JPH06215480A - Signal witching device - Google Patents

Abstract

PURPOSE:To attain switching a regenerative audio signal and a video signal, etc., in plural VTRs according to the height in the error rate of the digital VTR. CONSTITUTION:The error rate signals 109, 110, 111, 112 are outputted separately in the audio signal and the video signal at the time of reproducing the digital VTR. When tapes recording the same information are loaded on plural VTRs 101, 102, and these VTRs 101, 102 are reproduced at the same timing, the audio signal 107, the video signal 108 with the lowest error rates in the same information are detected by comparators 103, 104. Thus, the audio signal 107 and the video signal 108 with respective lowest error rates are selected and outputted by an audio switcher 105, a video switcher 106. At this time, the control signals 113, 114 from the comparators 103, 104 are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal switching device in a broadcasting station transmitting device, for example.

[0002]

2. Description of the Related Art A conventional signal switching device is, for example, a dropout compensator.

FIG. 4 shows a block diagram of this conventional signal switching device. In FIG. 4, 41 is an analog video tape recorder (hereinafter abbreviated as VTR), 42 is a time delay device, 43 is a 2-input 1-output video switcher, and 44 is RF detection for detecting a high-frequency signal reproduced from the head of the analog VTR. It is a device.

The operation of the conventional signal switching device configured as described above will be described below.

Normally, the video signal 45 from the analog VTR 41 is directly output via the video switcher 43. In this case, the signal level of the RF signal 48 output from the analog VTR 41 is normal, and the RF detection device 44 determines its state and controls the selection path of the video switcher 43.

However, the RF detector 48 detects the signal level of the RF signal 48 output from the analog VTR 41.
If the signal level is low, the switching signal 49 of the video switcher 43 is selected so that the video switcher 43 selects the video signal 46 from the time delay device 42.
Is controlled. The time delay amount of the time delay device 42 is one horizontal scanning period, one field period or one frame period.

That is, if a normal RF signal is not detected, the screen portion (or pixel) is replaced with another screen portion having the highest correlation to reduce the deterioration of image quality.

FIG. 5 shows an example of the switching timing of the video signal 45 from the analog VTR 41 and the video signal 46 that has passed through the time delay device 42.

In FIG. 5, the RF detector 44 outputs "H" when the level of the RF signal 48 from the analog VTR 41 is normal, and otherwise outputs "L". The output signal 47 of the video switcher 43 is switched according to the output of the RF detection device 44.

[0010]

However, in the above configuration, when a normal RF signal is not detected, the screen portion is not changed to the correct screen but to another screen portion closest to the screen. Since the screen is replaced, it differs from the original screen, which causes deterioration of image quality.

There is also a dropout compensator using a pre-hold which is the same method for audio signals, but in this case as well, the sound quality is degraded because it is different from the original signal.

In view of the above point, the present invention has an object to provide a signal switching device which does not deteriorate by switching using an error rate signal.

[0013]

SUMMARY OF THE INVENTION The present invention is directed to an error rate comparator for comparing the level of each error rate output from a plurality of digital information recording / reproducing apparatuses, and a reproduction output from the plurality of digital information recording / reproducing apparatuses. A signal switching device comprising signal switching means for switching a signal according to a selection signal from the error rate comparator.

[0014]

According to the present invention, the reproduction output signal corresponding to the lowest error rate among the reproduction outputs of each digital information recording / reproducing apparatus is selected by the above-mentioned structure.

[0015]

1 is a block diagram of a signal switching device according to an embodiment of the present invention.

In FIG. 1, 101 and 102 are digital VTRs, 103 is an audio error rate comparator, and 10
4 is a video error rate comparator, 105 is an audio switcher, and 106 is a video switcher.

The operation of the signal switching device of the present embodiment constructed as above will be described below.

From the digital VTRs 101 and 102, the audio error rate signals 109 and 1 are separately provided during reproduction.
10. Video error rate signals 111 and 112 are output. A medium on which the same information is recorded is put in the digital VTRs 101, 102, and these digital VTRs 101, 1
When 02 is reproduced at the same timing, the audio signal and the video signal having the lowest error rate in the same output information are respectively detected by the audio error rate comparator 10.
3. Detected by the video error rate comparator 104.

That is, the audio error rate comparator 10
3 output signal 113, video error rate comparator 104
The output signal 114 of 1 indicates the digital VTR having the lowest error rate in each audio and video signal.

The output signals 113 and 114 are transmitted to the audio switcher 105 and the video switcher 106.
, And the audio signal 107 and the video signal 108 having the lowest error rate are selectively output from each switcher.

FIG. 2 shows an example of a switching timing chart regarding a video signal of the signal switching device according to the embodiment of the present invention.

The level of the video error rate signal 111 of the digital VTR 101 and the level of the video error rate signal 112 of the digital VTR 102 are monitored. Then, signal selection is made by "H" and "L" of the output signal 114 from the video error rate comparator 104.

As is apparent from FIG. 2, it can be seen that the video output signal from the digital VTR having the lower video error rate is selected.

In this embodiment, the digital VTR 10 is used.
Although the error rate from 1 and 102 is dealt with, it is not limited to the digital VTR, and any type such as DAT may be used as long as the error rate is output. Further, although the audio signal and the video signal are handled in the present embodiment, the present invention is not limited to these signals, and any signal may be used as long as it corresponds to the output error rate signal. For example, a data access error rate of an information retrieval device or the like can be considered.

