JPS6159627A - Optical disc device - Google Patents

Abstract

PURPOSE:To shorten the seek time by providing a control part which stores information in a jumpable area and a buffer storage area in the order of seek frequency of information. CONSTITUTION:An optical head 12 is provided for a disc surface E opposite to a disc surface D where only a narrow range of a buffer storage area B including a jumpable area C is accessed by an actuator 13 and an object lens driving actuator omitted in the figure. Data read first in accordance with the instruction of a host computer 11 by an optical head 4 is transferred to the host computer 11, and the actuator 13 is driven to write this data in the jumpable area C by the optical head 12. When the same data is read hereafter, it is read from the jumpable area C in a high speed by the optical head 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disk device, and more particularly to a data access method that shortens data access time.

An optical disk device is a device that optically records and reproduces information by irradiating a laser beam onto a track provided on the surface of a recording medium.Compared to a magnetic disk device, which also records and reproduces information, it Although it has the advantage of having a very large amount of recording capacity, it has the disadvantage of slow data access time.

In recent years, the amount of information processed by computers has continued to increase, and in order to record and reproduce the increased information, optical disk devices with a large recording capacity have attracted attention, and there is a desire for faster access times.

[Conventional technology]

FIG. 3 shows a principle diagram of a conventional optical disc device.

In the figure, 1 is a recording medium, 2 is an objective lens, and together with an optical system 3 constitutes an optical head 4. A laser beam incident from an optical system 3 is focused by an objective lens 2 and irradiated onto a predetermined position of a track provided on the surface of a recording medium (hereinafter referred to as a disk) 1 to record or erase information. It also captures the laser light reflected from the trunk surface and reproduces information. A lens drive actuator 5 changes the optical axis angle of the objective lens 2 and drives the laser beam so that it jumps between predetermined tracks.

Optical system 3 constituting optical head 4 of this optical disc device
In addition to the objective lens 2 that narrows down the laser beam, the system is equipped with an information signal detection system (not shown), and a focus error and tracking/knocking error detection system, whose size and weight depend on the magnetic field of the magnetic disk drive.・Since it is much larger and heavier than the 7D, the seek speed to a predetermined position in the trunk is about 1/10 slower than that of a magnetic disk device.

Also, the recording and playback track width of the optical disc is 171 m.
1730 of the magnetic disk device, accurate track positioning cannot be achieved only by the action of the actuator tough of the head carriage 6 that seeks the entire optical head 4, and after the seek by the head carriage 6, the lens drive actuator 5 drives the laser beam. The light must be moved to access a given track. Therefore,
This has the disadvantage that additional track access time is required.

FIG. 4 shows a block diagram of a conventional access time reduction type optical disc device. In order to make the explanation of the configuration and operation easier to understand, the same parts are given the same reference numerals throughout the drawings and their repeated explanation will be omitted.

In the figure, an area that can be accessed by the laser beam jumping approximately at the center of the surface of the disk 1 (skipping possible area)
Provide C. Areas A on both sides of the jumpable area C are data areas. A head carriage 6 that accommodates an optical helad 4 is driven by an actuator 7. 8 is a disk adapter that controls seek, information change, demodulation, laser beam track access, etc. Reference numeral 9 denotes a buffer memory section, and information from the computer 11 is input to the buffer memory section 9 via the optical disk controller 10.

The buffer memory section 9 reads the information first input from the computer 11 and transfers it to the actuator, and also creates a management table in which the input data address, seek frequency, seek time interval, etc. are written. This management data and information data are recorded on the tracks of the jumpable area C and data area A of the disk 1 via the disk adapter 8.

When reproducing data recorded in this way, the average access time is several milliseconds since the next time the data is directly sent to the computer 11 from within the laser beam jump area C.
This is about 4 to 5 times faster than the highest performance magnetic head.

In addition, when the remaining capacity of the jumpable area C becomes low, referring to the management table created in the buffer memory unit 9, data is erased sequentially starting from the data with the lowest seek frequency (in this case, even if the data is erased, the same content remains The data remains in the data area A), and new data is recorded preferentially, thereby making effective use of the tracks in the jumpable area C.

