JPH06150639A - Detecting device for information of control signal - Google Patents

Abstract

PURPOSE:To accurately detect various kind of information such as frame infor mation from a control signal recorded in a unit of a field. CONSTITUTION:The cumulative number of pulses of a capstan FGA and a capstan FGB at a rising edge and a falling edge of a control signal is counted by a free running counter 2. Next, the number of pulses of one field in a 'high' period are calculated and duty ratio of the control signal is calculated by a duty ratio calculating circuit 4. A signal in which duty ratio is different from the other is, for example, a control signal at the front of four fields sequence, specific field information SB is outputted. Also, a reproducing control signal CTL is frequency-divided into one half by a 1/2 frequency-dividing circuit 7. Thereby, frame information is detected. Even when a phase of frame information is different, since it is converted to a normal phase by specific field information, accurate frame information can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control signal information detecting device suitable for application to digital information editing devices.

[0002]

2. Description of the Related Art In a conventional VTR, as shown in FIG. 10, a control signal C is placed below, for example, a magnetic tape T.
It is usual that the TL is recorded every other track T1 of the video signal, that is, every other field (frame unit). As a result, the video signal reproduced from the magnetic tape T can be edited frame by frame, and the continuity of the signal after editing can be maintained.

[0003]

By the way, recently, many devices such as digital VTRs and PCM recordings record digitally video signals and audio signals. A signal recorded digitally in this way can be recorded in, for example, NTSC
When editing in synchronism with the TV signal of the system, it is necessary to record in units of 5 fields due to the sampling frequency and the like.

However, when the control signal is recorded in frame units as in the conventional case, there is a problem that editing cannot be performed because it cannot be distinguished in 5 field units. In this case, if the reproduced control signal is interpolated and converted into field information, editing can be performed in units of 5 fields, but this requires a circuit for interpolation, which makes the editing apparatus expensive and large. There is a problem that it becomes.

Further, as shown in FIG. 11, it is relatively easy to record the control signal in the field unit. Therefore, if this is recorded in the field unit, since there is no frame information, it can be edited by the conventional editing apparatus. Can not. In this case, it is possible to edit the reproduced control signal in units of fields by halving it to obtain frame information, but this cannot distinguish between odd frames and even frames. When editing is performed using this frame information, the seams of signals may become discontinuous.

Further, in the conventional VTR, since the control signal CTL does not include information such as color framing, after the video signal is reproduced, the color framing information included in the video signal is detected and phase adjustment such as color framing is performed. Was being done. Therefore, there are problems that it takes a long time for color framing and the color framing circuit becomes complicated.

[0007] For example, in a conventional editing VTR, color framing information in a video signal is detected after phase locking by the capstan phase servo, phase adjustment is performed based on this color framing information, and then the capstan phase servo is performed again. Was being done. For this reason, in the case of editing with color framing, the run-up section takes an extra 2 seconds or more as compared with the case of editing without color framing.

Further, in the conventional digital VTR, the color framing information is detected by demodulating the digital signal, but the circuit for detecting the color framing information from the video signal is complicated and expensive, and therefore the color framing information detection circuit. There is a demand to omit But,
Conventionally, there is no substitute for this, and the reality is that an expensive color framing detection circuit must be mounted.

Therefore, the present invention has been made to solve the above-mentioned problems, and it is possible to accurately detect various information such as frame information and color framing information from a control signal recorded in field units. The present invention proposes an information detection device for various control signals.

[0010]

In order to solve the above-mentioned problems, in the first invention, a control signal is provided for each field, and the duty ratio of the control signal in a specific field is set to a control signal in another field. A control signal information detecting device for detecting various information from the control signal when a control signal different from the duty ratio of the control signal is inputted, and a duty ratio detecting means for detecting the duty ratio of the control signal, By comparing the ratio and the reference value, the specific field discriminating means for discriminating whether or not the control signal is the control signal in the specific field, and dividing the control signal,
It is characterized by further comprising frequency dividing means for resetting the frequency dividing operation by the output of the specific field discrimination means.

In the second aspect of the invention, the control signal is recorded on a field-by-field basis, and the control signal is reproduced such that the duty ratio of the control signal in a specific field is different from the duty ratios of the other control signals. Is a control signal information detecting device for detecting various information from the control signal, the duty ratio detecting means for detecting the duty ratio of the control signal is compared with the reference value. A specific field discriminating means for discriminating whether or not the control signal is a control signal in a specific field, and a field number adding means for sequentially adding a number to subsequent control signals based on the control signal in the specific field,
The control signal is frequency-divided, and frequency division means for resetting the frequency division operation by the output of the specific field discrimination means is provided.

