JPH04249992A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce a still picture by superimposing the still picture signal converted into a digital signal within a vertical blanking period of a moving picture. CONSTITUTION:The device is so constituted that a color signal of a moving picture is subjected to frequency conversion and the result is multiplexed onto a frequency modulation luminance signal and recorded and reproduced, and a video signal is converted into a digital signal and subjected to band compression to generate a still picture, and the still picture data is multiplexed in time division for plural horizontal scanning periods within a vertical blanking period of the moving picture luminance signal and recorded and reproduced. The still picture of high picture quality is recorded and reproduced without giving any effect onto a moving picture and an audio signal recorded simultaneously.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing apparatus for recording and reproducing still images.

0002

2. Description of the Related Art In a helical scan type magnetic recording and reproducing apparatus, the following methods are available as means for recording and reproducing still images.

[0003] ■ When playing back a magnetic tape on which a normal moving image is recorded while forming one recording track per field, the running of the magnetic tape is stopped and the same part of the magnetic tape is continuously played back. What I did to get the image.

[0004] A frame memory is built into the video camera section, and by operating a trigger button, one frame of video signal stored in the frame memory is repeatedly read out for a certain period of time and recorded on a magnetic tape at a constant tape running speed. This device can obtain a still image by reproducing the recorded portion of the still image at a constant tape running speed.

[0005] ■ When playing back a magnetic tape on which normal moving images are recorded while forming one recording track per field, the reproduced video signal while running at a constant speed is stored in a frame memory, and one recording track is recorded from the frame memory. A still image is obtained by repeatedly reading out the frame video signal.

[0006]

[Problems to be Solved by the Invention] In a helical scan type VTR, during still playback as shown in the above-mentioned conventional technique (2), which is generally performed by stopping the running of the magnetic tape, the scanning locus of the playback head on the magnetic tape is The angle of is different from the angle of the recording track. As a result, the track pattern cannot be accurately scanned, and there are portions where the level of the reproduced signal decreases, resulting in a deterioration of the S/N ratio of the reproduced video signal. In addition, in the conventional technique (2) described above, when recording still images, recording of moving images is temporarily interrupted, and as a result, moving image recording portions and still image recording portions are mixed on the recorded magnetic tape. This causes a problem in that information about the moving image is lost and the image becomes unsightly during playback. In the conventional technique (2) described above, a still image is obtained from a video signal recorded as a moving image using a frame memory, so there is no problem with the deterioration of the S/N ratio or the mixing of recorded parts of moving images and recorded still images. Although this does not occur, there is a problem in that only videos recorded as moving images can be obtained as still images, and it is not possible to record and reproduce still images that are different from moving images.

[0007]Furthermore, in all of the conventional techniques (1), (2), and (3), the luminance signal is frequency-modulated and the color signal is converted to a lower frequency band than the frequency-modulated luminance signal to generate the frequency-modulated luminance signal. It is recorded multiplexed. When recording and playing back using this so-called color-under method, the image quality is sufficient for viewing the playback signal as a moving image on a television monitor, but it is not possible to print still images recorded and played back using the color-under method on a video printer. When viewing, there is a particular problem that the color signal band is not sufficient and the color resolution is insufficient.

[0008]

[Means for Solving the Problems] The present invention has been made in order to solve the above-mentioned problems.The present invention frequency-modulates a luminance signal contained in a video signal to produce a frequency-modulated luminance signal, and converts a chrominance signal into a frequency-modulated luminance signal. A magnetic recording and reproducing device configured to convert a frequency modulated luminance signal to a lower frequency band to obtain a low frequency converted color signal, and multiplex the frequency modulated luminance signal and the low frequency converted color signal for recording and reproduction. , converting the video signal or a video signal different from the video signal into a digital signal and compressing the band to generate a still image, and converting this still image into a plurality of horizontal scanning periods within a vertical scanning retrace period of the video signal. A magnetic recording and reproducing device that performs recording and reproducing in a time-divisionally superimposed manner;

