JPH05159451A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To shorten the time to reach a target revolving speed and to highly accelerate the whole seek speed by conducting a current for acceleration or deceleration in a driving coil when seeking of a head is performed over a zone. CONSTITUTION:A recording area of a discoid information recording medium 1 is divided into plural zones in the radial direction, and information is recorded or reproduced by changing the revolving speed of the recording medium 1 in corresponding to the individual zones. In this case, a spindle motor 2 for rotatively driving the recording medium 1 is provided with a coil T2 for acceleration and deceleration. Then, when the recording or reproducing head 3 is operated to seek over the zone, and in such a case that a zone to be sought is a zone on the side of higher speed than the present zone, a switch 11 for acceleration is turned on by a comparison circuit 10 to electrify the coil T2 from a power source E1 for acceleration. Then, when seek is performed from an outer circumference to an inner circumference, a switch 12 for deceleration is turned on by the comparison circuit 10 to electrify the coil T2 from a power source E2 for deceleration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus using a disc-shaped information recording medium such as a magneto-optical disc or a magnetic disc.

[0002]

2. Description of the Related Art Conventionally, ZCAV or MCA has been used as a method for increasing the recording density of a disc-shaped information recording medium.
A method called V is known. In this method, the number of revolutions of the disc is constant, and the recording / reproducing frequency is switched according to the zones divided into a plurality of discs. That is, by increasing the recording / reproducing frequency toward the outer peripheral zone of the disc, the spatial recording density is made constant, and the disc capacity can be increased. Further, according to this method, it is possible to increase the capacity by about 50% as compared with the CAV method in which the rotation speed is constant. However, the above ZCAV (M
The CAV method has a problem that the transfer rate changes depending on the reproduction position of the disc. On the other hand, in the ZCLV system, the recording / reproducing frequency is constant, and the rotational speed of the disk is switched in correspondence with the zone to make the spatial recording density approximately constant. In the ZCLV method, the transfer speed is constant regardless of the reproduction positions on the inner and outer circumferences of the disc.

[0003]

However, in the above ZCLV system, when the recording or reproducing head seeks over the zone, the rotation speed of the spindle motor for driving the disk corresponds to a new zone after the seek. It takes time to reach the rotation speed. That is, there is a problem that the time required to reach the new rotation speed of the spindle motor is longer than the seek time of the head, and the time required for the entire seek operation is long.

The present invention has been made in order to solve such a problem, and shortens the time required to reach the rotation speed corresponding to the zone of the motor, and makes it possible to perform high-speed seek of the head for information recording. It is intended to provide a reproducing device.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to divide a recording area of a disc-shaped information recording medium into a plurality of zones in the radial direction, and to change the rotation speed of the recording medium corresponding to each zone. In an information recording / reproducing apparatus for recording or reproducing information by providing a motor for rotatively driving the recording medium with an acceleration / deceleration coil, when the information recording / reproducing head seeks across a zone,
This is achieved by an information recording / reproducing apparatus characterized in that a current for acceleration or deceleration is applied to the coil depending on whether the seek zone is a zone on the high speed side or a zone on the low speed side with respect to the current zone.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the information recording / reproducing apparatus of the present invention. In FIG.
Reference numeral 1 is a magneto-optical disk (hereinafter, simply referred to as a disk) which is an information recording medium, and 2 is a spindle motor for rotationally driving the disk 1. The recording area of the disk 1 is divided into a plurality of zones in the radial direction, and the spindle motor 2 switches the rotation speed corresponding to the zone. That is, in the present embodiment, the recording / reproducing of information is performed with the linear velocity of the disk 1 being approximately constant in any zone.
The CLV method is adopted. In addition to the steady rotation coil T ₁ , the spindle motor 2 includes an acceleration / deceleration coil T _1.
As will be described later in detail, the acceleration / deceleration coil T ₂ accelerates or decelerates the spindle motor 2 when the optical head seeks across the zone, and the time until the rotation speed reaches the target speed is set. Acts to shorten. Three
Is an optical head for recording information on the disc 1 or reproducing the recorded information, which is driven by a linear motor (not shown).
It is configured to be movable in the radial direction of the disc 1.

Reference numeral 4 is a signal reproducing circuit for reproducing the information optically detected by the optical head 3 into an electric signal, and 5 is for detecting the radial position of the disk 1 from the address information obtained by the signal reproducing circuit 4. A radius detection circuit 6 is a rotation speed switching circuit for switching the rotation speed of the spindle motor 2 in response to the radial position and a seek command from the host controller. The rotation speed switching circuit 6 changes the rotation speed of the spindle motor 2 in accordance with the zone by switching the switch 7 and changing the reference value given to the differential circuit 8. In this embodiment, the target rotation speeds are X ₁ = 3000 rpm and X ₂ = 36.
It is switched in three stages of 00 rpm and X ₃ = 4800 rpm. Further, 9 is an encoder for detecting the rotation speed of the spindle motor 2, the output of which is fed back to the differential circuit 8, and the differential circuit 8 uses the steady rotation coil based on the difference between the target rotation speed and the detected rotation speed. By driving T ₁ , the rotation speed of the spindle motor 2 is controlled to reach the target value. Further, reference numeral 10 is a comparison circuit which is activated by an instruction from the rotation speed switching circuit 6 and compares the target rotation speed with the detection value of the encoder 9 and controls the acceleration switch 11 and the deceleration switch 12 according to the comparison result.

