JPH06178250A - Still video equipment - Google Patents

Abstract

PURPOSE:To improve the utilizing efficiency of a space of a recording medium by erasing all picture signals of a selected kind from picture signals recorded on plural track groups of the recording medium. CONSTITUTION:An erasure signal generating circuit 28 is connected to a terminal (e) of a changeover switch 29 selecting recording or erasure. When the erasure switch in an operation section 8 is operated, the terminal (e) of the changeover switch 29 is connected under the control by a system control circuit 10, the erasure signal generating circuit 28 is active and an erasure signal is outputted The erasure signal is amplified by a recording amplifier 27 and a picture signal recorded on a prescribed track of a magnetic disk 3 to be driven is erased by a magnetic head 6. Furthermore, as to the picture signal corresponding to one pattern, the erasure pattern is selected and erased, then ID data inputted to a system control circuit 10 are used and only the picture signal of the selected kind is erased and all of picture signals of the selected kind are erased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still video device for recording or reproducing image signals.

[0002]

2. Description of the Related Art In recent years, various recording / reproducing devices for recording and / or reproducing image, voice or other information have been developed and have become popular. Among these, the still video camera is a device capable of recording a captured image on a magnetic disk together with various information relating to the image and reproducing the captured image as a still image if necessary.

In this still video camera, a subject image is photoelectrically converted by a solid-state image pickup device to obtain a luminance signal and a color difference signal, these signals are FM-modulated and combined into a multiple image signal, and this image signal is rotated. The method of recording on the track of a magnetic disk is used. Further, ID data signals regarding field recording / frame recording, track number, shooting date, etc. are set to DPSK (Differential Pha).
se Sift Keying) and is recorded on a magnetic disk by superimposing it on the image signal by a frequency multiplexing method.

When reproducing the image signal recorded on the magnetic disk, the sampling pulse generated by the FM demodulated luminance signal and chrominance signal based on the vertical and horizontal synchronizing signals extracted from the luminance signal, respectively. According to the above, it is temporarily stored in a memory as digital data, read out according to a predetermined reference clock, converted into an analog signal, and then output to a video output terminal through an output circuit.

Among still video devices represented by such still video cameras, in a still video device having one magnetic head and a memory for storing image signals, when performing frame recording, two field images are respectively stored in the memory. Once, and each is recorded on one track. That is, two field images are recorded on two tracks. At the time of erasing, normally, the image signal for one screen, that is, the image signal for two fields is erased collectively, but since it is erased by one head, a track constituting another screen which should not be erased is mistakenly deleted. It may be erased.

There is also a still video device configured so that only one field of image signal, that is, one track can be erased from the viewpoint of not requiring high image quality and giving priority to the utilization efficiency of the magnetic disk.

By the way, in the case of the conventional recording system in which the luminance signal and the line-sequential chrominance signal are superposed and recorded on the same track, the frequency band of the luminosity signal and the frequency band of the chrominance signal should be overlapped. Therefore, the frequency band of the recorded luminance signal and the frequency band of the color difference signal are
Each is limited to a narrow range. Therefore, it is not possible to record a high-definition image, that is, an image based on a wideband image signal.

Therefore, the present applicant has filed Japanese Patent Application No. 3-2681.
In No. 04, by dividing the image signal corresponding to one screen into a plurality of tracks and expanding the time axis for recording, the frequency band of the image signal to be recorded is substantially expanded, and a high-definition image A still video device capable of recording is disclosed.

In such a still video device, field recording or frame recording is performed to record an image signal on a plurality of tracks, and thereafter, as described above, 1
Alternatively, when the image signal corresponding to two fields is erased, some of the tracks that should be erased may remain without being erased. In addition, a track that should not be erased may be erased by mistake.

In the case of performing field recording or frame recording in a still video device capable of recording a luminance signal and two types of color difference signals forming an image signal corresponding to one screen on a plurality of tracks different from each other. , For example, the luminance signals belonging to the first field are recorded on the second to the outermost tracks of the magnetic disk,
There is a recording pattern in which the luminance signals belonging to the second field are recorded on the following fourth tracks and the color difference signals corresponding to the respective luminance signals are recorded on the following eighth tracks. In this case, Requires a total of eight tracks to record one image.

In such a case, similarly to the above, from the viewpoint that high image quality is unnecessary and the utilization efficiency of the magnetic disk is prioritized, it is desired to erase only the image signal for one field after recording the image on the magnetic disk once. There is a request. Also, from the viewpoint of prioritizing the utilization efficiency of the magnetic disk, that is, in order to increase the number of images that can be recorded on the magnetic disk, recording the luminance signal and the color difference signal on different tracks is used, and only the color difference signal is used. There is a demand for erasing the image and leaving the color image once recorded on the magnetic disk as a monochrome image.

However, since the conventional still video device does not have a function of erasing only a desired track, that is, an image signal of a desired type, the above demand cannot be satisfied, and a manual operation, for example, for one field. When erasing the image signal or the color difference signal corresponding to the above, some of the four tracks corresponding to one field or the four tracks corresponding to the color difference signal remain without being erased. There is.

In addition, a track that should not be erased may be erased by mistake. For example, when erasing an image signal belonging to one field, a part of the image signal belonging to the other field or the image signal of another screen may be erased, and when erasing the color difference signal,
The luminance signal or part of the image signal of another screen may be erased.

As described above, a track left in the same field as a track that is accidentally erased or a track that has been forgotten to be erased cannot form a normal image, and these tracks become useless space. Since such tracks are mixed in the magnetic disk, there is a problem that the utilization efficiency of the magnetic disk is poor.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a still video apparatus in which the utilization efficiency of a magnetic disk is improved by erasing all the image signals recorded in a predetermined track group according to the purpose. It is in.

[0016]

These objects are achieved by the present invention described in (1) to (8) below.

(1) A function of recording an image signal corresponding to one screen composed of 1 or 2 fields on a plurality of tracks of a recording medium, and a function of erasing the image signal recorded on the track. A still video device having a recording system having a plurality of tracks, wherein the recording system sets a predetermined track group among a plurality of tracks on which image signals corresponding to one screen are recorded, and is recorded in this track group. The still video device is characterized in that it erases all the image signals recorded in the track group at this time.

(2) The still video device according to (1), wherein the image signal is composed of a luminance signal and a color difference signal.

(3) The still video device according to (2), wherein the luminance signal and the color difference signal are separately recorded on a plurality of tracks.

(4) The set track group is 1
The still video device according to any one of (1) to (3), which is a set of all tracks in which image signals for a screen are recorded.

(5) The still video according to any one of (1) to (3), wherein the set track group is a set of tracks in which image signals belonging to one field are recorded in frame recording. apparatus.

(6) The still video device according to (3), wherein the set track group is a set of tracks on which the color difference signals are recorded.

(7) The still video device according to any one of (1) to (3) above, which is capable of selecting the type of image signal to be erased.

