JPS63280582A - Video signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify the structure of a head and to make the tilled device high in performance by recording desired 2 fields separately on each track adjacent to a rotary recording medium one by one field, reproducing each adjacent track to attain still picture reproducing by frame. CONSTITUTION:One of the desired 2 fields is recorded over one truck without missing on a rotary recording medium 1 and the other field is recorded completely over the entire adjacent track to the said track without missing. At the time of reproduction, the two adjacent tracks on the rotary recording medium 1 are completely reproduced and scanned respectively before and after the truck feed period of the head 2, and no missing exists from each track and the field is reproduced without missing. By outputting the field alternately repetitively, a video signal possible for still picture reproduction is obtained by the frame. Thus, the structure of the head 2 is simplified and the performance is improved to obtain high-picture quality still picture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal recording and reproducing device suitable for still image reproduction.

[Conventional technology]

As video signal recording and reproducing devices for still image playback, devices using disk-shaped magnetic recording media called video floppies (hereinafter referred to as video floppy devices) have recently attracted attention. Electronic still camera published in Journal of Television Society, Vol. 39, No. 9 (1)
985) pp.

756-776. However, recently, video floppy devices are expected to be used not only in electronic still cameras but also in various applications for convenient video files. A conventional video floppy device will be described below.

In such a device, a large number of annular tracks are formed concentrically on a video floppy, and one field of video signals is recorded on each track. Here, in order to obtain a high-quality still image using one frame of video signal, each field of this video signal is recorded on two adjacent tracks. That is, in FIG. 14, if one field Fit of the video signal is now recorded on the track Tri on the video floppy 1, the other field Fi2 of the video signal is recorded on the track Tr2 adjacent to this track Tri. Ru. In this case, the recording start point of the video signal of each track on the video floppy 1 is on the same radius of the video floppy 1.

In order to record two fields of video signals on the video floppy 1 in this way, as shown in FIG. is used,
These head gaps G in the radial direction of the video floppy 1
i G2 are arranged side by side. Head gap G
1 is one field F of the video signal of one frame
The head gap G2 is used for recording and reproducing the other field Fi2 of the same video signal.

FIG. 16 is a timing chart showing the recording timing of these head gaps Gl and G2, and now, as shown in FIG. 16(a), at times T,,T,.

T 31 -----1 is the input point of the vertical synchronization signal of the input video signal, and the field Fil of this video signal is input between times T and T2, and the field Fil is input at time Tt + T3.
Field Fi2 is input in between, -・-+ 'r,,
It is assumed that field Fin is input between IT n h 1, and fields Fil and Fi2 are input to video floppy 1.
16, the video floppy 1 rotates once per field in synchronization with the vertical synchronization signal of this video signal, and the head gap G1 is as shown in FIG.
As shown in b), at time T,,T.

The field Fil is recorded in between, and then the head gap G2 records the next field Ft2 between times T2 and T3, as shown in FIG. This allows the first
As shown in FIG. 4, fields Fil and Fi2 are recorded on tracks Tr1 and Tr2, respectively, with their recording start points located on the same radius of the video floppy 1.

When playing still images by frames from such video floppy 1, 'r,', T! 'l T3'.

-・~ is the reproduction scanning time point of the recording start point of each track, the bed gaps Gl and G2 are respectively track 'l'
rl and Tr2 are repeatedly scanned for reproduction, and as shown in FIG. 17(a), the head gap G1 repeatedly reproduces the field Fil, and as shown in FIG. 17(b), the head gap G2 repeatedly reproduces the field Fi2. And time T
Field Fil from head gap G1 is selected between I'+'rz', and field Fi2 from head gap G2 is selected between the next time T2°l T3'', and in the same manner, the head gap is changed for each field. G1
The field Fil from the head gap G2 and the field Fi2 from the head gap G2 are alternately selected and spliced. As a result, as shown in FIG. 17 (C1), a video signal in which the same frame is repeated is obtained, and a still image is reproduced in frames.

[Problem that the invention seeks to solve]

By the way, the following problems arise in the above-mentioned conventional techniques.

First of all, in an in-line head like the one shown in FIG. 15, the gap between the two heads is extremely close (in the case of an electronic still camera, the track pitch is 100 μm and the track width is 60 μm; The distance between the two head gaps is 40 μm), and during reproduction, crosstalk occurs between the respective head cores having a head gap. That is, in FIG. 15, the magnetic flux of the first herad core having the head gap G1 jumps into the second herad core having the head gap G2, and a crosstalk component is mixed into the reproduced signal from the second herad core,
Similarly, the magnetic flux of the second bed core jumps into the first head core, and a crosstalk component is mixed into the reproduction signal of the first bed core.

Also, 1st. The magnetic coupling of the coils included in the second core also causes crosstalk. A head that prevents such losstalk is disclosed in Japanese Patent Application Laid-Open No. 60-45912, but this head has a complicated and special structure, and therefore requires special manufacturing technology, which is different from the conventional one. The cost is significantly higher than that of an in-line head, and even with a special structure, crosstalk cannot be completely eliminated.

Secondly, the in-line head has a wide contact area with the video floppy, and it is very difficult to make the two heads come into even and good contact with the video floppy. Strict dimensional accuracy is required, and complex installation requires adjustment mechanisms. Moreover, the dimensional accuracy of the in-line head has been tightened,
Even if the installation is adjusted, poor contact between the head gap and the video floppy will occur if used for a long time.

