JP3929203B2 - Multitrack disc playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-track disc reproducing apparatus that reads data of a plurality of adjacent tracks on an information disc in parallel.
[0002]
[Prior art]
In recent years, disk reproducing apparatuses such as CD-ROM apparatuses have been required to have a high-speed reading function. As a method for realizing this, a multi-track disk reproducing apparatus that reads data on a plurality of adjacent tracks on a disk in parallel has been proposed. Yes.
Conventionally, when data is read out by a multi-track disc reproducing apparatus, one described in US Pat. No. 5,627,805 is known. In this method, data read from a plurality of tracks is first demodulated by EFM (8-14 conversion), then stored in a large-capacity buffer memory, arranged in accordance with the arrangement on the disk, and CIRC (cross) in order from the top data. -Interleaved Reed-Solomon code) decoding, and if ECC information is included, ECC correction is further performed on this buffer memory, and CIRC decoding and ECC are completed to ensure continuity with the top data. A method is employed in which the sorted data is output to the outside of the apparatus.
[0003]
In addition, a method has also been proposed in which CIRC decoding and C1 and C2 error correction are performed in parallel, and data with less redundancy after error correction of C1 and C2 is arranged on the buffer memory.
In these reading methods, the track reading operation will be described with reference to FIG. As can be seen from the enlarged view of the portion a of the CD-ROM disc as the information disc 1 shown in FIG. 3, the CD-ROM disc is formed with spiral tracks, and the tracks T1, T2, T3,. .. Are continuously connected to T2, T3, T4,... And the next track after one rotation of the disk.
[0004]
For example, in the case of reading three tracks at the same time, reading of the data of each track is started from the beginning of T1, T2, and T3, and when the data for one rotation is read, the three playback tracks are read by T2, T3, respectively. , Reach the beginning of T4. Next, in order to reproduce the data of the unread track, each reproduction track must be jumped to T4, T5 and T6.
[0005]
Therefore, in any of the methods, after reading data for one rotation of the disk, it is necessary to perform a track jump to advance the reproduction track and advance the reproduction track every rotation of the disk.
Further, since the buffer memory in the above example must arrange data in the order of the tracks and output the data to the outside of the apparatus in the order of the tracks, the storage capacity per rotation of the disk is multiplied by the number of tracks that can be reproduced simultaneously. Considering that the data of the previous track still remains in the buffer memory when the playback track is advanced (track jump), it is practically twice as large as this. Is required.
[0006]
[Problems to be solved by the invention]
However, in the conventional disk reproducing apparatus, in the case of a disk recorded at a constant linear velocity, such as a CD-ROM, the storage capacity per one rotation of the disk varies between the inner peripheral part and the outer peripheral part on the disk. A buffer memory must be prepared in accordance with the maximum storage capacity per revolution at the outer periphery of a disk having a large storage capacity per revolution, and the buffer memory is not fully utilized when reading data near the inner circumference. There is a problem.
[0007]
Also, depending on the output speed of data to the outside of the device, the buffer capacity becomes full, and even if data of multiple tracks is reproduced simultaneously, a wasteful operation is performed, and extra power is consumed. There is.
An object of the present invention is to provide a multi-track disk reproducing apparatus that can sufficiently and effectively utilize the memory capacity of a buffer memory.
[0008]
[Means for Solving the Problems]
The multi-track disc reproducing apparatus of the present invention is an information disc recorded with a plurality of tracks spirally or concentrically formed on the recording surface and recorded so that the data recording capacity of the track per rotation changes depending on the radial position. In a multi-track disc reproducing apparatus that reproduces signals of a plurality of adjacent tracks in parallel, a signal reproducing unit that reproduces signals of a plurality of adjacent tracks in parallel from the information disc, and a read signal of the plurality of tracks from the signal reproducing unit Data conversion means for converting each of them into digital data and outputting; data alignment means for aligning the data output in parallel in the order of addresses on the information disk and storing them in the data alignment memory; and alignment of the data alignment memory Reading means for reading out the completed data and the rest of the data alignment memory Depending on the amount and the storage capacity per rotation the information disc 1 of the current track, is provided with a control means for controlling so as to change the number of tracks to be reproduced in parallel.