[0009] The luminance signal included in the video signal is frequency-modulated to produce a frequency-modulated luminance signal, the color signal is converted to a frequency band lower than the frequency-modulated luminance signal to produce a low-band-converted color signal, and the frequency-modulated luminance signal and A magnetic recording and reproducing device configured to record and reproduce the low frequency converted color signal by multiplexing the same with the video signal, the magnetic recording and reproducing device converting the video signal or another video signal different from the video signal into a digital signal, and converting the video signal into a digital signal. Alternatively, if a motion of the other video signal is detected, one field of one frame is band-compressed to generate a still image, and if the motion is not detected, one frame is double scan-converted and the band is compressed. To provide a magnetic recording and reproducing device which compresses a still image to generate a still image, and records and reproduces the still image by time-divisionally superimposing it on a plurality of horizontal scanning periods within a vertical scanning blanking period of the video signal. It is something.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings shown in FIGS. 1 and 2. FIG. 1 shows a detailed recording configuration of the present invention when applied to a camera-integrated VTR. In the figure, a CCD 10 is an image sensor that converts an optical image that has passed through an imaging lens (not shown) into an electrical signal, and a signal processing circuit 1 that processes an output signal from the CCD 10.
Together with 2, it constitutes a video camera. The signal processing circuit 12 performs gamma correction and color signal encoding. A luminance signal output 16 of the signal processing circuit 12 is connected to one input terminal of an adder 24 and an analog-to-digital converter (hereinafter referred to as an A/D converter) 32. The other input terminal of the adder 24 is supplied with a digital still image, which will be described later. The frequency modulator 26 frequency-modulates the luminance signal on which the digital still image is superimposed from the adder 24 and supplies it to the other input terminal of the adder 28 as a frequency-modulated luminance signal.

On the other hand, the carrier color signal output 14 of the signal processing circuit 12 is connected to a low frequency converter 22. The low-pass converter 22 converts the carrier color signal into a frequency band lower than that of the frequency-modulated luminance signal and supplies it as a low-pass converted color signal to the other input terminal of the adder 28, thereby converting the frequency-modulated luminance signal and the low-pass converted color signal. The signals are multiplexed and recorded on a magnetic tape (not shown) by the magnetic head 30.

The luminance signal from the luminance signal output 16 of the signal processing circuit 12 is also supplied to the A/D converter 32, where the 1
Sampling is performed at 3.5 MHz and the number of quantization bits is 8 bits. The luminance signal converted into a digital signal by the A/D converter 32 is stored in the frame memory 34 or 36. Since data cannot be written while data is being read from the frame memory, in order to make it possible to read one frame of data while reading data,
Two frame memories are provided. Therefore, unless there is a configuration in which data is written during reading, the frame memory 36 is not required.

Data in the frame memory that is being read is supplied to a mode selection circuit 40 and a motion detection circuit 50 via a switch 38. A motion detection circuit 50 detects motion of the image in the frame memory 34 or 36. The mode signal generation circuit 52 generates a mode signal in response to this motion detection signal and a mode instruction signal inputted to the terminal 54 indicating, for example, standard or automatic by switch operation. The mode selection circuit 40 generates, selects, and outputs a predetermined still image according to the mode signal. The detailed configuration and operation of the mode selection circuit will be described later. The frequency band of the luminance signal of the video signal is approximately 5 MHz, and if this is 8-bit quantized using a 13.5 MHz sampling clock, the amount of data will be enormous. In order to reduce the amount of data and perform high-density recording, the compression circuit 42 reduces the number of bits of the still image from the mode selection circuit, that is, compresses the band in which the still image is recorded. As a band compression technique, discrete cosine transform (DCT transform), Hadamard transform, Huffman variable length code, etc. can be used, and data compression of up to about 1/40 is possible.

