JP2554040B2 - Video playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a video reproducing apparatus, and is particularly suitable for application to a home video tape recorder (VTR).

[Background technology and its problems]

In the case of reproducing a tape recorded for a long time of about 2 to 3 hours in a home-use VTR, when the operator wants to find the image that the operator wants to see as quickly as possible, the so-called picture search is conventionally used. It was devised to operate the VTR in the so-called special playback mode. In the first picture search mode, the tape is fast forwarded or rewound in a state where the VTR is once set to the reproduction mode, so that the reproduction speed is higher than the reproduction speed (for example, about the reproduction speed).
(15 times) to get the reproduced image while running the tape. Thus, you can search for the image you want to see during playback. On the other hand, in the second special reproduction mode, the image is reproduced at a desired timing after once being set to the fast-forwarding or rewinding mode. In this way, the image currently sent during the fast-forwarding or rewinding is reproduced. You can check what it is while running the tape at high speed, thus searching for the painting material you want to see.

By the way, according to such a conventional special reproduction method, the recorded image is reproduced by trial and error, and how much further fast-forward or rewind is performed in relation to the image that the operator wants to see. It is only possible to get a good idea of whether it is good or not, and thus it is necessary to repeat the special reproduction operation until the image finally desired by the operator can be reproduced. For example, when a large number of programs are recorded on one tape, when searching for the head of one of the programs, there is a problem that a considerably complicated operation must be repeated.

[Object of the Invention]

The present invention has been made in consideration of the above points, and by allowing the head images of each program to be sequentially confirmed in the shortest possible time, the operator wants to see by a much simpler operation. The present invention is intended to propose a video reproducing device that makes it possible to easily search for an image.

[Outline of Invention]

In order to achieve such an object, in the present invention, the program identification signal recorded at the head of each program recorded on the tape is detected while the tape is running at a high speed, and the tape is predetermined every time the detection signal is obtained. The recording signal of the corresponding program is reproduced by switching to a state of running at a low speed for a time, and the running speed of the tape is returned to a high speed after the predetermined time has elapsed, and thus the tape is run at a high speed. As a result, the search speed of the recorded information to be searched can be increased, and the recorded information at the head of each program can be surely confirmed.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings. First
The figure shows a VTR as a whole, and an operator selects and operates one of the operation switch groups 1 to give a mode command signal to the system control circuit 2 from the operation switch. At this time, the system control circuit 2 The tape drive device 3 is drive-controlled to run the tape in the direction and speed corresponding to the commanded mode, and the signal processing circuit 4 is driven to record or reproduce a video signal or an audio signal on the tape, which is necessary. In response, the image is displayed and the sound is generated.

The operation switch group 1 has a recording (REC) switch 11 and a playback (PB) switch 12, and when these switches 11 and 12 are operated, the system control circuit 2 causes the tape drive 3 to operate the tape at a normal speed. While running, the signal processing circuit 4 records or reproduces a signal on or from the tape.

When the fast forward (FF) switch 13 and the rewind (REW) switch 14 are operated, the system control circuit 2 causes the tape drive device 3 to move the tape to a normal speed, for example.
It is run at a speed of 30 times in the forward direction or the reverse direction, and the signal processing circuit 4 does not record or reproduce the signal on the tape.

Further, when the medium speed feed / reproduction (CUE) switch 15 and the medium speed rewind / reproduction (REV) switch 16 are operated, the system control circuit 2 causes the tape drive device 3 to move the tape forward at a speed, for example, 10 times the normal speed. The video signal is reproduced by the signal processing circuit 4 and is displayed (in this case, the audio signal is not reproduced).

In addition to the above configuration, the operation switch group 1 further has a cue reproducing (INS) switch 17 and an index (IND) recording switch 18. The index recording switch 18 is used to sequentially record a large number of programs FE1, FE2, FE3 ... To the video signal track TR of the tape by operating the recording switch 11 as shown in FIG. 2 (A). By being operated at the timing corresponding to the beginning of each program, the control pulse signal CTL recorded on the tape in synchronization with each field of the programs FE1, FE2, FE3 ... The index signals IND1, IND2, IND3 ... Can be recorded via the system control circuit 2 and the signal processing circuit 4.

