JPH02177038A - Video recorder - Google Patents

Abstract

PURPOSE:To record and reproduce plural pieces of information in parallel by alternately recording and reproducing plural pieces of video and sound information simultaneously supplied on a magneto-optical disk at intervals of fine time in parallel. CONSTITUTION:Faint magnetic field H is previously impressed on the magneto-optical recording layer 56 of the magneto-optical disk 11 by a magnetic field generation source 57. When the desired area of the layer 56 with submicron order is irradiated with a laser beam 59a through an objective lens 58, the temperature of the irradiated part 56a rises and the magnetization is reversed. Thereafter, the direction of the magnetization of the part 56a is kept as it is even when the temperature lowers. In the case of erasing, it is good that the desired area is irradiated with the light beam 59a in a state where the magnetic field in an opposite direction to the magnetic field H is impressed. Reproducing is performed by a laser light beam 59b for reproducing whose plane of polarization is linearly polarized light. By radiating the magnetization to an upward part 56a, the linearly polarized light rotates clockwise and by radiating it to a downward part 56b, it rotates counterclockwise. The difference of the rotating direction is taken as the intensity of light by an analyzer 61 and is detected by a photodetector 62, thereby detecting the information on the layer 56. Thus, the plural pieces of information are alternately recorded and reproduced in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is equipped with a magneto-optical disk as a recording medium and is capable of recording a plurality of video/audio signals supplied simultaneously, for example, video/audio signals of a plurality of channels in television broadcasting. This invention relates to a video recorder that can record audio information in parallel.

[Conventional technology]

A videotape 1 conventionally used for recording television video and audio signals has a film-like tape base 2 made of polyester, as shown in FIG.
A magnetic member 3 made of gamma iron oxide or gamma iron oxide to which cobalt is added is coated thereon.

On this video tape 1, a signal current corresponding to the recording signal is passed through a coil 5 wound around a magnetic head 4, so that a magnetization pattern 6 corresponding to the recording signal is formed, and a signal is recorded. There is.

[Problem to be solved by the invention]

However, the videotape 1 as described above has a problem in that the amount of information that can be recorded is limited. Furthermore, since information is recorded and played back while the video tape 1 is running, it takes several seconds to several tens of seconds to write desired information to a predetermined position or read information from a predetermined position. It took quite a long time. Therefore, for example, it has been impossible to record information on multiple channels that are simultaneously provided in television broadcasts in parallel.

Therefore, conventionally, in the video tape 1, only one type of video/audio signal is recorded continuously and sequentially on the tracks arranged on the magnetic material member 3, and the playback is also performed along the tracks. was.

[Means to solve the problem]

In order to solve the above problems, a video recorder according to the present invention includes a magneto-optical disk as a recording medium, and
A recording device configured to alternately record a plurality of simultaneously supplied video/audio information on the magneto-optical disk at minute time intervals in parallel, and to extract and reproduce any recorded video/audio information.・It is characterized by being equipped with a reproduction means.

[For production]

According to the above configuration, since a magneto-optical disk is adopted as the recording medium, sufficient storage capacity can be obtained, and the recording/reproducing means can be accessed at a desired recording position on the magneto-optical disk at high speed. It becomes like this. Therefore, for example, multiple video and audio information supplied simultaneously, such as video and audio information of multiple channels in television broadcasting, etc.
It becomes possible to record audio information alternately and in parallel, and to extract and reproduce any recorded video/audio information. As a result, it is possible to provide a video recorder with low utilization value.

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

As shown in FIG. 2, the video recorder includes a spindle I2 on which a magneto-optical disk 11 as a recording medium is placed and rotated at high speed.

Along with the playback system 27, which will be described later, the video recorder's recording and
The recording system 13 constituting the reproduction means includes a laser drive device 14 that converts video and audio information supplied from a television (not shown) into optical signals and drives a laser diode 15.
It is equipped with

Laser light emitted from the laser diode 15 in response to video/audio information from the television is transmitted through the lens 16.
, prism I7, polarizing beam splitter 18, mirror 2
The light is guided to the magneto-optical disk 11 via a 0.1/4 wavelength plate 21 and an objective lens 22. And a magnetic field generation power source 2
Video and audio information is recorded on the magneto-optical disk 11 by applying a magnetic field generated by a magnetic field generation source 24 connected to the magneto-optical disk 11 together with the laser beam.

