JPH0793890A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide an information recording and reproducing device which can reproduce a recorded signal while recording in disks having different number of rotations depending on a position of a radial direction, such as CLV recording. CONSTITUTION:This device is provided with an optical head 4 for recording and an optical head 10 for reproducing arranged at the external peripheral side, and recording a signal is externally performed. Rotation of a disk 1 is controlled so that a recording position is made the prescribed linear speed. A reproduced signal is stored in a memory means 17 by a clock signal generated in it, stored data is outputted by the other signal used for recording a signal. Therefore, an information signal read with a linear speed differing from a speed at the time of recording can be returned to the original information signal at the time of recording, also, since read-out can be performed with faster linear speed in recording than a speed at the time of recording, a recorded signal can be continuously reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for recording / reproducing information on / from a plate-shaped recording medium, and stops recording even in a recording / reproducing system in which the number of revolutions of a disk changes at a recording / reproducing position. The present invention relates to an information recording / reproducing device that can be reproduced without performing

[0002]

2. Description of the Related Art For example, there is a demand to watch a program currently being recorded from the beginning, such as when returning home during absence recording. In this case, it is necessary to reproduce without stopping the recording. As an apparatus for realizing such a thing, for example, an optical disk apparatus disclosed in Japanese Patent Laid-Open No. 3-263672 has been proposed. This apparatus is provided with a plurality of independently controllable optical heads for one disk and an input / output request control means for designating which optical head is to perform recording / reproducing, thereby providing a plurality of optical disks. Recording and reproduction can be performed simultaneously by the head.

[0003]

However, in the above-mentioned optical disk device of the prior art, when a plurality of optical heads are simultaneously recording / reproducing on / from one disk, the position of recording / reproducing of which optical head is the same. Even if they are different, the number of rotations of the disk is always constant, which is the CAV recording method.

On the other hand, CL considering long-time recording
There is a recording / reproducing system such as V recording. In this method, the number of rotations of the disc is changed according to the radial position of the disc to be recorded / reproduced for recording / reproduction. In the above-mentioned conventional optical disc device, the CA in which the number of revolutions of the disc is constant.
It is compatible with the V system, and has not been considered to be compatible with the recording / reproducing like the CLV system.

The object of the present invention is to solve the above-mentioned problems of the prior art and to perform recording even in the case of a recording / reproducing system in which the disk rotation speed changes at the recording / reproducing position, such as CLV recording in consideration of long-time recording. An object of the present invention is to provide a recording / reproducing device capable of reproducing without stopping.

[0006]

In order to achieve the above object, according to the present invention, at least a recordable head that can be controlled independently of each other, at least a reproducible head, and a memory means are provided, and a disk is used. The demodulated data is written in the memory means by using the clock signal generated based on the reproduction information signal of 1., and the reading from the memory means is performed by a separately provided predetermined clock signal. Furthermore, a configuration is adopted in which recording is performed on the recording medium from the outer peripheral side.

[0007]

[Function] A recordable head and a reproducible head are provided,
Since each of them can be controlled independently, the recorded signal can be read by the reproducible head even during recording by the recordable head. When the rotational speed of the disc is controlled based on a recordable head, the read information signal to be read will be read at a linear velocity different from that when recording to the disc, and the clock signal included in the read information signal will be read. Is also different from when recording on a disc. The memory means temporarily stores the demodulated data using a clock signal generated based on the reproduction information signal, and the reading is performed based on a predetermined clock signal provided separately. As a result, the read information is restored to the information recorded on the disc.

Further, if the information signal is recorded from the outer peripheral side, and at the same time the already recorded information is reproduced by a separately provided reproducing head, the reproducing head can reproduce the information regardless of the reproducing position. The linear velocity becomes faster than that at the time of recording, and therefore the clock signal included in the reproduction information signal also becomes faster. In this way, the amount of data input to the memory means is larger than the amount of data output from the memory means, so that the reproduction signal output from the memory means is not interrupted. That is, continuous reproduction is possible.

