JPH06150537A - Still video equipment - Google Patents

Abstract

(57) [Summary] [Structure] The recording system of the still video apparatus of the present invention comprises a magnetic disk drive mechanism 2, a system control circuit 10, a memory control circuit 12, A / D converters 13 to 14, memories 16 to 18, Sync signal generation circuit 19, D / A converter 20
To 22, Y signal processing circuit 23, C signal processing circuit 24, I
It has a D recording processing circuit 25, an adder 26, an image signal recording amplifier 27, a pilot signal generating circuit 28, a pilot signal recording amplifier 29 and the like. Input image signal (Y
+ S, RY, BY) is FM-modulated and recorded on a predetermined track of the magnetic disk 3 by the magnetic head 6A. At the same time, the pilot signal generated from the pilot signal generation circuit 28 is applied to the magnetic head 6B. Is recorded on the adjacent track. [Effect] High-accuracy time base correction is performed to prevent adverse effects due to jitter.

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 via an encoder.

Incidentally, the rotation of the magnetic disk during recording and reproduction is kept constant by the rotation control means of the spindle motor (3600 in the case of the NTSC system).
Although it is controlled so as to keep it at (rpm), uneven rotation may actually occur. Further, the center of rotation of the magnetic disk may be displaced from the center of the rotation axis of the spindle motor, the head touch on the magnetic disk may be incomplete, or the magnetic disk may be deformed over time. Due to such various causes, the reproduced image signal contains jitter that slightly changes in the time axis direction, and there is a problem that a still image displayed on the display fluctuates.

In particular, when reproducing a high-definition image signal in which the frequency band of the luminance signal is expanded, the influence of jitter becomes remarkable, so that a highly accurate time base correction device (TBC) is used.
However, as described above, in the method of storing the image signal in the memory according to the sampling pulse generated from the synchronization signal recorded on the magnetic disk, sufficient time-axis correction cannot be performed. I can't
It causes deterioration of the image.

As a technique for correcting the time axis according to the jitter, one of two kinds of pilot signals between the frequency band of the luminance signal and the frequency band of the color difference signal and having different frequencies is used as the luminance signal or the like. An image signal which is recorded on the recording track of, and generates a memory write clock containing a jitter component based on the recorded pilot signal at the time of reproduction and reads the image signal from the memory written according to the clock to obtain a still image. A recording or reproducing device is disclosed (Japanese Patent Laid-Open No. 2-177792).
issue).

However, in this image signal recording or reproducing apparatus, since the pilot signal is recorded while being superimposed on the image signal, the frequency of the pilot signal to be recorded will not overlap or approach the band of either the luminance signal or the color difference signal. This is not allowed, and is limited to a narrow range, and the signal level is also limited, and it is difficult to secure a sufficient S / N ratio. Therefore, it is not possible to perform time axis correction with high accuracy.

Further, the presence of the pilot signal lowers the S / N ratio of the image signal, which causes deterioration of the image quality.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a still video device capable of highly accurate time axis correction.

[0011]

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

(1) A still video device having a recording system for recording an image signal corresponding to one screen on a magnetic recording medium having a plurality of recording tracks, wherein the recording system is relative to the magnetic recording medium. And 1st and 2nd magnetic heads that can be moved, and pilot signal generating means for generating a pilot signal having a fixed period. The first magnetic head outputs the image signal to the predetermined magnetic recording medium. Still video apparatus, wherein the pilot signal generated by the pilot signal generating means by the second magnetic head is recorded on another track at the same time as recording on the other track.

(2) The still video device according to (1), wherein the pilot signal is recorded on a track adjacent to the track on which the image signal is recorded.

(3) The still video device according to (1) or (2), wherein the pilot signal is a sine wave or a rectangular wave having a constant period.

(4) The frequency of the pilot signal is
The still video device according to any one of (1) to (3) above, which is included in a frequency band of a luminance signal or a color difference signal forming the image signal.

(5) A horizontal synchronizing signal is recorded together with an image signal on the magnetic recording medium, and the frequency of the pilot signal is an integral multiple of the frequency of the horizontal synchronizing signal. Still video equipment according to any one of the claims.

