JPH08166853A - Recording medium reproducing device - Google Patents

Abstract

PURPOSE: To improve the access speed of the recording medium reproducing device which reads data out of a recording medium and reproduces them. CONSTITUTION: A head data storage memory 39 for storing head data of respective data files recorded on an optical disk 22 is prepared and the head data of the respective files are stored in this memory 39 by N blocks in a period other than a reproducing operation period corresponding to a data read request. When a request to read data out of a file on an external device is generated, the data begin to be read from a K(2<=K<=<=N+1)th block from the head of the file on the disk and are transferred to the external device after reading data of the file from the head out of the memory 39. The data read out of the disk are processed as specified and stored in a buffer memory 32 and then when they become able to be read out of the memory 32, the read of data from the memory 39 is quit at a (K-1)th block and data begin to be read out of the memory 32 and are transferred to the external device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium reproducing apparatus for reading and reproducing data from a recording medium such as an optical disk.

[0002]

2. Description of the Related Art Conventionally, in developing a recording medium reproducing apparatus such as an optical disk reproducing apparatus, various types of recording medium reproducing apparatuses have been used in order to shorten the access time from when a data read request is issued until data is actually output. Various technical approaches have been taken such as high performance servo mechanism and high speed data processing.

The reproducing operation of the optical disk reproducing apparatus will be described below with reference to FIG. 4 by taking the case of the optical disk reproducing apparatus as an example.

Optical disc 2 by optical pickup 1
The signal read from is supplied to the RF amplifier circuit 3. The RF amplifier circuit 3 extracts the focus error signal and the tracking error signal from the output of the pickup 1, supplies them to the focus / tracking control circuit 4, and supplies the amplified RF signal to the level slice / PLL circuit 5. The level slice / PLL circuit 5 generates a binarized signal from the supplied RF signal and simultaneously generates a PLL clock 6 from the RF signal. The binarized signal is supplied to the synchronization detection circuit 7 and the signal processing circuit 8.
The synchronization detection circuit 7 uses the PLL clock 6 to detect a periodic synchronization signal due to the format. The detected synchronization signal is supplied to the signal processing circuit 8 and the disc motor control circuit 9. The disk motor control circuit 9 extracts an error component by comparing the frequency and phase of the supplied reproduction synchronizing signal having a time-axis fluctuation with the frequency of the X'TAL system signal obtained by dividing the master clock 10. To the disk motor 11 and fed back to the disk motor 11. On the other hand, the signal processing circuit 8 decodes the binarized signal supplied from the level slice / PLL circuit 5 by using the PLL clock 6 and the synchronization signal from the synchronization detection circuit 7, and the data is stored in the buffer memory 12 by the PLL clock 6. Write. The memory control circuit 13 absorbs the fluctuation of the time axis by the disk motor 11 (jitter absorption) by reading the target data from the buffer memory 12 at the master clock 10. The read data is corrected by the signal processing circuit 8, and the buffer memory 12 is read again.
Transferred to and stored in. The data stored in the buffer memory 12 is interpolated by the data input / output circuit 14 according to the type and format of audio data, character data, etc.
After the filtering process is performed, the data is output to an external device.

The above-mentioned components are the system controller 15
Is controlled by System controller 1
When receiving a data read request from an external device, 5 controls the pickup feed motor 18 by giving a control command to the feed motor control circuit 17 to move the pickup 1 to a target position on the disc 2 and to transfer data from the disc 2. Is read out and the operation of each unit is controlled so as to reproduce and output through the series of signal processing.

As described above, in the optical disc reproducing apparatus, it is necessary to perform several steps of processing before receiving the data read request from the external apparatus and outputting the reproduced data to the external apparatus. It takes time. In particular, the time required to move the pickup to a desired position on the disc in response to a data read request is the greatest bottleneck in improving the access speed. Needless to say, various technical improvements have been made to increase the access speed. For example, a method of increasing the drive voltage of the disk motor in order to move the pickup to a target position quickly is given as an example. However, this method increases the mechanical load on the motor and increases the cost if a motor that can withstand the load is used. Further, even if the feed speed of the pickup and the operation speed of other signal processing systems are improved in this way, there is a limit to the shortening of the access time, and it has not reached a satisfactory level.

