WO1997019449A1 - Head cleaning by loading heads at low speed - Google Patents
Head cleaning by loading heads at low speed Download PDFInfo
- Publication number
- WO1997019449A1 WO1997019449A1 PCT/US1996/017978 US9617978W WO9719449A1 WO 1997019449 A1 WO1997019449 A1 WO 1997019449A1 US 9617978 W US9617978 W US 9617978W WO 9719449 A1 WO9719449 A1 WO 9719449A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- data storage
- storage device
- medium
- head
- device recited
- Prior art date
Links
- 238000004140 cleaning Methods 0.000 title claims abstract description 47
- 238000013500 data storage Methods 0.000 claims description 38
- 239000003550 marker Substances 0.000 claims description 17
- 238000003780 insertion Methods 0.000 claims description 3
- 230000037431 insertion Effects 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 claims 2
- 230000000977 initiatory effect Effects 0.000 claims 2
- 230000000881 depressing effect Effects 0.000 abstract 1
- 239000000725 suspension Substances 0.000 description 15
- 238000009987 spinning Methods 0.000 description 9
- 230000003287 optical effect Effects 0.000 description 6
- 230000015556 catabolic process Effects 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/60—Fluid-dynamic spacing of heads from record-carriers
- G11B5/6005—Specially adapted for spacing from a rotating disc using a fluid cushion
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
- G11B23/50—Reconditioning of record carriers; Cleaning of record carriers ; Carrying-off electrostatic charges
- G11B23/505—Reconditioning of record carriers; Cleaning of record carriers ; Carrying-off electrostatic charges of disk carriers
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/41—Cleaning of heads
Definitions
- the present invention relates to a data storage device having read/write heads for accessing information on a storage medium and, more particularly, to cleaning the heads by loading them onto the disk surface which is rotating at a low speed below that at which the heads have pseudo contact.
- the normal operating speed for the spinning disk is about 5600 ⁇ m. At about 1900 ⁇ m, the heads start to lift away from the disk surface. The head/disk interface pressure decreases as the speed increases.
- Data storage devices and in particular, data storage devices of the type that accept a removable cartridge containing a disk-shaped storage medium, usually employ either a linear actuator mechanism or a rotary arm actuator mechanism for positioning the read/write heads of the disk drive over successive tracks of the disk-shaped storage medium.
- the linear or rotary arm actuators are moved to a retracted, or parked position when the disk drive is not in use. In such a retracted position, the read/ write heads of the disk drive are removed off and away from the surface(s) of the storage medium in order to prevent damage to the head(s) and storage medium.
- the read/write heads In order to resume use of the disk drive, the read/write heads must once again be loaded onto the surface(s) of the storage medium so that the data transfer can begin. It is important that the head loading operations can be carried out in a controlled manner to prevent damage to the read/write heads.
- head cleaning is accomplished by rotating the disk at low speeds, below the operating rotational speed of the disk. At low speed, increased force between the head and disk is obtained. This cleans the heads.
- the heads are routinely cleaned by loading them onto a slowly spinning data storage disk. As soon as the disk is detected to be spinning, the heads are loaded onto the disk. The disk speed is in the range of 400 ⁇ m, well below the take-off speed. This causes intermittent contact between the head surface and the disk causing abrasion which keeps the head surface clean. In accordance with another aspect of the invention, a more thorough cleaning operation is started manually.
- the eject button on the front of the disk drive is pressed by the operator for longer than a specified period, for example, five seconds. This causes the disk drive to enter a cleaning mode.
- the LED indicator on the front of the disk drive flashes. This signals the operator to insert a cleaning cartridge.
- the cartridge contains disks which are mildly abrasive to the heads.
- the cleaning cartridge is detected by the disk drive by the absence of a retroreflective marker which normally identifies the cartridge as one having information recorded thereon. For example, cartridges which have retroreflective markers thereon are suitable for use with the disk drive. In a cleaning mode, if the cartridge does not have such a marker, the heads are loaded by the disk drive while the disk is spinning at a low speed.
- a low frequency is applied to the voice coil of the actuator to move the heads in a rapid radial motion on the disk surface.
- the disk is spun up to operating speed and then the low frequency is turned off.
- This cleaning cycle is repeated a number of times, for example, five times and then the cleaning cartridge is ejected.
