JPH02272893A - Method of recording and reproducing high-vision still picture - Google Patents

Abstract

PURPOSE:To record and reproduce one sheet of picture in one sec. or below by band-compressing and time-division-multiplexing a luminance signal and a chrominance signal to be digitized, converting them to analog signals, FM- modulating them, and recording them to an optical disk. CONSTITUTION:The method is equipped with a recording system processing part 2, an FM modulator 3, an FM demodulator 4 and a reproducing system processing part 9, the luminance signal and chrominance signal are A/D- converted, respectively, and they are stored to a frame memory. They are time-base-expanded, thereafter, time-division-multiplexed, converted to the analog signals by a D/A converter, thereafter, FM-modulated and recorded onto the optical disk by using a single optical head. At the time of reproducing, a regenerative signal from an optical head 4 is FM-demodulated, thereafter, it is A/D- converted, the luminance signal and chrominance signal are stored to the frame memory, respectively, they are time-base-compressed, and read. Thus, by utilizing the optical head 4 and a driving mechanism 5 of a magneto-optical disk device, the recording and reproducing can be executed in 0.5sec. per one frame.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a still image recording and reproducing method for recording and reproducing high-definition still images on an optical disk device, and particularly to a signal processing method thereof.

[Conventional technology]

Video recording and reproducing devices using optical discs have already been put into practical use, but currently they are compatible with the NTSC television system, and analog recording systems with FM modulation are the mainstream, and the video band is 4.2 MHz. ~5 MHz, and the rotational speed of the optical disk is 1800 rpm, which is appropriate for the current technological level.

Hi-Vision, which is a so-called HDTV system that has been recently developed and displays high-definition images, has 1125 horizontal scanning lines, more than double the conventional one, and has a video bandwidth of 20M1 for luminance signals. (z, 6MI in color signal (
z and a very wide band. Therefore, it is possible to obtain high-quality images that are close to those of printed matter or photographs, and as a recording/playback device for this,
In addition to VTRs, the development of disk recording and reproducing devices is being considered.

However, as mentioned above, it is necessary to process extremely wideband video, so for video, for example, the video signal is
It is necessary to adopt complicated methods such as dividing into channels and expanding the time axis for each channel, reducing the occupied band of the recorded video signal, and recording and reproducing in parallel with two beams of laser light. 1 with a 30cm diameter disc
The performance time is only about 0 minutes, and the price is still far from practical use.

On the other hand, a disk device that uses high-quality high-definition video to record and play back still images consisting of high-definition signals for the purpose of video libraries such as art, substitutes for printed materials such as product catalogs, applications in the education and medical fields, etc. is being developed. This device is somewhat more practical for moving pictures, and with the recent practical use of magneto-optical disks,
It is now possible to realize an optical disc device like TR that can easily record and reproduce information.

Conventionally, two methods have been considered for recording the above-mentioned high-definition signals.

One is a digital method, in which digitized high-definition signals are stored in a memory, and this information is transferred at a technically possible speed and recorded on an optical disc.

The other method is an analog method, but in this case, there are the same problems as in the case of video recording, and if you try to record the video signal in one channel, the system band is 30 to 40 MHz, which is extremely high. As a result, there is a need for a wider band, which requires higher disk rotation speeds and larger diameter disks, which necessitates higher output laser light sources, unstable servo systems, and larger systems. It becomes complicated and expensive.

Therefore, at present, attempts are being made in various fields to develop devices mainly using digital methods.

[Problem to be solved by the invention]

However, when recording high-definition signals using digital methods, it takes 2 to 4 images to record one image.
It requires an amount of information of MB, and at the current transfer rate of optical discs, it takes 5 to 10 seconds to record and reproduce each. Furthermore, when using a 5.25-inch magneto-optical disk, only about 200 images can be stored.

Furthermore, in order to improve the transfer rate, attempts are being made to artificially increase the transfer rate and bandwidth by using multiple optical heads or using multiple drive devices, as in the case of video recording. However, the problem is that the system becomes complicated and expensive, and a practical device for recording and reproducing still images using the high-definition system has not yet been obtained.

In consideration of the above-mentioned problems, the present invention has been devised to make it possible to record and reproduce one image in less than one second without using multiple heads or using multiple drive devices. The purpose of this invention is to provide a high-definition still image recording and reproducing method.

