JPH08161868A - Reproducing device - Google Patents

Abstract

PURPOSE: To realize the high speed access even when an amt. of discrepancy between a data address and an absolute address is varied according to an area in a disk by making a comparison between a data address from an address detecting part and an absolute address from an absolute address detecting part by a control part and calculating their discrepant amt. as a correction amt. CONSTITUTION: Loading processing is performed when insertion of a CD-ROM 7 is confirmed by a control part 1. A servo circuit 10 is controlled by the control part 1 to move a pickup 2 to an inner circumference of the disk 7 for the purpose of reading a TOC. The circuit 10 is controlled by the control part 1 to servo-drive a spindle motor 3 for the purpose of focus tracking. The TOC is read in by the control part 1. Whether a data area is in existence or not is discriminated by the control part 1 from the TOC information, and if in existence, an absolute address range of the whole area is set in the TOC. In the reproducing device, the data address and the absolute address are compared with each other, and a target absolute address is offset with their discrepant amt. as the correction amt., and a reproducing head is moved to the corrected target absolute address, thus shortening the access time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing device, and more particularly to a reproducing device suitable for an optical disk device which requires high speed processing.

[0002]

2. Description of the Related Art On a CD-ROM disc, a header address for data and a subcode Q address indicating the absolute address of the disc are recorded as addresses.

In a conventional CD-ROM device, a CD-R
When reading data from the OM disk, the subcode Q address was first accessed to the target, and then the target header address was accessed.

The reason why the target header address is not accessed from the beginning must be compatible with CDDA audio data in which data is accessed only with the subcode Q address, and the header address is obtained after the reproduction signal is CD-decoded. This is because it takes time to detect it.

Therefore, in the conventional CD-ROM device, when there is a deviation between the header address and the subcode Q address,
The larger the shift amount, the longer it takes to access the target header address after the target subcode Q address is accessed.
There was a problem of increasing the total access time.

The amount of deviation between the header address and the subcode Q address is within ± 1 second, which is specified in the CD-ROM standard and the like.

A technique for solving this problem is Japanese Patent Publication No.
No. -60191 and Japanese Patent Laid-Open No. 3-1373.

As shown in FIG. 6, Japanese Patent Publication No. 5-601.
The CD-ROM device in Japanese Patent No. 91 is a CD-ROM
Pickup 2 that reproduces pit information on disc 21
2, a signal reproducing section 24 for generating an RF signal and a servo signal from the pit information from the pickup 22, and a signal processing circuit 25 for performing a CD decoding process on the RF signal from the signal reproducing section 24.

Further, a subcode Q detecting section 26 for detecting a subcode from the signal being CD-decoded from the signal processing circuit 25 and detecting subcode Q data which is the absolute address of the disc therein, and a signal processing circuit. CD-R that performs CD-ROM decoding processing on the signal output from
An OM signal processing circuit 28 and a header information detector 29 for detecting header information, which is an address dedicated to data, from a signal being decoded by a CD-ROM are provided.

Further, a pickup driving section 31 for driving the pickup 22 and a disk loading / unloading signal generating section 30 for outputting a disk loading / unloading signal when a CD-ROM disk is loaded.
The pickup drive unit 31 and the spindle motor 23 are controlled on the basis of the disc loading / unloading signal from the disc loading / unloading signal generation unit 30, the subcode Q address from the subcode Q detection unit 26, and the header address from the header information detection unit 29. And a control unit 27.

The signal read from the CD-ROM disc 21 via the pickup 22 is further passed through the signal reproducing unit 24 and the signal processing circuit 25 to the subcode Q detecting unit 2.
Sent to 6.

The subcode Q detection unit 26 extracts the subcode Q address from the output signal of the signal processing circuit 25 and notifies the control unit 27 of it.

If the subcode Q address is not the target value, the control section 27 drives the pickup driving section 31 to move the pickup 22.

When the subcode Q address reaches the target value, the control unit 27 causes the CD-ROM signal processing circuit 2 to operate.
8 and the header information detection unit 29 to read the header address, and wait until the header address at the target position can be read.