(8) A still video device having a reproducing system for reproducing an image signal recorded on a recording medium by the recording system according to any one of (1) to (7),
The still video device, wherein the reproduction system is configured to synthesize and reproduce respective image signals recorded on a plurality of tracks.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The still video apparatus of the present invention will be described in detail below with reference to the preferred embodiments shown in the accompanying drawings. FIG. 1 is a block diagram showing a configuration example of a recording system of a still video device of the present invention. As shown in the figure, the still video device 1
Has a system control circuit 10 for controlling various functions of the still video device described later. The system control circuit 10 is usually composed of a microcomputer.

A magnetic disk drive mechanism 2 is installed in the still video device 1. The magnetic disk drive mechanism 2 has a spindle motor 5 that can rotate at high speed, and the rotation of the spindle motor 5 supplies a motor drive circuit 4 that supplies electric power to the spindle motor 5 to drive it.
It is controlled by the system control circuit 10 which controls the operation of the circuit 4.

The magnetic disk drive mechanism 2 is loaded with a magnetic disk 3 as a recording medium for recording a captured image, voice, various data relating to the image, etc., for example, in a state of being housed in a case. The magnetic disk 3 is formed by forming a magnetic layer on the surface of a circular sheet material.
(Circular) tracks are concentrically formed. Also,
The center of the magnetic disk 3 is structured so as to fit into the rotary shaft of the spindle motor 5, and during recording and reproduction, the magnetic disk 3 is driven by the spindle motor 5 at a constant speed (3600 rpm for NTSC system, PAL).
In the case of the method, it is rotated at 3000 rpm).

A predetermined number of FG pulses corresponding to the number of revolutions of the spindle motor 5 are output from the spindle motor 5, and one revolution of the magnetic disc 3 is set from the center of the magnetic disc 3 set on the rotation shaft of the spindle motor 5. 1 for each
One PG pulse is output. System control circuit 10
The spindle motor 5 based on these pulse signals.
Is controlled to rotate the magnetic disk 3 at a constant speed during recording and reproduction.

Further, the magnetic disk drive mechanism 2 includes
A magnetic head 6 is installed. This magnetic head 6
A stepping motor (not shown) moves the magnetic disk 3 in the radial direction continuously or intermittently (intermittently). That is, at the time of recording and reproducing, the stepping motor is driven to move the magnetic head 6 onto a predetermined track of the magnetic disk 3, and at the time of reproducing, the magnetic head 6 is placed at an appropriate position on the track and the maximum. The automatic tracking is performed to finely adjust the position of the magnetic head 6 so that the output of

The moving amount, moving speed and moving timing of the magnetic head 6 are controlled by the tracking drive circuit 7. The operation of the tracking drive circuit 7 is controlled by the system control circuit 10.

An operation unit 8 is connected to the system control circuit 10. The operation unit 8 has, for example, a selection switch for selecting one of field recording and frame recording, a head feed switch for moving the magnetic head 6 to a predetermined track of the magnetic disk 3, and recording an image signal on the magnetic disk 3. Rec switch for erasing, an erasing switch for erasing the image signal recorded on the magnetic disk 3, an erasing pattern selecting switch described later, a normal (standard image) / high-definition image selecting switch related to the recording processing method, etc. (Not shown) is installed as needed. Further, in the case of a still video device having both a recording system and a reproduction system, the operation unit 8 is also provided with a switch (not shown) for selecting either recording or reproduction.

A display unit (not shown) is connected to the system control circuit 10. The display section is related to, for example, field recording / frame recording, normal / high definition, track number, track recording / non-recording, shooting date / time, magnetic disk 3 loaded / unloaded, and power source. Information, information regarding flash light emission, and necessary information such as the current time are displayed by, for example, a liquid crystal or a light emitting element. Further, in the case of a still video device having both a recording system and a reproducing system, the display section also displays whether recording or reproducing.

When the still video device is a still video camera, it has an image pickup unit (not shown). This image pickup unit is composed of a lens system, an aperture stop, a mirror, an optical filter, a shutter, a solid-state image pickup device (CCD), etc. (not shown). When the shutter is opened, the image of the subject passes through the lens system, etc.
Image on top. The CCD may be either a black-and-white image or a color image, but in this embodiment, a color image will be described.

The CCD photoelectrically converts the formed image and outputs color signals (R, G, B). These color signals are amplified by an amplifier (not shown), and further, a luminance signal (Y) is obtained by a process / matrix circuit (not shown).
And two color difference signals (RY, BY).
Further, for the luminance signal, a horizontal and vertical synchronizing signal (S
_H ) is added and output as a luminance signal (Y + S _H ). In the case of a high-definition signal, the horizontal and vertical sync signals ( _SH ) are added to the two color difference signals (RY, BY), respectively. If the still video device does not have an image pickup unit, these signals are input from the external input terminal.

As shown in FIG. 1, the luminance signal (Y + S _H )
Passes through the low-pass filter 11A and is cut in a high frequency range that may become noise (aliasing noise due to sampling). From the luminance signal (Y + S _H ), the horizontal and vertical synchronization signals (S _H ) are separated and extracted by the synchronization signal separation circuit 13 and input to the clock generation circuit 14.
The clock generation circuit 14 generates a memory write clock signal that serves as a reference for writing to each memory, and the memory write clock signal is input to the memory control circuit 12 and the A / D converter 15A.

The luminance signal (Y) from which the horizontal and vertical synchronizing signals ( _SH ) have been separated is converted into a digital signal by the A / D converter 15A and temporarily stored in the Y memory 16A. The color difference signal (RY) (hereinafter referred to as the color difference signal (Pr)) is passed through the low-pass filter 11B and then A /
It is converted into a digital signal by the D converter 15B and temporarily stored in the Pr memory 16B. Similarly, the color-difference signal (BY) (hereinafter referred to as the color-difference signal (Pb)) passes through the low-pass filter 11C and then the A / D converter 16
Converted to digital signal by C, Pb memory 16C
Is temporarily stored in.

The memory control circuit 12 performs the following control on the basis of the memory write clock signal from the clock generation circuit 14 while timing the writing to each of the memories 16A to 16C. That is, based on the memory write clock signal from the clock generation circuit 14, A
As the / D converter 15A operates, the memory control circuit 12 operates the built-in write address counter to write the digital data of the luminance signal (Y) at a predetermined address of the Y memory 16A.

Further, the memory write clock signal from the clock generation circuit 14 is divided by the frequency divider 17 into 1/2 to activate the A / D converters 15B and 15C, and the memory control circuit 12 The built-in write address counter is activated to activate the Pr memory 16B.
And the digital data of the color difference signal (Pr) and the color difference signal (Pb) are written to predetermined addresses of the Pb memory 16C. The synchronization signal ( _SH ) included in the input signal such as the luminance signal is not sampled,
Therefore, it is not written to the memory.

From the synchronizing signal generating circuit 18, for example, NT
Horizontal and vertical synchronization signals (S) according to the SC system are output and input to the clock generation circuit 19. The clock generation circuit 19 generates a memory read clock signal which serves as a reference for reading from each memory, and the memory read clock signal is used as the memory control circuit 12 and the D / A.
Input to the converters 20A, 20B and 20C, respectively.

