JPS6295082A - Recording and reproducing device for video signal - Google Patents

Abstract

PURPOSE:To reduce a video signal having high picture quality by shifting a vertical synchronizing signal by the phase difference of the vertical synchronizing signal and a reproducing vertical synchronizing signal by extending a time base of a video signal to (n) times, inserting the vertical synchronizing signal, dividing into (n) pieces of a track to record, assemble and edit them. CONSTITUTION:During recording, the time base of the video signal is extended to two times, during the period of the vertical synchronizing signal from the first field to the fourth field, the vertical synchronizing signals of respectively different forms in sequence are inserted to become the recording video signal of two channels and a sylinder and a capstan are in phase synchronized with the control signal 17 of two frame period synchronizing in phase with the vertical synchronizing signal of the recording video signal to record the recording video signal. At the times of assembling and editing, if two fields are dislocated as a reproducing vertical synchronizing signal detecting pulse 18, a system shifts the vertical synchronizing signal of the recording video signal by two fields and a vertical synchronizing signal detecting pulse 16 has the same phase as the reproducing vertical synchronizing signal detecting pulse 18.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video signal recording and reproducing apparatus that expands the time axis of a wideband video signal, divides it into a plurality of tracks, records and reproduces the same.

Conventional technology Figure 2 shows a method of expanding the time axis of a video signal by n times and recording and reproducing one field unit onto a magnetic tape using a rotary multi-node for each of a pair of channels A and B on n tracks. This is the recording pattern on the magnetic tape when

In FIG. 2, 1 is a magnetic tape, and 2 is a recording track for a video signal. The Aij-th track is a recording track where the recorded video signal iA of the i-th channel of the ]-th frame is recorded on the magnetic tape using the i-th channel head A of the multi-head. The same applies to the Bij-th trunk.

For example, tracks A11 to A11 are tracks recorded at the same time within one field period by all layers of the rotating multi-heads of n channels of A; The A11th track is recorded within the first field period of the frame, and the A1° track is recorded within the first field period of the second frame. Furthermore, recorded video signals of N/2n horizontal scanning periods are recorded within one track. Here, N is the number of horizontal scans in one frame (NTSC-525, PAL/SECAM-6
25, high quality - 1125), n is the number of tracks recorded within one field period.

From now on, for simplicity, N=1125. This will be explained assuming that n:2.

Figure 3 shows the horizontal synchronization signal, vertical synchronization signal, and vertical synchronization signal detection pulse (the horizontal synchronization period in which the vertical synchronization signal is included) of the recording video signal recorded using the gutter on the A1 channel in the above case. FIG. In FIG. 3, 3 is a horizontal synchronizing signal, 4 is a vertical synchronizing signal, and 5 is a vertical synchronizing signal detection pulse. As shown in Figure 2,
1 fee + 425.

The number of horizontal scans of the recorded video signal in the field is 1, and the number of horizontal scans for every 5 vertical synchronizing signal detection pulses is 28 because -H'C is
There are cases of 1H and 282H, and the phase relationship between the horizontal synchronization signal and the vertical synchronization signal is such that four fields constitute one unit.

The recording device has a video signal of T B C%, which constitutes one unit of the four fields. FIG. 4 shows a timing diagram for recording and reproducing with a general video signal recording and reproducing apparatus. 6 is an internal reference vertical synchronization signal, 7
8 is an internal reference vertical synchronization signal detection pulse, and 8 is an internal reference control signal.

During recording, all vertical synchronization signals having different shapes are sequentially inserted into the vertical synchronization signal periods of the first to fourth fields of the human-powered video signal to form a recorded video signal, and a two-field period is synchronized in phase with the vertical synchronization signal. The control signal and the rotation detection pulse of the cylinder and capstan are synchronized, and all recorded video signals are recorded. At the same time, the control signal is recorded on a control track along the longitudinal direction of the magnetic tape.

