KR20040007470A - Multi-phase acceleration of a data storage disc - Google Patents

Abstract

Disc drive with a multi-stage acceleration method is disclosed. The multi-stage acceleration method accelerates the data storage disk of the disk drive from the initial rotational speed to the final rotational speed. When the disc reaches its final rotational speed, a read / write head operable to access data on the disc is moved by the servo control system from the landing zone to the data area on the disc. An air bearing is created between the slider of the read / write head and the disk surface because of the final rotational speed of the rotating disk. The read / write head may also be moved out of the landing zone when the disc reaches an early escape rotational speed. Accordingly, the multi-stage acceleration method continues to accelerate the disc to its final rotational speed to ensure that an air bearing is held between the head and the disc.

Description

MULTI-PHASE ACCELERATION OF A DATA STORAGE DISC}

Current hard disk drives include one or more rigid discs coated with magnetic media and mounted on a spindle hub of a high speed spindle motor. The information is read from and written to each disc on a plurality of concentric tracks by a read / write head mounted on an actuator arm. The outer circumference of each disk is referred to as "outer diameter" (OD) and the center of each disk is referred to as "inner diameter" (ID). The read / write head is said to "fly" over the disk surface as the disk rotates. As the disk rotation speed decreases, the air layer supporting the read / write head over the disk surface gradually disappears, and the head descends toward the disk surface. Contact between the read / write head and the disk surface can damage the magnetic medium and the head. Further, through a phenomenon called "stiction", the read / write head can be "stuck" on the disk surface after landing on the disk surface. Stictions can damage magnetic media, read / write heads, and / or actuator arms when the disc drive system starts rotating the disc to move the read / write head from the disc surface. .

Conventional contact-start-stop (CSS) solutions can be used to solve this problem. In a disc drive system using the CSS interface, the read / write head is placed on a textured landing area, preferably near the disc's ID, as the rotational speed of the disc is reduced and consequently spinning is complete. Landed and parked. Typically, data is not written to the landing zone, so texturing of the landing zone surface minimizes stiction. The read / write head is moved from the landing zone back to the data area on the disc when the rotational speed is increased to cause the head to fly over the disc surface.

To reduce flight height and increase air density, conventional CSS solutions use a padded slider that rises and lands in the laser textured landing area using lower laser bumps. It has been going on. However, the implementation is not without problems. For example, the padded slider solution produces high friction during contact between the slider and the landing zone. Moreover, padded sliders can result in excessive wear of the coating on the disc. Another problem with padded sliders is also related to normal wear and thus to the maintenance of padded slider pads. Excessive wear of both the disk and the pad on the slider can cause premature failure and breakage of the head media interface. Wear of the slider pad can also increase the stickion between the slider and the disk surface.

The present invention relates generally to data storage devices and, more particularly, to a multi-stage acceleration method for rotating a data storage disk in a disk drive. However, the present invention is not limited thereto.

1 is a plan view of a disk drive using a preferred embodiment of the present invention, showing the main internal components.

FIG. 2 is a functional block diagram schematically illustrating the main functional components used to control the disk drive of FIG. 1.

3 is a plan view of a disc, showing schematically the major components on the disc surface according to an embodiment of the invention.

4 is a graph showing a change in friction force when the rotational speed of the disc is increased from the initial speed to the final speed at a constant acceleration.

FIG. 5 is a graph showing the change in rotational speed during the time when the disk of FIG. 4 is accelerated with a constant acceleration between initial speed and final speed.

6 is a graph showing a change in rotational speed during acceleration with multiple accelerators in accordance with one embodiment of the present invention.

FIG. 7 is a graph showing a change in frictional force when the rotational speed of the disk is increased from the initial speed to the final rotational speed with a multi-accelerator according to an embodiment of the present invention, such as the constant acceleration indicated in FIG. 5. .

8 is a flow diagram showing operating characteristics of the multi-stage acceleration method according to an embodiment of the present invention.

9 is a flow diagram illustrating in more detail the operating characteristics shown in FIG. 8 in accordance with an embodiment of the present invention.

FIG. 10 is a flow diagram illustrating operating characteristics of a multi-stage acceleration method using early escape techniques to access tracks on a data storage disk in accordance with an alternative embodiment of the present invention.

In order to solve the problems of the background art, the present invention has been developed. The present invention is a multi-phase acceleration method for rotating a disc in a disc drive. Be more specific, the multi-stage acceleration method is to rotate to its final rotational speed (V _F) from the initial rotational speed (V _i) during a disk a predetermined time (T _F -T _i). The multi-stage acceleration method is applied to the start time (T _i) starting the disk rotation and the final speed (V _F) multiple acceleration stages, multiple acceleration or multi-accelerators (acceleration phase) to set the rotational speed of the disc in a disc do. Initial rotational speed (V _i ), the time at which the disk spins at the initial rotational speed (V _i ) (T _i ), the final rotational speed of the disk (V _F ), and the time at which the disk reaches its final rotational speed (T Predetermined limits and variables, such as _F ), may be set to a predetermined value or range of values, depending on a predetermined number of factors including, but not limited to, the disk drive design and operating specifications.

According to one embodiment, the multi-step acceleration method is used to create and maintain an air bearing between the read / write head and the disk surface when the read / write head approaches a track on the disk surface in response to the read / write instruction. Can be used. Thus, the final rotational speed V _F can be determined as a speed sufficient to hold the air bearing as the read / write head moves across the disk between the inner and outer diameters of the disk. When the disc reaches its final rotational speed V _F , the read / write head can be moved from the landing zone to one or more data zones on the disc. By accelerating the disk with multiple accelerators, friction between the slider and the disk surface can be minimized or eliminated entirely, thereby reducing wear on the landing area surface and the slider.

According to another embodiment, the multiple accelerator method may accelerate the disc with multiple accelerations based on a predetermined time zone between the start time variable _Ti and the last time variable T _F. Thus, the disc can be accelerated with a first acceleration from time T _i to a predetermined time variable T _N , but from time T _N to time T _{F with} a second acceleration. The time T _F is the time at which the rotational speed of the disk reaches a speed sufficient to create and maintain an air bearing between the slider of the head and the surface of the disk when the head moves radially across the disk between the inner and outer diameters. May be the same. Thus, the read / write head can be moved from the landing zone to one or more data zones on the disc at time T _F.

According to another embodiment, the multi-stage acceleration method involves the read / write head exiting the landing zone when the disc rotates at a rotational speed less than the final rotational speed V _F , thereby causing one or more data areas on the disc. Can be used to enter Thus, the read / write head can escape the landing zone when the disc reaches the desired early exit velocity V _D. The desired early escape velocity V _D is a speed sufficient to form an air bearing between the slider and the disk surface when the head is located near the inner diameter, but the desired early escape velocity V _D is determined by When moving towards the outer diameter, it may not be sufficient to hold the air bearing. Thus, the multiple accelerator method may accelerate the disc with one or more accelerations after the head exits the landing zone to maintain the air bearings as the head is moved across the disc toward the outer diameter.

