JP2003045136A - Recording medium drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to a recording medium and a head by avoiding the contact of the head with the recording medium caused by vibration from the outside. SOLUTION: This recording medium drive unit is provided with a head advancement or retraction drive part 11 to displace the head 4 to an advance position and a retraction position on the recording medium 1, and a vibration detecting sensor to output a signal corresponding to the vibration applied from the outside. When the level of the vibration detected by the vibration detecting sensor is judged to be a strong level exceeding a reference value, the drive part 11 retracts the head 4 to the retraction position separated from the recording medium 1. Accordingly, the contact of the recording medium 1 with the head 4 is avoided when the vibration of the strong level is exerted from the outside, thereby prevents the damage caused by the contact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium drive device capable of recording and reproducing digital data or only reproducing it.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Laid-Open Nos. 11-86507 and 6-
As described in Japanese Patent Laid-Open No. 60607 and Japanese Patent Laid-Open No. 4-111280, a drum-type recording medium and a head facing the recording medium are provided, and recording and reproduction of information on the recording medium or reproduction is performed. There is known a recording medium driving device which is designed to do only this. Among the above publications, JP-A-11-865
The example described in Japanese Patent Publication No. 07 has a plurality of recording and reading means corresponding to each track of the recording medium as a head. The examples disclosed in JP-A-6-60607 and JP-A-4-111280 include one head (including an optical pickup) that is linearly driven in the track direction of the recording medium.

Further, as described in Japanese Patent Application Laid-Open No. 8-115579, a recording medium driving device having a disk type recording medium and a head which is reciprocally driven in the track direction of the recording medium ( There is a rotary storage device). In this publication, a head positioning error occurs when a large vibration or shock is applied from the outside, and vibration or shock is detected in order to prevent data recording failure, reproduction failure, data destruction, or the like that occurs due to this. When the characteristics of the translational acceleration detecting means are set to substantially the same frequency characteristics as the acceleration disturbance characteristics of the head positioning system, and when vibration exceeding the reference value is applied,
It is described that recording / reproducing operation control, head retracting operation control, data protection operation, device protection operation, and the like are performed.

[0004]

The feature of the invention described in Japanese Patent Application Laid-Open No. 8-115579, which deals with an external shock, is that the characteristics of the translational acceleration detecting means for detecting vibration are the same as the acceleration disturbance characteristics of the head positioning system. Since the frequency characteristics are substantially the same, no specific means for retracting the head when vibration exceeding a reference value is applied is not described. If the strong level vibration continues, the head repeatedly contacts the recording medium, which causes a problem of damaging the recording medium and the head.

An object of the present invention is to prevent the head from coming into contact with the recording medium due to external vibration and prevent damage to the recording medium and the head.

[0006]

The invention according to claim 1 is
From the recording medium, a recording medium driving unit that rotationally drives the recording medium, a head that records or reproduces data on the recording medium, an advance position for recording or reproducing on the recording medium, and the recording medium. A head advancing / retreating drive unit that displaces the head to a retracted position for retracting, a vibration detection sensor that outputs a signal corresponding to vibration applied from the outside, and a vibration level output by the vibration detection sensor that exceeds a reference value. Vibration determination means for determining whether or not it is a level,
The operation of the head advancing / retreating drive unit is such that the head is advanced to the advance position when the level of vibration applied from the outside is a reference value or less, and the head is retracted to the retreat position when the level is strong. Head advancing / retreating control means for controlling.

Here, at the retracted position of the head with respect to the recording medium, the separation distance from the recording medium is 0.1 μm or more and 5000 or more.
It is desirable that the position is less than μm (the optimum value is 100 μm).

The recording medium includes a drum type recording medium and a disc type recording medium.

Therefore, when a strong vibration is applied from the outside, the head can be retracted from the recording medium to avoid the state where both are in contact with each other.

According to a second aspect of the present invention, in the first aspect of the invention, the head advancing / retreating drive unit displaces the head between the advanced position and the retracted position by the displacement operation of the piezoelectric substance.

Therefore, by using a piezoelectric material having a high responsiveness, the head can be quickly retracted from the recording medium.

According to a third aspect of the present invention, in the first aspect of the invention, the head advancing / retreating drive unit displaces the head between the advance position and the retreat position by a displacement operation of an actuator.

