP network;
Call control means for performing call control between the transmission source and the reception destination;
It can comprise by providing.
[0019]
The IP facsimile machine
Any of the above facsimile signal receiving devices;
Image forming means for forming an image based on the data decoded by the decoding process;
It can comprise by providing.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, various embodiments of a facsimile signal receiving apparatus according to the present invention will be described with reference to the drawings.
[0021]
First, a first embodiment of a facsimile signal receiving apparatus will be described with reference to FIGS.
[0022]
The facsimile signal receiving apparatus of this embodiment is an IP gateway. Here, a communication system including this IP gateway will be described with reference to FIG.
[0023]
This communication system includes a plurality of routers 108 and 108a connected to an IP network 109, HUBs 107 and 107a connected to the routers 108 and 108a, and IPs connected to the HUBs 107 and 107a via LAN lines. Gateways 100 and 100 a, a computer 105 that changes various setting values of the IP gateway 100, private branch exchanges (PBXs) 103 and 103 a connected to the IP gateways 100 and 100 a, and the PBX 103 The computer 106 changes various setting values and the like, and a plurality of general telephones 101 and 101a and general facsimile apparatuses 102 and 102a connected to the PBXs 103 and 103a. The PBX 103 is further connected to a public switched telephone network (PSTN) 110.
[0024]
  As shown in FIG. 2, an IP gateway 100 as a facsimile signal receiving apparatus according to the present embodiment includes a PBX interface 111 that receives signals from a general telephone 101, a general facsimile apparatus 102, and the like from a PBX 103, and an IP network via a LAN line. Compresses and encodes audio signals, facsimile signals, etc. of signals received by the PBX interface 111 and decompresses the signals received by the Ethernet controller 112, and the Ethernet (registered trademark of Xerox Corporation) controller 112 connected to the It stores a DSP 113 for decoding and decoding, a card flash controller 114 for reading / writing data to / from a memory card storing various operation programs and various operation histories of the apparatus 100, and various operation programs of the apparatus 100. And EPROM115, a RAM116 which functions as a receiving buffer or a work memory, and a serial bus controller 117 for communicating with an external computer, for displaying various informationL ED118, a CPU 120 that performs various operations in accordance with an operation program stored in the EPROM 115, and the like, and a bus 119 that connects these components to each other.
[0025]
As shown in FIG. 3, this IP gateway functionally includes a packet signal reception processing unit 140 that processes packet signals from the IP network, and a packet signal transmission processing unit 130 that processes packet signals transmitted to the IP network. And has.
[0026]
As a functional part of the packet signal reception processing unit 140, the CPU 120 decomposes a packet signal from the IP network received by the reception unit 112b of the Ethernet controller 112, and stores the packet signal in the reception buffer 116b in the RAM 116. The data deciphering unit (no-signal detecting unit) 122 for deciphering what kind of data is obtained by the decomposing by the packet decomposing unit 121b, and the synchronization deviation from the packet signal received by the receiving unit 112b of the Ethernet controller 112. A synchronization shift detecting unit 123 for obtaining the amount, a buffer data increasing / decreasing unit 128 for increasing / decreasing data in the reception buffer 116b according to the synchronization shift amount detected by the synchronization shift detecting unit 123, and a buffer capacity for changing the capacity of the reception buffer 116b And a change unit 129. Further, the CPU 120 has a reference clock 127 for generating reference clock signals of various parts, and is encoded by the encoding part 113a of the DSP controller 113 as a functional part as the packet signal transmission processing part 130. A packetizing unit 121a that packetizes the signal and passes the signal to the transmitting unit 112a of the Ethernet controller 112 is provided.
[0027]
The synchronization shift detection unit 123 counts the number of packet signals every 10 s according to the clock signal from the reference clock 127, and the transmission side of these packet signals from the number of packets counted by the counter 124. After obtaining the transmission time, the difference between the transmission time and the actual reception time 10 s, that is, the measurement period / synchronization deviation detection unit 125 for obtaining the amount of synchronization deviation, and the synchronization deviation detected by the measurement period / synchronization deviation detection unit 125. A synchronization shift amount accumulation unit 126 for accumulating the amount.
[0028]
Next, an operation when the IP gateway 100 of the present embodiment receives a facsimile packet signal from the IP network 109 via the LAN line will be described.