The memory control circuit 12 performs the following control on the basis of the memory read clock signal from the clock generation circuit 19 while timing the reading from each of the memories 16A to 16C. That is, based on the memory read clock signal from the clock generation circuit 19,
The memory control circuit 12 operates the read address counter incorporated therein to read the digital data of the luminance signal (Y) from a predetermined address of the Y memory 16A, and at the same time, the D / A converter 20A operates to read the data. The converted digital signal of the luminance signal (Y) is converted into an analog signal.

Further, based on the memory read clock signal from the clock generation circuit 19, the memory control circuit 12
Activates the built-in write address counter to read out the digital data of the color difference signal (Pr) and the color difference signal (Pb) from the predetermined addresses of the Pr memory 16B and the Pb memory 16C, respectively, and
The / A converters 20B and 20C operate to convert the read digital signal of each color difference signal into an analog signal.

In the memory control circuit 12, the mode switching between the memory writing control and the memory reading control is controlled by a mode switching command signal from the system control circuit 10.

The horizontal and vertical sync signals ( _SH ) from the sync signal separation circuit 13 and the horizontal and vertical sync signals (S) from the sync signal generation circuit 18 are also input to the system control circuit 10. Based on this, the rotation phase of the spindle motor 5 is controlled and used as a timing signal for other various operations.

In the case of recording such a high-definition image, the memory read clock signal from the clock generation circuit 19 has a smaller frequency than the memory write clock signal from the clock generation circuit 14, for example, 1/4. Has a frequency of. Therefore, the frequency of the read clock signal of the luminance signal is 1/4 of the frequency of the write clock signal, and the frequency of the read clock signal of both color difference signals is 1/2 of the frequency of the write clock signal. Thus, compared with the signal input to the recording system, the signal is expanded in the time axis and recorded.

The luminance signal (Y), the color difference signal (Pr) and the color difference signal (Pb), which are analog signals, are respectively
After the high frequency band is cut by the low pass filters 21A, 21B and 21C, the synchronizing signal adding circuits 22A, 22
Vertical and horizontal synchronizing signals (S) from the synchronizing signal generating circuit 18 are added by B and 22C.

Sync signal adding circuits 22A, 22B and 2
Terminals a, b and c of the changeover switch 23 are connected to 2C, respectively. The system control circuit 10 controls the switching of the terminals a, b, and c connected in the changeover switch 23, and sequentially outputs the luminance signal (Y + S), the color difference signal (Pr + S), and the color difference signal (Pb + S) to the recording processing circuit 24. input. The recording processing circuit 24 FM-modulates each input signal.

From the system control circuit 10, the field recording / frame recording, the field number in the case of frame recording, the normal recording / high-definition recording, the type of image signal to be recorded, that is, the luminance signal (Y + S) / Color-difference signal (Pr + S) / color-difference signal (Pb + S), a component of one screen (for example, in the case of 4-division, upper left / lower left / upper right / lower right of the screen), track number, shooting year ID data signal related to image information such as date is output,
The ID recording processing circuit 25 DPSK-modulates a carrier (carrier wave) generated based on the horizontal synchronizing signal (S) from the synchronizing signal generating circuit 18 based on the ID data signal to obtain a DPSK signal. The ID data will be described later.

The DPSK signal for this ID data is
The adder 26 synthesizes the FM-modulated image signal in the recording processing circuit 24. The adder 26 is connected to a terminal d of a changeover switch 29 for selecting recording / erasing. The changeover switch 29 is connected to the terminal d during recording and to the terminal e during erasing. The control for switching the terminals d and e connected in the changeover switch 29 is
This is performed by the system control circuit 10.

The image signal synthesized by the adder 26 passes through the changeover switch 29 to which the terminal d is connected, and then is amplified by the recording amplifier 27 controlled by the system control circuit 10 and then by the magnetic head 6. It is recorded on a predetermined track of the rotating magnetic disk 3.

In recording a high-definition image, the image signal corresponding to one screen is divided into a plurality of tracks and expanded on the time axis for recording. Therefore, data is stored in each of the memories 16A to 16C as follows. It will be divided.

FIG. 3 is a schematic diagram showing an example of a storage area pattern of image signals in the memories 16A to 16C. In the example shown in this figure, an image signal is recorded in a frame recording mode, and a luminance signal (Y) and a color difference signal (Pr) are recorded.
And a color difference signal (Pb) are recorded on a plurality of tracks. That is, one screen is composed of the first field and the second field, the luminance signal (Y) is divided into four for one screen, and the color difference signal (Pr) and the color difference signal (Pb) are each divided into two for one screen. Corresponding memories 16A-16
Stored in C. Note that FIG. 3 shows the arrangement of the storage area of the image signal in the memory and also corresponds to the configuration of the screen (still image) displayed on the display.

Regarding the luminance signal (Y), the screen has center lines E and F extending in the horizontal and vertical directions, respectively.
In the first field, the luminance signal Y ₁ corresponding to the upper left, the luminance signal Y ₂ corresponding to the upper right, the luminance signal Y ₃ corresponding to the lower left and the luminance signal Y ₄ corresponding to the lower right are respectively divided in the first field. , Y memory 16A in the first area, the second area, the third area, and the fourth area.

Regarding the color difference signal (Pr), the screen is divided into two by a center line G extending in the horizontal direction, and in the first field, the color difference signal Pr ₁ corresponding to the upper half and the color difference signal Pr corresponding to the lower half thereof. ₂ is stored in the fifth area and the sixth area of the Pr memory 16B, respectively.

Regarding the color difference signal (Pb), the screen is divided into two by a center line G extending in the horizontal direction, and in the first field, the color difference signal Pb ₁ corresponding to the upper half and the color difference signal Pb corresponding to the lower half thereof. ₂ is stored in the seventh area and the eighth area of the Pb memory 16C, respectively.

Similarly for the second field, the luminance signals Y ₅ , corresponding to the upper left, upper right, lower left and lower right of the screen,
Y ₆ , Y ₇ and Y ₈ are respectively the Y memory 16A.
Of the color difference signals Pr ₃ and Pr ₄ stored in the ninth, tenth, eleventh and twelfth areas of the screen of FIG.
The color difference signals Pb ₃ and Pb ₄ stored in the 13th and 14th areas of the
The 15th area and the 1st area of the Pb memory 16C, respectively.
It is stored in 6 areas.

Here, each divided screen of each signal in one screen (hereinafter, each divided screen of each signal is referred to as a constituent screen)
Configuration screen number No. Attach 1 to 16. In this case, the configuration screen number No. 1 to 16 are each Y
₁ , Y ₂ , Y ₃ , Y ₄ , Pr ₁ , Pr ₂ , Pb ₁ , Pb
₂ , Y ₅ , Y ₆ , Y ₇ , Y ₈ , Pr ₃ , Pr ₄ , Pb
It corresponds to ₃ and Pb ₄ .

