JPH03256464A - Picture signal recorder - Google Patents

Abstract

PURPOSE:To correctly reproduce a picture signal even in the case of generating drop-out in a signal reproduced when reproducing the picture signal from a recording medium by recording the picture signal while adding plural reference signals for optimizing a transmission characteristic into the picture signal. CONSTITUTION:This picture signal recorder is equipped with an image pickup part 101, adders 102, 112, 126-129, low-pass filters 103 and 113, gamma correction processing circuits 104 and 114, recording signal processing circuits 105 and 115, image pickup part driving circuit 121, clock generating part 122, phase reference signal generator 123, ID signal generator 124, pilot signal generator 125, amplifiers 130 and 131, magnetic heads 132 and 133 and magnetic disk 134. Then, the picture signal is recorded while adding the plural reference signals for optimizing the transmission characteristic into the picture signal. Thus, even in the case of generating drop-out in the signal reproduced when reproduc ing the picture signal from the recording medium, the picture signal can correct ly be reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image signal recording device for recording image signals on a recording medium.

[Prior Art] Conventionally, there is a still video (hereinafter referred to as Sv) system as an image signal recording and reproducing apparatus that records and reproduces still image signals on a recording medium.

This SV system records a current TV signal, such as an NTSC television (TV) signal, on a magnetic disk called a video floppy by subjecting it to FM modulation. Therefore, the resolution of the image signal recorded and reproduced in this Sv system is sufficient to obtain the resolution equivalent to the current TV system on a TV monitor or the like.

However, in systems that handle still image signals such as the Sv system, the reproduced image may be flinted out by the printer, and in this case it has been pointed out that the image quality (especially resolution) is lower than that of silver halide photography. .

In addition, recently HDTV (H4gh Definity)
On TV) and other new TV systems are being considered. This HDTV system has approximately 1,000 scanning lines, which is approximately twice as many as the current NTSC system, and also has a corresponding horizontal signal band.

Therefore, it is necessary to develop the SV system into a still image recording and reproducing system that has a resolution of about 1000 pixels x 000 pixels (when a square screen is extracted), such as that obtained with HDTV. Ta.

However, if a new recording format is used to record high-quality still images at the level of 1000 pixels x 000 pixels (however, when a square screen is extracted) as described above, the conventional Sv A problem arises in that the system's playback device becomes unable to play and maintain compatibility.

As a method to solve such compatibility problems, the following method is being considered by the applicant (Japanese Patent Application No. 1983).
3-329417).

This method not only allows recording and playback of still image signals comparable to HDTV, but also maintains compatibility with conventional SV systems.
High definition 5till Vid
eo) method.

The CH5V method first samples a still image signal to be recorded at a predetermined period, and then converts the image signal formed by the sample values (pixels) obtained by sampling into multiple samples (for example, The image signal is divided into four (4) divided image signals. At this time, the number of samples of each of the divided image signals is set to be 500 pixels (vertical) x 6 SO pixels (horizontally) (however, regarding the luminance signal) or less. The plurality of divided image signals that are divided and formed as described above each have 500 pixels and 5 pixels.
This becomes an image signal that can be recorded and reproduced in the current SV system with 0 pixels or less, and is recorded on a plurality of tracks (for example, four) on a video floppy.

However, the format of the current SV system is to FM-modulate an image signal for one field and record it on a disk-shaped recording medium using one track.

Therefore, one frame of image signals is recorded using two tracks on the magnetic recording medium. Here, 1
An image signal for one field recorded on a book track has approximately 2,500 scanning lines in the case of the NTSC system.

Therefore, the image signal for one frame recorded on two tracks has about 1000 scanning lines.

In the CH3V method, the high-definition still image signal for one frame recorded using four tracks is approximately 1
000 scanning lines.

As described above, it is possible to record a high-definition still image signal having about 1000 zero scanning lines, but the horizontal resolution of the image signal recorded on each track is only about 500 zero scanning lines. I can't get it.

Therefore, as shown in FIG. 5, sampling is performed so that each pixel obtained by sampling is arranged offset.
The sample value of each pixel sampled in this way is recorded in analog, the reproduced signal is sampled again during playback, the sampled signal is temporarily stored in memory, and then interpolation processing is performed, as shown in Figure 6. As shown,
Also in the horizontal direction, it is made so that about 1000 lines of zero travel can be obtained.