(6) The frequency of the pilot signal is
The still video device according to (5) above, which is an even multiple of the frequency of the horizontal synchronization signal.

(7) The still video device according to any one of (1) to (6), wherein the image signal is divided into a plurality of tracks and recorded.

(8) A reproducing system for simultaneously reading and reproducing the image signal and the pilot signal recorded on the magnetic recording medium by the recording system according to any one of the above (1) to (6) by different magnetic heads. A still video apparatus having the above, wherein the reproduction system has a time axis correction means for performing time axis correction of the read image signal based on the read pilot signal.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred example of the still video apparatus of the present invention will be described in detail below with reference to 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 is
It has a system control circuit 10 for controlling various functions of the still video device described later. This system control circuit 10
It 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 images to be photographed, voice, various data relating to the images, 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 rotations of the spindle motor 5 are output from the spindle motor 5, and one rotation of the magnetic disk 3 starts from the center of the magnetic disk 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
Two magnetic heads 6A and 6B are installed. These magnetic heads 6A and 6B are arranged at intervals corresponding to one track pitch of the magnetic disk 3, and are continuously or intermittently (intermittently) simultaneously in the radial direction of the magnetic disk 3 by a stepping motor (not shown). It is designed to move. That is, at the time of recording and reproducing, the stepping motor is driven to drive the magnetic head 6
The magnetic heads 6A and 6B are moved to a predetermined track of the magnetic disk 3 and the magnetic heads 6A and 6B are placed at proper positions on the tracks so that the positions of the magnetic heads 6A and 6B are finely adjusted so that maximum input and output can be obtained. Perform auto-tracking to adjust.

The moving amount, moving speed and moving timing of the magnetic heads 6A and 6B 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 includes, for example, a recording mode selection switch for selecting one of field recording and frame recording, a head feed switch for moving the magnetic heads 6A and 6B to a predetermined track of the magnetic disk 3, and an image signal for the magnetic disk 3. A Rec switch for recording, a selection switch for normal / high-definition images relating to the recording processing system, etc. (none of which are shown) are provided as necessary. 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 9 is connected to the system control circuit 10. The display 9 includes, for example, the recording mode, normal / high definition, track number,
Information such as track recording / non-recording information, shooting date / time, presence / absence of loading of the magnetic disk 3, power source information, flash light emission information, and current time / required information are displayed by, for example, a liquid crystal or a light emitting element. Is displayed. In the case of a still video device having both a recording system and a reproducing system,
The display unit 9 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, a horizontal and vertical synchronizing signal (S) is added to the luminance signal by a synchronizing signal generating circuit (not shown) and output as a luminance signal (Y + S). If the still video device does not have an image pickup unit, these signals are
It is input from the external input terminal.

As shown in FIG. 1, a horizontal and vertical sync signal (S) is separated and extracted from a luminance signal (Y + S) by a sync signal separation circuit 11 and input to a system control circuit 10 and a memory control circuit 12, respectively. To be done. The luminance signal (Y + S) is converted into a digital signal by the A / D converter 13 and is temporarily stored in the Y memory 16.

The color difference signal (RY) is sent to the A / D converter 14
Is converted into a digital signal by and is temporarily stored in the RY memory 17. The color difference signal (BY) is converted into a digital signal by the A / D converter 15, and the BY memory 1
It is temporarily stored in 8.

The memory control circuit 12, based on the horizontal and vertical synchronizing signals (S) from the synchronizing signal separating circuit 11, A / D converters 13, 14, 15 and a Y memory 16,
It controls the operation of the RY memory 17 and the BY memory 18, respectively. That is, the memory control circuit 12
Generates a memory write clock signal based on the horizontal and vertical sync signals (S) from the sync signal separation circuit 11, activates the A / D converters 13 to 15 based on this signal, and causes the memory control circuit to operate. A write address counter (not shown) built in 12 is operated to write digital data to a predetermined address of each memory 16-18.

