JPH04117655A - Self-recording and reproduction discriminating device - Google Patents

Abstract

PURPOSE:To easily judge whether tracking data after the completion of the operation of an autotracking are self-recorded and reproduced or not by judging that the data are self-recorded and reproduced when the data are within a prescribed range from standard tracking data. CONSTITUTION:A microcomputer 10 detects the rise of RF switching RFSW signals to control the switchover of a head for a video, inputs the output of an envelope detecting circuit 8 after A-D converting it, and repeats this at a prescribed sampling interval. Then, the entire sampling values in one field period are added, and a value N corresponding to the present envelope can be obtained. At that time, when the tracking adjustment is not completed, the microcomputer is controlled so that the maximum value of this envelope can be searched, and the adjusting operation is completed when it is judged to be the maximum value. Then, when the tracking data N corresponding to the maximum value of the envelope is within the prescribed range from standard tracking data S, the data are judged to be self-recorded and reproduced. Thus, it is possible to easily judge that the data are self-recorded and reproduced or not.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a self-recording/reproduction determination device for a VTR or the like.

(b) Conventional technology For example, JP-A-61-110358 (G11B15.
・'467) Publication states that in a video tape recorder, etc., the envelope of the reproduced video signal is taken in, and the amount of delay (tracking data) of the reproduction control signal (or reference signal) of the capstan servo system is determined so that the envelope is maximized. An auto-trunking device is described for controlling.

(c) Problems to be Solved by the Invention Incidentally, in the case of self-recording/playback, the reproduced image quality is significantly better if the auto-tracking operation is not performed. This is due to the fact that the auto-tracking operation does not allow tracing in exactly the same way as when recording. Therefore, the auto-tracking device determines whether it is self-recording or not.
It is desirable to have a function that can determine whether or not to perform an auto-tracking operation.

(D) Means for Solving the Problems In the present invention, when the tracking data after the auto-tracking operation is within a predetermined range from the standard tracking data, it is determined that - self-recording/playback is being performed.

In addition, in order to make more accurate determinations, we investigated the variation in the envelope of the playback output and adopted the condition that the variation was large, or adopted FM recording with a rotating head (separate from the one for video) for the audio signal. ~'TR combines the condition that the auto-tracking result with only the video signal and the auto-tracking result with only the audio signal differ by a predetermined amount or more with the above-mentioned condition, and when multiple conditions are true, self-recording and playback is performed. I judge that.

(e) Function According to the present invention, it is possible to determine whether or not self-recording is being performed by using predetermined conditions such as tracking mail volume, so that there is an advantage that it can be easily identified.

(Example Embodiments of the present invention will be described below with reference to the drawings.

Generally, in a VTR, the CTL signal F30H2 is sent in the longitudinal direction of the tape during recording in order to use it for tracking control.
) are recorded. During reproduction, tracking servo is executed by comparing the phase of the reproduced CTL signal and the reference signal and controlling the tape running phase using lever t''L.

The delay amount of the reproduced CTL signal is adjusted to prevent noise from occurring on the reproduced screen during compatible reproduction. Therefore, this amount of delay is called trunking data.

In Figure 1, 1.2 is a video rotating head, 3.4
5 is an input terminal for an RF switching (RFSW) pulse for video head switching control, and 14 is an input terminal for an AF switching (AFSW) pulse for audio head switching control by delaying the RFSW pulse.
) This is a creation circuit that creates pulses. 6.7 is a preamplifier, 8.9 is an envelope detection circuit, 10 is a microcomputer for tracking control, 11 is a capstan servo circuit, 12 is a variable delay circuit, and 13 is an input terminal for a reproduced CTL signal.

The output of the video rotating radar 1.2 is converted into one system of signals by RFS~' and input to the detection circuit 8. The detection circuit 8 extracts the envelope of the reproduced output. Similarly, the output of the audio rotary head 3.4 is also A F S
W, the signal becomes one system of signals and is input to the detection circuit 9. The detection circuit 9 extracts the envelope of the audio reproduction output.

The microcomputer 10 uses the output of the detection circuit 8.9 as an A/D input. The microcomputer 10 has an A/D converter, converts the analog value supplied to the A/D input into a digital value, and captures the digital value at a predetermined timing. The microcomputer 10 also has an RF SW for timing control.
A mode signal is provided that controls the signal and timing for starting ATR autotracking.

First, as shown in Figure 83, the ATR used for fishing on a boat has a microcomputer 1.
When the PLAY mode signal is detected at 0, the ATR operation is started. Next, the rising edge of the RFSW signal is detected, and the output of the detection circuit 8 is A/D converted and inputted. This is repeated at predetermined sampling intervals. This sampling interval is, for example, 1 ms. This sampling is I
Executed between field frames (one frame period may be sufficient)
.

All sample values between one field interval are added (integrated) to obtain a value N corresponding to the current envelope. At this time, if the trunking adjustment has not been completed, control is performed to find the maximum value of this envelope.