Third, differences in characteristics tend to occur between the two head gaps, and the reproduced video signal is affected by these differences in characteristics.

By the way, in a video floppy device, in addition to still image playback using frames, it is also possible to perform still image playback by field recording and repeated field playback, and still image playback by frame recording and repeated playback of the same field. In both cases, only one head gap of the in-line head is used during reproduction. Therefore, in the latter case, in FIG. 15, suppose that the head gap G1 records one field of the video signal on the track Tri, and the bed gap G2 records the next one field on the adjacent track Tr2. In the case of field-based still image reproduction, the head gap G1 may repeatedly reproduce one field of the video signal from the track Tri, but may also repeatedly reproduce one field of the video signal from the track Tr2. This also applies to the head gap G2. To enable such still image playback, the head gap Gl
, G2 are set to the same azimuth angle, and the magnetization direction of each track is the same.

In this way, in order to make the magnetization direction of each track on a video floppy the same, a head with a single head gap is used, and the track is advanced field by field, so that one field per revolution of the video floppy is used. This can also be achieved by recording a video signal, and by alternately reproducing two adjacent tracks of a video floppy on which video signals are recorded, still images can also be played back in frames. Moreover, according to this method, all of the first to third problems mentioned above are solved. however,
It takes time for the head to advance the track, and for this reason,
There is a problem in that signal dropouts occur between tracks.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-performance and highly reliable video signal recording and reproducing apparatus that solves these problems, has a simple head structure, and can reproduce still images with good frames.

[Means for solving problems]

In order to achieve the above object, the present invention extracts two desired fields of an input video signal, and divides one field and the other field into two fields before and after a track feed period of a head having a single head gap. supply to the head,
During playback, one of the two adjacent tracks is scanned for playback by the head, and then the other track is scanned for playback by advancing the track. In this way, the fields from each track played are alternately and Make it output repeatedly.

[Effect]

One of the two desired fields is 1 on the rotating recording medium.
The track is completely recorded without any omissions, and the other field is completely recorded over the entire track adjacent to this track without any omissions.

During reproduction, two adjacent tracks on the rotating recording medium are completely scanned for reproduction before and after the track feed period of the head, and fields are reproduced from each track without any omissions. By alternately and repeatedly outputting these fields, a video signal that can reproduce still images in frames can be obtained.

〔Example〕

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

FIG. 1(al) is a block diagram showing a recording system of an embodiment of a video signal recording/reproducing apparatus according to the present invention, and FIG. 1(b) is a block diagram showing a playback system as well. In,
1 is a video floppy, 2 is a head, 3 is an input terminal, 4 is an A/D converter, 5 is a field memory, 6 is a changeover switch, 7 is a D/A converter, 8 is a recording circuit, 9 is an output terminal,
10 is a head feeding mechanism, and in FIG. This is the output terminal. Fig. 1 (a), (b)
Common parts are given the same symbols.

First, the recording system shown in FIG. 1(a) will be explained.

The video signal input from the input terminal 3 is converted into a digital video signal by the A/D converter 4, and is supplied to the field memory 5 and the contact A side of the changeover switch 6. The changeover switch 6 is normally closed to the contact A side, and this changeover switch 6
The digital video signal from is converted into an analog signal by a D/A converter 7 and then supplied to an output terminal 9 and a recording circuit 8. The signal is supplied from the output terminal 9 to a monitor, a viewfinder, etc. (not shown), and the image is displayed on these.

Further, the recording circuit 8 is provided with a gate, which is normally closed and no video signal is supplied to the head 2.

Now, when it is determined that the desired image to be reproduced as a still image is displayed by monitoring the screen of the monitor, viewfinder, etc., when the user performs a predetermined operation, A
A gate provided in a recording circuit 8 having a GC circuit, a non-linear emphasis circuit, an FM modulator, etc. is connected to an input terminal 3.
It opens for one field period in synchronization with the video signal input to the recording circuit 8, and the video signal for this period is processed by the recording circuit 8 and supplied to the head 2. The video floppy 1 rotates at a rate of once per field, with the phase pulse obtained every rotation being synchronized with the vertical synchronization signal of the video signal from the input terminal 3, and is supplied to the head 2. One field of video signals is recorded over one annular track on a video floppy 1.

When the head 2 finishes recording and the gate of the recording circuit 8 closes, the field memory 5 simultaneously starts writing the next field of the digital video signal, and the field memory 5 starts writing the next field of the digital video signal.
One field of digital video signal is written.

On the other hand, the head 2 is a head having a single head gap G, as shown in FIG.
At the start of writing, the head feed mechanism 10 feeds the video floppy 1 in the radial direction by one track pitch. When the track feeding of the head 2 is completed, the switching signal 6 is switched to the contact B side in synchronization with the vertical synchronization signal of the video signal from the input terminal 3, and the field memory 5 starts reading out the digital video signal. , the gate of the recording circuit 8 is opened and the data from the D/A converter 7 to the recording circuit 8 is opened.
is supplied to the head 2 via. When one field of digital video signals is read out from the field memory 5, the readout operation is completed, the switch 6 is switched to the contact A side, and the gate of the recording circuit 8 is closed. As a result, the next field of the video signal is also transferred to the video floppy 1.
recorded over one entire annular track on the top.

