JP2002352503A - Optical disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk unit which carries out buffering suitable respectively for sequential data and repeatedly used data. SOLUTION: The CPU 170 of the optical disk unit 200, when it receives a request from a host 180 via an interface 150 to read out reproduction data, decides whether the requested reproduction data is sequential reproduction data or repeatedly used reproduction data based on address value of the requested reproduction data. When the reproduction data is sequential reproduction data, the CPU 170 controls a decoder so as to apply lookahead buffering to the reproduction data to a ring buffer of a buffer memory 160. When the reproduction data is repeatedly used reproduction data, the CPU 170 controls the decoder 140 so as to perform buffering to a cell buffer of the buffer memory 160.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly to an optical disk device that performs different buffering for sequential reproduced data and repeatedly used reproduced data.

[0002]

2. Description of the Related Art As a recording medium on which a moving image file comprising moving image data is recorded, a read-only DVD-ROM is used.
Video and Video-CD are known. When a moving image file is recorded on DVD-Video, the moving image file is arranged on DVD-Video so as to be suitable for sequential reading. And DV
Upon receiving a moving image data read request from a host such as a personal computer, the drive that reproduces the moving image file from the D-Video buffers the moving image data requested by the host. Next, pre-read buffering for automatically buffering the moving image data following is performed to improve the responsiveness to sequential reading.

Recently, magneto-optical disks and DVD-RAMs have been put into practical use as rewritable optical disks.
M is recorded, and the recorded moving image file is deleted.

[0004]

However, when recording and erasing of a moving image file on an optical disk are repeatedly performed,
Originally, moving image files to be sequentially arranged on the optical disk are randomly arranged.

[0005] Each moving image file is composed of management data and body data. Then, the management data of each moving image file is recorded collectively in a specific area of the optical disk, and the main body data is recorded in an area discrete from the specific area where the management data is recorded. In addition, in an iD-Photo or DVD-RAM, which is one of the magneto-optical disks that have recently been put to practical use, data is recorded in units of ECC blocks in which a plurality of sectors as units of user data are put together. Then, one ECC block may include management data of a plurality of moving image files, and when reading a plurality of moving image files from an optical disc, it is necessary to repeatedly read the ECC block in which the management data is recorded. is there.

In such a situation, data that is used repeatedly, such as management data, must be stored in a buffer memory in the drive for a long time. On the other hand, it is effective to perform pre-read buffering for data that is large in size and that is not repeatedly read, such as body data.

However, the host outputs a data read request including the start address of the request data and the length of the request data to the drive. Therefore, the drive determines whether the requested data is management data or main data. Cannot be recognized, and buffering suitable for the type of data cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide an optical disk apparatus that performs appropriate buffering for sequential data and data used repeatedly. It is to provide.

[0009]

According to the present invention, an optical disk apparatus reproduces a signal from an optical disk in response to a read data read request from a host, and outputs the reproduced data to the host. An optical pickup that irradiates a laser beam onto an optical disc and detects the reflected light, a decoding unit that decodes a reproduction signal reproduced from the optical disc by the optical pickup to generate reproduction data, and temporarily stores the reproduction data. Storage means for storing; storage means for storing reproduction data in the storage means; output means for reading the reproduction data requested from the host from the storage means and outputting to the host; and control means. When it is determined that the requested playback data is requested by the host, the playback data following the requested playback data Controls the storage unit so as to perform read-ahead buffering for storing prefetched in the storage means,
When it is determined that the reproduction data to be used repeatedly is requested by the host, the decoding unit is controlled to generate the requested reproduction data, and the reproduction data generated by the decoding unit is stored in the storage unit. To control the storage means.

Preferably, the control means searches the storage means in response to a read data read request from the host, and does not store the reproduced data in the storage means, and outputs the reproduced data output to the host by the output means. When reading of the reproduction data following the data is requested, it is determined that the reading of the sequential reproduction data is requested.

Preferably, the control means searches the storage means in response to a read request of the reproduction data from the host, and does not store the reproduction data in the storage means, and outputs the reproduction data outputted to the host by the output means. When reading of the reproduction data that is not continuous with the data is requested, it is determined that the reading of the repeatedly used reproduction data is requested.

[0012] Preferably, the control means may be arranged such that, based on an address value of the reproduction data on the optical disk, the reproduction data requested by the host is reproduction data following the reproduction data output to the host by the output means, or non-continuous reproduction. Determine whether it is data.

Preferably, the storage means includes a first storage area suitable for storing sequential reproduction data;
Second suitable for storing repeatedly used playback data
The storage means stores the sequential reproduction data in the first storage area and stores the repeatedly used reproduction data in the second storage area.

Preferably, the control means searches the storage means in response to a read request of the reproduction data from the host, and detects that the reproduction data requested by the host is stored in the first storage area, In addition, when there is a free area in the first storage area, it is determined that the reading of the sequential reproduction data has been requested.

[0015] Preferably, of the reproduction data stored in the first storage area, an address value indicating a position where the last reproduction data is stored is set as a first storage address value, and the reproduction value output to the host by the output means. Of the data, the address value indicating the position where the last reproduction data was stored is set to the second value.
When the first storage address value does not match the second storage address value, the control means determines that there is a free area in the first storage area.

Preferably, the control means controls the storage means so as to store the reproduction data in a free area by prefetch buffering.

Preferably, the control means performs the search in the order of the first storage area and the second storage area.