[0007]

As described above, the improvement of the access speed in the recording medium reproducing apparatus such as the optical disk reproducing apparatus is one of the possible problems.

The present invention is intended to solve such a problem, and an object of the present invention is to provide a recording medium reproducing apparatus which can realize a significant improvement in access speed without increasing mechanical load.

[0009]

In order to achieve the above object, the present invention provides a recording medium reproducing apparatus for reproducing a recording medium in which data is recorded in file units, in which data recorded in the recording medium is recorded. Reading means for reading, signal processing means for performing a predetermined signal processing on the data read by the reading means, and data processed by the signal processing means are temporarily stored before being transferred to an external device. First storage means for storing, and N from the head of the file that has been signal processed by the signal processing means (where N ≧ 1)
When a data read request for a certain file is issued from the second storage means for storing the data of the block and the external device, K (however, 2 ≦ 2) from the head of the corresponding file recorded on the recording medium is generated. At the same time as controlling to start data reading from the (K ≦ N + 1) th block, the data of the corresponding file stored in the second storage means is read from the beginning and transferred to the external device and read from the recording medium. If the output data is stored in the first storage means through the predetermined signal processing and can be read out from the first storage means, the data reading from the second storage means is performed in the K−1th order. Finally, the block is interrupted to start reading data from the first storage means,
And a control unit for controlling the read data to be transferred to the external device.

[0010]

In the present invention, for example, data is read from the recording medium during a period other than the reproducing operation period in response to a data read request from an external device, and the N blocks of data from the head of the file are stored in the second storage means. deep. When a data read request for a certain file is issued from the external device, the data read is started from the Kth block from the beginning of the file recorded on the recording medium. At the same time, the data of the corresponding file stored in the second storage means is read from the beginning and the transfer to the external device is started. If the data read from the recording medium is stored in the first storage means through a predetermined signal processing and becomes readable from the first storage means, the data reading from the second storage means is K−1th. Lastly, the block is interrupted, and instead of this, the data reading from the first storage means is started and transferred to the external device.

As described above, according to the present invention, in response to the data read request from the external device, the data is read from the recording medium and is output to the external device through the predetermined signal processing. Since the data previously stored in the storage means is read and transferred to the external device, the apparent access speed can be dramatically improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the arrangement of an optical disk reproducing apparatus as a recording medium reproducing apparatus according to an embodiment of the present invention.

In the figure, the signal read from the optical disk 22 by the optical pickup 21 is supplied to the RF amplifier circuit 23. The RF amplifier circuit 23 extracts the focus error signal and the tracking error signal from the output of the pickup 21, supplies them to the focus / tracking control circuit 24, and supplies the amplified RF signal to the level slice / PLL circuit 25. The level slice / PLL circuit 25 generates a binarized signal of the supplied RF signal and, at the same time, generates a PLL clock 26 from the RF signal. The binarized signal is supplied to the synchronization detection circuit 27 and the signal processing circuit 28. The synchronization detection circuit 27 is P
The LL clock 26 is used to detect a periodic sync signal due to the format. The detected synchronization signal is supplied to the signal processing circuit 28 and the disc motor control circuit 29. The disk motor control circuit 29 extracts the error component by comparing the frequency and the phase of the supplied reproduction synchronizing signal having a time axis fluctuation and the X'TAL system signal obtained by dividing the master clock 30. To the disk motor 31 and feed it back to the disk motor 31. On the other hand, the signal processing circuit 28 uses the PLL clock 26 and the synchronization signal from the synchronization detection circuit 27 to decode the binarized signal supplied from the level slice / PLL circuit 25, and the PLL clock 26 stores data in the buffer memory 32. Write. The memory control circuit 33 absorbs the fluctuation of the time axis due to the disk motor 31 (jitter absorption) by reading the target data from the buffer memory 32 with the master clock 30. The read data is corrected by the signal processing circuit 28, and again the buffer memory 3
2 and / or the head data storage memory 39. The data stored in the buffer memory 32 and / or the head data storage memory 39 is subjected to interpolation processing, filtering processing, etc. in the data input / output circuit 34 according to the type and format of audio data, character data, etc. Is output to.