Further, the light reflected from the magneto-optical disk 11 is guided to the polarizing beam splitter 18 via the objective lens 22, the quarter wavelength plate 21, and the mirror 20.
8 and is reflected at right angles. Thereafter, the reflected light is received by a light receiving element 26 via a prism 25, and a focus error in the recording system 13 is detected by the light receiving element 26.

On the other hand, the reproduction system 27 uses a laser diode 28 as a light source.
The laser light emitted from the laser diode 28 is guided to a diffraction grating 32 via a lens 30 and a prism 31, and is split into three beams by the diffraction grating 32. After that, the laser light that has become three beams passes through the polarizer 33 and the lens 3.
4. Mirror 35, half mirror 36 and objective lens 37
is guided to the magneto-optical disk 11 via the.

The light reflected from the magneto-optical disk 11 is reflected almost at right angles by the half mirror 36, and reaches the 70-30% mirror 40 via the lens 38.1. Here, the light is separated into transmitted light and reflected light. The reflected light of this light is received by the light receiving element 42 via the cylindrical lens 41, and a focus error in the reproduction system 27 is detected based on this light.

Further, the light that has passed through the mirror 40 by 70 to 30% reaches the half mirror 43, where it is separated into transmitted light and reflected light again. The transmitted light and reflected light are analyzed by analyzers 44 and 45, respectively.
The 0th-order lights are received by photodiodes 46 and 47, and the 1st-order lights are received by photodetectors 48a and 48b.
, 49a and 49b.

The outputs of the photodiodes 46 and 47 are then compared by a comparator 51 to obtain a main signal. On the other hand, the outputs of the light receiving elements 48a and 48b and the outputs of the light receiving elements 49a and 49b are compared by the comparators 52 and 53, respectively, and the outputs of the comparators 52 and 53 are further compared by the comparator 54. , a tracking error signal is obtained.

Next, the principle of recording on and reproducing from the magneto-optical disk 11 will be explained based on FIG.

As shown in FIG. 3(a), the magneto-optical disk 11 includes a transparent substrate 55 and a magneto-optic recording Fi56.

When recording information on the magneto-optic recording layer 56, a weak magnetic field H is applied in advance to the magneto-optic recording layer 56 by a magnetic field generation source 57 in a direction in which the magnetization is reversed. Although this magnetic field H alone does not cause reversal of the magnetization of the magneto-optic recording layer 56,
With the magnetic field H applied, as shown in Figure 3(b),
When a desired area of submicron size in the magneto-optic recording layer 56 is irradiated with the recording laser beam 59a through the objective lens 58, the temperature of the area 56a irradiated with the laser beam 59a rises. A reversal of the magnetization of portion 56a occurs.

Thereafter, even if the temperature of the region 56a where the magnetization has been reversed decreases, the same magnetization direction is maintained as shown in FIG. 3(C). Note that when erasing, it is sufficient to irradiate the laser beam 59a while applying a magnetic field in the opposite direction to the magnetic field H described above.

As shown in FIG. 3(d), when reproducing information recorded on the magneto-optical record N56, the reproduction laser beam 59b emitted from the laser light source 60 is transmitted through the optical system shown in FIG. 2, for example. The magneto-optic recording layer 56 is irradiated with the light beam. At this time, the polarization plane of the reproducing laser beam 59b is normally linearly polarized light that vibrates in only one direction.

This linearly polarized light rotates clockwise when the magnetized portion 56a of the magneto-optical recording 7156 is irradiated upward, and on the other hand, when the other portion 56b is irradiated with downward magnetization, it rotates to the left. rotate around. Therefore, the information on the magneto-optical recording layer 56 can be detected by converting the above-mentioned difference in the rotation direction into the intensity of light using the analyzer 61 and detecting the intensity of the light using the light receiving element 62.