[0009]
According to the present invention, the memory capacity of the data alignment memory can be set to the minimum necessary level, and the data alignment buffer memory prepared even in the inner periphery of the disk recorded at a constant linear velocity can be utilized to the maximum extent. After the data alignment buffer is full, power consumption can be reduced by not reproducing unnecessary track data.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the multitrack disk reproducing apparatus according to the first aspect of the present invention, a plurality of tracks are spirally or concentrically formed on the recording surface, and the data recording capacity of the track per one rotation changes depending on the radial position. In a multi-track disc reproducing apparatus for reproducing the signals of a plurality of adjacent tracks on the recorded information disc in parallel, the signal reproducing means for reproducing the signals of the plurality of adjacent tracks from the information disc in parallel, and the signal reproducing means Data conversion means for converting each of read signals of a plurality of tracks into digital data and outputting the data; data alignment means for aligning the data output in parallel in the order of addresses on the information disk and storing them in a data alignment memory; and Read means for reading the aligned data in the data alignment memory, and the data alignment A multi-track disc playback apparatus provided with control means for controlling the number of tracks to be played back in parallel according to the remaining capacity of the memory for storage and the storage capacity per rotation of the information disc currently being played back; Since the number of effective tracks to be reproduced in parallel is changed according to the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disk of the currently reproduced track, the data alignment memory After the data alignment memory is full, the memory capacity can be reduced to the minimum required, and the data alignment memory prepared at the inner periphery of the disc recorded at a constant linear velocity can be used to the maximum. The power consumption can be reduced by not reproducing unnecessary track data.
[0011]
According to a second aspect of the present invention, the signal reproducing means includes a reproducing head for reproducing the signals of a plurality of adjacent tracks on the information disk, and a signal read by the reproducing head to an appropriate amplitude. 2. A multi-track disk reproducing apparatus according to claim 1, further comprising a head amplifier for amplifying, wherein the control means is configured to change the number of tracks to be reproduced in parallel by stopping the signal reading operation of the reproducing head of the designated track. Since the number of effective tracks to be reproduced in parallel is changed according to the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disk of the currently reproduced track, the data alignment memory Can be made the minimum required memory capacity, and the data prepared at the inner circumference of the disc recorded with a constant linear velocity With a memory for the column can maximize, after the data alignment memory is full it is possible to reduce the power consumption by not reproduce the data of unwanted track.
[0012]
According to a third aspect of the present invention, the signal reproducing means includes a reproducing head for reproducing the signals of a plurality of adjacent tracks on the information disk, and a signal read by the reproducing head to an appropriate amplitude. 2. The multi-track disk reproducing apparatus according to claim 1, further comprising a head amplifier for amplifying, wherein the control means is configured to change the number of tracks to be reproduced in parallel by stopping signal output of the reproducing head of the designated track. Since 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 per rotation of the information disk of the track currently being reproduced, The memory capacity can be reduced to the minimum necessary level, and the data alignment mem- ber prepared on the inner circumference of the disc recorded at a constant linear velocity is also available. With a Li can maximize, after the data alignment memory is full it is possible to reduce the power consumption by not reproduce the data of unwanted track.
[0013]
According to a fourth aspect of the present invention, there is provided the multi-track disc reproducing apparatus, wherein the control means is configured to change the number of tracks to be reproduced in parallel by changing the number of tracks to be converted and output by the data converting means in parallel. The multi-track disc playback apparatus according to Item 1, wherein the tracks to be played back in parallel according to the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disc of the track currently being played back Since the number is changed, the memory capacity of the data alignment memory can be reduced to the minimum necessary level, and the data alignment memory prepared at the inner periphery of the disk recorded at a constant linear velocity can be utilized to the maximum extent. After the data alignment memory is full, power consumption can be reduced by not reproducing unnecessary track data.
[0014]
The multi-track disk reproducing apparatus according to claim 5 of the present invention is configured such that the control means changes the number of tracks to be reproduced in parallel by changing the number of tracks of data to be written in parallel to the data alignment memory. The number of tracks to be played back in parallel according to the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disk of the track currently being played back is provided. Therefore, the memory capacity of the data alignment memory can be minimized, and the data alignment memory prepared at the inner periphery of the disk recorded at a constant linear velocity can be utilized to the maximum. .