[Problem that the invention seeks to solve]

According to the conventional example, only one optical head 4 is used to seek the medium surface of the disk 1, so if the jumpable area C overflows, the access time will be significantly degraded. Further, the capacity of the transferable area C is small, for example, in a disk with a diameter of 8 inches, less than 1% of the total capacity on one side, and the hit rate of 90% at which the buffer effect is large cannot be easily achieved.

In order to achieve this, disadvantages are expected, such as the fact that it can only be used with small disks (for example, diameters of 3.5" or less) in which the transferable area C appears relatively large.

In view of the above-mentioned drawbacks of the conventional art, the present invention provides an optical disc device that can speed up the access time by providing a buffer storage area including a jumpable area C on the disc 1 and an optical head dedicated for seeking this area. The purpose is to provide.

[Means to solve the problem]

This purpose is to record information using disk media,
In an optical disc device for reproducing and erasing, a buffer storage area is provided in the center of the data area on the disc medium surface;
In the center of the buffer storage area, an area that can be accessed by jumping the laser beam (skipping possible area) is configured on each side, and at the same time an optical head seeks one data surface, the optical head seeks the data on the other surface. The present invention is characterized in that it is provided with an optical head that seeks the jumpable area or the buffer 1 storage area, and has a control unit that sequentially stores the information in the jumpable area and the buffer storage area in descending order of seek frequency. This is achieved by providing an optical disc device.

[Effect]

In other words, data read and written (hereinafter abbreviated as R/W) from the host computer to the first data area is always read/written to the transferable area and the data area using dedicated optical heads, respectively. , the seek frequency of the data is managed in the buffer memory of the control unit, and the next time the same data is read in a jumpable area with a fast access speed, if the data is not recorded in the jumpable area, it is read in the nearest jumpable area. read from the buffer storage area at a relatively fast access speed.

The buffer memory of the control section always attempts to make effective use of the jumpable area by transferring or erasing data whose seek frequency has decreased from the jumpable area to the buffer storage area.

〔Example〕

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

FIG. 1 shows a disk surface layout of a jumpable area and a buffer storage area according to the present invention.

In the figure, area B is a buffer storage area and data area A
Furthermore, in the center of the buffer storage area B, a jumpable area C is placed on both the front and back sides of the disc 1.

By arranging each area in this way, the transferable area C can be accessed at high speed, and even if the beam cannot be accessed, if it is a narrow area closest to the transferable area C, the travel time of the head carriage can be significantly reduced. It can be shortened.

For example, if the buffer storage area B is located in the center of the data area A of a 12" diameter disk, the stroke is 4 mm (25
00 tracks, 75MB), the average seek time of buffer storage area B can be approximately 1 On+s, and the average seek time of the entire data area A is 200 MB.
It is significantly shortened compared to m5.

Next, the jump possible area C is placed in the center of the buffer storage area B.
Stroke 200μm (130) rack, 4M
If B) is provided, the track seek time due only to jumps can be reduced to an average of 1 to 2 ms, making it extremely fast.

The occupancy ratio of buffer storage area B's capacity ffi75MB is 5%, and the capacity of jumpable area C is 4MB, so the hit rate that only needs to be within jumpable area C reaches 90%, and the number of hits from the host computer increases. When data is read/written using a command, the average seek time is only a few ff1s.

In actual data access, a disk rotation waiting time (16 m5 on average at 1800 rpm) is added to this, but the access time is still reduced to 1/10 compared to the conventional method (approximately 200 m5 + 16 m5).

FIG. 2 shows a side sectional view and a block diagram of an optical disc device according to the present invention. In the figure, the optical head 12 has the function of accessing only a narrow range of the buffer storage area B including the jumpable area C by an actuator 13 and an actuator for driving an objective lens (not shown), and has the function of accessing only a narrow range of the buffer storage area B including the jumpable area C. is provided on the disk surface E, which is the back surface of the disk surface to be accessed.