On the other hand, the RY signal and B-
The Y signal is sent to the R-Y signal processing circuit 60 and the B-Y signal processing circuit 60, respectively.
The signal is supplied to the signal processing circuit 62. These color signal processing circuits include the A/D converter 32 of the luminance signal processing circuit 46;
The configuration is similar to that of the frame memories 32 and 34, the switch 38, the mode selection circuit 40, and the compression circuit 42, so a description thereof will be omitted. However, the sampling frequency is 6.75
The difference is that the frequency is MHz, and that the mode signal is obtained from the output of the mode signal generator 52.

A still image of the luminance signal output from the compression circuit 42 and a color signal (RY signal, B-Y signal) output from the compression circuits of the RY signal processing circuit 60 and the BY signal processing circuit 62 The still images of the signal) are both input to the encoder 44, where an error check code is added, data interleave, etc. are performed. The recording data from the encoder 44 is supplied to the other input terminal of the adder 24 in accordance with a gate signal to be described later, and is therefore multiplexed with the luminance signal from the signal processing circuit 12 and recorded on the magnetic tape.

FIG. 2 is a diagram showing the timing relationships among gate signals, video signals, and still image data. FIG. 3A is a diagram showing the vertical scanning blanking period portion of the luminance signal output signal of the signal processing circuit 12. Counts the number of horizontal synchronization signals from the vertical synchronization signals and generates a gate signal (B in the same figure) that becomes high level in the horizontal scanning sections from the 12th to the 21st and from the 274th to the 283rd. The signal is supplied to the encoder 44.

During the horizontal scanning period (hereinafter also referred to as line) when the gate signal is at a high level, the encoder 44 adds an error check code to the still image data and intermittently sends the still image data to the other input terminal of the adder 24. Output the data (C in the same figure). As a result, the output signal of the adder 24 is such that still image data is superimposed in the horizontal scanning period from the 12th to the 21st and from the 274th to the 283rd of the vertical scanning retrace period of the luminance signal, as shown in FIG. 2D. The signal becomes
This is frequency modulated, multiplexed with the low frequency conversion color signal, and recorded on a magnetic tape.

[0018] The sampling frequency of the luminance signal is set to 13.5.
MHz, the number of effective samples in the image part of one horizontal scanning period is 720 samples, the number of effective horizontal scanning periods in the image part of one frame is 488, and the number of quantization bits of the luminance signal is 8 bits. The number of data per frame of the luminance signal to be stored is approximately 2.8 Mbits. For color signals, the sampling frequency is 6.7
Although the frequency is 5 MHz, since sampling is performed for two color difference signals, the number of color signal data per frame stored in the frame memory is approximately 2.8 Mbits. Therefore, the total number of data in one frame of video signal is approximately 5.6 Mbits. When a frame still image is selected by the mode selection circuit, data of 5.6 Mbits per frame is compressed to, for example, 1/16 by the compression circuit 52, so that the number of data per frame is 351 Kbits.

The number of data superimposed on one line of the video signal is 38 bytes, that is, 304 bits, of which 6 bytes are used for control codes, error check codes, etc., and 32 bytes are used for still images. Of these, the luminance signal uses 16 bytes, the RY signal uses 8 bytes, and the BY signal uses 8 bytes. Since data is superimposed on 10 lines in one field, 2560-bit still image data is recorded. Therefore, one frame of still image of 351 Kbits can be recorded in 138 fields, that is, about 2.3 seconds. At this time, 304 bits of data are converted to NRZ in a period of approximately 50 μs in one line of the luminance signal.
The data is superimposed as a signal, and the maximum repetition frequency of the data portion is approximately 3 MHz, and the bit period is approximately 6 Mbit/sec. Therefore, since the frequency band of the luminance signal in the data superimposed portion is approximately 3 MHz, a VTR capable of recording and reproducing video signals with a band of 5 MHz can sufficiently record and reproduce still image data. A clock signal for this digital processing can be easily generated by multiplying the horizontal synchronization frequency by 386 using a PLL.