[0015]
The multi-track disc playback apparatus according to claim 6 of the present invention is configured such that the control means changes the number of tracks to be played back in parallel by changing the number of read tracks of the signal playback means overlapping the already played tracks. The multi-track disk playback apparatus according to claim 1, wherein the multi-track disk playback apparatus is configured to perform effective parallel playback according to the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disk of the track currently being played back. Since the number of tracks to be changed is changed, the memory capacity of the data alignment memory can be reduced to the minimum necessary level, and the data alignment memory prepared at the inner periphery of the disk recorded at a constant linear velocity can be utilized to the maximum. be able to.
[0016]
According to a seventh aspect of the present invention, there is provided the multi-track disk reproducing apparatus according to the first to third aspects, wherein the information disk is a CD-ROM standard disk in which tracks are spirally formed and data is recorded at a constant linear velocity. 6. The multi-track disc playback device according to any one of claims 6 to 6, wherein the multi-track disc playback device according to any one of claims 6 and 6 is arranged in an effective parallel according to the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disc of the track currently being played back. Since the number of tracks to be played is changed, the memory capacity of the data alignment memory can be reduced to the minimum necessary level, and the data alignment memory prepared at the inner periphery of the disk recorded at a constant linear velocity can be utilized to the maximum. In addition, power consumption can be reduced by not reproducing unnecessary track data after the data alignment memory is full.
[0017]
The multi-track disc playback apparatus of the present invention will be described below based on specific embodiments.
(Embodiment 1)
In the multitrack disk reproducing apparatus of the first embodiment shown in FIG. 1, a plurality of tracks are formed on the recording surface in a spiral or concentric manner, as in the conventional example, and the track data per rotation is determined by the radial position. A multi-track disc reproducing apparatus for reproducing in parallel a plurality of adjacent tracks on the information disc 1 recorded so that the recording capacity changes, and a signal for reproducing in parallel a plurality of adjacent tracks from the information disc 1 A reproducing means 2, a digital signal processing circuit 3 as a data converting means for converting each of read signals of a plurality of tracks from the signal reproducing means 2 into digital data and outputting the digital data; Data aligning means 5 for sequentially storing the data in a data aligning memory (buffer memory) 4 and for data aligning The data reading means 6 as a reading means for reading the aligned data of the memory 4 and the remaining capacity of the data alignment memory 4 and the storage capacity per rotation of the information disk 1 of the track currently being reproduced are arranged in parallel. Unlike the conventional example, the control means 7 for controlling the number of tracks to be reproduced is provided.
[0018]
Each configuration of the multi-track disc reproducing apparatus will be described more specifically.
Examples of the information disk 1 include an optical disk, a magnetic disk, and a magneto-optical disk. Here, the information disk 1 is an optical disk. The disk drive device 8 is a motor that rotates the information disk 1 at a predetermined speed.
[0019]
The signal reproducing means 2 includes a reading head unit 9, a reading head unit driving device 10, a servo circuit 11, and a head amplifier unit 12.
The read head unit 9 corresponds to, for example, an optical pickup in an optical disk device or a magneto-optical disk device, and corresponds to a magnetic head in a magnetic disk device. Here, the read head unit 9 is shown in FIG. , A plurality of optical pickups 9a each composed of a pair of light emitting elements and light receiving elements, which are installed so as to be movable in the radial direction of the information disc 1, and data on a plurality of tracks adjacent to the information disc 1 Simultaneously reading and reproducing in parallel with the pickup 9a. FIG. 2 shows a state in which, for example, tracks T2 to T5 among a plurality of tracks T1 to Tn of the information disk 1 are simultaneously read and reproduced in parallel by four optical pickups 9a.
[0020]
The read head unit driving device 10 drives the read head unit 9 in the radial direction to move to a target track. The servo circuit 11 performs focus control of the optical pickup 9a and servo control in the tracking direction when the reading head unit 7 is constituted by the optical pickup 9a.
As shown in FIG. 2, the head amplifier unit 12 is composed of a plurality of head amplifiers so as to amplify the signals reproduced in parallel from the reading head unit 9, convert them into signals of appropriate sizes, and output them. .
[0021]
As shown in FIG. 1, the digital signal processing circuit 3 converts signals output in parallel from the head amplifier unit 12 into digital data, and performs demodulation and decoding in parallel when modulation or encoding is performed. Output to.
