JPH04213981A - Still video device - Google Patents

Abstract

PURPOSE:To obtain images faithful to an object in spite of the presence of a drop-out in the tracks of a magnetic disk and to reproduce the same images even if the image signals on the tracks are erased by mistake. CONSTITUTION:Two magnetic heads A, B are provided. The image signals synthesized with brightness signals and color signals for one still picture are simultaneously recorded in the two tracks of the magnetic disk D by the magnetic heads A, B. ID data including prescribed track numbers are recorded in the respective tracks. Then, the same image signals are recorded in the two tracks and, therefore, even if there a defect in one or even if the one is erased, the desired image is obtd. by reproducing the other image signal.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still video apparatus, and more particularly to an improvement in a structure for recording image signals on a recording medium such as a magnetic disk.

0002

2. Description of the Related Art Recording media used in still video devices are usually magnetic disks, and recording and reproduction of images on the magnetic disks include field recording, which uses only one track for one screen, and field recording, which uses two tracks for one screen. There are two methods of frame recording used. At this time, if there is, for example, uneven coating of magnetic powder on the surface of the magnetic disk, dropouts will occur, and the image corresponding to these areas will be disturbed. Therefore, in order to prevent this, interpolation of image signals is performed.

0003

However, even with such interpolation, it is not possible to completely correct the image, and therefore, if dropouts or the like occur, a faithful image of the subject cannot be obtained. Furthermore, in field recording, when attempting to erase one track's worth of image signals, if the signal of another track is erased by mistake, it is impossible to restore the erased signal. An object of the present invention is to provide a still video device that can obtain an image that is faithful to the subject with higher reliability, and that can obtain the same image again even if the image signal is erased by mistake. .

0004

[Means for Solving the Problems] The present invention has been made to solve the conventional problems as described above, and includes a signal generating means for generating an image signal by combining a luminance signal and a color signal, and a single The present invention is characterized by comprising a signal recording means for recording the image signals for still images on a plurality of tracks of a recording medium.

[0005]

EXAMPLES The present invention will be explained below with reference to illustrated examples. FIG. 1 shows a still video apparatus according to an embodiment of the present invention. This still video device uses a magnetic disk D as a recording medium. The system control circuit 10 is a microcomputer that controls the entire device, and this system control circuit 1
0, the photographed image is recorded on the magnetic disk D, and the image signal etc. on the magnetic disk D is reproduced.

The magnetic disk D is rotated by a spindle motor 11, and the spindle motor 11 is driven and controlled by a motor drive circuit 12. The spindle motor 11 outputs one PG pulse and a predetermined number of FG pulses for each rotation of the magnetic disk D. The system control circuit 10 controls the rotation of the spindle motor 11 based on these pulse signals, and controls the rotation of the magnetic disk D.
rotate at a predetermined speed. Two magnetic heads A and B are used for recording and reproducing image signals etc. on the magnetic disk D.
are provided, and the positions of these magnetic heads A and B are controlled to predetermined tracks on the magnetic disk D by a tracking drive circuit 13. The tracking drive circuit 13 is controlled by the system control circuit 10.

An operating section 14 is connected to the system control circuit 10 . The operation section 14 includes a changeover switch 14a, a selection switch 14b, a head feed switch 14c, and a release switch 14d. The changeover switch 14a is a switch for setting either recording or reproduction of image signals, etc. on the magnetic disk D. The selection switch 14b is a switch for selecting one of 1-track field mode, 2-track field mode, and frame recording mode. Here, the 1-track field mode refers to a mode in which recording is performed by magnetic heads A or B, and the 2-track field mode refers to a mode in which magnetic heads A and B record the same image signal on two tracks. The head feed switch 14c is a switch for moving the magnetic head A or B to a predetermined track position during reproduction. Incidentally, during recording, the magnetic heads A and B are configured to be automatically positioned at vacant track positions. Release switch 1
4d is a switch for photographing with a still video device.

A configuration for recording image signals on the magnetic disk D will be explained. The imaging unit 20 is a solid-state imaging device (
It is controlled by the system control circuit 10, and forms an image on the CCD, and also separates this image into a luminance signal and a color signal and outputs the same. The luminance signal and chrominance signal are transmitted to a luminance signal FM modulation circuit 21 and a chrominance signal FM modulation circuit 21, respectively.
The modulation circuit 22 performs FM modulation. Each FM modulation circuit 2
1, 22 are connected to the adder 23 and therefore F
The M-modulated luminance signal and color signal are combined with each other by an adder 23, thereby generating an image signal corresponding to one still image.

