JPH0746531A - Recording device and reproducing device - Google Patents

Abstract

PURPOSE:To provide the recording and reproducing device which can stably possess image information at the plural kinds of special reproducing speed and can reproduce satisfactory reproduced picture quality by intermittently arranging the data of pictures on a tape pattern. CONSTITUTION:Among the image data which band is compressed by a band compressing circuit 3, the most basic data are transferred to an A data buffer 5 by a data distributor 4 and among the image data which band is compressed, the remaining image data are transferred to a B data buffer 6 by the data distributor 4 and stored. When heads 11 and 12 come to prescribed positions on a tape 13, a switch 7 is changed over, the basic component is separately recorded at one part of tracks on the intermittently selected tape 13 through an ID adding circuit 8, transmission encoder 9 and recording amplifier 10 and at the time of high-speed reproducing, this component is possessed so as to output the reproduced image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type recording / reproducing apparatus for recording / reproducing a large amount of data such as a digitized video signal, which can be reproduced at a reproducing speed different from normal reproducing. The present invention relates to a recording / reproducing device such as a VTR.

[0002]

2. Description of the Related Art Conventionally, as a special reproduction method in a digital recording VTR, for example, a method disclosed in Japanese Patent Laid-Open No. 2-94071 has been known. In this method, still image information extracted from a video signal is arranged on a tracing pattern on a plurality of tracks during high-speed reproduction.
According to this method, the tracing pattern corresponds to one kind of special reproduction speed other than the standard reproduction.

[0003]

However, in the VTR having such a conventional structure, only one kind of speed can stably acquire still image information as special reproduction, but one kind of special reproduction speed in the VTR. Is not enough. Therefore, in order to support a plurality of trick play speeds with this method, it is necessary to arrange data on a plurality of tracing patterns in a duplicated manner, and there is a problem that the data becomes wasteful and the data is wasted. .

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide a recording / reproducing apparatus which reproduces an image having good reproduction image quality at a plurality of special reproduction speeds.

[0005]

According to the present invention, a basic component of a video signal is extracted from a unit of a video signal composed of several frames, divided into a plurality of segments, and one of the tracks selected intermittently. It is equipped with a means for recording in the section, and outputs the reproduced image by acquiring this component during high speed reproduction.

Further, during faster high speed reproduction, one frame is acquired from each of a plurality of recording units and output.

[0007]

By arranging the data as described above, the data for reproducing the image can be effectively acquired even at a plurality of reproduction speeds.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a recording / reproducing apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a recording / reproducing apparatus in an embodiment of the present invention.

In FIG. 1, an input signal from the input terminal 1 is A
The video signal digitized by the D converter 2 is compressed by the band compression circuit 3. The band compression circuit 3 is generally configured based on, for example, a discrete cosine transform (DCT), but it does not relate to the essence of the present invention, and the higher order bits of an image such as digitized data are used as basic data. It is not necessary to use a plurality of upper bits including at least the most significant bit of the video signal. In addition, compression using a variable length code such as Huffman code may be used together.

The most basic data of the image data band-compressed by the band compression circuit 3 is transferred to the A data buffer 5 by the data distributor 4. The remaining image data of the band-compressed image data is transferred to the B data buffer 6 by the data distributor 4. The data buffers 5 and 6 are composed of memories, temporarily store each data, and the reading is stopped until the head comes to a predetermined position on the tape.

When the head reaches a predetermined position on the tape, the switch 7 is switched to output the data from the data buffer. The output data is added with a data ID representing the position and component of the image by the ID adding circuit 8, and is further subjected to an error correction code by the transmission encoder 9 and then modulated. The modulation method may be general digital modulation such as NRZI or 8-14 modulation. The data modulated by the transmission encoder 9 is recorded on the tape 13 from the recording amplifier 10 via the heads 11 and 12.

At the time of high speed reproduction, the tape 13 is the capstan 1
4 and a pinch roller 15 are used to drive the tape in a direction indicated by an arrow at a speed higher than that at the time of recording, and a reproduction signal reproduced from the heads 11 and 12 is transmitted and decoded through a preamplifier 16 and a reproduction equalizer 17. The demodulator 18 demodulates and corrects the error.

