JPH05298834A - Defect inspecting method for magneto-optical disk - Google Patents

Abstract

PURPOSE:To inhibit the defect detection of partial ROM and an ID section in the defect inspection of partial ROM magneto-optical disk and to inspect the data section of the sector in which partial ROM are not set. CONSTITUTION:An optical head 2 reads the tracks which are beforehand pit recorded in the SFP section of a specific track of a disk 1 and the address numbers of the sector and are stored in a RAM 45. As the disk rotates, the tracks and the sector numbers are sequentially read and when the address numbers coincide with the numbers stored in the RAM, inhibit the defect detection against the sector of the track and a defect inspection is executed for the data section of the sector which does not coincide with the address number. Therefore, the disturbance of reflected light of partial ROM against the defect detection is eliminated and a highly reliable inspection is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect inspection method for a magneto-optical disk, and particularly to a partial ROM type magneto-optical disk.

[0002]

2. Description of the Related Art Magneto-optical disks are being developed as high density recording media in which information data can be rewritten.
2, a method of recording data on the magneto-optical disk,
And the inspection method is explained. In FIG. 2 (a), 1 is a magneto-optical disk and 2 is an optical head. The disc 1 a number of tracks T _R is set for the focus and tracking the optical head 2 servo, divided into a plurality of sectors S ₀ to S _m in the circumferential direction of each track T _R is the index (IND) starting To be done. (b) is a development view of each track, in which each sector is provided with an ID section and a DATA section,
As shown in (c), identification information for the sector number and the like is recorded in advance in pits (circle) in the ID part, and
Data is magnetically recorded in the A section by the optical head 2 or the like (×
Will be added or updated. In the fabrication of the magneto-optical disk, first track on the master by etching T _R
Then, the master is nickel-plated to make a stamper, and a large number of disks are duplicated. Data can be rewritten on the magneto-optical disk, but since the ID section does not need to be rewritten, it is pre-formatted together with the track groove at the stage of the master and transferred to each disk through the stamper.

When the magneto-optical disk 1 has a defect, the recording performance is deteriorated, and therefore a defect inspection is performed. The defect inspection is first strictly performed at the stage of the master and the stamper, and further, for each disc, an optical inspection of the DATA portion and an error test by subsequent writing / reading of data are performed. In the optical inspection, defects such as irregularities existing in the DATA portion are optically detected. In this case, as shown in FIG. 2 (d), together with the reflected pulse p _K due to a defect in the DATA portion, reflected pulse p _ID by the pre Homat the ID pits is detected in the ID portion, it is impossible to distinguish between the two. Therefore, ID in the detection circuit
A method of inhibiting the detection of the reflection pulse p _ID of the pit and detecting only the defect is adopted.

By the way, the standard size of the magneto-optical disk at the beginning is 5.25 inches, and the above optical inspection has been performed for this. However, recently, the small size 3.
The 5-inch disc has been standardized by ISO, and the recording format has been partially changed accordingly. That is, in the conventional 5.25 inch, the DATA section is a so-called user area in which the user arbitrarily writes or updates the data, but according to the ISO standard for 3.5 inch, the DATA section is not used for a part of the user area. It is allowed to record arbitrary data in advance by pit recording. This will be described in some detail and concretely with reference to FIG. 3 (a) shows the sector S _r to S _t consecutive of a portion of the appropriate track, conventionally ID pits in the ID portion of each sector (○ mark) is recorded. On the other hand, for example, in each DATA portion of the sectors S _{r to} S (s-1), arbitrary data is pit-recorded in advance at the stage of the master and is transferred to each disc, so that this portion of the data is Cannot be used for recording. In contrast, the DATA portion of the sector S _s to S _t can be used as a recording area. The above arbitrary data is naturally not rewritable and is used as read-only (ROM) data. However, since it is partially set on the track, not on the entire surface of the disc, it is considered as a partial (partial) ROM. to be called. The track number of the partial ROM and the sector number of each sector are prepit-recorded as an address number on the SFP (standard format) provided on a specific track on the outer periphery of the disc, and the set position is displayed. ing. As described above, the partial ROM is set.
The 5-inch disc is called a partial ROM type magneto-optical disc, a partial ROM disc, or the like.

