JPH07110975A - Magneto-optical disk apparatus - Google Patents

Abstract

PURPOSE:To control a magneto-optical disk apparatus by a single microprocessor by a method wherein a servo control operation which reguires a real-time processing operation is conducted by an interrupt processing operation during the input/output operation of data which is not affected even without being processed in real time. CONSTITUTION:The readout instruction of data from a host computer 17 is read out by an input/output control part 1. At this time, a command is interpreted by a CPU 8 inside a microprocessor 5. Then, a buffer monitoring task which performs a reproducing operation is started by a sequence task. Then, a buffer memory 2 is retrieved, and prescribed data are output to the host computer via the input/output control part 1. At this time, the buffer monitoring task and an input/output task are started sequentially. Then, in an interrupt processing part, an actuator driving signal is sent to a D/A converter 11. In the D/A converter 11, an analog converted signal is sent to an actuator 12-1 or 12-2. Then, when a secondary address is found, a seek operation is conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam for irradiating a light beam emitted from a light source onto a track of a magneto-optical recording medium and applying an external magnetic field to record and / or reproduce information on the medium. The present invention relates to a magnetic disk device.

[0002]

2. Description of the Related Art A general structure of a conventional magneto-optical disk device is as shown in FIG. 13 (Oki Electric Technical Report, No. 1).
No. 48, Vol. 57 No. 4 “Optical Magnetic Disk Unit”). This device configuration includes a drive unit, a control unit, and a power supply unit. The drive unit records the data on the disk and / or reproduces the data from the optical head (actuator 12,
An optical system 14) including a light source, a detector, an objective lens, etc., a signal processing unit 15 which mainly performs modulation of data transferred from the outside of the device at the time of recording and detection / demodulation of data read from a disk, servo control Section 22, medium attaching / detaching mechanism 10,
First for controlling the disk rotation mechanism 9 and the drive unit
Of the microprocessor 23. The control unit is a drive control unit 21 that controls data transfer and drive unit operation from and to the drive unit, and an ECC processing unit 3 that corrects data errors.
1, a buffer control unit 30 for controlling a data buffer, a SCSI controller 1 and a second microprocessor 20 for controlling them.

[0003]

However, in such a conventional magneto-optical disk device, a microprocessor is required for each of the drive section and the control section. Further, although not shown in FIG. 13, naturally, both processors require a memory for storing programs and variables, and such a memory is also required for each of the drive unit and the control unit. there were.
Further, the drive control unit 21 is also required to smoothly control the control unit and the drive unit.

As described above, the conventional magneto-optical disk device requires a plurality of microprocessors and memories and a drive control section, and is therefore expensive and difficult to be miniaturized.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a magneto-optical disk device capable of satisfying the conventional functions with a single microprocessor and being inexpensive and capable of being miniaturized. The purpose is to provide.

And, the above-mentioned object is to record and / or reproduce information on the medium by irradiating a desired track of the magneto-optical recording medium with a light beam emitted from a light source through an optical system. In the apparatus, means for moving the optical system in a direction transverse to the track and a direction orthogonal to the medium surface, means for detecting a tracking error and a focusing error of the light beam, and the means based on the output of the detecting means. And a means for calculating the driving amount of the moving means such that the light beam is irradiated to the track in an appropriate state, and the calculation processing by the calculation processing means collects information transferred from outside the device. During the input / output operation of inputting information into the device and / or outputting information read from a desired track on the medium to the outside of the device. Magneto-optical disk device characterized by being executed crowded.

[0007]

According to the present invention, a servo control operation that requires real-time processing can be executed by an interrupt process while a control operation such as a data input / output operation that does not affect real-time processing is being executed. Allows a single microprocessor to fully satisfy conventional functionality.

[0008]

【Example】

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a magneto-optical disk device of the present invention. Incidentally, FIG.
3, the input / output control unit 1, the buffer memory 2, the disk rotation mechanism 9, the load / eject mechanism 10, the actuator 12, the optical system & sensor 1, which are the same components as those in FIG.
4, the signal processing unit 15, and the disk 16 are given the same numbers.