[0029]
When the receiving unit 112b of the Ethernet controller 112 receives the packet signal from the LAN line, the packet decomposing unit 121b decomposes the packet signal and temporarily stores the data obtained as a result of the decomposing in the receiving buffer 116b. Further, the data decoding unit 122 determines whether the packet signal is a facsimile signal from the data obtained as a result of the decomposition. Specifically, it is determined whether or not it is a facsimile signal from the description content of the header part of the packet signal obtained by the decomposition of the packet signal. If the data decoding unit 122 determines that the received signal is a facsimile signal, the data decoding unit 122 sends a message to that effect to the synchronization shift detecting unit 123 and the buffer amount changing unit 129. The synchronization shift detection unit 123 is activated upon receiving this, and the buffer capacity changing unit 129 changes the capacity of the reception buffer 116b to a facsimile signal buffer capacity described later.
[0030]
  When the synchronization shift detection unit 123 is activated, the counter 124 of the synchronization shift detection unit 123 has a measurement period of n seconds 405 (shown in FIG. 4).1 secondThe number of received packet signals is counted at every interval. If the facsimile signal transmission side transmits one packet signal in 10 ms, if the IP network 109 is not fluctuated and there is no clock shift with the facsimile signal transmission side,1 Second100 packet signals are counted in between. However, in reality, the IP network 109 has fluctuations and there is also a clock shift with the facsimile signal transmission side.1 secondThe number of counts between them is, for example, 98 or 104. The measurement period synchronization deviation detection unit 125 of the synchronization deviation detection unit 123 receives the count number m of the packet signal from the counter 124 as shown in (Equation 1) below, and the packet signal transmission interval ( 10 ms) to determine the transmission time of these packet signals, and from this transmission time, the reception time1 second(1000 ms) is subtracted to determine the amount of synchronization deviation e during the measurement period (10 ms).
[0031]
      Measurement period synchronization amount e = (m × 10 ms) −1000 ms
  The measurement period / synchronization deviation detection unit 1251 secondEach time, the measurement period synchronization deviation amount e is obtained, and this value is stored in the synchronization deviation amount accumulation unit 126.
[0032]
As shown in FIG. 4, the facsimile packet signal 400 includes a facsimile control information signal 401 indicating data such as output paper size, a facsimile image information signal 402, and a non-signal 403 indicating page change. These signals are received in the order of the facsimile control information signal 401, the facsimile image information signal 402, and the no signal 403, and thereafter these signals are repeatedly received.
[0033]
The synchronization shift detection unit 123 detects the synchronization shift amount from the time when the first facsimile control information signal 401 is received, and keeps the synchronization shift amount storage unit 126 in each measurement period until the period of no signal 403 is started. The detected synchronization shift amount is sequentially accumulated.
[0034]
When the data decoding unit 122 detects no signal, the data increase / decrease unit 128 in the buffer notifies the buffer data increase / decrease unit 128 to that effect. The data increase / decrease unit 128 in the buffer receives no-signal data corresponding to the amount of synchronization deviation accumulated in the amount of synchronization deviation accumulation unit 126 after elapse of a predetermined period (Xms, here, 100 ms) 404 after receiving the notification b. The no-signal data corresponding to the amount of synchronization deviation is deleted from the reception buffer 116b or inserted into the reception buffer 116b.
[0035]
Specifically, for example, as shown in FIG. 4, when the synchronization deviation amount E accumulated in the synchronization deviation amount accumulation unit 126 is (+) 30 ms at the start of the period of the no-signal 403, the receiving side Since the transmission speed of the facsimile packet signal on the transmission side is fast and a synchronization shift of 30 ms has occurred from the start of detection, data for 30 ms, that is, three packets (= (30 ms ÷ 10 ms) of data is deleted from the reception buffer, and the synchronization shift including the clock shift is corrected. As described above, the deletion timing is the period of the no signal 403, and is after the elapse of the predetermined time 404 from the start of the no signal period. It is. Therefore, even if the data is deleted from the reception buffer 116b, there is no influence on the facsimile control information and the facsimile image information.
[0036]
Further, when the synchronization deviation amount E accumulated in the synchronization deviation amount accumulation unit 126 is (−) 30 ms, the transmission speed of the facsimile packet signal on the transmission side is slow with reference to the reception side, and the detection starts. Since a synchronization shift of 30 ms has occurred, data of 30 ms, that is, three non-signal data for the number of packets is inserted into the reception buffer 116b, and the synchronization shift including the clock shift is corrected.