In the third aspect of the invention, when the control signal is provided for each field and the control signal duty ratio of the control signal in a specific field is different from the duty ratio of the control signal in another field, the control signal is input. A control signal information detecting device for detecting various kinds of information from the control signal, wherein the control signal is identified by comparing the duty ratio with a reference value with a duty ratio detecting means for detecting the duty ratio of the control signal. Specific field discriminating means for discriminating whether or not it is a control signal in the field, field number adding means for sequentially adding a number to the control signal subsequent to the control signal in the specific field, and the control signal. The frequency division means for resetting the frequency division operation by the output of the specific field discrimination means as well as the frequency of the reference field signal added in accordance with the color framing by the same reference number as the field number added by the field number addition means. The generating means, the number comparing means for comparing the field number and the reference number, and the capstan motor speed control means for controlling the rotation speed of the capstan motor based on the comparison result of the number comparing means are provided. The color framing is matched by controlling the rotation speed of the capstan motor until they match.

[0013]

In the first invention of FIG. 1, the two FGs built in the capstan motor of the VTR (not shown).
(Frequecy Generator) to Capstan FGA, FG
B is supplied to the free running counter 1, and the cumulative pulse number counted here is supplied to the latch circuit 3. In the latch circuit 3, the cumulative pulse number is latched at the rising and falling timings of the control signal CTL, and in the duty ratio calculating circuit 4, the cumulative pulse number is latched at the rising edge immediately before the cumulative pulse number latched at the falling edge. By subtracting the number, the number of pulses in the high period of the control signal CTL is calculated.

The duty ratio of the control signal CTL is calculated by comparing this frequency with the number of pulses in one field. Next, the specific field discriminating circuit 6 compares the duty ratio with the reference value to discriminate the specific field, and the specific field information SB (FIG. 2D) is output.

Also, in the control signal information detection circuit, the reproduction control signal CTL divides the reproduction control signal CTL by ½.
Is divided by (Fig. 2 (C1, C2)). When the reproduction is started from the second and fourth control signals CTL (FIG. 2 (B1)), the frame information SC (FIG. 2 (E1)) output from the falling edge detection circuit 8 is accurate for each frame. Since it is output, it is directly output to the outside through the counter 9. The value of the counter 9 accurately represents the number of frames after the start of reproduction.

On the other hand, when the reproduction is started from the third control signal (FIG. 2 (B2)), the frame pulse SC output before the first reset pulse b (FIG. 2 (D)) is Since it is output for each field in the middle of the frame ((E2) in FIG. 2), it is discarded without being output to the outside, and the frame pulse SC after the first reset pulse b is output. However, since the discarded frame pulse SC accurately represents the number of frames from the start of reproduction, the number of frames counted by the counter 9 is output as it is.

Further, in the second invention of FIG. 6, the control signal CTL of 4 field sequence and the control signal CTL of 5 field sequence are recorded on the same track (FIG. 5).
Is reproduced and input, the control signal CTL at the beginning of the 5-field sequence is detected by the audio specific field discrimination circuit 10, and with this as a reference, all the control signals CTL are added with “0” by the audio field number addition circuit 12. Numbers are sequentially added up to "4".

The control signal at the beginning of the 4-field sequence is detected by the video specific field discrimination circuit 11, and with this as a reference, the control signal CTL is sequentially numbered from "0" to "3" by the video field number addition circuit 12. Is added.

In the third invention of FIG. 7, the reproduction field number M of the video field information SE (FIG. 8 (B1) to (B3)) outputted from the video field number adding circuit 13 and the reference field signal generating circuit 15 are provided. The reference field number N of the reference field signal SF output from is compared by the field number comparison circuit 14. The difference between the field numbers N and M calculated here (NM)
Thus, a control signal SG for controlling the speed of the capstan motor as shown in FIG. 9 is output. In response to this, the capstan motor speed control circuit 16 outputs a speed control signal SH, which controls the rotational speed of the capstan motor.

Then, when the difference (NM) becomes "0", that is, when the color framing is matched, the changeover switch 17 is changed over to the terminal b side, and thereafter the normal capstan phase servo is performed. .