[0005]

[Problems to be Solved by the Invention] The above-mentioned partial RO
When the above-mentioned conventional optical inspection is performed on the M-type magneto-optical disk, as shown in FIG. 3 (b), the reflection from the pit of the partial ROM is the same as the reflection pulse p _ID for the ID pit. Since the pulse p _p is detected, the reflection pulse p _K for the defect is the same as in the case of the ID section described above.
Indistinguishable. On the other hand, it is necessary to inhibit the detection of the reflection pulse p _p and detect only the reflection pulse p _{K of the} defect. It is an object of the present invention to provide a method of inspecting a reflection pulse of a partial ROM set on a magneto-optical disk together with a reflection pulse of an ID section to inspect a defect of a DATA section where the partial ROM is not set.

[0006]

SUMMARY OF THE INVENTION The present invention is a magneto-optical disk inspecting method for achieving the above object, wherein a magneto-optical disk having a partial ROM is mounted on a spindle and rotated, and a track is read from the track. A laser spot is emitted from the optical head and the reflected light is received. The address numbers of the track and the sector in which the partial ROM is set, which are prepit-recorded in the SFP portion of the specific track, are read out and stored in the RAM. When the track and sector numbers that are sequentially read as the disk rotates match the address numbers stored in the RAM, the defect detection for the sector of the track is inhibited, and the data part of the sector that does not match the address number. Perform defect inspection for.

[0007]

In the above-mentioned inspection method, the magneto-optical disk is mounted on the spindle and rotated, first, a laser spot is irradiated to a specific track, the reflected light is received, and the track is provided. The address number of the track and the sector in which the partial ROM is set is read from the SFP unit and stored in the RAM. Then, each track is inspected, and the track and sector numbers sequentially read by the rotation of the disk are RA
When the address number stored in M matches, the defect detection for the sector of the track is inhibited.
The defect inspection is performed on the data portion of the sector that does not match the address number, that is, the data for which the partial ROM is not set. From the above, the partial RO
The interference of the M reflected pulses is eliminated and the optical inspection is carried out without any problems.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment in which the magneto-optical disk inspection method of the present invention is configured by a hard circuit. The inspection apparatus is equipped with a partial ROM type magneto-optical disk (hereinafter simply referred to as disk) 1 and is rotated. Spindle 3 to
An optical head 2 for the disk 1 and an inspection unit 4 are included. The inspection unit 4 is configured by connecting a position information read circuit 41, a track / sector read circuit 42, a defect detection unit 43, a microprocessor (MPU) 44, a RAM 45, and a gate signal generation circuit 46 as shown in the figure. The defect detecting section 43 is composed of two comparators 431 and 432, a slice voltage generating circuit 433, and a defect discriminating circuit 434, and is used in a conventional defect inspection apparatus.

