JP2001155431A - Device and method for reproducing multi-track disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for reproducing a multi-track disk without the need for a large buffer memory. SOLUTION: In the method for reproducing the multi-track disk, the signals of the plural tracks of a prescribed interval recorded in an information disk 1 such as a CD are parallelly reproduced, the outputted respective read signals of the plural tracks are converted into digital data and outputted, the parallelly outputted data are stored in a memory for data alignment and aligned in the order of addresses on the information disk 1 and aligned valid data are outputted. The interval of the tracks to be parallelly reproduced is changed corresponding to the remaining capacity of the memory 9 for the data alignment and the storage capacity per rotation of the information disk of the track during reproduction at present.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for an information disk and a reading method therefor, and more particularly, to a disk reproducing apparatus for reading data of a plurality of tracks from an optical disk used for a CD-ROM or the like in parallel, and a reproducing method therefor. About.

[0002]

2. Description of the Related Art In recent years, a high-speed reading function has been required for an optical disk device such as a CD-ROM device. As a method for realizing the function, a multi-track disk reproducing device for reading data of a plurality of adjacent tracks in parallel has been proposed by various companies. Proposed. Among them, JP-A-10-154
No. 336 discloses a method of performing multiple track scanning of an optical pickup by simultaneously irradiating a plurality of beams on a plurality of tracks of a disk, wherein Nj is the number of jump tracks, Nb is the number of light beams (the number of simultaneously reproduced tracks), Ng is an interval between light beams (an interval between tracks to be described later), and Nr is a number of reproduction tracks during a reproduction cycle, where Nj = (Nb−1) · Ng−1 and Nr = Nb ·
Ng-1 is satisfied, and with this configuration, the interval between light beams and the number of track jumps are fixed at optimized values, thereby realizing high speed operation without increasing the rotation speed of the spindle motor. A multi-track scanning method is provided.

The operation of reading a track in this multi-track scanning method will be described with reference to FIG. FIG. 5 is a simplified enlarged view of a track of a CD-ROM disk. Numeral 1 is an information disk composed of a CD-ROM disk, whose tracks are formed in a spiral shape,
.., T3,.
T3, T4, ... are connected to the next track.

Considering a case where three tracks are simultaneously read (Nb = 3) and the track interval is set to 2 (Ng = 2), the data of each track is read from the beginning of T1, T3 and T5. After reading the data for two rotations, the three playback tracks become T
3, reaches the beginning of T5 and T7. Here, in order to reproduce the data of the next unread track, Nj = 3 track jumps are performed, and each reproduced track is set to Tj.
6. Track jumps must be made to T8 and T10.

At this time, the data alignment buffer memory has to arrange the data in the order of the tracks and output the data to the outside of the apparatus in the order of the tracks. The capacity is required to be multiplied by the number of tracks (Nr), and practically, when the playback track is advanced, considering that the data of the previous track still remains in the buffer memory, the buffer capacity is about twice this. Capacity is required.

[0006]

In the case of a disk such as a CD-ROM recorded at a constant linear velocity, the storage capacity per one rotation of the disk changes between the inner and outer peripheral portions of the disk. A buffer memory must be prepared in accordance with the maximum storage capacity per rotation at the outer periphery of the disk having the largest storage capacity per rotation, and the frequency of track jumps increases as the spacing between the reproduction beams increases. On the other hand, although the capacity is reduced, the required capacity of the buffer memory for data alignment increases, but when reading data near the inner circumference, the buffer memory is not effectively used, and a larger buffer memory is required according to the track interval.

An object of the present invention is to provide a multi-track disc reproducing apparatus and a multi-track disc reproducing method which do not require a large buffer memory.