[Means to solve the problem]

In order to solve the above-mentioned problems, the high-definition still image recording and reproducing method according to the present invention is a high-definition still image recording and reproducing method for recording and reproducing a high-definition television signal. After storing it in the frame memory and expanding the time axis,
These time-axis expanded luminance signals and chrominance signals are time-division multiplexed, converted into analog signals by a D/A converter, and then FM modulated, and this FM modulated signal is transmitted using a single optical head. It is recorded on an optical disk, and during playback, the playback signal from the optical head is FM demodulated and then A/D converted, and the luminance signal and color signal are each stored in a frame memory and read out after compressing the time axis. It is characterized by

[Function] As mentioned above, during recording, the digitized luminance signal and color signal are stored in the frame memory at high speed, and then band-compressed to 1/12 and 1/4, respectively. Since the data is divided and multiplexed into one channel and then recorded on the optical disc, the recording time per frame is shortened to about 0.5 seconds. Furthermore, recording is possible with a single optical head similar to that used in magneto-optical disks that are already in practical use, and the rotational speed of the optical disk may be the same (1800 rpm).

Also, one frame can be recorded on 15 tracks, so 5.
Using a 25-inch magneto-optical disk, more than 1000 frames can be recorded.

During playback, the playback output from the optical disc is digitized, then converted into two channels of luminance and color signals, stored in the frame memory, and read out at high speed, so it takes about 0.5 seconds just like during recording. You can play it quickly.

Therefore, by using the optical head and disk drive mechanism of current magneto-optical disks, one high-definition still image can be
A still image recording and reproducing method that can record and reproduce in seconds or less becomes possible.

〔Example〕

An embodiment of the present invention will be described below based on FIGS. 1 to 3.

In the high-definition still image recording and reproducing apparatus shown in FIG. 1, a video signal input from an input terminal 1 is digitized by a recording system processing section 2, and then is converted back into an analog signal after time axis expansion and band compression. However, this analog signal is FM-modulated by the FM modulator 3 to drive the semiconductor laser light source of the optical head 4, and is applied to the part of the optical disk 6 rotated by the spindle motor 5 at a speed of 180 rpm to which the magnetic field is applied by the magnet 7. , are sequentially recorded by a modulated semiconductor laser light source. During reproduction, the FM signal wave output from the optical head 4 is demodulated by the FM demodulator 8, and the demodulated video signal is subjected to time axis compression in the reproduction system processing section 9.

As a result, the video signal processed by the recording system processing section 2 is restored and outputted from the output terminal 10.

Details of the recording system processing section 2 in FIG. 1 are shown in FIG.
Details of the reproduction system processing section 9 are shown in FIG.

As shown in FIG. 2, the recording system processing section 2 has an input terminal 11 to which a luminance signal (hereinafter referred to as a Y signal) and a color signal (hereinafter referred to as a C signal) Pr and Pb of a high-definition video signal are input.・Out of 12 and 13, input terminal 1
1 is connected to the input side of the Y signal A/D converter 14, and input terminal 12 and input terminal 13 are connected to the C signal A/D converter 14, respectively.
It is connected to the input side of converters 15 and 16.

The output side of the Y signal A/D converter 14 is connected to the input side of the Y frame memory 17, and the C signal A/D converters 15 and 1
The output sides of the vertical filters 6 are connected to the input sides of the vertical filters 18, and the output sides of the vertical filters 18 are connected to the input sides of the C frame memory 19.

The output sides of the Y frame memory 17 and C frame memory 19 are both TCI (Time Comprehensive).
sSed Integration) encoder 20
The output side of this TCI encoder 20 is connected to the input side of a D/A converter 21, and is also connected to a memory controller 27, which will be described later. D/A
The output side of the converter 21 is an LPF (Low Pa5s
The output side of the LPF 22 is connected to the output terminal 23.

Furthermore, the recording system processing section 2 is equipped with a clock generator 24 that generates 48.6M7 clock signals.
The output side of this clock generator 24 is connected to a 1/3 frequency divider 25.
and the input sides of the 1/12 frequency divider 26, and are also connected to the memory controller 27 that controls the Y frame memory 17 and the C frame memory 19. The output of this memory controller 27 is input to the control terminals of the Y frame memory 17 and C frame memory 19.

In addition, the 1/3 frequency divider 25 and the 1/12 frequency divider 26
The output side of is connected to the input side of the memory controller 27 as well as the output side of the clock generator 24, and the output side of the 1/12 frequency divider 26 is connected to the synchronization signal, burst signal and flag signal. Synchronous signal ROM28 that generates
and the TCI encoder 20, and the output side of the synchronization signal ROM 28 is also input to the TCI encoder 20.
It is input to the encoder 20.