The memory control circuit 12 also generates a memory read clock signal on the basis of the synchronization signal from the synchronization signal generation circuit 19 and operates a read address counter (not shown) incorporated in the memory control circuit 12. , Y memory 16, RY memory 17,
The data is read from a predetermined address of the BY memory 18, and the D / A converters 20, 21 and 22 are operated to convert the digital signal of the read image signal into an analog signal.

In such a 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.

In the case of normal recording, the memory read clock signal based on the sync signal generated from the sync signal generating circuit 19 and the memory write clock signal for writing the image signal in each of the memories 16 to 18 are: Although the frequencies are substantially the same, in the case of high-definition recording or the like, the memory read clock signal has a smaller frequency (for example, half the frequency) than the memory write clock signal. Therefore, in the high-definition recording, the image signal is read out at a speed slower than the writing speed to the memories 16 to 18, whereby the time axis is expanded.

The pulse signal from the synchronizing signal generating circuit 19 is also input to the system control circuit 10, and the rotation phase of the spindle motor 5 is controlled based on the pulse signal.
It is used as a timing signal for various other operations.

Luminance signal (Y) obtained as described above
Is FM-modulated by the Y recording processing circuit 23, and the color difference signals (RY, BY) are FM-modulated by the C recording processing circuit 24.
Modulated and line-sequentialized. The Y recording processing circuit 23
In, the horizontal and vertical synchronizing signals (S) from the synchronizing signal generating circuit 19 are added to the image signal again. Further, in the C recording processing circuit 24, the color difference signals (RY, BY) are line-sequentialized by the timing signal obtained based on the synchronizing signal from the synchronizing signal generating circuit 19.

Further, the system control circuit 10 outputs an ID data signal relating to image information such as field recording / frame recording, normal recording / high definition recording, track number, and shooting date. Recording processing circuit 2
Reference numeral 5 DPSK-modulates a carrier (carrier wave) generated based on the sync signal from the sync signal generation circuit 19 based on the ID data signal.

The FM-modulated luminance signal (Y + S), color difference signal and DPSK signal are combined by the adder 26 to generate an image signal corresponding to one still image. This image signal is amplified by the image signal recording amplifier 27 controlled by the system control circuit 10, and is recorded on a predetermined track of the rotating magnetic disk 3 by one magnetic head 6A.

Next, the pilot signal generating means in the present invention will be described. Magnetic disk 3 for the above image signals
The pilot signal is recorded as follows in addition to the recording in That is, the pilot signal generation circuit 28
The pilot signal (P) is generated based on the synchronization signal from the synchronization signal generation circuit 19. The pilot signal (P) is amplified by the pilot signal recording amplifier 29, and is recorded simultaneously with the image signal on the track adjacent to the track for recording the image signal by the other magnetic head 6B (FIG. 5). reference).

The pilot signal generated from the pilot signal generating circuit 28 is preferably a sine wave or a rectangular wave having a constant period, and its preferable frequency is, for example, 4/35 to 4 / of f _SC. About 1, especially 1 /
1 to 3/1, specifically, 409 KH _Z (2
6f _H) ~14.5MH _Z about, especially 3.58MH _Z ~
It is 10.7MH _Z about. The frequency of the pilot signal is not limited to this value.

Since this pilot signal is recorded on a track different from the recording track of the image signal,
The frequency can be set without considering overlapping with the frequency band of the luminance signal, the color difference signal, or the DPSK signal.

FIG. 3 is a diagram showing an example of the relationship between the luminance signal (Y + S) input to the Y recording processing circuit 23 and the pilot signal (P). The luminance signal (Y) between two adjacent horizontal synchronizing signals (S) corresponds to one scanning line, and the pilot signal (P) is preferably an integral multiple of the horizontal synchronizing signal (S). More preferably, it is a sine wave that vibrates at an even multiple frequency.

The reason why the frequency of the pilot signal (P) is preferably an even multiple (2n times: n is a natural number) of the frequency of the horizontal synchronizing signal (S) is as follows.