Therefore, the head can be retracted to a retracted position far from the recording medium by a large displacement operation of the actuator.

According to a fourth aspect of the present invention, a head advancing / retreating drive unit that displaces the head between the advance position and the retreat position by a displacement operation of a piezoelectric substance, and the head moves to the advance position by an actuator displacement operation. A head advancing / retreating drive unit that is displaced to the retracted position is also used.

Therefore, the head is quickly retracted from the recording medium by the operation of the piezoelectric material having a high responsiveness.
The head can be retracted to a retracted position far from the recording medium by a large displacement operation of the actuator.

The invention according to claim 5 is the invention according to claims 1 to 4.
In the invention described in any one of 1 to 3, an acceleration sensor is used as the vibration detection sensor.

Therefore, the acceleration sensor can monitor the reciprocating vibration in a specific direction that coincides with the contacting / separating direction of the head with respect to the recording medium, and can recognize the tendency of whether the vibration gradually increases. Along with this, it becomes possible to predict the change in the vibration level (including the influence of resonance) after a lapse of a certain period of time and quickly retract the head.

The present invention as defined in claim 6 is any one of claims 1 to 5.
In any one of the inventions described above, a backup power supply that enables the execution of the head advancing / retreating control unit at the time of power failure is provided.

Therefore, even when vibration exceeding the reference value is applied at the time of power failure, the head can be retracted from the recording medium to avoid the state where both heads come into contact with each other.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention.
Or, it demonstrates based on FIG. FIG. 1 is a plan view schematically showing the structure of a mechanical portion of the recording medium driving device, FIG. 2 is a side view thereof, FIG. 3 is a block diagram schematically showing the electrical structure of the recording medium driving device, and FIG. 4 is a head. It is a flow chart which shows advancing / retreating control processing.

First, the structure of the mechanical portion of the recording medium driving device A will be described with reference to FIGS. In this embodiment, a drum type recording medium 1 is used as the recording medium. The drum-shaped recording medium 1 is rotatably supported by bearings 2 at both ends, and one end is connected to a medium driving motor 3 as a recording medium driving unit.

A magnetic head 4 as a head for recording or reproducing data on the recording medium 1 is provided supported by an arm portion 6 of a head support 5. In the present embodiment, the head moving unit 7 that moves the head support 5 together with the magnetic head 4 in the track direction (axial direction) of the recording medium 1 includes a vibrating rod 8 parallel to the axial direction of the recording medium 1. Although it is formed of linear actuators (ultrasonic transducers) 9 and 10 connected to both ends of the vibrating rod 8, other actuators that reciprocally drive the head support 5 in a linear direction may be used. Since the structure of the head moving unit 7 is publicly known, the driving principle will be briefly described.
By selecting, the direction of the vibration generated in the vibrating rod 8 changes. At this time, the head support 5 moves in the direction opposite to the vibration direction.

Here, a head advancing / retreating drive unit 11 for displacing the magnetic head 4 is provided at an advance position for recording or reproduction on the recording medium 1 and an evacuation position for withdrawing from the recording medium 1. The head advancing / retreating drive unit 11 in the present embodiment includes an elastically bendable arm portion 6 of the head support body 5, a piezoelectric element 12 as a piezoelectric substance held by the arm portion 6, and the piezoelectric element 12. It is composed of a piezoelectric element drive circuit (described later) that drives the element 12.
The piezoelectric element 12 bends and bends the arm portion 6 by the expansion and contraction operation by applying a voltage, so that the magnetic head 4 is retracted from the recording medium 1 (the position where the magnetic head 4 is shown by a solid line in FIG. 2) and the retracted position. The magnetic head 4 is displaced to a position (the position shown in phantom in FIG. 2). The retracted position is preferably set such that the separation distance of the magnetic head 4 from the recording medium 1 is 0.1 μm or more and less than 5000 μm, and in the present embodiment, the optimum value is 100 μm.