Next, a method of recording video/audio information onto the magneto-optical disk 11 will be explained.

In this first embodiment, video/audio information of a plurality of channels supplied simultaneously in television broadcasting is recorded alternately and in parallel at minute time intervals on different tracks of the magneto-optical recording layer 56 for each channel. I try to do that.

As shown in FIG. 1, a track address recording area 63 is provided in a part of the circumferential area of the transparent substrate of the magneto-optical disk 11. As shown in FIG. In the track address recording area 63, track addresses indicating the number from the outermost circumference of each track 64 formed concentrically at a pitch on the order of several μm in the magneto-optic recording layer 56 are recorded as submicron-order pits. It is recorded in advance as a row of (unevenness). This track address is read by laser light.

Now, the images of three channels C4 to C3 that are simultaneously supplied in television broadcasting are stored on the magneto-optical disk 11.
Consider the case where audio information is recorded in parallel.

Expressing the video/audio information of each channel C8 to c3 as a function of time, fe, (t), fcz(t),
Let f C5(t). If each piece of information is divided into n minute time intervals Δt, f c i (t) = f
c i (Δt)+fci(2Δt)+・・・・・・+
fci(nΔL) (where i=1 to 3).

In this case, as shown in Table 1, fc, (Δt) is first recorded on the track with track address "1" on the outermost circumference of the magneto-optical disk 11, and then fc, (Δt) is recorded on the track with track address "2" on the outermost circumference of the magneto-optical disk 11.
Then, fci (3ΔL) is recorded in the track with track number “3”. Thereafter, in the same manner, information on each channel 01 to C1 is recorded alternately and in parallel at intervals of minute time Δ.

Table 1 In that case, the relationship between the information of each channel c, to C3 and the track on the magneto-optical disk 11 in which it is recorded is as follows:
It will look like this:

(3 to 2)th track: fct((3k 2)
Δt) (3 to -1)th track: fcz((3k
l) ΔL) 3rd track: rC3 (Δt to 3)
(However, ≧1: Integer) In other words, the information on channel C5 is 1.4.7,...
... fc on the (3 to 2)th track.

(Δt), fct(4Δt), fcl(7Δ1),
-... fCt ((3k 2) Δt) will be recorded.

Also, the information on channel C2 is 2.5.8,...
・ fc on the (3-1)th track, (Δt) fc
z(5Δt), fcz(8Δt), = f C
z((3 to -1)Δt) will be recorded.

The same applies to the information on channel C8.

Next, the three channels c recorded on the magneto-optical disk 11
Among the information 1 to c3, for example, when reproducing information on channel C2, fc, (Δt), fct( 4
Δt), fct(7Δ1), -・----fct(
(3k 2) Δt), and similar processing is performed when reproducing information on channels C2 and C3.

Here, fct(j)=Σfc+(kΔt,) >fct(Δt)+fC+(4Δt)+f c +
(7Δt)+・・・・・・+f c, ((3k-2)
.DELTA.L), and if the information of the three channels C3 to c3 is recorded in parallel, the amount of information will be reduced compared to the case where only the information of channel CI is recorded, but if .DELTA.L is made sufficiently small, no problem will occur.

[Example 2] Next, a second embodiment will be explained.

As shown in FIG. 4, in the second embodiment, for example, each track 64 of the magneto-optical disk 11 is divided into a plurality of sectors 64a to 4, for example, by dividing a group provided on a transparent substrate into a plurality of arc regions. It is divided into 64d. Each sector 64 is provided between adjacent sectors on the transparent substrate.
Sector address storage areas 65, 65, corresponding to a to 64d
... is provided. Sector address storage area 65/65
. . . record the sector address indicating the sector number of each sector 64a to 64d and the track address of the track 64 to which each sector 64a to 64d belongs.

For example, channel 3 C of television broadcasting.