Normally, an image signal for one field is recorded on one track of the magnetic disk 3, and in the standard, one field is 262.5H (the number of horizontal scanning lines). Therefore, the last scanning line is the horizontal synchronizing signal. It will be cut at half the interval, and the pilot signal will be cut here as well. In this case, it is preferable to match the joint between the pilot signal to be reproduced next connected and the pilot signal at the cut point, that is, to make the phases of both pilot signals coincide with each other, but the pilot signal (P) If the frequency of is a multiple of the frequency of the horizontal synchronizing signal (S), the phase shifts by 180 ° at this joint, and the pilot signal is temporarily disturbed at the joint. Therefore, it takes time for the disturbance to converge (eliminate), that is, it takes time for the phase servo lock by the PLL circuit 48 based on the pilot signal, and the time axis correction is not sufficiently performed although it is partial. There are cases. Further, when the frequency of the pilot signal (P) is not an integral multiple of the frequency of the horizontal synchronizing signal (S), the phase shift may occur at the joint as well, and the same effect may occur.

Note that, for example, when the frequency of the pilot signal is relatively high (when the frequency is high, the number of phase comparisons in the PLL circuit 48 increases, and finer control is possible), or when using a high-performance PLL circuit. In the above, since the above effect is negligibly small, the frequency of the pilot signal (P) may be an odd multiple of the frequency of the horizontal synchronizing signal (S) or may not be an integral multiple.

FIG. 4 is a diagram showing another example of the relationship between the luminance signal (Y + S) input to the Y recording processing circuit 23 and the pilot signal (P). The pilot signal (P) shown in the figure is a rectangular wave (pulse signal), and its frequency is preferably an integral multiple, more preferably an even multiple of the horizontal synchronizing signal (S) for the same reason as above. . The waveform of the pilot signal is not limited to a sine wave or a rectangular wave.

When recording the next image on the magnetic disk 3, for example, a head feed switch (not shown) in the operation unit 8 is operated to move the magnetic heads 6A and 6B in the radial direction of the magnetic disk 3 (for example, Move an even number of track pitches (for example, two track pitches) from the outer circumference side to the inner circumference side,
The image signal and its pilot signal are recorded in the same manner as described above. As a result, the magnetic disk 3 will be shown in FIG.
As shown in FIG. 5, recording tracks 60A for image signals (shown by diagonal lines in the figure) and recording tracks 60B for pilot signals (shown by lattice lines in the figure) are formed alternately.

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, the magnetic disk 3, the motor drive circuit 4, the spindle motor 5, the magnetic heads 6A and 6 are used.
The magnetic disk drive mechanism 2, the operation unit 8, the display unit 9 and the system control circuit 10, which are composed of B and the tracking drive circuit 7, are the same as those of the recording system shown in FIG.

With respect to the rotating magnetic disk 3, the magnetic heads 6A and 6B are respectively positioned on a predetermined track on which an image is recorded and a track on which a pilot signal corresponding to the image is recorded, so that the image signal and the pilot signal are simultaneously generated. read.

The image signal read by the magnetic head 6A is first amplified by the reproduction amplifier 30 for the image signal, of which the luminance signal (Y + S) passes through a high-pass filter (not shown) to the Y reproduction processing circuit 31. It is input and FM demodulated. In addition, color difference signals (RY, B-
Y) passes through a low-pass filter (not shown), is input to the C reproduction processing circuit 32, and is FM demodulated. Also, DP
The SK signal passes through a band-pass filter (not shown) and is input to the ID reproduction processing circuit 33 where it is DPSK demodulated to reproduce the ID data.

From the FM demodulated luminance signal (Y + S), the horizontal and vertical synchronizing signals (S) are separated and extracted by the synchronizing signal separating circuit 34 and input to the system control circuit 10 and the memory control circuit 35, respectively. The horizontal and vertical synchronizing signals (S) input to the system control circuit 10 are used for reading ID data, for example.

Further, the FM demodulated luminance signal (Y + S)
Is converted into a digital signal by the A / D converter 36,
It is temporarily stored in the Y memory 38. The FM-demodulated color difference signals (RY, BY) are converted into digital signals by the A / D converter 37 and temporarily stored in the C memory 39.