[0008]

According to the present invention, a plurality of tracks are formed spirally or concentrically on a recording surface, and the data recording capacity of a track per rotation is determined by the radial position. In a multi-track disc reproducing apparatus which reproduces signals of a plurality of tracks on this information disk in parallel and which is recorded so as to change, a reproduction track interval variable means for changing an interval between tracks to be reproduced in parallel, A signal reproducing unit that reproduces signals of a plurality of tracks in parallel; a data converting unit that converts each of the output read signals of the plurality of tracks into digital data and outputs the digital data; and stores the data output in parallel. A data alignment memory for aligning addresses in order on the information disk, and Data output means for outputting the data to the outside of the disc reproducing apparatus, and the interval between tracks to be reproduced in parallel according to the remaining capacity of the data alignment memory and the storage capacity of the currently reproduced track per rotation of the information disk. And the number of effective tracks to be reproduced in parallel.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a multi-track disc reproducing apparatus according to the first aspect of the present invention, a plurality of tracks are formed spirally or concentrically on a recording surface, and one track is defined by a radial position.
Tracks that are recorded on an information disk such that the data recording capacity of the tracks per rotation changes, and tracks that are reproduced in parallel in a multi-track disk reproduction device that reproduces signals of a plurality of tracks in parallel on the information disk at fixed intervals Means for varying the track spacing, signal reproducing means for reproducing signals from a plurality of tracks in parallel from an information disk, and converting each of the read signals from the plurality of tracks into digital data for output. A data conversion means for storing data output in parallel, a data alignment memory for storing the data output in parallel and arranging them in the order of addresses on the information disk, and a data output for outputting aligned valid data to the outside of the disk reproducing apparatus Means for storing the remaining capacity of the data alignment memory and the track currently being reproduced. Be adapted to the storage capacity per rotation distribution disk 1, it is characterized in changing the distance of the track to be reproduced in parallel.

According to a fifth aspect of the present invention, there is provided a multi-track disk reproducing method, wherein a plurality of tracks are formed spirally or concentrically on a recording surface, and the data recording capacity of the tracks per one rotation depends on the radial position. It is recorded on the information disc so as to change, the signals of a plurality of tracks at predetermined intervals on the information disc are reproduced in parallel, and the read signals of the plurality of output tracks are converted into digital data and output. A multi-track disk reproducing method for storing data output in parallel in a data alignment memory, aligning the data in an address order on an information disk, and outputting aligned effective data, wherein the remaining capacity of the data alignment memory is reduced. Tracks to be reproduced in parallel are adapted to the storage capacity per revolution of the information disc of the currently reproduced track. It is characterized in changing the interval.

With these configurations and methods, the interval between tracks to be reproduced in parallel is changed in accordance with the remaining capacity of the data alignment memory and the storage capacity of the currently reproduced track per rotation of the information disk. Buffer memory capacity for data alignment can be set to the minimum necessary,
Even in a portion where the recording capacity per disk rotation is small, the prepared data alignment buffer memory can be used to the maximum extent.

In the multi-track disc reproducing apparatus according to the second aspect of the present invention, a plurality of tracks are formed spirally or concentrically on the recording surface, and the data recording capacity of the track per rotation changes depending on the radial position. As described above, in a multi-track disk reproducing apparatus which reproduces signals of a plurality of tracks in parallel at a constant interval on the information disk, the intervals of tracks to be reproduced in parallel are arranged at a constant interval. A signal reproducing means for reproducing signals of a plurality of tracks in parallel from an information disk, a data converting means for converting each of the read signals of the plurality of tracks into digital data and outputting the digital data, A data alignment memory for storing data and aligning the data in the order of addresses on the information disk; Data output means for outputting effective data to the outside of the disc reproducing apparatus; and the remaining capacity of the data alignment memory, the storage capacity per track of the information disc for the currently reproduced track, and the interval between tracks to be reproduced in parallel. And control means for changing the effective number of tracks to be reproduced in parallel in accordance with the number of tracks.