The invention may also be practiced as a computer-readable program storage device that substantially implements an instruction program executable by a computer system to accelerate the data storage disk with multiple accelerations to obtain a final rotational speed of the rotating disk. have.

The above and various other features as well as the advantages unique to the present invention will become apparent upon reading the following detailed description and reviewing the accompanying drawings.

The invention and various embodiments of the invention are described in detail below with reference to the drawings. When referring to the drawings, like structures and components shown are denoted by like reference numerals.

A disk drive 100 made in accordance with a preferred embodiment of the present invention is shown in FIG. The disk drive 100 includes a base 102 on which many components of the disk drive 100 are mounted. The top cover 104, shown partially broken, cooperates with the base 102 to create a sealed interior environment for the disk drive 100 in a conventional manner. The components include a spindle hub 106 (FIG. 2) that rotates the spindle hub 106 and one or more disks 108 attached to the hub 106 at a constant high speed. Although magnetic media disk 108 is used to describe the preferred embodiment of the present invention, the present invention may be practiced using other types of data storage disks. The information is recorded in tracks 306 (FIG. 3) on the disc 108 using the actuator assembly 110 rotating about a bearing shaft assembly 112 located near the disc 108 and from the tracks. Is read. The actuator assembly 110 includes a plurality of actuator arms 114 extending towards the disk 108, with one or more flexures 116 extending from each actuator arm 114. A transducer or read / write head 118 is mounted on the distal attachment of each flexure 116 to fly near the corresponding surface of the associated disk 108 and the transducer or read / write head ( 118 includes an air bearing slide (not shown) that enables transducer or read / write head 118.

Spindle motor 156 is typically de-energized when disk drive 100 is not used for an extended time period. According to one embodiment of the invention, the read / write head 118 is located in the park near the inner diameter (ID) 136 of the disk 108, or in the landing zone 120 when the drive motor 156 is powered off. Can be moved up. Read / write head 118 may be secured over landing area 120 through an actuator latch device (not shown), which is intended for actuator assembly 110 when head 118 is parked. To prevent accidental rotation. The latch device is typically a magnetic latch that magnetically holds the actuator assembly 110 relative to the stationary device. Although the landing zone 120 is shown in FIG. 1 as if located near the inner diameter 136 of the disk 108, the landing zone 120 may also be positioned near the outer diameter OD. Furthermore, landing zone 120 may be located on any portion of disk 108 between outer diameter 138 and inner diameter 136 of disk 108.

The radial position of the head 118 is controlled through the use of a voice coil motor (VCM) 124, where the VCM is typically placed therein as well as the coil 126 attached to the actuator assembly 110. One or more permanent magnets 128 that make up a magnetic field. Controlled current supply to the coil 126 causes magnetic interaction between the permanent magnet 128 and the coil 126 such that the coil 126 moves according to a known Lorentz relationship. As the coil 126 moves, the actuator assembly 110 pivots the bearing shaft assembly 112 and the head 118 moves across the surface of the disk 108.

The flex assembly 130 provides the necessary electrical connection passages to the actuator assembly 110 while allowing the pivotal movement of the actuator assembly 110 during operation. Flexible assembly 130 includes a printed circuit board 132 to which head wires (not shown) are connected; The head wire is routed along the actuator arm 114 and the flexure 116 to the head 118. The printed circuit board 132 typically controls the write current applied to the head 118 during the write operation, and amplifies the read signal generated by the head 118 during the write operation. It includes a circuit. The flexible assembly is mounted at a flexible bracket 134 for communication through a base deck 102 to a disk drive printed circuit board (not shown) mounted on the bottom side of the disk drive 100. Terminated.

Referring now to FIG. 2, shown in FIG. 1, which schematically illustrates a main fuctional circuit resident on a disk drive printed circuit board and used to control the operation of the disk drive 100. A functional block diagram of the disk drive 100 is shown. Disk drive 100 is shown in FIG. 2 as operably connected to host computer 140 on which disk drive 100 is mounted in a conventional manner. A control communication path is provided between the host computer 140 and the disk drive microprocessor 142, which typically includes programming for the microprocessor 142 stored in the microprocessor memory (MEM) 143. Together provide top level communication and control for the disk drive 100. The MEM 143 may include RAM, ROM, and other resident memory sources for the microprocessor 142. The disk 108 is rotated on the spindle hub 106 at a constant high speed by the spindle motor 156 controlled by the spindle control module 148. The spindle control module 148 is a component of an application specific semiconductor (ASIC) 152 that receives instructions about the rotational speed from the microprocessor 142. The microprocessor 142, in communication with the spindle control module 148, determines the rotational speed of the spindle hub 106 to determine the rotational speed of the disk 108 attached thereto. Accordingly, spindle control module 148 receives instructions from microprocessor 142 instructing control module 148 to determine the rotational speed of disk 108.

Spindle control module 148 may be implemented as any type of hardware, such as, for example, digital or analog circuitry, or any type of software, such as, for example, a machine or computer based programming language. Will be described below with analog circuitry for illustration only and not limitation. Accordingly, when the spindle control module 148 is commanded to the desired rotational speed of the disk 108 through communication with the microprocessor 142, the spindle control module 148 turns the winding of the spindle motor 156 (not shown). Supply current to The current supplied to the winding can be generated from a power source, such as a battery source, and the magnitude of the current to be adjusted by the spindle control module 148 so as to command the rotational speed of the disk 108 attached to the spindle hub 106. Can be. Spindle motor 156 may be a "Y" type brushless, three-phase spindle motor with a fixed winding (not shown), such as a field coil, in accordance with one embodiment of the present invention. Accordingly, the spindle control module 148 acts as a power source for the spindle motor 156 by generating current through the windings (not shown) of the motor 156.

The radial position of the head 118 over the rotating disk 108 is controlled by the supply of current to the coil 126 of the VCM 124. Servo control system 150 provides the same control. Like the spindle control module 148, the servo control system 150 is a component of the ASIC 152 and receives commands from the microprocessor 142. When performing a read or write command, microprocessor 142 receives servo information that identifies the position of read / write head 118 on disk 108. Based on the servo information, the microprocessor 142 may require the displacement of the head 118 to seek from the origination track 306 associated with the current head position to the destination track 306. Command the servo control system 150 for. The servo control system 150 then supplies current to the coil 126 of the VCM 124 based on instructions from the microprocessor 142. Controlled current supply to the coil 126 causes magnetic interaction between the permanent magnet 128 (FIG. 1) and the coil 126 such that the coil 126 moves according to the well known Lorentz relations. As the coil 126 moves, the actuator arm 114 and the head 118 relative to the bearing shaft assembly 112 move across the surface of the rotating disk 108.