As described above, since one frame of still images is intermittently recorded over a period of 138 fields, it is necessary to add a frame identification signal so that the data at the beginning of one frame can be identified during playback. This can be made into a frame identification signal using the control code described above. That is, a control code including a frame identification signal is placed and recorded at the beginning of the first line of data in one frame of still image data, and this is detected during playback to detect the start of one frame of still image data. do.

The mode signal generating circuit 52 in FIG.
When the mode instruction signal indicates standard, the mode signal M1 is output; when the mode instruction signal indicates automatic and the motion detection circuit 50 indicates there is movement, the mode signal M2 is output; when the mode instruction signal indicates automatic and the motion detection circuit 50 When indicates no movement, a mode signal M3 is generated. The mode selection circuit 46 outputs one frame of still image data as a frame still image mode when the mode signal M1 is input, and outputs one field of still image data as a field still image mode when the mode signal M2 is input. When M2 is input, the frame double scan still image mode is 1, which is double scan converted as described below.
Frame still image data is selected and supplied to the compression circuit 52.

FIG. 3 is a diagram for explaining double scanning conversion. In the figure, a delay circuit 100 delays data from a frame memory 34 or 36 by one horizontal scanning period, and an adder 102 and an attenuator 104
Line interpolation is performed by averaging the data before and after the horizontal scanning period, and the resulting data is supplied to one terminal of the switch 106. Data read from the frame memory 34 or 36 is directly supplied to the other terminal. By alternately selecting and outputting the interpolated signal and the direct signal line by line, double-scan converted data can be obtained. Therefore, the number of data is twice the normal number of data.

The mode signal M1, M2, or M3 is also supplied to the compression circuit 42, the encoder 56, and each compression circuit (not shown) of the R-Y and B-Y signal processing circuits, and is applied to each mode. Corresponding signal processing is performed. As a result, when in frame still image mode, it takes about 2.3 seconds (138 fields) as mentioned above.
One still image is recorded in approximately 1.2 seconds (69 fields) in field still image mode, and approximately 4.6 seconds (276 fields) in frame double scan still image mode. field) to record one still image. These mode signals are inserted into the control code by the encoder 44 and recorded on the magnetic tape together with the still image data. In this way, when there is movement in a still image, a large number of still images are recorded and played back using a small amount of data, and when there is no movement in the still image, high-quality still images are recorded and played back. It is possible to automatically record and play back high-quality still images with an appropriate amount of data.

Next, the configuration for reproduction will be explained using FIG. 4. Video signals of moving images and still images recorded on the magnetic tape are reproduced by the magnetic head 30. LPF
302 separates the low frequency converted color signal from the reproduced signal, and a frequency converter 304 performs frequency conversion opposite to that during recording.
A 3.58 MHz carrier color signal is output from the terminal 306. Further, a high-frequency component is separated from the reproduced signal by an HPF 308 to obtain a frequency-converted luminance signal, and a frequency demodulator 310 demodulates the frequency modulated luminance signal and outputs the frequency-modulated luminance signal from a terminal 312 as a luminance signal. The reproduced luminance signal and carrier color signal are mixed in an adder 314 and output as a composite video signal to a terminal 31.
It is possible to output from 6. The reproduced video signal described above is a reproduced video signal of a moving image recorded and reproduced using the conventional color under method.

On the other hand, the still image data superimposed on the vertical scanning blanking period of the reproduced luminance signal is separated from the reproduced luminance signal of the moving image by the gate circuit 320. A clock signal is generated based on the synchronization signal separated from the reproduced luminance signal, and the data detection circuit 32 uses this clock signal as a reference.
2, the data is detected and decoded by the decoder 324. The decoder 324 outputs a luminance signal, an R-Y signal, a B-Y signal, and a mode detection signal.
26, the RY signal reproduction processing circuit 344, the BY signal reproduction processing circuit 346, and the terminal 338. Based on this mode detection signal and the aforementioned clock signal, an expansion circuit 326 for a luminance signal of a still image and a frame memory 3
28 and 330 are controlled so that a field or frame still image is stored in one of the frame memories, and if the next still image is played while reading data from one frame memory, the writing of the other frame memory is controlled. Store in frame memory. When the still image mode is the frame double scanning still image mode, the number of data in one frame is twice the number of data of the video signal in one frame, so both frame memories 328 and 330 are used to store the data.