According to a sixth aspect of the present invention, there is provided a multi-track disk reproducing method, wherein a plurality of tracks are formed spirally or concentrically on a recording surface, and the data recording capacity of a track per rotation is determined by a radial position. It is recorded on the information disc so as to change, the signals of a plurality of tracks at predetermined intervals on the information disc are reproduced in parallel, and the read signals of the plurality of output tracks are converted into digital data and output. A multi-track disk reproducing method for storing data output in parallel in a data alignment memory, aligning the data in an address order on an information disk, and outputting aligned effective data, wherein the remaining capacity of the data alignment memory is reduced. Effective playback for parallel playback by adapting to the storage capacity per revolution of the information disk of the currently playing track It is characterized in changing the number of racks.

With these configurations and methods, the number of effective tracks to be reproduced in parallel is changed in accordance with the remaining capacity of the data alignment memory and the storage capacity of the currently reproduced track per information disk rotation. This eliminates the need for a reproduction track interval variable unit that changes the interval between tracks to be reproduced in parallel, makes it possible to reduce the buffer memory capacity for data alignment to the minimum necessary, and even in a portion where the recording capacity per disk rotation is small, In addition to maximizing the use of the buffer memory for data alignment, if the remaining capacity of the buffer memory for data alignment is low, the system does not perform the operation of storing useless playback track data. Can be the minimum.

According to a third aspect of the present invention, there is provided a multi-track disk reproducing apparatus as set forth in the first aspect, wherein the remaining capacity of a data alignment memory and the information disk 1 of a track currently being reproduced. The feature is to change the interval between tracks to be played back in parallel and the number of effective tracks to be played back in parallel according to the storage capacity per rotation, and to minimize the buffer memory capacity for data alignment. Even if the recording capacity per rotation of the disk is small, the prepared data alignment buffer memory can be used to the fullest extent, and if the remaining capacity of the data alignment buffer memory is reduced, useless playback is performed. Since the operation of storing track data is not performed, the power consumption of the system can be minimized. .

According to a fourth aspect of the present invention, there is provided a multi-track disk reproducing apparatus, wherein the information disk is a CD.
-A disc conforming to the ROM standard, in which tracks are formed in a spiral and recorded at a constant linear velocity, and the capacity of a buffer memory for data alignment can be minimized. Even in a portion where the recording capacity per rotation is small, the prepared data alignment buffer memory can be used to the maximum. (Embodiment 1) Hereinafter, claims 1 and 4 of the present invention will be described.
A first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram of a multi-track disk reproducing apparatus according to the first embodiment of the present invention. Reference numeral 1 denotes an information disk, for example, an optical disk, a magnetic disk, a magneto-optical disk, or the like, in which tracks are recorded in a spiral shape, and the recording capacity per disk rotation varies depending on the radial position of the information disk 1, for example, a line. It is recorded in a format such as a constant velocity (CLV), a constant linear velocity (ZCLV) for each section, and a constant angular velocity (ZCAV) for each section. Reference numeral 2 denotes a disk drive, which rotates the information disk 1 at a predetermined speed. Reference numeral 3 denotes a read head as a signal reproducing means, for example, an optical disk device, an optical pickup in a magneto-optical disk device, a magnetic head in a magnetic disk device, etc., which are movably installed in the radial direction of the information disk 1 and are provided in plurality. Data on a plurality of tracks is reproduced in parallel on the information disc 1 at predetermined intervals. Reference numeral 4 denotes a read head driving device,
Is driven in the radial direction to move to the target track. Reference numeral 6 denotes a servo circuit which performs servo control in the focus and tracking directions of the optical pickup when the read head 3 is an optical pickup. 5 is a head amplifier,
The signal reproduced in parallel from the read head 3 is amplified and converted into a signal of an appropriate magnitude. Reference numeral 7 denotes a digital signal processing circuit as data conversion means, which converts a signal output in parallel from the head amplifier 5 to digital data, and demodulates and decodes the data if modulation or encoding is performed, and outputs the data in parallel. I do. Reference numeral 9 denotes a data alignment memory, and reference numeral 10 denotes a memory controller. The memory controller 10 sequentially aligns data output in parallel from the digital signal processing circuit 7 on the data alignment memory 9 from the beginning of the data. Numeral 11 denotes data reading means as data output means for reading data reproduced in parallel and outputting the data to the outside of the disk reproducing apparatus. 8 is a control means, for example, C
A controller such as a PU controls the disk drive 2, the read head drive 4, the servo circuit 6, the digital signal processing circuit 7, the memory controller 10, and the data reading means 11.

