JPS58219868A - Transmitting device of facsimile - Google Patents

Abstract

PURPOSE:To optimize the quantity of generation of file codes and to guarantee the recording time of the receiving side by transmitting the file codes in accordance with the variation of picture signal generating time. CONSTITUTION:An encoding circuit 2 specifies the setting of a minimum guarrantee bits to a counting counter 3, generates a synchronizing signal, encodes a picture signal, and then writes the encoded signal in a memory 4. After completing the encoding of one line, the encoding circuit 2 discriminates whether the counted value by the counting circuit 3 reaches a set value or not, and when the set value is not reached, writes the file codes in the memory continuously until the set value is reached. Consequently, the number of codes in a line exceeds the minimum guarantee bits and the one-line recording time of the receiving side can be guaranteed. Subsequently, the encoding circuit 2 discriminates a picture signal controlling signal; starts the encoding of one line when the signal is on, supervises the number of codes in the memory 4 in case of off and generates file codes when the number of codes is less than a prescribed number.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a facsimile transmission apparatus in which the generation time of an image signal is variable and in which a fill code is added to code information obtained by encoding the image signal and transmitted.

In facsimile, the redundancy of image signals is suppressed by encoding to efficiently transmit them. In such encoding, the encoding efficiency changes depending on the redundancy of the image signal, and the amount of codes generated per unit time changes depending on the image signal.

For this reason, on the transmitting side, when transmitting codes at a constant speed, the transmission speed exceeds the generation speed of the image signal,
It may happen that the code cannot be transmitted normally. Also, on the receiving side, since the recording time of one line is constant, if the image signal is transmitted at a speed exceeding the recording time,
Recording becomes impossible.

Therefore, in a facsimile, a line synchronization signal (hereinafter referred to as "line synchronization signal") is transmitted for each line as shown in FIG.

(referred to as EOL). If the number of codes for one line of image signal is small, a necessary number of fill codes are added between the image signal and EOL. As a result, the minimum number of codes required for one line signal (hereinafter referred to as minimum guaranteed bits)
ensure that For example, when the image signal generation time on the transmitting side and the recording time on the receiving side are both l Q mll / line and the transmission speed is 9600 bp8, the minimum guaranteed bit is 9
6 bits are required, and the sum of EOL and code is 966-p.
) In the following cases, a fill code will be added for the missing amount.

Furthermore, the general facsimile Z9 not only transmits image signals, but also creates the necessary text reports by itself.
Image information and text ttwt are combined and transmitted. In this case, both the image information and the character information are encoded as an image signal for each line in the main scanning direction, but the generation time of the image signal may differ between the image information and the character information. When determining the minimum guaranteed number of bits, it is necessary to adjust it to the slowest generation time, so when the image signal has a fast generation time, it is necessary to transmit many fill codes, which reduces the communication cost. There were problems such as high prices.

The present invention eliminates such problems and the transmission side 7 axis I
Even if the generation time of the JO image signal changes significantly, the code is always sent at a constant speed, the receiving facsimile can record the code normally, and the optimum amount of code is required to minimize the reduction in transmission efficiency. The objective is to provide a facsimile machine to which a fill code can be added.

The present invention is characterized by a counting circuit that counts codes and stops counting when a reference value that can be set arbitrarily is reached and indicates that the reference value has been reached, and that performs EOL generation generation 1 transmission coding and fill code generation. A code circuit and a code outputted by the coding circuit are written and read out in synchronization with the transmission timing.
It consists of a memory circuit (abbreviated as FIFO) with 7 first-in, first-out functions that can indicate this to the outside when the internal code amount falls below a certain value, and the encoding circuit encodes one line. After finishing, Katsuko FI
- This is a facsimile machine that uses this counting circuit only when the code amount within a circle is less than a specified value (zft) and sends out a fill code so that the receiving facsimile machine does not become unable to record.

The present invention will be explained in detail below with reference to Examples.

FIG. 2 shows a block diagram of an embodiment of the present invention, in which 1 is an image signal generation circuit, 2 is an encoding circuit, 3 is a counting circuit, and 4 is a FIFO. 1 image signal generation circuit is 2
An image signal is generated for the encoding circuit in units of one line.

FIG. 3 is a time chart showing how the image signal generation circuit 1 generates the image signal. The image signal generation circuit 1 provides the encoding circuit 2 with the image signal control signal ON.
Indicates that there is an encoding request and an image signal, and the image signal control signal O
The FF indicates the initial state or the request for completion of encoding.

