JPH09282602A - Information recordor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce moment of inertia and the torque required for starting rotation in an information recording device which holds information in a disk- shaped recording medium by using a recording medium whose thickness is different between the inner periphery section and the outer one. SOLUTION: The thickness of the disk-shaped substrate 100 holding information is different depending on its radial position and, in genral, a relation: ti<=t0 holds, where ti is the disk thickness of the inner peripery section and t0 that of the outer periphery. The substrate 100 rotates around the spindle 101 and, at the same time, the magnetic head 103 is driven by the actuator 104 through the head arm 102 to scan any position on the substrate 100. Scanning is performed in the manner that the information recording head 103 slides on the substrate 100 and forms inversed magnetic domains on the magnetic recording film formed on the disk substrate. Although one substrate 100 is fixed to the spindle 101 in the figure, the number of disk substrates is not limited particularly to one, but two or more substrates are similarly fixed.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for holding information using a disk-shaped recording medium, and more particularly to a magnetic disk apparatus. 2. Description of the Related Art The components of an information recording apparatus using a disk-shaped recording medium are roughly classified, and a rotating mechanism portion for rotating the recording medium and a head for recording / reproducing information are provided at predetermined positions on the recording medium. It can be classified into a head moving mechanism portion that moves to the position and a circuit portion that processes an electric signal related to recording / reproduction and device control. As one of the conventional techniques for reducing the power consumption of an information processing apparatus, as is known in, for example, Japanese Patent Laid-Open No. 6-259163, a clock signal is supplied only to necessary functional blocks of a circuit portion. There is a method of reducing the power consumption of the circuit. At present, the digital circuit elements of the C-MOS process, which make up most of the circuit, consume very little power in the steady state where the output logic level does not change, but on the contrary, the large power consumption occurs at the moment when the output logic level reverses. Consume. Generally, digital circuits operate in synchronization with the cycle of the clock signal that serves as the reference for operation, so if the clock signals are not supplied to functional blocks that are not necessary for operation and output logic level inversion is suppressed, consumption occurs. It is possible to reduce the power. As a second conventional technique for reducing power consumption, there is a method of controlling the rotation of a recording medium as necessary, as is known in the ANSI x39.2 standard, for example. That is, the rotation of the recording medium is stopped when there is no access request for a predetermined time or longer in response to a command from the outside of the apparatus or a timer in the apparatus. This can reduce the power consumption of the spindle motor that rotates the recording medium. In the first prior art, there is a limit in the functional blocks that can stop the supply of the clock signal, and there is a limit in the power saving of the circuit part. . In addition, it had no effect on the mechanism part and the drive circuit system of the mechanism. In the second conventional technique, when the period until the rotation of the recording medium is stopped is set to be long, the rotation is rarely stopped and the power saving effect is diminished. On the contrary, when the period until the rotation is stopped is set to be short, the rotation frequently stops. When the rotation of the recording medium is stopped, even if the rotation is restarted, the access request cannot be processed until the number of rotations of the recording medium rises and stabilizes at a predetermined number of rotations. If set to, the apparent access performance of the device will deteriorate. In order to solve this problem, the output torque of the spindle motor that rotates the recording medium should be increased, but in this case, the power consumption of the spindle motor at the start of rotation is increased, resulting in an average Power consumption increases, which contradicts the original purpose. Also, the capacity of the power supply that supplies power is governed by the maximum power consumption of the device, so if the average power consumption is low but the peak power consumption is high, secure the power supply capacity according to the peak power consumption. There is a need. Therefore, setting the output torque of the spindle motor to an excessively large value poses a problem in terms of downsizing the power supply unit. For the above reasons, even if the above-mentioned conventional technique is introduced into the information recording apparatus for the purpose of reducing power consumption, the improvement effect is limited. For the purpose of solving the above problems, in an information recording apparatus for holding information on a disk-shaped recording medium, the thickness of the inner peripheral portion and the thickness of the outer peripheral portion of the recording medium are Use different recording media. Alternatively, in an information recording device that holds information on a disk-shaped recording medium, a recording device that has a mechanism for controlling the number of rotations of the recording medium per unit time and the inner peripheral portion and the outer peripheral portion of the recording medium have different thicknesses is recorded. Use medium. Now, the disk substrate 100 shown in FIGS.
Consider a moment of inertia of 200. Inner diameter of disc substrate 2
Ri is an annular plate with an outer diameter of 2Ro and its density is uniform at ρ. In this case, the moment of inertia I with the spindle axis per disk substrate as the rotation axis is
If the disk substrate thickness at the distance r from the rotation axis, that is, the radius r is t (r), then generally I = ∫ {2πdt (r) r ^ 3} dr
It is represented by Here, “^” is an exponentiation operator, and the range of integration is Ri ≦ r ≦ Ro. Therefore, the moment of inertia I200 of the disk substrate 200 in Fig. 2 is t (r)
= to can be calculated as I200 = πρto (Ro ^ 4-Ri ^ 4) / 2. The mechanical strength of the disk substrate should be such that the vibration of the disk substrate surface does not hinder the recording / reproducing operation and can withstand the tensile stress accompanying rotation. Therefore, as shown in FIG. 1, generally with respect to the disk thicknesses t (r1) and t (r2) at the radial positions r1 and r2, r1 ≦
In the case of r2, if the structure of the disk substrate 100 is designed so that to ≧ t (r1) ≧ t (r2), the variable thickness disk substrate
Moment of inertia of 100 I100 is a disk substrate of constant thickness 2
It becomes smaller than the inertia moment I200 of 00. When an object is rotated at an angular acceleration, the torque required for the acceleration is proportional to the moment of inertia of the object and the angular acceleration. Therefore, if the moment of inertia of the recording medium can be reduced, it is necessary to reduce the torque required to accelerate the recording medium to a predetermined rotation speed from a stationary state, or to accelerate to the predetermined rotation speed with the same torque. The time can be shortened, and as a result, the spindle motor can be made smaller and lighter. At the same time, the power consumption of the spindle motor can be reduced. Furthermore, the demand for power capacity can be reduced, and the power unit can be made smaller and lighter.