Further, the control means 8 changes the interval between tracks to be reproduced in parallel according to the remaining capacity of the data alignment memory 9 and the storage capacity of the currently reproduced track per rotation of the information disk. There is provided a reproduction track interval changing means 8a. Further, the read head 3 is provided with a mechanism for physically changing the interval between a plurality of reproduction tracks.

The data reproducing operation is performed as follows. FIG. 2 is an information disc 1 illustrated for explaining the first embodiment of the present invention, in which tracks are formed in a spiral shape. When the interval between the tracks to be reproduced is 1, the tracks to be reproduced simultaneously are T1, T2, T
3. . . It becomes like. Reproduction is performed with the rotation of the information disk 1, and tracks T1, T2, T3. . . Are tracks T2, T3, T4. . . When the beginning of the track is reached, a track jump is performed to advance the playback track. At this time, the information disc 1 continues to rotate during the track jump, and the tracks T4, T
5, T6. . . Of the track T3, T4, T5... Only one track jump is performed. . . Resume playback from the middle of. When the interval between the tracks to be reproduced is 2, the tracks to be reproduced at the same time are T1, T3, T
5. . . It becomes like. Reproduction is performed with the rotation of the information disk 1, and tracks T1, T3, T5. . . From tracks T2, T4, T6. . . , And tracks T3, T5, T7. . . When the beginning of the track is reached, a track jump is performed to advance the playback track. At this time, the information disc 1 continues to rotate during the track jump, and the tracks T7, T9,
Since the unreproduced area remains after passing the head of T11 ..., only three track jumps are performed, and the reproduction is resumed from the middle of the tracks T6, T8, T10 .... Similarly, when the interval between tracks to be reproduced is 3 or more, reproduction is performed, and the above-described reproduction process is continuously repeated.

Next, a description will be given of a method of controlling the interval between reproduction tracks by the control means 8 having the reproduction track interval changing means 8a. When data is recorded by the CLV method, the data recording capacity per revolution of the information disc 1 is proportional to the radial position of the track. When data is recorded by the ZCLV method, the linear velocity differs for each defined section of the information disk 1, but the data capacity per one rotation of the disk is proportional to the linear velocity of each section and the radial position on the information disk 1. . In the case of ZCAV, the capacity per one rotation of the disc is different for each section defined by the format of the information disc 1, but in any case, the data capacity is generally larger near the outer circumference than near the inner circumference of the information disc 1. It is getting bigger.

For example, if the recording capacity of data is doubled near the innermost circumference and the outermost circumference of the information disk 1, the data capacity reproduced during one reproduction cycle is also doubled. Are required to be twice as large as the data aligning memory 9 for arranging the data in order. For example, using the conventional method, as shown in FIG. 5, the number of simultaneously reproduced tracks is fixed at 3, the track interval is fixed at 3, and the outermost data recording capacity is twice the innermost data recording capacity. , The data recording capacity per revolution of the innermost circumference is 1 KBy
If te is used, the minimum required buffer memory capacity can be calculated as follows (where Nb is the number of light beams (the number of simultaneously reproduced tracks), and Ng is the interval between light beams (track interval). ), Nr is the number of tracks reproduced during the reproduction cycle).

Nr = Nb · Ng−1 From this equation, the number of tracks reproduced in one reproduction cycle is:
When 3 × 3-1 = 8, a track jump is performed after one rotation, and immediately after reading of data of the next track is started, it is determined that data that has not yet been read remains in the data alignment memory. In consideration of this, it is considered that a buffer capacity twice as large as this is secured. Further, the data capacity per one rotation of the disk is doubled in the vicinity of the outermost periphery.
At least a data buffer capacity of 2 × 2 = 32 Kbytes is required.

