JPH02185183A - Segment split recording system magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a video signal representing the content of an original picture even at the vari-speed reproduction by recording a control signal on a control track in a form identifying each segment, reading out the result in a desired order, and generating a reproducing video signal. CONSTITUTION:A control signal with a combination of a different duty ratio is recorded on a control track of a magnetic tape 15 at recording so as to identify a head of each frame and each segment of each field. Heads 17a, 17b scans on a magnetic tape 15 along a scanning locus at reproduction and a reproducing signal (a) is inputted to a memory 8 via a switch 2, an amplifier 1 and an A/D converter 3. The reproducing signal written in this way is sent from a readout address generating circuit 35. When the reproduced video signal is displayed on the screen, a picture able to identify sufficiently the content of the original picture is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device that enables good variable speed playback in a helical scan VTR that records one field of video signal by dividing it into n segments. It is.

[Conventional technology]

Fig. 7 is a perspective view showing the configuration around the rotary head of a conventional helical scan type VTR, Fig. 8 is a Y-plane view thereof, and Fig. 9 is a diagram showing the recording pattern of a magnetic tape at a normal speed. It is.

In the figure, (15) is a magnetic tape, (16) is a capstan, (17a) is a video head with an azimuth angle of A, (+7b) is a video head with an azimuth angle of B that is different from A, and (18) is a rotating drum. , (19) is the audio head, (20) is the control head, [21] is the audio track, (22) is the video track, (23)
is the control track. A segment recording method has been proposed as a method for recording broadband signals such as high-definition signals without changing the drum diameter with such a configuration. In other words, in the segment division recording method in which the rotation speed of the rotating drum and the speed of the magnetic tape are multiplied by n (n is an integer) in the configuration shown in FIG. 8, the relative speed between the magnetic tape and the head can be increased. The recording wavelength can also be made longer, making it possible to record broadband signals using current technology. FIG. 10 shows a tape pattern recorded with the rotational speed tripled in this manner. A1 in the diagram
．． A2. -... is the track recorded with the video head (17al), B1.B2... is the video head (+7b)
Indicates the track recorded with.

That is, among the signals of one frame, the signal of the first field is track A1. B2. The signal of the second field is divided into tracks B4.A4 and recorded. It is divided into A5.86 pieces and recorded.

[Problem to be solved by the invention]

When a magnetic tape recorded with such a pattern is played back at a tape speed different from the recording speed, for example, five times the recording speed, the scanning trajectory of the video heads (17a, (17b)) will be as shown in Figure 10. As shown in Figure 1+, the reproduced signal is a mixture of the signals of the first field and the second field.In the figure, A1.Δ2.
..., B1゜132, ... are respectively track A
1. △2. --B1. B2. - Indicates the signal reproduced from... Therefore, if this reproduced signal is displayed as is, there is a problem in that the content of the reproduced image cannot be easily identified.

This invention was made with the aim of solving the above-mentioned problems, and it is possible to obtain a normal reproduced image when a magnetic tape recorded using the segment division recording method is reproduced at a tape speed different from that at the time of recording. The object of the present invention is to obtain a magnetic recording/reproducing device that can perform the following steps.

[Means for Solving the Problems] A segment division recording type VTR according to the present invention includes a means for recording a control signal in a control track in a form in which each segment can be identified, and a means for recording the control signal in a form in which each segment can be identified, and a means for recording the control signal in a form in which the reproduced control signal is reproduced during reproduction. The present invention is characterized by comprising means for creating an identification signal for each segment based on the signal, writing the signal of each segment reproduced based on this signal into a memory, and reading it out in a desired order to create a reproduced video signal. .

[Operation] The start point of each segment can be identified from the format of the reproduced control signal. The memory reading means writes into the memory based on the segment identification signal created from this playback control signal,
The readout means reads out the signals of each segment from the memory at a predetermined timing so as to provide good image ambivalence.

[Embodiments of the invention]

FIG. 1 is a block circuit diagram showing an embodiment of the present invention.
(1) is a head amplifier that amplifies the reproduced video signal; (2)
is a head switch that switches between the video heads (17a) and (17b), (3) is an A/D converter that converts the playback video signal from A/D, (4) is a recording/playback switching switch, and (5) is a playback control. a head amplifier for amplifying the signal; (6) segment identification signal generation means for creating a signal for identifying each segment based on the reproduction control signal; (7) memory control means for controlling the memory based on the segment identification signal; (8) is a memory that stores the reproduced video signal; (9) is a reproduced signal processing means that performs various signal processing on the reproduced video signal; and (10) is a D/A converter for the processed main video signal. D/A converter, +
111 is a terminal for outputting a main video signal, (12) is an input terminal for a segment identification signal to distinguish each segment during recording, and (13) is a control for changing the form of the control signal to be recorded based on the segment identification signal. The signal generating means (14) is a recording control signal amplifier.

FIG. 2 is a block circuit diagram showing an example of the structure of the memory control means (7) and the memory (8), where (24) is a write address that generates the address when inputting the reproduced video signal to the memory (8). generation circuit, (25) is an input terminal for a fortune-telling address reset signal, (26) is an input terminal for a reproduced video signal, (27) is an input terminal for a write inhibit signal, (2)
8) to (30) are the first. Second. Input terminals for third segment identification signals c, d, e, (31) are 011 gates, (3
2), (33), and (34) are the first. Second. The first . Second. Third segment storage memory, (35)
A read address generation circuit generates an address when reading from the memory (8), and (36) is an input terminal for a read address reset signal.

Next, an explanation will be given of the operation when recording at 3x speed and recording at 5x speed in this embodiment.

During recording, the control track of the magnetic tape (15) contains control signals with different duty ratios, so that the beginning of each frame and each segment of each field are formed as shown in FIG. 3(b). is recorded.