Further, writing to the memory means is performed so that the data input to the memory means is stopped based on the amount of data stored in the memory means or the next input is restarted from the continuation of the input data. Can be controlled to save the memory capacity.

As described above, even in the case of the CLV recording method capable of recording for a long time, the information reproduced at the linear velocity different from that at the time of recording can be restored to the original information and continuously output, so that the data Playback is possible without stopping recording during recording.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

This embodiment will be described by taking a magnetic field modulation type magneto-optical disk device as an example, but the present invention is not limited to this, and may be a phase change type optical disk recording / reproducing device, a laser power intensity modulation type magneto-optical disk device or the like. First, a first embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a block diagram showing the configuration of a first embodiment of an information recording / reproducing apparatus according to the present invention.

Reference numeral 1 denotes a disk which is a magneto-optical recording medium, and is rotated by a motor 2 which is disk rotating means. In the disk 1, for example, in consideration of CLV recording, the guide grooves are slightly wobbled at arbitrary intervals in the track radial direction.

Reference numeral 4 is a recording optical head. Reference numeral 5 denotes a magnetic head, which is mounted at a position facing the objective lens (not shown) of the recording optical head 4 while sandwiching the disk 1. The magnetic head 5 is used when the recording optical head 4 is transferred.
The recording optical head 4 is moved integrally with the recording optical head 4 in the radial direction of the disk. Reference numeral 6 denotes a modulation means, which modulates the recording signal 102 to be recorded on the disc 1 based on a desired modulation method,
The modulated signal 103 is output. A magnetic head driving means 7 drives the magnetic head 5 in accordance with the modulation signal 103 at the time of recording to apply a modulation magnetic field to the disk 1.

Reference numeral 8 is a signal processing means, which is generated from the reflected light signal 101 inputted from a focus error signal for controlling the recording optical head, a tracking error signal 104 and a wobbling signal for controlling the motor. The linear velocity control clock signal 105 is output. Reference numeral 9 denotes a focus / tracking control means, which performs focus, tracking control, and transfer control based on a control signal 104 for controlling the recording optical head 4.

Reference numeral 10 is a reproducing optical head, which is a reflected light signal 10 obtained from the reflected light from the disk 1 during reproduction.
6 is output. Reference numeral 11 is a reproduction signal processing means, which is a focus error signal for controlling the reproduction optical head 10.
A control signal 107 such as a tracking error signal, a linear velocity control clock signal 109 generated from a wobbling signal for controlling the motor 2, and a reproduction signal 110 are output. The reproduction signal 110 is an information signal recorded by the recording optical head 4.

Reference numeral 12 is a focus / tracking control means, which controls the focus, tracking control, and transfer control of the reproducing optical head 10 based on the control signal 107. A selector 13 is a system controller 1
In accordance with the command No. 8, the linear velocity control clock signal 105 obtained from the recording optical head 4 side is selected so that the CLV control is performed with the recording position as a reference during recording and during reproduction during recording, and only reproduction is performed. At the time of rotation, the linear velocity controlling clock signal 109 obtained from the reproducing optical head 10 side is selected so that the CLV control is performed with the reproducing position as a reference, and the linear velocity controlling clock signal 109 is output to the motor control means 14 as the rotation control signal 111. The rotation speed of the disk 1 is controlled by a control signal from the motor control means 14.

Reference numeral 15 is a clock generating means, which generates a clock 113 for reading the memory of the modulating means 6 and the memory means 17 with the system clock 112 as a reference, and a clock extracting means 108 from the system clock 112 and the reproduced signal 110. When the reproduced signal 110 is demodulated by the demodulating means 16 using the generated clock signal, or the demodulated signal 115 demodulated by the demodulating means 16 is used.
To generate a memory write clock 114 used to write the data into the memory means 17.