On the other hand, in the present embodiment, the number of simultaneously reproduced tracks is fixed at 3, while the track interval is 1, and
It is made variable by 2 and 3. Considering the case where the data recording capacity of the outermost circumference is twice the data recording capacity of the innermost circumference and the data recording capacity per one rotation of the innermost circumference is 1 KByte, one track interval is 1, 2, 3, and 1 The reproduction data capacity during the reproduction cycle is 2, 5,.
8 KB.

In the innermost circumference, by setting the track interval to the maximum of 3, the capacity of the data alignment buffer memory 9 can be set to 8 × 2 = 16 Kbytes. In the outermost circumference, the track interval is set to 3 at the maximum in the first reproduction cycle, and 8
× 2 = 16 KB data alignment buffer memory 9
In the next reproduction cycle, the reproduction is stopped because there is no free area in the data alignment buffer memory 9. Since the free space that the data reading means 11 has read during one rotation of the disk is secured, the maximum track size within a range where the reproduced data capacity per cycle does not exceed the free capacity of the data alignment buffer memory 9 is obtained. The interval 2 or 1 may be selected.

As another method, the following method may be used. That is, at the innermost circumference where the data capacity per one rotation of the disk is 1 KByte, the track interval is set to a maximum of 3, and a double buffer capacity is secured in consideration of the remaining data that has not been read. In this case, 8 × 2
× 1 = 16 KB data alignment buffer memory 9
Of capacity.

On the other hand, at the outermost circumference, the track interval is set to a minimum of 1
And As a result, the number of tracks Nr reproduced during one reproduction cycle is 3 × 1-1 = 2. If a buffer capacity twice as large as this is secured in consideration of the remaining data that has not been read, the disk Data capacity per rotation is 2KB
Since the size is 2 te, the capacity of the data alignment buffer memory 9 is 2 × 2 × 2 = 8 Kbytes.

Further, the track interval is set to 2 in the middle circumference. As a result, the number of tracks Nr reproduced during one reproduction cycle is 3 × 2-1 = 5, and if a buffer capacity twice as large as this is secured in consideration of the remaining data that has not been read, the disk 1.5KB data capacity per rotation
5 x 2 x 1.5 = 15 KB
Of the buffer memory 9 for data alignment.

In any case, the required capacity of the data buffer is about 16 Kbytes, which is about half that of the case where the track pitch is not changed. In addition,
If the reading speed of the data reading means 11 becomes slow for some reason and the remaining capacity of the data alignment memory 9 becomes small, the data capacity to be reproduced during one reproduction cycle cannot be secured, and the reproduction must be stopped. No longer. Therefore, even in such a case, it is preferable to change the interval between the reproduction tracks to a smaller value so that the data capacity to be reproduced during one reproduction cycle is smaller than the remaining capacity of the data alignment memory 9. Conversely, when the remaining capacity of the data alignment memory 9 is sufficiently large, the interval between the reproduction tracks is set to the maximum possible number, whereby the data can be reproduced efficiently.

In this embodiment, a case has been described in which the read head 3 is provided with a mechanism for physically changing the interval between a plurality of reproduction tracks. However, the present invention is not limited to this. Needless to say, it is also possible to provide a large number of read heads 3 in one and input only signals from the read heads 3 from a corresponding number of track intervals. (Embodiment 2) A second embodiment described in claims 2 to 4 and claim 6 of the present invention will be described below with reference to FIGS. It is to be noted that components having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 3 is a block diagram of a multi-track disk reproducing apparatus according to a second embodiment of the present invention. The effective number of effective tracks to be reproduced in parallel (the number of effective simultaneous reproduction tracks) is adjusted in accordance with the remaining capacity, the storage capacity per track of the information disc of the currently reproduced track, and the interval between tracks to be reproduced in parallel. Track number changing means 8b is provided. In this embodiment, the case where the interval between tracks to be reproduced in parallel is fixed is described first.