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a control signal information detecting device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a system of a control signal information detecting apparatus according to the first invention. This control signal information detection device is applied to, for example, an editing device,
Here, a case of editing video information and the like input from a VTR (not shown) will be described.

Control signal CT reproduced by VTR
It is assumed that L is recorded on the magnetic tape T in units of fields (FIG. 11). In this example, in order to simplify the explanation, as shown in FIG.
A case where this is repeatedly recorded as a block will be described. In the figure, the numbers (0) to (3) added to the respective control signals CTL indicate field numbers.

In such control signal CTL, the control signal CTL continuously reproduced.
The control signal CTL at the head of each block so that (0) to (3) can be divided for each block
The duty ratio of (0), that is, the ratio of the period of being “high” in one field is changed from the duty ratio in the other fields.

In this example, the duty ratio of the first field is 60%, and the duty ratio of the other fields is 50%. This is the duty ratio when the capstan motor (not shown) of the VTR is rotating forward,
When the capstan motor rotates in the reverse direction, the duty ratio of the leading field becomes 40%.

Referring to FIG. 1, the forward / reverse rotation detecting circuit 1 has two Fs built in the capstan motor of the VTR.
Signals sent from G (Frequecy Generator), here capstans FGA and FGB, are input. The two FGs of the VTR are mounted at appropriate intervals. As shown in FIG. 3A, when the capstan FGA sent out during forward / reverse rotation is used as a reference, the capstan FGB sent out during forward rotation is Capstan FG as shown in FIG.
It is delayed from A by 0.5 pulse. Further, the capstan FGB sent at the time of reverse rotation is 0.5 pulse earlier than the capstan FGA as shown in FIG.

Since the relationship between the capstan FGA and the capstan FGB changes between the forward rotation and the reverse rotation, the forward / reverse rotation detection circuit 1 (FIG. 1) detects the rotation direction of the capstan. Thus, the moving direction of the magnetic tape T, that is, the reproducing direction of the control signal CTL can be known.
The forward / reverse rotation information is supplied to the duty ratio calculation timing generation circuit 5, the specific field determination circuit 6, and the 1/2 frequency division circuit 7.

On the other hand, the capstans FGA and FGB are also supplied to the free running counter 2, where the cumulative number of pulses from the start of reproduction is counted. This count value is supplied to the latch circuit 3, where it is latched at the timing of the reproduction control signal CTL. In this example, as shown in FIG. 4, the reproduction control signal CTL is latched at the rising and falling timings of the capstan both in the normal rotation and in the reverse rotation.

That is, in the latch circuit 3, when the reproduction control signal CTL becomes "high", and "low".
The cumulative pulse number of the capstans FGA and FGB at the time of is detected. This count value is supplied to the duty ratio calculation circuit 4.

The reproduction control signal CTL is also supplied to the duty ratio calculation timing generation circuit 5. In the duty ratio calculation timing generation circuit 5, the duty ratio calculation instruction signal SA is sent at the rising or falling timing of the reproduction control signal CTL based on the forward / reverse rotation information. In this example, as shown in FIG. 4, the duty ratio calculation instruction signal SA is sent at the falling timing of the control signal CTL during the forward rotation, and is sent at the rising timing during the reverse rotation.

The duty ratio calculation instruction signal SA is supplied to the duty ratio calculation circuit 4. Then, the reproduction control signal C is generated at the timing of the duty ratio calculation instruction signal SA.
Capstan FGA during the "high" TL,
The FGB frequency is calculated. For example, when the capstan motor rotates forward, the cumulative number of pulses of the control signal CTL input in synchronization with the duty ratio calculation instruction signal SA,
That is, the number of pulses in the “high” period is calculated by subtracting the number of accumulated pulses at the rising edge immediately before that from the number of accumulated pulses at the falling edge of the control signal CTL.

In the duty ratio calculation circuit 4, the number of pulses in the “high” period of the control signal and the number of pulses in one field period, that is, in the “high” period and the “low” period, are next described. "High" in one field by comparing with the sum of numbers
The duty ratio of the period is calculated. In this example, the duty ratio of 60% and the duty ratio of 50% are calculated as described above. 40% when the capstan motor reverses
And a duty ratio of 50% are calculated.