Data may be transferred to the host computer 140 and the disc by a disk drive interface 144, including a buffer 145 to facilitate high speed data transfer between the host computer 140 and the disk drive 100. Is transferred between drives 100. Thus data to be written to disk 108 is transferred from host computer 140 to buffer 145 and then to read / write channel 146, which encodes the data and serializes the data. It serializes and supplies the necessary write current signal to the head 118. In order to retrieve the data previously stored by the disk drive 100, a read signal is generated by the head 118 and provided to the read / write channel 146. The interface 144 performs recording signal decoding, error detection, and error correction operations. Interface 144 then outputs the retrieved data to buffer 145 for continuous delivery to host computer 140. Such operation of disk drive 100 is known in the art and is disclosed, for example, in US Pat. No. 5,276,662, filed Jan. 4, 1994 by Shaver et al.

When the disk drive is powered off, the microprocessor 142 signals the spindle control module 148 to instruct the spindle control module 148 to disconnect the supply of current to the windings (not shown) of the spindle motor 156. To transmit. The spindle control module 148 opens a circuit such as a relay, a solid state element switch such as a field effect transistor (FET), or the output line of the spindle control module 148 to the spindle motor 156 to open the spindle motor 156 from thereafter. Other switching devices that disconnect the spindle control module 148. While the disk 108 continues spinning because of the rotational inertia in the disk 108, the spindle hub 106, and the disk 108 rotating around the spindle hub 106, immediately begin to lose rotational speed.

When the disk drive is powered off, the servo control system 150 reads / writes the head to prevent the head 118 from contacting the data area or region 304 (FIG. 3) on the surface of the disk 108. Guide 118 to a location away from the data zone 304 of the disk. According to one embodiment of the invention, the location may be a landing area 120 near the ID 136 of the disc. According to another embodiment, the landing zone 120 may be located on the area between the OD 138 and the ID 136 or near the OD 138 of the disk 108.

Regardless of the location of the landing zone 120 on the surface of the disk 108, the landing zone 120 is non-textured, for example a smooth surface, or laser-textured ( laser-textured). Similarly, read / write head 118 may include a textured or non-textured slider (not shown). A particular interface between the disk 108 and the read / write head 118 may be determined based on the slider of the head 118 and the structure of the disk 108, for example textured or non-textured. For example, a LAP interface (Laser Assisted Pad) may be defined as a structure having a slider that is textured or padded with a laser textured disk surface. The laser-texture zone (LZT) interface may be defined as a structure having a laser-textured disk surface and a non-textured or non-padded, slider. The SLIP interface (Slider Landing Integrated Pad) can be defined as a structure with a non-textured disk surface and a textured or padded, slider. According to various embodiments of the present invention, disk drive 100 may include a LAP, LZT or SLIP interface between head 118 and disk 108.

3 to 10 are described below with reference to a single disk 108, with only a single type of interface, the disk drive 100 may include any number of disks 108, Each disk 108 may have any type of interface, such as a SLIP interface, a LAP interface, or an LZT interface. Accordingly, the disk drive 100 may include the first disk 108 having a LAP interface between the disk 108 and the associated read / write head 118, and the disk 108 between the disk 108 and the associated read / write head 118. A third disk 108 having an LZT interface may be included between the second disk 108 having a LAP interface and the read / write head 118 associated with the disk 108. Furthermore, two surfaces of each disk 108 may include a separate type of interface between the read / write heads 118 associated with the surface of the disk 108. Accordingly, the top surface of the disk 108 has a SLIP interface between the read / write head 118 associated with the disk 108 and the bottom surface of the same disk 108 has a read / write head associated with the disk 108. It is possible to have an LZT interface between 118.

3 shows a logical recording structure of a typical disk 108 of the disk drive 100. The disk 108 is divided into several concentric data zones 304 that include an area near the track 306. For example, the magnetic disk 108 of FIG. 3 includes an inner zone 308, an intermediate zone 311, and an outer zone 312. When forming the servo burst sector 314, each disk track 306 is divided into slices called data wedges 316. Burst sector 314 contains data for maintaining the exact position of disk head 118 and is located at a predetermined location along disk 108. As the disk 108 rotates, the data head 118 reads servo information including an address in the servo burst 314 and sends the servo information back to the servo control system 150. The servo control system 150 checks whether the address of the servo information read from the burst sector 314 matches the desired head position. If the address does not match the desired head position, the actuator arm 114 is adjusted until the head 118 is moved to the correct track position.

Each track 306 includes a separate data sector 322 containing stored user information. The number of data sectors 322 included in a particular track 306 depends in part on the length (ie, circumference) of the track 306. Thus, the track 306 located in the outer zone typically contains more data sectors 322 per data wedge 316 than the track 306 located in the intermediate zone 311. Similarly, track 306 located in middle zone 311 typically contains more data sectors 322 per data wedge 316 than track 306 located in inner zone 308. In addition to including user information, each sector of data 322 may also include other data that identifies and processes the user information. The track 306 may also include one or more permanent bad sectors 322 that may be reliably written or read by the disk drive 100 circuitry. For this reason, many alternative sectors are provided in one or more alternative tracks 320 where data to be written to the bad sectors can be revectored.

According to one embodiment of the invention, the disk 108 may include one or more landing zones 120 for parking the read / write head 118 while the drive 100 is powered down. Thus, the head 118 is prevented from contacting the surface of the disk 108 unexpectedly while the disk 108 is at rest. The use of landing zone 120 to disengage head 118 from the data area on the surface of disk 108 is commonly found in disk drive 100 that handles contact start / stop (CSS) techniques. For CSS technology, the servo control system 150 may be driven during a start and stop operation of a slider (not shown) when there is insufficient rotation speed to maintain an air bearing between the surface of the disk 108 and the slider. Actuator 114 is controlled to contact zone 120. As illustrated above, landing zone 120 may be a dedicated radial region on disk 108 that is specifically textured to minimize the effect of stiction.

Referring to FIG. 4, there is a graph showing the change in friction force when the rotational speed of the disk 108 is increased with a constant acceleration from zero to the final speed. More specifically, FIG. 4 shows a graph showing the frictional forces associated with the LAP interface and the SLIP interface when the rotational speed of the disk 108 increases with a constant acceleration over a predetermined time period. Friction force is directly correlated with friction energy, which is the energy consumed in contact between the surface of the disk and the slider of the read / write head 118 through heat generation and wear of the material. Thus, the frictional force can be defined as the friction energy divided by the contact length.

FIG. 5 shows a graph showing the change in rotational speed over time when the disk 108 with both the SLIP interface and the LAP interface of FIG. 4 is accelerated with a constant acceleration. Accordingly, FIGS. 4 and 5 are illustrated in conjunction below. The frictional force associated with SLIP as the rotational speed of disk 108 increases with a constant acceleration from zero revolutions / second initial velocity (V _i ) to final velocity (V _F ) is plotted in the SLIP plot. 400 is shown. Similarly, the frictional force associated with the LAP when the rotational speed of the disk 108 increases with a constant acceleration from the initial speed (V _i) of zero revolutions / second) to the final speed (V _F ) is the LAP plot 400. Is shown. About SLIP plot 400 and the LAP plot 402, the frictional force is measured between an initial time (T _i) and the last time (T _F), the initial time (T _i), here is the start of disc rotation The final time T _F represents the desired time for the rotational speed of the disk 108 to reach the final speed V _F. By way of example only and not by way of limitation, the time for the disc to reach the final speed V _F is illustrated and illustrated in FIGS. 4 and 5 as 4 seconds. Thus, the initial time _Ti is 0 seconds and the final time T _F is 4 seconds. However, predetermined limits and variables, such as the time T _F at which the disk reaches its final speed V _F , depend upon a predetermined number of factors including, but not limited to, the disk drive design and operating specifications. It is to be appreciated that depending on the value or range of values, it may be determined.