Adders 24 and 25 are connected to the adder 23, and the same image signal is guided to these adders 24 and 25. The adders 24 and 25 include a DPSK modulation circuit 2.
6 and 27 are connected, respectively. DPSK modulation circuit 26
, 27 generate a DPSK signal of ID data consisting of the track number of the magnetic disk D, the date of shooting, etc., and the carrier, that is, the carrier wave output from the carrier generation circuit 28, is output from the system control circuit 10. DPSK modulation is performed based on the ID data. The carrier generation circuit 28 generates carriers based on the pulse signal output from the pulse generation circuit 29.

ID data will now be explained with reference to FIG. Note that "H" in FIG. 2 indicates a horizontal scanning period. The structure of this ID data itself is the same as that used in conventionally known still video devices, but in this embodiment, when recording in the 2-track field mode, the track number N of each ID data corresponding to two image signals is , are controlled to correspond to each track. For example, when recording an image on the first and second tracks in 2-track field mode, the ID data of the first track contains the track number indicating the first track, and the ID data of the second track contains the track number indicating the first track. A track number indicating each is recorded. That is, the track number N is determined by the system control circuit 10 to be that of the corresponding track, and based on the ID data including this predetermined track number N, the carrier output from the carrier generation circuit 10 is determined by the DPSK modulation circuit 26, The signal is DPSK-modulated by 27 and guided to adders 24 and 25. In the two-track field mode, two identical image signals are generated for one still image, and each image signal is superimposed with ID data corresponding to the track in which these signals are recorded.

First and second recording gates 31 and 32 are connected to each adder 24 and 25, respectively. The first recording gate 31 is connected to the recording side terminal R of the switch 34 via the recording amplifier 33, and the second recording gate 32 is connected to the recording side terminal R of the switch 36 via the recording amplifier 35. The first and second recording gates 31 and 32 are controlled to open and close by a gate control circuit 40, and are closed by a high signal (command signals RGA' and RGB' to be described later).
Open by low signal. As will be described later, in the 2-track field mode, the first and second recording gates 3
1 and 32 are closed together, and as a result, 2 of the magnetic disk D
The same image signal is recorded on two tracks. switch 3
4 and 36 are switched and controlled by the system control circuit 10,
When recording an image signal or the like on the magnetic disk D, it is switched to the recording side position R, and when reproducing an image signal or the like on the magnetic disk D, it is switched to the reproduction side position P.

The gate control circuit 40 includes an AND gate 41
, 42 and OR gates 43 and 44. These gates 41, 42, 43, and 44 receive a command signal RGA from the system control circuit 10 for causing the magnetic head A to record on the magnetic disk D, and a command signal RGA for causing the magnetic head B to record on the magnetic disk D. A command signal RGB and a command signal 2FD for recording on the magnetic disk D by the magnetic heads A and B (ie, 2-track field mode) are input. That is, the command signal RGA is input to the first input terminal of the AND gate 41,
A command signal 2FD is input to the second input terminal. Further, the command signal RGB is input to the first input terminal of the AND gate 42, and the command signal 2FD is input to the second input terminal. The output terminal of the AND gate 41 is connected to the first input terminal of the OR gate 44, and the command signal RGB is input to the second input terminal of the OR gate 44. The output terminal of the AND gate 42 is connected to the first input terminal of the OR gate 43, and the command signal RGA is input to the second input terminal of the OR gate 43. The output terminal of the OR gate 43 is the first recording gate 31
The output terminal of the OR gate 44 is connected to the second recording gate 32. Therefore, command signals RGA' and RGB' are guided to the first and second recording gates 31 and 32 from OR gates 43 and 44, respectively.
The recording gates 31 and 32 receive these command signals RGA' and R
Opening/closing is controlled by GB'.