Here, the control pulse signal CTL is composed of a signal whose logic level is switched at a duty ratio of 1/2 with the recording time of a video signal of one frame as one cycle, while the index signal IND1, IND2, IND3 ... Have a duty ratio such that the ratio between the logical "H" section and the logical "L" section of the control pulse signal CTL is, for example, 20:80. It is possible to detect that an index signal is generated when the duty ratio of the control pulse signal obtained by reproducing at a fixed head changes from 50%.

On the other hand, the cue playback switch 17 commands the system control circuit 2 to perform the "cue playback mode".
At this time, the system control circuit 2 generates a predetermined time when the index signals IND1, IND2, IND3, ... Are generated while the VTR is fast-forwarding the tape in the fast-forward (FF) mode as shown in FIG. 2 (B). During T, it operates so that the VTR is once switched to the playback (PB) mode.

In order to realize such a mode, the system control circuit 2 has a configuration that operates according to the procedure shown in FIG. That is, at the initial start, the system control circuit 2 judges whether the cue play (INS) switch 17 has been pressed in step SP1 in the cue play (INS) mode, and if a negative result is obtained, it moves to step SP2 and waits. Enter the receiving mode. Eventually, when the cueing reproduction switch 17 is pressed and a positive result is obtained at step SP1, the system control circuit 2 makes a step.
After moving to SP3, the cue reproducing indicator lamp 21 (Fig. 1) is turned on to notify the operator that the cue reproducing mode has been entered, and then the procedure proceeds to step SP4. This step SP4 is a fast-forward switch
In the step of judging whether 13 (Fig. 1) has been pressed,
If a negative result is obtained, the process returns to step SP3 and step SP4
Repeat the judgment of. When a positive result is obtained in step SP4, the system control circuit 2 proceeds to the next step SP5, resets the index counter 22 (Fig. 1) to set the count content to "0", and then proceeds to step SP6. The index counter 22 is turned on to display the number "0", thereby notifying the operator that he / she has not yet entered the program search.

Then, the system control circuit 2 moves to step SP7 and sends a drive signal according to the fast-forward mode to the tape drive device 3 and the signal processing circuit 4 (FIG. 1) to run the tape at a high speed and to transmit the video and audio. Mute. Subsequently, the system control circuit 2 shifts to step SP8 and operates the index counter 22 to count "+1" to change the displayed content to the numerical value "1", which causes the operator to select the first program FE1 (see FIG. 2). Notify that the search for (A)) has been entered. Thus, the VTR enters the fast-forward mode, and the tape sends the first program FE1 (Fig. 2A) to the playback head position at high speed.

In this state, the system control circuit 2 operates at step SP2.
To determine whether an index has been detected,
This judgment is repeated until a positive result is obtained. The index signal recorded in the track of the control pulse signal CTL is detected by the index detection circuit 2 (FIG. 1) when the duty ratio of the control pulse signal CTL changes, and the system control circuit 2 detects the next signal according to the detected signal. The step
Move to SP10 and switch the VTR to playback (PB) mode. Thus, the system control circuit 2 is in a state where the tape traveling speed by the tape drive device 3 is reduced to the normal speed and the video signal and the audio signal are reproduced by the signal processing circuit 4. Thus, the operator can confirm the image and sound of the head portion of the first program FE1 (FIG. 2 (A)) at normal speed.

In this state, the system control circuit 2 goes to the next step.
After moving to SP11, a judgment is made as to whether or not a predetermined time T has passed after the VTR entered the reproduction mode, and this judgment is repeated until a positive result is obtained. After a lapse of time T, the system control circuit 2 returns to step SP7 to fast forward VTR again (F
F) Switch to mode. Accordingly, the tape drive device 3 is again in the state of fast-forwarding the tape at a high speed, and the signal processing circuit 4 is returned to the state of muting both the image and the sound.

Thus, the VTR plays the original image and sound of the first program FE1 for the time T and then returns to the fast-forward (FF) mode again to play back the remaining programs of the first program FE1 at high speed. Is sent to enter the search state in which the portion in which the index signal IND2 of the second program is recorded is brought to the reproduction position at high speed. In the meantime, the system control circuit 2 proceeds to the next step SP8 to operate the index counter 22 to count "+1" and set the numerical value "2" indicating that the next program to be searched is the second program FE2. It is displayed on the fax counter 22. Then, subsequently to step SP9, the index detection circuit 23 enters a state of repeatedly determining whether or not a new index is detected.

In this state, when the index detection circuit 23 sends a detection signal to the system control circuit 2 due to the arrival of the index IND2 of the second program FE2, the system control circuit 2 again moves to step SP10 to reproduce the VTR (PB ) Switch the mode.

At this time, the tape drive device 3 drops the tape to the normal speed again, and the signal processing circuit 4 enters a state of reproducing the video signal and the audio signal until the system control circuit 2 detects the elapse of the time T at the next step SP11. The operator can confirm the image and sound of the head portion of the second program FE2.

In the same manner, the VTR sequentially cues the third, fourth programs FE3, FE4 ..., and sequentially reproduces the video and audio signals of the head portion at the normal reproduction speed for a predetermined time T. become.

When the operator finds a program he or she wants to watch as a result of sequential cueing in this manner, the stop switch 19 provided in the operation switch group 1 is operated to send a stop mode command signal to the system control circuit 2. Then, the system control circuit 2 interrupts the procedure of FIG. 3 to switch the VTR to the stop mode as a whole.

Further, when the tape is completely fed out and the tape end is detected separately, the tape end signal is given to the system control circuit 2 so that the system control circuit 2 interrupts the procedure of FIG. After switching, it automatically switches to rewind mode, thus rewinding the tape to the initial state and then stopping the VTR as a whole.

Here, the index detection circuit 23 having the configuration shown in FIG. 4 can be applied. That is, the control pulse signal CTL reproduced from the control pulse signal track by the fixed head 31.
Is obtained as a pulse signal S1 by alternately generating a rising differential waveform and a falling differential waveform through the amplifier circuit 32. This rising differential waveform represents a period of one cycle of the control pulse signal, and the waveform shaping circuit 33
The rectangular wave signal S2 that rises at the rising edge of S1 and falls at the falling edge is shaped and sent to the servo control circuit.

The rectangular wave signal S2 is converted into an averaged DC level signal S3 in the integrating circuit 34 and is given to the comparing circuit 35. Thus, the DC output level of the integrating circuit 34 is a rectangular wave signal.
When the duty ratio of S2 is 50 [%], a relatively high DC level output V ₁ is obtained, whereas when the duty ratio of the rising section of the rectangular wave signal S2 drops to 20 [%], the integrating circuit 34 level of the output signal S3 is reduced to extremely low levels V _2. A reference power supply 36 for generating a reference voltage corresponding to the level between the levels V1 and V2 obtained by the DC level signal S3 is connected to the comparison circuit 35, and thus the DC level output S3 when the duty ratio of the rectangular wave signal S2 decreases. Becomes lower than the reference voltage of the reference power supply 36, the index detection output signal S4 can be obtained at the output terminal of the comparison circuit 35.

According to the above configuration, the index signal is recorded at the beginning of many programs recorded on the tape and used as a cue signal during playback, and the VTR is fast-forwarded until the index signal of each program is obtained. By sending in the mode, the program recorded on the tape can be searched at the maximum speed that the VTR can acquire, and the VTR is normally played for a predetermined time after the index signal is detected. The contents of the program can be confirmed without error.

In the case of the above-described embodiment, the VTR is fast-forwarded in the fast-forward mode until the index is detected as described above with reference to FIG. 2B. However, instead of this, the VTR is fast-forwarded. However, the same effect as the above case can be obtained.

Next, in the case of the embodiment described above with reference to FIG. 2 (B), when the tape is fed in a section other than the normal reproduction (PB) mode, the tape is fed at a high speed in the fast forward (FF) mode (30 times the normal speed). I decided to send it by, but instead of this, the second
As shown in FIG. 6C, a medium speed feed reproduction (CUE) mode in which a tape is fed at a medium speed (about 10 times the normal speed) may be used. In this case, the system control circuit 2, as shown in FIG. 5 in correspondence with FIG. 3, instead of judging whether or not the fast-forward switch 13 is pushed at step SP4 in FIG. It is only necessary to determine whether or not the (CUE) switch 15 has been pressed and to switch to the medium speed feed reproduction (CUE) mode instead of switching to the fast forward (FF) mode at step SP7. By doing so, the same effect as in the above case can be obtained except that the search speed becomes slower as compared with the case of FIG. 2B by the decrease from the high speed to the medium speed.

Further, in this case, the present invention is applied to the case of feeding the tape in the forward direction, but instead of this, the present invention can be similarly applied to the case of feeding the tape in the rewinding direction. In this case, instead of determining whether or not the medium-speed feed / reproduction (CUE) switch 15 is operated in step SP4 of FIG. 5, it is determined whether or not the medium-speed rewind / reproduction (REV) switch 16 is operated. At the same time, instead of switching to the medium speed feed reproduction (CUE) mode at step SP7, it may be switched to the medium speed rewinding reproduction (REV) mode. Even in this case, the same effect as in the case of FIG. 2 (C) can be obtained.

Further, as in the case of FIG. 2 (B), instead of searching in the fast forward (FF) mode and checking the screen in the playback (PB) mode, the fast forward (FF) is performed as shown in FIG. 2 (D). The search may be performed in the mode and the screen may be confirmed in the medium speed feed reproduction (CUE) mode. In this case, the system control circuit 2 corresponds to FIG. 3 and, as shown in FIG. 6, in the case of FIG.
B) mode was switched, but instead of this, medium-speed feed playback (CU
E) The mode should be switched. In this way, you can check the image after cueing at medium speed (normal speed 20
The same effect as described above with reference to FIG. 2 (B) can be obtained except that the image quality of a reproducible image is deteriorated because it is performed at a medium speed. Since this is done, the search time as a whole can be shortened.

In the case of FIG. 2D, the search may be performed in the rewind (REW) mode instead of the search in the fast forward (FF) mode. Further, when the search is performed in the rewind mode as described above, the image may be confirmed in the medium speed rewind reproduction (REV) mode. Even in this case, the same effect as described above with reference to FIG. 2D can be obtained.

FIG. 2 (E) shows another embodiment of the present invention so that when the index is detected as a result of searching at a high speed, the program can be reproduced from the position where the index is added as fast and accurately as possible. It is what Incidentally, as shown in FIG. 7 (A), the nth program FE
When the index detection circuit 23 detects the index INDn of n, the integration circuit 34 of the index detection circuit 23 is actually
The output signal S3 of FIG. 4 changes so that it rises gently and falls gently as shown in FIG. 7B, and since the index signal INDn has a time width, this index signal INDn Program while detecting
The image of the head part of FEn may not be played back. Therefore, in the case of the embodiment of FIG. 2 (E), the tape fed in the fast forward (FF) mode is once switched to the medium speed rewind (REV) playback mode when the index is detected, and the tape is wound in the reverse direction. Back, which causes the index signal IND
After rewinding to the position of the image signal and audio signal corresponding to the start point of, the mode is switched to the playback (PB) mode again. By doing so, as shown in FIG. 7 (D), the head scanning is once passed past the start point of the index signal INDn,
After that, after returning to the start point, the playback mode can be restarted from that position.

In order to perform such an operation, the system control circuit 2 has the configuration shown in FIG. In FIG. 8, the parts corresponding to those in FIG. 3 are designated by the same reference numerals, and as shown in FIG.
And the processing procedure between SP11 and SP11 has the same configuration as that changed as follows.

That is, the system control circuit 2 resets the display of the index counter 22 to "0" after confirming that the cue playback (INS) switch 17 and the fast forward (FF) switch 12 have been pressed in steps SP1 to SP7. Then, in step SP7, the mode is switched to the fast forward (FF) mode. Thus, the tape is fed at a high speed. In this state, the system control circuit 2 moves to step SP21 and the output signal S4 (FIG. 7 (C)) of the index detection circuit 23 changes from logic "L" to logic "L". It is in a state of judging whether or not it has risen to "H". Eventually the index signal
When INDn arrives and the index detection circuit 23 performs the detection operation, the detection output signal S4 rises from the logic "L" to the logic "H" at the start of the nth program FEn.
At this time, the system control circuit 2 moves to the next step SP22 to operate the index counter 22 for "+1" count operation, and then moves to step SP23 to switch the VTR to the medium speed rewinding (REV) mode, and then to the step At SP24, it is in a state where it is judged whether or not the index detection signal S4 falls from the logic "H" to the logic "L".

The tape at this time is in the following state. That is, when the index detection signal S4 rises from "L" to "H" in step SP21, the tape is fed at high speed in the fast-forward mode as shown in FIG. Tape goes into a state of going too far, so medium speed rewinding (REV) at step SP23
When the mode is switched, the tape speed rapidly changes from the high speed to the speed "0", and then the tape is fed in the opposite direction to rise to the medium speed. Thus, as the tape is rewound at medium speed, the index INDn of the program FEn will be displayed.
Since the start time of is returned to the playback head position, step
A positive result is obtained at SP24, at which time the system control circuit 2 moves to step SP10 to switch the VTR to the playback (PB) mode.

The tape state at this time is as follows. That is, the tape that has been rewound at medium speed enters the reproduction mode at step SP10, and after the medium speed rewind (REV) speed is changed to the speed "0", the running direction is reversed and the tape is returned to the normal reproduction speed. Go up. However, the reverse speed difference in the running direction of the tape at this time is a conversion from the medium speed to the normal speed, so that the tape overrun amount in the rewinding direction can be made substantially small in practice.

In this way, when the system control circuit 2 enters the step SP10, the same step as described above with reference to FIG.
After it is judged at SP11 whether or not the time T has elapsed, the process returns to step SP7 and the tape is fast-forwarded to the index signal of the next program.

With the configuration shown in FIG. 2E, the tape is once rewound to the beginning position of the index signal for the program in which the index signal is detected as described above with reference to FIG. By doing
It is possible to reliably reproduce the video signal and the audio signal recorded at the head position of the cueed program, so that the operator can confirm the image more accurately.

In addition, in FIG. 2 (E), the modes of the system control circuit 2 are switched in the order of fast forward (FF) mode → medium speed rewind playback (REV) mode → playback (PB) mode → fast forward (FF) mode. However, instead of this, rewind (REW) mode → medium speed forward playback (CUE) mode → playback (P
Even if the switching is performed in the order of B) mode → rewind (REW) mode, the same effect as the above case can be obtained.

Further, as a modified example of FIG. 2 (E), when the running speed and direction of the tape are sequentially switched, the tape may be changed as shown in FIG. 2 (F). That is, fast forward (FF) mode → rewind (REW) mode → medium speed forward playback (C
UE) mode → playback (PB) mode → fast forward (FF) mode or rewind (REW) mode → fast forward (FF) mode ← medium speed rewind playback (REV) mode → playback (PB) mode → rewind You may make it switch in order of (REW) mode.
By doing so, the tape feed speed is alternately reversed and the running speed is gradually decreased, so that the tape overrun amount can be effectively reduced, and the playback start position can be accurately set at the beginning. It can be positioned at the beginning of the published program.