Referring to FIG. 5, when the spindle control module 148 receives a command from the microprocessor 142 to excite rotation by the spindle hub 106 and the disk 108 attached thereto, a current is generated. It is applied to the winding (not shown) of the spindle motor 156 to start the rotation of the disk 108. Therefore, the time of 0 seconds in 5 shows the point in the rotation speed, the initial velocity (V _i), that is the disc 108 in which the disk rotation starts, and time. Thereafter, the rotational speed of the disk 108 is accelerated to a constant acceleration for 4 seconds at the final speed V _F. As such, plot 500 shows a constant increase in speed from 0 to 4 seconds. When the rotational speed of the disk 108 reaches the final rotational speed V _F , the servo control system 150 moves the read / write head 118 from the landing zone 120 to the data area 304 on the disk 108. Move to Accordingly, the final speed V _F is preferably a slider of the read / write head 118 when the head 118 accesses the surface of the disk 108 between the ID 136 and the OD 138. And a speed sufficient to create and maintain the air bearing between the surface of the disk 108.

According to an alternative embodiment, which may be referred to as an "early exit technique," the read / write head 118 may be used before the rotational speed of the disk 108 reaches its final rotational speed V _F. It may escape the landing zone 120 in time. In the disc drive 100 implementing the early escape technique, the servo control system 150 moves the read / write head 118 from the landing zone 120 to the data area on the disc 108 at the desired early escape rate (V). _D ). Preferably the desired early escape velocity V _D is such that when the head 118 is near the ID 136, it creates an air bearing between the slider of the head 118 and the surface of the disk 108. It may be sufficient speed. Typically, however, the desired early exit velocity V _D is when the head 118 moves toward the OD 138 because of the increasing large circumference that must be tracked as the head 118 moves toward the OD 138. Insufficient to hold the air bearing between the surface of the disk 108 and the slider. Thus, the acceleration of the rotational speed is final, which coincides with the time T _F at which the head 118 reaches the final rotational speed V _F from the early escape time V _D toward the OD 138. When moving up to time V _F , the rotational speed of the disk 108 should be increased to a speed sufficient to hold the air bearing.

By way of example, and not by way of limitation, the final rotational speed V _F may be set at 7200 revolutions per second. Thus, the acceleration applied to the disk 108, which is the value of the change in speed (ΔV) defined by V _F minus V _i divided by the change in time (ΔT) of 4 seconds, is 1800 revolutions per square second ( revolutions / second ² ). Thus, if an air bearing has already been formed between the slider and the surface of the disk 108 due to the rotational speed of the disk 108, if the disk 108 is rotated with an acceleration of 1800 revolutions per square second, the disk after 4 seconds, 108 rotates at 7200 revolutions per second and the servo control system 150 moves the head 118 from the landing zone 120 to the data region 304.

If the disk drive 100 uses an early escape technique, the disk drive 100 preferably increases the rotation of the disk 108 with greater acceleration compared to the disk drive 100 that does not implement the early escape technique. It is designed to be. For example, if the servo control system 150 moves the head 118 from the landing zone 120 to the data area 304 at a time corresponding to 3000 revolutions / second, the head 118 may not have been in the position of four seconds before. OD 138 may be reached. Accordingly, the disc drive designer must increase the acceleration to ensure that the rotational speed maintains the air bearings as the head 118 sweeps across the disc towards the OD 138. By way of example and not limitation, the scheduled time for the head 118 to reach the OD 138 may be three seconds. If the head 118 is close to the OD 138, if the rotational speed required to maintain the air control ring is 7200 revolutions per second, then the constant acceleration applied to the disk 108 is preferably 2400 revolutions. Squared seconds.

Referring to FIG. 4, the SLIP plot 400 is frictional against the padded slider-smooth disc structure after the first phase 404 of rapid increase and decrease in frictional force. This occurs when it increases first and then decreases slowly. The second group 406 is mainly due to the contact of the trailing edge of the slider when the pitch angle is increased due to the increasing rotational speed of the disk 108. Referring to the LAP plot 402, the second stage 406 of increased friction does not appear when the padded slider rises from the textured disk surface. The force shown in SLIP plot 400 decreases from approximately 4 grams to approximately 2 grams after 0.25 seconds, while the force shown in LAP plot 402 persists at approximately 4 grams until approximately 0.45 seconds. Thus, applying constant acceleration to the rotating disk 108 results in unwanted friction between the padded or unpadded slider and the textured or untextured landing zone 120. According to one embodiment of the invention, the multi-accelerators (multiple acceleration phase) the disk 108 between the end time (T _F) corresponding to a zero velocity in the initial time (T _i) and a final speed (V _F) Can be applied. By accelerating the disc 108 into multiple acceleration, the disk rotation until the rotation speed of the initial time to start the (T _i), the disc 108, the rotational speed disk 108 reaches hoejong speed (V _F) Is increased. The multi-stage acceleration method realized between removing the second group 406 of the friction force, and when the rotation between the disc 108 is an initial time (T _i) and the last time (T _F), the frictional force of the slider and the disk surface Decreases the length of time it takes.

6 is a graph showing the change in rotational speed over time when the disk 108 is accelerated with multiple accelerators, multiple accelerations or multi-stage accelerations in accordance with the present invention. As such, FIG. 6 illustrates a multiple accelerator method for rotating disk 108 with multiple accelerations in accordance with one embodiment of the present invention. The disk drive 100 is designed such that the final speed V _V is achieved on the disk 108 rotating at a predetermined final time T _F. Thus, the time for the disk 108 to reach the final rotational speed V _F is illustrated and shown in FIG. 6 at the final time T _F , which is several seconds. The final time T _F is preferably a predetermined time constant, while the initial time _Ti is preferably 0 seconds. By way of example and not limitation, the final time T _F is illustrated below as 4 seconds in FIG. 6 and the corresponding final rotational speed V _F is described as 7200 revolutions / second. However, predetermined limits and variables, such as the time the disk 108 reaches its final rotational speed V _F and the final rotational speed of the disk, include, but are not limited to, the disk drive design and operating specifications. It can be determined with a predetermined value and a range of values, depending on a certain number of factors.