In order to simplify the explanation, in this embodiment, the configuration is the opposite of the above, that is, an optical head that seeks a narrow range on the disk surface in response to an optical head that seeks the entire disk surface E, and an actuator that accesses both optical heads. The description of is omitted.

The data first read by the optical head 4 according to a command from the host computer 11 is transferred to the host computer 11 side, and the actuator 13 is driven to write the data into the jump possible area C by the optical head 12. When reading the same data from next time onwards, the optical head 12 reads the same data from the jumpable area C at high speed.

When writing data sent from the host computer 11, first, in the same order as explained in FIG.
are read into the buffer memory 9 and transferred to the optical heads 4 and 12 via the actuators 7 and 13, respectively,
The data is stored in a management table that describes the address, seek frequency, seek time interval, etc., and the reading history of the same data is managed thereafter. Further, the data written in the jumpable area C by the optical head 12 is read from the jumpable area C at a high speed by the optical head 12 when the same data is read next time.

The control unit 10 and the buffer memory 9 have a jumpable area C.
When the remaining capacity of the buffer storage area becomes small (when the remaining capacity becomes small), referring to the contents of the management table, data with low seek frequency and data with long usage time intervals in the jumpable area C are allocated to the buffer storage area according to predetermined standards. B, and when the remaining capacity of buffer storage area B becomes low, it is erased according to the same predetermined criteria (in this case, the same data as the erased data is recorded in the data area), and it can always be moved. Effective use of area C and buffer storage area B is attempted.

The above sequence apparently speeds up data recording and reproduction. Management data created in the buffer memory 9 (addresses in the jumpable area C, addresses in the sofa storage area B, addresses in the data area A where these should originally be written, number of seeks, usage time interval, etc.) is recorded in the management table vt area (not shown) approximately at the center of the jumpable area C, for example, in the 3rd to 5th trunks, and before loading the disc 1 into the optical disc device and receiving commands from the host computer, The information is transferred from the management table area in the jumpable area C to the buffer memory 9, and the optical head 4.12 is controlled based on the information.

If this series of management data is changed during R/W, it is necessary to write it from the sofa memory 9 in the form of changing the management table information in the transferable area C before removing the disc 1 from the optical disc device. It is preferable to provide a suitable locking mechanism so that this operation is not forgotten.

In this embodiment, an example has been described in which optical heads are provided on both sides of the disk, but the object of the present invention can be achieved by similar operations when two optical heads are provided on one side of the disk. .

〔Effect of the invention〕

As described in detail above, according to the optical disc device of the present invention, when normal code data is read/written, it is extremely rare for the tg area B of the Hasophoric record to overflow, and the jumpable area C and buffer R with only storage area B
/W reaches 95% of cases, realizing faster seek times.

Further, the above effect can be similarly expected when two fixed heads are arranged on one surface.

[Brief explanation of drawings]

FIG. 1 is a disk surface layout diagram of the jumpable area and buffer storage area according to the present invention, FIG. 2 is a side sectional view and block diagram of an optical disk device according to the present invention, and FIG. 3 is the principle of a conventional optical disk device. 4 is a block diagram of a conventional access time reduction type optical disk device,
shows. In the figure, 1 is a disk, 4 and 12 are optical heads,
9 is a buffer memory, 10 is a control unit, A is a data area,
B is a buffer storage area, C is a jumpable area.Figure 1Figure 2FFigure 3Figure 4

Claims (2)

[Claims] (1) In an optical disk device that records, reproduces, and erases information using a disk medium, a buffer storage area is provided in the center of the data area on the surface of the disk medium, and a laser beam is scattered in the center of the buffer storage area. Areas that can be accessed (jumpable areas) are configured on both sides of the disk, and one optical head is provided on each side of the disk, and one head is made to seek the entire data area on that disk surface. An optical disc device characterized in that the head on the other side sometimes seeks a transferable area or a buffer storage area on the other side. (2) A patent claim characterized in that two optical heads are provided on one side of a disk, and when one head seeks the entire surface, the other head seeks a jumpable area or a buffer storage area. The optical disc device according to scope (1).