- Figure 1 is a flowchart depicting operation of the control systems in the performance of cleaning
- Figure 2 is a perspective view of a data storage device, or disk drive, in which the present invention may be employed;
- Figure 2A is a perspective view of a portion of the disk drive of Figure 2 showing the mounting of an optical sensor and a gray scale pattern to produce a signal representing the position and velocity of the actuator;
- Figure 2B shows the cartridge;
- Figure 3 is a block diagram of control systems for controlling the position and velocity of the actuator, for controlling capstan speed and for controlling other operations in the cleaning cycle;
- Figure 4 shows various positions of the suspension arms of the actuator during a head loading operation
- Figure 5 is a flowchart illustrating a method of controlling the velocity of the actuator of Figure 1 during the head loading operation
- Figure 6 is a flowchart depicting operation of the control systems in a manually initiated cleaning operation.
- Figure 1 is a flow sheet depicting the operation of the actuator control system and the capstan motor control system in performing the routine head cleaning operation of the present invention.
- the microprocessor 82 (Fig. 3) starts the rotation of the disk at a slow speed.
- a determination is made at 11 as to whether the disk is spirining. About 600 ⁇ m is preferred. It is preferred to load the head onto a slowly spinning disk to prevent ringing. With presently used disks, if the head is loaded onto a stationary disk, ringing may cause the head to lock onto the disk.
- the Disk Spinning Signal applied to microprocessor 82 starts the head loading operation as indicated at 12. This loads the heads onto the slowly spinning disk. A determination is made as to whether the head is on the disk as indicated at 13. When this has been accomplished, a "Head On Disk Signal" from microprocessor 82 is applied to microprocessor 82. In response, microprocessor 82 controls spindle motor 29 to spin up to operating speed as indicated at 14. In this manner, the disk is rotated at a low speed with the heads in intermittent contact with the disk. This removes contamination build-up on the head surface thereby preventing head degradation. The take-off velocity is about 1900 ⁇ m. Below that speed, the intermittent contact causes cleaning. Before describing the manually initiated head cleaning operation, the disk drive and its control systems will be described.
- the disk drive 20 comprises a chassis 21 on which a number of disk drive components are mounted.
- a front panel 24 of the disk drive 20 has a substantially horizontal opening 22 for receiving a removable disk cartridge.
- An LED 27 indicates status of the drive.
- An eject button 26 is provided on the front panel for ejecting a disk cartridge from the disk drive 20.
- a spindle motor 29 is mounted on the chassis 21 to provide a means for rotating the storage media within a disk cartridge.
- An actuator arm 32 which forms part of a rotary arm voice coil actuator, is pivotally mounted to the drive chassis 21 at 38.
- the actuator arm 32 has a plurality of suspension arms 34 at its distal end that each carry a respective read/write head 36 for recording and reading information to and from the surfaces of the storage media of a disk cartridge.
- a head loading mechanism 35 facilitates loading of the magnetic heads onto the storage media.
- the head loading mechanism comprises a pair of load ramp structures 46, 48 upon which the suspension arms 34 of the actuator arm 32 ride during head loading/unloading operations. Further details concerning a head loading mechanism of the type shown at 35 can be found in co-pending, commonly assigned, U.S. Patent Application No. 08/438,254, entitled “Head Loading Mechanism for a Disk Drive, " filed May 10, 1995 (Attorney's Docket No. IOM-8781), which is inco ⁇ orated herein by reference in its entirety.
- Figure 2A is a perspective view of a portion of the disk drive 20 of Figure 2, illustrating the mounting of an optical sensor 54 and gray-scale pattern 52.
- Gray-scale pattern 52 is attached to the lower surface of the voice coil 42.
- the voice coil 42 is mounted to a forked member at the end of the actuator arm 32.
- the optical sensor 54 is rigidly mounted to a surface of the disk drive 20 below the voice coil 42.
- An upper surface of the optical sensor 54 is disposed in facing relation to the gray-scale pattern 52.
- Figure 2B is a perspective view of a disk cartridge 10 that may be used with the removable cartridge disk drive 20 of Figure 2.
- the disk cartridge 10 comprises an outer casing consisting of upper and lower shells 10a, 10b, respectively.