The duty ratio calculated here is supplied to the specific field discrimination circuit 6, where it is compared with a reference value. In this example, the reference value is set to 55% during normal rotation, and if it exceeds this value, it is determined to be the first field in one block, and if it is less than this, it is determined to be the second to fourth fields. The reference value is 4 when reversing.
It is set to 5%, and if it is less than this, it is determined to be the first field, and if it exceeds this, it is determined to be the second to fourth fields.

When it is determined that the field is the first field, the specific field information SB is output. By using this specific field information SB, the editing work can be performed accurately and various controls can be performed.

Further, this control signal information detecting device can accurately detect frame information as described below.

That is, the reproduction control signal CTL input in FIG. 1 and the normal / reverse rotation information output from the normal / reverse rotation detection circuit 1 are also input to the 1/2 frequency dividing circuit 7. Now, for example, as shown in FIG. 2B1, the control signal CTL in the second field of one block is
It is assumed that the reproduction is started from (1). At this time, as shown in (C1), the second control signal CTL first input by the 1/2 divider circuit 7 which has been reset by the reset pulse a supplied from the outside.
Since the frequency division is started from (1), the frequency division signal becomes "high" in the second and fourth fields and becomes "low" in the first and third fields.

On the other hand, when the specific field discriminating circuit 6 detects the leading control signal CTL (0), the specific field information SB (reset pulse b) is output as shown in FIG. / 2 frequency divider 7
Is supplied to. Then, the 1/2 divider circuit 7 is reset at the timing of the reset pulse b.

However, in this case, when the reset pulse b is input to the 1/2 frequency dividing circuit 7, the 1/2 frequency dividing signal is "low", so that resetting is not performed and the frequency dividing processing is performed as it is. Continued. This 1/2 frequency-divided signal is supplied to the falling edge detection circuit 8, and when a falling edge is detected here, frame information (frame pulse) SC is output as shown in (E1) of the same figure. This frame pulse SC
Is output to the outside through the counter 9 (FIG. 1). Since the counter 9 accurately counts the number of frames after the start of reproduction, by using this, editing can be performed accurately.

As described above, when the reproduction is started from the second control signal CTL (1), the phase of the frame pulse SC immediately after the reproduction is started is normal, that is, the frame pulse SC is generated at each recorded frame delimiter. Is output. This is the fourth control signal CTL
The same applies when reproduction is started from (3).

On the other hand, when the reproduction is started from the third control signal CTL (2) as shown in (B2) of the same figure, the 1/2 divider circuit as shown in (C2) of the same figure. At 7, the frequency division is started from the third control signal CTL (2). Therefore, the 1/2 frequency-divided signal has "high" in the third field and "low" in the fourth field.

Then, when the control signal CTL (0) at the beginning of the next block is input, the 1/2 frequency division signal becomes "high". Then, this control signal CT at the beginning
The reset pulse b shown in FIG. 6D is input at the falling timing of L (0), and the 1/2 frequency dividing circuit 7 is reset at this timing, and the 1/2 frequency dividing signal becomes "low". Then, the frequency division is performed again from the time when the next control signal CTL (1) is input.

The 1/2 frequency-divided signal is supplied to the falling edge detection circuit 8, and the frame pulse SC is output at the falling edge timing as shown in FIG. In this case, the frame pulse SC immediately before the start of reproduction, which is transmitted before the 1/2 frequency division is reset by the reset pulse b, is shifted by one field from the normal frame pulse. That is, the frame pulse SC is output at the end position of the first field in one frame.

Therefore, this frame pulse SC is discarded as an error and is not output to the outside. The frame pulse S generated after the first reset pulse b
Since C is in a normal state, it is directly output to the outside. However, since the discarded frame pulse SC accurately represents the number of frames reproduced so far,
The counter 9 directly counts the number of frame pulses SC supplied immediately after the start of reproduction.

In the above description, the information is detected from the control signal CTL that includes only the information regarding the video signal. However, as described below, the information regarding both the video signal and the audio signal is included. It is also possible to detect the information separately from the existing control signal CTL.

In this case, for example, as shown in FIG. 5A, the information regarding the video signal is recorded in the 4-field sequence, and the information regarding the audio signal is recorded in the same track in the 5-field sequence. In this example, the duty ratio of the control signal CTL at the beginning of the 4-field sequence is set to 60%, and the duty ratio of the control signal CTL at the beginning of the 5-field sequence is 40%.
It is set to%. The duty ratio of the other control signals is 50%. When the duty ratio of 40% and the duty ratio of 60% overlap, the duty ratio of 60% is set.