FIG. 4 is a diagram showing an example of a track pattern formed on the magnetic disk 3. As shown in the figure, the above-mentioned image signals are recorded on 16 tracks which are continuously arranged in the radial direction of the magnetic disk 3. in this case,
The image signals belonging to the first field are recorded on eight consecutive tracks, and the image signals belonging to the second field are recorded on the other eight consecutive tracks. In the configuration shown, from the outer peripheral side of the magnetic disk 3 to the inner peripheral side,
Luminance signals Y ₁ , Y ₂ , Y ₃ , Y _{4 of} the first field, color difference signals Pr ₁ , Pr ₂ , color difference signals Pb ₁ , Pb ₂ , second
Field of the luminance signal _{Y 5, Y 6, Y 7} , Y 8, the color difference signals Pr _3, Pr _4, is continuously recorded by one track in the order of the color difference signals Pb _3, Pb _4.

FIG. 5 is a time chart showing the relationship between the luminance signal (Y) input to the recording system of the still video device and the luminance signal (Y) recorded on the track when recording a high definition image. . One screen is composed of the first field and the second field, of which FIG.
Shows the luminance signal of the first field. The luminance signal of the first field is composed of a large number of horizontal scanning lines H, and the luminance signal corresponding to one horizontal scanning line H is between two adjacent horizontal synchronizing signals S _H (hereinafter referred to as horizontal Exists in the synchronization period).

When recording the luminance signal, the changeover switch 2
The terminal a of 3 is brought into the connected state, and the magnetic head 6 is sequentially moved from the first track to the fourth track on the outer peripheral side of the magnetic disk 3. That is, when recording the luminance signal Y ₁ ,
When the magnetic head 6 records the luminance signal Y ₂ on the first track, the magnetic head 6 records on the second track, and when recording the luminance signal Y ₃ , the magnetic head 6 records on the third track. At the time of recording the luminance signal Y ₄ , the magnetic head 6 moves to the fourth position.
Recording is performed by moving to each track (see FIG. 4). Here, the Nth track does not mean the Nth track from the outermost periphery of the magnetic disk 3, but
It means a relative track number based on an arbitrary track.

As shown in FIG. 5, the frequency band of the luminance signals Y _{1 to} Y ₄ when written in the Y memory 16A is f.
When _H, to be extended 4 times longer when read from Y memory 16A, the frequency band of the luminance signal Y ₁ to Y ₄ to be recorded in the first through fourth track becomes f _H / 4. Due to the characteristics of the magnetic disk 3, the recordable band is limited. However, with such a configuration, it is possible to practically record a luminance signal in a band higher than that, and it is possible to record a high-definition image. It

FIG. 6 shows a color difference signal (Pr) input to the recording system of a still video device in recording a high definition image.
2 is a time chart showing the relationship between the color difference signal (Pr) recorded on the track. One screen is composed of the first field and the second field, of which,
FIG. 6 shows the color difference signal (Pr) of the first field. The color difference signal of the first field is composed of a large number of horizontal scanning lines H, and a color difference signal corresponding to one horizontal scanning line H exists within one horizontal synchronization period.

At the time of recording the color difference signal (Pr), the terminal b of the changeover switch 23 is brought into the connected state, and the magnetic head 6 is sequentially moved to the fifth track and the sixth track, and accordingly, the color difference signal Pr. ₁ is recorded on the fifth track, and the color difference signal Pr ₂ is recorded on the sixth track (see FIG. 4).

As shown in FIG. 6, the frequency band of the color difference signals Pr ₁ and Pr ₂ when written in the Pr memory 16B is f _H / 2, which is doubled in time when read from the Pr memory 16B. Therefore, the fifth and sixth
The frequency band of the color difference signals Pr ₁ and Pr ₂ recorded on the track is f _H / 4. Due to the characteristics of the magnetic disk 3, the band that can be recorded is limited. However, with such a configuration, it is possible to substantially record color difference signals in a band higher than that, and it is possible to record a high-definition image. It

At the time of recording the color difference signal (Pb), the terminal c of the changeover switch 23 is brought into the connected state, the magnetic head 6 moves to the seventh track and the eighth track, and although not shown, the color difference signal ( Pr), the color difference signal Pb ₁
Is recorded on the seventh track in the band of f _H / 4, and the color difference signal Pb ₂ is recorded on the eighth track in the band of f _H / 4.

Luminance signals Y _{5 to} Y in the second field
_8. The recording of the color difference signals Pr ₃ , Pr ₄ , Pb ₃ and Pb ₄ is the same as in the first field and is recorded on the (N + 8) th track (N = 1 to 8), respectively (FIG. 4). reference). The sync signal recorded on the magnetic disk 3 is not the sync signal ( _SH ) for high definition images, but is replaced with the sync signal (S) conforming to the NTSC system, for example.

FIG. 7 is a diagram showing bit allocation of the ID code. In FIG. 7, one horizontal scanning period (1
One bit of data is recorded in a period twice the horizontal synchronization period). The structure of this ID code is the same as that used in a normal still video device.
The code has a user's area. In this embodiment, this user's area is used to record information necessary for automatically performing a predetermined process when recording, erasing, reproducing or the like.

In the user's area, 2 bits are used to indicate the recording mode, and the first of field recording / frame recording is used.
2 bits to indicate the second field of field / frame recording, 1 bit to indicate the tracking direction, 7 bits to indicate the start track number, 7 bits to indicate the next track number, and 4 bits are allocated to indicate the component part (configuration screen) of the above, and the remaining 31 bits are unused or used for recording other information. These will be described in detail based on the table below. Table 1 below shows a bit pattern regarding the recording mode.

[0068]

[Table 1]

The standard signal standard recording (normal recording) mode means, for example, a system in which a standard image signal such as an image signal compatible with the NTSC system is recorded as it is without performing time axis expansion or screen division. This standard signal standard recording mode is indicated by setting 2 bits to "00".

The standard signal high-definition recording (track recording for each color difference signal) mode means a system for recording the luminance signal of the standard image signal and the color difference signal on different tracks. In this standard signal high-definition recording mode, 2 bits are set to "0".
Set to 1 ".

The high-definition signal recording (image division recording) mode is, for example, a high-definition image signal corresponding to the HDTV system is divided into a plurality of pieces on the screen, and a high-definition image signal corresponding to each divided screen is displayed. Is converted into a standard image signal by time-axis expansion and recorded on a plurality of tracks. In this case, the band is substantially expanded due to the time axis expansion. This high definition signal recording mode is indicated by setting 2 bits to "10". The recording method of this embodiment shown in FIG. 4 is this high definition signal recording mode.

The standard signal track separation frame recording mode is a system in which the standard image signal is frame-recorded as it is without performing time-axis expansion or screen division. This means a method of separating the field image signal recording track from each other. This standard signal track separation frame recording mode is indicated by setting 2 bits to "11". Table 2 below shows whether the field recording / frame recording is different or the first field / second in the case of frame recording.
The bit pattern regarding another of a field is shown.

[0073]

[Table 2]

The field record is indicated by setting 2 bits to "00". Also, the first field of the frame record is indicated by setting 2 bits to “01”, and the second field of the frame record is 2
Indicated by setting the bit to "10". Table 3 below shows a bit pattern regarding the tracking direction.