Through the above operations, as shown in FIG. 14, on the video floppy 1, when one field Fit of the video signal of one frame is recorded on the track Tri, the next field Fi2 is recorded on the next adjacent field Fi2. The data is recorded on track Tr2, and the recording start points (recording positions of vertical synchronization signals) of these tracks Tri and Tr2 are located on the same radius of video floppy 1.

FIG. 3 is a timing chart showing the above recording operation. (a) of the same figure shows the video signal input to the input terminal 3, and shows the video signal inputted to the input terminal 3 at time T + + T z * T 31 '-"-
is the input point of the vertical synchronization signal of this video signal. Further, ('b) of the same figure shows the operation of the head 2, and (C1) of the same figure shows the operation of the field memory 5, respectively.

Now, the field Fil of this video signal is input between times T+ and T, the field Fi2 is input between times T2 and Tz, and...
,,T. .

Assuming that a field Fin is inserted in between, and that the user performs a recording operation for still image playback immediately before time T+, as shown in FIG. The intervening field Fi1 is supplied and recorded on the video floppy 1. At time T2 when this recording ends, the field memory 5 starts writing the next field Fi2, as shown in FIG. 3(C). When this writing to the field memory 5 is completed (time T
3) As shown in FIG. 3(b), the head 2 is track-fed by one track pitch in the radial direction of the video floppy 1, and the vertical synchronizing signal is input to the input terminal 3 at time T7 immediately after this track feeding is completed. Then, as shown in FIG. 3(C), reading of field Fi2 of the field memory 5 is started, and as shown in FIG. 3(bl), this read field Fl is supplied to the head 2. and recorded on video floppy 1.

In the manner described above, one frame of video signal can be recorded on a video floppy field one field at a time and with the vertical synchronization signal recording positions aligned.

In FIG. 1(a), the field memory 5 starts reading the field Fi2 after the head 2 moves the track, but the repeated reading may start at the same time as the writing of the field Fi2 ends. In this case as well, it goes without saying that the gate of the recording circuit 8 should be opened at the timing described above after the head 2 has moved the track.

Furthermore, when the changeover switch 6 is closed to the contact A side, the video signal input to the input terminal 3 is supplied to the monitor etc. from the output terminal 9 via the changeover switch 6, so that the field memory 5 Immediately after the writing of Fi2 is completed, reading from the field memory 5 is started, and at the same time, the changeover switch 6 is switched to the contact B side, so that the video signal of field Fi2 is repeatedly read out from the field memory 5 without interruption. is supplied to the monitor, allowing continuous monitoring from moving images to still images without any interruption, and therefore without skewing and making it difficult to view.

Next, the reproduction system shown in FIG. 1 (bl) will be explained using the timing charts of FIGS. 2 and 4. In FIG. b
) shows the operation of the field memory 13, and (C
) represents the video signal obtained at the output terminal 16.

Also, T I'+ 'r,', 'r, °l'---
---. represents the reproduction time of the vertical synchronization signal.

Prior to still image playback, first, as shown in FIG. 2, the head 2 is placed on the video floppy L so that the head gap G is on the track Trl on which the field Fil is recorded, and the head 2 is placed so that the video floppy 1 is By rotating the field once per field, the field Fil is repeatedly reproduced from the track Trl. This reproduction signal (fourth
Figure (a)) is processed by the reproduction circuit 11, and is processed by the A/D converter 4.
After being converted into a digital video signal, selector switch 1
4 and the field memory 13.

This digital video signal is written into the field memory 13 for one field between times Tl' and Tz° at the timing shown in FIG. 4Cb).

At this time, the changeover switch 14 may be located on the contact A side or the contact B side. Note that the regenerative circuit 11 is a regenerative amplifier, F
It has an M demodulator, a nonlinear de-emphasis circuit, etc.

When the writing of the frame Fil in the field memory 13 is completed, the head 2 is moved by the head feeding mechanism 10.
The track is fed so that the head gap G is above the adjacent track TrZ (Fig. 2), and this track Tr2
Playback of field Fi2 is started from. As shown in FIG. 4(a), this field Fi2 is repeatedly reproduced, converted into a digital video signal by the A/D converter 12, and then supplied to the contact A of the changeover switch 14 and the field memory 13. Ru.

At this time, the field memory 13 starts reading out the digital video signal of the field FIL in synchronization with the reproduction signal from the head 2. That is, after the track feed of the head 2 is completed, as shown in FIG. This reading is repeated, and the read digital video signal is supplied to the contact B side of the changeover switch 14.For this purpose, the field Fi2 that is supplied to the contact A side of the changeover switch 14 is repeated. The phase of the vertical synchronization signal matches that of the digital video signal of the repeating field FIL supplied to the contact B side.

The changeover switch 14 is switched from contact A to contact B and vice versa within the vertical retrace period of the digital video signal supplied to the contacts A and B sides. As a result, a digital video signal in which fields Fi1 and Fi2 are alternately arranged is obtained from the changeover switch 14. This digital video signal is converted into an analog signal by a D/A converter 15, and is supplied from an output terminal 16 to a monitor (not shown) or the like.

The video signal obtained at this output terminal 16 is shown in FIG. 4(C).
As shown in FIG. 2, fields Fil and Fi2 are alternately repeated, thereby performing frame-based still image reproduction.

Note that as long as the video floppy disk 1 rotates in the same phase while the head 2 is moving the track, the field memory 13 will be able to read the field Fi immediately after the writing of the field Fi is completed.
It may start reading l repeatedly. in this case,
Until time T7' in FIG. 4, the changeover switch 14 is at contact A;
It may be closed in either direction B. Needless to say, if the contact is closed to the B side, still image reproduction will be performed, although it is based on the field.