[0018]

Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

With reference to FIG. 1, a description will be given of a magneto-optical disk to which a signal is recorded and / or reproduced by the optical disk device according to the present invention. Magneto-optical disk 100
Is a plurality of bands B0 arranged concentrically in the radial direction.
B13. Each of the bands B0 to B13 is a test area T
It consists of SR and data area DR. Test area TSR
Are provided on the inner peripheral side of the data area DR. This test area TSR is used to optimize the power of laser light for recording and / or reproducing data in the data area DR of each of the bands B0 to B13.

FIG. 2 is a plan view showing a partial structure of each of the bands B0 to B13. Groove 1 and land 2
The magneto-optical disks 100 are alternately arranged in the radial direction DR1. Also, the groove 1 is used for the magneto-optical disk 100.
Land 3 of about 4 μm in tangential direction DR2
A, and the land 2 includes a groove 3B of about 4 μm in the tangential direction DR2. The land 3A and the groove 3B are in the radial direction D of the magneto-optical disk 100.
R2 formed adjacent to R1 in the tangential direction DR2.
Are formed at regular intervals.

The lands 3A and the grooves 3B are called "fine clock marks", and are referred to as "fine clock marks".
00 is a source for generating a reference clock CLK for recording and / or reproducing a signal at 00. The groove 1 and the land 2 are arranged spirally or concentrically.

Since signals are recorded and / or reproduced on a frame basis in each of the bands B0 to B13, each of the bands B0 to B13 includes a plurality of frames. That is, frames as recording units are arranged at equal intervals on the magneto-optical disk 100, and each frame is composed of 39 segments S0, S1, S2,..., S38.

The length of each segment is 532D
CB (Data Channel Bit), and at the beginning of each segment, a fine clock mark (F) indicating phase information of a clock for recording and reproducing data.
CM: Fine Clock Mark 3A, 3B are formed. Segment S0 at the beginning of the frame
After the fine clock marks 3A and 3B, address information indicating an address on the magneto-optical disk 100 is preformatted by the wobbles 4 to 9 when the magneto-optical disk 100 is manufactured.

Wobbles 4 and 5, wobble 6 and wobble 7, and wobble 8 and wobble 9 are formed on opposite walls of groove 1 and record the same address information. Such a recording method of the address information is called a one-sided staggered method, and by adopting the one-sided staggered method, a tilt or the like occurs in the magneto-optical disk 100,
Even when the laser beam deviates from the center of the groove 1 or the land 2, the address information can be accurately detected.

The area where the address information is recorded and the area where the fine clock marks 3A and 3B are formed are not used as areas for recording user data. The segment Sn is composed of fine clock marks 3A and 3B and user data n-1.

Referring to FIG. 3, each of bands B0 to B13 is composed of m frames F0 to Fm-1. The number of frames differs for each band B0 to B13. One frame is composed of 39 segments S0 to S38 as described above. Signals are recorded and / or reproduced on the magneto-optical disk 100 according to the data format shown in FIG.

Referring to FIG. 4, a detailed configuration of the segment will be described. Each segment S constituting the frame
Of the segments 0, S1, S2,..., S38, the segment S0 is an address segment preformatted on the magneto-optical disk 100, and the segments S1 to S38 are data segments secured as user data recording areas. . Segment S0 is 12DCB
The segment S1 is composed of a fine clock mark area FCM and an address of 520 DCB.
B includes a fine clock mark area FCM, 4DCB prewrite, 512DCB data, and 4DCB postwrite.

The prewrite indicates the writing of data, and is composed of, for example, a predetermined pattern "0011", and the postwrite indicates the end of data, and is composed of, for example, a predetermined pattern "1100". You.

In the user data area of the segment S1, there is provided a header which is a fixed pattern for performing data position confirmation at the time of reproduction, position compensation of a reproduction clock, laser power adjustment, and the like. The fixed pattern to be recorded in the header is a pattern in which a DC component is suppressed. For example, a pattern in which a predetermined number of 2T domains are formed at intervals of 2T and a pattern in which a predetermined number of 8T domains are formed at intervals of 8T are recorded. You.

The phase compensation is performed by adjusting the sampling timing of the analog signal obtained by reproducing the 2T domain so as to match the phase of the reproduced clock obtained by delaying the phase of the reference clock used for signal recording. To reproduce the 2T domain and the 8T domain, and adjust the laser power so that the ratio of the 2T domain reproduced signal intensity to the 8T domain reproduced signal intensity becomes 50% or more. Also, by reproducing the 8T domain and confirming whether the position of the digital signal obtained by binarizing the reproduced signal coincides with the position of the digital signal of the 8T domain predicted in advance, the position of the signal during reproduction can be confirmed. Do. Furthermore, each pattern of pre-write, post-write, and header is recorded continuously with user data when recording the user data.

Each of the segments S2 to S38 includes a 12DCB fine clock mark area FCM, 4DCB prewrite, 512DCB data, and 4DCB postwrite.

Referring to FIG. 5, the arrangement of the management information data and the main data on the magneto-optical disk 100 will be described. FIG. 5 shows a case where five files including management information data and main body data are recorded on the magneto-optical disk 100. The management information data 21 of the file 1, the management information data 22 of the file 2, and the management information data 23 of the file 3 are arranged in the area 20A. The body data 31 of the file 1, the body data 32 of the file 2, and the body data 33 of the file 3 are arranged in the area 30A. Management information data 24 of file 4 and file 5
Is stored in the area 40A. The body data of file 4 and the body data of file 5 are arranged in area 50A. As described above, the management information data and the main body data are discretely arranged on the magneto-optical disk 100.

