JPH0420552B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a facsimile transmission device.

BACKGROUND ART FIG. 3 is a block diagram showing an example of a conventional facsimile transmitter that employs a one-dimensional encoding or two-dimensional encoding method. The device shown in this figure includes a reading section 1 consisting of an image sensor such as a CCD, a line memory control section 2 that temporarily stores calligraphic information signals obtained by the reading section 1, and a line memory control section 2 that temporarily stores calligraphic information signals obtained by the reading section 1. a one-dimensional or two-dimensional encoder 3 that extracts and encodes the written image information signal; an S/P (serial/parallel) conversion circuit 5 that converts the output of the encoder 3 into a parallel signal; a code data buffer memory 6 for temporarily storing the signal obtained by the /P conversion circuit 5;
The facsimile apparatus is comprised of a modulation/demodulation section 7 that converts the output of the code data buffer memory 6 into a transmission signal, and a control section 4 that controls the entire facsimile, and operates as described below.

First, under the control of the control section 4, the calligraphic information signal output from the reading section 1 is transferred to the line memory control section 2.
is stored in The encoder 3 reads out the drawing information signal from the line memory control section 2, creates one-dimensional or two-dimensional encoded data based on this, and sends it to the S/P conversion circuit 5. The S/P conversion circuit 5 performs S/P conversion on the serial code data, and the parallel code data obtained here is once stored in the code data buffer memory 6, and then
The signal is transmitted to the line through the modulation/demodulation section 7.

Problems to be Solved by the Invention By the way, the encoder 3 described above uses encoded code data and a line synchronization code as shown in FIG.
If the length added with the EOL does not satisfy the minimum transmission time T per scanning line determined by the pre-message procedure, a fill bit is added after the code data.
Insert FILL and these line sync codes EOL,
Code data and fill bit FILL to one of the scanning lines
Send as line data. This makes it possible to secure sufficient decoding processing time and sufficient recording time on the receiving side.

For this reason, in conventional facsimile transmission devices, file bits must be managed for each line, and it takes much longer than the time n·T to transmit line data for n scanning lines. , it couldn't be any shorter.

The problem is that if the transmitting side sends a signal at a high speed, the receiving side will not be able to record it and the buffer provided on the receiving side will overflow. This happens because T is determined. Therefore,
It is possible to pay attention to the white line and send a special skip signal instead of sending this white line, thereby reducing fill bit FILL, but in this case, the printing speed on the receiving side should be increased. Otherwise, there is a problem of overflow of code data.

The present invention solves the above conventional problems,
CCITT's T.4 (facsimile communication standard) without using a special line-skipping method and without overflow of coded data on the receiving side.
It is an object of the present invention to provide a facsimile transmitting apparatus that can reduce redundancy of coded data by reducing fill bits while using an encoding method based on the above.

Means for Solving the Problems In order to achieve this object, the present invention provides a facsimile transmission device that compresses and transmits a calligraphic information signal using a one-dimensional encoding or two-dimensional encoding compression method. An encoder that performs one-dimensional encoding or two-dimensional encoding, a generated code counter that counts the number of bits of encoded data obtained by the encoder, and a code that counts the number of scanning lines of the encoded data string obtained by the encoder. and a control section that adds fill bits to a block of encoded data obtained by the encoder based on the counted value of the encoded scanning line counter and the counted value of the generated code counter. .

Effect The present invention is characterized by the number of bits of generated code data,
By counting the number of encoded lines,
The minimum transmission time is calculated for a block of generated code data, and if the generated code data does not satisfy the minimum transmission time, fill bits are generated and added in block units, and thereby each line of code data is This makes it possible to transmit data using fewer bits than when adding fill bits to the data.

Embodiment FIG. 1 is a block diagram showing an embodiment of a facsimile transmission apparatus according to the present invention. The device shown in this figure includes a reading section 11 and a line memory control section 1.
2, an encoder 13, a control unit 14, an S/P conversion circuit 15, a code data buffer memory 16,
It is configured to include a conversion demodulation section 17.

The reading unit 11 has an image sensor such as a CCD, and reads the original (calligraphy and drawings) line by line under the control of the control unit 14, and the calligraphy information signal obtained by reading the original is sent to the line memory control unit. 12.