[0037]
Note that the no-signal period is T.D. Since the minimum is 95 ms in the 30 recommendation, the predetermined time 404 from the start of the no-signal period is set to 100 ms here.
[0038]
In general, communication via the IP network 109 is affected by fine fluctuations on the order of several ms. For this reason, even if an attempt is made to detect a synchronization shift including a clock shift in the order of several ms, the influence of this fluctuation is so great that the synchronization shift cannot be detected. Therefore, in the present embodiment, by accumulating the synchronization deviation over a long period of receiving the facsimile signal for one page, the fine fluctuation is smoothed, and the influence of the fine fluctuation is eliminated. It detects and corrects synchronization gaps including clock gaps.
[0039]
When the data in the buffer increasing / decreasing unit 128 increases / decreases the data in the reception buffer 116b, the buffer data increasing / decreasing unit 128 immediately notifies the synchronization shift detecting unit 123 to that effect, and newly starts detecting the amount of synchronization shift. Thereafter, in the same manner as described above, the amount of synchronization deviation is corrected every time there is no signal period.
[0040]
The data stored in the reception buffer 116b is then decoded and decompressed by the decoding unit 113b of the DSP controller 113, and then transmitted from the transmission unit 111b of the PBX interface 111 to the destination facsimile apparatus 102 via the PBX 103. It is done.
[0041]
When a facsimile signal is transmitted from the facsimile apparatus 102, the facsimile signal is received by the receiving unit 111a of the PBX interface 111 of the IP gateway 100 via the PBX 103 and encoded by the encoding unit 113 of the DSP controller 113. And compressed. Thereafter, it is packetized by the packetization unit 121 and sent as a facsimile packet signal from the transmission unit 112a of the Ethernet controller 112 to the IP network 109.
[0042]
When the Ethernet controller 112 of the IP gateway 100 receives the voice packet signal from the LAN line, the data decoding unit 122 notifies the buffer capacity changing unit 129 to that effect, and sets the capacity of the reception buffer 116b for the voice signal. Change to buffer capacity.
[0043]
In general, if a part of the facsimile signal is lost, an accurate image cannot be generated. Therefore, it is preferable to avoid the loss of the facsimile signal as much as possible. On the other hand, even if a part of the audio signal is lost, the conversation between the transmitting side and the receiving side is hardly hindered. Therefore, here, the buffer capacity for the facsimile signal is set to a data capacity for 200 ms, the buffer capacity for the audio signal is set to a capacity for 100 ms, and the reception is performed when the voice signal is received and when the facsimile signal is received. The buffer capacity is changed. The facsimile signal buffer capacity and the audio signal buffer capacity can be set and changed from the external computer 105 via the serial bus controller 117. In addition, here, the buffer capacity changing unit 129 changes the buffer capacity of the reception buffer 116b to the set value by using the reception of the facsimile signal as a trigger, but the setting value of the buffer capacity from the external computer 105 is designated. As a trigger, the buffer capacity may be changed.
[0044]
As described above, in the present embodiment, even when a high-quality or large-capacity facsimile packet signal is transmitted and it takes a long time to receive it, a synchronization shift including a clock shift is detected at regular intervals. Since the deviation is corrected, the synchronization deviation amount does not exceed the capacity of the reception buffer due to the accumulation of the synchronization deviation, and the loss of image information can be minimized.
[0045]
In this embodiment, since the synchronization deviation including the clock deviation is eliminated in this way, it is not necessary to increase the reception buffer capacity unnecessarily, and the occurrence of the control procedure timeout due to the data delay corresponding to the reception buffer capacity is suppressed. be able to.
[0046]
In this embodiment, correction of synchronization deviation is performed by deleting data from the reception buffer or inserting data into the reception buffer. However, these corrections are performed during a period in which no signal is received. As a result, the facsimile control information and the facsimile image information in the facsimile signal are not affected at all, and the image formation and communication status are not adversely affected.
[0047]
Next, a second embodiment of the facsimile signal receiving apparatus will be described with reference to FIG.
[0048]
Some PBXs cannot execute packet processing as in the first embodiment described above, but some PBXs can execute packet processing. The present embodiment is an IP / PBX capable of executing this packet processing.
