JPS648955B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording medium for playback such as a video disk or a video tape, and a playback device such as a video disk player or a video tape recorder that uses the recording medium for playback. The present invention relates to a playback recording medium and a playback device that are particularly effective in the field of education.

An example of a recently developed Philips type optical disk player will be described with reference to FIGS. 2 at a constant speed of, for example, 1800 rpm, a beam 4 is projected onto the disk 1 from a beam projection device 3, and the beam projection device 3 is further sent in the radial direction of the disk by a feeding device 5 onto the disk. It is configured to read signals while scanning the beam 4 in a spiral manner. More specifically, the laser beam emitted from the laser light source 6 passes through a concave lens 7, a polarizing beam splitter 8, a 1/4λ plate 9,
A beam 4 for reproduction is converged through a rotary mirror 10 for minute movement of the light beam and a condenser lens 11, and this beam 4 is projected onto the disk 1.
When the recording track of the disk 1 is scanned with the beam 4, the reflected beam 12 corresponds to the presence or absence of recording signals.
is obtained, and this reflected beam 12 is passed through the condenser lens 1
1. Photodetector 13 for recording signal detection via rotating mirror 10, 1/4λ plate 9, and beam splitter 8
The signal is then converted into an electrical signal and sent to the demodulation circuit. Although not shown in FIG. 1, a tracking control device and a focus control device are also provided.

As shown in FIGS. 2 and 3, the disk 1 used in the apparatus shown in FIG. 1 is generally one in which, for example, an NTSC video signal is recorded on a spiral track 15 using optical recesses or pits 14. be.
The width of the pit 14 in this disc 1 is, for example, approximately 1 μm, the depth of the pit is approximately 1/4λ (here, λ is the wavelength of the laser beam), and the length of the pit is the inner and outer sides in the case of a video disc. There is a difference depending on the size, for example, 1.5 to 6 μm. A video disc 1 on which information signals are recorded with such pits 14 generally includes a transparent resin layer 16 having an uneven surface corresponding to the pits 14 and a reflective film 17 coated on the uneven surface of the resin layer, as shown in FIG. and a protective film 18 that protects the reflective film.
It consists of

The diameter of the reproducing beam 4, which is illustrated in FIG. 2, is larger than the width of the pit 14, and when scanning the pit 14, the reflected light inside the pit and the reflected light outside the pit cancel each other out. When an area where the pit 14 is not provided is scanned, no cancellation occurs and the reflected output becomes large. Therefore, the intensity of the light changes depending on the presence or absence of pits, making it possible to read pits.

Incidentally, on the disk 1, a first field (odd field) signal of, for example, an NTSC television signal is recorded on half the circuit of the track 15, and a second field (even field) is recorded on the remaining half circuit. That is, the first
A field signal is recorded, and a second field signal is recorded between point B and point C, and one frame is recorded in one round. For this reason, since there is a vertical blanking period every half cycle, special playback such as still picture playback, slow motion playback, quick playback, etc. can be easily performed. Such special playback is performed by performing an operation for special playback when a screen on which special playback is desired appears. Even with this method, special playback is of course possible, but the user has to decide whether or not to perform special playback at his/her own discretion and operate the operation. The disadvantages are that you have to be careful, that the operation is cumbersome, and that you may make a mistake in deciding whether to perform special playback or not.
I just mentioned the video disk system,
A similar problem occurs when playing back a recorded video tape or the like.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a recording medium for reproduction and a reproduction apparatus that can accurately convey recorded contents to a user and reduce the burden on the user.

A recording medium for achieving the above purpose continuously records video signals so that normal playback can be performed, and also sends a special mode instruction signal and special mode playback time instruction signal corresponding to the portion desired for special playback. The invention is characterized in that a special reproduction control signal including the following is recorded in advance.

The playback device according to the present invention continuously records video signals so that normal playback can be performed, and also includes a special mode instruction signal and a special mode playback time instruction signal corresponding to the portion desired to be played back. The device utilizes a reproduction recording medium on which a special reproduction control signal is recorded in advance, and includes a recording signal reading device for reading the recorded signal from the reproduction recording medium, and a recording signal reading device for reading the special mode instruction signal from the signal read by the reading device. A special mode instruction signal detection circuit detects the special mode reproduction time instruction signal, a special mode reproduction time instruction signal detection circuit detects the special mode reproduction time instruction signal from the signal read by the reading device, and a special mode reproduction time instruction signal detection circuit detects the special mode reproduction time instruction signal from the signal read by the reading device. The recording signal reading device is controlled to read the video signal in a playback mode, and when the special mode instruction signal is detected by the special mode instruction signal detection circuit, the reading device is controlled by the special mode instruction signal. The reading device is operated in a special playback mode, and in response to the special mode playback time instruction signal detected by the special mode playback time instruction signal detection circuit, the reading device is operated in a special mode only for the time specified by the special mode playback time instruction signal. The apparatus is characterized in that it is configured to include a reproduction mode control circuit for returning to normal reproduction mode after operating in reproduction mode.