The line memory control unit 12 temporarily stores the calligraphy information signal for a predetermined number of lines, for example, several lines, and supplies the readout detection information at this time to the control unit 14, and the information is stored here. The drawing information signal is supplied to the encoder 13 in response to an access signal from the encoder 13.

The encoder 13 accesses the line memory control section 12 in response to a control signal from the controller 14, reads out the necessary bibliography signal, and encodes it one-dimensionally or two-dimensionally. Generates one clock every time one bit of code data including the line synchronization code EOL is generated, and generates a one-line encoding end signal when one line (one scanning line) is encoded. The encoded data is supplied to the S/P conversion circuit 15, and the clock and 1-line encoding end signal are supplied to the control section 14. Note that this encoder 13 does not generate fill bits even if the length of code data including the line synchronization code EOL is less than the minimum transmission time T.

The control unit 14 includes an encoded scanning line counter 18 that counts the one-line encoding end signal, and a generated code counter 19 that counts the clock,
It generates fill bits based on the count values of the encoded scanning line counter 18 and generated code counter 19 while controlling each part of the circuit, and operates as described below.

First, the control unit 14 sends a start signal for encoding one line to the encoder 13, thereby starting encoding one line. Next, this control section 14 outputs one clock every time the encoder 13 outputs one clock.
The generated code counter 19 is counted up to count the number of bits of generated code data, and each time the encoder 13 outputs a 1-line encoding end signal, the encoded scanning line counter 18 is counted up to perform encoding. The number of lines is counted, and the count value of the generated code counter 19 (line synchronization signal
When the total number of code data bits (including EOL) B is equal to or exceeds the predefined number M of block data bits, data generation for one block is completed and fill bits are generated for this block. The number of fill bits F for this block is given by the following equation.

F=n・T・A−B However, n: Count value of encoded scanning line counter 18 T: Minimum transmission time of code data including line synchronization signal EOL A: Transmission speed of modulation/demodulation section 17 B: Line synchronization signal EOL In this formula, if the number of fill bits F is negative or O, this block satisfies the block minimum transmission time based on the minimum transmission time T, so no fill bits are generated. Generated code counter 19
Then, the encoded scanning line counter 18 is reset and the next block is encoded.

Also, in the above formula, if the fill bit number F is positive,
Since this block does not satisfy the minimum block transmission time, the control unit 14 generates F fill bits and sends them to the S/P conversion circuit 15, and then the generated code counter 19, encoded scanning line counter 18.

The S/P conversion circuit 15 receives code data (including line synchronization signal EOL) output from the encoder 13.
The data obtained in this process is temporarily stored in the code data buffer memory 16, and then
A modulation/demodulation section 17 controlled by the control section 14
It is converted into a transmission signal and sent out to the line.

As described above, in this embodiment, fill bits are added to blocks without adding fill bits to each line of code data, so that the modulation/demodulation section 17 outputs a signal shown in the format shown in FIG. be done.

Effects of the Invention As explained above, in the present invention, file management is performed not for each scanning line but for each block.
If one block contains a scanning line in which the generated code data sufficiently satisfies the minimum transmission time and a scanning line in which the generated code data does not satisfy the minimum transmission time, the generated code sufficiently satisfies the minimum transmission time. It serves as a fill for scan lines whose data does not meet the minimum transmission time, and can reduce the fill for the entire block, ie, the redundancy of the compression code.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a facsimile transmitter according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of the format of a transmitted signal in the same embodiment, FIG. 3 is a block diagram of a conventional facsimile transmitter, and FIG.
This figure shows the format of a transmission signal output from the facsimile transmitter shown in FIG. 3. 13... Encoder, 14... Control unit, 15...
S/P conversion circuit, 18... Encoded scanning line counter, 19... Generated code counter.

Claims (1)

[Claims] 1. An encoding means for encoding a calligraphy information signal, a generated code counting means for counting the number of bits of encoded data obtained by the encoding means, and a number of scanning lines of the encoded data string obtained by the encoding means. When the count value of the generated code counting means reaches a predetermined value, the bit value calculated based on the counted value of the encoded scanning counting means and the generated code counting means. 1. A facsimile transmitting apparatus comprising: a control means for comparing the counted value with a count value and adding fill bits to the encoded data obtained by the encoding means based on the comparison result.