JP2792665B2 - Image signal recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal recording apparatus that records an image signal obtained by imaging a subject on a recording medium.

[Conventional technology]

2. Description of the Related Art Conventionally, an electronic still video camera is known as an image signal recording / reproducing device that records an image signal obtained from an imaging device such as a video camera on a recording medium such as a magnetic disk and reproduces the recorded signal.

At present, known electronic still video cameras record and reproduce television signals conforming to the current television system (for example, NTSC system).
In the case of the system, the number of scanning lines is 525 lines / frame and the horizontal resolution is about 350 TV lines.

[Problems to be solved by the invention]

However, there is a strong demand for electronic still video cameras to have higher image quality along with higher image quality of video tape recorders in recent years.

In particular, in the case of an electronic still video camera, the current resolution is not sufficient due to the recording and reproduction of a still image signal, and even if a still image signal reproduced from a magnetic disk is printed, a silver halide Only an image with much lower image quality than a camera or the like can be obtained.

Recently, a new high-quality television system such as a high-definition television system has been proposed and experiments are being conducted.
When considering an electronic still video camera compatible with such a new television system, it is very difficult to record and reproduce in the current format, and a new format is required for the new television system. When using, it is necessary to ensure compatibility with the conventional format. However, the conventional format has a disadvantage that the band of the signal assigned to the color signal is absolutely narrow.

The present invention has been made in view of the above-described problems, and enables recording in a conventional format without deteriorating the image quality of a reproduced image.In addition, while maintaining compatibility with this format, not only luminance components but also color components can be recorded. It is another object of the present invention to provide an image signal recording apparatus capable of recording an image signal of sufficiently higher image quality than a conventional one on a recording medium.

[Means for solving the problem]

An image signal recording apparatus according to the present invention is an apparatus that records an image signal on a recording medium based on any one of a plurality of different recording modes, and includes an optical unit and an optical unit. A recording unit that converts the obtained image of the subject into an image signal based on one of the plurality of recording modes and records the image signal, and at least one of the plurality of recording modes In a recording mode, the recording device includes a control unit for controlling the optical unit so as to give the defocused image to the recording unit.

(Operation)

According to the above-described configuration, the image signal can be recorded on the recording medium based on the conventional format without deteriorating the image signal, and an even higher-definition image signal can be recorded on the recording medium.

〔Example〕

Hereinafter, the present invention will be described based on one embodiment of the present invention.

FIG. 1 is a diagram showing a schematic configuration of a recording unit of an electronic still video camera system to which the present invention is applied, as one embodiment of the present invention.

The operation of the electronic still video camera system shown in FIG. 1 during recording in the recording section will be described below.

In FIG. 1, when a start of a recording operation is instructed to a system controller 151 by an operation unit 152, the operation of incident light corresponding to an image of a subject (not shown) is controlled by the optical lens 101 and the system controller 151. The light is supplied to the prism 102 through a shutter 153, and the incident light is split into three directions by the prism 102, and after passing through optical low-pass filters (LPF) 154, 155, 156, respectively.
The images are supplied to the imaging surfaces of the imaging elements 103, 104, and 105, and the imaging images of the same subject are respectively formed on the imaging surfaces of the three imaging elements 103, 104, and 105. Each of the image sensors 103, 104, and 105 has about 600 pixels in the horizontal direction and about 500 pixels in the vertical direction. Although details will be described later, the focusing operation of the optical lens 101 is controlled by a lens driving circuit 170, the operation of which is controlled by a control signal from a system controller 151, and the imaging on the imaging surface of the imaging elements 103, 104, and 105 is performed. For example, the focus state is set in the high-definition recording mode, and the defocus state is set in the normal recording mode.

Note that, regarding the three imaging elements 103, 104, and 105, the position of the imaging surface of the imaging element 104 is different from the position of the imaging surface of the imaging element 103 in the horizontal and vertical directions with respect to the captured image of the subject.
The position of the imaging surface of the imaging element 105 and the position of the imaging surface of the imaging element 103 are set at the same position with respect to the captured image of the subject.

By the way, a green filter (not shown) is provided on the imaging surfaces of the imaging elements 103 and 104, and the system controller 15
When the start of the recording operation is instructed to the operation unit 152 by the operation unit 152, an instruction of the start of the recording operation is given from the system controller 151 to the synchronization signal generator 117, and the clock signal Ck is supplied from the synchronization signal generator 117 to the image sensor driving. The signal is supplied to the circuit 110. Then, the image sensor driving circuit 110 receives the supplied clock signal C.
The switch control circuit 158 drives the image sensors 103, 104, and 105 in synchronization with k, and switches the switch 1 in synchronization with the clock signal Ck.
The switching operation of 57 is controlled.