This waiting time becomes a deviation amount 33 as shown in FIG. Here, Qn indicates a subcode Q address, Hn indicates a header address, and the same n indicates that they correspond to each other.

In Japanese Patent Publication No. 5-60191, as shown in the flowchart of FIG. 8, when a CD-ROM disc is loaded, the control unit 27 sends a disc loading / unloading signal output from the disc loading / unloading signal generating unit 30. A shift amount 33 is detected as timing, and a difference between the shift amount 33 and a certain set amount 34 is calculated as an offset amount 35 (steps S101 to S103 in FIG. 8), which corresponds to the offset amount 35 at the time of subsequent data access. The sub-code Q address is shifted by the amount corresponding to the change in the target sub-code Q address (step S104 in FIG. 8).
-Step S107).

Here, steps S101 to S103 in FIG. 8 are the operations when the control section 27 detects the signal from the disk loading / unloading signal generating section 30, and steps S104 to S107 are the operations at the time of access. There is.

A case where the amount of deviation differs depending on the area within the disc is disclosed in Japanese Patent Laid-Open No. 3-1373.

As shown in FIG. 9, at the time of access, it is checked whether or not there is a deviation for each access (step S207 in FIG. 9). If there is a deviation, the correction value Ac is updated to set the target address. Redo (step S20 in FIG. 9)
8).

[0020]

However, in the above-mentioned conventional example, in Japanese Patent Publication No. 5-60191, since the processing is performed by regarding the displacement amount in the disk as constant, the displacement amount in the disk is different. If there is an area, there is a disadvantage that the effect of shortening the access time cannot be obtained because the deviation amount cannot be corrected until the disc is replaced, and if the deviation amount of the header address and the subcode Q address is wrongly detected. However, there is an inconvenience that the effect of shortening the access time cannot be expected.

Further, in Japanese Patent Laid-Open No. 3-1373, in order to correct the deviation amount for each access, in the case of access between areas having different deviation amounts, step S2 in FIG.
The operation from 03 to step S208 is repeated, and the effect of shortening the access time is lost.

[0022]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reproducing apparatus capable of improving the disadvantages of the conventional example and realizing a high-speed access especially when the deviation amount between the data address and the absolute address differs depending on the area in the disc. Especially.

[0023]

Therefore, in the present invention, a reproducing section for reading a reproduced signal from a recording medium, a data address detecting section for detecting a data address from the reproduced signal from the reproducing section, and a reproducing section are provided. Of the absolute address of the medium from the reproduction signal of the medium, and the correction amount is calculated from the difference between the data address from the data address detection unit and the absolute address from the absolute address detection unit. A control unit for offset correction to the target absolute address is provided, and so on. This aims to achieve the above-mentioned object.

[0024]

The control unit compares the data address from the address detection unit with the absolute address from the absolute address detection unit,
The deviation amount is used as a correction value to offset the target absolute address, and the reproducing head is moved to the corrected target absolute address.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

The embodiment shown in FIG. 1 shows the case where the present invention is applied to a CD-ROM device.
A pickup 2 that reproduces pit information on the disc from the OM disc 7, a signal reproducing unit (reproduction unit) 4 that generates an RF signal or a servo signal from the pit information from the pickup 2, and an RF signal from the signal reproducing unit 4. A signal processing circuit 5 for performing CD decoding processing, and C from the signal processing circuit 5
A subcode Q detection unit (absolute address detection unit) 6 that detects a subcode from the D decode signal and extracts subcode Q data that is the absolute address of the disc, and a CD-ROM for the CD decode signal from the signal processing circuit 5. CD-ROM signal processing circuit 8 for decoding and CD-ROM
A header information detection unit (data address detection unit) 9 that extracts a header address that is a dedicated address for data from the CD-ROM decode signal from the signal processing circuit 8, and a servo circuit unit 10 that drives the pickup 2 and the spindle motor 3. , A correction value of the target absolute address is calculated based on the subcode Q address from the subcode Q detection unit 6 and the header address from the header information detection unit 9, and the servo circuit 10 is calculated.
And a control unit (control unit) 1 for controlling the.