Recording of still image signals and the like onto the magnetic disk D will be explained with reference to FIGS. 1 and 3. When recording on the magnetic disk D, the changeover switch 14 of the operation unit 14
a has been switched to the recording side position. On the other hand, as indicated by symbol E, a PG pulse is periodically output every rotation of the magnetic disk D. Now, when the selection switch 14b is set to the 1-track field mode, the command signal I indicating this mode is output, and the command signal J for the 2-track field mode is not output. Therefore, a low signal is input to the second input terminals of the AND gates 41 and 42 of the gate control circuit 40, and the AND gates 41 and 42
outputs a low signal. On the other hand, command signals RGA and RGB are input to second input terminals of OR gates 43 and 44, respectively. Therefore, OR gates 43 and 44 output signals corresponding to command signals RGA and RGB regardless of the low signals output from AND gates 41 and 42. That is, in the case of 1 track field mode, OR gate 4
3, a command signal R input to the gate control circuit 40
A command signal RGA' corresponding to GA is output, and a command signal RGB' corresponding to command signal RGB is output from the OR gate 44. The magnetic head used in the 1-track field mode is, for example, magnetic head A.
It is stipulated in In this case, the system control circuit 10 outputs the command signal RGA, and therefore the gate control circuit 40 outputs the command signal RGA'. As shown by the symbol L, this command signal RGA' is generated when the release switch 14d is pressed and the release signal M is output.
It is output during one cycle of the G pulse. As a result, the first recording gate 31 is closed while the magnetic disk D rotates once, and the magnetic head A performs recording on the magnetic disk D.

Next, a case will be explained in which the selection switch 14b is set to the 2-track field mode. In this case, a command signal J indicating this mode, that is, a high signal, is output from the system control circuit 10, and the AND gate 41
, 42 receives this high signal. Therefore, a high signal is output from the output terminals of the AND gates 41 and 42 to which the command signal RGA or RGB is input. That is, if the command signal RGA is input to the gate control circuit 40, the OR gate 43 not only outputs the command signal RGA', but also the AND gate 41 outputs a high signal, so the OR gate 44 outputs the command signal RG.
Output B'. Furthermore, if the command signal RGB is input to the gate control circuit 40, the AND gate 42 outputs a high signal, so in this case as well, the OR gate 43,
44 output command signals RGA' and RGB', respectively. In the case of the 2-track field mode, when the gate control circuit 40 receives the command signal RGA or RGB, it outputs the command signal R from the OR gates 43 and 44, respectively.
Outputs GA' and RGB'. Therefore, along with the output of the release signal M, the command signals RGA' and RGB' are simultaneously outputted as shown by symbols S and T in synchronization with the output of the PG pulse, thereby causing the first and second recording gates 31, 32 is closed, and magnetic heads A and B perform recording on magnetic disk D.

In the frame recording mode, by setting the selection switch 14b to this mode position,
The system control circuit 10 outputs a command signal K for this mode, but does not output a command signal J for the 2-track field mode. Therefore, when the gate control circuit 40 receives the command signals RGA and RGB from the system control circuit 10, it outputs the command signals RGA and RGB in synchronization with these signals.
', RGB' is output. As is conventionally known, the frame recording mode is a mode in which one image is divided into two fields and recorded by interlaced scanning. In this mode, the system control circuit 10 outputs a command signal RGA to record the magnetic disk D. magnetic head A for a given track
After recording is performed, a command signal RGB is output to cause the magnetic head B to record on the next track. That is, after the gate control circuit 40 outputs the command signal RGA' during one rotation of the magnetic disk D, as shown by symbols U and V,
The command signal RGB' is output during the next rotation of the magnetic disk D. Therefore, while the magnetic disk D rotates once,
The first recording gate 31 is closed and the magnetic head A performs recording on the magnetic disk D. Then, while the magnetic disk D rotates once, the second recording gate 32 is closed and the magnetic head B performs recording. Recording on the magnetic disk D is performed by this.

Next, a configuration for reproducing image signals recorded on the magnetic disk D will be explained. When reproducing image signals etc. on the magnetic disk D, the switches 34 and 36 are switched to the reproduction side position P. The reproduction side terminal P of the switch 34 is connected to the adder 52 via the head amplifier 51, and the reproduction side terminal P of the switch 36 is connected to the adder 52 via the head amplifier 53 and the switch 54. The adder 52 includes, for example, two resistors 501 and 5 as shown in FIG.
It is configured by connecting 02. The opening and closing of the switch 54 is controlled by a command signal 2FD output from the system control circuit 10 and indicating the 2-track field mode. The adder 52 is an automatic gain control (AGC) amplifier 55
is connected to the switch 56 via the head amplifier 5.
3 is connected to a switch 56 via an AGC amplifier 57. This switch 56 is switched by a head switching signal output from the system control circuit 10, and this head switching signal is a signal indicating which magnetic heads A and B are used to reproduce signals on the magnetic disk D.