In the present embodiment, in addition to this, an internal memory (built-in RO) provided in the same chip as one CPU 8 is provided.
A single microprocessor 5 composed of M6, built-in RAM 7), an error detector 13 for detecting a position error signal of a light beam from an external ROM 3, an external RAM 4 and an optical system 14 for storing programs and variables, respectively. It has an A / D, D / A converter 11 for converting the error signal from the error detector into a digital signal and converting the control signal from the microprocessor 5 into an analog signal. The buffer control unit 30, the ECC processing unit 31, and the power supply unit 32 shown in the conventional example are not shown in this embodiment. Further, the servo control unit 22 in FIG. 10 corresponds to the microprocessor 5, the A / D, the D / A conversion unit 11 and the error detector 13 in this embodiment, and in this embodiment,
The servo control consists of digital servo control.

To explain further, the actuator 12-1
Is a tracking actuator that moves a focusing objective lens (not shown) provided in the optical system 14 in the radial direction of the magneto-optical disk 16 and a focus that moves the objective lens in a direction perpendicular to the surface of the optical disk 16. It is an actuator. The optical system 14 and these two actuators are incorporated in an optical head and are configured to be movable in the radial direction of the optical disc 16. Reference numeral 12-2 is a linear motor for moving the optical head in the radial direction of the optical disk 16. A tracking / focus error detector 13 detects a tracking / focus error signal based on the output of the sensor in the optical system 14. Each signal detected here is converted into a digital signal in 11 A / D converters and then output to the CPU 5.

Reference numeral 17 is a host computer, which is a host device for issuing commands such as recording / reproducing to the magneto-optical disk of the present invention. In this embodiment, the magneto-optical disk device of the present invention is used as an external storage device of the host computer. Has become. The input / output control unit 1 receives an instruction from the host computer 17 and sends the instruction to the microprocessor 5.

The microprocessor 5 forms the main control unit of the magneto-optical disk apparatus of this embodiment, and temporarily stores the record data transferred from the host computer 17 in the buffer memory 2 in the apparatus and at the same time. The recording / reproducing data input / output operation of supplying the recording data from the buffer memory 2 to the optical head and / or outputting the reproducing data read from the magneto-optical disk by the optical head to the host computer 17 The output operation is also referred to as a recording / reproducing operation), the position control operation of the light beam (including the tracking / focusing operation), the speed control in the seek control, and the like are performed.

Next, the operation of this embodiment based on the above configuration will be described.

FIG. 2 is a conceptual diagram of a program configuration built in the microprocessor 5 in this embodiment.
It is a task management type configuration based on a real-time monitor (synonymous with a real-time OS). For example, when the input / output control unit 1 receives a recording command from the host computer 17, the sequence task that manages the tasks in the task unit raises the activation priority of the input / output tasks in the figure, and simultaneously executes the input / output tasks. To start. The input / output task receives a command from the input / output control unit 1 and interprets the command. At this time, other tasks are in a standby state or in a stopped state. Servo control such as focus / tracking is time-divisionally processed in parallel by interrupt processing at this time. When the command input / output processing is completed, the sequence task lowers the priority of the input / output task and activates another task with a higher priority. In this embodiment, recording / playback operation control, load / eject control, and
The control that requires real-time processing such as tracking servo control, focusing servo control, and seek control that executes error processing of the magneto-optical disk device is apparently parallel to task execution in a time-divisional processing mode (interrupt processing). To execute.

FIG. 3 conceptually shows the structure of an interrupt processing unit for performing the above-mentioned interrupt processing. In this embodiment, the NM
When the servo interrupt process execution unit is called at a predetermined cycle by an interrupt caused by I (interrupt mask prohibition interrupt) and a predetermined operation ends, the end state is stored in the internal memory, and the status interrupt is set and processed. To finish. Further, regarding the error during execution of the servo interrupt process (servo error, abnormal temperature rise in the device, etc.), error information is similarly set in the internal memory, the status interrupt is set, and the process is ended. The task part higher than the interrupt process execution part activates the related task by this status interrupt command. For example, when the seek control being executed by the interrupt processing execution unit is normally completed, the task unit starts the servo task shown in FIG. 2 and fetches the end status to end the post-analysis task. Also, when an error occurs, an error processing task is started, the status is fetched, and recovery processing is performed according to the status status.

Next, a specific operation of this embodiment will be described. FIG. 4 is a flowchart showing the reproducing operation of the magneto-optical disk device as an example. The operation will be described with reference to FIGS.