By the way, in the above-mentioned CHSV system, when recording and reproducing image signals on a video floppy, a transmission form of "sample values" rather than "signal waveform" transmission is adopted, and the magnetic recording system and FM modulation/demodulation system The transfer characteristics of the transmission path, including the above, must satisfy Nyquist's first criterion.
, 433) - MUSE, a high-definition transmission system using satellites
-1 and patent application filed by the applicant in 1983: I29417
(see issue).

By using this method, even though the recording band of the image signal recorded on one track on the video floppy is the same as the current one, the image signal recorded on four tracks can be used for restoration. The resolution of the resulting image signal will be twice that of the current resolution in both the horizontal and vertical directions (however, as is clear from Figure 5,
The resolution of the restored image signal in the diagonal direction is lower than that in the horizontal and vertical directions. (Figure 7 is a diagram showing this situation in terms of two-dimensional spatial frequencies).

Now, it is clear without reference to the above-mentioned references that in order to correctly reproduce the original image through sample value analog transmission, it is important that the transmission system satisfy the following three conditions. .

■The group delay characteristic of the transmission line must be flat. ■The frequency amplitude characteristic of the transmission line must have point symmetry (skew symmetry) about f,/2 (sunblink frequency). ■Is the sample phase relative to the reproduced signal? The sample phase must match that of the recording signal. In order to satisfy the above (2), we must first obtain a highly accurate
5e Correction). This includes a method of adding a burst signal to a signal recorded on a recording medium during recording (as in NTSC color) and a method of multiplexing pilot signals. However, even if TBC is performed accurately using this method, it is not possible to compensate so that the sample phases of the recorded signal and the reproduced signal match, so generally one phase is used as the standard. The reference pulse is multiplexed into part of the image signal.

Furthermore, this reference pulse is often used for the detection of (1) and (2) above. For example, in the MUSE, which is a typical technique using a similar technique (sample value analog transmission), one reference pulse called a VZT pulse is inserted in the vertical (V) retrace period of the I field. Here, the VIT pulse uses a single pulse with a frequency of 2f, (f is the sampling frequency), first equalizes the transmission path so that it matches this pulse waveform or the reference waveform, and then matches the sample phase to the peak of the pulse waveform. The sample phase is controlled to match.

[Invention or problem to be solved B] However, if the reference pulse for controlling the transmission path characteristics and the sample phase for the reproduced signal is multiplexed only at one point in the V retrace period as in the past, In the magnetic recording and reproducing system of the present invention, there is a possibility that the reference pulse may be lost due to dropout of the recording medium.

In particular, in the case of the CHSV method, an image signal for one field is recorded on one track on a video floppy, and the image signal for a total of four fields recorded on four additional tracks is used to produce one screen. Because the sample phase information and transmission path characteristics that make up the still image signal vary for each track, it is necessary to correctly control the transmission path characteristics for each track and match the sample phase of the reproduced signal.

The present invention has been made in order to solve this problem, and it is possible to reproduce the image signal so that even if a dropout occurs in the reproduced signal when reproducing the image signal from the recording medium, the image signal can be reproduced correctly. An object of the present invention is to provide an image signal recording device that records an image signal on a recording medium.

[Means for Solving the Problems] In order to achieve the above object, the image signal recording device of the present invention adds and records a plurality of reference signals to the image signal for optimizing the transmission characteristics. It is structured like this.

[Operation] According to the present invention, even if a dropout or the like occurs during reproduction of an image signal from a recording medium, it is possible to correctly optimize transmission characteristics without missing a reference signal.

[Example] The present invention will be explained below using one embodiment of the present invention.

FIG. 1 shows a C to which the present invention is applied as an embodiment of the present invention.
1 is a diagram showing a schematic configuration of an H3V type image signal recording device.

In this embodiment, in order to simplify the explanation, an apparatus for recording monochrome image signals is shown, but in the case of color image signals, a color signal processing circuit may be added to the configuration shown in FIG. detailed explanation will be omitted.

In FIG. 1, lOl is an imaging unit that is controlled by a solid-state imaging device and a process circuit that preprocesses an image signal formed in the solid-state imaging device. Further, 121 is an imaging unit driving circuit for driving the solid-state imaging device in the imaging unit 101 in synchronization with a clock signal supplied from the clock generation unit 122 to output an image signal.