[0049]
The IP / PBX 200 according to the present embodiment includes a local line interface 201 connected to the general telephone 101 and the general facsimile apparatus 102, a local line interface 202 connected to the PSTN 110, a switch circuit 203, and a PBX that performs various controls. A control unit 204 and a plurality of IP trunks 206, 206, 206 that execute packet processing are provided.
[0050]
The PBX control unit 204 has a call control unit 205 that performs call control with the other party. Each IP trunk 206 basically has the same configuration as the packet signal transmission processing unit 130a of the first embodiment, and basically the same as the packet signal reception processing of the first embodiment. A packet signal reception processing unit 140a having the same configuration as that of the unit 140.
[0051]
As described above, the IP / PBX 200 of this embodiment includes the packet signal reception processing unit 140a having the same configuration as the packet signal reception processing unit 140 of the first embodiment. When a packet signal is sent, it is possible to correct synchronization deviation including clock deviation.
[0052]
Next, a third embodiment of the facsimile signal receiving apparatus will be described with reference to FIG.
[0053]
In general, some facsimile apparatuses cannot execute packet processing, but recently, those that execute packet processing have been considered. The present embodiment is an IP facsimile machine capable of executing this packet processing.
[0054]
The IP facsimile machine 300 according to the present embodiment includes a scanner mechanism 301 that captures image data, a printing mechanism 302 that forms an image, a facsimile control unit 303 that controls these mechanisms and performs call control, and the first embodiment. A packet signal transmission processing unit 130b having basically the same configuration as the packet signal transmission processing unit 130, and a packet signal reception processing unit 140b having basically the same configuration as the packet signal reception processing unit 140 of the first embodiment are also provided. ing. Note that the receiving unit 304a of the packet signal transmission processing unit 130b and the transmitting unit 304b of the packet signal reception processing unit 140b are both provided in the facsimile control unit interface 304.
[0055]
As described above, the present embodiment also includes the packet signal reception processing unit 140b having basically the same configuration as the packet signal reception processing unit 140 of the first embodiment. When the signal is sent, the synchronization shift including the clock shift can be corrected.
[0056]
By the way, since this IP facsimile apparatus 300 receives only a facsimile packet signal, the buffer capacity is not changed depending on whether the received signal is a voice signal or a facsimile signal. In this case, the buffer capacity may be changed. However, since a voice signal is also received with a telephone function, the buffer capacity is changed depending on whether the received signal is a voice signal or a facsimile signal, as in the first embodiment. It may be.
[0057]
【The invention's effect】
According to the present invention, even when a facsimile packet signal having a high image quality or a large capacity is sent and it takes a long time to receive it, a synchronization shift including a clock shift is detected at a fixed interval, and this synchronization shift is corrected. As a result, the amount of synchronization deviation does not exceed the capacity of the reception buffer due to the accumulation of synchronization deviation, and the loss of image information can be minimized. Therefore, in the present invention, as described above, the synchronization shift including the clock shift is eliminated, so that it is not necessary to increase the reception buffer capacity unnecessarily, and the control procedure time-out occurs due to the data delay corresponding to the reception buffer capacity. Can be suppressed.
[0058]
In the present invention, the synchronization shift is corrected by deleting the data from the reception buffer or inserting the data into the reception buffer. However, these corrections are performed during the period in which no signal is received. Therefore, the facsimile control information and the facsimile image information in the facsimile signal are not affected at all, and the image formation and communication status are not adversely affected.
[Brief description of the drawings]
FIG. 1 is a system diagram of a communication system in a first embodiment according to the present invention.
FIG. 2 is a circuit block diagram of a facsimile signal receiving apparatus (IP gateway) according to the first embodiment of the present invention.
FIG. 3 is a functional block diagram of a facsimile signal receiving apparatus (IP gateway) according to the first embodiment of the present invention.
FIG. 4 is an explanatory diagram showing synchronization shift detection and synchronization shift correction timing in the first embodiment according to the present invention.
FIG. 5 is a circuit block diagram of a facsimile signal receiving apparatus (IP / PBX) according to a second embodiment of the present invention.