Next, referring to FIG. 3, a recording medium driving device A
The electrical configuration of will be schematically described. A ROM 13 in which fixed data such as a program is written, a CPU 14 that monitors the operation of each unit and executes the program, and a RAM 15 that saves variable data such as work data in an updatable manner are connected by a system bus 16. An interface 17 connected to an external circuit (not shown), a buffer memory 18 for storing data transmitted from the outside,
Medium drive motor drive circuit 1 for driving the medium drive motor 3
9, a linear actuator drive circuit 20 that drives the linear actuators 9 and 10, a head signal data controller 21 that controls the magnetic head 4, an acceleration sensor 22 as a vibration detection sensor, a piezoelectric element drive circuit 23 that drives the piezoelectric element 12, and a backup. Power supply 31 is CPU1
4 is connected. In this embodiment, the acceleration sensor 22 is MA-3-04Aa manufactured by Microstone Co., Ltd.
Type is used. The acceleration sensor 22 is mounted on a device frame (not shown) of the recording medium driving device A or the like.

In such a recording medium driving apparatus A, the recording medium 1 is rotated by the medium driving motor 3, and the head moving unit 7 moves the head support 5 together with the magnetic head 4 in the track direction (arrow direction in FIG. 1). In the process, the data transferred from the external circuit to the buffer memory 18 is transferred to the magnetic head 4 under the control of the head signal data controller 21.
The data is written in the recording medium 1 by outputting from. Of course, the data written in the recording medium 1 can be read by the magnetic head 4.

Here, the output of the acceleration sensor 22 is compared by the CPU 14 in a constant cycle to determine whether it is a strong level vibration exceeding the reference value or a weak level vibration below the reference value. The magnetic head 4 is advanced to the above-mentioned advance position, and in the case of a strong level, the magnetic head 4
Is retracted to a retracted position (function as a head advancing / retreating control unit). Hereinafter, the forward / backward control process of the magnetic head 4 will be described with reference to the flowchart shown in FIG.

When it is determined that the output of the acceleration sensor 22 is a strong level vibration exceeding the reference value (Y in S1),
Next, it is determined whether or not data recording or reproduction processing is being executed (S2). When it is determined that the process is being executed (Y in S2), the task is interrupted (S3), and when it is determined that an error has occurred when the task is interrupted (S3).
4), an error is displayed on a display (not shown) (S
5). When the determinations in steps S2 and S4 are denied (S
2 N, S4 N) moves to step S6. In step S6, a process of retracting the magnetic head 4 is performed. Specifically, from the piezoelectric element drive circuit 23 to the piezoelectric element 12
Voltage is applied to the arm portion 6 as the piezoelectric element 12 is deformed.
The magnetic head 4 is retracted from the recording medium 1 by flexing.

After that, it is determined whether or not the vibration exceeding the reference value continues in a constant cycle (S7). If it is determined that the vibration is below the reference value (N in S7), the magnetic field is determined. A process for moving the head 4 forward is performed. Specifically, the application of voltage to the piezoelectric element 12 is stopped, and the magnetic head 4 is moved to the recording medium 1 by the restoring action of the elasticity of the arm portion 6 itself.
(S8), and the task interruption performed in step S3 in order to continue the recording or reproducing process is released (S9). At this time, since the error display state continues in step S5, the operator processes the error according to the manual.
When 14 determines that the error processing has been executed (Y of S10), the task for recording or reproduction is re-executed (S11).

In the flowchart shown in FIG. 4, steps S1 and S7 realize a vibration judging means, and step S1
6 and S8 realize head advancing / retreating control means.

Here, since the delay time from the moment when the external vibration is applied to the apparatus frame to the time when the vibration is transmitted to the magnetic head 4 is predicted to be on the order of ten and several ms, the performance of the acceleration sensor 22 is that the external vibration By setting the detection time from the moment when is applied to the device frame until the acceleration sensor 22 detects the vibration to several μm,
The vibration level is detected before the vibration applied to the device frame from the outside is transmitted to the magnetic head 4.
Can be saved from the recording medium 1. Therefore, contact between the recording medium 1 and the magnetic head 4 can be avoided, and damage to both can be prevented. Further, in the present embodiment, since the magnetic head 4 is retracted from the recording medium 1 by using the piezoelectric element 12 having a fast response, it is possible to allow a margin for the time for retracting the magnetic head 4 with respect to the delay time.

Further, by monitoring the output of the acceleration sensor 22, it is possible to recognize whether or not the reciprocating vibration in a specific direction that coincides with the contacting / separating direction of the magnetic head 4 with respect to the recording medium 1 gradually increases. Accordingly, it is also possible to predict the change in the vibration level (including the influence of resonance) after a lapse of a certain period of time and perform the control for promptly retracting the magnetic head 4.