From the imaging unit 101, as shown in FIG.
In the solid-state image sensing device, offset-sampled pixel signals are read out two lines at a time or every two lines, and after being subjected to preprocessing, are supplied to adder circuits 102 and 112.

FIG. 2 is a diagram showing the arrangement of sub-sampled pixels in the solid-state image sensor of the imaging unit 101 of FIG. 1, during the odd field period.

The signals of the pixels of the line indicated by Bo (n is 1, 2.3, etc.) are simultaneously output, and the signal corresponding to the line An is sent to the adder circuit 102, and the signal corresponding to the line B0 is sent to the adder circuit. 112, and the pixel signals of the lines indicated by Cn and Dn (n is 1, 2.3, etc.) in the figure are simultaneously output during the even field period, and the signals corresponding to the line Cn are output simultaneously. A signal is sent to adder circuit 102 on line D. A signal corresponding to is supplied to the adder circuit 112.

On the other hand, the phase reference signal generator 123 generates two reference signals as shown in FIG.
For example, one horizontal opening period.

The adder circuits 102 .
112.

Then, the adder circuits 102 and 112 add the reference signal outputted from the phase reference signal generator 123 to the vertical retrace period part of the image signal outputted from the imaging section 101 as shown in FIG. , low pass filter (LPF) 103
, 113.

The LPFs 103 and 113 band-limit the image signals output from the adder circuits 102 and 112, and after removing unnecessary component signals for recording, the γ correction processing circuit 10
After performing γ correction processing in step 4, 114, the signal is supplied to a recording signal processing circuit 105°115.

The recording signal processing circuits 105 and 115 are the γ correction processing circuit 1
Emphasis processing is performed on the image signal that has been subjected to the γ correction processing and is output from 04 and 114.

Performs recording signal processing such as FM modulation, and adds it to the subsequent adder circuit 12.
6,127.

The ID signal generator 124 also converts the carrier signal of 13f u (f is the horizontal synchronization frequency) output from the clock generator 122 into information regarding the image signal output from a system controller (not shown) (for example, the year the photograph was taken). DPS, which is well-known by month, day, hour, minute, second, track number, etc.
K (Differential Phase
ft Keying) modulation to form an ID (index) signal and output it.
In addition circuits 126 and 127, the D signal is frequency multiplexed with the image signal subjected to recording signal processing output from the recording signal processing circuits 105 and 115, and is further supplied to addition circuits 128 and 129 at the next stage.

By the way, in the recording apparatus of this embodiment, there is a T on the playback side.
In order to perform BC, the TBC pilot signal is configured to be frequency multiplexed on the recorded image signal. Therefore, the first
As shown in the figure, the pilot signal generator 125 inputs the accurate carrier signal output from the clock generator 122, uses the input carrier signal to form a TBC pilot signal, and generates a TBC pilot signal. supply to.

In addition circuits 128 and 129, addition circuit 126,
The TBC pilot signal supplied from the pilot signal generator 125 is frequency-multiplexed onto the recording image signal supplied from the pilot signal generator 127, and is supplied to the recording amplifiers 130 and 131.

Recording amplifiers 130 and 131 include addition circuits 128 and 12.
At step 9, the TBC pilot signal or the frequency-multiplexed recording image signal is amplified and recorded by magnetic heads 132 and 133 on a magnetic disk 134 which is being rotated at a predetermined number of revolutions by a motor (not shown).

Incidentally, the magnetic heads 132 and 133 move the line A of the solid-state image sensor as shown in FIG. 2 during the first one field period.
An image signal for one field corresponding to pixel n is placed on the first track of the magnetic disk 134, and an image signal for one field corresponding to the pixel on line B7 of the solid-state image sensor is placed on the second track of the magnetic disk 134. be recorded at the same time. After completing the recording of one field's worth of image signals corresponding to the pixels of lines A and Bn of the solid-state image sensor on the magnetic disk 134 as described above, the magnetic head 132° 133 is moved by a head moving mechanism (not shown). The magnetic disk 134
During the next one field period, the image signals for one field corresponding to the pixels of the line Cn of the solid-state image sensor are transferred to the magnetic disk 134.
The image signals for one field corresponding to the pixels on line D of the solid-state image sensing device are stored on the magnetic disk 13 on the third track.
4 simultaneously recorded on the fourth track.