The memory means 17 includes a write clock 11
4 is used to write the demodulation signal 115 and temporarily store it.
The reproduction signal 116 is output using the read clock 113. Further, the memory means 17 sends a memory remaining amount signal 117 to the system controller 18.

A system controller 18 controls the focus / tracking control means 9 and 12, the motor control means 14 and the selector 13 or various controls such as a recording start position by control signals 118 to 121. By the control signal from the system controller 18, for example, the focus / tracking means 9,
12, a servo control loop is turned on / off, and transfer control of the optical heads 4 and 10 is switched between start and stop; and motor control means 14 performs rotation / stop of the motor 2 and control signal switching processing.

Further, based on the memory remaining amount signal 117 from the memory means 17, the start and stop of writing of data to the memory means 17 and the reading position of the reproducing optical head 10 are correspondingly designated.

Next, the operation of the first embodiment of the information recording / reproducing apparatus according to the present invention shown in FIG. 1 will be described.

First, the recording operation will be described. Focus with the control signal from the system controller 18.
Turn on the servo loop of the tracking control means 9,
The recording optical head 4 is controlled based on the reproduction signal 104, the selector 13 is switched so that the linear velocity control clock signal 105 is selected, and the rotation control of the motor 2 is performed via the motor control means 14.

When recording is started, the recording signal 102 is modulated by the modulating means 6 and then applied to the magnetic head 5 through the magnetic head driving means 7, and the laser beam necessary for recording is applied from the recording optical head 4. The data is recorded on the disk 1 in response to the applied magnetic field while being emitted. This operation is performed until the recording stop command is issued from the system controller 18. At this time, recording of data on the disc 1 is performed from the outer peripheral side to the inner peripheral side of the disc 1.

Next, the operation of reproducing the portion already recorded on the disc 1 from the recording start position while the recording signal 102 is being recorded will be described.

By the control signal of the system controller 18, the servo loop of the focus / tracking control means 12 of the reproducing optical head 10 is turned on, and the reproduction signal 1
The reproduction optical head 10 is controlled based on 07.
The reproduction start position of the reproduction optical head 10 is determined based on the recording start position information stored in the system controller 18, and the reproduction optical head 10 is transfer-controlled to that position. The signal for motor control is supplied to the reproduction optical head 10.
However, since the recording operation is being performed, the selector 13 does not switch and holds the state in which the linear velocity control clock signal 105 is selected as the rotation control signal 111. Therefore, the motor 2 (or the disc 1) is controlled to rotate at the number of rotations corresponding to the position of the recording optical head 4.

Information signal 11 from reproduction signal processing means 11
0 is input to the clock signal extraction means 108, and the clock generation means 15 generates the demodulation clock and the write clock 114 for the memory means 17 based on this signal and the signal from the system clock 112. Based on this clock 114, the reproduction signal 110 from the reproduction signal processing means 11 is demodulated by the demodulation means 16 and then data is written in the memory means 17. The data written in the memory means 17 is read out based on the clock 113 and output as a reproduction signal 116.

Since recording on the disc 1 is performed from the outer peripheral side, the position of the reproducing optical head 10 is closer to the outer peripheral side than the position of the recording optical head. In the case of CLV recording, the number of rotations increases as it goes to the inner circumference side, so the linear velocity in the reproducing optical head 10 becomes faster than that when recording is performed at that position. Therefore, the memory write clock 114 becomes faster than the memory read clock 113, and accordingly, the data transfer rate input to the memory means 17 also becomes faster than the transfer rate output from the memory means 17. Therefore, data is accumulated in the memory means 17 according to the difference in the transfer rates.