During the period when the image signal control signal is ON, encoding processing for 1 line is performed, and during the period when the image signal control signal is OFF, the period is the generation time of one image signal, and the time changes indefinitely.

The encoding circuit No. 2 has the functions of generating E(JL, encoding the image signal, and generating fill codes, and the generation speed of each code is sufficiently faster than the transmission speed.

The counting circuit 3 can set the number of bits and bits guaranteed to be low and low, which is determined by the product of the recording time on the receiving side and the transmission speed, according to the instructions from the encoding circuit 2, and the code north circuit □ route of 2 can be set. When writing 1 code into FIFO No. 4, the number of codes to be written at the same time is counted, and when the counted value reaches the minimum guaranteed number of bits set earlier, it indicates that it has reached the encoding circuit No. 2, and subsequent counting is performed. It has the function to cancel.

4)'IFO includes the code tS output by the encoding circuit 2, reads out the code in synchronization with the transmission timing,
This memory circuit has a first-in first-out function that can indicate this to the encoding circuit 2 when the internal code value falls below a specified value.

The specified value is the minimum code of 1.2 necessary to prevent the state in which the code in the FIFO of No. 4 runs out while the encoding circuit No. 2 is performing encoding processing (referred to as an underflow state).
The amount of code encoded for one line in the encoding circuit is determined by the product of the minimum image signal encoding processing time and the transmission speed.

The memory capacity of FIFO 4 shall be greater than the specified value.

Next, the operation of this embodiment will be explained.

When the image signal control signal is turned ON from the first image signal generation circuit to the second encoding circuit, encoding of one line is started. After the encoding circuit 2 instructs the counting circuit 3 to set the minimum guaranteed bit, it encodes the EUL generated one-picture signal and writes it into the FIFO 4. Further, the counting circuit 3 counts the codes written. When the encoding circuit 2 finishes encoding one line, the counting circuit 3 judges whether it has reached the set value, and if it has, the fill code will not be generated. writes to the FIFO with fill code t-4 until it is reached. Through the above processing, the number of codes for one line is not less than the minimum guaranteed number of bits, and the recording time for one line on the receiving side can be guaranteed.

Next, the encoding circuit 2 determines the image signal control signal and turns ON.
In this case, encoding of one line is started.

In addition, in the case of OFF, while waiting for the image signal control signal 0NK-
The amount of codes in the FIFO of No. 4 is monitored, and if the amount of codes is above a specified value, nothing is done, and when it is below the specified value, a fill code is generated.

This process continues until the image signal control signal is turned ON.

Therefore, even if the image signal generation time fluctuates, the fill code generation amount is optimized because the amount of fill codes corresponding to the fluctuation is transmitted.

As explained above, the present invention performs fill code generation using two types of processing, guarantees the recording time on the receiving side, and maintains the transmission speed according to the code no matter how the generation cycle of the image signal changes. It is possible to send out an optimal amount of fill codes without exceeding the amount generated.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the format of codes transmitted by facsimile, Fig. 2 is a professional configuration diagram showing an embodiment of the present invention, and Fig. 3 is a time diagram showing how image signals are generated. It's a chart. In the figure, 1... image signal generation circuit, 2... code IHI envelope, 3... counting circuit, 4... memory circuit. be.

Claims (2)

[Claims] (1) Transmission and reception of the image signal in a facsimile transmission device in which the image signal is collectively encoded for each scan, a synchronization signal is inserted for each scan, and the code length of the image signal for each scan is different. A facsimile transmission device characterized in that the image signal is transmitted and received via a buffer register with a constant capacity.・ (2) In a facsimile transmission device in which the time at which the image signal is generated changes and the skeleton image signal is encoded, the element that generates the end-of-line code, the element that encodes the 0-image signal, and the element that generates the call signal code and the fill code. An encoding circuit consisting of a generating element and a code generated by the encoding circuit are counted, and when the counted value reaches a reference value that can be set arbitrarily, subsequent counting is stopped and it is determined that the reference value has been reached. Writes the code generated by the counting circuit and the encoding circuit, reads the written code in synchronization with the transmission timing, and indicates externally when the internal code amount falls below a specified value. and a memory circuit with a first-in-first-out function that can perform a first-in, first-out function, and in the encoding circuit, when the encoding of one line is completed, if the counting circuit does not reach the reference value, generates a fill code until the reference value is reached. Claim (1), characterized in that the fill code is generated only when the next image signal is not generated after the image signal is generated and the amount of code in the memory circuit becomes less than a specified value. The facsimile transmission device described in Section 1.