As described above, in this embodiment, it is possible to reproduce still images in frames using a head having a single head gap. In this way, since a head with a single head gap is used, crosstalk does not occur, and problems caused by differences in head characteristics and the contact state between the head and the video floppy do not occur.

According to this embodiment, it is also possible to reproduce still images by field. In this case, there are two types of recording operations of the recording system shown in FIG. 1(a). One is to close the changeover switch 6 to the contact A side, extract one field from the video signal from the input terminal 3 at the gate of the recording circuit 8, and record it using the head 2. Close the selector switch 6 to the contact B side, and the video signal 1 from the input terminal 3
The field is written into the field memory 5, and then read out repeatedly, and the one field is extracted by the gate of the recording circuit 8 and supplied to the head 2. In particular, the latter method makes it possible to reconfirm the contents of the field to be recorded by supplying the video signal obtained by repeatedly reading out the field memory 5 to a monitor, viewfinder, etc. via the output terminal 9. A decision can be made as to whether or not to record. Therefore, recording of unnecessary fields can be avoided and the video floppy can be used more effectively. Furthermore, until recording is started on the video floppy 1, the video floppy 1 can be stopped or the head 2 can be moved away from the video floppy 1, which can extend the life of the video floppy 1. This makes it possible to reduce wear on the head and extend its life.

There are two types of playback operations for the playback system shown in FIG. Signal regeneration circuit 11.
'A/D converter 12. Changeover switch 14. The other one is to close the changeover switch 14 to the contact B side and temporarily transfer one field of the reproduced signal from the head 2 to the field memory 13. After that, this is repeatedly read out and outputted from the output terminal 16.

Particularly in the latter case, once one field has been written to the field memory 13, it is no longer necessary to reproduce the signal from the video floppy 1. For this purpose, the rotation of the video floppy 1 may be stopped, or the head 2 may be separated from the video floppy 1. Thereby, the life of the video floppy 1 and the head 2 can be extended.

FIG. 5 is a block diagram showing another embodiment of the video signal recording and reproducing apparatus according to the present invention, in which reference numerals 17 and 18 are changeover switches, and parts corresponding to those in FIG. 1 are given the same reference numerals and are duplicated. The explanation will be omitted.

In the embodiment shown in Fig. 1, an A/D converter, a field memory, a changeover switch, and a D/A converter are provided in each of the recording system and the reproduction system, but these are mostly used in the recording system and the reproduction system. They have the same functions, and for this reason, in the embodiment shown in FIG. 5, these are shared by the recording system and the reproduction system.

That is, in FIG. 5, a changeover switch 17 is provided upstream of the A/D converter 4 to switch between the input terminal 3 and the reproduction circuit 11, and a changeover switch 18 is installed upstream of the head 2. Recording circuit 8 and reproduction circuit 11
I am trying to switch between.

The changeover switches 17 and 18 are closed to the R side during recording, and closed to the P side during playback. When the selector switches 17 and 18 are closed to the R side, the video signal input to the input terminal 3 is
A recording system similar to that in a) is formed, and the changeover switch 17.1
8 closes to the P side, the first
A reproduction system similar to that shown in Figure (b) is configured. Therefore, in this embodiment as well, the same operation as in the embodiment shown in FIG. 1 can be performed and the same effect can be obtained.
Furthermore, the following unique effects can also be obtained.

This means that it is possible to determine at the time of recording whether it is better to reproduce still images by fields or by frames. In order to play back high-quality still images, it is desirable to play back still images in frames, but in the case of video signals that represent a subject with rapid movement, the information content differs between two fields within the same frame, which can cause When playing still images,
Image blur appears on the display screen, making it difficult to view. In this case, still image playback using fields is preferable. In the embodiment shown in FIG. 1, in order to avoid still image playback that causes such screen blur, when screen blur occurs, the selector switch 14 in FIG.
is fixed to the contact A side or the contact B side, and the playback signal from the head 2 or the read signal from the field memory 13 is output from the output terminal 16, and still image playback by field can be performed. One frame of video signal is recorded in the field, and since the information content of the two fields is almost the same and it is sufficient to use only one of them, one track is occupied by unnecessary fields. video floppy 1
will be wasted.

In the embodiment shown in FIG. 5, such waste can be avoided and only one field can be recorded on the video floppy 1 when it is necessary to reproduce a still image using fields. This point will be explained below.

First, the changeover switches 1, 7, and 18 are closed to the contact R side, and the changeover switch 6 is closed to the contact A side. And input terminal 3
When a video signal is input from the floppy disk and a recording operation for still image playback is performed, one field FIL of the video signal is recorded on the video floppy 1 by the head 2, and the next field is recorded as shown in FIG. 1(a). Field Fi2 is written into the field memory 5.

Next, the head 2 is left in the same position and the changeover switches 17 and 18 are switched to the contact P side.

As a result, the field Fi recorded on the video floppy 1 is repeatedly reproduced by the head 2, and in synchronization with this, the field Fi2 is repeatedly read out from the field memory 5. The repetitive video signal of the field F1 reproduced by the head 2 is supplied to the contact A side of the changeover switch 6, and the repetitive video signal of the field Ft2 read from the field memory 5 is supplied to the contact B side of the changeover switch 6. The changeover switch 6 is alternately switched to contacts A and H during the vertical retrace period of these video signals, thereby obtaining a video signal in which fields Fil and Fi2 are alternately repeated. This video signal is supplied to a monitor or the like from an output terminal 9 via a D/A converter 7.