The memory control circuit 35, based on the horizontal and vertical sync signals (S) from the sync signal separation circuit 34, A / D converters 36, 37, Y memories 38 and C.
The operation of the memory 39 is controlled respectively. That is, the memory control circuit 35 operates the A / D converters 36 and 37 based on a pulse signal from a PLL circuit 48 described later, and also causes a write address counter (not shown) built in the memory control circuit 35 to operate. It is operated to write digital data to predetermined addresses in the Y memory 38 and C memory 39.

The memory control circuit 35 also generates a memory read clock based on the sync signal from the sync signal generation circuit 40, and operates a read address counter (not shown) incorporated in the memory control circuit 35. , Data is read from a predetermined address of the Y memory 38 and the C memory 39, respectively, and the D / A converter 41 is used.
Is operated to convert the read digital signal of the luminance signal into an analog signal. The horizontal and vertical synchronizing signals (S) from the synchronizing signal generating circuit 40 are added to the luminance signal converted into the analog signal by the adder 42 to obtain a luminance signal (Y + S).

Further, the memory control circuit 35 operates the synchronizing circuit 43 and the D / A converters 44 and 45 on the basis of the memory read clock based on the synchronization signal to alternately read the color difference signals (from the C memory 39). RY,
BY) is simultaneously output by the synchronizing circuit 43 for each horizontal scanning line, and digital signals of these color difference signals are converted into analog signals by the D / A converters 44 and 45, respectively.

In such a memory control circuit 35, 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 luminance signal (Y +
S) and the color difference signals (RY, BY) are output as a video signal via an output circuit (not shown), and a still image is reproduced on the connected display.

In the case of normal recording, the memory read clock signal based on the sync signal generated from the sync signal generation circuit 40 and the clock signal for writing the image signal in the memories 38 and 39 have substantially the same frequency. However, in the case of high-definition recording or the like, the memory read clock signal has a larger frequency (for example, twice the frequency) than the clock signal for writing the image signal in the memories 38 and 39. It Therefore, in the high-definition recording, the image signal is read out at a speed higher than the writing speed to the memories 38 and 39, whereby the time axis compression is performed.

The pulse signal from the synchronizing signal generating circuit 40 is also input to the system control circuit 10, and the rotation phase of the spindle motor 5 is controlled on the basis of the pulse signal.
It is used as a timing signal for various other operations.

On the output side of the reproducing amplifier 30,
An envelope detection circuit (not shown) is connected, and the envelope detection circuit detects the envelope (envelope) of the reproduction signal read by the magnetic head 6A, for example, and outputs an envelope detection signal corresponding thereto to the system control circuit 10. To do. In the system control circuit 10, the tracking drive circuit 7 is controlled so that the output of this envelope detection signal becomes maximum, and the magnetic heads 6A and 6B are automatically tracked. By performing the rotation phase control of the spindle motor 5 and the automatic tracking of the magnetic heads 6A and 6B, a good still image can be obtained.

Next, the time axis correction means in the present invention will be described. The signal read from the magnetic head 6B is amplified by the reproduction amplifier 46 and input to the pilot signal reproduction circuit 47, where the pilot signal (P) is reproduced. The reproduced pilot signal (P) is supplied to the phase comparator 49, the frequency divider 50 and the voltage controlled oscillator (VC).
O) 51 Phase Locked Loop (P
LL) circuit 48.

The voltage controlled oscillator 51 outputs a pulse signal (clock signal) having a frequency that is, for example, an integral multiple of the frequency of the pilot signal (P), and the frequency divider 50 outputs a pulse signal having the same frequency as the pilot signal (P). Then, this signal is input to the phase comparator 49. In the phase comparator 49, the pulse signal and pilot signal reproducing circuit 4
The phase of the pilot signal (P) from 7 is compared, and the control voltage signal corresponding to the phase difference is output,
The applied voltage of the voltage controlled oscillator 51 is controlled so that the phase difference becomes 0 or a constant value. As a result, the voltage-controlled oscillator 51 outputs a pulse signal having a frequency that follows a slight frequency change of the pilot signal (P), and the pulse signal is input to the memory control circuit 35.

