JPH04178976A - Method for reading data from magneto-optical disk - Google Patents

Abstract

PURPOSE:To read continuous data recorded in a plurality of continuous sectors at a high speed by collectively reading data from substitute sectors for defective sectors and expanding the data read from the substitute sectors in a random access memory. CONSTITUTION:Data are successively read from sectors where data 1 are recorded and expanded at predetermined address of a RAM 20. Even when defective sectors SD exist, the data are read and expanded in the RAM 20 to the final sector of a plurality of continuous sectors without moving a magneto-optical head 15 to the substitute sectors for the defective sectors SD. After reading the data from the final sector, the proper data 3 and 8 recorded in the substitute sectors are read by, for example, moving the head 15 to the substitute sectors and the defective data 3' and 8' in the RAM 20 are replaced with the proper data. Therefore, the continuous data recorded in the plurality of continuous sectors can be read in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for reading data from a magneto-optical disk, in which continuous data recorded in a plurality of consecutive sectors of the magneto-optical disk is read and expanded into a random access memory.

[Prior Art] A magneto-optical disk device is a storage device with a large storage capacity like a conventional write-once optical disk device, but it is capable of rewriting and erasing information, which is not possible with a write-once optical disk device. In recent years, a variety of products related to magneto-optical disks have been released, and magneto-optical disk technology is about to reach the stage of commercialization from the prototype stage.

As described above, magneto-optical disk devices have great expectations as the next generation of large-capacity storage devices, but since magneto-optical disks have extremely large capacities, they are subject to the existence of a certain degree of defects. . For this reason, the method for detecting and correcting defects in magneto-optical disks is
, and countermeasures have been taken. That is, when a defective sector is detected during data recording, data to be written in the defective sector is recorded in a replacement sector provided in a predetermined area (for example, the innermost circumference area) within the magneto-optical disk. Management information regarding alternate sectors is recorded in a predetermined area within the magneto-optical disk.

When reading data recorded in this manner, a designated sector of a designated track is accessed to read the data, and when a defective sector occurs, a replacement sector is accessed and the data is read.

[Problems to be Solved by the Invention] Conventionally, even when reading continuous data recorded in a plurality of consecutive sectors, the magneto-optical head is moved from the defective sector to the replacement sector area every time there is a defective sector. I am trying to read the data. Therefore, each time a defective sector occurs, the magneto-optical head must move back and forth between the tracks of a plurality of sectors in which data has been recorded and the track of the replacement sector, resulting in the problem that it takes time to read data.

An object of the present invention is to provide a method for reading data from a magneto-optical disk that can read continuous data recorded in a plurality of consecutive sectors at high speed.

[Means for Solving the Problem 1] The above object is to provide a method for reading data from a magneto-optical disk in which continuous data recorded in a plurality of consecutive sectors of a magneto-optical disk is read and developed in a random access memory. reading a sector, expanding the continuous data recorded in the plurality of consecutive sectors to a predetermined address of the random access memory; reading a replacement sector for the defective sector in the plurality of consecutive sectors; This is achieved by a method for reading data from a magneto-optical disk, which is characterized in that data read from a magneto-optical disk is expanded to an address in the random access memory assigned to data to be recorded in the defective sector.

[Function] According to the present invention, sectors replacing defective sectors are read all at once and expanded to the random access memory, so the seek time of the magneto-optical head is minimized.
Continuous data recorded in multiple consecutive sectors can be read at high speed.

[Embodiment] A method for reading data from a magneto-optical disk according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Magneto-optical disk device 1 as an external storage device for CPUl0
2 is provided. In the magneto-optical disk device 12, a magneto-optical disk 13, which is a recording medium, is rotated by a motor 14, and a magneto-optical head 15 records or reads data. A magnet 16 is provided on the magneto-optical disk 13 for applying a magnetic field.

As shown in FIG. 2(a), the magneto-optical disk 13 is provided with a large number of tracks, and each track is divided into a plurality of sectors. For example, in the case of a 5-inch magneto-optical disk 13, 18,751 tracks are provided, and each track is divided into 17 sectors.

When cpuio records or reads data on the magneto-optical disk device 12, it outputs an ID number indicating the access position of the magneto-optical disk 13 to the magneto-optical disk device 12. The ID number is the track number T (0 to 18750
) and sector number S (0 to 16),
The magneto-optical disk device 12 records or reads data at a position specified by an ID number.

Further, a RAM (random access memory) 20 is provided in the CPU10. Transfer the data stored in the RAM 20 and record it on the magneto-optical disk device 12,
The data read from the magneto-optical disk device 12 is stored in the RAM.
It is expanded to 20 and stored. An address signal indicating the storage location is output from CPU10, and RAM2
You can freely specify the storage location within 0.

Next, a method of reading data from a magneto-optical disk according to this embodiment will be explained with reference to FIG.

As shown in FIG. 2(a), continuous data ku0〉, ku1〉,
ku2〉, ..., ku1o〉 are recorded.

However, since the sector in which data 3> and data 8> are to be written is the secondary defective sector SD, data 3> and data 8> are written in the innermost replacement sector. Now, the operation when reading the continuous data <0>, <1>, ku2>, ..., ku1o> written across multiple consecutive sectors and expanding it to a predetermined address in the RAM 20 will be explained as an example.

First, the magneto-optical reader 15 is moved to the beginning of a plurality of consecutive sectors, and data is sequentially read from the sector in which data 1> is recorded, and expanded from a predetermined address in the RAM 20. If there is a defective sector SD, the magneto-optical head 1
The data is read up to the last sector of a plurality of consecutive sectors without moving 5 to the alternate sector, and the read data is developed in the RAM 20 as shown in FIG. 2(b). At this time, defective data read from the defective sector 3〉′,
8〉' is not correct data, but it is expanded as is in the RAM 20 without distinction.

Next, the magneto-optical head 15 is moved to the alternate sector and the correct data recorded in the alternate sector is read, and the defective data in the RAM 20 is read as shown in FIG. 2(c). Enter the correct data for <3>' and <8>'.
8> and fix it.

In this way, according to the present embodiment, data is read from a plurality of consecutive sectors excluding defective sectors and expanded into the RAM, and then data is read from a replacement sector and expanded into the RAM. Only a minimum number of seek operations are required, and continuous data recorded in a plurality of consecutive sectors can be read in a short time.

[Effects of the Invention] As described above, according to the present invention, sectors replacing defective sectors are read in batches and are expanded to the random access memory, so the seek time of the magneto-optical head is minimized. Continuous data recorded in multiple consecutive sectors can be read at high speed.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of a method for reading data onto a magneto-optical disk according to an embodiment of the present invention. In the figure, 10...CPU 12...Magneto-optical disk device 13...Magneto-optical disk 14...Motor 15...Magneto-optical head 16...Magnet 20...RAM Direction of rotation of the disk ( α) 28th version)

Claims (1)

[Scope of Claims] 1. A method for reading data from a magneto-optical disk, which reads continuous data recorded in a plurality of consecutive sectors of a magneto-optical disk and develops it in a random access memory, comprising: reading the plurality of consecutive sectors; The continuous data recorded in the continuous plurality of sectors is expanded to a predetermined address of the random access memory, the replacement sector of the defective sector in the continuous plurality of sectors is read, and the data read from the replacement sector is transferred to the A method for reading data from a magneto-optical disk, characterized in that data is expanded to an address in the random access memory assigned to data to be recorded in a defective sector.