[0075]

[Table 3]

When the magnetic head 6 is moved from the outer peripheral side to the inner peripheral side of the magnetic disk 3, it is indicated by setting 1 bit to "0", and the magnetic head 6 is moved from the inner peripheral side to the outer peripheral side of the magnetic disk 3. When moving to the side, it is indicated by setting 1 bit to "1".

The head track number provided in the user's area shown in FIG. 7 means the absolute track number of the track in which the head constituent screen is recorded among the constituent screens of one screen. The bit pattern for the leading track number is the same as the bit pattern for the track number in the format.

The next track number means the absolute track number of the track in which the next configuration screen of the current configuration screen is recorded among the configuration screens of one screen. The bit pattern for this next track number is the same as the bit pattern for the track number in the format.
Table 4 below shows a bit pattern for each constituent screen that constitutes one screen.

[0079]

[Table 4]

The information on the constituent screen number indicates to which area of the divided screen the image signal of the track on which the ID data is recorded, and further the image signal,
Luminance signal (Y), color difference signal (Pr) and color difference signal (P
It shows which one of b).

As shown in FIG. 3, for example, in the present embodiment, each constituent screen constituting one screen has N
o. Configuration screen numbers 1 to 16 are assigned. No.
1 to 16 are 4 bits "0001" and "0", respectively.
010 "," 0011 "," 0100 "," 010 "
1 ”,“ 0110 ”,“ 0111 ”,“ 1000 ”,
"1001", "1010", "1011", "110"
0 ”,“ 1101 ”,“ 1110 ”,“ 1111 ”,
Indicated by setting to "0000".

Next, erasing will be described in detail. Figure 1
As shown in, the still video device 1 has an erase signal generating circuit 28, and this erase signal generating circuit 28 is connected to a terminal e of a changeover switch 29 for selecting recording / erasing. For example, when the erase switch on the operation unit 8 is operated, the terminal e of the changeover switch 29 is brought into the connected state under the control of the system control circuit 10, and the erase signal generating circuit 28 is activated to output the erase signal. The erasing signal is amplified by the recording amplifier 27, and the magnetic head 6 erases the image signal recorded on the predetermined track of the rotating magnetic disk 3.

This still video device 1 has a plurality of tracks on which image signals corresponding to one screen are recorded.
Set a predetermined track group due to the type of image signal,
The image signal is recorded only on the set predetermined track group, and all the image signals can be erased. In this case, the set predetermined track group (hereinafter,
The set track group) includes all tracks among the tracks in which the image signals corresponding to one screen are recorded, and some tracks selected by the user.

According to the present invention, in order to record a larger number of images in a fixed recording space on the magnetic disk 3, the image signals recorded on a part of all the tracks constituting one screen are recorded. That can be erased,
If you reproduce the image signal recorded on the remaining track,
The desired image is obtained. Examples of the set track group (erase pattern) of the image signal include all track erasure for erasing all the tracks on which the image signal corresponding to one screen is recorded, and the following patterns, for example.

In the case of frame recording, an erasing pattern for erasing only the image signal belonging to one of the two fields constituting one frame.
This erase pattern does not require high image quality and gives priority to the utilization efficiency of the magnetic disk by saving space on the magnetic disk, that is, more images are recorded in a fixed recording space on the magnetic disk. It is selected in such cases.

An erasing pattern for erasing only the color difference signal when the luminance signal and the color difference signal are recorded on different tracks. This erasing pattern is used when the color image once recorded on the magnetic disk is left as a black and white image to save space on the magnetic disk and improve the utilization efficiency of the magnetic disk, that is, a constant recording space on the magnetic disk. This is selected when recording more images.

FIG. 8, FIG. 9 and FIG. 10 are flowcharts showing the sequence of erasing the image signal.
Hereinafter, these flowcharts will be described. When erasing the image signal, all tracks on the magnetic disk 3 are pre-searched and the ID data recorded on each track is input to the system control circuit 10.

First, as will be described later, the image signal is reproduced and the image to be erased is selected by the operation unit 8 (step 101). Next, the erase switch of the operation unit 8 is turned on to enter the erase mode (step 102).

Then, the set track group is determined. Specifically, the erasing pattern is selected by the selection switch of the operation unit 8 (step 103). The erase patterns in this embodiment include all track erasure for erasing all the image signals corresponding to one screen, first field erasure for erasing only the image signal belonging to the first field in the case of frame recording, and frame recording. In (2), there are a second field erasing for erasing only the image signal belonging to the second field, and a color difference signal track erasing for erasing only the color difference signals (Pr) and (Pb). One or two patterns are selected from these erasing patterns.

After the erasing pattern has been selected for one screen in this way, it is judged whether or not all track erasing has been selected (step 104). All tracks are erased based on the ID data (step 105). Specifically, step 107 and step 109 described later are continuously executed.

When it is judged in step 104 that the all-track erasure is not selected, it is judged whether or not the first field erasure is selected (step 10).
6) If the first field erase is selected,
First field erase is executed based on the ID data (step 107).

When it is determined in step 106 that the first field erase is not selected, it is determined whether the second field erase is selected (step 1
08), if the second field erase is selected, the second field erase is executed based on the ID data (step 109).

If it is determined in step 108 that the second field erase is not selected, step 107
After performing the first field erasing in step 109 and after performing the second field erasing in step 109, it is determined whether color difference signal track erasing is selected (step 110), and color difference signal track erasing is selected. If so, color difference signal track erasing is executed (step 111). Note that step 108
If it is determined in step 110 that the second field erase is not selected, and it is determined in step 110 that the color difference signal track erase is selected, in step 111 all the color differences of the first field and the second field are selected. The signal is erased.

If it is determined in step 111 that color difference signal track erasing is not selected, erasing is not performed and this program is terminated. Although the pre-search is performed for all the tracks of the magnetic disk 3 in this embodiment, the pre-search may be omitted. Even if the pre-research is omitted, since the ID data is input to the system control circuit 10 when the image signal is reproduced in step 101, the erasing is executed based on the ID data.

In this embodiment, an erasing pattern for an image signal corresponding to one screen is selected, and when the erasing is executed, ID data is used to erase only the selected type of image signal. And erase all of the selected type image signals.

FIG. 9 shows the image signal of the first field when the first field erasure is selected in the determination of step 106, that is, when the track pattern shown in FIG. 4 is recorded. It is a flowchart which shows the sequence in the case of erasing.

The first track of the first field of the image to be erased (track pattern shown in FIG. 4 is determined based on the information on the first track number in the ID data recorded on each track of the magnetic disk 3, the constituent screen number, etc. (Corresponding to Y ₁ ) is detected, the magnetic head 6 is moved onto this head track (step 301), and the counter is set to n = 1 (step 302).

Next, it is determined whether or not n ≦ 8 (step 303). If n ≦ 8, the signal recorded on the track (the track on which the magnetic head 6 is currently located) is recorded. Is erased (step 304).

