JPS6348950A - Facsimile broadcast reception equipment - Google Patents

Abstract

PURPOSE:To reduce the deterioration of picture quality due to the deterioration in the reception state by recording a picture signal received at the just preceding normal state again if the detection of a synchronizing signal is disabled. CONSTITUTION:If no synchronizing signal is detected by a detection circuit 1, the picture signal for one line at that time is not written in a memory 4. On the other hand, a recording circuit 3 is activated according to the synchronizing signal generated by a timer circuit 5 to record a picture signal read from the memory 4. The picture signal is a picture signal at one preceding line and recorded again.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a facsimile broadcast receiving apparatus that multiplexes and broadcasts facsimile equipment onto television radio waves.

Prior art FIG. 2 shows a conventional configuration of a facsimile broadcast receiving apparatus. The facsimile broadcast signal (hereinafter referred to as FAX signal) separated and extracted from the television radio waves is sent to the synchronization signal detection circuit 1 and A.
/D conversion circuit 2.

As shown in FIG. 3, the FAX' signal includes one line of analog image signal between the pulses of the synchronizing signal a having a constant period. The detection circuit 1 receives a synchronization signal a from the FAX signal.
The A/D conversion circuit 2 converts the FAX signal into a digital image signal.

In response to the synchronization signal from the detection circuit 1, the recording circuit 3
A digital image signal from the A/D conversion circuit 2 is recorded on recording paper as a one-line image.

In this way, image signals are recorded in synchronization line by line using the synchronization signal.

Problems to be Solved by the Invention In the case of a facsimile broadcast receiving device, unlike a normal facsimile device, there is a major problem in that the reception condition easily fluctuates depending on the propagation condition of radio waves.

If the detection circuit 1 does not detect the synchronizing signal due to radio wave disturbance or the like, the recording circuit 3 will not perform any recording operation, and the image of that line will be completely missing.

In order to eliminate this recording omission, the following techniques have been proposed. If a synchronization signal cannot be detected from the FAX signal, the receiving side compensates for the missing synchronization signal and generates a synchronization signal with a constant period.

If the recording circuit is operated using this interpolated synchronization signal, recording omissions will be eliminated.

However, the fact that the synchronization signal cannot be detected means that the FAX
This means that the signal is highly distorted.

Therefore, the image signal at that time is significantly distorted, and even if it is forcibly recorded, a good image cannot be obtained, and the resulting quality is not much different from that in the case of recording omission.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to provide a facsimile machine that can obtain a good recorded image even when the reception condition is so bad that the synchronization signal cannot be detected. An object of the present invention is to provide a broadcast receiving device.

Means for Solving the Problems Therefore, in the present invention, the synchronization signal detecting means separates the synchronization signal from the FAX signal, and even if the synchronization signal cannot be detected, it is compensated for and a synchronization signal of a constant period is generated. The synchronization signal interpolation means that generates the gold film.

Further, the image signal is transmitted to the recording means via the temporary storage means. Then, in response to a synchronization signal being detected by the detection means, an image signal is written into the temporary storage means, and an image signal is written from the temporary storage means to the recording means in response to a synchronization signal from the interpolation means. The configuration is such that the signal can be read out.

Effect: When the synchronization signal is not detected by the detection means, both signals, which may be greatly distorted at that time, are not written into the temporary storage means. Therefore, the image signal of one line before remains in the temporary storage means. This image signal from one rhino before is recorded by the recording means in response to the interpolated synchronization signal.

Embodiment FIG. 1 shows a schematic configuration of a facsimile broadcast receiving apparatus according to an embodiment of the present invention.

Similar to the conventional device, a FAX signal separated from television radio waves is input to a synchronization signal detection circuit 1 and an A/D conversion circuit 2, and a shaped synchronization signal and a digital image signal are output from each.

The digital image signal from the A/D conversion circuit 2 is written into the -degree memory circuit 4, and then read out to the recording circuit 3 and recorded.

The timer circuit 5 functions as the above-mentioned synchronization signal interpolation means and also controls writing/reading of the memory circuit 4. That is, when the synchronization signal detected by the detection circuit 1 is input t'', the memory circuit 4 is put into the write mode at a predetermined timing, and one line of digital image signal output from the A/D conversion circuit 2 is transferred to the memory. Write to circuit 4.Also, even if the detection circuit 1 cannot detect the synchronization signal that is supposed to be generated at a constant period, the timer circuit 5 generates a synchronization signal with no missing constant period, and the synchronization Based on the signal, the memory circuit 4 is put into the read mode at a predetermined timing, and at the same time, the synchronization signal is applied to the recording circuit 3. In response, the recording circuit 3
The digital image signal for one line read from is recorded on recording paper.

In the above configuration, the detection circuit 1
If the synchronization signal is not detected at that time, the image signal for one line at that time is not written into the memory circuit 4. However, the recording circuit 3 operates according to the synchronization signal generated by the timer circuit 5 and records the image signal read out from the memory circuit 4. This image signal is an image signal from one line/previous.

However, if the synchronization signal cannot be detected, the image signal of the previous line is recorded again. As a result, a better image can be obtained than in the conventional method where recording is omitted or a highly distorted image signal is forcibly recorded. In addition, although the A/D conversion circuit and the digital memory were used in the above embodiment, it goes without saying that an analog memory may also be used.

Effects of the Invention As explained in detail above, in the facsimile broadcast receiving apparatus according to the present invention, when a synchronization signal is not detected due to disturbances in the radio wave condition, the image that was normally received immediately before is used. Since the signal is recorded again, there is relatively little deterioration in received image quality due to deterioration in reception conditions.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a facsimile broadcast receiving device according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of a conventional facsimile broadcast receiving device, and FIG. 3 is a waveform showing an example of a facsimile broadcast signal and a synchronization signal. It is a diagram. 1... Synchronization signal detection circuit, 2... A/D conversion circuit,
3... Recording circuit, 4... Memory circuit, 5... Timer circuit. Name of agent: Patent attorney Uneo Nakao and one other person 9 mil.

Claims (1)

[Claims] a synchronization signal detection means for separating a synchronization signal from a facsimile broadcast signal; a synchronization signal interpolation means for generating a synchronization signal of a constant period by compensating for the absence of a synchronization signal in the output of the detection means; temporary storage means into which the image signal is written in response to the detection of a synchronization signal by the means; and recording means for reading and recording the image signal from the temporary storage means in response to the synchronization signal from the synchronization signal interpolation means. A facsimile broadcast receiving device comprising means.