When the spindle control module 148 receives a command from the microprocessor 142 to excite rotation by the spindle hub 106 and the disk 108 attached thereto, a current is drawn from the winding of the spindle motor 156 (shown in FIG. Not rotated) to start the rotation of the disk 108. Therefore, time of 0 seconds in FIG. 6 represent the time when the disc starts rotation, according to this, the rotational speed is the initial speed (V _i) of the disk (108). Thereafter, the rotation speed of the disk 108 is accelerated at a first acceleration 602 from the initial rotation speed _Vi to the first speed V ₁ . Thus, the plot 600 shows a constant increase in the rate of T to ₁ second from T _i seconds. Acceleration may be determined (assuming constant acceleration) by dividing the amount of change in disk 108 rotational speed by the time zone associated with the speed change. Thus, the first acceleration 602 can be determined by the following equation: a ₁ = ΔV / ΔT = (V ₁ -V _i ) / (T ₁ -T _i ) [speed / square second]. As an example for explaining FIG. 6, not for the purpose of limitation, the first speed V ₁ may be determined at 3000 revolutions / second and T ₁ may be predetermined at 1 second. Thus, the first acceleration 602 (a ₁ ) is determined as 3000 revolutions per square second.

After the rotational speed of the disk 108 reaches a first speed V ₁ , which is 3000 revolutions / second according to the above embodiment, the spindle control module 148 causes the spindle hub 106 and the disk that rotates here ( 108 is changed to a second acceleration 604 in accordance with one embodiment of the present invention. In particular, the disk 108 is then accelerated at a second acceleration 604 from the first speed V ₁ to the second speed V _N. Accordingly, plot 600 shows a constant increase in speed from T ₁ second to T _N seconds. As mentioned above, the acceleration can be determined by dividing the amount of change in the disk 108 rotational speed by the time zone associated with the speed change. Accordingly, the second acceleration 604 may be determined by the following equation: a ₂ = ΔV / ΔT = (V _N −V _i ) / (T _N −T _i ) [speed / square second].

For the sake of further exemplification but not for the purpose of limiting the invention, the second speed V _N may be determined at 5000 revolutions per second and T _N may be predetermined at 2 seconds. Thus, the second acceleration 604 (a ₂ ) is set at 2000 revolutions per square second.

After the rotational speed of the disk 108 reaches a second speed V _N , which is 5000 revolutions / second according to the above embodiment, the spindle control module 148 causes the spindle hub 106 and the disk that rotates here ( 108 may be changed to a third acceleration 606 according to an embodiment of the present invention. In particular, then the discs 108 are accelerated to a third acceleration 606, a third speed (V _{N + 1)} from the second speed (V _N). Thus, the plot 600 shows a constant increase in the rate of _{N + 1} to T _N T seconds from the beginning. As mentioned above, the acceleration can be determined by dividing the amount of change in the disk 108 rotational speed by the time zone associated with the speed change. Thus, the third acceleration 606 is given by the following equation: a ₃ = ΔV / ΔT = (V _{N + 1} −V _N ) / (T _{N + 1} −T _N ) [speed / sq sec] Can be determined.

The present invention is not limited thereto, but for the sake of further explaining the above embodiment, the third speed V _{N + 1} may be determined at 6200 revolutions / second and T _{N + 1} may be predetermined at 3 seconds. Thus, the third acceleration 606 (a ₃ ) is set at 1200 revolutions per square second.

Even after the rotational speed of the disk 108 reaches the final speed V _{N + 1} , which is 6200 revolutions per second according to this embodiment, the spindle control module 148 still rotates with the spindle hub 106 and here. The acceleration of the disk 108 can be changed to the fourth and final acceleration 608 in accordance with one embodiment of the present invention. In particular, the disk 108 is then accelerated at a third speed V _{N + 1 with} a fourth acceleration 608 to a final rotational speed and to a fourth speed V _F according to the embodiment of FIG. 6. Accordingly, plot 600 shows a constant increase in speed from T _{N + 1} sec to T _F sec. As mentioned above, the acceleration can be determined by dividing the amount of change in the disk 108 rotational speed by the time zone associated with the speed change. Thus, the fourth acceleration 608 is given by the following equation: a ₄ = ΔV / ΔT = (V _F −V _{N + 1} ) / (T _F -T _{N + 1} ) [rpm / sq sec] Can be determined.

The present invention is not limited to this, but merely to further illustrate the above embodiment, the fourth speed V _F may be determined at 7200 revolutions per second and T _F may be predetermined at 4 seconds. Thus, the fourth acceleration 608 (a ₄ ) is set at 1000 revolutions per square second.

When the rotational speed of the disk 108 reaches the final speed V _F , which is a predetermined final rotational speed of 7200 revolutions per second according to this embodiment, the servo control system 150 implements one embodiment of the present invention. According to an example, the read / write head is moved from the landing zone 120 to the data area 304 on the disc 108. In order to achieve the final rotational speed, the multi-stage acceleration method in which the final rotational speed V _F appears at the end of the fourth acceleration 608 by applying four stages of acceleration 602, 604, 606 and 608 to the disk 108 is achieved. Although shown and described in FIG. 6, the multi-stage acceleration method can use only two stages of acceleration, such that the final rotational speed V _F of the disk 108 is realized at the end of the second stage of two-stage acceleration. It should be recognized that it may be. Likewise, as long as at least two or more steps of acceleration are used, the multi-step acceleration method may also apply a certain number of steps of acceleration to the disk 108 to achieve the final rotational speed V _F.

Preferably the final rotational speed V _F is the disc and the slider of the read / write head 118 when the head 118 accesses the surface of the disc 108 between the ID 136 and the OD 138. It is defined as a speed sufficient to create and maintain an air bearing between the surfaces of 108. Since the final rotational speed V _F is achieved at a predetermined time T _F at which a predetermined number of accelerations are carried out, from landing 120 to the data region 304 between ID 136 and OD 138. The movement of may be triggered based on either timing variable T _F or speed variable V _F according to various embodiments of the present disclosure.

According to an alternative embodiment of implementing an "early escape technique", the read / write head 118 moves the landing zone 120 at a time before the rotational speed of the disc 108 reaches its final speed V _F. You can escape. In the disk drive 100 implementing the early escape technique, the servo control system 150 moves the read / write head 118 from the landing zone 120 to the data area 304 on the disk 108 at the desired early escape speed ( V _D ) Since the early escape velocity V _D is achieved at a predetermined time T _F at which a predetermined number of accelerations are performed, between landing 120 and ID 136 and OD 138. of head movement to the data region 304 may be triggered based on the early timing variables that can be referred to as the evacuation time (T _D) and a speed variable (V _D). preferably premature escape velocity (V _D May be a speed sufficient to create an air bearing between the read / write head 118 and the surface of the disk 108 when the head 118 is located near the ID 136. However, typically premature escape velocity (V _D), when the head 118 moves toward the OD (138), slicer The end more and the disk 108 does not sufficient to maintain an air bearing between the surface, the acceleration, the head 118, the disk 108 from the early evacuation time (T _D) is applied to the rotating disk 108 for When moving towards OD 138 until the final time T _F corresponding to the time to reach rotation speed V _F , it should be such that the rotation speed is increased to a speed sufficient to hold the air bearing.