- the disk cartridge 10 contains two disk-shaped mediums 60, 62 that are attached, in stacked relation, to a hub assembly rotatably mounted within the outer casing.
- the cartridge contains cleaning disks.
- the cleaning medium is mildly abrasive to the head.
- a retroreflective marker 11 normally identifies the cartridge as being the correct cartridge for the drive. See “Retroreflective Marker For Data Storage Cartridges, " Serial No. 08/388,242 filed February 14, 1995 (Attorney's Docket No. IOM-8779), which is inco ⁇ orated herein by reference. In accordance with the present invention, the absence of a retroreflective marker identifies the cartridge as being a cleaning cartridge.
- a door 12 on the casing provides access to the recording disks by the read/write heads of a disk drive.
- the actuator arm 32 will rotate counter-clockwise (as viewed in Fig. 2) causing the suspension arms 34 of the actuator to move off the load ramp structures 46, 48, thereby loading the read/write heads 36 onto the disk surfaces within the cartridge 10.
- Figure 3 is a block diagram of closed-loop control systems for control of the actuator and spindle motor during the cleaning cycle.
- the depression of the eject button 26 is detected by microprocessor 82.
- microprocessor 82 intermittently flashes the LED 27 and a cleaning cycle is entered.
- the spindle motor 29 has a control system which includes power amplifier
- Marker detection circuitry 67 detects whether a retroreflective marker 11 is present on the cartridge.
- the marker detection circuitry is fully disclosed in
- the actuator control system comprises the low-pass filter 78 and microprocessor 82.
- the low-pass filter 78 conditions the output of the optical sensor 54 for input to the integrated analog-to-digital converter 84 of the microprocessor 82.
- the position signal is sampled at a predetermined rate and then processed in accordance with a selected velocity control algorithm implemented by the microprocessor 82.
- the microprocessor 82 outputs a control signal, which in the present embodiment may take the form of a series of discrete pulses, to a pulse-width modulation digital-to-analog converter (PWMDAC) 88 via line 86.
- PWMDAC pulse-width modulation digital-to-analog converter
- the PWMDAC 88 converts the pulses of the control signal into an analog control signal and provides the analog control signal to an amplifier 92 via line 90.
- the amplified control signal drives the voice-coil motor of the disk drive via line
- a low-frequency source 89 When the heads are loaded onto the cleaning disk, a low-frequency source 89 is turned on by microprocessor 82. Low-frequency source 89 causes the heads to vibrate in a radial direction at a frequency of about 175 to 200 hertz.
- Figure 4 illustrates various positions of the suspension arms 34 of the actuator arm 32 as they move over the surface of the load ramp structures 46, 48 during a head loading operation. As shown, the suspension arms move along the load ramp structures 46, 48 from “Position 1 ", through “Position 2" to "Position 3". At “Position 3", the suspension arms 34 begin to move down the respective ramped surfaces of the load ramp structures 46, 48.
- the read/write heads 36 (not shown) at the distal ends of the respective suspension arms 34 move toward the respective surfaces of the storage media 60 and 62.
- the suspension arms 34 reach "Position 4", the read/write heads 36 are fully loaded onto the surfaces of the media 60, 62.
- the term "loading" means to bring the read/write heads of the disk drive into normal operating position with respect to the surfaces of the storage media.
- FIG. 5 illustrates the operation of the actuator control system of Figure 3 during the head loading sequence illustrated in Figure 4.
- microprocessor control passes to step 64 where the microprocessor samples the position signal received from the optical sensor 54 to determine the position of the actuator arm, and hence, the suspension arms 34. If the suspension arms are determined to be between "Position 1 " and "Position 2", control passes to step 66 where the microprocessor 82 begins processing the incoming samples of the position signal in accordance with a first velocity control algorithm.
- the first velocity control algorithm is described in greater detail in the aforementioned application (IOM-8782), referred to therein as the "initial push control. "
- step 72 the microprocessor initiates acquisition of the servo track information on the surfaces of the media 60, 62.
- the operation of the disk drive in performing a manually initiated, periodic head cleaning operation of the present invention is depicted in Figure 6.
- Microprocessor 82 detects whether the eject button 26 ( Figure 2) has been held for more than 5 seconds as indicated at 101 in Figure 1. If the eject button has been held for more than 5 seconds, the LED 27 is caused to flash intermittently, indicated by the step 102 in Figure 1.