As a result, still image playback is performed using frames. When looking at the displayed still screen, if the image quality is good, still image playback using frames is preferable. 17.18 to contact R
At the same time, the head 2 is moved one track pitch by the head feeding mechanism 10, and the field Fi2 is read out from the field memory 5 and recorded on the video floppy 1 by the head 2. If the displayed still screen is blurred, it is preferable to reproduce the still image by field, so at this time, the field Fi2 written in the field memory 5 is not recorded on the video floppy l.

In addition, if a still image using a field is preferred, the changeover switch 6 is switched between the contact A side and the contact B side while the changeover switches 17 and 18 are closed to the contact P side, and the head 2
Compare the still image of the field Fi reproduced from the field memory 5 with the still image of the field Fi2 read from the field memory 5, and if the former has better image quality, leave the field Fi recorded on the video floppy 1, and compare the still image of the field Fi2 read from the field memory 5. If the image quality is better, the head 2 is left in the same position, field Fi2 is read from the field memory 5, and field F of the video floppy 1 is read out.
It is also possible to record a field Fi2 instead of this field on the track where il is recorded. As a result, of the two fields, the field that provides a still image with better image quality can be recorded. In the case of still image reproduction using such fields, the video floppy 1 may be stopped once the reproduced field is written to the field memory 5 during reproduction, so there is no risk of damage to the video floppy 1 or wear of the head 2. can be reduced.

In the embodiments shown in FIGS. 1 and 5, the preceding field of one frame was first recorded on the video floppy, and the following field was written into the field memory, but conversely, the preceding field is It is also possible to write to memory and record subsequent fields directly to the video floppy, with only a slight timing shift. The same applies to playback.

FIG. 6 is a block diagram showing still another embodiment of the video signal recording and reproducing apparatus according to the present invention, in which 19 is a frame memory, and parts corresponding to those in FIG. 5 are given the same reference numerals.

This embodiment corresponds to the case where the field memory 5 and changeover switch 6 in FIG. 5 are replaced with a frame memory 19.

In FIG. 6, during recording, the changeover switches 17 and 18 are closed to the contact R side, and the video signal input to the input terminal 3 is transferred to the changeover switch 17. The signal is supplied to the frame memory 19 via the A/D converter 4.

When the user performs a predetermined operation, the field Fil and the following field Fi2 of this video signal are written into the frame memory 19. Thereafter, the field Fil is read out from this frame memory 19, and the field Fil is read out from the D/A converter 7. Recording circuit 8. The signal is supplied to the head 2 via the changeover switch 18 and recorded on the video floppy 1. Next, the head 2 is moved to 1 by the head feeding mechanism 10.
Only the track pitch is sent, and when this track sending is completed, the field Fi2 is transferred from the frame memory 19.
is read out and recorded on video floppy 1.

In this case, the rotational phase of the video floppy 1 and the readout phase of the frame memory 19 are synchronized, and as explained in FIG.
so that they are aligned on the same radius.

During playback, the changeover switches 17 and 18 are switched to the contact P side. The head 2 first reproduces the field Fil from the video floppy 1, and this field Ftl is transferred to the selector switch 18. Regeneration circuit 11° changeover switch 17. A/
The signal is supplied to the frame memory 19 via the D converter 4 and written into the frame memory 19. Next, the head 2 is moved by the head transport mechanism 10 to the track where the field Ft2 is recorded, and this field Fi2 is reproduced. This field Fi2 is also written to the frame memory 19 in the same manner. When writing is completed, fields Fi1. Fi2 is read out alternately and supplied to a monitor (not shown) from the output terminal 9 via the D/A converter 7. As a result, still image reproduction is performed in frames.

Also in this embodiment, during recording, the frame memory 19 is read out and the read video signal is sent to the output terminal 9.
Field Fit can be supplied to the monitor to select whether to play back still images using frames or fields, or when playing still images using fields.

It is possible to select which of the Fi2 files to record on the video floppy 1. It is also possible to check whether the contents of each field written in the frame memory 19 are desired.

Furthermore, during recording, the writing of video signals to the frame memory 19 and the driving of the video floppy 1 are independent of each other, and it is only necessary to rotate the video floppy 1 when recording a field. Damage to the head 2 and wear on the head 2 can be reduced, and since the necessary image can be taken into the frame memory 19 regardless of the state of the video floppy 1, it is possible to reliably reproduce the still image of the necessary image. can.

Furthermore, during playback, after writing two fields to the frame memory 19, playback from the video floppy 1 is no longer necessary, and therefore the video floppy can be stopped, preventing damage to the video floppy 1 and damage to the head 2. Can reduce wear.

Furthermore, when playing still images using frames, after two fields have been written to the frame memory 19 during recording, by immediately reading them out and supplying them to the monitor from the output terminal 9, it is possible to play back the still images during recording. However, since reading from the frame memory 19 is possible even while the head 2 is moving tracks by the head feeding mechanism 10, there is no interruption in still image playback and no skew occurs on the monitor screen and makes it difficult to see. do not have. This also applies during playback.

FIG. 7(a) is a block diagram showing a recording system of still another embodiment of the video signal recording and reproducing apparatus according to the present invention, and FIG. 7(b)
are the same (block diagram showing a reproduction system).