The management information data and the main data are recorded on the magneto-optical disk 100 in units of ECC blocks in which 16 frames are collected. Therefore,
Management information data 21 to 23 or management information data 24,
25 may be included in one ECC block.

Referring to FIG. 6, an optical disk device 200 according to the present invention includes an optical pickup 110, an address detection circuit 120, an equalizer 130, and a decoder 140.
, An interface 150, and a buffer memory 160
And a CPU 170. In FIG. 6,
Only a reproducing system that reproduces a signal from the magneto-optical disk 100 and outputs reproduced data is shown. Therefore, an encoder and a magnetic head necessary for recording a signal on the magneto-optical disk 100 are omitted.

The optical pickup 110 irradiates the magneto-optical disk 100 with laser light and detects the reflected light. The address detection circuit 120 detects an address of each data on the magneto-optical disk 100 based on the radial push-pull signal detected by the optical pickup 110 from the magneto-optical disk 100, and stores the detected address in the CPU 170.
Output to

The equalizer 130 includes the optical pickup 11
The PR (1, 1) waveform equalization is performed on the reproduction signal detected from the magneto-optical disk 100 by 0 and converted into a digital signal. The decoder 140 is connected to the equalizer 13
The reproduced signal input from 0 is decoded to generate reproduced data. Also, under the control of the CPU 170, the decoder 140 buffers the decoded reproduction data in the buffer memory 160 by a method described later, reads the reproduction data from the buffer memory 160, and transmits the read reproduction data via the interface 150. To the host 180.

The interface 150 includes a decoder 140
Output playback data from the host 180 to the host 180,
It outputs various requests from the host to the CPU 170. C
The PU 170 searches the buffer memory 160 in response to a read data read request from the host 180 input via the interface 150. Also, the CPU 170
Controls the decoder 140 to perform prefetch buffering when it determines that the playback data requested from the host 180 is sequential playback data by a method described later. Further, when the CPU 170 determines that the reproduction data requested by the host 180 is the reproduction data to be used repeatedly by a method described later,
The decoder 140 controls the decoder 140 to decode the requested reproduction data and buffer the data in the buffer memory 160. In addition, the CPU 170 performs various operations as described later.

The host 180 requests the optical disk device 200 to read the reproduced data, and receives the reproduced data from the optical disk device 200.

Referring to FIG. 7, address signal AD and fine clock mark signal F from magneto-optical disk 100 are provided.
The detection of the CM and the magneto-optical signal RF will be described.
The area 10 and the area 30 constitute a preformat area that is preformatted when the magneto-optical disk 100 is manufactured. In the area 10, wobbles 4 to 7 and fine clock marks 3A and 3B are formed. The area 30
Are formed with fine clock marks 3A and 3B.
The area 20 constitutes a user data area, in which user data is recorded.

The photodetector 1020 in the optical pickup 110 for irradiating the magneto-optical disk 100 with laser light and detecting its reflected light has six detection areas 1020A and 1022.
0B, 1020C, 1020D, 1020E, 1020
F. The area A1020A and the area B1020B, and the area C1020C and the area D1020D are arranged in the tangential direction DR2 of the magneto-optical disk 100,
Area A1020A, Area D1020D, Area B1020
B and the area C1020C, and the area E1020E and the area F1020F are in the radial direction D of the magneto-optical disk 100.
It is located at R1.

The areas A1020A, B1020B, C1020C, and D1020D detect the reflected light of the laser beam LB applied to the magneto-optical disk 100 in the A, B, C, and D areas, respectively. . Further, a region E1020E and a region F102
0F transmits the laser light reflected by the entire laser light LB in the A region, the B region, the C region, and the D region in two directions having different polarization planes by the Wollaston prism (not shown) of the optical pickup 110. The diffracted laser light is detected.

The reproduction signal RF of the magneto-optical signal recorded in the area 20 which is the user data area has the laser light intensity [E] detected in the area E1020E of the photodetector 1020 and the laser light intensity detected in the area F1020F. It is detected by calculating the difference from [F]. That is, the circuit 4
The subtractor 400 of 0 calculates the difference between the laser light intensity [E] detected in the region E1020E and the laser light intensity [F] detected in the region F1020F, and obtains a reproduction signal RF =
[E]-[F] is output.

Area 10 constituting preformat area
The reproduction signal of the address information recorded by the wobbles 4 to 7 is detected by the radial push-pull method,
From the sum of the laser light intensity [A] detected in the region A1020A and the laser light intensity [B] detected in the region B1020B, the laser light intensity [C] detected in the region C1020C
And the sum of the laser beam intensity [D] detected in the area D1020D is detected. That is, the address signal AD is supplied to the adders 500 and 50 constituting the circuit 50.
It is detected by 1 and the subtractor 502. Adder 500
Is the laser beam intensity [A] detected in the area A1020A.
And [A + B] obtained by adding the laser beam intensity [B] detected in the area B1020B. The adder 501 outputs [C + D] obtained by adding the laser light intensity [C] detected in the region C1020C and the laser light intensity [D] detected in the region D1020D. Then, the subtractor 502
The output [C + D] of the adder 501 is subtracted from the output [A + B] of the adder 500 to obtain an address signal AD = [A + B] −
[C + D] is output.