The data alignment means 5 is composed of a memory controller 13 that sequentially aligns data output in parallel from the digital signal processing circuit 3 in the data alignment memory 4 in order from the top of the data.
[0022]
The data reading means 6 reads the data in the same order as the track arrangement of the information disk 1 at a speed slower than the total speed at which the data reproduced in parallel is reproduced, and outputs the data outside the apparatus.
The control means 7 is a controller such as a central processing unit (CPU), for example, a disk drive device 8, a read head drive device 9, a servo circuit 11, a digital signal processing circuit 3, a memory controller 13, The data reading means 6 is controlled.
[0023]
Here, the actual reading operation of the multi-track disc reproducing apparatus will be described below.
Signals read in parallel from the read head unit 9 are converted into an appropriate amplitude by the head amplifier unit 12 and input to the digital signal processing circuit 3. The digital signal processing circuit 3 performs necessary processing such as conversion, demodulation, and decoding of signals input in parallel into digital data, and outputs the digital data to the memory controller 13. The memory controller 13 arranges the data output from the digital signal processing circuit 3 in the data arrangement memory 4 in the data arrangement order and temporarily stores the data. The data reading means 6 sequentially outputs the data in the data alignment memory 4.
[0024]
After the reproduction of the data of one rotation of the information disk 1 is completed, the reading head unit driving device 10 and the servo circuit 11 are driven by the instruction of the control means 7 to advance the reproduction track. When the information disc 1 is spirally formed, the optical pickup 9a for reproducing the innermost reproduction track among the plurality of reproduction tracks is used as the reproduced data. It is difficult to move the signal reproducing means 2 so as to be connected.
[0025]
Therefore, preferably, the optical pickup 9a for reproducing the innermost track is moved to the outermost track among the read tracks so that the plurality of optical pickups 9a overlap the already read track. Then, the signal reproducing means 2 is moved, and reading is resumed immediately after the movement. The signal reproducing means 2 moved onto the reproduced track may start reproduction as it is and compare with the read data, or may overwrite the read data unconditionally. Alternatively, the reading operation or the data output operation may be stopped until unread data comes.
[0026]
The number of read tracks is controlled by the control means 7 as follows.
When the information disc 1 is recorded at a constant linear velocity and the amount of data per track differs depending on the location on the disc, first, when data playback is started, the address on the disc of the first data of each track is calculated. Then, the data capacity of each track is calculated from the difference between the start address values of the tracks. If the data of the previous track has already been read, the data capacity per track will hardly change with the difference of several tracks, so the data capacity per rotation of the outermost track that has been read may be used as a reference. It is also possible to calculate the approximate data capacity per disc rotation based on the linear velocity of the disc and the number of tracks from the innermost circumference, and use this as a reference.
[0027]
Further, when the information disk 1 is recorded at a constant angular velocity and the data capacity per rotation does not change depending on the position on the disk, the constant data capacity is used as a reference.
The control means 7 determines that the free space in the data alignment memory 4 is less than the value obtained by multiplying the data capacity per rotation of the disk by the number of tracks that can be reproduced simultaneously, and excluding the data capacity that overlaps the already read data. If it is larger, control is performed so that all playback tracks are enabled and playback is performed.
[0028]
The control means 7 determines that the free space in the data alignment memory 4 is less than the value obtained by multiplying the data capacity per rotation of the disk by the number of tracks that can be reproduced simultaneously, and excluding the data capacity that overlaps the already read data. If it is smaller, the number of effective tracks to be played back in parallel is set to be smaller than the maximum number of tracks that can be played back in parallel, and control is performed to stop the playback operation of data of tracks that cannot be written to the data alignment memory 4. To do.
[0029]
As described above, as a method of changing the number of effective tracks to be reproduced in parallel, the reproduction operation of the reading head unit 9 may be stopped and the number of tracks for outputting a reproduction signal may be changed, or the head amplifier unit 12 may be specified. The number of signals input in parallel to the digital signal processing circuit 3 may be changed by stopping the operation of the head amplifier, or the data output in parallel to the memory controller 13 by stopping the operation of the digital signal processing circuit 3 Or the number of tracks written in parallel to the data alignment memory 4 by the memory controller 13, and the free space of the data alignment memory 4 and one rotation of the disk before the track jump. Are compared, and the read head unit 9 is track-jumped so that it overlaps with a track that has already been reproduced. It may be varied the number of tracks.