Therefore, the memory means 17 outputs a memory remaining amount signal 117 indicating the use condition of the memory to the system controller 18. When the system controller 18 detects that the memory usage amount has increased due to the memory remaining amount signal 117 and the memory write stop amount has been reached, the memory means 1
Writing to 7 is temporarily stopped, and the reproduction position of the disc 1 when writing is stopped is stored. In this state, the memory means 17 is in an output only state, so that the memory usage amount decreases. When the system controller 18 detects from the memory remaining amount signal 117 that the memory usage amount has reached the write restart amount, the writing of data to the memory device 17 is restarted from the position at which the writing to the memory device 17 was stopped. To do so. The system controller 18 then instructs the write operation to be performed as described above until it detects from the memory remaining amount signal 117 that the usage amount of the memory means 17 has increased. After that, the reproduction process is performed by repeating this.

Next, the case where the recording stop command is issued from the system controller 18 during reproduction while recording is described.

The system controller 18 outputs a control signal 118 for turning off the servo control to the focus / tracking control means 9 and also the selector 13
Outputs a control signal 121 to select the linear velocity control clock signal 109 from the reproduction signal processing means 11.
As a result, the motor 2 is controlled via the motor control means 14 according to the linear velocity control clock signal 109 from the reproduction signal processing means 11. That is, the CLV control is performed based on the position of the reproducing optical head 10.

In the case of the reproduction only operation, the recording by the recording optical head 4 is stopped and the reproduction optical head 1 is stopped.
CLV control is performed based on the position of 0.

When recording is started during reproduction, the focus / tracking control means 9 is operated and the number of rotations of the disk 1 is based on the linear velocity control clock signal 105 from the recording optical head 4. Try to do it.

As described above, according to this embodiment, the reproduction information signal 110 read from the disc 1 at a transfer rate different from that at the time of recording is stored in the memory means 17, is temporarily stored, and is the same as at the time of recording. Because it outputs at the transfer rate,
It is possible to continuously reproduce a signal already recorded by using another optical head even while the data is being recorded.

It should be noted that in the present embodiment, even when the reproduction only state is entered, the reproduction signal 116 is transmitted via the memory means 17.
However, as shown in FIG. 2, a selector 20 may be provided between the demodulation means 16 and the memory means 17 so that when only reproduction is performed, it is possible to output without passing through the memory means 17. .

Next, a second embodiment according to the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing a second embodiment of the information recording / reproducing apparatus according to the present embodiment.

In FIG. 3, 1 to 18 and 101 to 12
Since No. 2 is the same as that of the first embodiment, the same reference numeral is given and its explanation is omitted.

Reference numeral 32 is a motor for rotating the disk 1. The motor 32 has a rotation frequency generating means and outputs a rotation speed signal 130 according to the rotation speed. 34
Is a motor control means, and is a linear velocity control clock signal 1 generated from the reflected light signal 101 of the recording optical head 4.
05 or the rotation speed signal 130 to control the rotation speed of the motor 32.

Next, the operation of this embodiment will be described with reference to FIG.

The operation of this embodiment differs from that of the first embodiment in that the motor 32 is controlled when recording is stopped while recording is being performed and when recording is being performed, and when only reproducing is being performed. Is the way.

First, the operation for stopping the recording when the recording and the reproduction are being performed will be described. The motor 32 for rotating the disk 1 is rotated by the motor control means 34 based on the linear velocity control clock signal 105 from the recording optical head 4 at a rotation speed corresponding to the recording position.

When recording is stopped during reproduction, the system controller 18 outputs a control signal 120 to the motor control means 34 so as to maintain the current rotation speed, and
A control signal 11 is sent to the recording optical head 4 to stop recording.
8 is output. The control signal 120 causes the motor control means 34 to control the motor 32 using the rotation speed signal 130 so as to maintain the rotation speed signal 130 from the motor 32 when recording is stopped. By doing so, even if the recording is interrupted during the reproduction while the recording is being performed, the rotation speed at the time when the motor 32 stops the recording can be maintained, and the reproducing optical head 10 is more than the recording optical head 4. Since it is always located on the outer peripheral side, the reproducing optical head 10 can continue reproducing to the position where recording is stopped.