Green component image signal (hereinafter, referred to as G ₁ signals) from the image sensor 103 which is driven by the imaging element drive circuit 110 as described above is output, after the G ₁ signal which is band-limited by LPF 106, After being supplied to the camera process circuit 159 and subjected to processing such as γ correction, a red component video signal (hereinafter, referred to as an R signal) and a blue component video signal (hereinafter, referred to as an R signal) obtained from the image sensor 105 as described later. hereinafter referred to as B signal) formed by outputting a luminance signal Y ₁ by adding processing in an appropriate proportion.

Also, a green component video signal (hereinafter, G
₂ ) is output, and the G ₂ signal is
03 in the same manner as in the G ₁ signal outputted from, LPF 107, formed to output a luminance signal Y ₂ by the camera process circuit 160.

As described above, the luminance signals Y ₁ and Y ₂ formed in the camera process circuits 159 and 160 are added with the composite synchronizing signal Cs composed of the horizontal and vertical synchronizing signals generated by the synchronizing signal generator 117 in the adding circuits 113 and 114. After that, the clamp pulse C also output from the synchronization signal generator 117
A well-known clamp process is performed by the clamp circuits 118 and 121 in synchronization with p.

The luminance signals Y ₁ and Y ₂ to which the composite synchronizing signal has been added as described above and which have been subjected to the clamp processing are further modulated by the emphasis circuits 119 and 122 and the FM modulation circuits 120 and 123 so as to conform to the well-known electronic still video camera format. It is converted into a luminance signal and supplied to adders 130 and 131.

On the other hand, an R / B color filter having a configuration as shown in FIG. 2 is provided on the imaging surface of the imaging device 105, and an R signal and a B signal are output from the imaging device 105 driven by the imaging device driving circuit 110. The signals are sequentially output in the order based on the R and B color filters, and are separated and output to output terminals A and B by a switch 157 whose switching operation is controlled by a switch control circuit 158. The R and B color filters shown in FIG. 2 are arranged so that each grid corresponds to each pixel of the image sensor 105, and further, a red filter (R in the figure) and a blue filter (B in the figure). ) Are arranged as shown in the figure, and a clock signal Ck and a composite synchronizing signal Cs are supplied to the switch control circuit 158 from the synchronizing signal generator 117, and are synchronized with these signals. Te, a signal corresponding the output terminal a to a pixel position indicated by ○ mark in Fig. 2 of the switch 157 (hereinafter referred to as C ₁ signal) is output, indicated by △ mark in FIG. 2 from the output terminal B position pixel signal corresponding to (hereinafter, referred to as C ₂ signal) switching operation of the switch 157 so as to be output is controlled.

Then, the C ₁ and C ₂ signals output from the switch 157 are respectively
After the band is limited by LPF108 and 109, the camera process circuit
At 161 and 162, processing such as γ correction is performed, and the camera process circuit 15 is formed to form the luminance signal kings Y ₁ and Y ₂ as described above.
It is supplied to the subtracters 115 and 116 while being supplied to 9,160.

By the way, the subtractor 115, 116 has a camera process circuit 159, 1
The luminance signals Y ₁ and Y ₂ output from 60 are supplied after being band-limited by the LPFs 111 and 112, and the subtracters 115 and 116 subtract the luminance signals Y ₁ and Y ₂ from the C ₁ and C ₂ signals. color-difference line-sequential signal D ₁ corresponding to the C ₁ signal by thing is output from the subtracter 115, the color-difference line-sequential signal D ₂ corresponding to the C ₂ signal is output from the subtracter 116.

The color difference line-sequential signal D ₁ is supplied to the clamp circuit 124, and the color difference line-sequential signal D ₂ is supplied to the clamp circuit 127. still,
Sequential signal D ₁ color difference line corresponds to the luminance signal Y ₁ which is formed on the basis of the G ₁ signal output by the image sensor 103, also sequential signal D ₂ color difference line in G ₂ signal output from the imaging element 104 corresponds to the luminance signal Y ₂ which is formed on the basis.

The color difference line-sequential signals D ₁ and D ₂ output from the subtracters 115 and 116 are subjected to a well-known clamp process in the clamp circuits 124 and 127 in accordance with the clamp pulse Cp output from the synchronization signal generator 117, and then the emphasis circuit 125,
128, and are converted into FM-modulated color difference line-sequential signals conforming to the format of a known electronic still video camera by FM modulators 126 and 129, respectively, and supplied to adders 130 and 131.