Secondary effects can be expected. By taking the above means, the moment of inertia of the recording medium can be reduced without impairing the mechanical strength of the recording medium, and the effect of lowering the power consumption and the size and weight of the apparatus as a whole is expected. it can. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described. FIG. 1 is a diagram for explaining an example of the structure of a disk device according to the present invention. The thickness of the disc substrate 100 that holds information varies depending on its radial position, and there is generally a relation of ti≤to between the disc thickness ti of the inner peripheral portion and the disc thickness to of the outer peripheral portion. The disk substrate 100 rotates about the spindle 101, and at the same time the magnetic head 103
Is driven by an actuator 104 via a head arm 102 to scan an arbitrary position on the disk substrate 100. Information is recorded by the magnetic head 103 sliding on the disk substrate 100 to form inverted magnetic domains on a magnetic recording film (not shown) formed on the disk substrate. Further, in FIG. 1, for simplicity, the number of the disc substrates 100 fixed to the spindle 101 is one, but this does not limit the number of disc substrates in particular, and two or more disc substrates may be fixed. The same is true for the case. FIG. 3 is a diagram for explaining an example of the configuration of the device according to the present invention. Main controller 307 is timer 306
Timing result by subtraction operation and external interface 3
The spindle motor 302 is driven through the motor drive circuit 303 while referring to the information from 10
To control the rotation of At the time of recording information, the user data 313 stored in the buffer memory 311 via the external interface 310 is encoded by the encoder 308, and is encoded as encoded data 314 by the magnetic head drive circuit.
It is transmitted to 304. The magnetic head drive circuit 304 drives the magnetic head 104 in accordance with the encoded data 314 and generates a recording magnetic field to generate user data on the disk 300.
Inversion magnetic domains (not shown) corresponding to 313 are formed. At the time of reproducing information, the leakage magnetic field generated from the inverted magnetic domain is converted into an electric signal by the magnetic head 104, and this reproduced signal 31
5 is amplified by the reproduction amplifier 301. The output signal of the reproduction amplifier 301 is further equalized by the waveform equalizer 305, and then input to the binarization circuit 309, and the encoded data 314
Is restored. In addition, the encoded data 304 is the decoder 312
After being decoded by and stored in buffer memory 311
User data 313 is fetched outside the device through the external interface 310 as necessary. FIG. 4 is a diagram for explaining an example of the operation of the device according to the present invention. When the disk device starts to operate by turning on the power or receiving an initialization command from the outside, it spins up the spindle motor 302 and then the timer 30
Set the time to spin down to 6. Next, the main controller 307 checks the access request and, if there is an unprocessed access request, processes the access request and resets the spin down time in the timer 306 to eliminate the unprocessed access request. The above operation is repeated. Once there are no outstanding access requests, the main controller 307 checks the time remaining in the timer 306 and waits again for access requests during the time remaining. When the timer 306 has run out of time, the main controller 307 spins the spindle motor 302.
It goes down and waits in that state until there is an access request again, and when there is an access request, the spindle motor 302 is spun up to return to the first processing. According to the present invention, the moment of inertia of the disk can be reduced as compared with the conventional information recording apparatus using a disk substrate having a uniform thickness, which is necessary at the start of rotation of the recording medium. The torque can be reduced. This makes it possible to reduce the size and weight of the spindle motor, reduce power consumption, and reduce the burden on the power supply. As described above, the size and weight of the device and the power source can be reduced and the power consumption can be reduced, and the cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view illustrating the structure of a disk device according to the present invention. FIG. 2 is a perspective view illustrating the structure of a conventional disk device. FIG. 3 is a block diagram illustrating the configuration of an apparatus according to the present invention. FIG. 4 is a flowchart illustrating the operation of the device according to the present invention. [Explanation of symbols] 100, 200 ... Disk substrate 101 ... Spindle 103 ... Magnetic head 302 ... Spindle motor 303 ... Motor drive circuit 306 ... Timer 307 ... Main controller.

Claims (1)

Claim: What is claimed is: 1. An information recording apparatus for holding information on a disk-shaped recording medium, wherein the recording medium has different inner and outer peripheral thicknesses. 2. An information recording apparatus for holding information on a disk-shaped recording medium, comprising a mechanism for controlling the number of rotations of the recording medium per unit time, the thickness of which changes depending on the distance from the rotation axis. An information recording apparatus using a recording medium. 4. An information recording apparatus for holding information on a disk-shaped recording medium, comprising a mechanism for controlling the number of rotations of the recording medium per unit time, An information recording apparatus using the above recording medium, the thickness of which decreases as the distance from the axis increases.