The reproduced data is subjected to a decoding process, which is the reverse of the compression at the time of recording, at the decoder 19, and is stored at the position on the frame buffer 21 at the address checked by the ID detector 20. The frame buffer 21 is sequentially read at a constant rate, DA-converted by the DA converter 22, and output as a video signal.

FIG. 2 shows the recorded pattern. In FIG. 2, the video signals sequentially input are
To 24. The video signal is divided into M tracks in units of N frames and recorded, but one frame of the basic component 25 is taken out from the N frames and divided into L segments. A tape 2 which is selected so that the basic components divided horizontally are arranged at equal intervals in a recording area unit for N frames composed of a unit of M tracks.
The data is transferred from the A data buffer 5 of FIG. 1 to the L locations 27 to 31 (L = 5 in the drawing) on the recording medium 6 and recorded.

Since the L recording locations 27 to 31 in the recording unit come to the same position in the next recording unit, L must be selected as a factor of the number M of tracks (M ÷ L is an integer).

At least the data other than the basic component is transferred from the B data buffer 6 and recorded in the remaining portion 32 on the tape. In this case, the data transferred to the B data buffer 6 may be compressed using the correlation between frames.

As the basic component, one frame among N frames may be selected. However, since there is a lot of data as it is, it is efficient to perform band compression before recording. For example, as shown in FIG. 3, among the conversion coefficients obtained by the discrete cosine conversion of 8 × 8 pixels of the video signal, the DC component 33 and the low frequency component 34 may be divided into L parts from the top of the screen and arranged.

As a result, it is possible to obtain a reproduced image composed of a DC component and a low frequency component at the M / L speed. Also, for every frame of N frames, one frame is N
It is decomposed into divided segments, and N pieces of each segment (1 / N frame) are collected from each frame to form basic data 25 for one frame. It can also be recorded.

In this case, there is no limitation on the method of division into N division and L division. When N division is a division that can have a horizontal boundary on the screen, L division can be a division that can have a vertical boundary on the screen. .

Further, when N = L is selected, segmentation of L division and L division can be made common, so that there is an advantage that the circuit scale can be reduced if the same division method is adopted.

In this case, since only one segment is extracted as a basic component from one frame, at least the data obtained independently, such as compression using correlation between frames, is used for decoding within this segment. Processing that cannot be done cannot be used. However, the other segments of this frame do not have such a limitation, and compression using correlation between frames may be used.

A broken line 35 shown in FIG. 2 indicates the scanning locus of the head during high speed reproduction. As shown in FIG. 2, the head does not scan all M tracks at the time of high speed reproduction.
÷ When the tape is run at a speed of L times, the basic components 27 to 31 divided into L segments can be obtained. In this case, phase control is required to properly send the capstan and allow the head to pass where the basic component is. This is a household VTR currently on the market
In the above, the technique is usually used for fixing the noise bar at a fixed position on the screen during special reproduction for easy viewing.

When M = 40 and L = 5, M ÷ L is 8, and
The broken line 35 indicates 8 × speed, and the basic components of the video can be reproduced by running at 8 × speed. When a specific one frame is selected from the unit of N frames and recorded as a basic component, a good reproduction image quality can be obtained at 8 times speed. Reverse M
÷ The same applies to the L speed.

Since the basic components 27 to 31 are arranged substantially in the center of the track and the direction of the head scanning and the center line of the track form an angle, the length is limited to the length obtained when the head crosses the track. Is recorded. In the figure, the center of the truck is shown, but basically any part of the truck can be used.

Next, the case where the tape is fed at a higher speed will be described with reference to FIG. FIG. 4 shows the tracks on the tape of FIG. 2 for a longer period. In FIG. 4, a recording unit 37 consisting of M N frames is recorded on the tape 36.
To 41 are recorded continuously. Further, in each recording unit, a basic component divided into L segments is recorded at L locations.

The tape is fed at (M + M ÷ L) times the recording speed, and the head locus is as shown by 70. For example, M
= 40 and L = 5, the speed is 48 times. The tape is (M +
When sent at a speed of (M ÷ L), data is acquired so that the segment of the head locus sequentially advances from 42 to 46 in adjacent recording units as shown in the figure, and one frame divided into L locations by L times of scanning. Minute video data can be acquired.