Next, the operation of this embodiment will be described. First,
When the seek operation is instructed to the optical head 3 from the host controller, the rotation speed switching circuit 6 crosses the zone from the current zone to another zone according to the current address and the target address detected by the radius detection circuit 5. Determine if it is a seek. At this time, if the zone is not exceeded, the switch 7 is kept as it is to maintain the currently selected target rotation speed, and the switch 13 is kept turned on to keep the speed control loop in the closed state. As a result, the spindle motor 2 maintains the current rotation speed, and the optical head seeks to the instructed track in the current zone in this state. On the other hand, when it is determined that the speed exceeds the zone, the rotation speed switching circuit 6 selects the target rotation speed corresponding to the new zone by the switch 7, simultaneously turns off the switch 13 and activates the comparison circuit 10. As a result, the speed control loop is opened, and the comparison circuit 10 switches the switch 7 in this state.
The target rotation speed selected in step 3 is compared with the actual rotation speed detected by the encoder 9. In this case, when the seek zone of the optical head is on the inner circumference side of the current zone and the current rotation speed is smaller than the target rotation speed, the comparison circuit 10 turns on the acceleration switch 11 to turn on the acceleration power supply. Energize the acceleration / deceleration coil T ₂ from E ₁ . As a result, current is supplied to the acceleration / deceleration coil T _2, and the rotation speed of the spindle motor 2 is rapidly accelerated.

FIG. 2A shows the number of revolutions of the spindle motor 2 when the optical head seeks across the zone as described above. Here, the original number of revolutions is X ₃ (2400r).
pm), the target speed corresponding to the new zone is X ₂ (36
00 rpm). At the same time when the seek operation of the optical head is started, the spindle motor 2 is rapidly accelerated by the above-described acceleration operation and rises toward the target speed. Also, FIG. 2 (b) current i ₁ of the steady rotation coil T _1, FIG. 2 (c) is a current i ₂ of the deceleration coils T _2. In this way, when the rotational speed of the spindle motor 2 suddenly increases and eventually the detected rotational speed of the encoder 9 matches the target rotational speed, the comparison circuit 10 turns off the acceleration switch 11 and stops the acceleration operation of the spindle motor 2. Further, the switch 13 is turned on, the speed control loop is closed again, and the speed control operation at the target rotation speed corresponding to the new zone is started. On the other hand, as shown in FIG. 2A, the optical head has completed the seek operation on the target track immediately before the spindle motor 2 reaches the target rotation speed, and when the spindle motor 2 reaches the target rotation speed, Recording or reproduction of information on the target track is started.

Further, when the zone where the optical head 3 seeks is on the outer peripheral side of the current zone and the current rotational speed of the spindle motor 2 is higher than the target rotational speed of the new zone, the comparison circuit 10 decelerates. Switch 12 on,
Energizing the deceleration power source E ₂ in the coil T ₂ for acceleration and deceleration.
As a result, the acceleration / deceleration coil T ₂ is supplied with a deceleration current in the direction opposite to that during acceleration, and the spindle motor 2 is rapidly decelerated. When the rotation speed of the spindle motor 2 reaches the target rotation speed corresponding to the new zone, the comparison circuit 10 turns off the deceleration switch 12 to stop the deceleration operation of the spindle motor 2. At the same time, the switch 13 is turned on to close the speed control loop, and the speed control operation at the target speed corresponding to the new zone after the seek is restarted. Of course, the optical head 3 reaches the target track before the spindle motor 2 reaches the target rotation speed, and similarly as described above, waits for the spindle motor 2 to reach the target rotation speed and starts recording or reproducing information. To be done.

As described above, in this embodiment, when the optical head seeks to another zone beyond the current zone, the zone position to seek to the acceleration / deceleration coil T ₂ provided in the spindle motor 2 is set. In order to supply the current for acceleration or deceleration in accordance with the above, the time required to reach the target rotation speed corresponding to the zone of the spindle motor 2 can be greatly shortened compared to the conventional case. Therefore, when the head seeks to another zone, the seek time is almost determined only by the original seek time, so that the seek time of the entire head can be remarkably speeded up, and the seek time can be set to the disk rotation speed. ZCL that is decided by switching time
It is possible to effectively solve the problem of the V method.

In the above embodiment, the comparison circuit turns off the acceleration switch and the deceleration switch when the current rotation speed of the spindle motor matches the target rotation speed.
The time may be set in advance without being limited to this, and the switch may be turned off when the acceleration time and the deceleration time reach the set time. Further, in the embodiment, a magneto-optical disk device using a magneto-optical disk has been described as an example, but it is of course applicable to a device using another disk-shaped recording medium such as a magnetic disk.

[0013]

As described above, according to the present invention, the switching time to the target number of revolutions corresponding to the zone of the disk-shaped recording medium at the time of seek operation over the zone of the head can be greatly shortened as compared with the conventional case. This has the effect of significantly speeding up the seek time of the entire head.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an information recording / reproducing apparatus of the present invention.

FIG. 2 is a time chart showing the rotational speed of the spindle motor, the current of the coil for steady rotation, and the current of the acceleration / deceleration coil when the optical head of the embodiment of FIG. 1 is seeking.

[Explanation of symbols]

1 Magneto-optical disk 2 Spindle motor 3 Optical head 5 Radius detection circuit 6 Rotation speed switching circuit 7, 13 Switch 8 Differential circuit 9 Encoder 10 Comparison circuit 11 Acceleration switch 12 Deceleration switch T ₁ Steady rotation coil T ₂ Acceleration / deceleration Coil

Claims (1)

[Claims] 1. Information for recording or reproducing information by dividing a recording area of a disc-shaped information recording medium into a plurality of zones in a radial direction and changing a rotation speed of the recording medium corresponding to each zone. In the recording / reproducing apparatus, a motor for rotating the recording medium is provided with a coil for acceleration / deceleration, and when the information recording / reproducing head seeks beyond the zone, the seek zone is relative to the current zone. An information recording / reproducing apparatus, wherein an electric current for accelerating or decelerating is supplied to the coil depending on whether the zone is on the high speed side or the low speed side.