JP3076584B2 - Truck identification device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track discriminating apparatus suitable for use in, for example, an apparatus for reproducing a video floppy.

[Prior Art] In an electronic still video camera, not only can a video signal be recorded on a video floppy,
An audio signal can be recorded as needed.

FIG. 6 is a block diagram showing an example of the configuration of a conventional track discriminating apparatus for such a video floppy.

The signal reproduced by the head 1 is a reproduction amplifier (PB AM
P) After being amplified by 2, high-pass filter and equalizer (HPF & EQ) 3, low-pass filter (LPF)
4 and a band pass filter (BPF) 5.

The high-pass filter and equalizer 3 separates and equalizes high-frequency components of the input signal, and outputs the same to the luminance signal demodulation circuit 6. The luminance signal demodulation circuit 6 FM-demodulates the input signal and outputs the result to the luminance signal processing circuit 10 and the audio signal processing circuit 9. The luminance signal processing circuit 10 processes the input demodulated luminance signal and outputs the processed signal to the adder 13. The audio signal processing circuit 9 processes the input demodulated audio signal and outputs the processed signal to a circuit (not shown) via the switch 14.

The audio signal includes a flag indicating a start or an end and various control codes. When the audio signal processing circuit 9 detects these flags and control codes, the detection result is transmitted to the CPU 1.
Output to 2.

The low-pass filter 4 separates a low-frequency component (FM color signal component) from the input signal and outputs it to the color signal demodulation circuit 7. The color signal demodulation circuit 7 demodulates the input FM color signal,
The demodulated output is output to the color signal processing circuit 11. The color signal processing circuit 11 processes the input demodulated color signal and outputs it to the adder 13.

Further, the band pass filter 5 separates a signal (ID signal) of a predetermined frequency band from the input signal and outputs the signal to the ID demodulation circuit 8. The ID demodulation circuit 8 demodulates the ID signal and outputs the demodulation result as a CP.
Output to U12. The CPU 12 generates a character signal or the like corresponding to the ID signal as necessary, and outputs it to the adder 13.

The adder 13 adds the video signals from the luminance signal processing circuit 10, the color signal processing circuit 11, and the CPU 12, and outputs the result to a circuit (not shown) via the switch 14.

Further, the CPU 12 controls the switch 14 according to a flowchart as shown in FIG.

That is, when reproducing a video floppy (not shown) by the head 1 (step S1), the CPU 12 determines the presence or absence of an ID from the output of the ID signal demodulation circuit 8 (step S1).
2). Since the ID (DPSK) signal is recorded on the video track (the track on which the video signal is recorded), detection of this ID means that the reproduction track is a video track. Therefore, at this time,
Opens the upper contact of the switch 14 in the figure and mutes the audio output (step S4).

On the other hand, when the reproduction track is an audio track, a flag or a control code is recorded therein. Therefore, when these flags or control codes are detected, the reproduction track is an audio track, so that the CPU 12 opens the lower contact in the figure of the switch 14 and mutes the video signal as opposed to step S4. (Steps S3, S5).

In this way, a correct reproduction signal is automatically selected and output regardless of whether the reproduction track is a video track or an audio track.

[Problems to be Solved by the Invention] The conventional device determines the video track or the audio track from the presence or absence of a flag or a control code included in the audio track or the presence or absence of an ID signal in the video track. I do it. As a result, when an error occurs in the reading operation, there is a possibility that the reproduction track is erroneously detected. Also, it had to have an audio signal processing circuit and an ID signal demodulation circuit.

The present invention has been made in view of such a situation, and is not affected by a reading operation, and has an audio signal processing circuit and
Even if an ID signal demodulation circuit is not provided, it is possible to accurately detect a reproduction track.

[Means for Solving the Problems] The track discriminating apparatus of the present invention has recorded thereon a video track including a video signal including a color signal and a luminance signal, and an audio track including a plurality of sectors and including an audio signal. A track discriminating device for discriminating between the video track and the audio track on a disc, a reproducing unit for reproducing a video signal and an audio signal from the video track and the audio track, and the luminance signal and the audio from the output of the reproducing unit. Signal processing means for separating and demodulating a signal including a signal, and separating a vertical synchronization signal from the luminance signal,
And a synchronization separation unit for determining and separating a pulse indicating the flag between the sectors of the audio track as a vertical synchronization signal from at least the audio signal, a detection unit for detecting one rotation of the disk, and a rotation of the disk for one rotation. Counting the number of outputs of the synchronization separation means during the period of
Determining means for determining the audio track or the video track from the count value.