The fine clock marks 3A and 3B in the area 30 constituting the preformat area are detected by a tangential push-pull method, and the area A10 is detected.
Laser light intensity [A] detected at 20A and area D102
From the sum with the laser light intensity [D] detected at 0D, the area B
Laser light intensity [B] detected at 1020B and area C1
It is detected as a value obtained by subtracting the sum with the laser light intensity [C] detected at 020C. That is, the fine clock marks 3A and 3B are added to the adder 50 constituting the circuit 50.
3, 504 and a subtractor 505. The adder 503 outputs [A + D] obtained by adding the laser light intensity [A] detected in the area A1020A and the laser light intensity [D] detected in the area D1020D. Adder 50
4 outputs [B + C] obtained by adding the laser beam intensity [B] detected in the region B1020B and the laser beam intensity [C] detected in the region C1020C. Then, the subtractor 505 subtracts the output [B + C] of the adder 504 from the output [A + D] of the adder 503, and outputs a fine clock mark signal FCM = [A + D]-[B + C].

The magneto-optical signal RF detected by the above-described method is output to the equalizer 130, and the address signal A
D is output to the address detection circuit 120. The address detection circuit 120 detects an address based on the address signal AD. Note that the fine clock mark signal FCM
Is output to a PLL circuit (not shown). And P
The LL circuit generates a clock as a reference when recording and / or reproducing signals on the magneto-optical disk 100 based on the fine clock mark signal FCM.

Referring to FIG. 8, the configuration of buffer memory 160 of optical disk device 200 shown in FIG. 6 will be described. The buffer memory 160 includes a ring buffer 161 and cell buffers 162 to 166. The ring buffer 161 is a buffer that stores and outputs reproduction data in a ring shape. That is, the ring buffer 161
Is the area 1 from address m to address n (n> m)
When the reproduction data is further stored in the state where the reproduction data is stored in the area 610, the area 1611 and the area 1612 from the address n + 1 to the address n + k are stored.
To store the playback data. Also, the ring buffer 161
When outputting the stored reproduction data, the area 1610
The reproduction data stored in the area 16 is output.
The playback data stored in 11, 1612 is output. As described above, the ring buffer 161 sequentially stores or outputs the reproduction data in a certain direction indicated by the arrow 167.

The cell buffers 162 to 166 store or output reproduced data by a usual method. The ring buffer 161 has a capacity to store reproduction data for 100 ECC blocks, and the cell buffers 162 to 16.
Each of 6 has a capacity to store reproduction data for 4 ECC blocks.

In the present invention, the sequential reproduction data is preferentially stored in the ring buffer 161 and the repeatedly used reproduction data is stored in the cell buffers 162 to 166.
Is stored preferentially. As the sequential reproduction data, for example, the reproduction data of the body data of each file described above is assumed, and as the reproduction data to be repeatedly used, for example, the reproduction data of the management information data described above is assumed. Therefore, in the present invention, the reproduction data of the main data reproduced from the magneto-optical disk 100 is preferentially stored in the ring buffer 161, and the reproduced data of the management information data reproduced from the magneto-optical disk 100 is stored in the cell buffers 162 to 166. Store preferentially. However, when the data size of the management information data is large and cannot be stored in the cell buffers 162 to 166,
The reproduction data is stored in the ring buffer 161.

Referring to FIG. 9, a description will be given of the processing operation of the drive when there is a read request for the reproduction data from host 180. When the power of the optical disk device 200 shown in FIG. 6 is turned on, the CPU 170 initializes a buffering management variable (step S10). That is, CP
U170 is a ring buffer last data buffer address variable that stores a buffering address value of the last data buffered in the ring buffer 161;
In addition, the last address value of the ring buffer 161 is set to a ring buffer last transfer data buffer address variable that stores an address value buffering the last data transferred from the ring buffer 161. Next, C
The PU 170 stores the LBA (Logical BL) of the first data buffered in the ring buffer 161.
The maximum LBA value of the user data area specified in the standard of the magneto-optical disk 100 is set in the ring buffer head data LBA variable storing the ACK Address value and the ring buffer final data LBA variable storing the LBA value of the final data. Set any large numerical value. The LBA value is the value of the user data magneto-optical disk 100.
The above address value. Next, the CPU 170 outputs a cell buffer head data LBA variable for storing the LBA value of the head data buffered in each of the cell buffers 162 to 166, and a cell buffer end data LBA variable for storing the LBA value of the end data. , The same value as the value set in the ring buffer head data LBA variable is set. Then, the CPU 170 controls the cell buffer 162
When the reproduction data is buffered in .about.166, "0" is set to the next cell buffer number variable for designating each of the cell buffers 162 to 166. Furthermore, CPU
Reference numeral 170 denotes a pre-read buffering last LBA variable that stores the address value of the last data to be buffered at the start of pre-read buffering, and stores the magneto-optical disk 1
Maximum LB of the user data area specified in the standard of 00
An arbitrary numerical value larger than the A value is set.

After the completion of the initialization, the CPU 170 sends a read request for read data from the host 180 to the interface 1.
When the information is received via the terminal 50 (step S20), a buffer search process is performed (step S30). In this case, CP
U170 receives a read request including the address value and the data length of the head data from host 180. Therefore, based on the received head data address value, whether the requested reproduction data is buffered in buffer memory 160 or not. Search for no. The details of the buffer search will be described later.

When the buffer search is completed, a data transfer process is performed (step S40). That is, CP
The U 170 controls the decoder 140 to read the reproduction data stored in the buffer memory 160 and transfer it to the host 180. When the data transfer process ends, the CPU 170 returns to step S20 and returns to host 1
Wait for a read request from 80.