Further, in the present embodiment, since the backup power supply 31 is provided for enabling the head advance / retreat control means (steps S6 and S8 in the flowchart shown in FIG. 4) at the time of power failure, vibration exceeding the reference value at the time of power failure is provided. Even when a magnetic field is applied, the magnetic head 4 can be retracted from the recording medium 1 to avoid a state in which the both are in contact.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted. FIG. 5 is a plan view schematically showing the structure of the mechanical portion of the recording medium driving device, FIG. 6 is a side view thereof, and FIG. 7 is a block diagram schematically showing the electrical structure of the recording medium driving device.

The recording medium driving device B of this embodiment is different from the recording medium driving device A of the above-mentioned embodiment only in the configuration of the head advancing / retreating drive section 24. The head advancing / retreating control process is the same as the flowchart in FIG. The head advancing / retreating drive unit 24 in the present embodiment includes a cam 25 installed in parallel with the vibrating rod 8 so as to support the arm unit 6 over the moving range of the magnetic head 4, a cam drive motor 26 as an actuator, and the cam 25. And a cam drive circuit 27 (see FIG. 7) for driving. Shaft 28 of cam 25
Is rotatably supported by a bearing 29, and the other end is connected to a cam drive motor 26 via a joint 30. The cam 25 may be an eccentric cam as long as it has a protrusion on a part of its outer periphery that presses the arm 6 in a direction of separating it from the recording medium 1.

In such a configuration, the head retreat processing for retracting the magnetic head 4 that has advanced to the advance position shown by the solid line in FIG. 6 to the retracted position shown by the phantom line, and the magnetic head 4 is advanced from the retracted position to the advance position. The processing will be described. In the head retreat processing in step S6 shown in the flowchart of FIG. 4, the cam drive circuit 27 drives the cam drive motor 26 by a predetermined number of steps, and the cam 2
In this process, the arm 5 is pushed up by the cam 25 by rotating the magnetic head 5 by a certain angle to retract the magnetic head 4 to the retracted position. Step S in the flowchart shown in FIG.
In the process of advancing the head in 8, the cam drive circuit 27 drives the cam drive motor 26 by a predetermined number of steps to rotate the cam 25 by a predetermined angle to release the arm portion 6, thereby causing the arm portion 6 to elastically move. This is a process for returning the magnetic head 4 to the advanced position by moving the magnetic head 4 to the advanced position.

In this case, the cam 25 is driven by the cam drive motor 26.
With the mechanism for rotating the magnetic head 4, it is easy to increase the amount of displacement of the magnetic head 4, and the magnetic head 4 can be retracted to a retracted position far from the recording medium 1. Therefore, even if the recording medium 1 and the magnetic head 4 are subjected to vibrations with large amplitude,
It is possible to avoid contact with.

Furthermore, FIG. 8 shows a third embodiment of the present invention.
It will be described based on. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted. FIG. 8 is a plan view schematically showing the structure of the mechanical portion of the recording medium driving device. The recording medium driving device C in the present embodiment includes both the head advancing / retreating drive unit 11 in the first embodiment and the head advancing / retreating drive unit 24 in the second embodiment.

In such a structure, the head retracting process in step S6 in FIG. 4 causes the magnetic head 4 to be quickly retracted from the recording medium 1 by the operation of the piezoelectric element 12 having a high responsiveness, and the cam drive motor 26 The magnetic head 4 can be retracted to a retracted position far from the recording medium 1 by a large displacement operation of the cam 25 driven by.

[0039]

According to the first aspect of the present invention, the head advancing / retreating drive section for displacing the head between the advancing position and the retreating position with respect to the recording medium, and the vibration detecting sensor for outputting a signal corresponding to the vibration applied from the outside. And a vibration judging means for judging whether or not the level of vibration output by this vibration detecting sensor is a strong level exceeding a reference value, and when the vibration applied from the outside is a strong level, the head is moved to the retracted position. Since the head is retracted, it is possible to retract the head from the recording medium when strong vibration is applied from the outside, avoid contact between the two, and prevent damage due to the contact.