In addition, in FIG. 7(a), 20 is an input terminal, 21 is a Y/C (luminance signal/chroma signal) separation circuit, 22° 23
is an AGC circuit, 24 is a duder, 25 is an input terminal, 26
is a matrix circuit, 27 is a switching circuit, 28.29 is a digital processing circuit, 30.31 is a non-linear emphasis circuit, 32.33 is an FM modulation circuit, 34 is an addition circuit, 3
5 is a recording amplifier, and in FIG. 7(b),
36 is a regenerative amplifier, 37 is an HPF (bypass filter), 38 is an LPF (low pass filter), 39.40
is an FM demodulation circuit, 41.42 is a de-emphasis circuit,
43 and 44 are digital processing circuits, 45 is an encoder,
46 is an adder circuit, 47 is an output terminal, 48 is a matrix circuit, and 49 is an output terminal.

First, the recording system of FIG. 7 (al) will be explained.

An NTSC color video signal (hereinafter referred to as NTSC signal) is input to the input terminal 20, and R and G signals from a video camera or the like are input to the input terminal 25.

A primary color signal of B and a synchronization signal S are input.

When an NTSC signal is input to the input terminal 20, the switching circuit 27 is closed to the contact M side, and this NTSC signal is separated by the Y/C separation circuit 21 into a luminance signal (hereinafter referred to as Y signal) and a chroma signal ( (hereinafter referred to as C signal),
After being processed by the AGC circuit 22, the Y signal is sent to the switching circuit 2.
7 to a digital processing circuit 28. After being processed by the AGC circuit 23, the C signal is processed by the AGC circuit 22.
The signal is supplied to the decoder 24 along with the Y signal outputted from the decoder 24 to generate an RY signal and a BY signal.

These R-Y signal and B-Y signal are supplied to a digital processing circuit 29 via a switching circuit 27.

When the R, G, and B signals and the synchronizing signal Sv are input to the input terminal 25, the switching circuit 27 is closed to the N side, and these signals are supplied to the matrix circuit 26 to switch between the Y signal and the R-
A Y signal and a BY signal are generated. The Y signal is supplied to the digital processing circuit 28 via the switching circuit 27, and the R-
The Y signal and the BY signal are supplied to a digital processing circuit 28 via a switching circuit 27.

Here, the digital processing circuit 28 is a part constituted by the A/D converter 4, field memory 5 degree changeover switch 6, and D/A converter 7 in FIG. D converter 4. It has the same configuration as the part constituted by the frame memory 19 and the D/A converter 7, and has the same configuration as the part configured by the frame memory 19 and the D/A converter 7.
Alternatively, the same operation as explained in FIG. 6 is performed. The digital processing circuit 29 also has the same components as the digital processing circuit 28, but is further provided with a changeover switch at the front stage of this component, which allows the R-Y signal, the B
A line-sequential color signal (R-Y/B-Y signal) of the -Y signal is generated, and the same processing as explained in FIG. 1 (al or FIG. 6) is performed on this line-sequential color signal.

FIG. 8 specifically shows an example of this digital processing circuit 29, in which 50 is a changeover switch, 51 is an A/D
Converter 52 is a frame memory, 53 is a D/A converter. In the figure, the changeover switch 50 is the R-Y signal,
A line sequential signal is formed from the B-Y signal, and A/
D converter 51. Frame memory 52. D/A converter 53
are the A/D converters 4. and 4. of FIG. 6, respectively. Frame memory 19.
Corresponds to the D/Ai converter 7. By replacing the frame memory 52 with a field memory and a changeover switch, it is possible to correspond to that shown in FIG. 1(a).

One field of the Y signal outputted from the digital processing circuit 28 and one field of line sequential color difference signals outputted from the digital processing circuit 29 are processed by the nonlinear emphasis circuits 30 and 31, respectively, and then sent to the FM modulator 32.
The signals are FM-modulated and added in an adder circuit 34. The output signal of the adder circuit 34 is amplified by the recording amplifier 35 and sent to the head 2.
and recorded on one track on a video floppy (not shown).

When the recording of this one field is completed, the head 2 moves by one track pitch, and then the Y of the next field.
Line-sequential color signals are output from digital processing circuits 28 and 29 and similarly recorded on a video floppy.

Here, the AGC circuits 22 and 23 are provided before the digital processing circuits 28 and 29 in order to effectively use the dynamic range of the A/D converter in the digital processing circuits 28 and 29. Furthermore, since the non-linear emphasis circuits 30 and 31 expand the dynamic range, they are provided after the digital processing circuits 28 and 29. Furthermore, the digital processing circuits 28 and 29 are connected to the FM modulation circuit 32.
If installed after ゜33, digital processing circuit 28゜2
Since the sampling frequency of the A/D converter in 9 must be very high, the digital processing circuit 28
．． 29 is provided before the FM modulation circuits 32 and 33.

Note that when the input signal is only one of the NTSC signal and the primary color signal, the switching circuit 27 and the matrix circuit 26 or the Y/C separation circuit 21 and the AGC circuit 23
．． Decoder 24 is not required.

Next, the reproduction system shown in FIG. 7(b) will be explained.

One field is reproduced from a video floppy (not shown) by the head 2, amplified by a reproduction amplifier 36, and then separated into an FM-modulated Y signal and a line-sequential color difference signal by an HPF 37 and an LPF 38. The Y signal is demodulated by an FM demodulation circuit 39, processed by a de-emphasis circuit 41, and supplied to a digital processing circuit 43. The line-sequential color difference signal is also demodulated by the FM demodulation circuit 40, processed by the de-emphasis circuit 42, and supplied to the digital processing circuit 44.