According to the invention of the recording medium and the invention of the playback device, the special mode instruction signal and the special mode playback time instruction signal are used to automatically select a portion where the special mode is desired for only the time specified by the special mode playback time instruction signal. This makes it possible to perform accurate and accurate reproduction. That is, it is possible to reproduce a necessary part in a special mode for a necessary time without any special operation by the user.

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

A video disc according to an embodiment of the present invention also includes:
The apparatus is constructed as shown in FIGS. 1 to 3, and is configured to be reproduced by the apparatus shown in FIG. 1, but the signals recorded here are different. That is,
The disk in this example simply accepts NTSC video signals.
Without FM recording, a special playback control signal is recorded in the vertical blanking period of the field (second field) before the frame for which special playback is to be performed or the second field of the frame for which special playback is to be performed. FIG. 4 shows an example of a video signal recorded on a disk. In this case, the equivalent pulse period T ₁ is 3H (where H is one horizontal scanning time of 63.5 μs, for example), and the vertical synchronization pulse period is 3H. T ₂ and equivalent pulse duration T ₃ of 3H
and a vertical sync pulse period within a vertical blanking period T consisting of, for example, a 12H horizontal sync pulse _T4 .
The special reproduction control signal 20 is recorded in the equivalent pulse period T ₁ before T ₂ . As explained in FIG. 2, the vertical blanking period T exists in both the first field scan and the second field scan, so even if the special playback control signal is recorded in either field scan period, However, in this embodiment, recording is performed in the vertical blanking period T of the second field of the frame for which special playback is desired or the frame immediately before the frame for which special playback is to be started, and in the vertical blanking period T of the first field. is not recorded.

The special playback control signal includes the first field indicator signal 21 recorded at the white level and signals 3 to 4.
It consists of a special mode instruction signal 22 recorded as a digital signal of bits, and a special mode reproduction time instruction signal 23 recorded as a digital signal of 3 to 4 bits. The first field indicator signal 21 is recorded in the first H section of the equivalent pulse period _T1 , and the special mode instruction signal 22 and special mode playback time instruction signal 23 are recorded in the third H section. . The above-mentioned first field indicator signal 21 is used to ensure that special playback starts from the first field, and also serves as a termination signal (end marker) for normal playback.
It is also used as a. In addition, the above special mode instruction signal 22 is used for still image (still) playback, slow motion playback, quick motion playback,
This is a signal instructing the start of a special mode such as reverse playback. Further, the above-mentioned special mode playback time instruction signal 23 is a signal for determining the time for performing special mode playback.

A video disc on which the above-mentioned special playback control signals are recorded is produced by using, for example, a recording circuit shown in FIG. That is, the NTSC video signal applied to the input terminal 24 from a VTR or video camera, etc. is amplified by the amplifier 25, and then sent to the second field vertical blanking period timing pulse generator 26, where it is sent to the second field vertical blanking period timing pulse generator 26. Detect the vertical blanking period at t 1 of the first H, that is, t ₁ in FIG.
A 1H timing pulse corresponding to ~ _t2 and a 3H timing pulse corresponding to the third H, ie, _t3 to _t4 , are formed. On the other hand, while monitoring the NTSC video signal, if, for example, a frame desired for still image reproduction arrives, a special reproduction command signal is generated, and the first field indication signal generator 27 generates a first field indication signal. This first field indication signal is of course sent out in synchronization with the 1H timing pulse obtained from the timing pulse generator 26.
Further, the special mode instruction signal generator 28 generates a still image reproduction mode instruction signal corresponding to the still image reproduction information in synchronization with the 3H timing pulse applied from the timing pulse generator 26. Further, the special mode playback time instruction signal generator 29 indicates the desired time for still image playback, for example, 2 minutes, 5 minutes, etc.
A special mode reproduction time instruction signal corresponding to specified time information such as minutes, 10 minutes, etc. is generated in synchronization with the 3H timing pulse given from the timing pulse generator 26. At this time, of course, the clock relationship between the special mode instruction signal and the special mode playback time instruction signal is taken into account and both signals are sent out.

The three signals obtained as described above are added in an adder 30 and then added to the NTSC video signal in an adder 31, resulting in a composite video signal including the control signal shown in FIG. The recording of the NTSC video signal to which the special playback control signal 20 is added to the disk is performed using the FM recording method as in the conventional art.