The flow of the data reproducing operation is almost the same as that of the above-described embodiment, but the intervals between tracks to be reproduced in parallel are fixed. The operation of controlling the number of tracks to be read by the control means 8 having the effective track number changing means 8b in the multi-track disc reproducing apparatus will be described. When the information disc 1 is recorded at a constant linear velocity and the data amount per track differs depending on the radial position on the information disc 1, first, when data reproduction is started, the head data of each track is recorded on the disc. The address is calculated, and the data capacity of each track is calculated from the difference between the start address values of each track. If the data of the immediately preceding track has already been read, the data capacity per track hardly changes with a difference of several tracks.
It can be based on data capacity per rotation,
Calculate the approximate data capacity per disk rotation based on the linear velocity of the information disk 1 and the number of tracks from the innermost circumference,
This can be used as a reference.

When the free area of the data alignment memory 9 is smaller than the total data capacity per one reproduction cycle, the number of effective tracks to be reproduced in parallel is set to a number smaller than the maximum number of tracks that can be reproduced in parallel. Then, the reproduction operation of the data of the track that cannot be written to the data alignment memory 9 is stopped. As a method of changing the effective number of tracks to be reproduced in parallel, the reproduction operation of the read head 3 may be stopped to change the number of tracks for outputting a reproduction signal, or the operation of the head amplifier 5 may be stopped and the digital The number of signals input in parallel to the signal processing circuit 7 may be changed, or the operation of the digital signal processing circuit 7 may be stopped to change the number of data output to the memory controller 10 in parallel. The number of tracks to be written in parallel to the data alignment memory 9 may be changed by the memory controller 10, and before the track jump, the free space of the data alignment memory 9 is compared with the data capacity per disk rotation, The number of overlapping tracks may be changed by causing the read head 3 to make a track jump so as to overlap the already reproduced track.

For example, using the conventional method, as shown in FIG. 5, the number of simultaneously reproduced tracks is fixed at 3 and the track interval is 3, and the outermost data recording capacity is twice the innermost data recording capacity. If the data recording capacity per rotation at the innermost circumference is 1 KByte, the minimum necessary buffer memory capacity can be calculated as follows (where N
b is the number of light beams (the number of simultaneously reproduced tracks), Ng is the interval between the light beams (track interval), and Nr is the number of reproduced tracks during the reproduction cycle.)

Nr = Nb · Ng−1 From this equation, the number of tracks reproduced during one reproduction cycle is 3 × 3-1 = 8, a track jump is performed after one rotation, and the data of the next track is immediately obtained. When data reading is started, the buffer capacity is doubled in consideration of the fact that unread data still remains in the data alignment memory. Since the data capacity is doubled, 8 × 2 ×
At least a data buffer capacity of 2 = 32 KB is required.

On the other hand, as schematically shown in FIG. 4, in the present embodiment, the track interval is fixed at 3, while the number of effective simultaneous reproduction tracks is varied by 1, 2, and 3. Considering the case where the outermost data recording capacity is twice the innermost data recording capacity and the innermost data recording capacity per rotation is 1 KByte, the effective number of simultaneous playback tracks is 1, 2 , 3, the reproduction data capacity during one reproduction cycle is
2, 5, and 8 Kbytes.

At the innermost circumference, by setting the maximum number of effective simultaneous reproduction tracks to 3, the capacity of the buffer memory 9 for data alignment can be reduced to 8 × 2 = 16 Kbytes. Also,
In the outermost circumference, the number of effective simultaneous reproduction tracks is set to a maximum of 3 in the first reproduction cycle, and all the capacity of the data alignment buffer memory 9 of 8 × 2 = 16 Kbytes is used. In response to the,
Since a free space is created in the data alignment buffer memory 9, the free space of the data alignment buffer memory 9 is reduced by one.
The number of effective simultaneously reproducible tracks is changed from 1 to 3 in accordance with the data capacity per rotation so that the data capacity during one reproduction cycle is kept below the free capacity of the buffer memory 9 for data alignment. What is necessary is to control.

