JP2783182B2 - Facsimile communication terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile communication terminal device which includes a modem and performs facsimile communication with a connection destination device of a communication line established through an exchange.

[0002]

2. Description of the Related Art Conventionally, in a facsimile communication terminal device of this type, when an original is transmitted, the original image is transmitted while being scanned and read line by line while performing an encoding process for data compression. On the other hand, the facsimile communication terminal device on the receiving side sets the maximum value of the communication time for each encoded scan line in advance to limit the line occupation time during image communication, and sets the reception time for one scan line of the received image. Is exceeded, the line is disconnected. The maximum value of the communication time for each encoded scan line is ITU
-T Recommendation T. 4, the facsimile communication terminal device according to the recommendation sets the maximum communication time for each coded scanning line to 13 seconds, and sets the maximum reception time for one scanning line of the received image to the maximum value. If the value is exceeded, the line is disconnected.

[0003]

However, the transmission time of one line of an image varies depending on the scanning length of the image. For example, when a document image is read at a resolution of 16 lines / mm and transmitted, the scanning length of the document is I
In the case of SO-A4, ISO-B4 and ISO-A3,
The read image information is subjected to a two-dimensional encoding process to perform transmission speed 2
When transmitting at 400 bps, the maximum value of the transmission time for one line is as shown in FIG.

In FIG. 2, the maximum code data amount in the two-dimensional encoding process (MR) is obtained as follows. In the two-dimensional encoding process (MR), the position of each changing pixel on the encoding line corresponds to the position of the pixel on the encoding line and the position of the reference pixel on the reference line, and is determined in the pass mode / vertical mode / horizontal mode. One of them is selected and the encoding process is performed. When the reference line is composed of all white pixels and the encoding line is composed of pixels of alternating black and white (see FIG. 3),
The code data amount is the largest. The code word of this image pattern is defined in ITU-T Recommendation T. 4 is selected. The data amount per scanning line is determined by the code data and the line synchronization code (EO
L + additional bit).

Therefore, the code data amount per scanning line is as follows: N2 = H (0,1) + H (1,1) (S-4) / 2 + VL (2) + VL (1) + V (0) + (EOL + additional bit ) = (3 + 8 + 3) + (3 + 6 + 3). (S-4) / 2 + 6 + 3 + 1 + (12 + 1) = 6S + 13 where N2: maximum code data amount per scanning line S: number of scanning line pixels H and V are horizontal mode and vertical mode, respectively. Indicates the mode code. H (0,1): 001 001110101 010 H (1,1): 001 0001111 010 VL (2): 000010 VL (1): 010 V (0): 1

As described above, the maximum transmission time of one line of an image varies depending on the size of a transmission image. However, a conventional facsimile communication terminal apparatus receives an ITU-T Recommendation T.30 when receiving image data. According to No. 4, since the maximum value of the communication time for each encoded scan line is set to 13 seconds, the apparatus is in a state of waiting for transmission data for 13 seconds, and is electrically connected to the line. Therefore, for example, when receiving an image of the ISO-A4 size, the reception time of one scanning line is completed in 8.8 seconds or less, and the line is additionally connected for the remaining 4.2 seconds. For this reason, for example, even if there is some abnormality on the transmission side and transmission is stopped, the line is additionally connected to the line for 4.2 seconds on the reception side, and during this time, another facsimile communication terminal device For example, there is a problem that the transmission becomes busy and the facsimile cannot be received.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. It is an object of the present invention to optimally set the maximum value of the reception time of one scanning line for each communication at the time of facsimile reception. Accordingly, it is an object of the present invention to provide a facsimile communication terminal device capable of realizing reliable and high-speed communication.

[0008]

In order to achieve the above object, a first invention (an invention according to claim 1) comprises scanning length information, scanning line density information, and encoding method in received image data.
The maximum value of the reception time of one scanning line is determined based on the information and the communication speed information, and the line is disconnected when the reception time of one scanning line of the received image data exceeds the maximum value. is there. The second invention (the invention according to claim 2) determines the maximum value of the reception time of one scanning line based on the scanning length information, the scanning line density information, the encoding method information and the communication speed information in the received image data. And monitor
When the reception time of one scan line of received image data exceeds the maximum value, the line is disconnected .