A data read command from the host computer 17 is read by the input / output control unit 1 (s1). At this time, as described above, the input / output task is activated and executed. That is, the command is interpreted by the CPU 8 in the microprocessor 5 (s
2). Next, the input / output task is stopped, and the buffer monitoring task for performing the reproducing operation is activated by the sequence task. Then, when the buffer monitoring task is activated, it is first checked whether prefetching is performed (s3). This is to check whether or not the desired data already exists in the buffer memory 2. Next, if there is any, the buffer memory 2 is searched (s4), and predetermined data is output to the host computer via the input / output control unit 1. At this time, the sequence task sequentially activates the buffer monitoring task to the input / output task. If not prefetched in s3, the buffer monitoring task determines the seek operation, simultaneously issues a command to that effect to the interrupt processing unit, and the interrupt processing unit switches the operation mode to the seek operation mode based on the command ( s6). Incidentally, the servo control operation is executed in the interrupt processing unit even during the execution of the processing up to this point, and the operation shown in the flowchart of FIG. 7 is executed in a time division manner. In this embodiment, the time division interval is 20 [μsec]. The specific operation of the interrupt processing unit will be described later. Further, the operation mode in the interrupt processing unit has been switched to the seek operation mode, but in the task unit, the buffer monitoring task continues to perform address calculation (s
7). This address calculation is a primary address in which the direction and distance to which the optical head should move from the target address is simply calculated by the CPU 8, and a secondary address calculation in which the physical address is calculated accurately from the logical address to obtain the distance to move. However, after calculating the primary address, the information is sent to the interrupt processing unit. In response to this result, the interrupt processing unit D
An actuator drive signal for moving the head is sent to the / A converter 11. The D / A converter 11 converts the digital signal into an analog signal and sends the analog signal to the actuator 12-1 or the actuator 12-2. Here, the CPU 8 controls so that the drive signal is supplied to the actuator 12-1 when the moving distance is small, and the drive signal is supplied to the actuator 12-2 when the moving distance is large. When the secondary address is obtained in the address calculation s7, the seek operation by the full-scale speed control method is executed. Here, the servo task is in a standby state, that is, until the seek end status interrupt from the interrupt processing unit arrives, the task unit operates another task having a higher priority of activation. For example, the replacement processing task and the buffer monitoring task are operated.

Next, the operation of the interrupt processing unit in the seek operation mode will be described in detail with reference to the flowchart of FIG. As described above, the time division operation in this embodiment is 2
It is executed every 0 [μsec], and when an interrupt occurs, the focus control operation is first performed (s21). Here, the focus position error signal obtained from the error detector 13 is converted into a digital signal in the A / D conversion unit 11, the signal is taken into the microprocessor 5, and based on the signal, the built-in CP is calculated by a predetermined arithmetic expression in the ROM and a predetermined parameter in the built-in RAM.
The focus control signal is calculated by U8, and the D / A converter 11
Then, a drive signal is output to the actuator 12-1.
Next, the track count is read (s22). This track count is made from the tracking error signal obtained from the error signal detector 13, is pulsed by a binarization circuit (not shown), and is counted by a counter (not shown). The counter may be built in the microprocessor 5. Next, this track count value is compared with the target track count value (s23), and if they match, that is, if the optical head has reached the target position, the operation mode is set to, for example, the track shown in FIG. After changing to the follow-up mode (s28) and storing the seek end status in the internal RAM 7 (s29), the process ends. If they do not match in s23, the target speed Vref is calculated from the current track count (s24), and the current speed Vn is calculated (s25). The speed control method executed in this embodiment will be described later. Based on the respective calculated values, the seek control amount is calculated based on the calculation formula stored in the built-in ROM (s26). And D /
It is output to the actuator 12-2 via the A converter 11 (s27). Here, when the moving distance is small, the CPU 8 outputs a command to the actuator 12-1 and when the moving distance is large, a command to the actuator 12-2. The above operation is repeated until the track count value and the target track count value match in s23.
Repeat every 0 [μsec]. Then, if the track count value and the target track count value match at s23, the operations of s28 and s29 described above are sequentially performed, and the interrupt process is ended. After the interrupt processing is completed,
The processing moves to the task section. The task section continues to execute the task that was being executed before the execution of the interrupt process. After that, when an interrupt occurs again, s2
The interrupt processing from 1 to s27 is executed.