[0030]
As a method for controlling the rotational speed of the disk, it is common to control at a constant angular velocity (CAV) when the disk is rotated at a high speed, but when a sufficient number of effective simultaneous reading tracks can be secured. , Linear CAV control (PCAV) that switches between constant linear velocity (CLV) and the disk divided into two sections and switches between constant linear velocity control and constant angular velocity control, and the disk is divided into a plurality of sections and controlled at a constant angular velocity for each section. Various methods are conceivable, such as a zone CAV (ZCAV), and a zone CLV (ZCLV) in which the disk is divided into a plurality of sections and the linear velocity is controlled at each section.
[0031]
In the above example, the disk is recorded with a constant linear velocity (CLV). However, as a recording method in which the data recording capacity per one rotation of the disk changes at a radial position on the disk, Partial CAV recording (PCAV) that divides the disc into two sections and switches between two types of recording methods, constant linear velocity and constant angular velocity, and zone CAV recording that divides the disc into a plurality of sections and records each section at a constant angular velocity (ZCAV), various methods such as zone CLV recording (ZCLV) in which a disc is divided into a plurality of sections and recorded at a constant linear velocity for each section are conceivable. If the capacity is known, it can be similarly implemented.
[0032]
Since it is configured as described above, the number of effective tracks to be reproduced in parallel is changed according to the remaining capacity of the data alignment memory 4 and the storage capacity of the information disk 1 of the currently reproduced track per revolution. The memory capacity of the alignment memory 4 can be reduced to the minimum necessary level, and the data alignment memory 4 prepared on the inner periphery of the disk recorded at a constant linear velocity can be utilized to the maximum extent. In a configuration in which the operation of some circuits is stopped for the number of tracks to be played back in parallel, power consumption is reduced by preventing playback of unnecessary track data after the data alignment memory is full. Can be planned.
[0033]
(Embodiment 2)
The multitrack disc playback apparatus according to the second embodiment of the present invention is obtained by specifically replacing the multitrack disc playback apparatus shown in FIG. 1 in the first embodiment with a CD-ROM device. In the following description, it is assumed that the data of six adjacent tracks can be reproduced simultaneously by the read head unit 9.
[0034]
The information disk 1 is a CD or CD-ROM standard disk, has a track formed on the recording surface in a spiral shape with a constant linear velocity, adds error correction information called C1 and C2, and uses an interleaving technique. The data is recorded.
The disk drive device 2 is a motor that rotates the information disk 1 at a predetermined speed. Specifically, various variations such as CLV control, CAV control, PCAV, ZCAV, and ZCLV can be employed. Then, it is assumed that the rotation of the information disk 1 is controlled so that the speed is 10 times per track on the outermost periphery of the disk by CAV control generally used in the current CD-ROM industry.
[0035]
The signal reproducing means 2 includes a reading head unit 9, a reading head unit driving device 10, a servo circuit 11, and a head amplifier unit 12.
The read head unit driving device 10 drives the read head unit 9 in the radial direction of the information disk 1 based on an instruction from the control unit 7 and moves the optical pickup 9a to a target track. The servo circuit 11 finely drives the lens of the pickup 9a in the tracking and focus directions, and holds the lens of the optical pickup 9a at a position optimal for signal reading. The read head unit 9 simultaneously reproduces data of six tracks adjacent to the recorded track by using six optical pickups 9a, and outputs six analog reproduction signals. The head amplifier unit 12 amplifies each signal output from the six optical pickups 9 a and outputs the amplified signal to the digital signal processing circuit 3.
[0036]
The digital signal processing circuit 3 converts each signal into digital data, performs EFM demodulation, deinterleaving, and C1, C2 error correction, and then outputs them to the memory controller 13. The memory controller 13 writes the data of each track in the data alignment memory 4 by arranging the data in the order of the tracks, and when the data is CD-ROM data, further performs an ECC error correction operation. The data reading means 6 reads the aligned data from the data alignment memory 4 and outputs it in the track arrangement order. The control means 7 is a controller circuit such as a CPU (Central Processing Unit), for example, a disk drive device 8, a read head drive device 10, a servo circuit 11, a digital signal processing circuit 3, a memory controller 13, and a data read means. 6 is controlled.