Therefore, if it is not the maximum value here, the delay amount is changed by a predetermined amount. This is from the microcomputer 10 to the variable delay circuit 12.
be instructed. When the maximum value is determined, the adjustment operation ends. When the adjustment operation is completed, the standard tracking data S
It is checked whether there is tracking data N for the maximum value of the envelope within a predetermined range from (the center value of the delay amount of the reproduced CTL signal). When it is within the range, it is determined that it is a self-edge and the tracking data N is replaced with the standard tracking data S. When it is outside the range, it is determined that it is compatible playback and the trunking data N is used as is. The operation of ATR is thus completed.

Further, in the above embodiment, the ATR operation is performed once, but the ATR operation may be restarted when the maximum value is multiplied by 0.8 or 1.2 and the value falls below or exceeds that value. .

FIG. 4 is a diagram showing another embodiment. First, the microcomputer 10
The rising edge of the F SW signal is detected, and the output of the detection circuit 8 is A/D converted and input. This is repeated at predetermined sampling intervals. This sampling interval is, for example, 1 ms. This sampling is performed for one field period (one frame period may be sufficient). All sample values for one field period are stored in memory. And this one
The maximum (fiM and minimum 1i
Remove iI. Furthermore, the minimum value is subtracted from the maximum value M to calculate the difference Y (see FIG. 2).

Next, the predetermined value X and the output difference Y are compared, and when X<Y, it is determined that compatible reproduction is performed, and the value obtained in FIG. 3 is used as the tracking data. Also, when X≧Y, the third
The standard trunking data S and the tracking data N are compared in the same way as the judgment block B in the figure, and if they are within the range, it is determined that the tracking data is self-recorded and the tracking data is replaced with the standard tracking data S. Furthermore, when it is outside the range, even if the detected output is flat (that is, there is no output difference), it is determined that the reproduction is compatible and the value of N is used as is for the tracking/king data as described above.

FIG. 5 shows the embodiment of FIG. 3, and is a method of looking at the difference in tracking data with respect to the maximum value of the video detection output and the audio detection output.

Therefore, the part surrounded by the dotted line is the AT according to the video in Figure 3.
Since this is the same as the R operation, the explanation will be omitted. Therefore, as shown in FIG. 5, tracking data for the maximum value of the envelope is first obtained on the video side, and then tracking data for the maximum value of the envelope is obtained on the audio side in a similar manner. When the tracking data for the video side and the audio side are obtained, the tracking data are compared, and it is determined whether the comparison result (difference between the two) falls within a predetermined range. If it is not within the predetermined range, it is determined that compatible playback is being performed, and the value obtained in FIG. 3 is used as the tracking data. When it is within the predetermined range, the standard tracking/king data chain S and tracking data N are compared in the same way as in judgment block B in Figure 3, and when it is within the predetermined range, it is determined that it is a self-recorded record and standard trunking is performed. Replace with data value S. If it is outside the range, even if the difference in tracking data is within a predetermined range, it is determined that the playback is compatible (other recording), and the value of N is used as is for the tracking data as described above.

It is also conceivable to combine the embodiments shown in FIGS. 4 and 5. For example, a configuration that performs the determination shown in Figure 3 when either the envelope variation (Figure 4) or the creep in the audio and video auto trunking results (Figure 5) is true. is possible.

A large variation in the envelope and a large difference between the maximum and minimum values indicate a large variation.)
In this case, it is thought that this is because the trace trajectories of the track on the tape and the head are slightly different, and there is a high possibility that the playback is compatible. However, it is dangerous to make judgments based solely on envelope variations, so it is also necessary to check whether the tracking data is within a predetermined range of standard values.

The difference in auto-tracking results based on the audio and video playback signals (difference in tracking data) is due to the difference in the device used for recording and the device used for playback (the positional relationship between the video and audio heads is different). This is thought to indicate that. In this case as well, it is dangerous to make a decision on your own, so it is also checked whether the video (or audio) tracking data is within a predetermined range.

As mentioned above, basically the auto tracking operation is given priority, and when certain conditions are met, the auto tracking operation is canceled, the tracking data is set to the standard value, and the playback operation is continued. There is.

A method of determining self-recording/playback or compatible playback based on the shape of the envelope may also be considered. In other words, in the case of self-recording and playback, when the track/king status changes, the envelope is approximately flat and only the level changes, whereas in the case of compatible playback, the envelope changes due to the linearity of the track. The envelope shape changes because the level in the first half, second half, or middle of the signal decreases in particular.

That is, when the tracking state changes as shown in FIG. 7 (■ is the best state), the shape of the envelope changes as shown in FIG. 8, for example.

FIG. 9 shows a flowchart when this discrimination method is used. Auto tracking (AT
R) Operation is initiated. In the auto-tracking operation, first, the tracking value (the amount of delay given to the reproduction control signal) is set to the value (tracking center VL) for self-recording and reproduction. In this state, the envelope level for one frame is sampled at 1 m5ec intervals and summed (1 minute) to obtain a value indicating the envelope level.

At the start of ATR, in order to determine the shape of the envelope,
Of the 15 samplings for one field, the sum of the first and second sampling values representing the first half, the sum of the seventh and eighth sampling values representing the center, The sum of the 14th and 15th sampling values representing the second half is calculated and stored. These are the three numerical values representing the envelope shape at the start of ATR, and will be used later.

A comparison of envelope levels is then performed.

This is to find the point where the envelope is maximum, and compares the previous level and the level obtained this time. The operation is controlled based on this result.

After the level comparison is completed, conditional branching is performed depending on the comparison result and past actions. If the ATR operation has ended, the process proceeds to the next step, which is determination of self-recording/playback/compatible playback.

At the start of ATR, there is no value to compare, so next the tracking value is changed by a predetermined amount.

The direction in which the tracking value is changed is predetermined, and first, as shown in FIG. 8, it is changed in the direction of increasing the amount of delay (from ■ to ■). After the change, the playback envelope will be sampled again. This loop is then repeatedly executed until the ATR operation is completed.

Thereafter, the tracking value is changed as follows.

If the current level is greater compared to the previous envelope level, the direction of the change remains unchanged. When the current level becomes smaller than the previous level a predetermined number of times (for example, three times) in a row, the direction of change is changed to a direction that reduces the amount of delay, that is, it is determined that point ■ in Figure 8 has been reached. It's a no-fu-ke.

Even after reversing the change direction, if the current level is large, the change continues in the same direction. Then, at the point when the current level becomes smaller a predetermined number of times (for example, three times) in a row, that is, when it is determined that the point shown in Figure 8 (■) has been reached, at the tracking value a predetermined number of times (three times) earlier, Assume that the envelope is maximized. By setting this value, the ATR operation ends.

Data collection for determining the shape of the envelope is also performed at points ■ and ■ in FIG. In other words, the shape of the envelope is checked at three locations.

Next, a method for determining self-recording/playback/compatible playback will be explained.

First, it is determined whether the level D of the envelope at the end of the ATR operation is greater than a predetermined reference level Z. If it is small, it is immediately determined that compatible playback is being performed. If it is larger, proceed to the next condition. In the next step, envelope shape determination is performed.

The envelope shape is determined as shown in FIG.

At each check point, values representing the first half, middle, and second half levels are stored, and these values are used.

The level difference between the first half and the center is A, and the level difference between the second half and the center is B.
shall be. If the value of B is larger than the predetermined value X, the shape of A is 7.
It is determined that it is not Ranotto. For example, if it is down by 25% or more, it may be determined that it is not flat.

If it is determined that two or more of the three change points are not flat, it is determined that compatible playback is to be performed. On the other hand, if there are two or three flat points, proceed to the next step.

In the next step, self-edge 7/compatible playback is determined depending on how far apart the standard tracking value (delay amount in the case of self-recording/playback) and the tracking value after ATR are. In other words, if the tracking value after ATR is not within a predetermined range (±Y) centered on the standard tracking value (the difference between the tracking value after ATR and the standard tracking value is C<Y), compatible playback is not possible. to decide. If it is within the range, it is judged as self-recording. In the embodiment, this predetermined range is changed depending on the result of shape discrimination.

In other words, in this step, it is checked whether the difference C between the tracking center value and the tracking value after ATR is smaller than a predetermined value Y. , changed in 3 cases −
I'm here. If it becomes flat all three times, it is determined that the possibility of self-recording and reproducing is higher than the shape determination, so the value of Y is increased to widen the range in which self-recording and reproducing is determined.

Considering that there is a possibility of compatible playback if the flat state occurs only two out of three times, the accuracy of self-edge judgment is improved by narrowing the judgment of self-recording and making the conditions stricter. is being measured. When self-recording/playback/compatible playback is determined, a predetermined operation is executed depending on the result. For example, in the case of the embodiment shown in FIG. 9, when it is determined that self-recording/reproduction is performed by the operation in the flowchart, and the tracking value after ATR is within a predetermined range from the tracking center value, the tracking value is forcibly set to the tracking center. Do the action. Note that the predetermined range in this case is set narrower than the predetermined range in FIG. 9.

According to this embodiment, accurate discrimination is possible even in a VTR that does not have an FM audio function.

(G) Effects of the Invention As described above, according to the present invention, it is possible to easily determine whether self-recording/playback is being performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the embodiment, FIG. 2 is a waveform diagram showing an example of an envelope waveform, FIGS. 3, 4, and 5 are flow charts showing the operation of the embodiment, and FIG. 6 is an explanatory diagram of the operation of FIG. 5; FIG. 7, FIG. 8, and FIG. 10 are explanatory diagrams of other embodiments, and FIG. 9 is a flowchart. 1.2...Video head, 3.4...Audio head, 8.9...Envelope' detection, 10...Microcomputer, 12...Variable delay means.

Claims (2)

[Claims] (1) If the best tracking data obtained by an auto-tracking device that obtains the best value of tracking data based on the playback output is within a predetermined range from standard tracking data, it is determined that it is self-recording. Re-judgment device. (2) Conditions and patents in which the magnitude of variation in the playback envelope within a predetermined period is less than or equal to a predetermined value, and/or the difference between the best tracking data based on video output and the best tracking data based on audio output is smaller than a predetermined value. A self-recording/reproduction determination device that determines self-recording/reproduction when both of the conditions recited in claim 1 are satisfied.