Referring to FIG. 7, FIG. 7 is a graph showing a change in friction force when the rotational speed of the disk 108 increases from the initial speed _Vi to the final rotational speed V _F. More specifically, FIG. 7 shows two graphs showing the frictional force over time in which the rotational speed of disk 108 increases both constant acceleration (plot 702) and multiple accelerators (plot 700). . When the rotational speed of the disk 108 increases with a multiple accelerator according to one embodiment of the invention from speed 0 (V _i ) to final rotational speed (V _F ), the frictional force associated with the SLIP interface is increased in the first SLIP plot ( 700). Likewise, when the rotational speed of the disk 108 increases with a constant acceleration from speed 0 (V _i ) to the final rotational speed V _F , the frictional force associated with the SLIP interface is shown in the second SLIP plot 702.

Claim 1 SLIP plot 700 and the No. 2 SLIP plot 702 with respect to the both, the frictional force is measured between an initial time (T _i) and the last time (T _F), the initial time (T _i), here rotation And the final time T _F indicates that when the head 118 moves towards the OD 138, the rotational speed of the disk 108 is between the surface of the disk 108 and the slider of the head 118. Indicate the desired time to reach the final rotational speed V _F sufficient to hold the bearing. By way of example and not limitation, the time T _F at which disk 108 reaches the final rotational speed V _{F is} shown and described as 8 seconds in FIG. 7. Thus, the initial time _Ti is 0 seconds and the final time T _F is 8 seconds. However, predetermined limits and variables, such as, but not limited to, disk drive design and operating specifications, such as final speed (V _F ) and the time (T _F ) at which the disk reaches final rotational speed (V _F ). Depending on the predetermined number of factors to be determined, it may be determined as a predetermined value or a range of values.

With reference to FIG. 7, the second SLIP plot 702 has a frictional force that, after the first phase 704 of rapid increase and decrease of frictional force, for the padded slider-smooth disc structure. It occurs at the point where it increases and then decreases slowly. The second phase is mainly due to the contact of the trailing edge of the slider when the pitch angle is increased due to the increasing rotational speed of the disk 108. A first slider and a landing zone for applying the SLIP plot 700, the disk 108 a, a multi-accelerators, as shown in between an initial time (T _i) and the last time (T _F), the head (118) (120 The second group of frictional forces between the surfaces of h) is removed. Furthermore, applying multiple accelerators to the rotating disk 108 causes frictional forces to be realized in a shorter time between the slider and the landing zone 120 surface, which means that two plots in the first phase 704 of frictional force ( The difference between 700 and 702 is shown. The frictional force shown by the first SLIP plot 700 decreases from approximately 4.2 grams to approximately 2 grams after 0.25 seconds, while the frictional force shown in the second SLIP plot 702 persists at approximately 4 grams until approximately 0.6 seconds. . Although not shown, the application of multiple accelerators from the initial speed (V _i ) zero revolutions / second to the final rotation speed (V _F ) in the disk drive 100 using the LAP and LZT interfaces is a potential second to any potential frictional force. Removing the group and reducing the length of time the friction force is realized between the slider and the disk surface in a manner substantially similar to that illustrated in FIG.

According to one embodiment, the present invention provides a command program that can be executed by a computer system to accelerate the data storage disk 108 with multiple accelerations to achieve the final rotational speed V _{F of the} rotating disk 108. It may be implemented as a computer-readable program storage device that specifically implements. Accordingly, the logical operations of the various embodiments of the present invention may include (1) a series of program modules or computer execution behavior models acting on a computer system and / or (2) interconnected machine logic circuits within a computer system or It can be implemented as a circuit module. The implementation is a matter of choice depending on the performance requirements of the computer system implementing the invention. Accordingly, logical operations that meet the embodiments of the invention illustrated herein are variously referred to as operations, structural devices, behavior models, and modules. The acts, rescue devices, behavioral models and modules may be implemented in software, firmware, special purpose digital logic, and any combination thereof without departing from the spirit and scope of the invention as defined by the appended claims. It will be apparent to those skilled in the art.

Figure 8 illustrates the operation associated with the multi-step method for accelerating rotating speed threshold (V _TH), the disc 108 up from the initial rotational speed (V _i). In particular, the multi-stage acceleration method 800 begins and the initial rotational speed of zero revolutions / predetermined threshold rotational speed from the second of by the disk 108 at an initial time (T _i), according to one embodiment of the invention rotation (V _In order to determine the rotational speed of the disk 108 in _TH ), the disk 108 is subjected to multiple acceleration stages, multiple accelerations or multiple accelerators. Preferably the multi-stage acceleration method accelerates the disk 108 at multiple accelerations such that the threshold rotational speed V _TH is realized at a predetermined threshold time T _TH . According to one embodiment, the threshold speed V _TH is read with the disk 108 surface as the head 118 exits the landing zone 120 and enters the data area 304 on the disk 108 surface. Is a speed sufficient to create an air bearing between the recording heads 118. Accordingly, the threshold speed V _TH may be a final speed V _F different from one embodiment of the present invention or a desired early escape rate V _F according to an alternative embodiment of the present invention. As shown in greater detail in FIG. 9, if the critical speed V _TH is the final speed V _F , then the critical speed V _TH is the head 118 across the disk 108 toward the outer diameter 138. When moving, it is a speed sufficient to create and maintain an air bearing. Conversely, if the threshold speed V _TH is the desired early escape speed V _D , then typically the threshold speed V _TH is the head 118 moving radially toward the outer diameter 138 across the disk 108. When it does not hold the air bearings, it is just enough speed to produce. Thus, the multi-stage acceleration method shown and described in FIG. 10 moves the disk 108 past the threshold speed V _TH to ensure that the air bearing is retained as the head 118 continues to move toward the outer diameter 138. Indicates continued acceleration.

The multi-step acceleration method 800 includes an operational flow that starts the startup operation 802 and ends the termination operation 814. In particular, the multi-step acceleration method 800 begins in a startup operation 802 when the computer microprocessor 142 sends a read / write command to the servo control system 150 and the spindle control module 148. The read / write command causes the spindle control module 148 to begin spinning one or more disks 108, from which data is read from or written to the read / write head 118 controlled by the servo control system 150. do. For simplicity, the multi-step acceleration method 800 is described below with reference to a single disk 108 of the disk drive 100.

The operation flow proceeds from the start operation 802 to the receive operation 804. Receive operation 804 receives a read / write command issued by microprocessor 142. After the read / write command is received, the operational flow proceeds to an initial acceleration operation 806. The initial acceleration operation 806 is the disk 108 at the initial acceleration until the disk 108 reaches the first rotational speed (V ₁ ) from the initial rotational speed (V _i ) which is zero revolutions / second according to one embodiment. Accelerate. When the disk 108 reaches the first rotational speed V ₁ , the operation flow proceeds to the next acceleration operation 808. The next acceleration operation 808 accelerates the disk 108 with the second acceleration until the disk 108 reaches the second rotational speed V _N. When the disk 108 reaches the second rotational speed V _N , the operation flow continues to the speed determination operation 810. Speed determination operation 810 determines whether the current rotational speed of disk 108 has reached a critical rotational speed V _TH . The critical rotational speed V _TH may be defined as a predetermined value or range of values depending on a predetermined number of factors, including but not limited to disk drive design and operating specifications.