Here, the head data storage memory 39
Is the data at the beginning of each data file recorded on the disk 22 (data that has been corrected)
Is provided as an area mainly for storing.

FIG. 2 is a diagram showing the structure of the head data storage memory 39. As shown in FIG.
In the table, M is the data (hereinafter referred to as head data) of the head portion (N (N ≧ 1) blocks from the head of the file) of each data file recorded on the disk 22.
Address information indicating the storage position on the memory 39 of the head data of each data file stored in the memory 39 and directory information of each data file stored in the memory 39 are registered. . That is, the head data storage memory 39 searches the address information of the head data of the target data file based on the directory information of each data file, and the head data of the target data file is retrieved from the memory 39 based on this address information. Can be read.

The storage of the head data in the head data storage memory 39 is automatically performed during a period other than the reproducing operation period in response to a data read request from an external device. For example, after the system is started, it is executed between the time the disk 22 is set and the time when the data read request is accepted, and the time when the reproduction operation for the data read request ends and the next data read request is generated. Also, after the system starts,
Data may be stored in the head data storage memory 39 with the highest priority, and no data read request may be accepted during this period. Further, while the corrected data is stored in the buffer memory 32 during the reproducing operation for the data read request, the head data is stored in the head data storage memory 39 at the same time, and the head data is stored only for the next and subsequent data read requests. May be effectively used.

A typical operation example of this embodiment will be described below on the assumption that the head data of all the data files recorded on the disk 22 is already stored in the head data storage memory 39.

When a data read request is issued from an external device, the system controller 35 moves the pickup 21 to a target position and starts reading data from the disk 22. At that time, the system controller 35 does not read the data from the beginning of the target data file, but performs control so as to start reading from the Kth (2 ≦ K ≦ N + 1) block from the beginning.

Further, the system controller 35 switches the switch 40 to the head data storage memory 39 side in response to the generation of the data read request, and at the same time, the memory control circuit 3
A control signal is output to 3 to read the head data of the target data file from the head data storage memory 39 and output it to the data input / output circuit 34. To read the head data from the head data storage memory 39, the address information indicating the position where the head data of the corresponding data file is stored is searched from the directory information of each data file, and the memory 39 is searched based on this address information. It is performed by reading the top data of the corresponding data file.

The reading of the head data from the head data storage memory 39 is performed by correcting the data of the Kth block read from the disk 22 by the pickup 21 in the buffer memory 32 through the predetermined signal processing. Is stored and is executed from the buffer memory 32 until output becomes possible.

For example, the system controller 35 monitors the number of blocks of the data file that has been read from the head data storage memory 39, and the value of this number of blocks is 1 from the value K of the block number at which reading from the disk 22 is started. When the value obtained by subtracting is reached, the switch 40 is switched to the side of the buffer memory 32, and a control signal is output to the memory control circuit 33 to perform control so as to read the Kth block data and thereafter from the buffer memory 32. .

Therefore, which number of blocks to read first from the disk 22 is optimally set, and when the reading of the (K-1) th block from the head data storage memory 39 is completed, the buffer memory 32 has already been read. By storing the Kth block, it is possible to continuously read the Kth and subsequent block data from the buffer memory 32 after the reading of the K−1th block from the head data storage memory 39 is completed. it can.

If the Kth block is not ready to be read at the time when the reading of the K-1th block is completed, the switch 40 is set to the buffer memory 32.
Just switch to the side and wait.

