JPH03183283A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a track at an editing point from being overlapped caused by the disconnection due to the bending of a track when electronic edition is performed by dividing a signal into ((MXN)-A) recording signals, recording every N signals sequentially for M times, recording (N-A) signals only at the boundary of one frame period, and forming an unrecorded part on a recording medium only at the boundary. CONSTITUTION:Three multiplex signals are outputted by dividing a digital video signal in one frame period into quingue partite signal at a signal dividing circuit 3, and they are supplied to recording magnetic heads 6-8. At a period t1, a division signal 1 is recorded on a recording track T1, and a division signal 2 on a recording track T2, and a division signal 3 on a recording track T3. Next, at a period t2, a division signal 4 is recorded on a recording track T4, and a division signal 5 on a recording track T5. A guard band is formed without recording the signal on the next recording track T6, and the recording of one frame is completed. The problem of the disconnection due to the bending of the track can be solved with the guard band.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a recording and reproducing device for recording and reproducing video signals.
This is particularly effective for recording narrow trunks.

In the prior art video tape recorder (VTR), a recording medium,
As the performance of magnetic heads improves, recording density increases,
Narrow trunk recording with a smaller track pitch is now possible. However, due to recording track curvature caused by mechanical precision, etc., there is a limit to how small the track pitch can be in order to ensure tape compatibility. In order to solve this problem of track curvature, there is a method in which a piezoelectric element or the like is used to swing a magnetic head in the track width direction to follow the track curvature, thereby achieving normal playback during tape interchange.

Problems to be Solved by the Invention Although the above-described method can solve the problem of track curvature during playback, the following problems arise during electronic editing regarding track curvature during recording.

Electronic editing usually requires accurate editing on a frame-by-frame basis, and it is necessary to accurately connect one recorded part to another. However, if the VTR on which the original recording was made is different from the VTR on which electronic editing is being performed, the track curvature changes discontinuously before and after the editing point, resulting in overlapping trunks at the editing point track, making it difficult to play the edited tape. There is a problem in that image distortion occurs when

In view of the above problems, it is an object of the present invention to solve the problem of image disturbance at an editing point due to mismatch in curvature between a previously recorded track and a newly recorded track during electronic editing during narrow track recording.

Means for Solving the Problems In order to solve the above problems, the recording and reproducing apparatus of the present invention has the following features:
The video signal of the frame period is N×M−A (N is a natural number,
dividing means for dividing the divided signals into a plurality of divided signals (M is a plurality and A is a number equal to or less than N); and dividing the divided signals into N divided signals M times and sequentially records them on a plurality of adjacent recording tracks on a recording medium. ,
The recording and reproducing means records N-A divided signals only at the boundaries of one frame period, and forms an unrecorded portion on the recording medium only at the boundaries.

A video signal of one frame period, which is a basic unit period during effect electronic editing, is divided into N×M−A recording signals by a dividing means. Next, the recording/reproducing means sequentially records these recording signals on a plurality of adjacent recording tracks on the recording medium in M times of N recording signals, but NA recording is performed only at the boundary of l frame period. Then, only this boundary forms an unrecorded portion on the recording medium. This unrecorded portion serves as a guard band between frames, and can eliminate the overlapping of trunks at editing points due to the discontinuity of track bending during electronic editing as described above.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the recording/reproducing apparatus of the present invention. In Fig. 1, 1 is a video signal input terminal for manually inputting a video signal, 2 is an AD converter that converts the video signal into an analog/digital signal to obtain a digital video signal, and 3 is an AD converter that divides the digital video signal to produce three multiplexed signals. 4 is a sync signal separation circuit that separates the sync signal from the digital video signal; 5 is a control signal generation circuit that generates a control signal based on the sync signal; 6 to 8 are multiplexed signals onto a magnetic tape; To the recording magnetism to record, throat, 9-1
Reference numeral 1 denotes a reproducing magnetic head' for reproducing multiplexed signals from a magnetic tape, 12 a signal synthesis circuit for synthesizing three reproduced multiplexed signals to obtain a reproduced digital video signal, and 13 converting the reproduced digital video signal from digital to analog. A DA converter 14 for obtaining a reproduced video signal is a video signal output terminal for outputting a reproduced video signal.

The operation of the embodiment will be explained based on FIG.

A video signal is applied to an AD converter 2 via a video signal input terminal 1, and subjected to analog-to-digital conversion to obtain a digital video signal. Next, this signal is given to a signal dividing circuit 3 and a synchronizing signal separating circuit 4. In the synchronization signal separation circuit 4, the synchronization signal is separated and given to the control signal generation circuit 5, and is used for timing synchronization of the control signal generation circuit 5.

A control signal is generated from the control signal generation circuit 5 and is applied to the signal division circuit 3 and the signal synthesis circuit I2.

The operation of the signal division circuit 3 is controlled by this control signal, and the digital video signal of one frame period is divided into five to obtain five divided signals, which are time-division multiplexed at the timing described later and output three multiplexed signals. Then, to the recording magnetism/nod 6
Give to ~8. These multiplexed signals are then recorded onto the magnetic tape by the recording magnetic heads 6-8.