Next, the control unit 1 in this embodiment
The operation will be described with reference to the flowcharts of FIGS.

1. Correction amount calculation process:

(1). The control unit 1 is a CD-RO
When it is confirmed that the M disc 7 is inserted, a loading process is performed (step S301 in FIG. 2).

(2). The control unit 1 controls the servo circuit unit 10 to read the TOC and moves the pickup 2 to the inner circumference of the CD-ROM disc 7 (step S302 in FIG. 2).

(3). The control unit 1 controls the servo circuit unit 10 to servo-drive the spindle motor 3 for focus / tracking (step S in FIG. 2).
303).

(4). The control unit 1 reads the TOC (step S304 in FIG. 2).

The operation up to this point is the operation of a normal CD-ROM device.

(5). The control unit 1 determines from the TOC information whether or not there is a data area (see FIG. 2).
Step S305).

If there is no data area, it is determined that the disc is a CDDA audio disc, and the process ends.

On the other hand, if a data area exists, the absolute address (subcode Q address) range of the entire area is set to DT.
It is set to 0 (step S306 in FIG. 2).

(6). The control unit 1 starts playback access to the designated data area (step S307 in FIG. 2).

(7). The control unit 1 reads the subcode Q address from the subcode Q detection unit 6 and the header address from the header information detection unit 9, calculates the difference, and sets it as the correction value A0 (step S308 in FIG. 2).

The control unit 1 performs the following processing in order to accurately determine the difference An.

(7-1). The correction value is An
= Bn = 0 is set (step S341 in FIG. 4).

(7-2). Detection of subcode Q address by subcode Q detection unit 6 (step S342 in FIG. 4)
And the header information detection unit 9 detects the header address (see FIG. 4).
Step S343) is simultaneously performed to set the address difference to An (step S344 in FIG. 4).

(7-3). The set value of An and the set value of Bn are compared (step S345 in FIG. 4). If they are equal, the process is ended. If they are not equal, the value of An is set to Bn (step S346 in FIG. 4), and the above process is performed again. (7-2)
Return to.

In this example, the condition for determining An is that An is equal to two continuous values, but other continuous values may be set.

Further, if An is not determined even after reproducing for a while, it is desirable to finish with An set to zero.

Up to this point (step S308 in FIG. 2), processing is performed on a normal CD-ROM disc.

However, when the disc is a CD-WO disc (CD-ROM write-once disc), a plurality of areas having different recording times and recording devices exist in the same disc, so that the subcode Q address and the header address are different. The amount of deviation may differ depending on the area.

Next, additional processing in the control unit 1 when the disc is a CD-WO disc will be described with reference to FIG.

(8). The control unit 1 terminates the process if the start address value of the next writable area is not recorded in the TOC area on the innermost side of the disc, and if the start address value is recorded, the recordable CD-WO It is determined that the disc is a disc (step S309 in FIG. 3), and if additional recording has already been performed, the area that is the second TOC is accessed (step S310 in FIG. 3).

(9). The control unit 1 uses this TOC
It is determined whether or not the TOC exists in the area (step S311 in FIG. 3). If the TOC does not exist, the process ends. If the TOC exists, the absolute address of the entire additional write program area (subcode Q Address) range DTn
(Step S312 in FIG. 3).

(10). Next, the arbitrary data area in the additional recording area is accessed (step S313 in FIG. 3).

(11). The control unit 1 operates in the data area in the same manner as in the above processing (7) by the subcode Q detection unit
The subcode Q address from the header information and the header address from the header information detector 9 are continuously compared to calculate the difference, and the difference is set as the correction value An (step S314 in FIG. 3).

(12). The control unit 1 determines whether or not the start address value of the next writable area is recorded in the TOC area in the processing (9) (step S315 in FIG. 3), and if it is recorded, the above processing ( 8)
Then, the process is repeated, but if not recorded, the process ends.