- Cartridge insertion is detected as indicated at 103. If a cartridge has been inserted, a determination is made as to whether the cartridge has a retroreflective marker. This determination is indicated at 104 in Figure 1. If the cartridge has a retroreflective marker, it is ejected as indicated at 105. Then, the same head cleaning operation of Fig. 1 is performed. The disks are rotated as indicated at 10 and a determination is made as to whether the disks are spinning as indicated at 11. At very low speeds, the heads are loaded onto the disk with a high force between the heads and the disks. As indicated at 12, the heads are loaded. A determination is made as to whether the heads are on the disk, as indicated at 13.
- the heads are moved to the ID, the extreme inner most usable diameter of the disk, indicated by the step 106.
- the low frequency source 89 is energized to induce a low frequency motion of the heads as they engage the disks.
- the performance of this step is indicated at 108.
- the disks are spun up to operating speed as indicated at 14. As the speed increases, the force decreases. In the disk drive under consideration, speeds at about 600 ⁇ m apply enough force for cleaning.
- the disks are spun up to a speed of about 5600 ⁇ m which is the speed for reading and writing data.
- the high frequency source 89 is turned off as indicated by the step 110.
- the spindle motor is turned off to bring the disks down to zero ⁇ m as indicated at 111.
- This head cleaning cycle is repeated five times as indicated at 112.
- the cleaning cartridge is ejected as indicated at 113.
- the head may be loaded with the disk stationary if the disk surface is appropriate.
- the disk is rotated at a low speed to clean the heads.
- the head may be loaded at any speed below take-off speed.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP96940346A EP0862779A4 (en) | 1995-11-20 | 1996-11-06 | Head cleaning by loading heads at low speed |
CA 2238031 CA2238031A1 (en) | 1995-11-20 | 1996-11-06 | Head cleaning by loading heads at low speed |
JP09519763A JP2000510635A (en) | 1995-11-20 | 1996-11-06 | Head cleaning performed by loading the head at low speed |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US56086995A | 1995-11-20 | 1995-11-20 | |
US08/560,869 | 1995-11-20 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1997019449A1 true WO1997019449A1 (en) | 1997-05-29 |
WO1997019449A9 WO1997019449A9 (en) | 1997-07-24 |
Family
ID=24239701
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1996/017978 WO1997019449A1 (en) | 1995-11-20 | 1996-11-06 | Head cleaning by loading heads at low speed |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0862779A4 (en) |
JP (1) | JP2000510635A (en) |
WO (1) | WO1997019449A1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998044504A1 (en) * | 1997-04-03 | 1998-10-08 | Iomega Corporation | Thin retroreflective marker for data storage cartridge |
US5992011A (en) * | 1997-10-29 | 1999-11-30 | Iomega Corporation | Method of assembling a baffle to a detector for detecting a retroreflective marker |
US6067214A (en) * | 1995-02-14 | 2000-05-23 | Iomega Corporation | Data cartridge marker for foreign object detection |
WO2000067252A1 (en) * | 1999-05-04 | 2000-11-09 | Terastor Corporation | Optical storage system with head cleaning mechanism |
US6292323B1 (en) * | 1998-01-12 | 2001-09-18 | International Business Machines Corporation | Method and apparatus for removing accumulated particles on a head in an information recording and reproducing apparatus |
EP1150278A1 (en) * | 1999-11-25 | 2001-10-31 | Matsushita Electric Industrial Co., Ltd. | Cleaning disc, magneto-optical disc apparatus and recording/reproducing apparatus |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009230797A (en) * | 2008-03-21 | 2009-10-08 | Fujitsu Ltd | Cleaning system, disk drive, and cleaner |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4065798A (en) * | 1975-08-26 | 1977-12-27 | Fuji Photo Film Co., Ltd. | Cleaning cartridge |
US4291353A (en) * | 1979-06-04 | 1981-09-22 | Texas Instruments Incorporated | System and method for cleaning a magnetic head transducer |