If the speed determination operation 810 determines that the current rotation speed is the desired final rotation speed V _F , the operation flow proceeds to the head escape operation 812. Head escape operation 812 may include data area 304 on the surface of disk 108 from landing zone 120 such that head 118 accesses track 306 on disk 108, that is, writes to or reads from track. ) Moves the read / write head 118. As illustrated above and described in more detail below, the head 118 may escape the landing zone 120 at either the final speed V _F or the desired early escape speed V _D. Accordingly, the track 306 on the disc 108 accessible by the head 118 may cause the head 118 to escape the landing zone 120 at the final rotational speed V _F or the early escape speed V _D. Depends on If the head 118 escapes at the final speed V _F , all tracks 306 on the disk 108 are accessible to the head 118. Conversely, if the head escapes at an early escape speed V _D , fewer tracks than the tracks 306 on the disc are accessible to the head 118.

If the speed determination operation 810 determines that the current rotation speed is not the predetermined threshold speed V _TH , the operation flow returns to the next acceleration operation 808. The disk 108 is then accelerated to an acceleration different from the previous acceleration applied by the next acceleration operation 808 and the operation flow is then accelerated to the next acceleration operation 808 and speed until the critical rotational speed V _TH is realized. Processing continues between decision operations 810. After the read / write head 118 is moved out of the landing zone 120, the operation flow ends the terminating operation 814.

9 is a multi-stage acceleration method for rotating the final rotation speed (V _F) the disk 108 to rotate from the initial velocity (V _i) geolcheo the time (T _F -T _i) predetermined in accordance with one embodiment of the present invention Shows the operation associated with the. In particular, the multi-stage acceleration method 900 disk to determine an initial time (T _i) on the disk 108, the disk 108 rotation speed (V _F) start rotating and the determined rotation speed of the disk 108 in advance by Apply multiple acceleration stages, multiple accelerations or multiple accelerators to 108. Thus, the threshold speed V _TH illustrated in FIG. 9 is a predetermined final speed V _F. Preferably, the multi-stage acceleration method 900 accelerates the disk 108 at multiple accelerations such that the final rotational speed V _F is realized at a predetermined final time T _F. Preferably the rotational speed of the disk 108 is a number of 0 revolutions / second at an initial time (T _i). Presets such as the initial rotational speed (V _i ), the time when the disk rotation starts (T _i ), the final rotational speed (V _F ) and the time (T _F ) at which the disk 108 reaches the final rotational speed (V _F ). The determined limits and variables may be determined within a predetermined value or range of values, depending on, but not limited to, the disk drive design and operating specification, and only a certain number of factors to include.

The multi-step acceleration method 900 includes an operational flow that starts the start operation 902 and ends the end operation 924. In particular, the multi-stage acceleration method 900 begins in a startup operation 902 when the computer microprocessor 142 sends a read / write command to the servo control system 150 and the spindle control module 148. The read / write command causes the spindle control module 148 to begin spinning one or more disks 108, from which data is read from or written to the read / write head 118 controlled by the servo control system 150. do. For simplicity, the multi-stage acceleration method 900 is described below with reference to a single disk 108 of the disk drive 100.

The operation flow proceeds from the startup operation 902 to the reception operation 904. Receive operation 904 receives a read / write command issued by microprocessor 142. After the read / write command is received, the operational flow proceeds to an initial acceleration operation 906. The initial acceleration operation 906 is the disk 108 at the initial acceleration until the disk 108 reaches the first rotational speed (V ₁ ) from the initial rotational speed (V _i ) which is zero revolutions / second according to one embodiment. Accelerate. According to one embodiment of the invention, the disc 108 reaches the initial time (T _i) a first rotational speed following the beginning of the next predetermined time zone of the (V _1). Preferably said initial predetermined time zone ends at time T ₁ . Accordingly, the operation flow proceeds from the initial acceleration operation 906 to the first query operation 908. The first query operation 908 determines whether the disk 108 is rotating during the initial predetermined time zone by comparing the current time of disk rotation with the time T ₁ . If the current time is not equal to T ₁ , the operation flow returns to initial acceleration operation 906 and the rotation of disk 108 continues to accelerate with initial acceleration until time T ₁ . At time T ₁ , the operation flow proceeds to the next acceleration operation 910.

The next acceleration operation 910 accelerates the disk 108 from the initial acceleration until the disk 108 reaches the next rotational speed. According to one embodiment of the invention, the disk 108 reaches the next rotational speed V _N starting at time T ₁ and following the second predetermined time zone ending at time T _N. Accordingly, the operation flow proceeds from the next acceleration operation 910 to the second query operation 912. The second query operation 912 determines whether the disk 108 is rotating during the second predetermined time period by comparing the current time of disk rotation with the time T _N. If the current time is not equal to T _N , the operation flow proceeds back to the next acceleration operation 906 and the rotation of the disk 108 continues to accelerate with the next acceleration until time T _N. At time T _N , the operational flow proceeds to a third query operation 914.

The third query operation 914 reaches the initial velocity (V _i), a predetermined end time and by comparing the length of the current zone of the disk rotating disk 108, the current rotational speed of a predetermined final rotational speed (V _F) from the Determine if you did. Preferably the predetermined final time zone ends at time T _F. According to one embodiment of the invention, the time T _F is such that when the head 118 accesses the surface of the disk 118 between the ID 136 and the OD 138, the rotational speed of the disk 108 is increased. It may be predetermined with a time sufficient to create and maintain an air bearing between the slider of the read / write head 118 and the surface of the disk 118. Further, the final rotational speed V _F and time T _F may be set to a predetermined value or range of values depending on the disc drive design and operating specification, including but not limited to a predetermined number of factors to include. Can be.

If the third query operation 914 determines that the length of the current time zone is equal to the predetermined final time zone, the operation flow proceeds to the head escape operation 916. Head escape operation 916 causes head 118 to access track 306 on disk 108. That is, the read / write head 118 is moved from the landing zone 120 to the data area 304 to be written to or read from the track. Once the head 118 is moved to the data area 304, the operation flow ends the terminating operation 924. However, if the third query operation 914 determines that the length of the current time zone is not equal to the predetermined final time zone, the operation flow proceeds to subsequent acceleration operation 920. The subsequent acceleration operation 920 accelerates the disk 108 at a third acceleration different from the second acceleration applied by the next acceleration operation 910. Subsequent acceleration operation 920 accelerates the disk 108 until the disk 108 reaches the next rotational speed V _{N + 1} . According to one embodiment of the invention, disc 108 is the time (T _N) start, and the time (T _{N + 1)} of claim 3 in advance, subsequent to the determined time, and then the rotational speed (V _{N + 1)} of the end in To reach. Accordingly, the operation flow proceeds from the subsequent acceleration operation 920 to the fourth query operation 922.