As another method, the following method may be used. That is, in the innermost circumference where the data capacity per one rotation of the disk is 1 KByte, the number of effective simultaneous reproduction tracks is set to a maximum of 3, and the buffer capacity is doubled in consideration of the remaining data that has not been read. . In this case, the data capacity per one rotation of the disk is 1 KByte.
Because of e, the capacity of the data alignment buffer memory 9 of 8 × 2 × 1 = 16 Kbytes is sufficient.

On the other hand, on the outermost circumference, the number of effective simultaneous reproduction tracks is set to one. As a result, the number of tracks Nr reproduced during one reproduction cycle is 1 × 3-1 = 2, and if a buffer capacity twice as large as this is secured in consideration of the remaining data that has not been read, the disk Since the data capacity per rotation is 2 Kbytes, the capacity of the data alignment buffer memory 9 of 2 × 2 × 2 = 8 Kbytes is sufficient.

Furthermore, by setting the number of effective simultaneous reproduction tracks to 2 in the middle circumference, the number of tracks Nr reproduced during one reproduction cycle is 2 × 3-1 = 5, and the data that has not been read When the double buffer capacity is secured in consideration of the rest, the data capacity per one rotation of the disk is 1.
5 × 2 × 1.5 = 15 KB when 5 KB is assumed
The capacity of the data alignment buffer memory 9 of te is sufficient.

In either case, the required capacity of the data buffer is only about 16 KBytes, which is about half of the case where the number of effective simultaneous reproduction tracks is not changed. Furthermore, it is also possible to combine with the method of changing the interval between the reproduction tracks described in the first embodiment. For example, when the number of effective simultaneous reproduction tracks is variable in 1, 2, and 3, and the track interval is also variable in 1, 2, and 3,
The number of playback tracks during one playback cycle is 1, 2, 3, 5, 8
, And more fine-grained control becomes possible. In this case, the playback speed is faster and
If the data capacity during the reproduction cycle is controlled to be equal to or less than the free space of the data alignment buffer memory 9, the same effect can be obtained, and at the same time, the decrease in the actual reproduction speed can be minimized.

In each of the above embodiments, the information disk 1 has a case where the tracks are spirally recorded. However, the present invention is not limited to this.
It goes without saying that the present invention can also be applied to a track in which tracks are recorded concentrically.

[0042]

As described above, according to the multi-track disk reproducing method of the present invention, data alignment is achieved by changing the interval between tracks to be reproduced in parallel and by changing the number of effective tracks to be reproduced in parallel. Buffer memory capacity can be kept to the minimum necessary, the buffer memory for data alignment can be used to the maximum even in a portion where the recording capacity per disk rotation is small, and the remaining capacity of the buffer memory for data alignment is reduced. In such a case, the operation of storing useless reproduction track data is not performed, so that the power consumption of the system can be minimized. Further, according to the multi-track disc reproducing apparatus of the present invention, the above-described multi-track disc reproducing method can be favorably performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a multi-track disc reproducing apparatus according to a first embodiment of the present invention;

FIG. 2 is an enlarged view of a track of a CD-ROM disk used in the multi-track disk reproducing method according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a multi-track disc reproducing apparatus according to a second embodiment of the present invention;

FIG. 4 is an enlarged view of a track of a CD-ROM disc used in a multi-track disc reproducing method according to a second embodiment of the present invention.