As described above, the memory control circuit 35 writes the image signal in the memories 38 and 39 based on the pulse signal from the PLL circuit 48. During reproduction of an image, jitter occurs due to uneven rotation of the spindle motor 5, etc., and fluctuations in the time axis due to this jitter occur simultaneously in both the image signal and the pilot signal. In the reproduction system shown in the figure, the fluctuation of the time axis due to the jitter is caused by the PLL circuit 48 via the reproduced pilot signal (P).
It appears as a fluctuation in the cycle of the pulse signal output from the.
Therefore, based on this pulse signal, the memories 38, 39
When the image signal (luminance signal and color difference signal) is written to the memory, the image signal data is written in the memories 38 and 39 in a state where the time axis correction is performed, that is, a state in which the jitter component is not included. , Such data is stored in the memories 38, 39 by a clock signal having a constant cycle.
When it is read from and reproduced, a proper still image free from the influence of jitter can be obtained.

In order to improve the accuracy of such time axis correction, it is preferable that the frequency of the pilot signal is as high as possible within the range. When the pilot signal is recorded on the recording track of the image signal in an overlapping manner, the image signal and DP
The frequency of the pilot signal is limited so that it does not overlap or approach the band of the SK signal. However, in the present invention, the pilot signal is recorded on a track different from the recording track of the image signal, so that such a restriction is imposed. The frequency of the pilot signal can be set freely (the frequency of the pilot signal may be included in the band of the luminance signal or the color difference signal), and as a result, highly accurate time base correction becomes possible. . On the contrary, when expanding and setting the band of the luminance signal and the color difference signal as in high-definition recording,
Especially when the luminance signal and the color difference signal are recorded on different tracks, this can be done without considering the existence of the pilot signal, which is advantageous for improving the image quality.

When reproducing the next image, the head feed switch (not shown) in the operating section 8 is operated to move the magnetic heads 6A and 6B in the radial direction of the magnetic disk 3 by an even number of track pitches. The image signal and its pilot signal are reproduced on the desired track in the same manner as described above.

Although the field recording has been described in the above embodiment, the present invention is an apparatus capable of recording a frame, that is, an image signal for one screen in two tracks (fields). Can also be applied to. In this case, the still video apparatus is a magnetic disk drive mechanism provided with two or more sets of magnetic heads for image signals and magnetic heads for pilot signals.

The present invention also provides a high definition image (HDTV
The present invention can be applied to a still video device capable of performing recording and / or reproduction corresponding to a system etc.). A typical example of such a still video device is a device for expanding the band by expanding the time axis of an image signal and recording the expanded image signal in order to obtain a high-definition image, and then compressing the time axis for reproduction. Also, in order to further expand the band, the image signal may be divided into a plurality of tracks and recorded. In this case, a plurality of magnetic heads for image signals are used to record each of the luminance signal and the two color difference signals on separate tracks, and further, the screen is divided into a plurality (for example, four divisions vertically and horizontally), and each division is performed. It is possible to record the screen on one or more tracks, respectively.

Recording corresponding to such a high definition image,
In reproduction, jitter is likely to occur because the image signal is expanded on the time axis and recorded. Therefore, more accurate time axis correction is required, and the application of the present invention is significant.

The present invention is not limited to the case where the image signal and the pilot signal are recorded on the adjacent tracks (see FIG. 5). That is, for example, as shown in FIG. 6, the recording track 61 of the image signal is recorded in the outer peripheral area 3A of the magnetic disk 3.
A (indicated by diagonal lines in the figure) is formed side by side, and recording tracks 61B (indicated by lattice lines in the figure) of pilot signals corresponding to these are formed side by side in the inner peripheral area 3B of the magnetic disk 3. May be. In this case, the magnetic heads 6A and 6B are installed so as to be separated by several track pitches (for example, 25 track pitches).
A and 6B are configured to move integrally in the radial direction of the magnetic disk 3.

In the configuration shown in FIGS. 5 and 6, both magnetic heads 6A and 6B move integrally in the radial direction of the magnetic disk 3, but in the present invention, both magnetic heads 6A and 6B. 6B each independently magnetic disk 3
It may move in the radial direction.