An index (ID) signal corresponding to information (for example, recording year, month, day, or recording time, minute, second, etc.) set by the operation unit 152 in the system controller 151 prior to the above-described recording operation. From the ID signal generator 132,
The horizontal synchronization signal H supplied from the synchronization signal generator 117
In synchronization with the signal 13f _H having 13 times the frequency of,
It is generated in at least a part of the period corresponding to the vertical blanking period of the video signal, and is supplied to the adders 130 and 131.

As described above, the adder 139 is supplied with the FM modulated luminance signal Y ₁ , the FM modulated color difference sequential signal D _1, and the ID number.
The adder 130 frequency-multiplexes these kinds of signals, so that the adder 130 outputs one frame of recorded video signal conforming to the format of a known electronic still video camera, and supplies the signal to the field switch 133. The adder 131 is supplied with the FM-modulated luminance signal Y ₂ , the FM-modulated color-difference line-sequential signal D _2, and the ID signal. 1 outputs a recorded video signal for one frame conforming to the format of a known electronic still video camera, and supplies the signal to a field switch 134 via a mode switch 164.

On the other hand, the magnetic disk 150 is rotationally driven in advance by a motor 146 prior to a recording operation start instruction from the operation unit 152, and the motor 146 responds to a vertical synchronization signal V output from the synchronization signal generator 117. The motor is controlled by a motor control circuit 148 so as to rotate at a predetermined phase. That is, PG
The position of a PG pin (not shown) provided on the magnetic disk 150 is detected by the detector 147, and the PG pulse generator 149 detects the position of the PG pin every time the PG detector 147 detects that the PG pin has passed. Generates a PG detection pulse and generates the P
By supplying the G detection pulse and the vertical synchronization signal V generated by the synchronization signal generator 117 to the motor control circuit 148, and controlling the motor 146 so that the two have a predetermined phase relationship,
The magnetic disk 150 is rotated in synchronization with the vertical synchronization signal V.

The PG detector pulse output from the PG pulse generator 149 is supplied to a system controller 151. The system controller 151 synchronizes the field changeover switches 133 and 134 with A in FIG. By switching between the B side and the B side, the recording video signals output from the adders 130 and 131 are switched every one field and supplied to the recording amplifiers 135 to 138.
The recorded video signal amplified by 5-138
Supplied to the magnetic heads 141 to 144 arranged on a radius of
It is recorded on the magnetic disk 150. The magnetic head 1
Reference numerals 41 to 144 denote the magnetic disk 15 by the head moving mechanism 145.
The head moving mechanism 1 is movable from the system controller 151 by operating the operation unit 152.
A movement instruction signal is supplied to 45, and the magnetic heads 141 to 144 are moved to an arbitrary position on the magnetic disk 150.

The mode switch 164 is turned on / off by the system controller 151 in response to an instruction from the operation unit 152.
In the recording apparatus of the present embodiment, one frame of the video signal obtained from the imaging devices 103 and 105 is transferred to the magnetic disk 150 by using the magnetic heads 141 and 142.
A normal recording mode for recording on the upper two recording tracks,
A high-definition recording mode in which one frame of video signal obtained from each of the image pickup devices 103, 104, and 105 is recorded on four recording tracks on the magnetic disk 150 using the magnetic heads 141, 142, 143, and 144; The recording mode in which the video signal is recorded is selected by operating the operation unit 152. That is, when the high-definition recording mode is selected on the operation unit 152, the system controller 151 turns on the mode switch 164 and supplies the recording video signal output from the adder 131 to the field switch 134. Is recorded on four concentric recording tracks formed adjacent to each other on the magnetic disk 150, and when the normal recording mode is selected, the system controller 151 sets the mode changeover switch 164 to the OFF state, and performs addition. By preventing the recording video signal output from the adder 131 from being supplied to the field changeover switch 134, only the recording video signal output from the adder 130 is formed on two adjacent concentric circles on the magnetic disk 150. Is recorded on the recording track of the shape.

FIGS. 3A, 3B and 3C show the arrangement and reproduction of pixels corresponding to video signals recorded in a high-definition recording mode on a magnetic disk in the electronic still video camera system of this embodiment. a diagram showing the relationship between the arrangement of pixels at the interpolation, FIG. 3 (a) is G (○ mark in the drawing G _1, Is the G ₂ ) signal (or luminance signal Y ₁ , Y ₂ ), and (B) is the R signal
(In the figure, ○ mark is R ₁ , Is R ₂ ) signal (or color difference signal RY), (C) is B
(The circle in the figure is B ₁ , Indicates the B ₂ ) signal (or the color difference signal BY).