Referring to FIG. 10, details of the buffer search process (step S30) of FIG. 9 will be described. CP
U 170 searches the ring buffer 161 of the buffer memory 160 based on the address value of the first data included in the read request of the reproduced data, and determines whether the reproduced data requested by the host 180 is buffered in the ring buffer 161. Is determined (step S301).
In this case, the CPU 170 refers to the ring buffer head data LBA variable and the ring buffer final data LBA variable, and includes the address value of the reproduction data requested by the host 180 within the range of the address values stored in these two variables. The ring buffer 161 is searched according to whether or not it is performed. The requested reproduction data is stored in the ring buffer 16.
When it is determined that the data is stored in No. 1, the operation of the buffer search process ends, and the process shifts to the data transfer process (step S40) shown in FIG.

When it is determined in step S301 that the requested reproduction data is not buffered in the ring buffer 161, the CPU 170 determines whether prefetch buffering is being executed (step S3).
02). In step S302, the CPU 170
When it is determined that prefetch buffering is being executed,
It is determined whether or not the reproduction data requested by the host 180 is included in the buffering target range in the prefetch buffering (step S303). Step S3
03, when it is determined that the reproduction data requested by the host 180 is included in the target range of the prefetch buffering, the CPU 170 waits for the reproduction data requested by the host 180 to be buffered (step S304). When the requested reproduction data is buffered, the buffer search process is terminated, and the process proceeds to the data transfer process (step S40) shown in FIG. 9 to control the decoder 140 to transfer the reproduction data to the host 180. I do.

The operations in steps S302 to S304 are requested when the read-ahead buffering is performed when it is determined that the reproduction data requested by the host 180 is not buffered in the ring buffer 161. Since there is a possibility that the reproduction data is buffered in the ring buffer 161, it is decided to wait for it.

If it is determined in step S302 that the prefetch buffering has not been performed, or if the reproduction data requested by the host 180 is not within the target range of the prefetch buffering in step S303, the process proceeds to step S305. I do. Step S30
In step 5, the CPU 170 sets n = 0, and the reproduction data requested by the host 180 is stored in the cell buffer 162.
(Step S30).
6). Note that n = 0 indicates the cell buffer 162, and n =
1 refers to the cell buffer 163, n = 2 refers to the cell buffer 164, n = 3 refers to the cell buffer 165, n
= 4 indicates the cell buffer 166. In this case, CPU1
70 searches the cell buffer 162 by checking whether or not the range of the address value stored in the cell buffer head data LBA variable and the cell buffer end data LBA variable includes the address value of the requested reproduction data. Do. When it is determined in step S306 that the requested reproduction data is stored in the cell buffer 162, the buffer search process ends, and the flow shifts to a data transfer process (step S40) shown in FIG.

When it is determined in step S306 that the requested reproduction data is not stored in the cell buffer 162, the CPU 170 sets n = n + 1 (step S307), and determines whether n is 4 or less. (Step S308). In step S308, n
Is determined to be 4 or less, Steps S306 to S306
S308 is repeated. In this case, since n = 1 is set, in step S306, the CPU 170
Retrieves whether or not the reproduction data requested by the host 180 is stored in the cell buffer 163. n is 4
By repeating steps S306 to S308 until it becomes larger than the above, all the searches in cell buffers 162 to 166 are performed. In step S304,
If it is determined that n is greater than 4, the cell buffer 16
No reproduction data requested by the host 180 is stored in any of the data items 2 to 166. In that case,
The process moves to step S350, and a buffering process described later is performed. Then, the operation of the buffer search process (step S30) ends.

Referring to FIG. 11, the buffering process (step S350) shown in FIG. 10 will be described in detail. When the buffering process is started, the CPU 170
Determines whether the prefetch buffering is being executed (step S351). If the prefetch buffering is being executed, the CPU 170 controls the decoder 140 to stop the prefetch buffering (step S35).
2). In this case, the reason why the prefetch buffering is stopped is that the prefetch buffering being executed needs to be stopped because the buffering process is to newly buffer the reproduction data.

When it is determined in step S351 that prefetch buffering has not been performed, or after step S352, CPU 170
It is determined whether or not the address value of the reproduction data requested from the above is an address value continuous with the address value of the reproduction data lastly transferred among the reproduction data transferred to the host 180 last time (step S353). In step S353, when the address value of the reproduction data requested from the host 180 is continuous with the address value of the reproduction data last transferred to the host 180 last time, the CPU 170 reads the sequential reproduction data from the host 180. , And clears all buffered reproduction data in the ring buffer 161 (step S35).
4). Then, the CPU 170 controls the decoder 140 to perform read-ahead buffering of the reproduction data from the ECC block including the head data requested by the host 180 to the ring buffer 161.
The reproduction data is pre-read buffered in the ring buffer 161 (step S355). Here, “read ahead buffering” means that the reproduction data continuous with the reproduction data requested by the host 180 is decoded before being requested by the host 180, and is buffered in the ring buffer 161. In this case, more specifically, the CPU 170 calculates an address value obtained by adding a value obtained by converting the total capacity of the ring buffer 161 to the number of frames to the address value of the first data requested from the host 180, Set to. And the CPU 17
0 controls the decoder 140 to buffer the reproduction data from the head data requested by the host 180 to the address value stored in the prefetch buffering last LBA variable in the ring buffer 161. The decoder 140 pre-reads and buffers the reproduction data in the ring buffer 161 based on the control from the CPU 170.

As soon as the head data is buffered in the ring buffer 161, the CPU 170 stores the address value of the reproduced data that has started buffering in the ring buffer head data LBA variable.
The address value of the buffered final data is stored in the ring buffer final data LBA variable. Also, CP
U170 stores the address value on the ring buffer 161 storing the last data in the ring buffer last data buffer address variable. As described above, when it is determined that the sequential reproduction data is requested, the reproduction data requested by the host 180 is pre-read and buffered in the ring buffer 161, and the operation of the buffering process ends.