2. Access operation to the data area after the correction amount calculation process:

(1). When the target subcode Q address is set, the control unit 1 determines which area of DTn the address is in (step S321 in FIG. 5), and sets the correction value An corresponding to the area to the current target subcode Q. In addition to the address, a new target subcode Q address is set (step S322 in FIG. 5).

(2). The control unit 1 accesses the target subcode Q address determined by controlling the servo circuit unit 10 (step S323 in FIG. 5), and subsequently detects the head header address of the data to be read (step S324 in FIG. 5). , Data read processing is performed (step S325 in FIG. 5).

As described above, the reproducing apparatus according to the present embodiment compares the data address with the absolute address and offsets the deviation amount to the target absolute address as a correction value. Then, by moving the reproducing head to the corrected target absolute address, it is possible to shorten the access time of the disk in which the data address and the absolute address are different from each other.

Further, when detecting the deviation amount between the data address and the absolute address, the data address and the absolute address are reproduced a plurality of times in the area where the data address exists, and the continuous comparison is performed to improve the accuracy of the deviation amount detection. Can be raised.

When the medium is a medium in which additional recording is performed a plurality of times, the deviation amount of the data address and the absolute address is calculated for each additional recording area, and each correction value is set when accessing each area. By offsetting access to the target absolute address, it is possible to shorten the access time between areas having different amounts of deviation.

Although the present embodiment describes the case where the present invention is applied to a CD-ROM device, the present invention is not limited to this and is also used when reproducing data from a disk-shaped recording medium. It is possible.

[0060]

Since the present invention is constructed and functions as described above, according to this, the control unit compares the data address from the address detection unit with the absolute address from the absolute address detection unit and determines the deviation amount. Since it is calculated as a correction value,
The deviation amount between the data address and the absolute address can be detected with high accuracy, and therefore, a high-speed playback device which has not been available in the past can realize high-speed access even when the deviation amount between the data address and the absolute address differs depending on the area in the disc. Can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a correction amount calculation process with the configuration shown in FIG.

FIG. 3 is a flowchart showing an example of a correction amount calculation process for a write-once disc having the configuration shown in FIG.

FIG. 4 is a flowchart showing details of the correction amount calculation processing shown in FIG.

5 is a flowchart showing an example of access processing to a data area according to the configuration shown in FIG.

FIG. 6 is a block diagram showing a configuration of a conventional example.

FIG. 7 is an explanatory diagram showing a shift amount in the conventional example shown in FIG.

8 is a flowchart showing the operation of the conventional example of FIG.

FIG. 9 is a flowchart for explaining the operation of the second conventional example.

[Explanation of symbols]

 1 Control Section (Control Section) 2 Pickup 3 Spindle Motor 4 Signal Reproducing Section (Reproducing Section) 5 Signal Processing Circuit Section 6 Subcode Q Detection Section (Absolute Address Detection Section) 7 CD-ROM Disc 8 CD-ROM Signal Processing Circuit 9 Header information detection unit (data address detection unit) 10 Servo circuit unit

Claims (3)

[Claims] 1. A reproducing section for reading a reproduced signal from a recording medium, a data address detecting section for detecting a data address from the reproduced signal from the reproducing section, and an absolute address of the medium based on the reproduced signal from the reproducing section. A correction amount is calculated from the absolute address detection unit to be detected and the difference between the data address from the data address detection unit and the absolute address from the absolute address detection unit, and at the time of access, offset correction is performed to the target absolute address based on the correction amount. A reproducing apparatus comprising a control unit. 2. The control unit comprises means for determining a correction value of a target absolute address by comparing a data address from the address detection unit and an absolute address from the absolute address detection unit a plurality of times. The reproducing apparatus according to claim 1, wherein the reproducing apparatus is characterized in that: 3. The control unit, when the recording medium is a medium in which data is additionally written a plurality of times, sets a data address from the address detection unit and an absolute address from the absolute address detection unit for each additional write area. The reproducing apparatus according to claim 1, further comprising means for calculating a correction value from the difference between