Now, assuming that the reproduction is started from the third control signal CTL of the four-field sequence as shown in FIG. 7B, the same processing as that described above results in a half as shown in FIG. The divided signal is output. In this case, when the 1/2 frequency-divided signal is "high", the same figure (D)
The reset pulse b is input to reset the frequency division. Then, the frame pulse SC of FIG. 6E is output at the falling timing of the 1/2 frequency-divided signal. This frame pulse SC can represent the timing of color framing of the image, for example.

Here, when a control signal CTL having a duty ratio of 40% is further detected, FIG.
The audio pulse SD as shown in is output. The audio pulse SD can represent the timing of audio framing, for example. By using this audio pulse SD, it becomes possible to edit audio information accurately.

When the capstan motor rotates in the reverse direction, 4
The 0% duty ratio is the head control signal CTL of the 4-field sequence, and the 60% duty ratio is the head control signal C of the 5-field sequence.
It is determined to be TL.

FIG. 6 shows a system of a control signal information detecting apparatus according to the second invention. Here, the same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof is omitted. This control signal information detecting device is suitable for detecting information from the control signal CTL including information on audio and video as shown in FIG. 5 (A).

In FIG. 6, the duty ratio of the control signal CTL calculated by the duty ratio calculation circuit 4 is supplied to the audio specific field discrimination circuit 10 and the video specific field discrimination circuit 11. In the audio specific field discrimination circuit 10, the reference value is set to 45%, and this reference value is compared with the input duty ratio. Then, when the duty ratio is equal to or less than the reference value,
This is judged as the control signal CTL at the beginning of the audio sequence, that is, the 5-field sequence, and
The audio pulse SD as shown in (F) is output.

The audio pulse SD is supplied to the audio field number addition circuit 12. The reproduction control signal CTL is also supplied here, and the control signal CTL when the audio pulse SD is input is given a number 0, for example, as the head control signal CTL. 1 for the subsequent control signal CTL
The numbers from 4 to 4 are output in order.
This makes it possible to accurately edit the audio information and maintain the continuity of signal joints.

Further, the video specific field discrimination circuit 11
, The reference value is set to 55%, and the control signal CTL having a duty ratio higher than this is determined to be the head control signal CTL of the video sequence, that is, the 4-field sequence. Then, the specific field information SB (reset pulse b) shown in FIG. 5D is transmitted. This reset pulse b is 1/2 as in the above.
It is supplied to the frequency dividing circuit 7 and also to the video field number adding circuit 13.

The reproduction control signal CTL is also input to the video field number addition circuit 13, and the control signal CTL when the reset pulse b is input is
For example, "0" is added as the reproduction field number M. And, in the control signal CTL after this,
The playback field numbers from "1" to "3" are sequentially added and the video field information is output. By using this video field information, the video signal can be edited accurately and the continuity of the signal connection can be maintained.

FIG. 7 shows a system of a control signal information detecting device according to the third invention. The same parts as those in FIG. 6 are designated by the same reference numerals and detailed description thereof is omitted.

The information detecting device for the control signal is
It can be used as a detection circuit for color framing information. In FIG. 7, the video field information SE output from the video field number adding circuit 13 is
As shown in FIG. 8B1, a field having a duty ratio of 60% is given a reproduction field number M of “0”, and subsequent fields are given reproduction field numbers M of “1” to “3” in order. ing.

The video field information SE is supplied to the field number comparison circuit 14. The field number comparison circuit 14 includes the reference field generation circuit 15 as shown in FIG.
The reference field signal SF as shown in (A) is also supplied. The reference field signal SF is generated at the same timing as the synchronizing signal of the video signal. For example, in the case of the VTR, it is generated by the recording digital processor.
It is also possible to use this.

In the reference field signal SF, the first field and the third field are "high", and the second field and the fourth field.
The field is "low". Then, the reference field number N from "0" to "3" is sequentially added in units of fields required for color framing, in this example, in units of 4 fields.

In the field number comparison circuit 14, the reproduction field number M is subtracted from the reference field number N. The video field information SE of FIG. 8 (B1) is the case where the color framing is matched, and as shown in FIG. 9, all the differences (NM) between the reference field number N and the reproduction field number M are "0". become.