The output end of the switch 56 is connected to the high-pass filter 6.
1 to a luminance signal FM demodulation circuit 62, and this FM demodulation circuit 62 is connected to an encoder 71 and a synchronization signal separation circuit 72 via a skew correction circuit 63. The skew correction circuit 63 is a circuit that performs correction to remove distortion on the screen in the case of field recording. The synchronization signal separation circuit 72 separates the horizontal synchronization signal HSYN from the luminance signal.
The horizontal synchronizing signal HSYNC and the vertical synchronizing signal VSYNC are input to the system control circuit 10 and used for reading ID data, for example. Also switch 56
The output terminal of is connected to a color signal FM demodulation circuit 65 via a low-pass filter 64, and this FM demodulation circuit 65 is connected to an encoder 71 via a skew correction circuit 66 and a synchronization circuit 67. The synchronization circuit 67 outputs a color difference signal (R-
This is a circuit for simultaneously outputting signals (Y, B-Y) for each horizontal scanning line. Therefore, the encoder 71 receives a luminance signal and a color difference signal corresponding to a predetermined horizontal scanning line.
A video signal is generated based on these. Further, the output terminal of the switch 56 is connected to the DPS via a bandpass filter 68.
This DPSK demodulation circuit 69 is connected to the K demodulation circuit 69.
is connected to the system control circuit 10. Therefore, ID data is input to the system control circuit 10 via the DPSK demodulation circuit 69.

Between the adder 52 and the AGC amplifier 55,
An envelope detection circuit 73 is connected. The envelope detection circuit 73 performs envelope detection on the reproduced signal, and the envelope-detected output signal is input to the system control circuit 10. The system control circuit 10 controls the magnetic head A so that the voltage of this envelope detection output signal is maximized.
, B are finely adjusted, thereby obtaining an optimal reproduction signal.

The reproduction of image signals of still images on the magnetic disk D will be explained with reference to FIGS. 1 and 3. During playback, the selector switch 14a of the operation section 14 is switched to the playback side position. As a result, the switches 34 and 36 are respectively switched to the reproduction side terminal P. Here, the magnetic heads A and B are set at predetermined track positions on the magnetic disk D by operating the head feed switch 14c.

When the 1-track field mode is selected by the selection switch 14b, the switch 54 is opened, and as shown in FIG. Since the signal is output from the system control circuit 10, the switch 56 is switched to a position corresponding to predetermined magnetic heads A and B (for example, to the magnetic head A side). Therefore, in this case, the signal read by the magnetic head A passes through the switch 34, the head amplifier 51, the adder 52, the AGC amplifier 55, the switch 56, and the luminance signal FM demodulation circuit 6.
2. The color signal is subjected to FM demodulation or DPSK demodulation by the FM demodulation circuit 65 and the DPSK demodulation circuit 69. Note that at this time, the signals read by the magnetic head B are not subjected to FM demodulation or PDSK demodulation because the switches 54 and 56 are open. In this way, the image signal read by one of the magnetic heads A or B is converted into a video signal and output from the encoder 71, and the corresponding ID data is input to the system control circuit 10 and decoded.

On the other hand, the selection switch 14b selects 2
When the track field mode is selected, the switch 54 is closed, and the switch 56 is set to the magnetic head A side by the command signal X. Therefore, the reproduced signal read by the magnetic head A is transmitted via the switch 34 and the amplifier 51, and the reproduced signal read by the magnetic head B is transmitted via the switch 36 and the amplifier 51.
3 and a switch 54 to an adder 52, where they are mutually added. The added reproduction signal passes through an amplifier 55 and a switch 56, and is subjected to FM demodulation or DPSK demodulation by FM demodulation circuits 62, 65 and a DPSK demodulation circuit 69. The reproduced signals read by the magnetic heads A and B are ideally the same, but in reality each contains noise. Of these reproduced signals, the originally necessary signal components representing images etc. have the same phase, so
Assuming that the resistance values of the resistors 501 and 502 are the same, the voltage of the signal output from the adder 52 is the arithmetic average of each reproduced signal. On the other hand, since the noise contained in each reproduced signal has a mutually different phase, the noise voltage output from the adder 52 is determined by calculating the sum of the squares of the noise voltages of the two reproduced signals, and then calculating the square root of this sum. It is divided by 2. In other words, the voltage of the component representing an image or the like in the reproduced signal is not changed by the adder 52, but the noise is increased by about 0.7 times. Therefore, the C/N ratio (carrier-to-noise ratio) of the reproduced signal is approximately 1.4 due to the action of the adder 52.
It becomes twice as big.