[0037]
Next, a method for controlling the number of read tracks will be described.
In the case of a CD / CD-ROM standard disc, since the linear velocity is recorded, the data capacity per revolution on the disc is about 20 kilobytes from the innermost circumference to the outermost circumference after C1 and C2 error correction ( kByte) to 50 kByte. In addition, since the address information is recorded on the disk, an accurate value can be calculated at the start of data reading from the head address information of each reproduction track.
[0038]
Here, in order to reproduce the data of six adjacent tracks in parallel and align them in the data alignment memory 4, in the conventional example, the innermost circumference 4 × 6 = 24 times speed and the outermost circumference 10 × 6 = 60. As the double speed, the data capacity per one rotation of the outermost circumference is 50 kByte × {6 (number of tracks) × 2 (for at least two rotations) −1 (one track on the inner circumference side)} = 50 × (6 × 2 According to -1), a data alignment memory having a memory capacity of 550 kbytes or more is required at the minimum, but this time is 256 kbytes.
[0039]
Consider a case where data reading is started near the innermost periphery and the data alignment memory 4 is empty. In this example, a method is adopted in which a reading track is set before the start position of the target data, and data reading is started immediately after the track jump is completed. In this method, it is not necessary to wait for the rotation until the data of the target address after the track jump comes, so that the reproduction can proceed more efficiently. In the multi-track disc playback device, the track jump must be performed every time reading of one rotation of data is completed, and the playback track must be advanced.
[0040]
When the innermost playback track is jumped within one rotation before the target playback start address and data playback starts immediately, the data capacity of the innermost playback track is uncertain and The capacity per rotation is 20 kbytes or less. For example, if you jump to a point where the data capacity of the innermost track is 10 kbytes, the data capacity of the 2nd to 6th tracks is almost constant and is about 20 kbytes near the inner circumference. The total capacity is 10 kilobytes + 20 kilobytes × 5 = 110 kilobytes. Therefore, a 110 kbyte memory is secured in the data alignment memory 4, and the data is read and aligned.
[0041]
The data after the second track is not continuous with the head data until just before the data alignment is completed, so only the data on the innermost track is the effective data that has been aligned. After the data for one rotation is read, the data on the second and subsequent tracks are all continuous with the top data, and the data on all tracks are valid data. The data reading means 6 outputs valid data to the outside of the disk playback device in the order of the tracks.
[0042]
When the data for one rotation is read, the playback track is advanced and playback of a new track is started. At this time, since the free area of the data alignment memory is 146 Kbytes or more, it is possible to proceed with data reproduction with all the reproduction tracks valid. At this time, since the disc continues to rotate during the track jump, the reproduction beam passes through the read final data position during the track jump. Therefore, the innermost reproduction beam is caused to jump so as to overlap the outermost track that has already been read so that data reproduction can be started immediately after the track jump. Therefore, when the playback track is advanced after reading the first rotation data, the innermost playback track plays back only the portion of the data that has passed during the track jump, and the actual data capacity is The total amount of data that is almost zero and can be read out by one rotation of the disk is 20 kilobytes × 5 = 100 kilobytes.
[0043]
Usually, the reading speed of the data reading means 6 is sufficiently faster than the sum of the reproduction speeds, but the processing of the data output destination is slow, and the free space of the data alignment memory 4 may be reduced. In such a case, for example, if the free space of the data alignment memory 4 is only 70 kbytes immediately after the reproduction track is advanced, the data capacity per rotation is 20 kbytes, so 70/20 = 3.5. Therefore, the number of effective playback tracks is set to 5. The playback track on the innermost side plays back the portion of data that has passed during the track jump, so the data capacity is almost zero, the second to fourth tracks are assigned 20 kbytes, and the fifth track is assigned the remaining about 10 kbytes. The data reading means 6 reads the data from the data alignment memory 4 while the fifth reproduction track reads the data for 10 kbytes from the beginning, and if there is a free area, the data can be allocated to the fifth track.
[0044]
Thus, the reproduction can be advanced, and the reading of the data can be advanced at an average of 4 × 5 = 20 times speed near the innermost periphery.