Next, when the seek operation ends and a status interrupt occurs in s29, the servo task in the standby state is activated and the target address confirmation operation of s8 in FIG. 4 is executed. At s8, an address is detected by the signal processing unit from the signal read by the optical head from the magneto-optical disk 16, and if the microprocessor 5 checks whether the addresses are the target addresses, the servo task is ended and the buffer is terminated. The monitoring task is activated and data reading is started (s8). If not, the seek operation is executed again. Then, the data detected by the signal processing unit 15 from the signal read from the magneto-optical disk 16 by the optical head is processed by the buffer monitoring task.
The data is transferred to the buffer memory 2 and is sequentially output to the input / output control unit 1 (s11). When the predetermined data is transferred, the read operation ends and the idle task is activated.

FIG. 6 shows a flowchart of the operation of the idle task. The task units other than the interrupt processing unit are in a work waiting state (s31). The interrupt processing unit at this time is executing the track following operation, and a flowchart of the operation is shown in FIG.

When an interrupt command is input, the focus position error signal and the tracking error signal obtained from the error detector 13 are converted into digital signals in the A / D converter 11, and the signals are fetched into the microprocessor 5 (s4
1) Then, based on the signal, the CPU 8 calculates a focus control signal and a tracking control signal (s42) by a predetermined arithmetic expression in the built-in ROM and a predetermined parameter in the built-in RAM, and the D / A A drive signal is output to the actuator 12-1 via the converter 11 (s43).
Here, in the focus control and the tracking control, in the present embodiment, the tracking operation is first calculated, and then the focus control operation is executed.

Next, an example of the above speed control system will be described.

As a speed control method, a method is generally used in which the speed of the head is sequentially monitored and seek is performed according to a predetermined running schedule. FIG. 8 is a diagram showing the relationship between the reference speed and the actual speed in the speed control method, and the coarse actuator applied current for driving the carriage. In the figure, the reference speed Vref represents the speed at which the head is scheduled to travel, and is calculated according to the residual distance to the target position.
The reference speed Vref is calculated by the following equation.

Vref = (2 · α (S−λ / 2 · N)) 1/2 (1) In the formula (1), S is the target moving distance, λ is the track pitch, α is the deceleration acceleration, and N is the deceleration. Is the zero cross count value. Further, in order to make the head speed follow the reference speed, the current speed of the head is sequentially detected. The speed is generally detected by dividing the current speed Vn of the head into a high speed region and a low speed region.

That is, in the high speed region, the track count method is used and the number of tracks N traversed by the head within a predetermined sampling interval Ts is obtained.

Vn = (λ / 2 · N) / Ts (2) In the low speed range, the track-counting method is used to detect the zero-cross point of the tracking error signal, and the time Td from this zero-cross point to the next zero-cross point is calculated. To measure. In this case, the distance between the zero cross points is 1 of the track pitch λ.
Therefore, the speed at this time can be obtained by the following equation (3).

Vn = (λ / 2) / Td (3) Here, the speed detection method is selected by using the speed detection method based on the equation (2) when the speed is faster than a predetermined speed value, and when the speed is slower than the predetermined speed value. The speed detection method based on the equation 3) is selected.

When controlling the speed of the head, the command value of the actuator is calculated from the difference between the current speed and the target speed at that time at regular intervals, and the speed of the head is controlled by the obtained command value.

As described above, the relative velocity between the disk surface and the head is sequentially detected by using the track count and the tracking error signal, and the head is sequentially controlled according to the target velocity calculated from the equation (1). In particular, the target speed Vref as shown in FIG. 8 is prepared in advance in the memory as a target speed table in the digital servo apparatus of this embodiment. This target speed table stores the speed value obtained from the (remaining track) equation (1) for the remaining distance.

By the speed control system as described above, the head is sought to the target position according to a predetermined operation schedule.

[Second Embodiment] A second embodiment of the present invention will now be described in detail with reference to the drawings. The configuration of the device is the same as that of the first embodiment, so the description is omitted.

FIG. 9 is a conceptual diagram of the program structure in this embodiment. Similar to the above embodiment, the task management type is based on a real-time monitor (synonymous with a real-time OS). In the present embodiment, in addition to the servo control operation shown in the above-mentioned embodiment, in the operation in the interrupt processing unit,
Includes spindle monitoring and emergency error handling.
This is a proper arrangement in place, such that processing that requires real-time processing is executed by interrupt processing, and processing that does not need to be processed in real time is executed by the task unit.

Now, a specific operation will be specifically described based on a flowchart.