FIG. 6 is a circuit block diagram of a facsimile signal receiving apparatus (IP facsimile apparatus) according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100,100a ... IP gateway, 101,101a ... General telephone, 102,102a ... General facsimile apparatus, 103,103a ... PBX, 109 ... IP network, 121a ... Packetization part, 121b ... Packet decomposition part, 122 ... Data decoding part , 123 ... synchronization deviation detection unit, 124 ... counter, 125 ... measurement period / synchronization deviation detection unit, 126 ... synchronization deviation amount accumulation unit, 128 ... in-buffer data increase / decrease unit, 129 ... buffer capacity change unit, 130, 130a, 130b ... packet signal transmission processing unit, 140, 140a, 140b ... packet signal reception processing unit, 200 ... IP / PBX, 300 ... IP facsimile machine.

Claims (8)

Receives an encoded and packetized facsimile signal from the facsimile signal transmitting apparatus via the IP network, decomposes the packetized facsimile signal, and temporarily receives data indicated by the decomposed facsimile signal. A facsimile signal receiving device that performs a decoding process on the data stored in the reception buffer,
In a method for correcting a synchronization shift of a facsimile signal receiving apparatus for correcting a synchronization shift with the facsimile signal transmitting apparatus,
A non-signal detection step of detecting a non-signal inserted between the facsimile control signal and the facsimile image information signal of a predetermined page and the facsimile control signal and the facsimile image information signal of the next page among the facsimile signals;
A synchronization shift detection step of detecting an amount of the synchronization shift from when the facsimile control signal is received until the non-signal is detected when the facsimile signal is received from the facsimile signal transmitting device;
During the no-signal period, the no-signal data in the reception buffer is deleted or the no-signal data is inserted into the reception buffer according to the amount of synchronization deviation detected in the synchronization deviation detection step. Buffer data increase / decrease process
A method for correcting synchronization deviation of a facsimile signal receiving apparatus, comprising: The method for correcting synchronization deviation of a facsimile signal receiving apparatus according to claim 1,
In the synchronization shift detection step, at least a synchronization shift amount during a period in which the facsimile image information signal is received among the facsimile signals is accumulated,
In the data increase / decrease step in the buffer, the non-signal data corresponding to the accumulated amount of the synchronization shift amount is deleted or inserted from the reception buffer.
A method of correcting a synchronization shift of a facsimile signal receiving apparatus. A facsimile that receives an encoded and packetized facsimile signal from the facsimile signal transmitting apparatus via the IP network, decomposes the packetized facsimile signal, and decodes the data indicated by the facsimile signal. In the signal receiving device,
A reception buffer for temporarily storing data indicated by the facsimile signal before the decoding process;
A non-signal detecting means for detecting a non-signal inserted between a facsimile control signal and a facsimile image information signal of a predetermined page and a facsimile control signal and a facsimile image information signal of the next page, among the facsimile signals;
When receiving the facsimile signal from the facsimile signal transmitting device, a synchronization shift detecting means for detecting the amount of synchronization shift between the reception of the facsimile control signal and the detection of the no signal;
During the period in which the no-signal detection means detects the no-signal, the no-signal data in the reception buffer is deleted or received according to the amount of synchronization deviation detected by the synchronization deviation detection means. In-buffer data increasing / decreasing means for inserting the no-signal data into the buffer;
A facsimile signal receiving apparatus comprising: The facsimile signal receiving apparatus according to claim 3,
The synchronization shift detection means includes synchronization shift amount storage means for storing a synchronization shift amount during a period in which at least the facsimile image information signal is received among the facsimile signals.
The data increase / decrease means in the buffer deletes or inserts the no-signal data corresponding to the amount of synchronization deviation accumulated in the amount of synchronization deviation accumulation means from the reception buffer.
A facsimile signal receiving apparatus. In the facsimile signal receiving apparatus according to any one of claims 3 and 4,
The data increase / decrease means in the buffer is in a no-signal period, and after the predetermined time has elapsed from the start of the no-signal period, deletes or inserts the no-signal data from the reception buffer.
A facsimile signal receiving apparatus. The facsimile signal receiving device according to any one of claims 3 to 5,
Buffer capacity changing means for changing the capacity of the reception buffer;
A facsimile signal receiving apparatus. The facsimile signal receiving apparatus according to claim 6,
The buffer capacity changing means changes the buffer capacity in accordance with an instruction from the outside.
A facsimile signal receiving apparatus. The facsimile signal receiving apparatus according to claim 6,
Decoding means for decoding whether a signal received via the IP network is the facsimile signal;
The buffer capacity changing means changes the buffer capacity when the decoding means decodes the received signal as the facsimile signal.
A facsimile signal receiving apparatus.

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