Similarly, the number of effective playback tracks is determined when data playback is advanced near the outermost periphery. The data capacity of the innermost track immediately after the track jump is 0 to 50 KB near the outermost track. If jumping to a position where the data capacity of the innermost reproduction track is 25 kbytes, 6 tracks are set as effective reproduction tracks, 50 kbytes are allocated to the second to fifth tracks, and 31 kbytes are allocated to the sixth track. In the second and subsequent rotations, as in the case of the vicinity of the inner circumference, data reproduction is performed by setting the number of effective reproduction tracks according to the free space of the data alignment memory 4, but for data alignment every rotation. Until the memory 4 is full and the data for one rotation is read, the data reading means cannot read the data after the second track, and the data can be read only every other rotation. The data reading speed is approximately 10 × 5/2 = 25 times or higher.
[0045]
Thus, since the maximum data reproduction speed is limited by the capacity of the data alignment memory 4, when reproducing data near the outer periphery, the total data capacity per rotation is about the capacity of the data alignment memory 4. Similarly, reading can be performed at an average speed of about 25 times by limiting to 1/2. Specifically, the number of effective reproduction tracks is determined as follows.
[0046]
When the total data capacity per rotation is limited to 128 kbytes, which is 1/2 of the capacity of the data alignment memory 4, the following is performed. Near the outermost periphery, the data capacity of the first track is 0 to 50 kByte, and the second and third tracks are 50 kByte. Accordingly, when the data capacity of the first track is less than 28 kByte, the number of effective playback tracks is set to 4, and when the data capacity is more than 28 kByte, the number of effective playback tracks is set to 3. For example, if the data capacity of the first track is 25 kbytes, the second and third tracks are 50 kbytes, the fourth track is 3 kbytes, and if the first track is 50 kbytes, the second track is 50 kbytes and the third track is 28 kbytes. Become. After that, the reproduction proceeds in the same manner. However, since the data alignment memory 4 is actually vacant for the time being, the read data of the outermost track is continuously written even if the free capacity becomes 128 kbytes or less. Read data. When the reproduction track is advanced, the free space of the data alignment memory 4 is in a range from 106 kbytes to 125 kbytes depending on how much data read means sends out the data of the first track. In the second and subsequent rotations, if playback tracks are allocated to all the remaining memory capacities of the data alignment memory 4 and playback is performed, data playback can proceed without greatly changing the number of effective playback tracks for each rotation. I can do it.
[0047]
The effective read track setting method is the same because the data capacity per rotation at a certain location on the disk does not change even if the disk rotation speed control method is changed to CAV, ZCAV, PCAV, ZCLV, CLV. Can be determined. The method for determining the number of effective reproduction tracks is not limited to this embodiment, and various methods for determining the number of effective reproduction tracks are possible according to the free space of the data alignment memory 4.
[0048]
【The invention's effect】
As described above, according to the multi-track disc reproducing apparatus of the present invention, a plurality of tracks are formed in a spiral shape or concentric shape on the recording surface, and the data recording capacity of the track per rotation changes depending on the radial position. In parallel, a signal reproducing means for reproducing the signals of a plurality of adjacent tracks from the recorded information disc in parallel; a data converting means for converting each of the read signals of the plurality of tracks from the signal reproducing means into digital data and outputting the digital data; Data aligning means for aligning the output data in the order of addresses on the information disk and storing them in the data aligning memory, reading means for reading the aligned data in the data aligning memory, and the rest of the data aligning memory Depending on the capacity and the storage capacity per rotation of the information disc of the currently playing track A multi-track disk playback device provided with a control means for controlling the number of tracks to be played back, and the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disk of the track currently being played back Therefore, the number of effective tracks to be reproduced in parallel is changed, so that the memory capacity of the data alignment memory can be reduced to the minimum necessary level, and it is also prepared at the inner periphery of the disc recorded at a constant linear velocity. In addition, the data alignment memory can be utilized to the maximum, and power consumption can be reduced by not reproducing unnecessary track data after the data alignment memory is full.
[0049]
Further, the signal reproducing means includes a reproducing head that reproduces signals of a plurality of adjacent tracks on the information disk, and a head amplifier that amplifies a signal read by the reproducing head to an appropriate amplitude, and the control means Stop the reading operation of the signal from the playback head of the specified track, stop the output of the signal from the playback head of the specified track, or change the number of tracks that the data conversion means converts in parallel. Even when the number of tracks to be reproduced in parallel is changed, the same effect as described above is obtained.