During playback, the internal reference vertical synchronization signal 6. is generated from the internal reference synchronization signal generation circuit. Obtain an internal reference vertical synchronization signal detection pulse 7, an internal reference horizontal synchronization signal, an internal reference clock signal, and an internal reference control signal 8 with a 2-field period phase-synchronized with the internal reference vertical synchronization signal. The cylinder is controlled by phase-synchronizing the rotation detection pulse of the cylinder of the video signal recording and reproducing device, and the control signal recorded at the time of recording is reproduced as a reproduction control signal, and the internal reference control signal is phase-synchronized. control the capstan to obtain a playback video signal.

When performing assemble editing, the recorded video signal is processed in the same manner as during the above playback, using a vertical synchronization signal separated from the recorded video signal to be inserted in the assemble edit instead of the internal reference vertical synchronization signal 6 during playback. and the reproduced video signal are synchronized in phase, and the recording video signal is recorded from the assembly point.

Problems to be Solved by the Invention FIG. 5 shows a timing diagram when performing assemble editing. 9 is a vertical synchronization signal separated from the recorded video signal, 10 is a vertical synchronization signal detection pulse, 11 is a control signal phase-synchronized with the vertical synchronization signal 9, 12 is a reproduced vertical synchronization signal, 13 is a reproduction vertical synchronization signal detection pulse, 14 is a reproduction vertical synchronization signal detection pulse whose phase is two fields different from that of the reproduction vertical synchronization signal detection pulse 13, and 15 is a reproduction after assembly editing that occurs when the reproduction vertical 1υ1 signal detection pulse has the phase of 14. This is a vertical synchronization signal detection pulse.

In the conventional example shown in FIG. 5, although the control signal 11 and the reproduced vertical synchronization signal 12 are phase-synchronized, the vertical synchronization signal inserted into the video signal is recorded with the video signal even though the period is 4 fields. (Since both the playback control signal and the control signal 11 are signals with a two-field period, the phase of the control signal 11 may be affected by the deviation in the relative position between the cylinder and the magnetic tape in the recording/playback device at the start of playback.) Reproduction vertical synchronization signal detection pulses 13 and 14
Two phase modes can occur.

There is no problem if the playback synchronization signal detection pulse is 13, but if the input vertical synchronization signal detection pulse 1Q and the playback video signal are locked with a phase shift of about 2 fields and the playback synchronization signal detection pulse becomes 14, the assemble point When you assemble and edit from
The order relationship of v4→v1 is lost, as shown in the reproduced vertical synchronizing signal detection pulse 15, which causes problems in the operation of the TBC controlled using it.

If the period of the control signal is made equal to the period of the vertical synchronization signal, which is 7, the above problem will not occur, but the control system of the recording and reproducing device will become complicated, and the response speed of the control system will also be slow, resulting in high performance. This is a problem because it becomes impossible to reproduce the image quality video signal.

An object of the present invention is to provide a video signal recording and reproducing apparatus that solves these problems.

Means for Solving the Problems The present invention expands the time axis of a video signal by n times and inserts vertical synchronization signals having sequentially different shapes into the vertical synchronization signal periods of the first field to the second n field. Recording is divided into n tracks, and at the same time a control signal that is phase-synchronized with the vertical synchronization signal is recorded in the longitudinal direction of the magnetic tape, and when assembling and editing, the control signal is added to the vertical synchronization signal inserted into the recorded video signal. Reproducing the video signal by synchronizing a reproduction control signal obtained by reproducing the signal, detecting a reproduced vertical synchronization signal from the reproduced video signal, and detecting a phase difference between the vertical synchronization signal and the reproduction vertical synchronization signal. The video signal recording and reproducing apparatus shifts the vertical synchronizing signal by the phase difference to have the same phase as the reproduced vertical synchronizing signal, and maintains the order relationship of the vertical synchronizing signals even after assembly and editing.

Effect of the Invention The present invention has the above-described configuration, but since the relative positions of the cylinder and the magnetic tape at the start of reproduction are different from those at the time of recording, the phase of the control signal with a 2-field period and the reproduction vertical synchronization signal with a 2n-field period, for example, is If a phase shift of an integer multiple of two fields occurs in the relationship, by detecting the phase difference and shifting the control signal, no matter what the relative position of the cylinder and magnetic tape is at the time of the start of playback. The vertical synchronization signal of the recorded video signal and the reproduced vertical synchronization signal of the reproduced video signal can be completely synchronized in phase, and assembling and editing can be performed from any point in time. Furthermore, since the video signal is recorded and reproduced in units of 2n fields using a normal control signal having a period of 2 fields, a complicated control system is not required, and the response speed is fast and stability is good.