FIG. 5 shows a reproduction frame at a speed of (M + M ÷ L). The L segments are sequentially acquired from the L recording units 37 to 41 by L head scans, and 1
It is possible to obtain the reproduced image output of the frame. Each segment is temporally separated by one recording unit (N frames), and the frame number forming each segment is as shown in FIG. 5, where J is the frame number of the first segment.

Further, although the screen is divided horizontally into five, it may be divided vertically. Basically, when the color difference signal is included in the component method in addition to the luminance signal,
Basic information may be extracted from the luminance signal and the color difference signal to form an image. In addition to the video, basic information such as a time code representing the page of the video frame may be arranged. This makes it possible to detect the time code automatically at the time of high-speed reproduction and detect the time.

Basically, the number M of tracks constituting one frame has been described as 40, but this is an example, and 32 or 12 tracks are the same. Moreover, although it was explained with L = 5,
Any value may be used as long as it is a factor of M.

A group is formed for each of a plurality of frames, and intraframe compression is performed only for one of the intraframes, and interframe compression is used for the other frames in the group.
In the case of using the MPEG compression method described in the August 1992 issue, page 124, intraframe data may be used as a basic component.

As described above, in the structure of this embodiment, when a high-speed reproduction image is reproduced at a plurality of special reproduction speeds, the basic component of the data of the entire screen can be obtained. Image quality can be obtained. Further, if the basic data is used also in the standard speed reproduction, it is not necessary to add additional data for special reproduction, so that efficient recording can be performed.

Although the head structure has been described with two heads in the embodiment of FIG. 1, the same applies to the pair head shown in FIG. 6 having two types of azimuths. In FIG. 6, + azimuth heads 48 and 49 and −azimuth heads 50 and 5 are arranged on the drum 47.
1 is attached. The pair heads having different azimuth angles are attached with different heights corresponding to the track width so that two parallel tracks are formed on the tape during recording.

In this case, one track in FIG. 2 becomes the pair track 52 as shown in FIG. 7, and the basic components of the image are arranged at the L positions of the L pair track.

The case where the two or two pairs of heads mounted facing each other are of the same type has been described above.

Next, a case will be described in which the azimuth angles of the heads mounted facing each other are different from each other as + and −. FIG. 8 shows heads 53 and 54 mounted opposite to each other.
Are set to different azimuth angles. As a result, the tape pattern recorded on the tape is as shown in FIG. During recording, + azimuth heads and −azimuth heads alternately form tracks, so that + azimuth tracks 56 and −azimuth tracks 57 are alternately formed on the tape 55.

By the way, since the +/- azimuth and -azimuth heads alternately scan the head locus of the M / L speed, the azimuth angle of the track including the basic component divided and placed at L points is + and-. Must be recorded alternately. For this purpose, it is necessary that the interval M / L of the basic components divided and placed at L points is an odd number, for example, M = 4.
When 2, L = 6 and M / L becomes an odd number. In the figure, +
The head scanning locus at the time of M / L double speed of azimuth is 58,-
The head trace of azimuth is shown at 59. The + azimuth angle of the track is + -alternate, and the head scan is also + -alternate,
It is possible to obtain 60 to 61 basic components.

Further, the higher speed M + M / L double speed is shown in FIG.
Shown in. As in the case of FIG. 4, the data arranged at the L position in the recording unit composed of M tracks can be acquired by the operation of L times. FIG. 10 shows the L unit of recording units 62 to 63 by M tracks shown in FIG. 9, and the scanning locus 64 of the M + M / L double speed + azimuth head.
And-azimuth head locus 65 is shown. Similar to FIG. 9, the track and head have the same azimuth, and data can be efficiently acquired.

Although the structure of the recording / reproducing apparatus is shown in this embodiment, it goes without saying that the structure may be composed of only the recording apparatus or the reproducing apparatus.

[0039]

As described above, according to the present invention, by arranging the basic components of the video signal intermittently on the tape pattern, it is possible to obtain good reproduction image quality at a plurality of special reproduction speeds. In home VTRs and commercial VTRs, the high-speed playback function is very important for cueing and quick viewing, but if the image quality is poor at this time, it will be difficult to cue out and check the contents. By improving the image quality of VTR, it is possible to provide a VTR having a very high utility value.

[Brief description of drawings]

FIG. 1 is a block diagram showing a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a tape pattern diagram of a recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of image compression data according to an embodiment of the present invention.