On the other hand, video field information SE when color framing is delayed by one field
8B, the reproduction field number M is delayed by one field with respect to the reference field number N, as shown in FIG. 8B2. Therefore, the difference (NM) between the field numbers N and M is "-3" or "+1". The case where the color framing is advanced by 3 fields is the same as the case where the color framing is delayed by 1 field. Similarly, the video field information SE when the color framing is advanced by one field is as shown in FIG. 8 (B3), and the difference (NM) is "-1" or "+3".

In this way, the difference (NM) between the reference field number N and the reproduction field number M changes depending on the color framing state, and it is possible to judge the color framing state. Then, the signal SG indicating the color framing state is output from the field number comparison circuit 14.

In this example, when the difference (NM) between the field numbers N and M is "-3", "+1" and "+2" as shown in FIG. 9, the color framing is delayed. Is output to the capstan motor speed control circuit 16. Then, the capstan motor speed control 16 outputs a control signal SH for increasing the rotational speed of the capstan motor by, for example, 1.5 times, and the control signal SH is supplied to the capstan motor via the changeover switch 17.

As a result, the rotation speed of the capstan motor is increased by 1.5 times, and the reproduction control signal CT to be inputted is inputted.
The timing of L becomes faster. Therefore, the timing of the video field information SE output from the video field number adding circuit 13 is accelerated, so that the difference (NM) between the field numbers N and M changes. The speed control of the capstan motor is performed until the difference (NM) becomes "0", that is, until the color framing is matched.

Similarly, when the difference (NM) between the field numbers N and M is "-2", "-1" and "+3",
A signal SG indicating that the color framing is in progress is output, which causes the capstan motor speed control circuit 16 to output a control signal SH for increasing the rotation speed of the capstan motor by, for example, 0.5 times. This increases the rotational speed of the capstan motor by 0.5 times.

Since the reproduction timing of the reproduction control signal CTL is delayed and the output timing of the video field information SE is delayed, the difference (NM) between the reference field number N and the reproduction field number M is changed. Become. Also in this case, until the difference (NM) becomes "0",
That is, the speed control of the capstan motor is performed until the color framing matches.

When the difference (NM) between the field numbers N and M becomes "0", the changeover switch 17 is changed over to the terminal b side. Thus, for example, the control signal of the capstan phase servo circuit of the VTR is supplied to the capstan motor via the changeover switch 17, and the normal capstan phase servo is performed.

When the control signal information detecting device is applied to the editing device, the phase lock occurs when the difference (NM) between the field numbers N and M becomes "0", so that the video is immediately recorded. It becomes possible to edit the signal.
Contrary to the above description, it is also possible to perform capstan phase servo and lock the phase before performing color framing.

In the above embodiment, the NTSC system 4 is used.
The case of detecting various kinds of information from the control signal CTL of the field sequence has been described. However, in the control signal information detecting device of the present invention, the PAL system and the S
Various kinds of information can be detected from the control signal CTL of 8 field sequence such as ECAM system.

[0068]

As described above, according to the first aspect of the invention, when the control signal is provided for each field and the control signal whose duty ratio in a specific field is different from the duty ratio of another field is input, A specific field is detected by detecting the duty ratio, and various information such as frame information can be detected based on this.

Therefore, according to the first aspect of the invention, the frame information can be accurately detected from the control signal recorded in the field unit, so that the normal editing performed in the frame unit becomes possible. Further, since it is possible to edit in field units, it is possible to perform editing in field units as in the case of editing by synchronizing audio information recorded by PCM with a television signal. Further, it is possible to accurately count the number of frames regardless of which control signal is reproduced at the start of reproduction, and thus it is possible to perform editing accurately.

The second invention is such that a field number is added to the control signal with reference to a specific field having a different duty ratio. Therefore, the second
According to the invention, even when different timing information such as color framing and audio framing is included in the control signal, it is possible to distinguish and detect such information.

The third aspect of the present invention determines the color framing state of the reproduction control signal by comparing the reproduction field number added to the control signal with the reference field number of the reference field signal generated according to the color framing. By this, the rotation speed of the capstan motor is controlled to match the color framing.

Therefore, according to the third invention, the color framing can be performed in a shorter time than the conventional case where the color framing is performed after the phase lock is applied by the capstan phase servo. It is possible to shorten the run-up section when editing. Further, since color framing can be performed only by comparing the numbers, the circuit configuration is simple and the cost is low.