On the other hand, in step S353, when the address value of the reproduction data requested from host 180 is discontinuous with the address value of the reproduction data last transferred to host 180 last time, CPU 170 is used repeatedly. It determines that reading of the reproduction data has been requested from the host 180, decodes the requested reproduction data, and controls the decoder 140 to buffer the decoded reproduction data in the cell buffers 162 to 166 of the buffer memory 160. Since the reproduction of the signal from the magneto-optical disk 100 is performed in ECC block units,
U170 indicates that the number of ECC blocks including the reproduction data requested by the host 180 is equal to the cell buffers 162 to 166.
It is determined whether or not the size is smaller than or equal to (step S356).
Since each of the cell buffers 162 to 166 has a size of 4 ECC blocks as described above, the host 18
When the reproduction data requested from 0 is recorded over 5 ECC blocks, it is determined in step S356 that the required number of ECC blocks is larger than the size of the cell buffers 162 to 166. When the required number of ECC blocks is larger than the size of the cell buffers 162 to 166, in steps S354 and S355, the CPU 170 controls the decoder 140 to buffer the repeatedly used reproduction data in the ring buffer 161.

In step S356, the necessary ECC
When it is determined that the number of blocks is equal to or smaller than the size of the cell buffers 162 to 166, the CPU 170 clears the buffered reproduction data stored in the cell buffer corresponding to the next cell buffer number (step S3).
57). In this case, the cell buffer corresponding to the next cell buffer number is determined as follows. That is, when buffering is performed for the first time, the cell buffers 162 to 162 are used.
Since the reproduction data is not stored in any of the cells 166, the cell buffer corresponding to the next cell buffer number is n
= 0 is determined as the cell buffer 162. In the second and subsequent buffering processes, the cell buffer 16
Since the reproduction data has already been stored in any of 2 to 166, the cell buffer corresponding to the next cell buffer number is determined to be the cell buffer next to the cell buffer storing the reproduction data.

Thereafter, the CPU 170 controls the decoder 140 to buffer the cell buffer corresponding to the next cell buffer number from the head data of the reproduction data requested by the host 180.
Stores the reproduction data in the cell buffer corresponding to the next cell buffer number (step S358). In this case, C
More specifically, immediately after the buffering is started, the PU 170 immediately stores the address value of the first reproduced data in the cell buffer head data LBA variable of the buffered cell buffer immediately after the first reproduced data is buffered in the cell buffer. After that, the address value of the buffered final data is stored in the cell buffer final data LBA variable as needed.

When the buffering of the reproduction data in the cell buffer is completed, CPU 170 adds "1" to the next cell buffer number (step S359), and determines whether or not the next cell buffer number is 4 or less (step S359). S36
0). If it is determined in step S360 that the next cell buffer number is equal to or smaller than 4, it is determined that there is room for further buffering the reproduction data in the cell buffer 166, and the buffering process ends. On the other hand, step S
In 360, when the next cell buffer number is larger than 4, since the reproduction data is buffered in all of the cell buffers 162 to 166, the next cell buffer number is set to "0" (step S361), and the buffering is performed. The operation of the process ends.

As described above, the request from the host 180 depends on whether or not the address value of the reproduced data requested from the host 180 is continuous with the address value of the reproduced data last transferred to the host 180 last time. It is determined whether the playback data is sequential playback data or playback data that is used repeatedly. When sequential playback data is requested from the host 180, read-ahead buffering of the playback data is performed in the ring buffer 161 and the playback data repeatedly used is stored in the host 18.
0 when requested, cell buffers 162-16
In 6, the reproduction data is buffered.

Referring to FIG. 12, details of the data transfer process (step S40) shown in FIG. 9 will be described. When the data transfer process is started, the CPU 170
The reproduced data requested from the buffer memory 160
Ring buffer 161 or cell buffer 162-1
66, and controls the decoder 140 to transfer the read reproduction data to the host 180 via the interface 150. In this case, the CPU 170 determines in step S301 of FIG.
When the playback data is stored in the ring buffer 161 or after step S355 in FIG. 11, the decoder 140 is controlled to read the playback data from the ring buffer 161. In step S306 in FIG. 10, the cell buffers 162 to 166 are read.
When the playback data is stored in the
After 360 and 361, the decoder 140 is controlled so as to read the reproduction data from the cell buffers 162 to 166.

The decoder 140 reads the reproduced data from the ring buffer 161 or the cell buffers 162 to 166 according to the respective cases, and transmits the read reproduced data to the host 18 via the interface 150.
0 (step S401). And CPU1
70 stores the address value (LBA) of the last transfer last data transferred to the host 180 in the last transfer last data LBA variable (step S402). After that, CPU1
70 determines whether or not the reproduction data is to be transferred from the ring buffer 161 (step S403), and ends the data transfer process if the reproduction data is not to be transferred from the ring buffer 161.

When it is determined in step S403 that the transfer of the reproduction data from the ring buffer 161 is to be performed, the CPU 170 sets the address value (LBA) of the last transfer data stored in the last transfer last data LBA variable in step S402 to the ring. Buffer final transfer data L
It is stored in a BA variable (step S404). And C
The PU 170 determines whether or not the prefetch buffering is stopped (Step S405). When the prefetch buffering is being executed, the data transfer process ends. If it is determined in step S405 that the prefetch buffering is stopped, the CPU 170 determines whether the ring buffer final transfer data buffer address variable value matches the ring buffer final buffer address value (step S406). . In step S406, when it is determined that the ring buffer final transfer data buffer address variable value does not match the ring buffer final buffer address value, a free area exists in the ring buffer 161.