FIG. 4 is another tape pattern diagram of the recording / reproducing apparatus of the present embodiment.

FIG. 5 is a diagram showing a playback frame at (M + M ÷ L) double speed.

FIG. 6 is a configuration diagram of a rotating drum according to another embodiment of the present invention.

FIG. 7 is another tape pattern diagram of the recording / reproducing apparatus of the present embodiment.

FIG. 8 is a diagram showing head arrangements with different azimuths mounted facing each other.

9 is a detailed view of a portion of the tape pattern of FIG.

FIG. 10 is another tape pattern diagram of the recording / reproducing apparatus of the present embodiment.

[Explanation of symbols]

 1 Input Terminal 2 AD Converter 3 Band Compression Circuit 4 Data Distributor 5 A Data Buffer 6 B Data Buffer 7 Switch 8 ID Addition Circuit 9 Transmission Encoder 10 Recording Amplifier 11, 12 Heads 13 Tape 16 Head Amp 17 Reproduction Equalizer 18 transmission decoder 19 decoder 20 ID detector 21 frame buffer 22 DA converter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location 7734-5C H04N 5/93 Z (72) Inventor Masaaki Kobayashi 1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric Sangyo Co., Ltd.

Claims (11)

[Claims] 1. A helical scan system in which a tape is spirally wound around a rotary drum, and a video signal is divided and recorded in units of N frames (N: natural number) over M (M: a plurality) tracks on the tape. A recording device, wherein 1 is selected from the units of the video signal composed of the N frames.
And a recording unit that modulates both the separated basic component and the remaining component and records the different components on the tape at different locations. The L components (L is a factor of M) are divided into first to L segments, and the M tracks are on recording tracks selected so as to be equidistant from each other on a tape surface. A recording apparatus, which sequentially records at a portion of L locations and records at least video signal components other than the basic components at locations on the tape other than the portion of the L locations. 2. The recording apparatus according to claim 1, wherein one frame selected from N frame video signal recording units is separated as a basic component of the video signal and divided into L parts for recording. 3. A screen of one frame is divided into N segments, and one frame made by sequentially collecting segments constituting one screen from each of the N frames is separated as a basic component of a video signal. 2. The recording apparatus according to claim 1, wherein the recording is performed by dividing into L and L. 4. The recording apparatus according to claim 1, wherein the basic component of the video signal is a low frequency component of the components obtained by discrete cosine transforming the video signal. 5. The recording apparatus according to claim 1, wherein a plurality of upper bits including at least the most significant bit of the digitized video signal are used as a basic component of the video signal. . 6. A basic component dividing method for dividing and arranging L divided L tracks into intermittently selected L tracks, and an image of one frame is divided into L segments in order from a plurality of adjacent scan lines. 6. The recording apparatus according to claim 1, wherein the recording apparatus is divided and sequentially arranged on L tracks for recording. 7. As a basic component dividing method for dividing and arranging L dividedly into L tracks which are intermittently selected, an image of one frame is divided into L segments in order from a plurality of adjacent pixels. The recording apparatus according to any one of claims 1 to 6, wherein the recording apparatus sequentially arranges and records on L tracks. 8. A tape traveling speed faster than that at the time of recording, comprising a tape traveling means for traveling the tape at a speed faster than that at the time of recording and a reproducing means for demodulating a reproduced signal to reproduce a video signal. Characterized in that the head acquires the first to Lth segments arranged at L positions on the tape surface where the video signal corresponding to N frames is recorded over M tracks, and the video signal is reproduced. Playback device. 9. Traveling at a speed N times that at the time of reproduction and recording,
A video signal is reproduced by sequentially acquiring, by a head, the first to Lth segments arranged at L locations on a tape surface on which a video signal corresponding to N frames is recorded over M tracks. Item 10. The reproducing device according to item 8. 10. A video signal is obtained by running at a speed faster than N times that at the time of recording at the time of reproduction, by the head from the tape surface recorded on more than M tracks of the first to Lth segments. The reproducing apparatus according to claim 8, which reproduces. 11. When reproducing and running at a speed of (M + M ÷ L) times that at the time of recording, the first to Lth segments are sequentially arranged from adjacent L units of recording units consisting of N frames. The reproducing apparatus according to any one of claims 8 to 10, wherein the reproducing apparatus acquires and reproduces a video signal.