As shown in FIG. 3, the number of pixels corresponding to the video signal recorded on the magnetic disk is larger than the luminance signal Y by the color difference signal RY.
And BY are smaller, but in the format of the electronic still video camera, the band allocated to the color signal is narrower than the band of the luminance signal, and the color signal does not require much resolution compared to the luminance signal. Because.

Further, the R signal (or color difference signal RY) and the B signal (or color difference signal BY) of the video signal recorded in the high-definition recording mode on the magnetic disk as described above.
The positional relationship on the high definition screen is as shown in FIG. 4 (A).

That is, the resolution in the vertical direction is increased by arranging the scanning lines of the second frame so as to interleave between the scanning lines of the first frame, and the resolution in the horizontal direction is obtained by offsetting the pixel arrangement for each line. As a result, a high-definition image can be obtained. At this time, if the color signal does not have a certain level of resolution in the horizontal and vertical directions, a high-definition image cannot be obtained. Therefore, as shown in FIG. By recording a color difference line-sequential signal as shown in FIG. 4 (A) using a filter, it is possible to improve the horizontal and vertical resolution of the color signal in a balous manner.

FIGS. 4 (B), (C) and (D) show other combinations of recording of color difference line sequential signals, and FIGS. 4 (C) and (D) show, as shown in FIG. The resolution of the color signal in the vertical direction is lower than that in FIG. 4 (A), and a high-definition image cannot be obtained. However, FIG. 4 (B) has the same resolution as FIG. 4 (A). . In order to obtain the arrangement of the color signals as shown in FIG. 4 (B), for example, an RB color filter having a configuration as shown in FIG. 6 may be used.

In this embodiment, the color difference signals RY, B- of the pixel arrangement shown in FIGS. 3B and 3C are obtained by the above-described method.
The signal obtained from the image sensor 105 provided with the R and B color filters as shown in FIG. 2 is formed on the image sensing surface of the image sensor 105 via the optical LPE 156 in advance. Therefore, the color signal recorded on the magnetic disk in the high-definition recording mode does not suffer from image quality deterioration due to signal folding.

 Next, the operation of the lens driving circuit 170 will be described.

FIG. 7 shows a first configuration example of the lens driving circuit 170. 8
01 is an adder, signal a is a control signal (digital value) for AF (auto focus) from the system controller 151, and signal b is a signal for opening and closing the shutter 153. The signal C is a switching signal of high definition recording mode / normal recording mode, controls the switching circuit S _1.

Switch circuits S ₁ is turned ON when the normal recording mode, inputs the defocus data D _F representing a certain value to be generated from the defocus data generator 802 (digital value) to the adder 801. That is, signal a contrast value such that always focus state with respect to the optical lens 101 is outputted from the system controller 151, the switch circuits S ₁ and the adder 801 to the signal a, forcibly By adding a constant value “D _F ”, a predetermined defocus state is realized.

The state of the optical system in the above operation will be described with reference to FIG.

8A to 8C, reference numeral 901 denotes an optical lens 101, a shutter 153 prism 102, and an LPF 154 (1) shown in FIG.
55, 156), and 902 is the first optical system.
The image pickup devices 103, 104, and 105 in the figure are collectively referred to as image pickup devices.

FIG. 8A shows a state of the optical system when capturing and recording a still image in the high-definition recording mode. In this case, the symmetric image is focused on the imaging surface of the imaging element 902.

FIG. 9B shows the state of the optical system when capturing and recording a still image in the normal recording mode. In this case, the focus is slightly closer to the side than the symmetric object. That is, the symmetric object is in a defocused state on the imaging surface of the imaging element 902. The amount of this defocus is controlled by the lens driving circuit 170 so as to have a predetermined value. By setting the predetermined defocus state in this way, as shown in FIG. 8 (d), the MTF is lowered as compared with the in-focus state, thereby causing a wrapping which occurs when a still image is recorded / reproduced in the normal recording mode. The components can be within visual tolerance.

As a method for obtaining the same defocusing effect as in FIG. 8B, it is conceivable to focus on a side slightly distant from the symmetric object as shown in FIG. 8C.
Not only is it more likely that aliasing after playback will occur on the back (background) side of the symmetrical object, but if there is another focused object on the back side, it will give the viewer an out-of-focus impression. Sometimes.