Next, in the reproduction system processing section 9 of FIG. 3, an input terminal 29 to which information from the optical disk outputted from the optical head 4 is manually input is connected to the input side of the A/D converter 30.
The output side of the A/D converter 30 is connected to the input side of the time base corrector 31.

The output side of the time axis corrector 31 is connected to the input side of the TCI decoder 32, and the output side of the TCI decoder 32 is connected to both the Y frame memory 33 that stores the Y signal and the C frame memory 34 that stores the C signal. has been entered.

The output side of the Y frame memory 33 is connected to the input side of a synchronization adder 35 that adds a synchronization signal.
The output side of 5 is connected to the input side of the D/A converter 36,
The output side of the D/A converter 36 is connected to the input side of the LPF 37, and the output side of the LPF 37 is connected to the Y signal output terminal 38.

On the other hand, the output side of the C frame memory 34 that stores the C signal is connected to the input side of an interpolation filter 39, and the C signals Pr and Pb returned to two channels by the interpolation filter 39 are sent to the D/A converter. The output sides of the D/A converters 40 and 41 are connected to the input sides of LPFs 42 and 43, respectively, and the output sides of LPFs 42 and 43 are connected to the input sides of C signals Pr and Pb, respectively. It is connected to output terminals 44 and 45.

Furthermore, this reproduction system processing section 9 is equipped with a clock generator 46 that generates 48.6M7 clock signals.
The output of this clock generator 46 is input to a 173 frequency divider 47 and a 1/12 frequency divider 48, and is also input to the Y
It is connected in parallel to a memory controller 49 that controls the frame memory 33 and the C frame memory 34, an interpolation filter 39, and control terminals of each of the D/A converters 36, 40, and 41.

Further, the output side of the 1/12 frequency divider 48 is connected to the A/12 frequency divider 48.
It is connected in parallel to each control terminal of the D converter 30, the time axis corrector 31, and the TCI decoder 32. In addition,
The output side of the memory controller 49 is connected to each control terminal of the Y frame memory 33 and the C frame memory 34.

In the above configuration, in the recording system processing section 2, the Y signal and C signal (Pr and pb) of the high-definition video signal are inputted from the input terminals 11 to 13, respectively, and are digitized by the A/D converters 14 to 16. Ru. In this case, the sample rate of the Y signal is 48.6M7, and the sample rate of the C signal is 16.2MHz, each of which is digitized with 8 bits, and the Y signal is directly stored in the Y frame memory 17.
The Pr and Pb signals are stored in the vertical filter 18
After being converted into one channel via the C frame memory 19, the signal is stored in the C frame memory 19.

This stored video signal is read out via the memory controller 27 at 4.05 MHz from the 1/12 frequency divider 26, but at this time, the synchronizing signal ROM 2B, the C frame memory 19 and the Y frame memory 17 are sequentially read out according to the reference signal via the memory controller 27 according to the command of the TCI encoder, and the TCI encoder reads out the 2
The video signal of one channel and the synchronization signal of one channel are converted into one channel (TCI processing).

As described above, the one-channel signal is returned to an analog signal by the D/A converter 21 and output to the output terminal 23 via the LPF 22 (TCI signal).

The time-axis expanded TCI signal of one channel is FM-modulated by the FM modulator 3 in FIG. Ru. At this time, the optical disk 6 is rotating at a speed of 1800 rpm, and the power of the semiconductor laser light source can be 10 mW or less, so that current magneto-optical disk devices can be used.

Now, the ratio of the bands of Y signal and C signal is n:l (n is an integer)
Then, 1 [k (n+1) −a = 1125
−・・ ■m=に−n
... The following relationship must be satisfied. m
and k correspond to the band compression multiple of the Y signal and C signal, respectively.

Here, l: Number of horizontal scanning lines per track (integer) Also, m>By/Bm... ■B
y: Original Y signal bandwidth Bm: Recording bandwidth of optical disc (baseband band during FM modulation) The value is

[k (n+1) 1] tb>aT −...
■Here, T: 1 horizontal period time tb2 Of the above T, invalid part time not related to video B)' = 20.0MHz, Bm = 2.0MHz, ■ From formula m>10, m=12, and n=
From 20 (MHz) / 6 (MHz), n=3
Then, from equation 0, k=4. Therefore, in equation 0, if tb=0.127T, a<1.90
5, a=1. Therefore, from ■, we obtain j2=1125/[4(3+1)-11=75. That is, 75 horizontal scanning lines can be recorded on one track of the magneto-optical disk 1. Alternatively, the number of tracks required to record one frame is 15. Therefore, the time required to record one frame is 0.5 seconds.