Referring to FIGS. 13 and 14, a case where a free area exists in ring buffer 161 will be described in detail. Referring to FIG. 13, when ring buffer final transfer data buffer address variable value Xi is smaller than ring buffer final buffer address value Xj, reproduced data is buffered in area 60 and areas 61 and 62 are read.
Is an empty area where the reproduction data has been transferred to the host 180. Therefore, in the case shown in FIG.
Buffering is newly performed in the order of the area 61 and the area 62.

Referring to FIG. 14, when ring buffer final transfer data buffer address variable value Xi is larger than ring buffer final buffer address value Xj, reproduced data is buffered in area 70 and area 71, and area 72 Is an empty area where the reproduction data has been transferred to the host 180. Therefore, in the case shown in FIG.
The reproduction data is newly buffered in the area 72.

In the case shown in FIGS. 13 and 14, it means that the ring buffer final transfer data buffer address variable value does not match the ring buffer final buffer address value. When it is determined that the buffer address variable value does not match the ring buffer final buffer address value, a free area exists in the ring buffer 161. Further, when it is determined in step S406 that the ring buffer final transfer data buffer address variable value matches the ring buffer final buffer address value, there is no free area in the ring buffer 161 as is clear from FIGS.

Referring again to FIG. 12, step S40
In step 6, when it is determined that the ring buffer final transfer data buffer address variable value matches the ring buffer final buffer address value, there is no free space in the ring buffer 161 and prefetch buffering cannot be performed. The process ends. on the other hand,
If it is determined in step S406 that the ring buffer final transfer data buffer address variable value does not match the ring buffer final buffer address value, the CP
U 170 determines that there is a free area in ring buffer 161, and controls decoder 140 to perform pre-read buffering of the reproduction data in free areas 61, 62, and 72. , 62, and 72, the read-ahead buffering of the reproduction data is performed (step S407).

In step S406, when it is determined that there is an empty area in the ring buffer 161, the prefetch buffering is performed in the ring buffer 1
Reproduced data having a continuous address value is stored in 61 and a part of the stored reproduced data is stored in the host 180.
This means that the host 180 is requesting sequential reading of read data.

Then, in step S407, prefetch buffering is performed, and the data transfer process ends.

Referring again to FIG. 6, optical disk device 200 responds to a read request for read data from host 180.
Will be described. When CPU 170 receives a read request for read data from host 180 via interface 150, CPU 170 executes the above-described buffer search process, data transfer process, and buffering process based on the address value of the read data included in the read request. I do. When performing prefetch buffering in these processes, the CPU 170 moves the optical pickup 110 to the position of the address value included in the read request by a servo mechanism (not shown). A signal recorded at a position specified by the address value of the requested reproduction data is detected from the magneto-optical disk 110, an address signal AD is output to the address detection circuit 120, and a reproduction signal is output to the equalizer 130. Address detection circuit 120 detects an address value based on address signal AD, and outputs the detected address value to CPU 170.

On the other hand, equalizer 130 performs PR (1, 1) waveform equalization on the input reproduced signal, and outputs the reproduced signal after waveform equalization to decoder 140. Decoder 14
0 decodes a reproduction signal and generates reproduction data.
Then, the CPU 170 uses the address value input from the address detection circuit 120 to pre-read buffered reproduction data having an address value continuous with the address value of the reproduction data requested by the host 180 into a free area of the ring buffer 161. Is performed, and the decoder 140 performs pre-read buffering of the reproduction data in the empty area. Also, the CPU 170
The decoder 140 is controlled so that the reproduction data requested by the host 180 is read from the ring buffer 161 and output to the host 180, and the decoder 140
0 is read from the ring buffer 161 and the read reproduction data is read from the interface 1
Output to the host 180 via 50.

In the above-described buffer search processing, data transfer processing, and buffering processing, the CPU 17
0, the decoder 140 decodes the playback data requested by the host 180 when it determines that the playback data to be used repeatedly is requested, and buffers the decoded playback data in the cell buffers 162 to 166. And the decoder 140 transfers the reproduced data requested by the host 180 to the cell buffers 162 to 166.
To buffer. In other words, when the repeatedly used reproduction data is requested from the host 180, the CPU 17
0 instructs the decoder 140 to decode the reproduction data and buffer the cell buffers 162 to 166 after receiving a request from the host 180. Therefore, the operation when the repeatedly used reproduction data is requested is performed by sequentially reproducing the reproduction data from the host 180.
This is different from the operation when requested from. When the sequential reproduction data is requested, the CPU 170 decodes the reproduction data continuous with the reproduction data requested from the host 180 before requesting the host 180, and buffers the decoded data in the ring buffer 161 so as to buffer the reproduction data. Is controlled.

As described above, the optical disk device 200
Determines whether the playback data is sequential playback data or repeatedly used playback data when requested to read the playback data from the host 180,
When the data is sequential reproduction data, the ring buffer 161 is pre-read buffered. When the reproduction data is used repeatedly, the cell buffers 162 to 162 are read.
6 is buffered.

In the above description, a case has been described in which a signal is reproduced from a magneto-optical disk and reproduced data is output to a host. However, the present invention is not limited to such a case.
The present invention is also applicable to signal reproduction from an optical disk such as a VD-RAM.