Next, the operation for reproduction only will be described. First, the system controller 18 sends a control signal 120 to the motor control means 34 so as to rotate the disc 1 at a prescribed rotation speed set to be equal to or higher than the rotation speed at the time of recording the innermost circumference, regardless of the reproduction start position. Output. The motor control means 34 determines whether the disc 1
The motor 32 is controlled so that the motor rotates at a specified rotation speed.
At the same time, the system controller 18 instructs the focus / tracking control means 12 to reproduce the optical head 10.
Is transferred to the reproduction start position, and the control signal 119 is output so as to start the reproduction, and the reproduction signal 106 is output as in the first embodiment.
Can be obtained.

When the reproduction is stopped, the system controller 1
8 issues a reproduction stop command to the focus / tracking control means 12 and the motor control means 34. Thereby, the reproduction is stopped and the rotation of the disc 1 is stopped.

It should be noted that in the present embodiment, even when the reproduction only state is reached, the reproduction signal 116 is transmitted via the memory means 17.
However, as shown in FIG. 2, the demodulation means 16
The selector 20 may be provided between the memory means 17 and the memory means 17, and when only the reproduction is performed, the output may be performed without passing through the memory means 17.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing a third embodiment of the information recording / reproducing apparatus according to the present embodiment, and the same elements as those in the first embodiment shown in FIG. 1 described above are designated by the same reference numerals. First, the configuration of this embodiment will be described with reference to FIG. Since 1 to 18 and 101 to 122 are the same as those in the first embodiment, the same reference numerals are given and description thereof will be omitted.

Reference numeral 41 denotes a recording / reproducing optical head, which is shown in FIG.
A signal can be recorded on the disc 1 in the same manner as in, and the signal recorded on the disc 1 can be reproduced in the same manner as the reproducing optical head. The reflected light signal 101 from the disk 1 is inputted to the signal processing means 43, and at the time of recording the signal, it outputs the control signal 104 and the linear velocity control clock signal 105 as in FIG. The signal 135 and the reproduction signal 136 are output.

Unlike in FIG. 1, the motor 2 is always controlled in its rotation speed by the linear velocity control clock signal 105 obtained from the recording / reproducing optical head 41.

The information signal 136 obtained from the recording / reproducing optical head 41 and the information signal 110 obtained from the reproducing optical head 10 are input to the information signal selector 47, and as will be described later, the control signal 140 of the system controller 18 is input.
Either of them is selected and output to the clock signal extraction means 108.

Similarly, reproduced signal 136 and reproduced signal 110
Is input to the demodulation signal selector 44 and selects either one in accordance with the control signal 139 of the system controller 18 and outputs the reproduction signal 138 to the demodulation means 16.

Next, the operation of the third embodiment will be described with reference to FIG.

The operation when only recording a signal on the disk 1 is exactly the same as in FIG.

When only reproducing is performed next, the output of the laser emitted from the recording / reproducing optical head 41 is lowered to a level almost similar to that of the reproducing optical head 10, and the information signal selector 47 selects the information signal 136. Output.
Other operations are the same as those in FIG.

When reproducing the recorded signal while recording the signal on the disc 1, the information signal selector 47 selects the information signal 110 obtained from the reproducing optical head 10, and the demodulation signal selector 44 similarly reproduces the reproduced signal. Select 110. Other operations are the same as those in FIG.

Next, the operation when the recording is stopped while the signal is being recorded and reproduced is as follows.

The system controller 18 switches the operation of a laser power control circuit (not shown) to stop the recording of the recording / reproducing optical head 41, and then outputs the laser beam in substantially the same manner as the reproducing optical head 10. Then, the control signal 118 is output to the focus / tracking control means 9 so as to move the recording / reproducing optical head 41 to the reproducing position of the reproducing optical head 10.
The system controller 18 controls the control signal 14 so as to switch the information signal selector 47 and the demodulation signal selector 44 when the reproduction positions of both the optical heads 41 and 10 are aligned.
0 and 139 are output.