FIG. 4 is a diagram showing output signal waveforms of various parts during 5x speed reproduction.

During playback, the heads (17a) and (17b) scan the magnetic tape (!5) with the scanning trajectory shown in FIG. 9, and transmit the playback signal a shown in FIG. ) and the memory (8) via the A/D converter (3).
).

On the other hand, the control signal b (shown in FIG. 4(b)) reproduced by the control head (20) is sent to the switch (4).
and the segment identification signal generating means (6) via the amplifier (5). Second. Third segment identification signals c, d, e (Fig. 4 (C), (d),
(e) shown), write address reset signal shift r (
(shown in Figure 4(f)), write inhibit signal h (shown in Figure 4(h)
) shown in the figure) and the fortune-telling address reset signal g (fourth
Figure (g) shown) is generated.

Memory (8) 1st. Second. Third segment storage memory (hereinafter referred to as "segment memory") (321, +
331. (34) includes a write address generation circuit (
head (17a), (17
The write address l (shown in FIG. 4 (β)), which is reset at the start of scanning of bl and increases sequentially from 0, and the OR
OR of the 1st, 2nd, and 3rd segment identification signals c, d, and e inputted to the gate (311) and the write-protection IL signal.
The first signal is input and the write inhibit signal is not input. Second. Only during the period when the third segment identification signals c, d, and e are input, the respective segment memories (32), +33), (3
Write in 4). FIG. 4 (ml(n), (o) shows the fj raw signal written in each segment memory.

The reproduction signal written in this manner is sent out from the read address generation circuit (35). At the same time as the playback signal which is reset at the first reading of the field and written to the segment memory (321, +331, +34) in the order of segment memories (321, +331. The stored playback signals are sequentially read out, and the playback video signal g shown in FIG. It is converted into a signal and output as a playback video signal from the output terminal (11). When one field is read out, the segment memories (321, (331, +341) are replaced with 14 in sequence starting from the oldest one. , the write and read operations for the next field are started.

The reproduced video signal obtained in this way is shown in FIG.
As shown in , the first segment of the first field is △1
．． Δ1. B4 (A1.84 is the signal one field before)
The second segment consists of A5. B2. A5 (A5
is composed of the signal of one field before), and the third segment is composed of the signal of B6. Since it is composed of A3°A3 video signals,
When this reproduced video No. 53 is projected on the screen, there are some parts that differ from the signal arrangement at the time of recording (see Figure 3 (a) or Figure 10), but the content of the original image can be identified in parts. You can get the image you want.

In the above embodiment, the duplex ratio of the control signal was changed so that the first segment of the frame and the three segments of each field could be identified, but the duplex ratio of the control signal was changed so that the first segment of the frame and the three segments of each field could be identified. The duty ratio may be changed, or the first and second fields and the three segments of each field may be distinguished, or a level difference may be given to the control signal instead of the duty ratio. .

In addition, as shown in FIG. 6, a first segment signal (shown in FIG. 6(a)) that can identify the first segment of a frame or field from a playback control signal (shown in FIG. 6(a)) is used.
b) Create the second and third segment identification signals (as shown in Figures 7(c) and (d)) in synchronization with the cycle of the control signal based on this signal below. It may also be configured such that each segment is identified by

In the above embodiment, a 2-channel 3-segment division recording method was explained, but a multi-channel segment division recording method in which a video signal is divided into m channels, further divided into n segments, and recorded by m heads. Similarly, the same effect can be obtained by recording the period of the control signal by changing the form of the control signal as in the first embodiment, with the signal period of one segment being one period.

It goes without saying that the variable playback speed is not limited to 5x speed.

[Effects of the invention] Below 1-. According to the present invention, the control signal is recorded on a recording medium in a form that allows identification of the beginning position of each frame, each field, or each segment, and in the reproduction system, each segment is read from the reproduced control number 13. An identification signal is created, +'J is written into the memory based on this segment identification No. 13, and the segment signals are read out from this memory in the desired order to output the video signal, so even during variable speed playback, the original This has the effect of providing a segment division recording type magnetic recording/reproducing device that can output a video signal representing the content of an image.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a block circuit diagram showing an example of the memory control means and memory configuration of this embodiment, and FIG. 3 is an explanation of control signals of this embodiment. 4 is a signal waveform diagram of each part of this embodiment, FIG. 5 is a diagram for explaining the procedure for loading old data into memory, and FIG. 6 is a segment identification signal which is one of the constituent elements of this invention. 7 is a perspective view of a conventional helical scan type VTR, FIG. 8 is a plan view thereof, FIG. 9 is a diagram showing the track pattern of the magnetic tape of this conventional example, and FIG. Figure 10 shows the track pattern of a magnetic tape recorded at triple speed using the segment division recording method using this conventional VTR. The figure shows a segment signal arrangement of an amphibian signal reproduced from this magnetic tape at five times the speed. (6)...Segment identification signal generation means, (7)...
-Memory control means, (8)--memory, +131...
・Control signal generation means, +241-... write address generation circuit, (311-OR gate, (32)
, (33), T34)...Segment storage memory, (35)...Read address generation circuit. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A magnetic recording/reproducing device that divides one field of video signal into n (n is an integer of 2 or more) segments and records them on a recording medium, the recording system having a recording system in which each segment is recorded on a recording track of the recording medium. means for recording a control signal in a form that can identify the first segment of a frame or field or each segment of each field; and means for creating a signal that identifies each segment of the reproduced signal from the control signal reproduced by the reproduction system; Segment division recording comprising means for writing signals of each segment into a memory based on this segment identification signal, and means for reading out the segment signals written into this memory or the written segment signals in a desired order in which the reproduced image can be identified. system magnetic recording and reproducing device.