According to the embodiment of the present invention, the optical disk apparatus determines whether the playback data requested by the host is sequential playback data or repeatedly used playback data, and determines whether the playback data is sequential playback data. In the case of, read-ahead buffering is performed on the ring buffer, and when the reproduced data is used repeatedly, buffering is performed on the cell buffer. Therefore, buffering suitable for the type of reproduced data requested by the host can be performed.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[Brief description of the drawings]

FIG. 1 is a plan view conceptually showing a band structure of a magneto-optical disk.

FIG. 2 is a plan view showing a magneto-optical disk and its format.

FIG. 3 is a diagram for explaining the relationship between bands, frames, and segments.

FIG. 4 is a schematic diagram showing a format of a recording data string.

FIG. 5 is a conceptual diagram showing the arrangement of management information data and main body data on a magneto-optical disk.

FIG. 6 is a schematic block diagram of an optical disk device according to the present invention.

FIG. 7 is a diagram for explaining reproduction of data from a preformat area and a user data area.

FIG. 8 is a structural diagram of a buffer memory shown in FIG. 6;

FIG. 9 is a flowchart showing a processing operation of the optical disk device when a request to read reproduction data is issued from the host.

FIG. 10 is a flowchart showing details of the operation of the buffer search process shown in FIG. 9;

11 is a flowchart showing details of the operation of the buffering process shown in FIG.

FIG. 12 is a flowchart showing details of the operation of the data transfer process shown in FIG. 9;

FIG. 13 is a state diagram of a ring buffer in a buffering process.

FIG. 14 is another state diagram of the ring buffer in the buffering process.

[Explanation of symbols]

1 groove, 2 lands, 3A, 3B fine clock mark, 4 to 9 wobbles, 10, 30 preformat area, 20 user data area, 20A, 30
A, 40A, 50A, 60-62, 70-72, 102
0A, 1020B, 1020C, 1020D, 1020
E, 1020F, 1610-1612 area, 21-25
Management information data, 31 to 35 body data, 40, 5
0 circuit, 100 magneto-optical disk, 110 optical pickup, 120 address detection circuit, 130 equalizer, 140 decoder, 150 interface, 16
0 buffer memory, 161 ring buffer, 162
~ 166 cell buffer, 167 arrow, 170 CP
U, 180 host, 200 optical disk device, 40
0, 502, 505 Subtractor, 500, 501, 50
3,504 adder, 1020 photodetector.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 12/08 557 G06F 12/08 557 559 559D 12/12 505 12/12 505 H04N 5/85 H04N 5 / 85 Z

Claims (9)

[Claims] 1. An optical disk device for reproducing a signal from an optical disk in response to a read data read request from a host and outputting the reproduced data to the host, irradiating the optical disk with laser light, An optical pickup that detects the reflected light; a decoding unit that decodes a reproduction signal reproduced from the optical disk by the optical pickup to generate reproduction data; a storage unit that temporarily stores the reproduction data; Storage means for storing the reproduction data requested by the host from the storage means and outputting the read data to the host; and a control means. Is determined to have been requested by the host, the playback data following the requested playback data is determined. Controlling the storage means to perform prefetch buffering for prefetching and storing the readout data in the storage means, and when it is determined that the repeatedly used reproduction data is requested by the host, the requested reproduction data is stored in the storage means. An optical disk device, wherein the decoding means is controlled to generate the data, and the storage means is controlled to store the reproduction data generated by the decoding means in the storage means. 2. The control means searches the storage means in response to a reproduction data read request from the host, and the storage means does not store the reproduction data, and the output means outputs the host data. 2. The optical disc device according to claim 1, wherein when it is requested to read the reproduction data subsequent to the reproduction data output to the CPU, it is determined that the reading of the sequential reproduction data is requested. 3. The control means searches the storage means in response to a read data read request from the host, and the storage means does not store the reproduced data, and the output means outputs the host data. The optical disk device according to claim 1, wherein when it is requested to read out the reproduction data that is not continuous with the reproduction data output to the reproduction device, it is determined that the reading of the reproduction data used repeatedly is requested. 4. The control means according to claim 1, wherein the reproduction data requested by the host is reproduction data following the reproduction data output to the host by the output means, based on an address value of the reproduction data on the optical disk; 4. The optical disk device according to claim 2, wherein the optical disk device determines whether the data is non-continuous reproduction data. 5. The storage device according to claim 1, wherein the storage unit is a first storage unit configured to store sequential reproduction data.
Storage area, and a second storage area suitable for storing repeatedly used reproduction data.
2. The storage device according to claim 1, wherein the storage unit stores the sequential reproduction data in the first storage region, and stores the repeatedly used reproduction data in the second storage region. An optical disk device as described in the above. 6. The control means searches the storage means in response to a reproduction data read request from the host, and the reproduction data requested by the host is stored in the first storage area. 6. The optical disc device according to claim 5, wherein when the first storage area has a free area, the read of the sequential reproduction data is determined to be requested. 7. A reproduction data stored in said first storage area, wherein an address value indicating a position at which the last reproduction data is stored is set as a first storage address value, and is output to said host by said output means. When the second storage address value is an address value indicating the position where the last reproduction data is stored in the reproduced data, the control unit determines that the first storage address value is the second storage address value.
7. The optical disk device according to claim 6, wherein when the storage address value does not match the first storage area, it is determined that there is a free area in the first storage area. 8. The optical disk device according to claim 6, wherein said control means controls said storage means to store said reproduction data in said empty area by said prefetch buffering. 9. The control device according to claim 6, wherein the control unit performs a search in the order of the first storage area and the second storage area.
An optical disk device according to claim 1.