On the other hand, in general shooting, there are not many objects other than the symmetric object on the side closer to the symmetric object, and it may give an unpleasant impression such as folding back interference and blurred focus as described above. Is low.

FIG. 9 shows a second configuration example of the lens drive circuit 170 of FIG. 1002 is an adder, signal a is a control signal (digital value) for AF (Auto Focus) from the system controller, and signal b is a shutter open / close signal. The signal C is a switching signal of high-definition recording / normal recording mode, controls the switching circuit S _2. ROM
(Read only memory) 1001 is an added value _DF for obtaining a predetermined amount of defocus state according to the AF control signal a.
A memory table which outputs, supplying the added value D _F to the adder 1002 via the look switch circuit S ₂ in the normal recording mode.

That is, the value of the signal a is output from the system controller 151 so that the optical lens 101 is always in focus. And the switch circuit S ₂ and the adder
A predetermined defocus state is realized by forcibly adding an appropriate addition value _DF to the signal a according to the AF control signal a by the ROM 1001 and the ROM 1001.

The ROM 1001 can also be realized by an arithmetic circuit.

The first and second embodiments of the lens driving circuit 170 have been described above. Here, it is assumed that all the AF control signals are digital values, but the same operation as that of the present embodiment can be realized even if the AF control signals are analog values.

That is, in the case of controlling by an analog signal, for example, in the case of FIG.
_It is sufficient if it is a constant voltage source that generates _{F. In} the case of FIG.
An A / D converter may be provided in a stage preceding 1001 and a D / A converter may be provided in a stage subsequent to 1001.

Further, the present invention shown in the above-described embodiment can obtain the same effect even when an imaging and recording device for recording a moving image signal is applied.

Further, the recording unit of the electronic still video camera system shown in the present embodiment has a reproducing unit, which will be described later, in order to remove time-axis fluctuations that occur during reproduction of a video signal. and the manner recorded in the magnetic disk a signal 13f _H output in synchronization with the horizontal synchronizing signal H which is outputted from the synchronization signal generator 117 from the generator 132 together with the recording video signal.

Incidentally, the ID signal output from the ID signal generator 132 in synchronism with the signal 13f _H is generated during at least a portion of the period of time corresponding to the vertical blanking interval of the video signal, during other period, the signal 13f _H is generated such that the position of the zero cross coincides with the rising position of the horizontal synchronization signal H output from the synchronization signal generator 117.

FIG. 5 is a diagram showing a schematic configuration of a reproducing unit in the electronic still video camera system of the present embodiment.

Hereinafter, the operation of the electronic still video camera system shown in FIG. 5 at the time of playback in the playback unit will be described.
Note that the playback unit in the electronic still video camera system according to the present embodiment includes both the video signal recorded based on the normal recording mode and the video signal recorded based on the high definition recording mode in the recording unit shown in FIG. The following is a description of a reproducing operation of a video signal recorded on a magnetic disk based on the high definition recording mode.

In FIG. 5, when the start of the reproducing operation and the reproduction track number are instructed by the operation unit 276, the system controller 275 sends an instruction to the head moving mechanism 285, and the operation unit 27
The magnetic heads 201, 202, 203, and 204 are moved over the recording tracks of the magnetic disk 286 designated in step 6.

On the other hand, when the operation of starting the reproducing operation of the magnetic disk 286 is instructed by the operation unit 276, the motor control circuit 282 operates according to the instruction of the system controller 275, and the motor 281 operates in response to the vertical synchronizing signal V supplied from the system controller 275. Is controlled to rotate in the phase of. That is,
The position of a PG pin (not shown) provided on the magnetic disk 286 is detected by a PG detector 283, and the PG detector 283 detects the passage of the PG pin each time the PG pulse generator 284 is detected. Generates a PG pulse, supplies the generated PG detection pulse and the vertical synchronization signal V generated by the system controller 275 to the motor control circuit 282, and controls the motor 281 so that the two have a predetermined phase relationship. By doing so, the magnetic disk 286 is rotated in synchronization with the vertical synchronization signal V.

As described above, when the magnetic heads 201, 202, 203, and 204 are moved onto arbitrary recording tracks adjacent to each other on the magnetic disk 286, and the rotation of the magnetic disk 286 by the motor 281 is stabilized, the magnetic heads 201, 2
The reproduced signals reproduced by 02, 203 and 204 are
After amplification at 5,206,207,208, the preamplifier 209,2
The reproduced signal amplified by the pre-amplifiers 209 and 210 is amplified by the
The reproduced signals amplified by the preamplifiers 211 and 212 are supplied to a field switch 214.