FIG. 10 shows the operation of the spindle control task, and FIG. 11 shows the operation of spindle monitoring in the interrupt processing section. In the flowchart shown in FIG. 11, the track following operation is first performed as described with reference to FIG. 7 (s61-s63). Then, the time of one rotation is counted based on the spindle rotation signal (6 shots per rotation) output from the spindle rotation mechanism 9 (s6
4). Then, the interrupt processing ends. Such a series of operations is executed next to the servo control operation for each interrupt. On the other hand, in the task part, the spindle control task reads the spindle count, which is one rotation time of the spindle (s51), checks whether it is within a predetermined range (s52), and ends if it is within the range, otherwise it is not. For example, the error processing task is activated (s53).

As shown in the above operation, the operation for measuring the time interval fairly accurately needs to be executed by the interrupt processing. Further, the emergency error process as shown in FIG. 9 is also a process to be executed by the interrupt process. Figure 1
2 shows a flowchart. If the focus is out of focus due to external vibrations or scratches on the disk during the track following operation as shown in FIG. 7, all servo operations must be stopped urgently. Then, the operation of s71 is executed in the interrupt process to perform an interrupt process such as setting an error status (s72).

[0036]

As described above, according to the present invention, the input / output operation, the replacement processing operation, and the load / eject operation which have no effect even if the servo control operation requiring real time processing is not processed in real time are performed. The control unit and the drive unit can be controlled by a single microprocessor by executing the interrupt process while the control operation such as the operation is being executed. As a result, it is possible to provide a magneto-optical disk device that is inexpensive and can be downsized without the need for a drive control unit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a magneto-optical disk device of the present invention.

FIG. 2 is a conceptual diagram of a program configuration constructed in the microprocessor 5 of the first embodiment of the present invention.

FIG. 3 is a diagram conceptually showing the structure of an interrupt processing unit according to the first embodiment of the present invention.

FIG. 4 is a flow chart showing the operation of the task unit during data reproduction in the first embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the interrupt processing unit during a seek operation in the first embodiment of the present invention.

FIG. 6 is a flow chart showing an operation of a task unit at the time of idling in the first embodiment of the present invention.

FIG. 7 is a flowchart showing an operation of an interrupt processing unit at the time of track following operation in the first embodiment of the present invention.

FIG. 8 is a speed control method 1 according to the first embodiment of the present invention.
It is a figure for explaining an example.

FIG. 9 is a conceptual diagram of a program structure constructed in the microprocessor 5 of the second embodiment of the present invention.

FIG. 10 is a flowchart showing the operation of the task unit during spindle control in the second embodiment of the present invention.

FIG. 11 is a flowchart showing a track following operation and an operation of an interrupt processing unit during spindle monitoring in the second embodiment of the present invention.

FIG. 12 is a flowchart showing an operation of an interrupt processing unit in emergency error processing according to the second embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a conventional magneto-optical disk device.

[Explanation of symbols]

1 Input / Output Control Unit 2 Buffer Memory 3 External ROM 4 External RAM 5 Microprocessor 6 Built-in ROM 7 Built-in RAM 8 CPU 9 Disk Rotation Mechanism 10 Load / Eject Mechanism 11 A / D, D / A Converter 12-1 Focus Actuator and Tracking actuator 12-2 Linear motor 13 Error detector 14 Optical system 15 Signal processing unit 16 Optical disk 17 Host computer 20, 23 Microprocessor 21 Drive control unit 22 Servo control unit 30 Buffer control unit 31 ECC processing unit 32 Power supply unit

Claims (2)

[Claims] 1. A magneto-optical disk device for recording and / or reproducing information on the medium by irradiating a desired track of the magneto-optical recording medium with a light beam emitted from a light source via an optical system, A means for moving the optical system in a direction traversing the track and a direction orthogonal to the medium surface; means for detecting a tracking error and a focusing error of the light beam; and the light beam based on the output of the detecting means. And a means for arithmetically processing a driving amount of the moving means for irradiating the track in an appropriate state. The arithmetic processing by the arithmetic processing means stores information transferred from outside the apparatus into the apparatus. Executed by interrupting during input / output operation of inputting and / or outputting information read from a desired track on the medium to the outside of the device Magneto-optical disk apparatus characterized and. 2. The apparatus according to claim 1, wherein the arithmetic processing means further executes speed control when the light beam seeks to a desired track.