The still video device of the present invention may be any one having 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 with reference to the illustrated configuration example, but the present invention is not limited to this.

[0073]

As described above, according to the still video apparatus of the present invention, it is possible to perform highly accurate time base correction and prevent image fluctuations due to jitter.

In particular, in the present invention, since the pilot signal is recorded on a track different from that of the image signal, the frequency of the pilot signal and the image signal are taken into consideration without considering the overlap between the frequency of the pilot signal and the frequency band of the image signal. The frequency band can be set, and as a result, more accurate time axis correction can be performed, and further higher image quality can be obtained by expanding the allowable range of the frequency band of the image signal.

[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 diagram showing an example of a relationship between a luminance signal and a pilot signal.

FIG. 4 is a diagram showing another example of a relationship between a luminance signal and a pilot signal.

FIG. 5 is a plan view showing an example of a track formation pattern on a magnetic disk.

FIG. 6 is a plan view showing another example of a track formation pattern on a magnetic disk.

[Explanation of symbols]

 1 still video device 2 magnetic disk drive mechanism 3 magnetic disk 3A outer peripheral side area 3B inner peripheral side area 4 motor drive circuit 5 spindle motor 6A, 6B magnetic head 7 tracking drive circuit 8 operation unit 9 display unit 10 system control circuit 11 synchronization signal Generation circuit 12 Memory control circuit 13, 14, 15 A / D converter 16 Y memory 17 RY memory 18 BY memory 19 Sync signal generation circuit 20, 21, 22 D / A converter 23 Y recording processing circuit 24 C recording processing circuit 25 ID recording circuit 26 adder 27 image signal recording amplifier 28 pilot signal generating circuit 29 pilot signal recording amplifier 30 reproducing amplifier 31 Y reproducing processing circuit 32 C reproducing processing circuit 33 ID reproducing processing circuit 34 synchronization signal separating circuit 35 Memory control circuit 36, 7 A / D converter 38 Y memory 39 C memory 40 Synchronous signal generating circuit 41 D / A converter 42 Adder 43 Synchronizing circuit 44, 45 D / A converter 46 Reproducing amplifier 47 Pilot signal reproducing circuit 48 PLL circuit 49 Phase comparator 50 Frequency divider 51 Voltage controlled oscillator 60A, 61A Image signal recording track 60B, 61B Pilot signal recording track

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H04N 9/79 G 7916-5C

Claims (8)

[Claims] 1. A still video device having a recording system for recording an image signal corresponding to one screen on a magnetic recording medium having a plurality of recording tracks, wherein the recording system is relative to the magnetic recording medium. First and second magnetic heads that can be moved to a predetermined position, and pilot signal generating means that generates a pilot signal having a constant period. The first magnetic head outputs the image signal to a predetermined magnetic recording medium. A still video apparatus, wherein the pilot signal generated by the pilot signal generating means by the second magnetic head is simultaneously recorded on another track. 2. The still video device according to claim 1, wherein the pilot signal is recorded on a track adjacent to a track on which the image signal is recorded. 3. The still video device according to claim 1, wherein the pilot signal is a sine wave or a rectangular wave having a constant period. 4. The still video device according to claim 1, wherein the frequency of the pilot signal is included in a frequency band of a luminance signal or a color difference signal forming the image signal. 5. A horizontal synchronizing signal is recorded together with an image signal on the magnetic recording medium, and the frequency of the pilot signal is an integral multiple of the frequency of the horizontal synchronizing signal.
5. The still video device according to any one of 1 to 4. 6. The still video device according to claim 5, wherein the frequency of the pilot signal is an even multiple of the frequency of the horizontal synchronizing signal. 7. The still video device according to claim 1, wherein the image signal is recorded separately on a plurality of tracks. 8. A still video apparatus having a reproducing system for simultaneously reading and reproducing the image signal and the pilot signal recorded on the magnetic recording medium by the recording system according to claim 1 by different magnetic heads. The still video device, wherein the reproduction system has a time axis correction means for correcting the time axis of the read image signal based on the read pilot signal.