The field changeover switches 213 and 214 are controlled by a system controller 275 to perform a switching operation.
A PG detection pulse output from the PG pulse is input, and the field changeover switches 213 and 214 are switched between the A side and the B side in FIG.
A reproduction signal reproduced by the magnetic head 201 and the magnetic head 203 is output from the magnetic head 201 and the magnetic head 20 at the same time.
2 and a reproduction signal reproduced by the magnetic head 204 are simultaneously output.

The signals output from the field changeover switches 213 and 214 are supplied to high-pass filters (HPF) 215 and 221 and band-pass filters (BPF) 231, 241 and 271 and 272, respectively.

The HPFs 215 and 221 extract FM-modulated luminance signals from the reproduction signals supplied from the field changeover switches 213 and 214, and the extracted FM-modulated luminance signals are equalized by the equalizer circuits 216 and 22.
The frequency characteristics are corrected by 2 and the signals are suppressed to a predetermined level to prevent inversion by limiter circuits 217 and 223, and then FM demodulated by FM demodulators 218 and 224. Then, excess frequency components are removed by LPFs 219 and 225, and the de-emphasis circuit 22
At 0,226, a process reverse to the emphasis process performed at the time of recording is performed, and the result is output as a luminance signal including a synchronization signal.

In BPF231,241, the field changeover switches 213,21
The FM-modulated chrominance line-sequential signal is extracted from the reproduction signal supplied from 4, and the extracted FM-modulated chrominance line-sequential signal is equalized with the equalizer circuits 232 and 242, the limiter circuits 233 and 243, and the FM demodulator as in the case of the luminance signal described above. 234, 244, LPFs 235, 245 and de-emphasis circuits 236, 246 restore the original color difference line sequential signals.

As described above, the luminance signal including the synchronization signal output from the de-emphasis circuits 220 and 226 is output to the synchronization signal removal circuit 291,
After the synchronization signal is removed at 292, the signal is supplied to analog-to-digital (A / D) converters 227 and 228 and the LPFs 229 and 2
After the extra frequency component is removed via 30, the adder 237,
247, where the de-emphasis circuits 236,246
The R signal and the B signal are sequentially output from the adders 237 and 247 by the addition to the color difference line sequential signal output from the A / D converter 23.
Supplied to 8,248. In addition, in the above-described addition processing of the luminance signal and the color difference line sequential signal, the time axes coincide with each other by a delay circuit (not shown) so that the corresponding luminance signal and color difference line sequential signal are added to each other. .

In BPF271, 272, the field changeover switches 213, 21
4 is supplied from the extracted signals 13f _H from the reproduced signal, it is supplied to the write clock signal generator 273. The write clock signal generator 273 has a de-emphasis circuit 2
Synchronization signals separated by the synchronization signal separation circuits 239 and 240 from the luminance signal including the synchronization signal output from the 20,226 are supplied, and the write clock signal generator 273 uses these signals to write to the A / D converters 227,228,238,248. Form a clock signal.

Hereinafter, the operation of the write clock signal generator 273 will be described.

A reproduction signal reproduced from a recording track on the magnetic disk 286 by the magnetic head 201 or 202;
The reproduction signal reproduced by 203 or 204 has a time axis fluctuation, and the signal separated by BPF 271 and 272
Since 13f _H is separated from the reproduced signal, the same time axis fluctuation as the reproduced signal occurs.

Therefore, in order to cause the A / D converters 227, 228, 238, and 248 to perform A / D conversion following the time axis fluctuation, a PLL (Phase Locked Loo) provided in the write clock signal generator 273 is provided.
p) forming a write clock signal synchronized in phase with the signal 13f _H separated from BPF271,272 by the circuit.

In addition, in the formation of the write clock signal in the write clock signal generator 273, the rising position of the horizontal synchronizing signal of the video signal and the signal
Since the zero cross position of f _H is recorded in the manner consistent, are separated by the synchronizing signal separation circuit 239, the signal 13f _H supplied separated by the horizontal synchronizing signal of the rising edge position and BPF271,272 supplied as the zero-crossing position of the match, and the like to form the write clock signal by the PLL circuit in the write clock signal generator 273 after the phase control signal 13f _H supplied from BPF271,272.

The write clock signal formed as described above is supplied to the phase fine adjustment circuits 277 and 278, respectively. The phase fine adjustment circuits 277 and 278 enable fine adjustment of the phase of the write clock signal supplied by operating the operation unit 276, and the operator adjusts the video signal reproduced by the reproduction apparatus of the present embodiment. It is possible to operate the operation unit 276 while confirming the image on the monitor device, and finely adjust and optimize the phase of the write clock signal by the phase fine adjustment circuits 277 and 278.