Further, in the above embodiment, the cue reproduction (INS) for instructing the system control circuit 2 of the cue reproduction mode.
A switch 17 is provided and this switch 17 (SP1) and other switches 13 and 15 for sending a tape at a high speed during search.
The cue playback mode was activated by pressing (SP4), etc., but instead of this, cue playback (IN
S) The switch may be activated by repeatedly pressing the switch, or the index recording switch 18 may be used for activation.

〔The invention's effect〕

As described above, according to the present invention, in the case where an image of desired contents is searched out and reproduced from the tape on which a large number of programs are sequentially recorded while the first speed tape is running at the normal reproduction speed. In addition, when the beginning of each program is checked and the recorded content of the head is confirmed, the rewinding is performed at a second speed that is faster than the normal playback speed and slower than the first speed, and the confirmation is performed. Since the tape is sent again at the first speed after the end of the period, the amount of tape overrun in the rewinding direction can be reduced, so that the search can be speeded up and the contents of each program screen can be confirmed accurately. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a video reproducing apparatus according to the present invention, FIG. 2 is a signal waveform diagram for explaining the operation mode thereof, and FIG. 3 is a configuration of the system control circuit 2 of FIG. FIG. 4 is a block diagram showing the detailed structure of the index detection circuit 23 of FIG. 1, FIG. 5 and FIG.
FIG. 7 is a flow chart showing another embodiment of the present invention, and FIGS. 7 and 8 are signal waveform diagrams and flow charts showing still another embodiment of the present invention. 1 ... Operation switch group, 2 ... System control circuit, 3 ...
… Tape drive, 4 …… Signal processing circuit, 11 …… Recording (REC) switch, 12 …… Playback (PB) switch, 13 ……
Fast forward (FF) switch, 14 …… Rewind switch (REW) switch, 15 …… Medium-speed feed playback (CUE) switch, 16 …… Medium-speed feed rewind playback (REV) switch, 17 …… Cue playback (I
NS) switch, 18 ... Index (IND) recording switch, 19 ... STOP switch, 21 ... Cue playback indicator, 22 ... Index counter, 23 ... Index detection circuit.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroyuki Kaimai 6-7 35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Takeshi Omoto 6-7 Kita-Shinagawa, Shinagawa-ku, Tokyo No. 35 within Sony Corporation (56) Reference JP-A-55-135383 (JP, A) JP-A-56-41571 (JP, A) JP-A-57-86177 (JP, A) JP-A-57- 147176 (JP, A) JP 57-158054 (JP, A) Actual development 57-195638 (JP, U)

Claims (1)

(57) [Claims] 1. A magnetic tape in which a video signal is recorded on a magnetic tape by continuously forming diagonal recording tracks, and a control pulse signal corresponding to the video signal is different from a region in which the video signal is recorded. Is recorded in the longitudinal direction at the end of the program, and a plurality of programs are sequentially recorded in the longitudinal direction on the recording track, and the duty ratio of the control pulse signal is changed at each head of the plurality of programs. In a video signal reproducing apparatus which records a program identification signal and reproduces the video signal recorded on the magnetic tape based on the control pulse signal, the program identification is performed by detecting a change in the duty ratio of the control pulse signal. A program identification signal detecting means for detecting a signal, the magnetic tape is run at a first speed higher than a normal reproduction speed, and the program identification signal is detected. Each time the program identifying signal is detected by the detecting means, the magnetic tape is wound up to a position corresponding to the start point of the program identifying signal at a second speed higher than the normal reproduction speed and slower than the first speed. After returning, the traveling speed of the magnetic tape is switched to a normal reproduction speed for a predetermined time to reproduce a recording signal near the head of the program corresponding to the program identification signal, and then the speed of the magnetic tape is changed to the first speed. And a control means for performing a repetitive operation for returning to the speed of 1., and the recorded contents of the video signals of a plurality of programs are confirmed by the repetitive operation of the control means.