Upon completion of step 304, the next track in the first field of the image to be erased (Y ₂ in the track pattern shown in FIG. 4 is selected based on the information about the next track number in the ID data, the composition screen number, etc.).
Is detected), the magnetic head 6 is moved onto the next track (step 305), the counter n is incremented by 1 (step 306), and the step 30 is performed again.
Return to 3. When n> 8 in step 303, this program ends.

By executing the program shown in FIG. 9, the luminance signals Y _{1 to} Y ₄ and the color difference signals Pr ₁ and Pr recorded on the eight tracks which are continuously arranged in the radial direction of the magnetic disk 3 are executed.
₂ , Pb ₁ and Pb ₂ are sequentially erased. Similarly, when erasing the second field, based on the ID data, the example of the track pattern shown in FIG. 4, the luminance signal Y ₅ to Y
₈ , the color difference signals Pr ₃ , Pr ₄ , Pb ₃ and Pb ₄ are sequentially erased.

FIG. 10 shows steps 106 and 10 above.
In the judgment of No. 8, it is judged that the first field erasing and the second field erasing are not selected, respectively, and in the judgment of the step 110, it is judged that the color difference signal track erasing is selected, that is, shown in FIG. 9 is a flowchart showing a sequence for erasing color difference signals belonging to the first field and the second field when recorded in a track pattern.

On the basis of the ID data recorded on each track of the magnetic disk 3, the fifth track on which the color difference signal Pr ₁ belonging to the first field of the image to be erased is recorded is detected. The magnetic head 6 is moved onto the fifth track (step 501), the first counter is set to k = 1 (step 502), and the second counter is set to n = 1 (step 503).

Next, it is judged whether or not n ≦ 4 (step 504). If n ≦ 4, the signal recorded on the track (the track on which the magnetic head 6 is currently located) is recorded. Is erased (step 505).

When step 505 is completed, the next track in the image to be erased (see FIG.
(Corresponding to Pr ₂ in the track pattern shown in FIG. ₂ ) is detected, the magnetic head 6 is moved to the next track (step 506), the second counter n is incremented by 1 (step 507), and the step is repeated. 504
Return to. Steps 504 to 507 are repeatedly executed, and when n> 4 in step 504, it is determined whether or not k = 2 (step 508).

In step 508, when k = 2 is not satisfied, that is, when k = 1, the thirteenth color difference signal Pr ₃ belonging to the second field of the image to be erased is recorded based on the ID data. Track is detected, the magnetic head 6 is moved onto this 13th track (step 509), the first counter k is incremented by 1 to set k = 2 (step 510), and the second
The counter is set to n = 1 (step 503).

Next, it is judged whether or not n ≦ 4 (step 504). If n ≦ 4, the signal recorded in the track (the track where the magnetic head 6 is currently located) is recorded. Is erased (step 505).

Upon completion of step 505, the next track in the image to be erased (see FIG.
(Corresponding to Pr ₄ in the track pattern shown in FIG. ₄ ) is detected, the magnetic head 6 is moved to the next track (step 506), the second counter n is incremented by 1 (step 507), and the step is repeated. 504
Return to.

Steps 504 to 507 are repeatedly executed, and when n> 4 in step 504, k =
It is judged whether or not 2 is satisfied (step 508), and if k = 2 is judged at step 508, this program is terminated.

By executing the program shown in FIG. 10, the color difference signals Pr ₁ , recorded on the tracks of the magnetic disk 3,
Pr ₂ , Pb ₁ , Pb ₂ , Pr ₃ , Pr ₄ , Pb ₃ and Pb ₄ are sequentially erased.

Similarly, when two patterns are selected as the erasing pattern, the patterns are similarly erased based on the ID data. For example, when the first field erasing and the color difference signal track erasing are selected, in the example of the track pattern shown in FIG. 4, the luminance signals Y _{1 to} Y ₄ and the color difference signal Pr are selected.
₁ , Pr ₂ , Pb ₁ , Pb ₂ , color difference signals Pr ₃ , P
r ₄ , Pb ₃ and Pb ₄ are sequentially erased. Further, when the second field erasing and the color difference signal track erasing are selected, in the example of the track pattern shown in FIG. 4, the luminance signals Y _{5 to} Y ₈ and the color difference signals Pr ₃ , Pr ₄ , Pb ₃ , P.
b ₄ , the color difference signals Pr ₁ , Pr ₂ , Pb ₁ and Pb ₂ are sequentially erased.

As described above, according to the present invention, by utilizing the ID data, it is possible to erase only the image signal of the selected type and all the image signals of the selected type, so that the number of image signals is small. An image signal can be left in the area according to the purpose, and a wasteful track that cannot form a normal screen due to erasing unlike the conventional case does not occur, so that the utilization efficiency of the magnetic disk is improved.

In the present invention, the function of erasing the image signal means the case of simply erasing the image signal of a predetermined track and the case of erasing the image signal and recording (overwriting) a new image signal at the same time. Including.

FIG. 2 is a block diagram showing a configuration example of a reproduction system of the still video device of the present invention. In the still video device 1 shown in the figure, a magnetic disk drive mechanism 2 including a magnetic disk 3, a motor drive circuit 4, a spindle motor 5, a magnetic head 6 and a tracking drive circuit 7, an operation unit 8, a display unit ( (Not shown) and the system control circuit 10 are the same as those of the recording system shown in FIG.

With respect to the rotating magnetic disk 3, the magnetic head 6 is moved in a predetermined order on a predetermined track on which an image signal corresponding to one still image is recorded, that is, 16 tracks shown in FIG. , The image signal and the DPSK signal are sequentially read from each track.

In this case, in the present embodiment, of the image signals recorded on the 16 tracks corresponding to one still image, first, the luminance signals Y ₁ to Y ₁ to the signals recorded on the outer peripheral tracks of the magnetic disk 3 are recorded. Reading Y ₄ and Y memory 3
9A, and then the color difference signals Pr ₁ and Pr recorded on the tracks adjacent to the inner circumference side are written.
₂ is read and written to the Pr memory 39B, and then the color difference signals Pb ₁ and Pb ₂ recorded on the tracks adjacent to the inner peripheral side of these are read and written to the Pb memory 39C to write to the first field. after regeneration of the belonging image signals is carried out analogously to this luminance signal Y ₅ to Y ₈ belonging to the second field, the reproduction of the color difference signals Pr _3, Pr _4, Pb ₃ and Pb _4.

The image signal and the like read by the magnetic head 6 is first amplified by the reproduction amplifier 30.
The luminance signal (Y + S), the color difference signal (Pr + S), and the color difference signal (Pb + S) pass through a high-pass filter (not shown) and are input to the image signal reproduction processing circuit 31 and are FM-demodulated. The read DPSK signal passes through a band pass filter (not shown) and is input to the ID reproduction processing circuit 32 where it is DPSK demodulated to reproduce the ID data. This ID data is input to the system control circuit 10.

An envelope detection circuit 33 is connected to the output side of the reproduction amplifier 30, and the envelope detection circuit 33 detects the envelope (envelope) of the reproduction signal read by the magnetic head 6 and outputs it. The envelope detection signal according to the above is output to the system control circuit 10. In the system control circuit 10, the tracking drive circuit 7 is controlled so that the output of the envelope detection signal becomes maximum, and the magnetic head 6 is automatically tracked. Such automatic tracking of the magnetic head 6,
By controlling the rotational phase of the spindle motor 5 described later, a good still image can be obtained.