The write clock signal output from the phase fine adjustment circuit 277 is supplied to A / D converters 227 and 238, and the phase fine adjustment circuit 27
The write clock signal output from 8 is the A / D converter 228,
248, and in each A / D converter, based on the supplied write clock signal, the supplied luminance signal, R
The digital luminance signal output from the A / D converters 227 and 228 after A / D conversion of the signal and the B signal is supplied to the memory 250, and the A / D
The digital R and B signals output from the converters 238 and 248 are supplied to the memory 251. Then, the memory control circuits 252 and 254 which are in the write control state according to the instruction from the system controller 275 operate based on the write clock signal output from the phase fine adjustment circuits 277 and 278, specify the write address to the memories 250 and 251 and supply them. The stored signals are stored.

As described above, the storage operation of the digital luminance signal for two frames obtained from the reproduction signals reproduced from the four recording tracks on the magnetic disk 286 into the memory 250 is completed, and the R signal and B for two frames are obtained. Signal memory 251
The completion of the storage operation for
When the system controller 275 detects this by counting the write clock signals output from the position fine adjustment circuits 277 and 278, the system controller 275 controls the memory control circuits 252 and 254.
In the read control state, and further instructs the interpolation calculation circuits 253 and 255 to start interpolation processing.

Hereinafter, the interpolation processing in the device of the present embodiment will be described. The positions of pixels on the screen corresponding to the digital luminance signal stored in the memory 250 are indicated by circles and circles in the right diagram of FIG. The positions on the screen of the pixels corresponding to the digital R signal and the B signal stored in the memory 251 are indicated by circles in the right diagrams of FIGS. 3B and 3C. Indicated by

FIGS. 3A, 3B, and 3C illustrate the interpolation processing of this embodiment.
In the data of the pixel at the position indicated by the mark, ○ and This is performed by an interpolation filter that performs interpolation processing using the data of The interpolation calculation circuits 253 and 255 instruct the memory control circuits 252 and 254 to read out the pixel data necessary for the interpolation processing by the above-described interpolation filter from the memories 250 and 251 and take in the interpolation calculation circuits 250 and 251. And the memory control circuits 252 and 254
The read addresses of the memories 250 and 251 are controlled in accordance with the instructions from 3,255, and the pixel data necessary for the interpolation processing are fetched into the interpolation calculation circuits 253 and 255. Each of the interpolation calculation circuits 253 and 255 uses the fetched pixel data as shown in FIG. A),
Interpolated pixel data corresponding to the marks (B) and (C) are formed and supplied to the memories 250 and 251.

At this time, the memory control circuits 252 and 254
In order to store the interpolated pixel data supplied to 0,251, it is designated in the write address memories 250,251, and the interpolated pixel data is stored in the memories 250,251.

As described above, by performing the interpolation processing, the memories 250 and 251
Holds pixel data of about 1200 × 1000 pixels per screen. Note that the color signal is
Since the information recorded in 256 is less than the luminance signal,
Although the interpolated pixel data formed by the interpolating process increases and the resolution cannot be increased, there is no particular problem because the deterioration of the image quality is not so noticeable on human visual characteristics.

After the interpolation processing on the memories 250 and 251 is completed as described above, the system controller 275 gives an instruction to the read clock signal generator 274 to supply the read clock signal to the memory control circuits 252 and 254, and the memory control circuits 252 and 254
Is synchronized with the supplied read clock signal,
Digital luminance signal and R signal held in 250 and 251
Each of the B signals is read and supplied to the signal forming circuit 256.

The signal forming circuit 256 is composed of a matrix circuit, a synchronizing signal adding circuit, etc., and forms various types of image signals using the supplied digital luminance signal, R signal, and B signal, and further generates a synchronizing signal. This is added and output.
In this embodiment, a digital output terminal 257 for outputting a digital video signal to a printer, a personal computer, or the like, a high-vision output terminal 259 for outputting an analog video signal conforming to the Hi-Vision standard, and an analog RGB signal are output. Terminal 261 for output, NTSC output terminal for outputting analog video signal according to NTSC standard
The operator selects an output mode of the video signal by the operation unit 276, and instructs the signal forming circuit 256 from the system controller 275 according to the output mode of the video signal selected by the operator. The signal forming circuit 256 converts the supplied digital luminance signal, R signal, and G signal into the output form of the selected video signal, adds a synchronizing signal, and outputs the signal in the form of an analog signal. In this case, digital / analog (D / A) converters 258, 260, and 262 convert the signals into analog signals, and then output from each output.