Next, during reproduction, the reproduction signal output from the optical head is input to the input terminal 29 of the reproduction system processing section 9 shown in FIG. 3, and is digitized by the A/D converter 30. Since this digitized signal includes a time axis error, the time axis corrector 31 removes the time axis error, and inputs it to the TC decoder 32, which separates the Y signal and C signal, and converts them into Write to the Y frame memory 33 and C frame memory 34 with a write clock of 4.05 MHz. The Y signal written in the Y frame memory 33 is read out by a 48°6 MHz read clock via a memory controller 49. The read Y signal is added with a synchronization signal by a synchronization adder 35, converted to an analog signal by a D/A converter 36, and outputted to a Y signal output terminal 38 via an LPF 37.

On the other hand, the C signal written in the C frame memory 34 is
In the recording system processing unit 2, since the vertical filter 18 converts the channel into one channel, the memory controller 49 converts the channel into one channel.
After being read out by a 6.2 MITz read clock, it is returned to the original two channels by an interpolation filter 39, converted to analog by D/A converters 40 and 41, and then converted to an analog signal by an LPF 42.
- Through 43, output terminal 44 for Pr signal and Pb signal
and output to 45. At this time, the time required for reproduction is 0.5 seconds, the same as for recording.

As described above, according to the high-definition still image recording and reproducing method of the present invention, the time required for recording and reproducing can be performed in 0.5 seconds each, and since one frame can be accommodated in 15 tracks, 5 If a .25-inch magneto-optical disk is used for recording at a track pitch of 1.6 μm, about 1,200 still images can be recorded, which is sufficient for practical use.

〔Effect of the invention〕

As described above, the high-definition still image recording and reproducing method according to the present invention records and reproduces high-definition television signals in order to obtain high-definition televised still images using an optical disc. In this method, each luminance signal and chrominance signal are A/D converted, stored in a frame memory, and time-axis expanded, and then these time-axis expanded luminance signals and chrominance signals are time-division multiplexed and D/A converted. This FM modulated signal is recorded on an optical disk using a single optical head, and during playback, the reproduced signal from the optical head is FM demodulated and then FM modulated. /D conversion, and the color signal and color signal are respectively stored in a frame memory, compressed on the time axis, and read out.

This makes it possible, for example, to use the optical heads and drive mechanisms of magneto-optical disk devices that are already in practical use.
It is now possible to record on a magneto-optical disk at 0.5 seconds per frame and reproduce it in 0.5 seconds, and by using a 5.25-inch magneto-optical disk,
A practical recording and reproducing device that can record more than 00 still images and provides high-definition still images for art and other video libraries, substitutes for printed materials such as product catalogs, and materials in the educational and medical fields. This has the effect of being able to be realized at low cost.

It is a diagram.

FIG. 2 is a block diagram showing the detailed configuration of the recording system processing section of the high-definition still image recording and reproducing apparatus.

FIG. 3 is a block diagram showing the detailed configuration of the reproduction system processing section of the high-definition still image recording and reproduction apparatus.

2 is a recording system processing section, 4 is an optical head, 9 is a reproduction system processing section, 17 and 18 are frame memories, 20 is a TCI encoder, 24 is a clock generator, 32 is a TCI decoder, 3
3 and 34, the frame memory 46 is a clock generator.

[Brief explanation of drawings]

1 to 3 illustrate one embodiment of the present invention.

Claims (1)

[Claims] 1. In a high-definition still image recording and reproducing method for recording and reproducing high-definition television signals, each of a luminance signal and a color signal is A/D converted and stored in a frame memory, and the time axis is expanded. Afterwards, these time-axis expanded luminance signals and color signals are time-division multiplexed and D
/A converter converts the signal into an analog signal and then performs FM modulation. This FM modulated signal is recorded on an optical disk using a single optical head. During playback, the reproduced signal from the optical head is FM demodulated. A high-definition still image recording and reproducing method characterized in that the luminance signal and the color signal are subsequently A/D converted, stored in a frame memory, compressed on the time axis, and read out.