The digital processing circuit 43 is connected to the A/
D converter 12. Field memory 13. Changeover switch 1
4 and the D/A converter 15, or the A/D converter 4 in FIG. It has a configuration similar to that of the frame memory 19 and the D/A converter 7, and also includes the digital processing circuit 4.
4 also has the same components as the digital processing circuit 43, but is further provided with sequential/simultaneous conversion means at the subsequent stage of this component, thereby converting the line-sequential color difference signal into continuous RY and B-Y signals. is generated.

FIG. 9 specifically shows an example of this digital processing circuit 44, in which 54 is an A/D converter, 55 is a frame memory, 56 is a D/A converter, and 57 is an IH delay line (however, IH is one horizontal scanning period), and 58 is a switching circuit.

In the figure, an A/D converter 54. frame memory 55
．． The D/A converters 56 are respectively A/D converters 4. It corresponds to the frame memory 19 and the D/A converter 7. Also,
IH delay line 57. The switching circuit 58 is a sequential/simultaneous conversion means, and in the switching circuit 58, the line sequential color difference signal from the D/A converter 56 and the line sequential color difference signal delayed by the IH delay line are alternately selected for each IH. By doing this, a continuous RY signal is obtained, and by changing the selected phases by 180°, a continuous BY signal is obtained. By replacing this frame memory 55 with a field memory and a changeover switch, it can be made to correspond to FIG. 1 (bl).

After filling this field into memory in the digital processing circuits 43, 44, the head 2 is advanced one track pitch to reproduce the next field. The Y signal and line-sequential color difference signal of this field are similarly supplied to the digital processing circuit, respectively.

The digital processing circuit 43 processes the Y signal as shown in FIG.
) or perform the same operation as the corresponding part in Figure 6,
Outputs a Y signal in which two fields alternate.

The digital processing circuit 44 also performs the same operation as the corresponding part in FIG. 1(b) or FIG. Generates and outputs a Y signal and a BY signal.

These R-Y signals and B-Y signals are processed by the digital processing circuit 4.
3 is supplied to the encoder 45 together with the Y signal outputted by the C signal C, which is added to the Y signal in the adder circuit 46. As a result, an NTSC signal is obtained at the output terminal 47. Further, these R-Y signal and B-Y signal are supplied together with the Y signal to the matrix circuit 48, and the R, G, B signals and the synchronization signal S7 are obtained at the output terminal 49'.

Figure 10 shows the digital processing circuit 2 in Figure 7 (al).
9 is a block diagram showing another specific example of 59R,5
9B is A/D converter, 60R, 60B is memory, 61R
, 61B are D/A converters, and 62 is a changeover switch.

In FIG. 10, the memories 60R and 60B are frame memories or, as shown in FIG. 1(a), consist of a field memory 5 and a changeover switch 6.

Now, assuming that the memories 60R and 60B are frame memories, the R-Y signal is digitized by the A/D converter 59R and supplied to the memory 60R, and the B-Y signal is digitized by the A/D converter 59B. The signal is supplied to the memory 60B, and the memory 60'R extracts the RY signal every 1H, and the memory 60B extracts the B-Y signal every other IH and writes two fields at a time. After that, the memory 60R160B intermittently sends the RY signal every IH.

The B-Y signal is read out and the D/A converter 61R261B
After being converted into an analog signal by
line sequential color difference signals are generated.

When the memories 60R and 60B consist of a field memory and a changeover switch, they differ only in their operating points as explained in FIG. 1(a).

FIG. 11 shows the digital processing circuit 4 in FIG. 7(b).
4 is a block diagram showing another specific example of 63.64.
is A/D converter, 65R, 65B is memory, 66R, 6
6B is a D/A converter.

In FIG. 11, memories 65R and 65B are frame memories, and the line sequential color difference signals of R-Y/B-Y are
After being digitized by D converters 63 and 64, the memory 6
It is supplied to 5R and 65B.

The memory 65R stores R- every IH of the line sequential color difference signals.
The Y signal is extracted and read, and the memory 65B is also IH.
Extract and write the alternate B-Y signal. Memory 65R,
When the R-Y signal and B-Y signal for the line sequential color difference signal of one frame are written to 65B, 2
Reading is performed one time at a time, and a continuous RY signal is output from the memory 65R, and a continuous B-Y signal is output from the memory 65B.
Signals are obtained and converted into analog signals by D/A converters 66R and 66B, respectively.

The embodiment shown in FIG. 7 using the specific examples shown in FIGS. 10 and 11 has a higher A/D ratio than the embodiment shown in FIG. converter.

Although the number of D/A converters is doubled, the memories 65R and 65B in FIG. 11 also serve as sequential/simultaneous conversion means using frame memories, so the I in FIG.
The sequential/simultaneous conversion means consisting of the H delay line 57 and the switching circuit 58 is not required. Furthermore, since the memories 60R, 60B and memories 65R, 65B in FIGS. 10 and 11 are for storing color difference signals for every IH, the embodiment in FIG. 7 using FIGS. , 10 and 11, the capacity of the memory used is the same as the embodiment shown in FIG.