By the above operation, the reproduction signal 116 can be continuously obtained even when the recording is stopped.

When recording is started during reproduction of the signal by the recording / reproducing optical head 41, the system controller 18 causes the focus / tracking control means 12 to reproduce the reproducing optical head 10 from the recording / reproducing optical head 41.
The control signal 119 is output so as to move to the reproduction position. The system controller 18 uses the reproduction optical head 1
When it is detected that 0 is located at the same position as the recording / reproducing optical head 41, the control signal 14 so that the information signal selector 47 and the demodulation selector 44 select the reproduction signal 110.
0 and 139 are output. After that, recording / reproducing optical head 4
1 is moved to a predetermined position to record a signal.

In this embodiment also, as shown in FIG. 5, the selector 2 is input before being input to the memory means 17.
0 may be provided, and the reproduction signal 106 may be output by the selector 20 without passing through the memory means 17 when only reproduction is performed.

A transfer mechanism for the two optical heads in each of the above-described embodiments will be described.

FIG. 6 shows a first embodiment of the optical head transfer mechanism.

Reference numeral 4 denotes a recording optical head, which is guided and supported by guide shafts 61 and 62 so as to be movable in the radial direction of the disk 1, and a coil 63 is fixed to the lower surface thereof. The coil 63 is arranged in the magnetic gap of the magnetic circuit 64, and by energizing the coil 63, the recording optical head 4 can be moved in the radial direction of the disk 1. 1
Reference numeral 0 is a reproducing optical head, and the guide shafts 66, 6
The coil 68 is guided and supported by 7, and a coil 68 is fixed to the lower surface thereof. The coil 68 is arranged in the magnetic air gap of the magnetic circuit 69.

FIG. 7 shows a second embodiment of the optical head transfer mechanism. Reference numeral 4 denotes a recording optical head, which is guided and supported by guide shafts 71 and 72, and has a coil 7 on its lower surface.
3 is fixed. 10 is an optical head for reproduction,
Similarly, it is guided and supported by the guide shafts 71 and 72,
The coil 76 is fixed to the lower surface thereof. Coil 73
And 76 are placed in the magnetic air gap of the common magnetic circuit 74,
By energizing the coils 73 and 76 respectively, the recording optical head 4 and the reproducing optical head 10 can be independently moved in the radial direction of the disk 1. In this embodiment, the guide shaft and the magnetic circuit are common to the two optical heads, as compared with the first embodiment shown in FIG.
The configuration can be simplified.

FIG. 8 shows a third embodiment of the optical head transfer mechanism. A recording optical head 4 is guided and supported by guide shafts 81 and 82, and a coil 83 is fixed to the lower surface thereof. Reference numeral 10 is a reproducing optical head, which is guided and supported by guide shafts 82 and 86, and a coil 87 is fixed to the lower surface thereof. The coils 83 and 87 are arranged in the magnetic air gap of the common magnetic circuit 84. Also in this embodiment, the guide shaft and the magnetic circuit are common to the two optical heads as compared with the first embodiment shown in FIG. 6, and the configuration can be simplified.

[0065]

In the information recording / reproducing apparatus according to the present invention, an optical head for recording a signal on the disc and an optical head for reproducing the recorded signal are used, and the signal is recorded from the outer periphery to the inner periphery of the disc. And towards
The reproducing optical head reproduces information on the outer peripheral side of the disk as compared with the recording optical head. The rotation of the disk is controlled so as to have a specified linear velocity at the recording position of the recording optical head. As a result, the linear velocity of the disc at the reproducing position of the reproducing optical head is always higher than the prescribed linear velocity.