Now, if you record the still image playback mode instruction signal,
Even if you want to obtain the same or similar information on a cathode ray tube at a predetermined time as the screen you want to play a still image,
There is no need to record continuously. A screen that is substantially the same as a static screen obtained by reproducing a continuous recording can be obtained with a single frame static screen. Therefore, without continuous recording of static screens,
Move on to the next record. Continuing to record in this way, if you come to a point where you want special playback again, perform the same operation. If signals for slow-motion playback or quick-motion playback are to be recorded, these control signals are recorded in the frame at which playback starts or in the frame immediately before the start of playback.

FIG. 6 shows a part of an apparatus for performing reproduction using a disk on which a special reproduction control signal is recorded as shown in FIG. The parts not shown in Fig. 6 are constructed in the same way as in Fig. 1, and the signals shown in Fig. 4 are read from the disk by the device shown in Fig. 1. . Therefore, the device of FIG. 1 can be called a signal reading device. The signal read by the device of FIG. 1 is demodulated by the demodulator 32 of FIG.
The signal is sent to the field vertical blanking period detection circuit 33. Second field vertical blanking period detection circuit 33
are the composite video signal from t 1 to t ₂ and _{t 3 in} FIG. 4 during the vertical blanking period of the second field scanning period.
~t This is to separate and detect the signals from the ₄ sections. Furthermore, a first field indicator signal detection circuit 34, a special mode instruction signal detection circuit 35, and a special mode reproduction time instruction signal detection circuit 36 are provided as special reproduction control signal detection circuits. To further explain these, the first field indication signal detection circuit 34
detects the first field indicator signal 21 shown in FIG. 4, indicates that the next field is the first field, indicates that special playback is to be started from the next field, and ends normal playback. A signal indicating the disc player's playback mode control circuit 3
7. When the control circuit 37 receives the output from the first field indicator signal detection circuit 34, it sends out a signal to stop normal reproduction and at the same time sends out a signal to start the mode designated by the output of the special mode instruction signal detection circuit 35.

The special mode instruction signal detection circuit 35 detects the special mode instruction signal 22 in the period t ₃ to _{t 4} shown in FIG. 4, and applies it to the control circuit 37.
If a still image reproduction mode signal is detected, the mode is changed in the control circuit 37 during the vertical blanking period specified by the first field indicator signal, and for example, in FIG. A signal is generated that moves the point. and,
Reproduction from point A to point C is repeated for a predetermined period of time.

The special mode playback time instruction signal detection circuit detects the special mode playback time instruction signal 23 recorded in the period t ₃ to _{t 4} in FIG. It is something. The control circuit 37 is a time instruction signal detection circuit 36
It operates to perform special playback only for the period determined by , and when the predetermined time elapses, it switches to the normal playback mode control state.

A special playback mode reset circuit 38 is provided in case the special playback mode is to be ended earlier than a predetermined time. When a reset signal is generated from this reset circuit 38,
The special mode playback state is canceled and the mode changes to normal playback mode.

The control circuit 37 is a circuit that controls the mode of the video disc as described above, and more specifically,
This is a circuit for controlling the rotating mirror 10 shown in FIG.
The rotating mirror 10 has a structure similar to a galvanometer, and is coupled to a moving coil, and when the current in the moving coil changes, the rotating angle changes, displacing the beam 4 in the radial direction of the disk 1. . Thus, for example, the synchronization pulse period in FIG.
When a jumping pulse is applied to the moving coil during an equivalent pulse period T ₃ or a horizontal synchronization pulse period T ₄ after T ₂ , the rotating mirror 10 rotates, and the beam 4 is moved, for example, from point C to point A in FIG. Move to. Such beam shifting mechanisms are well known in optical video disc players and will not be described in further detail.

As is clear from the above, according to the video disc and video disc player of this embodiment,
Since the special playback control signal is pre-recorded in correspondence with the part where special playback is desired, no matter how many people use it, the special playback state will be activated at that part. Therefore, the intention of the record editor can be completely conveyed to the user. Therefore, the user or handler does not have to think about where it is desirable to perform special reproduction, and can concentrate his/her attention elsewhere.

Furthermore, when the special reproduction mode is set to the still image reproduction mode, an effect equivalent to an increase in the recording capacity of the recording medium can be obtained. For example, if still image information is continuously recorded, the same or nearly the same video signal must be repeatedly recorded over tens of seconds or minutes, and as a result, a recording medium corresponding to this will also be required. However, in this embodiment, even if the same playback screen is requested for a long time, it is sufficient to record only one frame or several frames worth of video signals.