The luminance signal (Y + S), the color difference signal (Pr + S), and the color difference signal (Pb + S), which have been FM-demodulated by the reproduction processing circuit 31, pass through the low-pass filter 34 and are cut in the high frequency range. Then, the horizontal and vertical sync signals (S) are separated and extracted by the sync signal separation circuit 36 and input to the system control circuit 10 and the clock generation circuit 37, respectively. The horizontal and vertical synchronization signals (S) input to the system control circuit 10 are
For example, it is used for reading ID data. Further, the clock generation circuit 37 generates a memory write clock signal as a reference for writing to the memory, and the generated memory write clock signal is input to the A / D converter 38 and the memory control circuit 35, respectively. It

The luminance signal (Y) which has been FM demodulated and from which the horizontal and vertical synchronizing signals (S) have been separated is converted into a digital signal by the A / D converter 38 and the Y memory 39A.
Is temporarily stored in a predetermined address of. The color difference signal (Pr) demodulated by FM and separated from the horizontal and vertical synchronizing signals (S) is converted into a digital signal by the A / D converter 38 and is temporarily stored in the Pr memory 39B. Also,
Similarly, the color difference signal (Pb) is converted into a digital signal by the A / D converter 38 and temporarily stored in the Pb memory 39C.

[0120] The system control circuit 10, an image signal read by the magnetic head 6, the luminance signal Y ₁ to Y _8, the color difference signals Pr ₁ to PR _4, one in which one or the like of the color difference signals Pb ₁ ~Pb ₄ Is determined from the reproduced ID data, and the operation of the memory control circuit 45 is controlled based on this.

The memory control circuit 35 carries out the following control on the basis of the memory write clock signal from the clock generation circuit 37 while timing the writing to each of the memories 39A to 39C. That is, based on the memory write clock signal from the clock generation circuit 37, A
While the / D converter 38 is activated, the memory control circuit 35 activates the built-in write address counter to write the digital data of the luminance signal (Y) at a predetermined address of the Y memory 16A.

Further, the memory control circuit 35 activates a built-in write address counter on the basis of the memory write clock signal from the clock generation circuit 37 to set a predetermined address in each of the Pr memory 39B and the Pb memory 39C. Digital data of the color difference signal (Pr) and the color difference signal (Pb) is written. In addition,
The synchronization signal (S) included in the reproduction signal such as the luminance signal is
It is not sampled and therefore not written to memory.

The synchronizing signal generating circuit 40 outputs horizontal and vertical synchronizing signals ( _SH ) corresponding to the high-definition image signal and inputs them to the clock generating circuit 41. The clock generation circuit 41 generates a memory read clock signal which serves as a reference for reading from each memory, and the memory read clock signal is used as a reference for the memory control circuit 35 and D / D.
It is input to each A converter 42A. Further, this memory read clock signal is divided into ½ by the frequency divider 43 and then input to the D / A converters 42B and 42C, respectively.

The memory control circuit 35 performs the following control on the basis of the memory read clock signal from the clock generation circuit 41 while taking the timing of reading from the memories 39A to 39C. That is, based on the memory read clock signal from the clock generation circuit 41,
The memory control circuit 35 operates the built-in read address counter to read the digital data of the luminance signal (Y) from a predetermined address of the Y memory 39A, and the D / A converter 42A operates to read the digital data. The converted digital signal of the luminance signal (Y) is converted into an analog signal.

Further, based on the memory read clock signal from the clock generation circuit 41, the memory control circuit 35
Activates the built-in write address counter to read out the digital data of the color difference signal (Pr) and the color difference signal (Pb) from the predetermined addresses of the Pr memory 39B and the Pb memory 39C, respectively.
The / A converters 42B and 42C operate to convert the read digital signal of each color difference signal into an analog signal. In the memory control circuit 35, mode switching between writing control and reading control of the memory is controlled by a mode switching command signal from the system control circuit 10.

[0126] Also, the horizontal and vertical synchronizing signals from the synchronizing signal separation circuit 36 (S), and horizontal and vertical synchronizing signals from the synchronizing signal generating circuit 40 (S _H), respectively, also input to the system control circuit 10 Based on this, the rotation phase of the spindle motor 5 is controlled and used as a timing signal for other various operations.

In the case of reproducing such a high definition image, the memory read clock signal from the clock generation circuit 41 has a larger frequency than the memory write clock signal from the clock generation circuit 37, for example, four times. Have a frequency. Therefore, the frequency of the read clock signal of the luminance signal is four times the frequency of the write clock signal, and the frequency of the read clock signal of both color difference signals is twice the frequency of the write clock signal, which causes the magnetic Compared to the signal read by the head 6, the signal is compressed on the time axis and reproduced in the original state (state at the time of input to the recording system).

The luminance signal (Y), the color difference signal (Pr) and the color difference signal (Pb), which are analog signals, are respectively
After the high frequency band is cut by the low pass filters 44A, 44B and 44C, the synchronizing signal adding circuits 45A and 45
The vertical and horizontal synchronizing signals ( _SH ) from the synchronizing signal generating circuit 40 are added by B and 45C.

The luminance signal (Y + S
_H), color difference signals (Pr + S _H) and color difference signals (Pb +
S _H ) is output as a video signal through an output circuit (not shown), and a still image is reproduced on the connected display. The above-mentioned image signal erasing mechanism may be installed in such a reproducing system.

In this embodiment, the bit allocation of the ID code is configured as shown in FIG. 7, but sufficient information can be recorded to specify the track on which the image signal to be erased is recorded. The configuration is not limited to such a configuration.

Further, in the present embodiment, there are four erasing patterns, that is, all track erasing, first field erasing, second field erasing, and color difference signal track erasing, and it is possible to arbitrarily select from these four patterns. However, the erase pattern is not limited to this. For example,
In addition to these, in the track pattern shown in FIG. 4, the luminance signals Y ₁ and Y _{2 of} the first field, the color difference signal Pr ₁ ,
Pb ₁ , the luminance signals Y ₅ , Y _{6 of} the second field, and the color difference signals Pr ₃ , Pb ₃ are erased, and only the upper half of the screen in FIG. 3 is erased. In the track pattern shown in FIG. Luminance signals Y ₃ and Y _{4 of} one field, color difference signals Pr ₂ and Pb ₂ , and luminance signal Y of the second field
₇ , Y ₈ and color difference signals Pr ₄ and Pb ₄ are erased, and FIG.
You can also erase only the bottom half of the screen at.

Further, the erase pattern is predetermined, for example, all track erase, first field erase,
The erasing pattern may be set to any one of erasing the second field, erasing the color difference signal track, erasing the color difference signal track of the first field, and erasing the color difference signal track of the second field. When the erasing pattern is determined in advance, the usual erasing means, for example, the user manually operates to determine the track to be erased, moves the magnetic head on the track, and then performs the erasing. A mechanism may be provided. Further, a normal erasing means may be provided in this embodiment.