[Brief description of drawings]

FIG. 1 is a system diagram of a control signal information detection device according to a first invention.

FIG. 2 is a waveform diagram of each signal when information is detected from a video control signal.

FIG. 3 is a diagram illustrating a relationship between capstans FGA and FGB of a signal transmitted from two FGs incorporated in a capstan motor.

FIG. 4 is a diagram illustrating operation timings of a latch circuit 3 and a duty ratio calculation timing generation circuit 5.

FIG. 5 is a waveform diagram of each signal when information is detected from a video and audio control signal.

FIG. 6 is a system diagram of a control signal information detection device according to a second invention.

FIG. 7 is a system diagram of a control signal information detection device according to a third invention.

FIG. 8 is a waveform diagram of each signal when detecting color framing information.

FIG. 9 is a diagram illustrating a color framing state and a speed control method for a capstan motor.

FIG. 10 is a diagram illustrating a control signal recorded in frame units.

FIG. 11 is a diagram illustrating control signals recorded in field units.

[Explanation of symbols]

 1 Forward / Reverse Detection Circuit 2 Free Running Counter 3 Latch Circuit 4 Duty Ratio Calculation Circuit 5 Duty Ratio Calculation Timing Generation Circuit 6 Specific Field Discrimination Circuit 7 1/2 Dividing Circuit 8 Fall Detection Circuit 9 Counter 10 Audio Specific Field Ratio Discrimination Circuit 11 video specific field ratio discrimination circuit 12 audio field number addition circuit 13 video field number addition circuit 14 field number comparison circuit 15 reference field signal generation circuit 16 capstan motor speed control circuit 17 changeover switch

Claims (6)

[Claims] 1. A control signal is provided for each field, and when a control signal whose duty ratio of the control signal in a specific field is different from that of the control signal in another field is input, A control signal information detecting device for detecting various information from a control signal, wherein the duty ratio detecting means for detecting the duty ratio of the control signal is compared with the duty ratio and a reference value, and the control signal is A specific field discriminating means for discriminating whether or not the control signal is in the specific field; and a frequency dividing means for dividing the control signal and resetting the frequency dividing operation by the output of the specific field discriminating means. Contro featuring Information detection means for signal signals. 2. A control signal is recorded on a field-by-field basis, and the control signal recorded in such a manner that the duty ratio of the control signal in a specific field is different from the duty ratios of other control signals is reproduced and input. At this time, in a control signal information detecting device for detecting various information from the control signal, the duty ratio detecting means for detecting the duty ratio of the control signal and the duty ratio and a reference value are compared, A specific field discriminating means for discriminating whether or not the control signal is a control signal in the specific field, and a field number adding means for sequentially adding numbers to control signals subsequent to the control signal in the specific field. , The above With dividing the roll signal, control signal information detection means, characterized in that a dividing means for resetting the frequency division operation at the output of the specific field discriminating means. 3. A control signal is provided for each field, and when a control signal whose duty ratio of the control signal in a specific field is different from the duty ratio of the control signal in another field is input, A control signal information detecting device for detecting various information from a control signal, wherein the duty ratio detecting means for detecting the duty ratio of the control signal is compared with the duty ratio and a reference value, and the control signal is A specific field discriminating means for discriminating whether or not it is a control signal in the specific field, a field number adding means for sequentially adding numbers to control signals subsequent to the control signal in the specific field, Frequency dividing means for dividing the troll signal and resetting the dividing operation by the output of the specific field determining means, and the same reference number as the field number added by the field number adding means are added according to the color framing. Generating means for generating the reference field signal, number comparing means for comparing the field number with the reference number, and capstan motor speed control means for controlling the rotation speed of the capstan motor based on the comparison result of the number comparing means. The control signal information detecting means is characterized in that color framing is adjusted by controlling the rotational speed of the capstan motor until the field number and the reference number match. 4. The control signal information detecting apparatus according to claim 2, wherein the specific field discriminating means discriminates a control signal for audio information. 5. A control signal information detecting apparatus according to claim 2, wherein said specific field discriminating means discriminates a control signal for video information. 6. A changeover switch for changing over the output of the capstan motor speed control means and the output of the capstan phase servo means, and after the color framing is performed, the changeover switch is operated by the capstan phase servo. 4. The control signal information detection device according to claim 3, wherein the control signal is switched to the means side.