Furthermore, in this embodiment, since the first field indicator signal is recorded, it is possible to always start the reproduction from the first field.

Furthermore, since the special mode playback time instruction signal is recorded, it is possible to automatically return from special mode playback to normal playback.

Further, in the embodiment, since the special playback control signal is recorded immediately before the part to be special played or during the last vertical blanking period of that part, switching to the special mode can be easily achieved.

Furthermore, since the special reproduction control signal is recorded on the front porch of the vertical synchronizing pulse, it is possible to switch modes on the back porch of the same vertical blanking period.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be further modified. For example, instead of recording the special playback control signal in the vertical blanking period immediately before or within the part where special playback is desired, it is possible to record the special playback control signal in the vertical blanking period one or several frames before or in a period in the vicinity thereof. good. In this case, the system may be designed so that the mode switching signal is generated after a predetermined period of time has elapsed since the detection of the special playback control signal. Also, if you want to perform special playback on this part after normal playback, a special playback control signal is recorded during the last vertical blanking period of the part you want to perform special playback, and if necessary, the beam is returned to the special playback starting point. It is sufficient to record the control signals. Or, if you want to record a special playback control signal at the beginning of the part you want to perform special playback, record information that will prevent the mode change immediately, and after normal playback ends, return the beam to the special playback start point and perform special playback. Let's move on. Furthermore, the demodulator 32 in FIG. 6 may also be used as a demodulator for a television receiver. Further, in FIG. 6, three detection circuits 34, 35, and 36 are provided via the second field vertical blanking period detection circuit 33, but three signals 21, 36 are provided from the demodulated video signal.
22 and 23 may be detected directly.
Alternatively, instead of recording the three signals 21, 22, and 23 in independent formats, they may be recorded in a mixed format, and the information of each signal may be extracted after detection. Furthermore, the present invention is not limited to video discs, but can also be applied to video playback systems such as video tapes and video tape recorders.

[Brief explanation of the drawing]

FIG. 1 is a front view illustrating an optical video disc player, FIG. 2 is a plan view illustrating a video disc, FIG. 3 is a partially enlarged sectional view of the video disc, and FIG. 4 is a diagram illustrating the present invention. FIG. 5 is a block diagram showing the recording circuit, and FIG. 6 is a block diagram showing the control section of the playback device. be. In the symbols used in the drawings, 20 is a special playback control signal, 21 is a first field indicator signal, 22 is a special mode instruction signal, 23 is a special mode playback time instruction signal, and 34 is a first field indicator signal detection circuit. , 35 is a special mode instruction signal detection circuit, 36 is a special mode playback time instruction signal, and 37 is a playback mode control circuit.

Claims (1)

[Scope of Claims] 1. A video signal is continuously recorded so that normal playback can be performed, and a special mode instruction signal including a special mode instruction signal and a special mode playback time instruction signal corresponding to the portion desired to be played back is recorded. A recording medium for reproduction, characterized in that a reproduction control signal is recorded in advance. 2. The recording medium for reproduction according to claim 1, wherein the special mode instruction signal is a still image reproduction mode instruction signal. 3. The special playback control signal according to claim 1 or 2, wherein the special playback control signal is recorded in or near the vertical blanking period of the video signal for which special playback is desired or the video signal preceding it. Recording medium for playback. 4. The special playback control signal is recorded in the vertical blanking period of the second field scanning period of the frame in which the special playback is to be started or the frame immediately before the start of the special playback.
Recording medium for playback as described in section. 5 Continuously record the video signal so that normal playback can be performed, and also record in advance a special playback control signal including a special mode instruction signal and a special mode playback time instruction signal corresponding to the part where special playback is desired. A recording signal reading device that reads a recorded signal from the recording medium for reproduction, and a special mode instruction signal detection device that detects the special mode instruction signal from the signal read by the reading device. a special mode playback time instruction signal detection circuit for detecting the special mode playback time instruction signal from a signal read by the reader; and a special mode playback time instruction signal detection circuit for detecting the special mode playback time instruction signal from the signal read by the reading device; controlling the reading device to read; when the special mode instruction signal is detected by the special mode instruction signal detection circuit, operating the reading device in a special playback mode instructed by the special mode instruction signal; In response to the special mode playback time instruction signal detected by the special mode playback time instruction signal detection circuit, the reading device is operated in the special playback mode only for the time specified by the special mode playback time instruction signal, and then normal playback is performed. A playback device comprising: a playback mode control circuit for returning to a mode. 6. The playback device according to claim 5, wherein the recording medium is a video disc. 7. The reproducing apparatus according to claim 5, wherein the recording medium is an optical disc. 8. The reproducing apparatus according to claim 5, wherein the recording medium is an optical video disc.