On the other hand, the reproduction signal is demodulated by the clock signal generated from the reproduction signal itself and stored in the memory means, and the data of the stored reproduction signal is output by another clock signal used for signal recording.

With the above configuration, like CLV recording,
It is possible to reproduce a signal recorded at a linear velocity according to the reproduction position of the disc.

[Brief description of drawings]

FIG. 1 is a block diagram of a magneto-optical recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a magneto-optical recording / reproducing apparatus showing another example of the first embodiment according to the present invention.

FIG. 3 is a block diagram of a magneto-optical recording / reproducing apparatus showing a second embodiment according to the present invention.

FIG. 4 is a block diagram of a magneto-optical recording / reproducing apparatus showing a third embodiment according to the present invention.

FIG. 5 is a block diagram of a magneto-optical recording / reproducing apparatus showing another example of the third embodiment according to the present invention.

FIG. 6 is an explanatory view showing a first embodiment of the optical head moving mechanism of the information recording / reproducing apparatus according to the present invention.

FIG. 7 is an explanatory view showing a second embodiment of the optical head moving mechanism of the information recording / reproducing apparatus according to the present invention.

FIG. 8 is an explanatory view showing a third embodiment of the optical head moving mechanism of the information recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk, 2, 32 ... Motor, 4, 41 ... Recording optical head, 6 ... Modulation means, 8 ... Signal processing means, 10 ... Reproduction optical head, 11 ... Reproduction signal processing means, 14, 34 ... Motor control Means, 15 ... Clock generating means, 16 ... Demodulating means, 17 ... Memory means, 18 ... System controller, 20 ... Selector, 108 ... Clock signal extracting means, 104 ... Recording optical head control signal, 107 ... Reproducing optical head control Signals, 105, 109 ... Linear velocity control clock signals, 110 ... Reproduction signals, 111 ... Rotation control signals, 113 ... Read clocks, 114 ... Memory write clocks, 116 ... Reproduction signals, 117 ... Remaining memory signals, 130 ... Rotation Number signal.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Toru Sasaki Toru Sasaki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Video Media Research Laboratory, Hitachi, Ltd. (72) Inventor Junichi Ishii 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Visual Media Research Laboratory (72) Inventor Kuniichi Onishi Stock, Hitachi Ltd. Visual Media Research Laboratories, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa

Claims (7)

[Claims] 1. An information recording / reproducing apparatus for recording / reproducing a plate-shaped recording medium recorded / reproduced by the CLV system,
A recordable head and a reproducible head are provided and controlled independently of each other, and when recording is performed on a plate-shaped recording medium, the linear velocity is controlled based on the recording position,
When only the reproduction is performed, the linear velocity is controlled based on the reproduction position, and the memory means for temporarily storing the signal read from the plate-shaped recording medium is provided so that the recording and the reproduction can be simultaneously performed. Characteristic information recording / reproducing apparatus. 2. The information recording / reproducing apparatus according to claim 1, wherein recording / reproducing is performed from the outer peripheral side of the plate-shaped recording medium. 3. The recording / reproducing apparatus according to claim 1, wherein a clock signal generated from the reproduction information signal is used when the reproduction information signal from the plate-shaped recording medium is written in the memory means. An information recording / reproducing apparatus characterized in that a predetermined clock signal is used for reading. 4. An information recording / reproducing apparatus according to claim 1, 2 or 3, wherein when the reproduction only is performed, the information is directly output without passing through the memory means. 5. The information recording / reproducing apparatus according to claim 1, wherein the input to the memory means is stopped or started and the reproduction start position of the reproducing head is controlled based on the remaining memory capacity of the memory means. An information recording / reproducing apparatus characterized by the above. 6. An information recording / reproducing apparatus having a recordable head and a reproducible head, wherein both heads are moved in the same direction. 7. The information recording / reproducing apparatus according to claim 6, wherein the distance between the signal reading portions of both heads is equal to or less than the diameter of the innermost circumference of the disk recording area.