When recording the video/audio information of ~c3 in parallel, sectors 64a~64c of each track 64 are used. As shown in Table 2, first, fc, which is the information of channel C1, is stored in the sector 64a at sector address +1111 at sector address "1" in the track 64 at track address "1°" on the outermost circumference.

(Δt) is recorded.

Next, fcz(2Δt), which is information on channel C2, is recorded in sector 64b at sector address ``°2'', and then fct(3Δt), which is information on channel C3, is recorded in sector 64c at sector address ``3pa''. Hereinafter, the information of channels CI"-C3 is similarly recorded sequentially in each sector 64a to 64c at sector addresses "1" to "3" in the track 64 after track address "2". .

That is, sectors 64a to 64 at sector addresses "'1" to "3" in the k-th track 64 (k≧1=integer)
The relationship between c and the information recorded there is as follows.

Sector address "1'": f c, ((3k-2)Δt
) Sector address ° “2”: fcz ((3k l)Δt)
Sector address “3”: fcs (Δt to 3) On the other hand, when reproducing information on channel c, for example,
Sector 64 at sector address “1” in each track 64
It is sufficient to extract and read the information of only a. Channel C
2. The same applies to the reproduction of C3.

In each of the above embodiments, recording and reproduction of video/audio information on the magneto-optical disk 11 is performed using the magneto-optical disk 11.
This configuration uses a laser beam to record data along tracks 64 with a pitch of several micrometers while rotating the tape at high speed, so information can be recorded at a higher density and at higher speeds than with the conventional magnetic recording method using video tape. It becomes possible to write and read information.

Next, a modification will be explained.

In each of the above embodiments, the video/audio information of multiple channels provided simultaneously in television broadcasting is extracted and recorded at predetermined time intervals. You can also record everything. In that case, it is necessary to provide a storage means to temporarily store the information of other channels while the information of one channel is being recorded on the magneto-optical disk. When reproducing information, a sharper image can be obtained.

Further, in the above embodiment, a case has been described in which video and audio information of multiple channels of television broadcasting are recorded in parallel, but according to the present invention, in addition to that, video and audio information of television broadcasting can be recorded. It is also possible to record video/audio information that has already been recorded on another recording medium such as an 8 mm video tape recorder onto the magneto-optical disk of the present video recorder in parallel.

〔Effect of the invention〕

As described above, the video recorder according to the present invention includes a magneto-optical disk as a recording medium, and records a plurality of simultaneously supplied video and audio information on the magneto-optical disk alternately and in parallel at minute time intervals. In addition, the configuration includes a recording/reproducing means configured to extract and reproduce any recorded video/audio information.

As a result, a magneto-optical disk was adopted as the recording medium, and sufficient storage capacity was obtained.
This allows the reproducing means to access a desired recording position on the magneto-optical disk at high speed. Therefore, for example, multiple pieces of video/audio information supplied at the same time, such as video/audio information of multiple channels in television broadcasting, are recorded alternately and in parallel, and any recorded video/audio information is extracted. It becomes possible to play it. As described above, according to the present invention, it is possible to provide a video recorder with high utility value in the -layer.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is a schematic plan view showing a magneto-optical disk, FIG. 2 is an explanatory diagram showing the overall configuration of a video recorder, and FIG. Figure (a
) to (d) are explanatory diagrams showing the principle of recording and reproducing on a magneto-optical disk, FIG. 4 is a schematic plan view showing a magneto-optical disk in another embodiment of the present invention, and FIG. 5 is a diagram showing a conventional video tape. FIG. 3 is a schematic front view showing a recording method. 11 is a magneto-optical disk, 13 is a recording system (recording/reproducing means), and 27 is a reproducing system (recording/reproducing means). flute drawing

Claims (1)

[Claims] 1. A magneto-optical disk is provided as a recording medium, and a plurality of simultaneously supplied video and audio information is recorded on the magneto-optical disk alternately and in parallel at minute time intervals,
A video recorder comprising a recording/reproducing means configured to extract and reproduce any recorded video/audio information.