[Operation] In the track discriminating apparatus having the above configuration, when a video track is reproduced by the reproducing means, the synchronization separating means separates and outputs one vertical synchronization signal from the luminance signal for each rotation of the disk. When an audio track is reproduced by the reproducing means, the synchronization separating means determines a plurality of pulses included in the audio signal as a vertical synchronizing signal for each rotation of the disk and outputs this vertical synchronizing signal.
Therefore, the discriminating means can discriminate the audio track or the video track based on the number of vertical synchronizing signals output from the sync separating means for each rotation of the disk.

Therefore, unlike the conventional device, the audio signal processing circuit does not determine the audio track or the video track based on the detection of the flag or control code by the audio signal processing circuit or the detection of the ID signal by the ID signal demodulation circuit. And the detection operation (read operation) of the ID signal demodulation circuit is not affected by the error, and the track discriminating device does not need to have an audio signal processing circuit and an ID signal demodulation circuit.

[Embodiment] FIG. 1 is a block diagram showing a configuration of an embodiment of a track discriminating apparatus according to the present invention, and portions corresponding to those in FIG. 6 are denoted by the same reference numerals. It will be omitted as appropriate because it will be repeated.

In this embodiment, the disk 21 is rotated by the motor 22. The rotation of the disk 21 is detected by the PG detector 23 (detection means).
Is detected as a PG pulse, and the detection result PG
The pulse is output to the CPU 12 (determination means). Also,
As in the conventional device, the signal reproduced by the head 1 (reproducing means) is amplified by the reproducing amplifier 2, and then input to the high-pass filter and equalizer 3 (signal processing means), the low-pass filter 4, and the band-pass filter 5. Is done.

The signal reproduced by the head 1 is separated into a signal including an audio signal and a luminance signal by a high-pass filter and an equalizer 3 and then FM-demodulated by a luminance signal demodulation circuit 6 (signal processing means). (Signal processing means) to process and output.

A part of the output of the luminance signal processing circuit 10 (a signal including an audio signal or a luminance signal) is supplied to a synchronization separation circuit 24 (synchronization separation means), and is output from the luminance signal among the signals including the audio signal or the luminance signal. The vertical synchronizing signal is separated.

A part of the output of the luminance signal processing circuit 10 (a signal including an audio signal or a luminance signal) is supplied to an audio signal processing circuit 9 where the audio signal of the audio signal or the signal including the luminance signal is processed. It has become so. The output of the synchronization separation circuit 24 is supplied to the CPU 12.

 Other configurations are the same as those in FIG.

Next, the operation will be described with reference to the flowchart of FIG.

The disk 21 is rotated by a motor 22, and the head 1 (reproducing means) reproduces the disk 21. Thus, as in the case described above, if the reproduction track is an audio track, an audio signal is output from the audio signal processing circuit 9 (audio signal processing means). The video signal processed by the signal processing circuit 11 is output from the adder 13.

The CPU 12 monitors the PG output of the PG detector 23 and
One rotation of 1 is detected (step S11). When the PG pulse is detected, the CPU 12 sets the variable N to 0 (Step S12). Next, before the PG pulse arrives again (until the disk 21 makes one rotation), the synchronization separation circuit
When 24 generates the detection signal of the vertical synchronization signal, the variable N is incremented by 1 (steps S13, S17, S18).

When the currently reproduced track is a video track, the luminance signal processing circuit 10 outputs a luminance signal as shown in FIG. 3A. Accordingly, the sync separation circuit 24 outputs a sync separation output as shown in FIG. 3B once during one rotation of the disk 21.

When the playback track is an audio track, the audio signal is recorded in a plurality of sectors, in this example, four sectors, as shown in FIG. Accordingly, in this case, in the output of the luminance signal processing circuit 10, as shown in FIG. 3C, in addition to the original audio signal component, a pulse that changes between a low level and a high level occurs at the boundary of each sector. . The pulse corresponds to a start flag or an end flag indicating the start or end of recording of an audio signal in a sector.

Here, the synchronization separation circuit 24 is configured to detect a pulse that changes to a low level among the pulses included in the input audio signal, similarly to the synchronization signal included in the luminance signal described above. I have. That is, the sync separation circuit 24
Is configured to output a synchronization signal in response to the pulse that changes to the low level, similarly to the case where the synchronization signal is separated from the luminance signal and output.

Therefore, when the pulse that changes to a low level among the pulses included in the audio signal is input, the synchronization separation circuit 24 compares the pulse that changes to the low level with the case of the synchronization signal included in the luminance signal described above. Similarly, detection is performed, and a synchronization signal is output in response to the low level pulse. In other words, the synchronization separation circuit 24 determines the pulse that changes to the low level as a synchronization signal, and outputs this synchronization signal.

Therefore, as shown in FIG. 3D, the sync separation circuit 24 corresponds to each flag corresponding to the boundary between four sectors included in the audio signal, that is, each pulse corresponding to each rotation of the disk 21. And outputs a synchronization signal four times.