Further, in this embodiment, for the image signal corresponding to one screen, the number of tracks on which the luminance signal (Y) is recorded, the number of tracks on which the color difference signal (Pr) is recorded, and the color difference signal (Pb). The ratio to the number of tracks on which () is recorded is 4: 2: 2, but the ratio is not limited to this and may be, for example, 4: 1: 1 or 2: 2: 2.

In this embodiment, the number of magnetic heads for recording and reproducing image signals is one, but a plurality of magnetic heads may be provided in each of the recording system and the reproducing system. In such a case, each magnetic head may be, for example, a dedicated magnetic head provided for each of the luminance signal (Y), the color difference signal (Pr) and the color difference signal (Pb), or an image signal for one field. Corresponding magnetic heads (in this embodiment, eight magnetic heads arranged in parallel) can be cited.

In addition, although the case of frame recording has been described in the present embodiment, the present invention can be applied to an apparatus capable of field recording. Further, in this embodiment,
Although the color difference signal (Pr) and the color difference signal (Pb) are recorded on different tracks, they may be recorded on the same one or two or more tracks. In this case, the color difference signal (P
r) and the color difference signal (Pb) are line-sequentially recorded, and the color difference signal (Pr) and the color difference signal (Pb) are each divided into a plurality of parts within one horizontal synchronization period (for example, divided into the first half and the second half) Then, any method of recording may be used.

Further, in the present embodiment, the image signal corresponding to one screen is recorded, reproduced or erased in order from the track on the outer peripheral side of the magnetic disk 3, but the invention is not limited to this order. Further, in the present embodiment, the luminance signals Y ₁ , Y ₂ , Y ₃ , Y _{4 of} the first field and the color difference signals Pr ₁ , P _{1 are} arranged from the outer peripheral side to the inner peripheral side of the magnetic disk 3.
r ₂ , color difference signals Pb ₁ and Pb ₂ , second field luminance signals Y ₅ , Y ₆ , Y ₇ and Y ₈ , color difference signals Pr ₃ and Pr
₄ , the color difference signals Pb ₃ and Pb ₄ are continuously recorded one track at a time, but the track pattern on the magnetic disk 3 is not limited to this.

In the present invention, the image signal recording medium is
The recording medium is not limited to a magnetic recording medium such as a magnetic disk, and may be, for example, an optical recording medium or a magneto-optical recording medium. The still video device according to the present invention may have either one or both of the recording system and the reproducing system as described above. The still video device of the present invention has been described above based on the illustrated configuration example, but the present invention is not limited to this. In particular, regarding the circuit configurations of the recording system and the reproducing system, any one having the same function is included in the present invention.

[0138]

As described above, according to the still video apparatus of the present invention, the image signal of the type selected according to the purpose is erased, so that the space of the magnetic disk can be saved. Moreover, since all the image signals of the selected type are erased and the other image signals are not erased by mistake, some of the plurality of tracks to be erased should be erased as in the past. Will not be erased or a track that should not be erased will not be erased. For this reason, when erasing, there is no useless track that cannot form a normal screen, and therefore the utilization efficiency of the space of the recording medium is good.

In particular, when recording a luminance signal and a color difference signal separately on a plurality of tracks, such as recording a high definition image, the present invention is highly applicable. The still video device of the present invention has a simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a recording system of a still video device of the present invention.

FIG. 2 is a block diagram showing a configuration example of a reproduction system of the still video device of the present invention.

FIG. 3 is a schematic diagram showing an example of a storage area pattern of image signals in each memory.

FIG. 4 is a diagram showing an example of a track pattern formed on a magnetic disk.

FIG. 5 is a time chart showing a relationship between a luminance signal (Y) input to a recording system of a still video device and a luminance signal (Y) recorded on a track.

FIG. 6 is a time chart showing a relationship between a color difference signal (Pr) input to a recording system of a still video device and a color difference signal (Pr) recorded on a track.

FIG. 7 is a diagram showing an example of bit allocation of an ID code.

FIG. 8 is a flowchart showing a sequence of erasing an image signal.

FIG. 9 is a flowchart showing a sequence of erasing an image signal belonging to the first field.

FIG. 10 is a flowchart showing a sequence of erasing color difference signals.

[Explanation of symbols]

 1 still video device 2 magnetic disk drive mechanism 3 magnetic disk 4 motor drive circuit 5 spindle motor 6 magnetic head 7 tracking drive circuit 8 operation unit 10 system control circuit 11A, 11B, 11C low-pass filter 12 memory control circuit 13 sync signal separation circuit 14 Clock generation circuit 15A, 15B, 15C A / D converter 16A Y memory 16B Pr memory 16C Pb memory 17 Frequency divider 18 Synchronous signal generation circuit 19 Clock generation circuit 20A, 20B, 20C D / A converter 21A, 21B, 21C Low-pass filter 22A, 22B, 22C Sync signal adding means 23 Changeover switch 24 Recording processing circuit 25 ID recording circuit 26 Adder 27 Recording amplifier 28 Erase signal generating circuit 29 Changeover switch 30 Reproduction amplifier 1 Reproduction Processing Circuit 32 ID Reproduction Processing Circuit 33 Envelope Detection Circuit 35 Memory Control Circuit 36 Synchronous Signal Separation Circuit 37 Clock Generation Circuit 38 A / D Converter 39A Y Memory 39B Pr Memory 39C Pb Memory 40 Synchronous Signal Generation Circuit 41 Clock Generation Circuit 42A, 42B, 42C D / A converter 43 frequency divider 44A, 44B, 44C low-pass filter 45A, 45B, 45C sync signal adding means 101-111 steps 301-306 steps 501-510 steps

Claims (8)

[Claims] 1. A 1 composed of 1 or 2 fields
A still video device comprising a recording system having a function of recording an image signal corresponding to one screen on a plurality of tracks of a recording medium and a function of erasing the image signal recorded on the track. Sets a predetermined track group among a plurality of tracks on which image signals corresponding to one screen are recorded, erases the image signal recorded on this track group, and at this time, records on the track group. A still video device, wherein the still video device is configured to erase all image signals. 2. The still video device according to claim 1, wherein the image signal includes a luminance signal and a color difference signal. 3. The still video device according to claim 2, wherein the luminance signal and the color difference signal are separately recorded on a plurality of tracks. 4. The still video device according to claim 1, wherein the set track group is a set of all tracks on which image signals for one screen are recorded. 5. The still video device according to claim 1, wherein the set track group is a set of tracks in which image signals belonging to one field are recorded in frame recording. 6. The still video device according to claim 3, wherein the set track group is a set of tracks on which the color difference signals are recorded. 7. The still video device according to claim 1, wherein the type of image signal to be erased can be selected. 8. A still video device comprising a reproduction system for reproducing an image signal recorded on a recording medium by the recording system according to any one of claims 1 to 7, wherein the reproduction system includes a plurality of tracks. A still video device, characterized in that it is configured to synthesize and reproduce each of the recorded image signals.