Embodiment FIG. 1 is a timing diagram of a video signal recording and reproducing apparatus according to an embodiment of the present invention. In the same figure, 1
Reference numeral 6 indicates a vertical synchronization signal detection pulse, 17 indicates a two-field cycle control signal during recording, 18 and 20 indicate reproduction vertical synchronization signal detection pulses detected from the reproduced video signal, and 19 and 21 indicate reproduction vertical synchronization detection pulses, respectively. 18 and 2o
Reproduction control signals 22 and 24 are reset pulses produced by extracting the first detection pulse of 4 field periods from reproduction vertical synchronization signal detection pulses 18 and 20, respectively; 23 and 25 are recording control signals This is a phase detection signal whose frequency is divided by half using the rising edge of 17 as an edge and reset by reset pulses 22 and 24, respectively.

Regarding the video signal recording and reproducing apparatus of this embodiment configured as described above, the number of horizontal scans of one frame of the video signal is 112.
The operation will be described below when the video signal is doubled during 5H1 recording.

During recording, the time axis of the video signal is expanded twice, and the shape of each vertical synchronization signal period (vertical synchronization signal detection pulse period) from the first field to the fourth field is sequentially different as shown in Fig. 6. A vertical synchronization signal is inserted to obtain a two-channel recording video signal, and the cylinder and cab stan are phase-synchronized with the control signal 17 with a two-frame period, which is phase-synchronized with the vertical synchronization signal of this recording video signal. Record.

During assembly editing, first the 7linder and capstan are phase-synchronized with the control signal 17 to reproduce the video signal, and then the recorded video signal is inserted from the assemble point, and one unit is made up of four fields. In order to reproduce the video signal by synchronizing the phase of the 2-field period control signal and the reproduction control signal, the reproduction vertical synchronization signal detection pulse is determined relative to the vertical synchronization signal detection pulse 16 depending on the positional relationship between the cylinder and the magnetic tape at the start of reproduction. Two phase modes can occur: 18 and 200. However, in either phase mode, the reproduction control signals 19 and 21 are in the same phase as the control signal 17.

The phase of the reproduced vertical synchronization signal detection pulse is the same as that of the reproduction vertical synchronization signal detection pulse 18 with respect to the vertical synchronization signal detection pulse 16.
When there is a two-field shift as shown in the figure, the control signal 17 is divided in half at its falling edge and reset by the reset pulse 22 selected as "Pl" of the reproduction vertical synchronization signal detection pulse 18. Phase detection signal 23
When latched by the R1 pulse of the vertical synchronization signal detection pulse 16, the latch output becomes High level. When the system detects that the latch output is at a high level, the system increments the vertical synchronization signal of the recorded video signal by two fields so that the vertical synchronization signal detection pulse 16 has the same phase as the reproduced vertical synchronization signal detection pulse 18. Make it.

When the reproduced vertical synchronization signal detection pulse has a phase such as 20, the reset pulse 24 and the phase detection signal become 26, and when the phase detection signal 25 is latched with the R1 pulse of the vertical synchronization signal detection pulse 16, The latch output becomes Low level.

In this case, the phases of the vertical synchronizing signal detection pulse 16 and the reproduced vertical synchronizing signal detecting pulse 20 match, and the phase softening of the vertical synchronizing signal of the recorded video signal is not performed. After the above operations are completed, assemble editing is started.

In this embodiment, the reset pulse need not be P1, but any reset pulse may be used as long as it is phase-synchronized with the reproduction vertical synchronization signal and can detect a two-field phase difference with the recording vertical synchronization signal 16.

Furthermore, in this embodiment, the case where the time axis of the video signal 'f is expanded by 2 times has been explained, but even if the time axis is expanded by 3 times or more, the phase difference between the recording vertical synchronization signal and the reproduction vertical synchronization signal can be eliminated using the same method. .