The operation of the reproducing unit of the electronic still video camera system shown in FIG. 5 when reproducing the video signal recorded on the magnetic disk based on the high-definition recording mode by the recording unit shown in FIG. However, when the recording unit reproduces the video signal recorded on the magnetic disk based on the normal recording mode (in a predetermined defocused state), the reproduction signal obtained from the magnetic heads 201 and 202 shown in FIG. 5 is processed. It is only necessary to operate only the circuit that applies. Since this operation is substantially the same as the case of reproducing the video signal recorded in the high-definition recording mode, detailed description is omitted, but the video signal recorded in the normal recording mode at the time of recording is appropriate. Then, a well-known interpolation process is performed and output, and a reproduced image in which aliasing interference is visually suppressed is obtained.

In the above case, the signal forming circuit 256 does not form an analog video signal conforming to the Hi-Vision standard,
A video signal is not output from the HDTV output terminal 259.

In addition, the switching of the reproduction process between the video signal recorded in the normal recording mode and the video signal recorded in the high-definition recording mode can be performed by operating the operation unit 276 and the system controller 275 in any recording mode. It is also possible to instruct whether or not to execute the reproduced processing, but a code for recording mode discrimination is set in an ID signal recorded together with a video signal at the time of recording, a recording mode discriminating circuit is provided in the reproducing unit, and a magnetic disk is provided. The recording mode discriminating code in the ID signal added to the reproduction signal reproduced from the 286 automatically determines which recording mode the reproduction signal was recorded in, and instructs the system controller 275 of the result to perform the reproduction processing. May be set.

As described above, in the system format of the electronic still video camera of the present embodiment, a high-definition video signal is recorded in a form conforming to the format of the electronic still video camera, and is reproduced. High-definition video signals can be restored without being affected by time axis fluctuations that occur during playback.Furthermore, video signals are recorded and played back in the normal recording mode while effectively preventing aliasing interference. It can also be.

Further, in the above-described embodiment, an apparatus using four magnetic heads has been described as an example. However, the present invention is not limited to this, and two or one magnetic head is sequentially used during recording or reproducing operation. By moving it, it can be applied to an apparatus that records or reproduces an image signal on a magnetic disk, and the imaging unit is not limited to a three-plate type using three imaging elements. The present invention can be applied to a single-panel type using one imaging element or a two-panel type using two imaging elements.

〔The invention's effect〕

As described above, according to the present invention, the video signal based on the conventional format without compromising the image quality of the reproduced image and the luminance component as well as the color component while maintaining compatibility with this format are more sufficient than before. Thus, it is possible to provide an image signal recording apparatus capable of recording a high-quality image signal on a recording medium.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a recording unit of an electronic still video camera system to which the present invention is applied, as one embodiment of the present invention. FIG. 2 is a diagram showing a configuration of a color filter provided on an imaging surface of an imaging element of a recording unit of the electronic still video camera system shown in FIG. FIGS. 3A, 3B and 3C show the arrangement and reproduction of pixels corresponding to the video signal recorded on the magnetic disk in the high definition recording mode in the electronic still video camera system of this embodiment. FIG. 3 is a diagram illustrating a relationship in arrangement of pixels to be interpolated. FIGS. 4A, 4B, 4C, and 4D are diagrams showing the arrangement of color signals in a high-definition image. FIG. 5 is a diagram showing a schematic configuration of a reproducing unit in the electronic still video camera system of the present embodiment. FIG. 6 is a diagram showing a configuration of a color filter in another embodiment, FIG. 7 is a diagram showing a first configuration example of the lens driving circuit of FIG. 1, and FIGS. 8 (a) to (c) are FIG. 8 (d) shows a relationship between MTF and spatial frequency at the time of focusing and defocusing, and FIG. 9 shows a second configuration example of the lens driving circuit of FIG. FIG. 101: Optical lens, 151: System controller, 152: Operation unit, 170: Lens driving circuit, 801,1002: Adder, 802: Defocus data generator, 1000: ROM.

Claims (1)

(57) [Claims] 1. An apparatus for recording an image signal on a recording medium based on any one of a plurality of different recording modes, comprising: optical means; A recording unit that converts an image formed into an image signal based on one of the plurality of recording modes and records the image signal; and at least one of the plurality of recording modes, An image signal recording apparatus, comprising: a control unit that controls the optical unit so as to give a defocused image to the recording unit.