[0050]
Further, the control means changes the number of tracks to be reproduced in parallel by changing the number of tracks of data to be written in parallel to the data alignment memory, or sets the number of read tracks of the signal reproducing means overlapping with the already reproduced tracks. In the case of changing the number of tracks to be reproduced in parallel by changing the number of tracks, it is effective depending on the remaining capacity of the data alignment memory and the storage capacity per rotation of the information disk of the currently reproduced track. Since the number of tracks to be played back in parallel is changed, the memory capacity of the data alignment memory can be minimized, and the data alignment memory prepared at the inner periphery of the disc recorded at a constant linear velocity can be maximized. Limited use.
[0051]
Further, in the case of a multi-track disc reproducing apparatus in which the information disc is a CD-ROM standard disc in which data is recorded at a constant linear velocity with tracks formed in a spiral shape, the remaining capacity of the data alignment memory and the currently being reproduced Since the number of effective tracks to be reproduced in parallel is changed according to the storage capacity per revolution of the information disk of the track, the memory capacity of the data alignment memory can be minimized and the linear velocity is constant. In addition to being able to make the most of the data alignment memory prepared on the inner periphery of the disc recorded in step 1, the power consumption can be reduced by not reproducing unnecessary track data after the data alignment memory is full. Can be planned.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the configuration of a multi-track disc playback apparatus of the present invention
FIG. 2 is a block diagram showing the configuration of the main part of the signal reproducing means of the present invention.
FIG. 3 is an enlarged view of part a of the information disc.
[Explanation of symbols]
1 Information disc
2 Signal regeneration means
3 Digital signal processing circuit
4 Data alignment memory
5 Data alignment means
6 Data reading means
7 Control means
8 Disk drive
9 Read head
10 Read head unit driving device
11 Servo circuit
12 Head amplifier
13 Memory controller

Claims (7)

A plurality of tracks are formed in a spiral or concentric pattern on the recording surface, and the signals of adjacent tracks on the information disk recorded so that the data recording capacity of the track per rotation changes according to the radial position are reproduced in parallel. In a multi-track disc playback device that
Signal reproducing means for reproducing the signals of a plurality of adjacent tracks in parallel from the information disc;
Data conversion means for converting each of the read signals of the plurality of tracks from the signal reproduction means into digital data and outputting the digital data;
Data alignment means for aligning the data output in parallel with each other in the order of addresses on the information disk and storing the data in a data alignment memory;
Read means for reading the aligned data in the data alignment memory;
A multi-track disc provided with control means for controlling the number of 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 revolution of the information disc Playback device. The signal reproducing means includes a reproducing head that reproduces signals of a plurality of adjacent tracks on the information disc, and a head amplifier that amplifies the signal read by the reproducing head to an appropriate amplitude,
2. A multi-track disk reproducing apparatus according to claim 1, wherein the control means is configured to change the number of tracks to be reproduced in parallel by stopping the signal reading operation of the reproducing head of the designated track. The signal reproducing means includes a reproducing head that reproduces signals of a plurality of adjacent tracks on the information disc, and a head amplifier that amplifies the signal read by the reproducing head to an appropriate amplitude,
2. A multi-track disc reproducing apparatus according to claim 1, wherein the control means is configured to change the number of tracks to be reproduced in parallel by stopping the signal output of the reproducing head of the designated track. 2. A multi-track disc reproducing apparatus according to claim 1, wherein the control means is configured to change the number of tracks to be reproduced in parallel by changing the number of tracks to be converted and output by the data converting means in parallel. 2. The multi-track disc reproducing apparatus according to claim 1, wherein the control means is configured to change the number of tracks to be reproduced in parallel by changing the number of tracks of data to be written in parallel to the data alignment memory. 2. A multi-track disc reproducing apparatus according to claim 1, wherein the control means is configured to change the number of tracks to be reproduced in parallel by changing the number of read tracks of the signal reproducing means overlapping the already reproduced tracks. 7. The multi-track disk reproducing apparatus according to claim 1, wherein the information disk is a CD-ROM standard disk in which tracks are spirally formed and data is recorded at a constant linear velocity.

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