FIG. 3 shows a block diagram of the second signal switching device of the present invention. The difference from FIG. 1 is that delay units 301 and 3 are provided between the digital VTRs 101 and 102 and the audio switchers and video switchers 105 and 106.
02, 303, 304 are provided, and audio error rate comparators, video error rate comparators 103, 104 and audio switchers, video switchers 105, 106 are provided.
That is, the delay units 305 and 306 are provided between and.

The delay times of the delay units 305, 301 and 302 are adjusted so that the output signal 113 from the audio error rate comparator 103 and the audio output signals from the digital VTRs 101 and 102 are matched in timing.

Similarly, the video error rate comparator 104
Output signal 114 from the digital VTR 101, 102
The delay times of the delay units 306, 303, 304 are adjusted so that the timings of the video output signals from the.

By introducing the delay unit, accurate signal switching control can be performed. Although the audio output signal and the video output signal are switched based on their respective error rates in the first and second embodiments, they may be carried out by the audio alone or the video alone. The present invention is also effective when there are three or more digital VTRs. Furthermore, the present invention is effective even for a configuration that does not include a digital VTR and that performs processing by receiving an error rate signal and a reproduction signal from the digital VTR.

[0029]

As described above, according to the present invention, by using a plurality of digital information recording / reproducing devices, it is possible to select an audio signal or a video signal having a low error rate and therefore the highest sound quality and image quality. it can.

Further, by detecting the error rate of each of the audio signal and the video signal separately, as long as the audio and video signals of all the plurality of digital information recording / reproducing devices are not deteriorated, a good quality audio signal or video signal can be obtained. You can choose.

Therefore, its practical effect is great.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a signal switching device according to an embodiment of the present invention.

FIG. 2 is a timing chart of the embodiment.

FIG. 3 is a block configuration diagram of a signal switching device according to another embodiment of the present invention.

FIG. 4 is a block configuration diagram of a conventional signal switching device.

FIG. 5 is a timing chart of the conventional example.

[Explanation of symbols]

 101,102 Digital VTR 103 Audio error rate comparator 104 Video error rate comparator 105 Audio switcher 106 Video switcher 301-306 Delay unit

Claims (12)

[Claims] 1. A plurality of digital information recording / reproducing devices having an error rate output means for outputting an error rate (error rate of a reproduction signal) and a reproduction signal output means for outputting a reproduction signal, and a comparison of each of the error rates. A signal switching device comprising an error rate comparator for outputting a selection signal for selecting a reproduction output signal corresponding to the lowest error rate, and signal switching means for switching each reproduction signal by the selection signal. 2. A plurality of digital information recording / reproducing devices are capable of recording / reproducing an audio signal and a video signal, and an audio error rate output means for outputting an audio error rate, and a video error rate output means for outputting a video error rate. An audio reproduction signal output means for outputting an audio reproduction signal and a video reproduction signal output means for outputting a video reproduction signal, wherein an error rate comparator compares the high and low of each of the audio error rates with the lowest error rate. While outputting an audio selection signal for selecting an audio reproduction signal corresponding to, comparing the high and low of each video error rate, and outputting a video selection signal for selecting a video reproduction signal corresponding to the lowest error rate, The switching means outputs the audio reproduction signals to the audio signals. While switching by the selection signal,
The signal switching device according to claim 1, wherein each of the video reproduction signals is switched by the video selection signal. 3. A first delay means for delaying each reproduction signal, wherein the output signal of the first delay means is switched by a signal switching means. 2. The signal switching device according to any one of 2. 4. The signal switching device according to claim 3, wherein the delay time of the first delay means is variable. 5. A second delay unit for delaying a selection signal, wherein the signal switching unit is switched by the output of the second delay unit. The signal switching device according to any one of the claims. 6. The signal switching device according to claim 5, wherein the delay time of the second delay means is variable. 7. The level of each error rate output from a plurality of digital information recording / reproducing apparatuses having an error rate output means for outputting an error rate (error rate of a reproduced signal) and a reproduced signal output means for outputting a reproduced signal. A signal switching device comprising an error rate comparator for outputting a selection signal for selecting a reproduction output signal corresponding to the lowest error rate by comparison, and a signal switching means for switching each reproduction signal by the selection signal. . 8. A plurality of digital information recording / reproducing devices are capable of recording / reproducing an audio signal and a video signal, and an audio error rate output means for outputting an audio error rate, and a video error rate output means for outputting a video error rate. An audio reproduction signal output means for outputting an audio reproduction signal and a video reproduction signal output means for outputting a video reproduction signal, wherein an error rate comparator compares the high and low of each of the audio error rates with the lowest error rate. While outputting an audio selection signal for selecting an audio reproduction signal corresponding to, comparing the high and low of each video error rate, and outputting a video selection signal for selecting a video reproduction signal corresponding to the lowest error rate, The switching means outputs the audio reproduction signals to the audio signals. While switching by the selection signal,
8. The signal switching device according to claim 7, wherein each of the video reproduction signals is switched by the video selection signal. 9. The method according to claim 7, further comprising a first delay means for delaying each reproduction signal, and an output signal of the first delay means is switched by a signal switching means. 8. The signal switching device according to any one of 8. 10. The signal switching device according to claim 9, wherein the delay time of the first delay means is variable. 11. The method according to claim 7, further comprising a second delay means for delaying the selection signal, wherein the signal switching means is switched by the output of the second delay means. The signal switching device according to any one of the claims. 12. The signal switching device according to claim 11, wherein the delay time of the second delay means is variable.