The still image read from the frame memory passes through a switch 332 and is converted into an analog signal by a digital/analog converter (hereinafter referred to as a D/A converter) 334 to become a luminance signal. Similarly to the luminance signal reproduction processing circuit 343, the RY signal and the BY signal are each converted into analog signals to become the RY signal and the BY signal, which are encoded by the orthogonal converter 348 to 3.58 MHz. The signal is mixed with the luminance signal in an adder 336 and outputted from a still image composite video signal output terminal 340. In addition, the luminance signal, the R-Y signal, and the B-Y signal remain as digital signals at the terminals 342, 350, and 352, respectively.
It is possible to output more.

The printer connected to this recording/reproducing apparatus can print the input field, frame, or frame double-scanning still image signal in response to the mode detection signal output to the terminal 338. A TV monitor can be connected to the still image composite video signal output terminal for monitoring, or a video printer can also be connected. The still image to the printer is preferably output as digital signals of a luminance signal and two color difference signals without passing through a D/A converter from terminals 342, 350 and 352,
By not encoding the color signal and not multiplexing it with the luminance signal, it is possible to prevent the image quality of the print from deteriorating.

As described above, the still image obtained by this embodiment has high image quality because it is recorded and reproduced using digital signals in which the luminance signal is sampled at 13.5 MHz and the color difference signal is sampled at 6.75 MHz. Furthermore, since still image data is recorded and reproduced while being superimposed on the vertical scanning retrace period of the moving image video signal, the mechanical system and tape running system can be configured exactly the same as a conventional VTR; The magnetic tape recorded on the magnetic tape can be used to play moving images on a conventional VTR, and the magnetic tape recorded on a conventional VTR is also compatible in that the reproducing apparatus of this embodiment can play back moving images. Furthermore, since recording and reproducing still image data has no effect on the FM audio signals and PCM audio signals that are simultaneously recorded and reproduced in the deep layer of the magnetic tape, conventional methods that allow these FM audio signals and PCM audio signals to be recorded and reproduced It is also compatible with other VTRs as described above.

In the above embodiment, the luminance signal and two color difference signals of the still image video signal were obtained from the signal processing circuit 12 of the video camera section, but each signal may also be obtained from an external input terminal. . When a composite video signal is input from the outside, the composite video signal is separated into a luminance signal and a carrier signal, and the carrier color signal is demodulated into two color difference signals, an R-Y signal and a B-Y signal, and each A-Y signal and a B-Y signal are demodulated.
/D converter. At this time, the A/D converter 32
The clock signals for the frame memories 34 and 36 are generated based on the synchronization signal of the externally input video signal, and the other clock signals are generated based on the synchronization signal of the moving image video signal recorded at the same time. This results in
A still image of a video signal different from a moving image can be recorded and reproduced without interrupting the recording of a moving image.

Further, in the above embodiment, the video signal for moving images was obtained from the video camera section, but the video signal for the moving image was obtained from the video camera section.
In the case of a TR deck, it can also be a video signal from a television tuner. Since VITS signals and character multiplex signals may be multiplexed during the vertical scanning retrace period of the received video signal, these signals are removed when multiplexing still images. This can be done by replacing the adder 24 with a changeover switch and switching between the moving image signal and the still image digital signal from the encoder 44 using a gate signal.

Furthermore, instead of the luminance signal and two color difference signals, the three primary color signals of R, G, and B can be converted into digital signals, or the composite video signal can be converted directly into digital signals to record still images. It can also be played. Furthermore, although the frame memories used during recording and playback have been described as separate, one frame memory may be shared between recording and playback.