[0009]

According to the present invention, therefore, in the first invention,
Scan length information, scan line density information, code in received image data
The maximum value of the reception time of one scanning line is determined based on the conversion scheme information and the communication speed information. If the reception time of one scanning line of the received image data exceeds the maximum value, the line is disconnected. In the second invention, the maximum value of the reception time for one scanning line is determined and monitored based on the scanning length information, scanning line density information, coding method information and communication speed information in the received image data.
If the receiving time of one scan line of the received image data exceeds the maximum value, the line is disconnected.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. FIG. 1 is a functional block diagram showing a main part of a facsimile communication terminal apparatus showing one embodiment of the present invention. In the figure, 1 is a modem, 2 is a communication procedure circuit, 3 is a decoding circuit, 4 is a maximum transmission time determination circuit, and 5 is a maximum transmission time monitoring circuit.

In this facsimile communication terminal,
The received image signal (received image data) is transmitted to the modem 1
Through the communication procedure circuit 2. Communication procedure circuit 2
In the pre-message procedure, knows document size information (scan length information), scanning line density information, encoding method information, and data communication speed information in the received image data, and notifies these information to the maximum transmission time determination circuit 4. I do.

The maximum transmission time determination circuit 4 determines the maximum value Tmax of the reception time for one scanning line based on the document size information, scanning line density information, coding method information and data communication speed information from the communication procedure circuit 2. I do. That is, in FIG. 2, when the document size is ISO-A4, 8.8 seconds, when the document size is ISO-B4, 10.4 seconds, and when ISO-A3
Is 12.4 seconds, the maximum value T of the reception time for one scanning line.
max is determined.

The maximum value Tmax of the reception time of one scanning line determined by the maximum transmission time determination circuit 4 is given to a maximum value transmission time monitoring circuit 5. Maximum value transmission time monitoring circuit 5
Receives the coded scan line start signal S1 from the decoding circuit 3 and monitors the time since the coded scan line start signal S1 was input.
If the coded scan line end signal S2 is not input from the decoding circuit 3 even if the maximum value Tmax exceeds the maximum value Tmax, that is, if the reception time of one scan line of the received image data exceeds the maximum value Tmax, the communication procedure circuit 2 To a line disconnection instruction signal S3 for instructing disconnection of the line.

As can be understood from the above description, according to this embodiment, the maximum value of the reception time of one scanning line is optimally set for each communication at the time of facsimile reception, thereby realizing reliable and high-speed communication. Can be. That is, according to the present embodiment, when a failure occurs on the transmission side or an abnormality occurs on the communication line, the reception side is not connected to the line for more than the required time, so image information from another facsimile communication terminal device is immediately transmitted. It becomes possible to receive.

[0015]

As is apparent from the above description, according to the present invention, according to the first invention, scanning in received image data is performed.
Length information, scanning line density information, coding method information and communication speed
The maximum value of the reception time of one scan line is determined based on the degree information, and if the reception time of one scan line of the received image data exceeds the maximum value, the line is disconnected. scanning length information, the scanning line density information, the maximum value of the reception time of one scanning line on the basis of the coding method information and the communication speed information is determined, the reception time of one scan line of the received image data being monitored up to its If the value exceeds the value, the line is disconnected, during off Akushimiri reception, optimally it becomes possible to set for each communication maximum value of the reception time of one scan line, it is possible to realize a reliable and high-speed communication Become like For example, when a failure occurs on the transmission side or an abnormality occurs on the communication line, the reception side is not connected to the line for a longer time than necessary, so that it is possible to immediately receive image information from another facsimile communication terminal device. .

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating a main part of a facsimile communication terminal apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a transmission time with respect to the number of scanning line pixels.

FIG. 3 is a diagram for describing a maximum code data amount in a two-dimensional encoding process (MR).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Modulator / demodulator, 2 ... Communication procedure circuit, 3 ... Decoding circuit, 4
... Maximum transmission time determination circuit, 5 ... Maximum transmission time monitoring circuit.

Claims (2)

(57) [Claims] 1. Scanning length information and scanning lines in received image data
Maximum value determining means for determining a maximum value of the reception time of one scan line based on density information, coding method information and communication speed information; and reception time of one scan line of the received image data is determined by the maximum value determination means. And a line disconnecting means for disconnecting the line when the maximum value is exceeded. 2. Maximum value determining means for determining a maximum value of a reception time of one scanning line based on scanning length information, scanning line density information, encoding method information and communication speed information in received image data, and Monitor the reception time of one scan line of data,
A facsimile communication terminal device comprising: a line disconnecting unit that disconnects a line when the reception time of the received signal exceeds the maximum value determined by the maximum value determining unit.