JPH03285453A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To improve the throughput of a CPU by using a recording and reproducing buffer, which is composed of plural steps with first-in first-out configuration, instead of buffers for recording and reproducing. CONSTITUTION:An output 3c of a CPU 3 is bidirectionally connected with recording and reproducing buffers 6 (6a, 6b and 6c) composed of three steps with the first-in first-out configuration. Since the recording and reproducing buffer 6 is composed of three steps, when a write signal is made active to the CPU 3, respective data A, B and C are continuously written to the recording and reproducing buffer 6 by the write signals for the respective data A, B and C of 8 bits. Thus, the respective data A, B and C written to the recording and reproducing buffer 6 are converted from the parallel data of sequential 8 bits to serial data by a parallel/serial conversion part 7 in the next step and recorded to a magnetic tape after being modulated by a modulation circuit 8 later.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention modulates digital data such as image data sent from a terminal on the other end and records it on a magnetic recording medium. The present invention relates to a facsimile device capable of reproducing .

(Prior Art) An example of the electrical configuration of a conventional facsimile machine that is capable of MFM modulating digital data sent from a terminal on the other end, recording it on a magnetic recording medium, and reproducing the recorded data will be described below. As shown in the figure.

In the figure, image data taken in via a modem (not shown) is temporarily written into a recording buffer 32 under the control of the CPU 3i. The written data is then converted from 8-bit parallel data to serial data in the next stage parallel/serial converter 33. Here, the conversion speed from parallel data to serial data is 12 kbρS. Thereafter, the converted serial data is modulated into MFM data by an MFM modulation circuit 34, amplified by an amplifier (not shown) to a level necessary for recording, and then recorded on a magnetic tape.

On the other hand, when reproducing image data from a magnetic tape recorded in this way, first the MF recorded on the magnetic tape is
After the M data is reproduced and amplified to a level necessary for subsequent signal processing in an amplifier (not shown), the MFM data is converted into digital serial data in the MFM demodulation circuit 35. The converted serial data is then converted into 8-bit parallel data in the serial/parallel converter 36, and then sent to the next stage reproduction buffer 37.
will be written to. This allows the CPU 31 to read the 8-bit parallel data written in the reproduction buffer 37.

(Problems to be Solved by the Invention) The circuit system having the above configuration has a simple circuit configuration because the recording buffer and the reproduction buffer are provided separately. However, if the speed of recording on a magnetic tape or the speed of reproducing from a magnetic tape is, for example, 12 kbps,
Then, during tape recording, the CPU 31 inputs approximately 0.6 m5ec (# 1 / 1
This means that the recording data must be written within 2 kbps x 8 pints. Similarly, during tape playback, playback data must be read from the playback buffer 37 within about 0.6m5ec.

This point will be explained in detail with reference to the timing chart of FIG.

That is, when the interrupt signal to the CPU 31 becomes active (Low), the CPU 31 writes 8-bit parallel data A to the recording buffer 32 in response to a write signal. At this time, the parallel/serial converter 33 is converting the previous data, and one
/ 12kbpsx 3 bits #It will take 0.67m5ec. Then, after 0.6m5ec, the CPU
31 is interrupted, and the next 8-bit parallel data B is written into the recording buffer 32. In this way, the CPU 31 has to write data every 0.6 tssec.

By the way, in a facsimile machine, the CPU 31 has quite a large number of tasks, so it is difficult to read and write data within 0.6m5ec, and even if it is possible to read and write data, this will reduce the processing ability of the CPU 31. This caused problems such as affecting other tasks.

To solve this problem, an external memory is used instead of the recording buffer 32 and the playback buffer 37, and the DMA
(Direct Memory Access) may be used for high-speed transfer, but this creates new problems such as complicating the control circuit and increasing cost.

The present invention was made in view of the above circumstances, and its purpose is to avoid reducing the processing power of the CPU, and to
It is an object of the present invention to provide a facsimile machine in which the sofa is made into a cylinder and the circuit configuration is simplified.

(Means for Solving the Problems) In order to solve the above problems, the facsimile device of the present invention modulates digital data such as image data sent from a terminal on the other end using MFM and records it on a magnetic recording medium. A facsimile device capable of reproducing the recorded data includes a recording buffer that temporarily stores the digital data sent from the other party's terminal before recording it on the magnetic recording medium, and a recording buffer that temporarily stores the digital data sent from the other party's terminal, and the data recorded on the magnetic recording medium. The playback buffer that temporarily stores the playback data during playback is shared by a recording/playback buffer consisting of multiple stages with a first-in, first-out configuration.

(Operation) A recording buffer and a reproduction buffer are shared by a recording/reproducing buffer consisting of multiple stages with a first-in/first-out configuration.

For example, by using a three-stage buffer configuration, approximately 2m
5ec (#1/12kbpsX 8 pintos 3
), and the processing capacity of the CPU can be improved. In addition, since recording to the magnetic tape and reproducing from the magnetic tape are not performed at the same time, but are shared by a recording/reproducing buffer, the buffer can be simplified, and only one buffer control circuit is required. The circuit can also be simplified.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the electrical configuration of a facsimile apparatus according to the present invention.

In the figure, a communication line 1 that connects with a terminal on the other end (not shown) is led to a modem 2 that converts image data, which is an analog signal, into digital data in 8-bit units, and the output of the modem 2 is transmitted to a CPU 3. guided by. The output 3a of the CPU 3 is bidirectionally connected to a memory 5 that temporarily stores digital data in units of 8 bits, which is the input image data, and the other output 3b is connected to a memory 5 equipped with a printer or the like. It is led to part 4. Also, C
The output 3C of the PU 3 is a recording/reproducing buffer 6 (6a, .

6b, 6c) are bidirectionally connected. The output of the recording/reproducing buffer 6a is led to a parallel/serial converter 7 that converts 8-bit parallel data into serial data, and the output of the parallel/serial converter 7 is
It is led to an MFM modulation circuit 8 that modulates the serial data into MFM data. The output of the MFM modulation circuit 8 modulated into MFM data is led to a tape recording/reproducing amplifier 9 which amplifies it to the level required for recording on the magnetic tape.The output of the tape recording/reproducing amplifier 9 is not shown. The tape is guided to a cassette tape section 10 equipped with a recording head for recording on magnetic tape.

On the other hand, the output of the cassette tape section 10 equipped with a playback head for playing back data recorded on the magnetic tape is led to a tape recording/reproducing amplifier 9 that amplifies it to the level required for subsequent signal processing. The output of re-amplifier 9 is
M that converts MFM data into digital serial data
The signal is guided to an FM demodulation circuit 11. The output of the MFM demodulation circuit 11 is led to a serial/parallel converter 12 that converts serial data into 8-bit parallel data, and the output of the serial/parallel converter 12 is
It has a configuration in which it is led to a recording/reproducing buffer 6C.

The recording/playback buffer 6 is a first-in, first-out buffer consisting of three stages of 8 bits, so it is approximately 2
m5ec (#1/12 kbps x 8 bits x 3 stages) time can be obtained, and the processing capacity of the CPU 3 can be improved.

Next, the operation of the facsimile machine having the above configuration will be explained with reference to the timing chart shown in FIG.

During recording, image data sent from the communication line '4IA1 is received by the modem 2 and converted into digital data in 8-bit units (see FIG. 2). This converted digital data is temporarily stored in the memory 5 by the CPU 3 at the next stage. The data is transferred from the memory 5 to the recording/reproducing buffer 6 when either the memory 5 becomes full or the image data from the communication line 1 disappears.

Since the recording/reproducing buffer 6 has a three-stage configuration, the CPU
When the write signal becomes active (Low) for 8-bit data A, B, and C, each data A is stored in the recording/reproducing buffer 6.

B and C will be written successively. That is, C
PU3 is 1/12kbpsx 8 bits x 3 steps 2
It is sufficient to write data at a time interval of m5ec. Here, data B shows signal waveforms of each part when C2 (HEx) is written, and data C shows signal waveforms of each part when D3 (HEx) is written.

Each of the data A, B, and C written in the recording/reproducing buffer 6 in this way is sequentially converted from 8-bit parallel data to serial data in the next parallel/serial converter 7, and then the MFM modulation circuit 8 The data is modulated into MFM data in the tape recording/reproducing amplifier 9, amplified to a level necessary for recording, and then recorded on a magnetic tape loaded in the cassette tape unit 10.

On the other hand, when reproducing image data from a magnetic tape recorded in this way, first the MF recorded on the magnetic tape is
After the M data is reproduced and amplified to a level necessary for subsequent signal processing in the tape recording/reproducing amplifier 9, the MFM data is converted into digital serial data in the MFM demodulation circuit 11. Then, the converted serial data is converted into 8-bit parallel data in the serial/parallel converter 12, and sequentially written to the next stage recording/playback buffer processor. As a result, the CPU 3 receives the 8-bit parallel data A and B written in the recording/reproducing buffer 6.
, C are sequentially read and stored in the memory 5.

When transferring the image data stored in the memory 5 to another facsimile device, the CPU 3 reads the image data from the memory 5 and sends it to the communication line 1 via the modem 2. Also, if you want to print, the recording section 4
It is designed to be printed out.

(Effects of the Invention) The facsimile apparatus of the present invention has a structure in which a recording buffer and a reproduction buffer are shared by a recording/reproducing buffer consisting of multiple stages with a first-in/first-out configuration. Since it is possible to obtain a longer time by 10 minutes, the processing capacity of the CPU can be improved. In addition, since recording to the magnetic tape and reproducing from the magnetic tape are not performed at the same time, but are shared by a recording/reproducing buffer, the buffer can be simplified, and only one buffer control circuit is required. This also has the effect of simplifying the circuit.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the electrical configuration of the facsimile machine of the present invention, Fig. 2 is a diagram showing an example of dividing image data into 8-bit units and converting it into parallel data, and Fig. 3 shows the operation of the same device. Timing chart for explaining, Part 4
The figure is a block diagram showing the electrical configuration of a conventional facsimile machine, and FIG. 5 is a timing chart for explaining the operation of the same machine. 1...Communication line 2...Modem 3...CPU 4...Recording section 5...Memory 6...Recording/reproduction buffer 7...Parallel/serial conversion section 8...MFM modulation circuit 9...Tape recording/reproducing amplifier 10...Cassette tape section 11...MFM demodulation circuit 12...Serial/parallel converter first circuit Q95? -111+P7-1 Figure 2 Figure 4 Figure 1 / Voluntary procedure amendment March 28, 1991

Claims (1)

[Claims] 1) In a facsimile device capable of MFM modulating digital data such as image data sent from a terminal on the other party's side and recording it on a magnetic recording medium, as well as reproducing the recorded data, A recording buffer that temporarily stores the digital data sent from a terminal before being recorded on the magnetic recording medium, and a reproduction buffer that temporarily stores the reproduced data when reproducing the data recorded on the magnetic recording medium. A facsimile apparatus is characterized in that it is shared by a recording/reproducing buffer consisting of a plurality of stages having a first-in, first-out configuration.