Thus, according to the optical disk reproducing apparatus of the present embodiment, the data of the head portion of each data file recorded on the disk 22 is stored in the head data storage memory 39 in the free time before the read request is issued. Immediately after the data read request is issued, the data of the head portion of the target data file is read from the head data storage memory 39, and thereafter, the disc 2 is processed through signal processing.
The apparent access speed can be greatly improved by switching the data and the output of the block in the middle of reproduction from No. 2. Therefore, the access time can be greatly reduced without a mechanical burden.

In this embodiment, after the value of the number of blocks of the data file which has been read from the head data storage memory 39 reaches K-1, the block data of the Kth and subsequent blocks are read from the buffer memory 32 next. Although it is configured to read data, the K + 1th and subsequent block data may be read from the buffer memory 32 after the value of the number of blocks of the data file that has been read from the head data storage memory 39 reaches K.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same components as those in FIG. 1 are designated by the same reference numerals.

The optical disk reproducing apparatus shown in the figure has a priority order judging circuit 41 for judging when the priority order (priority) of each data file recorded on the optical disk 22 is stored in the head data storage memory 39. It is a thing. Here, as a criterion for determining the priority of the data file,
There are various file sizes, access frequencies, etc., but in this embodiment, the smaller the file size, the higher the priority. Information regarding each data file is written in a specific area of the disk 22, and the size of the data file can be known by reading the information.

In this way, the apparatus of this embodiment having the priority determination circuit 41, when the number of data files recorded on the disk 22 is very large, for example, in the previous embodiment, as shown in FIG. Although the head data of each data file can be stored in the head data storage memory 39, it is suitable when there are M + 1 or more data files. The number of files that can store the top data in the top data storage memory 39 is desired to be as large as possible, but if the capacity of the top data storage memory 39 is expanded to fit an optical disk having a very large number of data files, the average number of files is increased. Memory 3 for many disks with
The utilization efficiency of 9 is lowered, and the total time for storing the head data in the head data storage memory 39 is very long. Under these circumstances, the number of files that can store the head data in the head data storage memory 39 is set to an average and appropriate number.

In the apparatus of this embodiment, when the system controller 35 tries to store the head data of a certain data file in the head data storage memory 39, the priority determination circuit 41 is activated and the size of the data file is changed. Etc. to determine the priority. Priority decision circuit 4
The priority of the data file determined by 1 is sent to the system controller 35. Here, the system controller 35 checks whether or not the number of head data items stored in the head data storage memory 39 has reached the maximum number M of head data items that can be stored in the memory 39, and the number of stored head data items is M. If the value has not reached, the head data of the data file read from the disk 22 this time is written in the head data storage memory 39. If the number of stored head data has reached the value of M, the system controller 35 has the lowest priority among the priorities of the data file groups in which the head data is already stored in the head data storage memory 39. The degree value is checked, and the priority of the newly determined data file is compared with the above-mentioned lowest priority. If the determination priority is higher than the lowest priority, the record of the first data of the lowest priority data file is deleted, and the first data of the data file read from the disk 22 this time is written in the first data storage memory 39. If the determination priority is equal to or lower than the lowest priority, the head data of the data file read from the optical disc 22 this time is not written. In this manner, by preferentially storing the head data of the data file having a high priority in the head data storage memory 39, the memory 39 having a limited number of stored head data can be efficiently and maximally used, and the total data can be totally utilized. Access speed can be improved.

In this embodiment, the file priority is determined according to the size of the file, but the number of times of access to each file in the past is checked for a certain period, and the file priority is determined based on this. You may

Further, as another embodiment of the present invention, a method is conceivable in which the capacity of each head data storage area in the head data storage memory 39 is changed according to the number of data files recorded on the optical disk. Information about the number of recording files is also recorded in a specific area of the optical disc, and the number of recording files can be known by reading this information. If each head data storage area is made small when the number of files is large, the head data of all files can be prepared in the head data storage memory 39 without changing the capacity of the memory 39. In addition, if the number of files is small and each head data storage area is large,
The reading of data from the optical disc can be started from a block further behind, the load on other circuits at the time of reproduction can be reduced, and the access time can be further shortened.