[0032]

As described above, according to the present invention, a still image is generated by converting a video signal of a moving image or a video signal different from the video signal of the moving image into a digital signal, and this still image is converted into a digital signal. Since the video signal of the moving image is recorded and played back in a time-division manner superimposed on multiple horizontal scanning sections within the vertical synchronization retrace section, still images are recorded and played back using digital signals, resulting in high image quality. High image quality can be maintained even when still images are printed using a video printer.

Furthermore, since the still image data is recorded and reproduced while being superimposed on the vertical retrace period of the video signal of the moving image, the mechanical system and tape running system can have exactly the same configuration as a conventional VTR; The magnetic tape recorded on the magnetic tape can be used to play back moving images using a conventional VTR, and the magnetic tape recorded on a conventional VTR can also be used to play back moving images using the playback apparatus of this embodiment. Furthermore, since recording and reproducing still image data has no effect on the FM audio signals and PCM audio signals that are simultaneously recorded and reproduced in the deep layer of the magnetic tape, conventional methods that allow these FM audio signals and PCM audio signals to be recorded and reproduced It is also compatible with other VTRs as described above. Furthermore, it is possible to record and reproduce still images of video signals different from moving images without interrupting the recording of moving images.

Furthermore, according to the present invention, when motion of a still image is detected, one field of one frame is band-compressed to generate a still image, and when no motion is detected, one field of one frame is compressed. A still image is generated by performing double scanning conversion and band compression, and this still image is recorded and reproduced by being time-divisionally superimposed on a plurality of horizontal scanning sections within the vertical synchronization retrace section of the video signal. , when a still image has movement, it records and plays back a large number of still images without blur using a small amount of data, and when there is no movement in a still image, it records and plays back a high-quality still image. It is possible to automatically record and play back high-quality still images with an appropriate amount of data.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram for explaining a recording system according to an embodiment of the present invention.

FIG. 2 is a diagram showing the timing relationship of FIG. 1;

FIG. 3 is a block configuration diagram for explaining double scanning conversion.

FIG. 4 is a block configuration diagram for explaining a reproduction system according to an embodiment of the present invention.

[Explanation of symbols]

10 CCD 12 Signal processing circuit 24 Adder 32 A/D converter 34 Frame memory 36 Frame memory 40 Mode selection circuit 42 Compression circuit 44 Encoder 50 Motion detection circuit 52 Mode signal generator 100 Delay circuit 104 Attenuator 320 Gate circuit 322 Data detection circuit 324 decoder 326 Expansion circuit 328 frame memory 330 frame memory 334 D/A converter

Claims (2)

[Claims] 1. A luminance signal included in a video signal is frequency-modulated into a frequency-modulated luminance signal, a chrominance signal is converted to a frequency band lower than the frequency-modulated luminance signal to produce a low-band-converted chrominance signal, and the frequency-modulated luminance signal is A magnetic recording and reproducing device configured to record and reproduce a multiplexed signal and the low frequency converted color signal, the magnetic recording and reproducing device converting the video signal or a video signal different from the video signal into a digital signal and compressing the band. A magnetic recording and reproducing apparatus that generates a still image and records and reproduces the still image by time-divisionally superimposing the still image in a plurality of horizontal scanning periods within a vertical scanning blanking period of the video signal. 2. A luminance signal included in a video signal is frequency-modulated into a frequency-modulated luminance signal, a color signal is converted to a frequency band lower than the frequency-modulated luminance signal to produce a low-band-converted color signal, and the frequency-modulated luminance signal is A magnetic recording and reproducing device configured to record and reproduce a multiplexed signal and the low frequency conversion color signal, the magnetic recording and reproducing device converting the video signal or another video signal different from the video signal into a digital signal, If movement of the video signal or the other video signal is detected, one field of one frame is band-compressed to generate a still image, and if the movement is not detected, one frame is converted to double scanning. A magnetic recording and reproducing apparatus that performs band compression to generate a still image, and records and reproduces the still image by time-divisionally superimposing it on a plurality of horizontal scanning periods within a vertical scanning retrace period of the video signal.