FIG. 3 is an explanatory diagram showing the rotating cylinder and head arrangement. Three recording magnetic heads 6 to 8 are arranged close to each other as shown in the figure, and three multiplexed signals can be recorded simultaneously. , three recording tracks are formed on the magnetic tape by one rotation of the rotating cylinder.

FIG. 4 is a timing diagram illustrating the timing relationship of each part signal in FIG. 3 shows three multiplexed signals output from 3.

Note that the numbers shown in the figure indicate five divided signals. As shown in the figure, the five divided signals of the digital video signal (a) are time-division multiplexed into three multiplexed signals, and the three divided signals 1 to 3 are divided into three divided signals in period t1, and the two divided signals are divided into two divided signals in time t2. Signal 4.5 is output, and there is no signal only during period t2 of multiplexed signal (d).

FIG. 2 is an explanatory diagram showing the arrangement of recording tracks on the tape. Then, divided signal 1 is placed on recording track T1,
Divided signal 2 is recorded on recording track T2, and divided signal 3 is recorded on recording track T. Next, in period t2, divided signal 4 is recorded on recording track T4, and divided signal 5 is recorded on recording track T. The next recording track T6 forms a guard band with no recording, and recording for one frame period ends. Then, recording for the next one frame period starts from recording track T7.
The same is done for T and □. As a result, a guard band is formed between adjacent tracks between frames, and this guard band can solve the problem of discontinuity of track bending. FIG. 5 is an explanatory diagram showing the track arrangement on the tape when discontinuity of track bending occurs during electronic editing. In the figure, recording trunks T1 to T indicate the previously recorded green portions, and recording tracks T7 and after indicate newly recorded portions.
As shown in the figure, even if there is discontinuity in track bending, no track overlap occurs. FIG. 6 is an explanatory diagram showing the recording track arrangement in a discontinuous portion of track bending, where the broken line indicates the recording track when there is no trunk bending, and Q is the maximum deviation from linearity indicating the degree of track bending; G is the Girt band width (equal to the track pitch P in this embodiment). From the figure, if Q is less than half of G, no track weight occurs. However, if the track pitch P is further reduced to achieve higher density recording, Q
It is conceivable that it will be more than half of (=P).

In this embodiment, the above A is assumed to be 1, but this A means the number of unrecorded tracks, and by increasing this A, the unrecorded portion, that is, the guard band width G, is increased, and Q is increased by G. It is possible to reduce it by half or less. Therefore, A may be determined to satisfy Q<G=AP.

The above is the explanation of the operation during recording, and next the operation during reproduction will be explained. During reproduction, three multiplexed signals recorded on the magnetic tape are reproduced by the reproduction magnetic heads 9 to 11 and applied to the signal synthesis circuit 12. Signal synthesis circuit 1
2, the divided signals included in these multiplexed signals are synthesized to obtain the reproduced digital signal shown in FIG. 4(e), and the DA
to the converter 13.

The DA converter performs digital-to-analog conversion on the reproduced digital signal to obtain a reproduced video signal, which is output to the video signal output terminal 14.

The signal dividing circuit 3 in this embodiment converts a digital video signal (a) into three multiplexed signals (b) as shown in FIG.
) to (d), this circuit consists of a memory and a memory control circuit, stores one frame period of digital video signals in the memory, and reads out each divided signal at the timing shown in Figure 4. Three multiplexed signals are thereby obtained. The signal synthesis circuit is similarly configured with a memory and a memory control circuit, and a reproduced digital video signal is obtained by storing three reproduced multiplexed signals of one frame period in the memory and sequentially reading out the five divided signals. .

The above is the explanation of this embodiment. In this embodiment, the case where the above-mentioned N, which means the number of multiplexed signals, is 3, but other numbers can be realized in the same way.

Further, although the case where M, which means the number of divided signals multiplexed into one multiplexed signal in one frame period, is 2 has been described, it can be similarly realized with other numbers as long as 20M is 2 or more.

Effects of the Invention According to the present invention, it is possible to solve the problem of disturbances in reproduced images due to track overlap at editing points during electronic editing, and to easily realize narrow track recording.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a recording/reproducing apparatus according to the present invention, FIG. 2 is an explanatory diagram showing the arrangement of recording tracks on a magnetic tape, FIG. 3 is an explanatory diagram showing the arrangement of a rotating cylinder and a head, and FIG. 5 is an explanatory diagram showing the arrangement of recording tracks on a magnetic tape. FIG. 6 is an explanatory diagram showing the arrangement of recording tracks near an editing point. 3...Signal division circuit, 4...Synchronization signal separation circuit, 5...Control signal generation circuit, 6-8.
...Magnetic head for recording.

Claims (1)

[Claims] A dividing means that divides a video signal of one frame period into N×M−A (N is a natural number, M is a plurality, and A is a number equal to or less than N) divided signals, and a plurality of adjacent recording tracks on a recording medium. On the top, the divided signals are divided into N times M times and recorded sequentially, and N-A divided signals are recorded only at the boundary of one frame period, so that an unrecorded portion is formed on the recording medium only at the boundary. 1. A recording and reproducing device comprising a recording and reproducing means.