The present invention is not limited to a device for reproducing an optical disc, but may be a magnetic tape, a magnetic disc, or the like.
It is applicable to reproducing various recording media.

[0034]

As described above, according to the present invention, in response to a data read request from an external device, data can be read from a recording medium and output to the external device through predetermined signal processing. Since the data stored in advance in the second storage means is read as it is and transferred to the external device, the apparent access speed can be dramatically improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical disc reproducing apparatus according to an embodiment of the present invention.

2 is a diagram showing a configuration of a head data storage memory in the optical disc reproducing apparatus of FIG.

FIG. 3 is a block diagram showing the configuration of an optical disk reproducing device according to another embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional optical disc reproducing apparatus.

[Explanation of symbols]

21 ... Optical pickup, 22 ... Optical disk, 23 ...
RF amplifier circuit, 24 ... Focus / tracking control circuit, 25 ... Level slice / PLL circuit, 26 ... PL
L clock, 27 ... Synch detection circuit, 28 ... Signal processing circuit, 29 ... Disk motor control circuit, 30 ... Master clock, 31 ... Disk motor, 32 ... Buffer memory, 33 ... Memory control circuit, 34 ... Data input / output circuit,
35 ... System controller, 39 ... Head data storage memory, 40 ... Switch, 41 ... Priority determination circuit.

Claims (7)

[Claims] 1. A recording medium reproducing apparatus for reproducing a recording medium in which data is recorded in file units, and a reading means for reading the data recorded in the recording medium, and data read by the reading means. Signal processing means for performing a predetermined signal processing on the first and second storage means for temporarily storing data processed by the signal processing means before transfer to an external device, and a signal by the signal processing means. Second storage means for storing N (where N ≧ 1) blocks of data that have been processed, and the recording medium when a data read request for a certain file is issued from the external device. At the same time as controlling the data reading from the Kth (2 ≦ K ≦ N + 1) th block from the beginning of the corresponding file recorded in The data of the corresponding file stored in the column is read from the beginning and transferred to the external device, and the data read from the recording medium is stored in the first storage means through the predetermined signal processing and stored in the first storage means. If it becomes possible to read the data from the second storage means, the data reading from the second storage means is interrupted at the K-1th block last to start the data reading from the first storage means, and the read data is read. And a control means for controlling the transfer to the external device. 2. The recording medium reproducing apparatus according to claim 1, wherein data is read from the recording medium during a period other than a reproducing operation period in response to a data read request from the external device,
The recording medium reproducing apparatus further comprising a unit for writing N blocks of data from the head of the file into the second storage unit. 3. The recording medium reproducing apparatus according to claim 1, wherein data is read from the recording medium immediately after the recording medium is set in the reproducing apparatus, and N blocks from the head of the file are read into the second storage means. The recording medium reproducing apparatus, further comprising means for prohibiting acceptance of the data read request until the data is written and the necessary data is completely written. 4. The recording medium reproducing apparatus according to claim 1, further comprising priority determining means for determining a priority of a file to be stored in the second storage means according to a predetermined criterion. The second storage means stores N blocks of data from the file head of each of M (where M ≧ 2) files, and the control means determines by the priority determination means. For each of the top M files with high priority,
A recording medium reproducing apparatus characterized in that control is performed such that N blocks of data from the head of the file are preferentially stored in the second storage means. 5. The recording medium reproducing apparatus according to claim 4, wherein the priority determining unit determines the priority based on a file size. 6. The recording medium reproducing apparatus according to claim 4, wherein the priority determination unit determines the priority based on the number of times a data read request has occurred for each file in the past. Playback device. 7. The recording medium reproducing apparatus according to claim 1, wherein the second storage means stores N blocks of data from the file head of each of the plurality of files, and from the file head. A recording medium reproducing apparatus, wherein the size of each head data storage area for storing N blocks of data is variable according to the number of files recorded on the recording medium.