The above is the case where the audio signal of a sufficient volume is recorded in all four sectors. However, if the audio signal of a sufficient volume is recorded in 3.5 sectors, the luminance signal processing circuit 10
3 and the output of the sync separation circuit 24 are as shown in FIGS. Similarly, the output of the luminance signal processing circuit 10 and the output of the sync separation circuit 24 are output when a low-level audio signal is recorded in 1.5 sectors or 0.5 sectors, or when almost no audio signal is recorded. , 3G to 3L, respectively.

That is, in any case, if the disk 21 is an audio track, that is, a track on which an audio signal is recorded even a little, the sync separation circuit 24 sets the disk 21 to one.
During rotation, at least four synchronization signals (detection signals)
Is output.

When one track is divided into N (N is a natural number of 2 or more), the sync separation circuit 24
Of course, during one rotation, at least N synchronization signals (detection signals) are output.

Therefore, the CPU 12 checks the value of the variable N when the disk 21 makes one rotation (steps S13 and S14), and determines that the reproduction track is an audio track when the variable N is 2 or more.
The lower contact in the figure of the switch 14 is turned off to mute the video signal (steps S14 and S15). When the variable N is 1 or less, the reproduction track is determined to be a video track,
The upper contact in the figure of the switch 14 is turned off to mute the audio signal (steps S14 and S16).

FIG. 5 is a flowchart showing another processing step of the track discriminating apparatus of the present invention.

In this embodiment, when a PG pulse is detected (step
21) If the output of the sync separation circuit 24 is not detected until the next PG pulse is detected (the disk 21 makes one rotation), or if it is detected once, the playback track is the video track. Is determined (steps S22, S24, S25, S23).
When the output of the sync separation circuit 24 is detected twice, it is determined that the track is an audio track (steps S25 to S27).

In the above description, the sync separation circuit 24 is provided separately from the luminance signal processing circuit 10, but a circuit built in the luminance signal processing circuit 10 may be used.

[Effects of the Invention] As described above, when a video track is reproduced by the reproduction means, the synchronization separation means separates one vertical synchronization signal from the luminance signal for each rotation of the disk and outputs it.
When an audio track is reproduced by the reproduction means, the synchronization separation means determines a plurality of pulses included in the audio signal as a vertical synchronization signal for each rotation of the disk, and outputs this vertical synchronization signal. Therefore, the determination means
An audio track or a video track can be determined based on the number of vertical synchronizing signals output from the synchronizing separation means for each rotation of the disk.

Therefore, unlike the conventional device, the audio signal processing circuit does not determine the audio track or the video track based on the detection of the flag or control code by the audio signal processing circuit or the detection of the ID signal by the ID signal demodulation circuit. And the detection operation (read operation) of the ID signal demodulation circuit is not affected by the error, and the track discriminating device does not need to have an audio signal processing circuit and an ID signal demodulation circuit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a track discriminating apparatus according to the present invention, FIGS. 2 and 5 are flowcharts for explaining the operation of the embodiment of FIG. 1, and FIG. FIG. 4 is a waveform diagram of the output of the luminance signal processing circuit and the sync separation circuit in the embodiment of FIG. 4, FIG. 4 is an explanatory diagram of a sector of the disk used in the embodiment of FIG. 1, and FIG. FIG. 7 is a flow chart for explaining the operation of the example of FIG. 1 ... head (reproducing means), 3 ... high-pass filter and equalizer (signal processing means), 6 ... luminance signal demodulation circuit (signal processing means), 7 ... color signal demodulation circuit, 8 ...
ID signal demodulation circuit, 9 audio signal processing circuit, 10 luminance signal processing circuit (signal processing circuit), 11 color signal processing circuit, 12 CPU, 23 PG detector (detection means), twenty four……
Sync separation circuit (sync separation means).

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/781 H04N 5/91-5/956 G11B 20/02

Claims (1)

(57) [Claims] A discriminating means for discriminating between the video track and the audio track on a disk on which a video track including a video signal including a color signal and a luminance signal and an audio track including a plurality of sectors and including an audio signal are recorded. A reproducing unit that reproduces a video signal and an audio signal from the video track and the audio track; and a signal that separates and demodulates a signal including the luminance signal and the audio signal from an output of the reproducing unit and processes the signal. Processing means; a synchronization separation means for separating a vertical synchronization signal from the luminance signal, and judging and separating at least a pulse indicating a flag between the sectors of the audio track from the audio signal as a vertical synchronization signal; Detection means for detecting one rotation of the disk, and output of the synchronization separation means during a period when the disk makes one rotation. The number was counted, track discrimination device characterized by comprising: a discriminating means for discriminating the audio track or video track from the count value, a.