Further, although the recording control signal and the reproduction control signal have a period of two fields, they may have a period of one field, and phase difference detection may be performed for each field.

As described in detail, according to the present invention, a video signal is expanded in time by n times, and vertical synchronization signals having sequentially different shapes are generated in vertical synchronization signal periods from the first field to the second n field. Insert it, divide it into n trunks and record it,
At the same time, a control signal that is phase-synchronized with the video signal is recorded in the longitudinal direction of the magnetic tape, and when assembling and editing, the control signal recorded in the longitudinal direction of the magnetic tape is added to the vertical synchronization signal that is synchronized with the recorded video signal. reproducing the video signal by synchronizing a reproduction control signal obtained by reproduction, detecting a reproduction vertical synchronization signal from the reproduction video signal, detecting a phase difference between the vertical synchronization signal and the reproduction vertical synchronization signal, By shifting the vertical synchronization signal by the phase difference to make it have the same phase as the reproduced vertical synchronization signal, the order relationship of the vertical synchronization signals can be maintained even after assembly and editing. There is no need to consider the positional relationship of the cylinders.

In addition, since the control system of the recording/reproducing device can record and reproduce video signals in units of 2n fields using l+1 '1' (signals) with a normal 2-field period, a complicated control system is not required. The response speed is also faster and more stable than when controlled by a control signal with a 2n field period, so it is possible to reproduce a high-quality video signal.

As described above, the video signal recording and reproducing apparatus which expands the time axis of the video signal by n times and divides it into n sections for recording and reproducing is very effective in practical use.

[Brief explanation of drawings]

Fig. 1 is a timing diagram of an actual example of the video signal recording and reproducing device of the present invention, Fig. 2 is a recording pattern diagram of the video signal in which the time axis is expanded by in times and divided into n channels, and Fig. 3 is a recording pattern diagram of the recorded video signal. 4 is a synchronization signal timing diagram, and Fig. 4 is a video signal recording/playback timing diagram.
FIG. 5 is a timing diagram at the time of assembling and editing, and FIG. 6 is a vertical synchronization signal waveform diagram in this embodiment. 1...Magnetic tape, 2...Video signal recording track, 3...Horizontal synchronization signal, 4...
...Vertical synchronization signal, 5...Vertical synchronization signal detection pulse, 6...--Internal reference vertical synchronization signal, Complete...Internal reference vertical synchronization signal detection pulse, 8...-... Internal reference control signal, 9...Vertical synchronization signal, 1o...
... Vertical synchronization signal detection pulse, 11 ... Control signal, 12 ... Reproduction vertical synchronization signal, 13° 14.15
...Reproduction vertical synchronization signal detection pulse, 16...
・Vertical synchronization signal detection pulse, 17... Control signal, 18, 20... Reproduction vertical synchronization signal detection pulse,
19.21...Reproduction vertical synchronization signal, 22.24...°
...Lisenotohals, 23.25 --- Name of phase detection agent: Patent attorney Hiroshi Nakao and one other figure 1, figure 2, figure 4, figure 5, figure 6

Claims (1)

[Claims] The input video signal is time-expanded by n times, and vertical synchronization signals having sequentially different shapes are inserted into the vertical synchronization signal period of the 1st field to the 2nth field to form a recording video signal, and n times per unit time. recording on the magnetic tape into tracks, and at the same time recording a control signal in phase synchronization with the vertical synchronization signal in the longitudinal direction of the magnetic tape,
When assembling and editing, a playback control signal obtained by playing back a control signal recorded in the longitudinal direction of the magnetic tape is synchronized with a control signal that is phase-synchronized with a vertical synchronization signal of the recorded video signal. The vertical synchronizing signal of the period from the first field to the second nth field of the reproduced video signal is separated to obtain a reproduced vertical synchronizing signal, and the phase difference in units of two fields between the vertical synchronizing signal and the reproduced vertical synchronizing signal is determined. , the vertical synchronization signal is shifted by the phase difference to have the same phase as the reproduced vertical synchronization signal, and the order relationship of the vertical synchronization signals is maintained even after assembly and editing. recording and reproducing equipment.