In FIG. 10, the R-Y signal and the B-Y signal extracted by the memories 60R and 60B are set to different IH intervals, but the IH signal is extracted on the same horizontal scanning line as the R-Y signal and the B-Y signal
It is also possible to extract every H. According to this, during playback, the R-Y signal extracted from the same horizontal scanning line and the B-
Color reproduction is possible with the Y signal, and false colors are almost eliminated from the contours of the reproduced image, improving image quality.

Figure 12 shows the digital processing circuit 2 in Figure 7 (al).
8 is a block diagram showing still another specific example of 67.
1 is a switching circuit, 68 is an A/D converter, and parts corresponding to those in FIG. 10 are given the same reference numerals.

In this specific example, the circuit 67 switches between the R-Y signal and the B-Y signal.
A line-sequential color difference signal is generated by switching, and this is digitized by an A/D converter 68 and supplied to memories 60R and 60B. The operation of other parts is the same as that in FIG. 10, and the number of A/D converters can be reduced compared to FIG.

FIG. 13 shows the digital processing circuit 4 in FIG. 7(b).
69 is a block diagram showing still another specific example of No. 4;
is an A/D converter, and parts corresponding to those in FIG. 11 are given the same reference numerals.

In this embodiment, during reproduction, the R-Y/B-Y line sequential color difference signal is digitized by an A/D converter 69 and then supplied to memories 65R and 65B. The operation of other parts is the same as that in FIG. 11, and the number of A/D converters can be reduced compared to FIG. 11.

Note that the digital processing circuit 29 in FIG.
With the configuration shown in the figure, the digital processing circuit 44 in FIG. 7(b)
If the configuration shown in FIG. 13 is used, the A/D converter, memory, and D/A converter in FIGS. 12 and 13 can be used together, and the A/D converter can be used as This means that only one memory, two D/A converters, and two D/A converters are required. In this case, in FIG.
If the order of the relationship between 1R and 61B and the switching circuit 62 is reversed, the number of D/A converters becomes one, which seems to be advantageous. Considering that the common parts can be used interchangeably, the D/A converter in Fig. 12 and the D/A converter in Fig. 13 cannot be used together, and in the end, the number of D/A converters becomes three. It would be rather disadvantageous.

Although the present invention has been described in detail above, the present invention is applicable not only to video floppies but also to other disk-shaped magnetic media, optical disks, and other disk-shaped recording media using other recording/reproducing methods.

〔Effect of the invention〕

As explained above, according to the present invention, by using a head with a single head gap, it is possible to reproduce still images in frames without being affected by the track feed time of the head, thereby preventing crosstalk between the head and the recording medium. The head structure is simplified, the cost is reduced, the performance is improved, and high-quality still images can be obtained.

[Brief explanation of drawings]

FIG. 1(a) is a block diagram showing the recording system of an embodiment of the video signal recording and reproducing apparatus according to the present invention, FIG. 1(b) is a block diagram showing the playback system, and FIG. 3 is a timing chart showing the operation of FIG. 1 (al), FIG. 4 is a timing chart showing the operation of FIG. 1('b), and FIGS. 7(5) is a block diagram showing a recording system of still another embodiment of the video signal recording and reproducing apparatus according to the present invention. 8(b) is a block diagram showing the reproduction system, FIG. 8 is a block diagram showing a specific example of the digital processing circuit for the color difference signal in FIG. 7(a), and FIG.
FIG. 10 is a block diagram showing another example of the digital processing circuit for line-sequential color difference signals in FIG. 7(a), and FIG. FIG. 12 is a block diagram illustrating another specific example of the digital processing circuit for line-sequential color difference signals in FIG. 7(b), and FIG. 1st
3 is a block diagram showing still another specific example of the digital processing circuit for line-sequential color difference signals in FIG.
Figure 4 is a track pattern diagram on a video floppy, No. 15
The figure is a plan view showing the structure of the head and its operation in a conventional video floppy device, FIG. 16 is a timing chart showing the recording operation of the conventional video floppy device, and FIG. 17 is a timing chart showing the playback operation. . 1--video floppy, 2--head, 3--
-1 Input terminal, 4---A/D converter, 5---Field memory, 6---Switch switch, 7---D/A converter , IQ-・・・・
-Head feed mechanism, 12-.-A/D converter, 13
------- Field memory, 14-...- selector switch, 15-- D/A converter, 16-...-
Output terminal, 1? , 18-------・Selector switch, Engineering 9・----Frame memory, G----
--Head gap, Trl. T r 2--Track, F i 1,
F i 2---field. Figure 1 (b) Figure 2 Figure 3 Figure 4 (C)
------------- Figure 13 Figure 14 Figure 15

Claims (1)

[Claims] 1. A head with a single head gap is connected to one of the video signals.
1 in the radial direction of a rotating recording medium that rotates with a field period.
In a video signal recording and reproducing device that feeds tracks in units of track pitch and forms tracks concentrically, one field and the other of two consecutive desired fields of an input video signal are sent before and after the track feeding period of the head. a first means for supplying the two adjacent tracks to the head; and a first means for reproducing and scanning one of two adjacent tracks on the rotary recording medium with the head, and then reproducing and scanning the other track by moving the head by track. and a second means for alternately and repeatedly outputting a field reproduced from the one track and a field reproduced from the other track to which the reproduction signal from the head is supplied by the second means. 3, the desired two fields are separately recorded field by field on each adjacent track of the rotating recording medium, and each adjacent track is reproduced to reproduce a still image in frames. A video signal recording and reproducing device characterized by: