JPH0666848B2 - Facsimile broadcasting receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention provides a facsimile signal composed of binary information by newly providing a second subcarrier in the audio frequency band of a current television signal. The present invention relates to a facsimile broadcast receiving apparatus that receives a transmitted facsimile broadcast signal by performing phase differential phase modulation, and more specifically, relates to a processing unit for processing a facsimile image signal in the facsimile broadcast signal.

<Outline of the Invention> The present invention relates to a facsimile broadcast receiving apparatus capable of obtaining good print quality with a buffer memory having a small capacity as much as possible even if the time when one line of facsimile image information is transmitted changes.

<Prior Art> In recent years, various organizations have been studying for the purpose of putting digital facsimile broadcasting in which a facsimile signal is transmitted by the second subcarrier as described above into practical use. FIG. 2 shows a part of the facsimile signal frame structure in the provisional specifications.

According to FIG. 2, one packet of data consists of a mode control code (MC) 16 bits and a prefix (PFX) 1
It is composed of 4 bits, 176 bits of information part, and 82 bits of check code, for a total of 288 bits. Furthermore, one frame of data is composed of 32 packets of packet data and 16 bits of frame synchronization signal (FC), a total of 9232 bits, and the data transmission rate is 16 kbps. The image information of the facsimile signal is stored and transmitted in the 176-bit information portion of the frame information of the facsimile signal shown in FIG. Therefore, the capacity of the image information of the facsimile signal that can be transmitted in one frame is 5632 bits, and the actual transmission speed of the image information of the facsimile signal is approximately
It will be 9.76 kbps. The printing speed for one line is 5 ms. The transmission speed of image information is guaranteed so that it does not exceed the printing speed (5 ms) of one line, no matter how good the compression efficiency of the image information is (pixels of one line are all white or all black). As described above, in the transmission specifications of image information of facsimile broadcasting, when the compression efficiency of the image information is good (when the transmission speed is high), the guarantee of the transmission speed is stipulated. If there is a bad condition, there is no guarantee. Therefore, depending on the image, the transmission time of the image information for one line may become long or short, or may change extremely. When an image in which the transmission time of the image information for one line changes drastically is subjected to decoding and printing without any measures, paper feed unevenness occurs due to the start of the paper feed motor of the recording apparatus and the braking torque.
Print quality deteriorates. Therefore, as a method of preventing the deterioration of the print quality due to the paper feed unevenness of the paper feed motor of the recording apparatus corresponding to the change of the transmission time of the image information for one line, a relatively large capacity memory is provided and transmitted. The image information is temporarily stored in a large-capacity memory, and the accumulated image information is decoded and printed at a constant speed to mitigate changes in the actual transmission speed of the image information and to prevent uneven paper feeding of the paper feed motor of the recording device. Many methods are used to prevent the deterioration of print quality due to printing.

<Problems to be Solved by the Invention> As described above, in the conventional method for preventing the deterioration of the print quality due to the paper feed unevenness of the paper feed motor of the recording apparatus, which corresponds to the change of the transmission time of the image information for one line, Since a large-capacity memory is required, not only the circuit scale of the device increases, but also the print output is delayed by the time when image information is stored in the large-capacity memory, which is different from the transmitting side (broadcasting station) There was also a problem that it was printed out at the right time.

In view of these problems, the present invention controls the decoding timing of transmitted image information and the timing to start recording the decoded pixel information in a recording device, so that the memory for one line can be used in a relatively small capacity memory. To provide a facsimile broadcast receiving apparatus which alleviates a change in transmission time of image information and which is compatible with a change in transmission time of image information for one line and in which printing quality is less deteriorated due to uneven feeding of a paper feed motor of a recording apparatus. With the goal.

<Means for Solving the Problems> The facsimile broadcast receiving apparatus of the present invention newly provides a second subcarrier in the audio frequency band of a television signal, and
A facsimile broadcast receiving apparatus that receives a facsimile broadcast signal transmitted by performing four-phase differential phase modulation on a facsimile signal composed of value information, performs a series of signal processing, and then prints it on a recording device such as a printer. At this time, a plurality of frame buffer memories 3 and 4 for temporarily storing the received facsimile signal in a frame unit, and the facsimile signal after a series of processing such as error correction are temporarily stored in a frame unit. A plurality of frame buffer memories 5 and 6 for storing, and for transferring only image information of the facsimile signals stored in the frame buffer memories 5 and 6 in frame units to the decoding unit 11 in packet units. A transfer processing unit 10 and a decoding unit 11 for decoding the facsimile image information transferred in packet units.
A control unit 9 for controlling each of the transfer processing unit 10, the decoding unit 11 and the like, and the transfer processing unit 10 to the decoding unit 11
A timing control unit 13 for controlling the timing of transferring the facsimile image information in packet units to the
Information buffer memory 12 for temporarily storing at least a plurality of lines of pixel information obtained by decoding two-dimensional or two-dimensional compression coded information, and a pixel information buffer memory
The recording start timing control unit 14 for controlling the recording start timing when recording the pixel information in line units stored in 12 at an appropriate timing, and the transfer processing unit 10 to the decoding unit 11 in packet units. For controlling the transfer timing when transferring the facsimile image information, and for controlling the recording start timing when recording the pixel information of the line unit stored in the pixel information buffer memory in the recording device.

<Operation> Suppose that the image information that needs to be decoded is stored in the frame buffer memory for temporarily storing the received facsimile signal in frame units. Data transmission rate is 16
If it is transmitted at kbps, it will take at least 577 ms until the accumulation of the frame in which the image information that requires the decoding process next is stored. Therefore, it is enough to decode the facsimile signal of 32 packets in one frame in 577 ms. If all the 32 packets in one frame are facsimile image information that requires decoding processing, the decoding processing time for one packet is It will be about 18 ms. Therefore, the control unit 9 commands the timing control unit 13 to output a facsimile image information transfer permission command every 18 ms, and outputs a transfer start command of the first packet of facsimile image information to the transfer processing unit 10. To do. Upon receiving the transfer start instruction, the transfer processing unit 10 starts transferring the facsimile image information of the first packet to the decoding unit 11. After that, the control unit 9
While confirming that the transfer processing unit 10 has finished transferring one packet of facsimile image information, the timing control unit 13
The above-mentioned processing is repeated in accordance with the facsimile image information transfer permission command from. The above-described processing is processing for relaxing the change in the transmission time of the facsimile image information in units of packets.

On the other hand, the decoding unit 11, which has received the facsimile pixel information by the transfer processing unit 10, sequentially decodes the facsimile image information and stores the decoded pixel information in the pixel information buffer memory 12
Accumulate in. When the decoding process for one line is completed, the decoding unit 11 notifies the control unit 9 that the decoding process for one line is completed. The control unit 9 which has been notified that the decoding process for one line has finished outputs a recording start command of pixel information to the recording device. At that time, the pixel information buffer memory 12 determines how many lines Make sure you have enough space. The control unit 9, which has confirmed the number of remaining lines in the pixel information buffer memory 12, has at least how long it takes for the pixel information buffer memory 12 to become full according to the number of free lines. Or calculate. Then, the calculated time constant is output to the recording start timing control unit 14 and a recording start command is output to the recording device. For example, when the pixel information buffer memory 12 has a storage capacity of 8 lines and the decoded pixel information is stored for only one line, the pixel information buffer memory 12 has a free capacity of 7 lines. . When the printing speed of one line is guaranteed to be 5 ms, it takes 35 ms before the pixel information buffer memory 12 becomes full. Therefore, the control unit 9 outputs a time constant of 35 ms to the recording start timing control unit 14 and also outputs a recording start command to the recording device. Then, even if the decoding unit 11 completes decoding of the next line, the control unit 9 records until the recording start timing control unit 14 elapses the time constant described above and outputs the recording start permission command. It does not output the next pixel information recording start command to the device. When the recording start timing control unit 14 has output the recording start permission command after the time of the above-described time value has elapsed, the control unit 9 again determines how many more lines the pixel information buffer memory 12 at that time is empty. Confirm and repeat the above process.

The above-described processing is processing for relaxing the change in the transmission time of the facsimile image information in units of lines.

As described above, the change in the transmission time of the facsimile image information is totally mitigated by appropriately adjusting the time in an appropriate unit as in the processing for reducing the change in the transmission time of the facsimile image information in the packet unit and the line unit. can do.

<Example> Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a facsimile broadcast receiving apparatus for carrying out the present invention.

In describing the details of one embodiment of the present invention, first, a schematic operation of the facsimile broadcast receiving apparatus for carrying out the present invention until extracting facsimile image information will be described.

In FIG. 1, 1 is a television broadcasting antenna, 2 is a facsimile signal reception processing unit for receiving a television broadcasting radio wave, and extracting a facsimile signal from the voice band of the television broadcasting, 3 and 4 are receiving. A frame buffer memory for storing facsimile signals in frame units, 5 and 6 frame-by-frame facsimile signals stored in the frame buffer memories 3 and 4, and a reception control unit 8 performs a series of processes such as error correction. Frame buffer memory for temporarily storing the facsimile signal after the operation, 7
Is a program selection unit for receiving a desired program or the like by a user's operation, 8 is only information on a program selected by the user from the received facsimile signals, and image information of the extracted information Only the transfer processing unit 10 decodes the decoding unit 11
A reception control unit 9 for controlling the transfer processing unit 10, a control unit 9 for controlling each unit such as the transfer processing unit 10 and the decoding unit 11,
Reference numeral 10 is a transfer processing unit for reading the facsimile image information stored in the frame buffer memories 5 and 6 in frame units in packet units and transferring it to the decoding unit 11, and 11 is transferred by the transfer processing unit 10. Decodes facsimile image information composed of two-dimensional or two-dimensional compression code,
A decoding unit for converting into image information, and 12 is a pixel information buffer memory for temporarily storing the pixel information subjected to the code conversion processing in the decoding unit 11, and in this embodiment, pixel information for eight lines is stored. It is configured so that it can be stored. Reference numeral 13 is a timing control unit for controlling the transfer timing when the transfer processing unit 10 transfers the facsimile image information stored in the frame buffer memories 5 and 6 to the decoding unit 11 on a packet basis, and 14 is a control unit 9. A recording start timing control unit for controlling the recording start timing when outputting a recording start command to the recording processing unit 15, 15 reads pixel information stored in the pixel information buffer memory 12, and a recording device (for example, A recording processing unit for recording on a thermal printer).

In the facsimile broadcast receiving apparatus having the above configuration, the television broadcast signal including the facsimile signal is received by the television broadcast antenna 1 and given to the facsimile signal reception processing section 2. The facsimile signal reception processing unit 2 to which the television broadcast signal including the facsimile signal is applied, after performing the television voice demodulation process, extracts the facsimile broadcast signal from within the voice signal band and performs a series of descrambling, deinterleaving, and the like. The processed facsimile signals are stored in the frame buffer memories 3 and 4 frame by frame. The reception control unit 8 manages which of the frame buffer memories 3 and 4 is to be stored. While one of the frame buffer memories is being used by the facsimile signal processing unit 2 for storage processing, the other frame buffer memory is being stored. The memory is configured such that the reception control unit 8 can perform error correction processing and the like (for example, while the frame buffer memory 3 is being used by the facsimile signal reception processing unit 2 for storage processing, the frame buffer memory 4 controls reception). Part 8
Is configured so that processing such as error correction can be performed. ). When the facsimile signal processing unit 2 completes the storage process of one frame of the facsimile signal, the reception control unit 8
Notify that the storage processing of one frame of the facsimile signal has been completed and prepare for the processing of the next frame. The reception control unit 8 notified by the facsimile signal processing unit 2 that the storage process of one frame of the facsimile signal has been completed is the frame for the facsimile signal reception processing unit 2 to store and process the next facsimile signal in frame units. The buffer memory is switched to a frame buffer memory different from the frame buffer memory in which the frame-based facsimile signal is previously stored, and the facsimile signals of the frame buffer memories 3 and 4 previously stored by the facsimile signal processing unit 2 are processed. Is read, and processing such as error correction is performed. Upon completion of processing such as error correction, the reception controller 8 stores the processed frame-based facsimile signal in the frame buffer memories 5 and 6. The reception control unit 8 manages which of the frame buffer memories 5 and 6 is to be stored. While the reception control unit 8 is using one of the frame buffer memories for storage processing, the other frame buffer memory is Transfer processing unit 10
Is configured so as to be able to transfer the facsimile image information in packet units to the decoding unit 11 (for example, while the reception control unit 8 is using the frame buffer memory 5 for storage processing, the frame buffer memory 6 Is the transfer processor
10 is configured so that the decoding unit 11 can perform the process of transferring the facsimile image information in units of packets). When the reception control unit 8 finishes storing the frame-by-frame facsimile signal after performing the error correction processing in the frame buffer memories 5 and 6, the reception control unit 8 performs the error correction processing from the frame buffer memories 5 and 6 again. The frame-based facsimile signal is read out and the program search processing is performed. The program search process is a desired program selected by the user in the program selection unit 7 and a frame-based facsimile after the error correction process stored in the previously read frame buffer memories 5 and 6 has been performed. Search for a match with the signal.
If the frame-by-frame facsimile signal stored in the frame buffer memories 5 and 6 is not the desired program after the error correction processing is performed, the facsimile signal reception processing unit does not process the frame buffer memory. 3,4
Then, it waits for the next frame unit facsimile signal to be stored. If the frame-based facsimile signal stored in the frame buffer memories 5 and 6 after the error correction processing is the desired program, the frame-based facsimile signal stored in the frame buffer memory 5 and 6 It is searched whether the image information is stored in. If image information is not stored in the frame-by-frame facsimile signals stored in the buffer memories 5 and 6, the facsimile signal reception processing unit 2 does not process anything in the frame buffer memories 3 and 4. It waits for the next frame unit facsimile signal to be stored. When image information is stored in the frame-by-frame facsimile signals stored in the frame buffer memories 5 and 6, all relevant packet numbers are transmitted to the control unit 9 and the control unit 9 is notified. Decode start request command is output. The above is the program search processing of the reception control unit 8, and the reception control unit 8 uses the frame buffer memories 5, 6
When the image information is stored in the frame-based facsimile signal stored in, the packet in which the decoding start request is issued to the control unit 9 and the facsimile image information that requires the decoding process is stored. The frame buffer memories 5 and 6 including the above are opened so that the transfer processing unit 10 can perform the transfer process, and the next incoming frame-based facsimile signal is processed for error correction, etc., and then subjected to error correction, etc. The frame buffer memory for storing the subsequent frame-unit facsimile signal is switched to a frame buffer memory different from the frame buffer memory opened to the transfer processing unit 10, and the facsimile signal reception processing unit 2 causes the next frame unit facsimile signal. Wait for the memory processing of to be completed.

For example, when a frame-based facsimile signal including a packet in which facsimile image information requiring decoding processing is stored is stored in the frame buffer memory 5, the reception control unit 8 causes the transfer processing unit 10 to operate in the frame buffer. The facsimile signal stored in the memory 5 is released so that it can be transferred in packet units, and the next incoming facsimile signal in frame units is subjected to error correction processing and the like. The frame buffer memory for storing the frame-based facsimile signal is switched to the frame buffer memory 6, and the facsimile signal reception processing unit 2 waits for the completion of the storage processing of the next frame-based facsimile signal.

The above is a schematic description of the operation of the facsimile broadcast receiving apparatus for extracting the facsimile image information for carrying out the present invention. Only the facsimile image information in packet units is transferred to the decoding unit 11 by the transfer processing unit 10. Is configured to be.

Next, details of the present invention will be described.

As described above, if the image information is stored in the frame-based facsimile signals stored in the frame buffer memories 5 and 6, the reception control unit 8
All the corresponding packet numbers are transmitted to the control unit 9, and a decoding start request command is output to the control unit 9. The control unit 9 provides a decoding start request command from the reception control unit 8 and all packet number information that requires decoding processing in the frame-based facsimile signal, and requires decoding processing in the frame-based facsimile signal. It recognizes how many packets there are and calculates how long it takes to decode one packet. For example, when the control unit 9 receives a decoding start request command from the reception control unit 8, all the packets in the frame-based facsimile signal require a decoding process (facsimile image information is stored in all the packets. ), The number of packets that need decoding processing in the frame-based facsimile signal is 32 packets. It takes at least 577 ms until the facsimile signal reception processing section 2 receives and stores the next frame-based facsimile signal and the storage processing, and the reception control section 8 finishes processing such as error correction and program search processing. Therefore, the decoding process for one frame is 577ms
If the number of packets that need to be decoded in the frame-based facsimile signal is 32, it takes only 18 ms to decode one packet of facsimile image information. become. 1
The control unit 9 that has finished calculating how long it takes to process the packet decoding process outputs the calculated time constant to the timing control unit 13 and passes the time corresponding to the output time constant. The timing control unit 13 is set to output a facsimile image information transfer permission command every 18 ms (in each example), and at the same time, the transfer processing unit 10 decodes the frame-based facsimile signal received from the reception control unit 8. According to the packet number that needs to be processed, a transfer start command is output to start the transfer processing (in the example, the control unit 9 starts transfer to the transfer processing unit 10 so as to transfer the facsimile image information of the first packet). Output a command). The transfer processing unit 10 that has received the transfer start instruction to start the transfer processing according to the packet number that requires the decoding processing in the frame-based facsimile signal is a packet that requires the decoding processing in the frame-based facsimile signal. According to the number, transfer processing of the facsimile image information in packet units is started to the decoding unit 11. Thereafter, the control unit 9 repeats the above-described processing according to the facsimile image information transfer permission command from the timing control unit 13 while confirming that the transfer processing unit 10 has transferred one packet of facsimile image information.

On the other hand, the decoding unit 11 to which the packet-based facsimile image information has been transferred by the transfer processing unit 10 sequentially decodes the transferred packet-based facsimile image information, and stores the decoded pixel information in the pixel information buffer memory 12. .
When the decoding unit 11 completes the decoding and storage processing for one line,
The control unit 9 is notified that the decoding and storage processing for one line has been completed. When the control unit 9 is informed that the decoding and storage processing for one line has been completed, it outputs a recording start command to the recording processing unit 15. At that time, the number of additional lines in the pixel information buffer memory 12 is increased. Make sure it is free. Then, the control unit 9 confirming how many more lines are empty in the pixel information buffer memory 12 has a minimum amount of time until the pixel information buffer memory 12 is full according to the number of empty lines. Or calculate. For example, it is assumed that the decoding unit 11 has completed the decoding and storage processing of the facsimile image information for one line and the pixel information buffer memory 12 stores the pixel information for one line. Pixel information buffer memory 12 of this embodiment
Since it is configured to store pixel information for 8 lines, the pixel information buffer memory 12 has an empty area for 7 more lines, and the printing speed for 1 line is
If 5 ms is guaranteed, there is at least 35 ms before the pixel information buffer memory 12 becomes full. The control unit 9 that has finished calculating at least how long it will take to fill the pixel information buffer memory 12 will output the time constant to the recording start timing control unit 14, and the recording start timing of the next line. Is set so that the recording start permission command is not output until the time corresponding to the above time constant has elapsed, and for the recording processing unit 15,
Outputs a recording start command. Upon receiving the recording start command, the recording processing unit 15 reads the pixel information from the pixel information buffer memory 12 and records it in the recording device. And the control unit 9
Even if the decoding unit 11 completes the decoding and recording process for the next one line, until the recording start timing control unit 14 elapses the time corresponding to the above-mentioned time constant and the recording start permission command is output, The recording start command for the line is not output to the recording processing unit 15. When the recording start timing control unit 14 has passed the time of the above-mentioned time constant and the recording start permission command is output, the control unit 9 again determines how many lines are empty in the pixel information buffer memory 12 at that time. Confirm and repeat the above process.

<Effects of the Invention> As described above, according to the facsimile broadcast receiving apparatus of the present invention, the facsimile image information for one line is transmitted by controlling the decoding timing and the recording timing in the small capacity buffer memory. Even if the time fluctuates drastically, it can be alleviated, and a good printing result can be obtained without causing the deterioration of the printing quality due to the unevenness of the paper feeding of the paper feeding motor of the recording apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram of a facsimile broadcast receiving apparatus of the present invention, and FIG. 2 is a configuration diagram showing a frame configuration of a facsimile signal according to the present invention. 2 ... Facsimile signal reception processing unit, 3,4,5,6 ... Frame buffer memory, 7 ... Program control unit, 8 ... Reception control unit, 9 ... Control unit, 10 ... Transfer processing unit, 11 ...... Decoding unit, 12 ... Pixel information buffer memory, 13 ... Timing control unit, 14 ... Recording start timing control unit, 15 ... Recording processing unit.

Claims (1)

[Claims] 1. A second subcarrier is newly provided in an audio frequency band of a television signal, and a facsimile signal composed of binary information is subjected to 4-phase differential phase modulation to receive a transmitted facsimile broadcast signal. In a facsimile broadcast receiving apparatus that prints on a recording device such as a printer after performing a series of signal processing, a plurality of frame buffer memories 3 for temporarily storing received facsimile signals in frame units, 4,
And a plurality of frame buffer memories 5 and 6 for temporarily storing a facsimile signal after a series of processing such as error correction is performed in a frame unit, and stored in the frame buffer memories 5 and 6 in a frame unit. The transfer processing unit 10 for transferring only the image information of the facsimile signal in the packet unit to the decoding unit 11, the decoding unit 11 for decoding the facsimile image information transferred in the packet unit, and the transfer A control unit 9 for controlling each unit such as the processing unit 10 and the decoding unit 11, and a timing control for controlling the timing when the facsimile image information is transferred in packet units from the transfer processing unit 10 to the decoding unit 11. And a buffer unit for pixel information for temporarily storing at least a plurality of lines of pixel information obtained by decoding one-dimensional or two-dimensional compression coded information. A memory 12 and a recording start timing control unit 14 for controlling a recording start timing when recording the pixel information in line units stored in the pixel information buffer memory 12 at an appropriate timing, 1 A facsimile broadcast receiving apparatus characterized in that it is possible to obtain good print quality with a buffer memory having a small capacity as much as possible even if the time when the facsimile image information for a line is transmitted changes.