According to the invention of claim 2, in the invention of claim 1, the head advancing / retreating drive section displaces the head between the advance position and the retreat position by the displacement operation of the piezoelectric substance. The head can be quickly retracted from the recording medium by the rapid displacement operation of the piezoelectric substance.

According to the invention of claim 3, in the invention of claim 1, the head advancing / retreating drive unit displaces the head between the advance position and the retreat position by the displacement operation of the actuator. Therefore, a large displacement operation of the actuator is performed. The head can be retracted to a retracted position far from the recording medium, and therefore, even if the recording medium receives a vibration having a large amplitude, it is possible to avoid contact between the recording medium and the magnetic head.

According to the fourth aspect of the present invention, the head advancing / retreating drive section for displacing the head between the advance position and the retreat position by the displacement operation of the piezoelectric substance, and the head advance and retract position by the displacement operation of the actuator. Since it is also used with a head advancing / retreating drive section for displacing the head, the head is quickly retracted from the recording medium by the action of a piezoelectric material with a fast response, and the head is moved to a retracted position far from the recording medium by a large displacement operation of the actuator. Can be evacuated.

According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, since the vibration detecting sensor uses an acceleration sensor, the acceleration sensor detects the direction of contact and separation of the head with respect to the recording medium. It becomes possible to monitor the reciprocating vibrations in the matching specific direction and recognize the tendency of whether the vibrations gradually increase, and with this change in the vibration level (including the effect of resonance) after a certain period of time elapses. The head can be retracted promptly after the prediction.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, a backup power supply is provided for enabling the head advancing / retreating control means to be executed at the time of power failure. Even when a vibration exceeding the above is applied, the head can be retracted from the recording medium to avoid contact between them and prevent damage due to the contact.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing a configuration of a mechanical section of a recording medium driving device according to a first embodiment of the present invention.

FIG. 2 is a side view thereof.

FIG. 3 is a block diagram schematically showing an electrical configuration of a recording medium driving device.

FIG. 4 is a flowchart showing a head advancing / retreating control process.

FIG. 5 is a plan view schematically showing a configuration of a mechanical portion of a recording medium driving device according to a second embodiment of the present invention.

FIG. 6 is a side view thereof.

FIG. 7 is a block diagram schematically showing an electrical configuration of a recording medium driving device.

FIG. 8 is a plan view schematically showing a configuration of a mechanical section of a recording medium driving device according to a third embodiment of the present invention.

[Explanation of symbols]

1 recording medium 3 Recording medium drive 4 heads 11 Head advance / retreat drive unit 12 Piezoelectric substance 22 Vibration detection sensor 24 Head advance / retreat drive unit 26 actuators S1, S7 Vibration judgment means S6, S8 Head advance / retreat control means

Claims (6)

[Claims] 1. A recording medium, a recording medium driving unit that rotationally drives the recording medium, a head that records or reproduces data on the recording medium, and an advance position for recording or reproducing on the recording medium. And a head advancing / retreating drive unit that displaces the head to a retracted position that retracts from the recording medium, a vibration detection sensor that outputs a signal corresponding to vibration applied from the outside, and a vibration level output by the vibration detection sensor Vibration determination means for determining whether or not the level is a strong level exceeding a reference value, and when the level of vibration applied from the outside is a reference value or less, the head is advanced to the advance position, and when the level is a strong level, the head is advanced. And a head advancing / retreating control means for controlling the operation of the head advancing / retreating drive section so as to retract the head to the retracted position. 2. The recording medium drive device according to claim 1, wherein the head advancing / retreating drive unit displaces the head between the advance position and the retreat position by a displacement operation of a piezoelectric substance. 3. The recording medium drive device according to claim 1, wherein the head advancing / retreating drive unit displaces the head between the advance position and the retreat position by a displacement operation of an actuator. 4. A head advancing / retreating drive unit for displacing the head between the advance position and the retreat position by a displacement operation of a piezoelectric substance, and displacing the head between the advance position and the retreat position by a displacement operation of an actuator. The recording medium drive device according to claim 1, which is used together with a head advancing / retreating drive unit. 5. The recording medium driving device according to claim 1, wherein the vibration detection sensor uses an acceleration sensor. 6. The recording medium drive device according to claim 1, further comprising a backup power supply that enables execution of the head advancing / retreating control unit in the event of a power failure.