When the frame recording mode is selected by the selection switch 14b, the switch 54 is opened and a command signal Y for operating the magnetic head B is sent.
and a command signal Z for operating the magnetic head A are alternately outputted from the system control circuit 10 in synchronization with the PG pulse. Therefore, the switches 56 are alternately set on the sides of the magnetic heads A and B, whereby an image signal corresponding to one image is generated and output from the encoder 71 as a video signal.

As described above, in this embodiment, the magnetic disk D
It is configured so that the same image signal can be recorded on two tracks. Therefore, for example, if a dropout occurs in the image signal of one track when playing back in 1-track field mode, you can move magnetic head A to the other track or play back with magnetic head B. By switching to , it is possible to reproduce the image signal of the other track and reproduce an image without defects. Such recording on two tracks is particularly effective when performed for important images such as photographic evidence. Furthermore, according to this embodiment,
Even if you accidentally erase the signal on one track, the same signal is stored on the other track, so you can switch the magnetic head to the other track in the same way as described above. Alternatively, by switching the magnetic heads, it is possible to reproduce a desired image signal.

Note that in the above embodiment, the magnetic head A
, B to act on the first and second recording gates 31
, 32, command signals RGA', RGB'
is generated by the gate control circuit 40, but instead of this, it may be configured to be generated by software in the system control circuit 10.

FIG. 5 shows a second embodiment. This embodiment differs from the circuit shown in FIG. 1 in that the magnetic head A is
Only one is provided. That is, in this embodiment, one magnetic head A records image signals and the like on two tracks of a magnetic disk D. For this reason, the imaging unit 2
Frame memories 82 and 86 are provided for storing one field worth of signals output from 0.

A/D converters 81 and 85 are connected to the image pickup section 20, and the luminance signal and color signal are converted to A/D converters 81 and 85, respectively.
The data is converted into D and stored in frame memories 82 and 86. The luminance signal and color signal stored in the frame memories 82 and 86 are converted into D/A converters 83 and 87, respectively.
After being A-converted, the signals are FM-modulated by a luminance signal FM modulation circuit 84 and a color signal FM modulation circuit 88, and are combined by an adder 89 to form an image signal. A/D converter 81, 8
5. Frame memory 82, 86, D/A converter 83, 8
7 is controlled by a system control circuit 10. The DPSK signal of the ID data is led to an adder 89 and superimposed on the image signal. Since only one magnetic head A is provided in the DPSK modulation circuit 26, one
Only one can be provided. Also, only one adder 8 is provided in order to simultaneously perform the synthesis of the luminance signal and the color signal and the superposition of the ID data. Therefore, only one recording gate 31 and only one switch 34 are provided. Note that the adder 52 (FIG. 1) for superimposing reproduced signals is not provided. The other configurations are basically the same as the embodiment shown in FIG.

In this embodiment, one field's worth of signals is temporarily stored in the frame memories 82 and 86, and recorded on a predetermined track by the magnetic head A. After this recording is completed, the magnetic head A is moved to the next track, and then the same signals stored in the frame memories 82 and 86 are recorded on this track. However, the ID data output from the system control circuit 10 at this time includes a predetermined track number, and is superimposed on the image signal in the adder 89. This embodiment also provides the same effects as the embodiment shown in FIG. In each of the above embodiments, the magnetic disk D was used as a recording medium, but the present invention is not limited to this, and can also be applied to a still video device using an IC card or the like as a recording medium, for example. .

[0028]

[Effects of the Invention] As described above, according to the present invention, it is possible to obtain an image that is faithful to the subject with higher certainty, and even if the image signal is erased by mistake, it is possible to obtain the same image again. You can get the effect of

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a still video device according to an embodiment of the present invention.

FIG. 2 is a diagram showing ID data.

FIG. 3 is a timing chart showing operations for recording and reproducing image signals.

FIG. 4 is a circuit diagram showing an adder.

FIG. 5 is a circuit diagram showing another embodiment of the present invention.

[Explanation of symbols]

A, B Magnetic head D Magnetic disk

Claims (4)

[Claims] 1. A signal generating means for generating an image signal by combining a luminance signal and a color signal, and a signal recording means for simultaneously recording the image signal for one still image on a plurality of tracks of a recording medium. A still video device characterized by: 2. A still video apparatus according to claim 1, wherein said signal recording means has a plurality of magnetic heads for recording said image signal on a recording medium. 3. The still video apparatus according to claim 2, further comprising ID data recording means for recording ID data corresponding to each track on the track. 4. The still video apparatus according to claim 1, further comprising a memory for storing said image signal.