US4384311A (en) * | 1981-10-13 | 1983-05-17 | Dma Systems Corporation | Method for cleaning the disc surface and the head support structure in a magnetic disc drive |
US4594617A (en) * | 1982-08-11 | 1986-06-10 | Canon Kabushiki Kaisha | Method and apparatus for cleaning a recording and/or reproducing head |
JPS62162217A (en) * | 1986-01-10 | 1987-07-18 | Nec Corp | Head cleaning system |
US5315454A (en) * | 1991-02-27 | 1994-05-24 | Matsushita Electric Industrial Co., Ltd. | Loading method of magnetic head and magnetic disc apparatus |
US5384675A (en) * | 1993-09-08 | 1995-01-24 | International Business Machines Corporation | Disk drive with controlled actuator oscillation for release of head carriers |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57200971A (en) * | 1981-06-01 | 1982-12-09 | Hitachi Ltd | Magnetic disk storage device |
-
1996
- 1996-11-06 WO PCT/US1996/017978 patent/WO1997019449A1/en not_active Application Discontinuation
- 1996-11-06 EP EP96940346A patent/EP0862779A4/en not_active Withdrawn
- 1996-11-06 JP JP09519763A patent/JP2000510635A/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4065798A (en) * | 1975-08-26 | 1977-12-27 | Fuji Photo Film Co., Ltd. | Cleaning cartridge |
US4291353A (en) * | 1979-06-04 | 1981-09-22 | Texas Instruments Incorporated | System and method for cleaning a magnetic head transducer |
US4384311A (en) * | 1981-10-13 | 1983-05-17 | Dma Systems Corporation | Method for cleaning the disc surface and the head support structure in a magnetic disc drive |
US4594617A (en) * | 1982-08-11 | 1986-06-10 | Canon Kabushiki Kaisha | Method and apparatus for cleaning a recording and/or reproducing head |
JPS62162217A (en) * | 1986-01-10 | 1987-07-18 | Nec Corp | Head cleaning system |
US5315454A (en) * | 1991-02-27 | 1994-05-24 | Matsushita Electric Industrial Co., Ltd. | Loading method of magnetic head and magnetic disc apparatus |
US5384675A (en) * | 1993-09-08 | 1995-01-24 | International Business Machines Corporation | Disk drive with controlled actuator oscillation for release of head carriers |
Non-Patent Citations (1)
Title |
---|
See also references of EP0862779A4 * |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5986838A (en) * | 1995-02-14 | 1999-11-16 | Iomega Corporation | Thin retroreflective marker for data storage cartridge |
US6067214A (en) * | 1995-02-14 | 2000-05-23 | Iomega Corporation | Data cartridge marker for foreign object detection |
US6292319B1 (en) | 1995-02-14 | 2001-09-18 | Iomega Corporation | Thin retroreflective marker for identifying an object |
WO1998044504A1 (en) * | 1997-04-03 | 1998-10-08 | Iomega Corporation | Thin retroreflective marker for data storage cartridge |
US5992011A (en) * | 1997-10-29 | 1999-11-30 | Iomega Corporation | Method of assembling a baffle to a detector for detecting a retroreflective marker |
US6292323B1 (en) * | 1998-01-12 | 2001-09-18 | International Business Machines Corporation | Method and apparatus for removing accumulated particles on a head in an information recording and reproducing apparatus |
WO2000067252A1 (en) * | 1999-05-04 | 2000-11-09 | Terastor Corporation | Optical storage system with head cleaning mechanism |
US6307832B1 (en) | 1999-05-04 | 2001-10-23 | Terastor Corporation | Optical storage system with head cleaning mechanism based on a position-controllable optical interfacing surface in an optical head |
US6577575B2 (en) | 1999-05-04 | 2003-06-10 | Terastor Corporation | Head cleaning in Optical disk drives |
EP1150278A1 (en) * | 1999-11-25 | 2001-10-31 | Matsushita Electric Industrial Co., Ltd. | Cleaning disc, magneto-optical disc apparatus and recording/reproducing apparatus |
EP1150278A4 (en) * | 1999-11-25 | 2006-11-22 | Matsushita Electric Ind Co Ltd | Cleaning disc, magneto-optical disc apparatus and recording/reproducing apparatus |
Also Published As
Publication number | Publication date |
---|---|
JP2000510635A (en) | 2000-08-15 |
EP0862779A1 (en) | 1998-09-09 |
EP0862779A4 (en) | 2000-02-23 |
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