A procedure for inspecting the disk 1 having the above structure will be described. The optical head 2 is moved by a carriage mechanism mechanism (not shown) with respect to the rotating disk 1 mounted on the spindle 3 to seek a specific track provided on the outer circumference of the disk and whose number is known in advance. On the other hand, a laser spot is emitted from the optical head 2 and a light reception signal of the reflected light is input to the position information reading circuit 41, and the SFP (standard format) recorded on a specific track.
The address number of the track in which the partial ROM is set and its sector are read out. The read address number is stored in the RAM 45 by the MPU 44 as position information. Then, the defect inspection is performed, the optical head 2 is moved (usually the outer peripheral direction from the inner peripheral track), and the tracks to be inspected are sequentially sought. The received light signal is the defect detection unit 43.
Are input to the two comparators 431 and 432, and the positive slice voltage V _P and the negative slice voltage V _n given by the slice voltage generating circuit 433 are compared, and a light reception signal exceeding these is detected. Both slice voltages V _P and V _n are set in the same manner as in the past. On the other hand, the light reception signal of the optical head 2 is simultaneously input to the track / sector read circuit 42, the track number and its sector number are sequentially read, and compared with the position information stored in the RAD 45 by the MPU 44. When the sequentially read track number and sector number do not match the address number indicated by the position information, the gate signal generation circuit 46 causes the DATA section except the ID section of each sector to be instructed by the measurement command from the MPU 44. The defect measurement gate signal is given to the two comparators 431 and 432, the detection signal detected as described above is input to the defect discrimination circuit 434 to discriminate the defect, and the defect signal is taken into the MPU 44 to be subjected to a predetermined process to perform the defect. Defect data with the track and sector number and the sector number added are output. Further, when the two coincide with each other, that is, in the sector in which the partial ROM is set, the MPU 44 does not give the measurement command to the gate signal generation circuit 46, so that the defect measurement of the sector is inhibited. In the above, the disks copied from the same stamper have the same set positions of the partial ROM, so that the defect inspection can be performed on each of the subsequent disks by using the address number of the partial ROM for the first disk.

Although the above embodiment is based on the hardware configuration, the inhibit of the partial ROM can be performed by the software processing of the MPU 44. In that case, the gate signal generating circuit 46 is unnecessary and the program for the inhibit is used. In either case of hardware or software, the partial ROM is inhibited according to the condition described in claim 1, and the DA of the sector in which the partial ROM is not set is set.
It goes without saying that the present invention is included as long as the defect of the TA portion is detected.

[0011]

As described above, in the magneto-optical disc inspection method according to the present invention, the address number of the track in which the partial ROM is set and the sector number thereof are read from the SFP section provided in a specific track of the disc. When the track and sector numbers sequentially read in the defect inspection match the address number of the position information, the defect detection for the sector of the track is inhibited, and the partial data is not set in the partial ROM. The defect inspection is performed by using the above-mentioned method, which contributes to the defect inspection of the partial ROM type magneto-optical disk.

[Brief description of drawings]

FIG. 1 shows a schematic block diagram of an embodiment of the present invention.

2A is an explanatory view of tracks and sectors of a magneto-optical disk, FIG. 2B is a development view of tracks, FIG. 2C is an explanatory view of track grooves and ID pits to be preformatted, and FIG. 2D is a defect. It is explanatory drawing with respect to the inhibit of the ID part in inspection.

FIG. 3A is an explanatory diagram of a partial ROM set in a magneto-optical disk, and FIG. 3B is an explanatory diagram of problems in the defect inspection.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magneto-optical disk or partial ROM type magneto-optical disk, 2 ... Optical head, 3 ... Spindle, 4 ... Inspection part, 41 ... Position information read circuit, 42 ... Track / sector read circuit, 43 ... Defect detection part, 44 ... Microprocessor (M
PU), 45 ... RAM, 46 ... Gate signal generating circuit, S _0-
S _m , S _r , S _s , S _t ... Sector, V _P , V _n ... Slice voltage.

Claims (1)

[Claims] 1. An arbitrary partial ROM data is pit-recorded in advance in a data section of a predetermined sector of a predetermined track, and an address number of the predetermined track and sector is pit recorded in an SFP section provided in a specific track. Targeting a recorded, partial ROM type magneto-optical disk, the magneto-optical disk is mounted on a spindle and rotated,
A laser spot is emitted from the optical head onto the track of the magneto-optical disk, and the reflected light is received.
The partial ROM pre-recorded in the FP section
The address numbers of the tracks and sectors to which data is set are read out and stored in the RAM, and the track and sector numbers sequentially read out as the magneto-optical disk rotates match the address numbers stored in the RAM. At this time, the defect detection for the sector of the coincident track is inhibited, and the defect inspection is performed for the data part of the sector which does not coincide with the address number.