In addition, in the above recording, as shown in FIG. 3, the first track, the second track, the third track, and the fourth track of the magnetic disk 134 are respectively recorded in the well-known H-lined arrangement, and the adjacent tracks are This prevents the effects of crosstalk between the track and the track.

When reproducing a high-definition still image signal from the magnetic disk on which the high-definition still image signal is recorded as described above, the image signal recorded on the magnetic disk 134 is reproduced,
The reference signal added during the vertical blanking period of the reproduced image signal is separated, and the image signal reproduced from the magnetic disk 134 is optimized based on the separated reference signal.

As a method for optimizing the image signal as described above, as described above, the image signal reproduced from the magnetic disk 134 is
When optimizing using the R filter, the reference signal is separated from the vertical blanking period of the image signal after being optimized by the FIR filter, and the signal waveform of the separated reference signal and the signal waveform of the original reference signal The FIR
The setting coefficient of the filter is changed, and when resampling the image signal reproduced from the magnetic disk 134, a sampling pulse whose timing coincides with the maximum point of the signal waveform of the reference signal is applied, and this sampling By performing resampling using pulses, it becomes possible to accurately restore pixel signals formed by sampling performed during recording.

As described above, in this embodiment, the image signal reproduced from the magnetic disk 134 is optimized based on the reference signal separated from the image signal reproduced from the magnetic disk 134,
Further, a sampling pulse that is phase-synchronized with the reference signal is formed, and a resampler is performed in accordance with the sampling pulse.

However, due to dropouts etc. that occurred during playback,
It is possible that the reference signal added to the image signal is missing.

Therefore, in this embodiment, as shown in FIG. 4, one horizontal interperiod period is used during the vertical retrace period of the image signal.

Since two reference signals are added at intervals, even if one of the reference signals is missing, the other reference signal can be used. Dropouts can be prevented by envelope-detecting the reproduction signal (RF signal) reproduced by the magnetic head from the magnetic disk 134 during reproduction and monitoring whether the level of the detected signal exceeds a predetermined level. The aforementioned optimization and accuracy of the reproduced image signal can be achieved by detecting whether or not a dropout has occurred, and using the reference signal added during the period in which dropout does not occur among the periods in which the reference signal is added. This makes it possible to perform resampling.

In this embodiment, the number of reference signals added during the vertical retrace period of the image signal during recording is not limited to two.
The number may be increased depending on the performance of the recording medium.

[Effects of the Invention] As described above, according to the present invention, even if a dropout occurs in the reproduced signal when reproducing the image signal from the recording Is#, the image signal can be reproduced correctly. It becomes possible to provide an image signal recording device that records an image signal on a recording medium.

[Brief explanation of drawings]

FIG. 1 shows a CH to which the present invention is applied as an embodiment of the present invention.
A diagram showing a schematic configuration of an SV type image signal recording device, FIG. 2 is a diagram showing the arrangement of sub-sun-blinked pixels in the solid-state image sensor of the imaging section in FIG. 1, and FIG. FIG. 4 is a waveform diagram showing the reference signal added to the vertical retrace period of the image signal in the present invention, and FIG. 5 is a diagram showing the recording pattern of a high-definition still image signal for CHSV.
FIG. 6 is a diagram showing the arrangement of recording pixels recorded on a recording medium of a recording device compatible with the system. FIG. 7 is a diagram showing the two-dimensional spatial frequency of a recording image signal recorded on a recording medium by a recording device compatible with the CHSV system. In the figure. 101: Imaging section 102.112, 126, 127, 128, 129: Adder 103.113: Low-pass filter 104.114: γ correction processing circuit 105.115: Recording signal processing circuit 21: Imaging section drive circuit I22: Clock generator 123: Phase reference signal generator 124: ID signal generator 125: Pilot signal generator 1: +0, 131: Amplifier 132.133: Magnetic head 134: Magnetic disk

Claims (1)

[Claims] An image signal recording device for recording an image signal on a recording medium, characterized in that the device is configured to add and record a plurality of reference signals to the image signal for optimizing transmission characteristics.