FIG. 5 is an enlarged view of a track of a CD-ROM disk used in a conventional multi-track disk reproducing method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 information disk 2 disk drive 3 read head (signal reproducing means) 4 read head drive 5 head amplifier 6 servo circuit 7 digital signal processing circuit (data converting means) 8 control means 8a reproduction track interval changing means 8b effective track number change Means 9 Data alignment memory 10 Memory controller 11 Data reading means (data output means)

Claims (6)

[Claims] A plurality of tracks are spirally or concentrically formed on a recording surface, and are recorded on an information disk such that the data recording capacity of a track per rotation changes according to a radial position. In a multi-track disc reproducing apparatus for reproducing signals of a plurality of tracks in parallel at intervals, a reproducing track interval varying means for changing an interval between tracks to be reproduced in parallel, and reproducing signals of a plurality of tracks from an information disk in parallel A signal reproducing means, a data converting means for converting each of the plurality of read signals of the plurality of tracks into digital data and outputting the digital data, and storing the data outputted in parallel and arranging them in the order of addresses on the information disk For aligning data and outputting the aligned and valid data to the outside of the disc reproducing apparatus Data output means for changing the interval between tracks to be reproduced in parallel according to the remaining capacity of the data alignment memory and the storage capacity of the currently reproduced track per rotation of the information disk. Multi-track disc playback device. 2. A plurality of tracks are formed spirally or concentrically on a recording surface, and are recorded on an information disk such that the data recording capacity of a track per rotation changes according to a radial position. In a multi-track disc reproducing apparatus that reproduces signals of a plurality of tracks in parallel at intervals, the intervals of tracks reproduced in parallel are arranged at a fixed interval, and the signals of a plurality of tracks are reproduced in parallel from an information disk. A signal reproducing means, a data converting means for converting each of the plurality of read signals of the plurality of tracks into digital data and outputting the digital data, and storing the data outputted in parallel and arranging them in the order of addresses on the information disk Memory for data alignment for
Data output means for outputting aligned and valid data to the outside of the disc reproducing apparatus; the remaining capacity of the data aligning memory and the information disc 1 of a track currently being reproduced;
Control means for changing the effective number of tracks to be reproduced in parallel according to the storage capacity per rotation and the interval between tracks to be reproduced in parallel. 3. The multi-track disc reproducing apparatus according to claim 1, wherein the tracks to be reproduced in parallel are adapted to the remaining capacity of the data alignment memory and the storage capacity of the currently reproduced track per rotation of the information disc. A multi-track disc reproducing apparatus characterized by changing the interval between the tracks and the number of effective tracks to be reproduced in parallel. 4. The multi-track disc reproducing apparatus according to claim 1, wherein the information disc is a CD-RO.
A multi-track disc reproducing apparatus, which is an M-standard disc, in which tracks are formed spirally and recorded at a constant linear velocity. 5. A plurality of tracks are formed spirally or concentrically on a recording surface, and are recorded on an information disk such that the data recording capacity of a track per rotation changes according to a radial position. The signals of a plurality of tracks are reproduced in parallel, the output read signals of the plurality of tracks are converted into digital data and output, and the data output in parallel is stored in a data alignment memory to store information. A multi-track disc reproducing method for arranging in order of addresses on a disc and outputting aligned valid data, wherein a remaining capacity of a data arranging memory and a storage capacity per one revolution of an information disc of a track currently being reproduced are determined. A multi-track disc reproducing method characterized by changing an interval between tracks to be reproduced in parallel by adapting the method. Law. 6. A plurality of tracks are formed spirally or concentrically on a recording surface, and are recorded on an information disk such that the data recording capacity of a track per rotation changes according to a radial position. The signals of a plurality of tracks are reproduced in parallel, the output read signals of the plurality of tracks are converted into digital data and output, and the data output in parallel is stored in a data alignment memory to store information. A multi-track disc reproducing method for arranging in order of addresses on a disc and outputting aligned valid data, wherein a remaining capacity of a data arranging memory and a storage capacity per one revolution of an information disc of a track currently being reproduced are determined. Multitrack disc playback characterized by adapting and changing the effective number of tracks to be played in parallel Method.