The fourth query operation 922 determines whether the current time is time T _{N + 1} . If the current time is not the time T _{N + 1} , the operation flow proceeds back to the subsequent acceleration operation 920 and the rotation of the disk 108 continues to accelerate with a third acceleration until time T _{N + 1} . . At time T _{N + 1} , the operation flow proceeds to third query operation 914 and continues to head escape operation 916 if the current time is equal to time T _F. However, if disk 108 is not spinning for the final predetermined time zone ending at time T _F , the operation flow returns to subsequent acceleration operation 920 and continues as illustrated above. If the operational flow proceeds from the third query operation 914 to the subsequent acceleration operation 920, the subsequent acceleration operation 920 accelerates the disk 108 at an acceleration different from the previously applied acceleration. Accordingly, subsequent acceleration operations 920 may accelerate the disk 108 with accelerations such as third, fourth, fifth, sixth, etc. where each acceleration is different in magnitude from the previous acceleration, but yes. For example, although the fifth acceleration is different from the fourth acceleration, the sixth acceleration may be the same size as the third acceleration. For clarity and motion flow purposes, i.e. to distinguish the acceleration from the acceleration applied by the operation 920 on the previous operation flow progression, the acceleration applied by the subsequent acceleration operation 920 is then referred to as "Next acceleration ( next acceleration rate). The operational flow is followed by a third query operation 914 where the disk 108 rotates for a predetermined final time zone ending at time T _F , where the operational flow proceeds to a head escape operation 916 and continues as illustrated above. It continues between subsequent acceleration operations 920, fourth query operations 922 and third query operations 914 until it is determined.

10 is a multi-stage for rotating the disc 108 over a predetermined time (T _i -T _F) up to the final speed (V _F) from the initial rotational speed (V _i) in accordance with an alternate embodiment of the present invention An operation associated with the acceleration method 1000 is shown. Multi-stage acceleration method 1000 is a multi-acceleration step to determine the rotation speed of the disk 108 at the initial time begins to rotate by the disc 108 in the (T _i) and a predetermined final rotational speed (V _F), a multi- Acceleration, multiple acceleration stages, and multiple accelerators are applied to disk 108. Preferably, the multi-stage acceleration method 1000 accelerates the disk 108 with multiple accelerations such that the final rotational speed V _F is realized at a predetermined final time T _F. Preferably the rotational speed of the disk 108 is a number of 0 revolutions / second at an initial time (T _i). The multi-stage acceleration method 1000 is a multistage acceleration method, such as the method 900 of FIG. 9, which reads from the landing zone 120 to the data area 304 on the disk 108 at the desired early escape rate V _D. Use an action associated with early escape techniques to move the recording head 118. Thus, the threshold speed V _TH illustrated in FIG. 10 is the desired early escape speed V _D. The desired early escape rate (V _D ), the final rotational speed (V _F ) of the disk 108 and the disk 108 reach both the desired early escape rate (V _D ) and the final rotational speed (V _F ). Predetermined limits and variables, such as time T _F , may be set to a predetermined value or range of values in accordance with a predetermined number of factors including, but not limited to, disk drive design and operating specifications.

The multi-stage acceleration method 1000 includes an operational flow that begins with a startup operation 1002 and ends with a termination operation 1024. In particular, the multi-stage acceleration method 1000 begins in the startup operation 1002 when the computer microprocessor 142 sends a read / write command to the servo control system 150 and the spindle control module 148. The read / write operation begins with the spindle control module 148 spinning one or more disks 108 whose data is read from or written to the disk 108 by a read / write head whose data is controlled by the servo control system 150. Do it. For simplicity, the multi-stage acceleration method 1000 is illustrated below with reference to a single disk 108 of the disk drive 100.

The operation flow proceeds from the startup operation 1002 to the reception operation 1004. Receive operation 1004 receives a read / write command issued by microprocessor 142. After the read / write command is received, the operation flow proceeds to the initial acceleration operation 1006. The initial acceleration operation 1006 may be performed at an initial acceleration rate from the initial rotational speed V _i , which is zero revolutions / second, until the disk 108 reaches the first rotational speed V ₁ , according to _{one embodiment} . Accelerate. According to one embodiment of the invention, the disc 108 reaches the initial time (T _i) first rotation speed following the beginning of the next predetermined time zone of the (V _1). Preferably the initial predetermined time zone ends at time T ₁ . The operation flow proceeds simultaneously from the initial acceleration operation 1006 to the first query operation 1008 and the speed query operation 1015. The first query operation 1008 determines whether the disk 108 is rotating during an initial predetermined time period by comparing the time T ₁ with the current time of disk rotation. If the current time is not equal to the time T ₁ , the operation flow returns to the initial acceleration operation 1004 so that the rotation of the disk 108 continues to accelerate with the initial acceleration until the time T ₁ .

The speed query operation 1015 determines whether the rotational speed of the disk 108 has reached the desired early escape speed V _D. If the speed query operation 1015 determines that the early escape speed V _D has been reached, the operation flow proceeds to an early escape operation 1017. The early escape operation 1017 is performed by the data on the surface of the disc 108 from the read / write head 118 so that the head 118 accesses the track 306 on the disc 108, that is, writes to or reads from the track. Move read / write head 118 to region 304. Preferably the desired early escape velocity V _D is to create and maintain an air bearing between the slider of the head 118 and the surface of the disk 108 when the head 118 is near the ID 136. Although the speed may be sufficient for, the desired early escape velocity (V _D ) is typically sufficient to maintain an air bearing between the slider and the surface of the disk 108 when the head 118 moves toward the OD 138. Insufficient speed. This situation is mainly due to the increasing large circumference that must be tracked as the head 118 moves towards the OD 138. Thus, the flow of operations may be the first from early escape operation 1017 to ensure that the rotational speed of disk 108 increases at a speed sufficient to maintain the air bearing as head 118 moves toward OD 138. Proceeds to query operation 1008. The operation flow then continues to query operation 1008 and continues between query operation 1008 and initial acceleration operation 1006 until time T ₁ .

However, if the speed query operation 1015 determines that the early escape speed V _D has not been reached, the operation flow does not proceed to the early escape operation 1017 but proceeds to the first query operation 1008 and at time T _1. It continues until the initial acceleration operation 1006, the first query operation 1008 and the speed query operation 1015. Regardless of whether the head 118 has been moved from the landing zone 120 to the data region 304, at time T ₁ the operation flow proceeds to the next acceleration operation 1010.

The next acceleration operation 1010 accelerates the disk 108 at a second acceleration different from the initial acceleration until the disk 108 reaches the next rotational speed V _N. According to one embodiment of the invention, the disk 108 reaches the next rotational speed V _N subsequent to the second predetermined time zone starting at time T ₁ and ending at time T _N. The operation flow proceeds simultaneously from the next acceleration operation 1010 to the second query operation 1012 and the speed query operation 1015. The second query operation 1012 determines whether it is rotating during the second predetermined time period by comparing the current time of disk rotation with the time T _N. If the current time is not equal to the time T _N , the operation flow returns to the next acceleration operation 1010 so that the rotation of the disk 108 continues to accelerate with the second acceleration until time T ₁ .

The speed query operation 1015 determines whether the rotational speed of the disk 108 has reached the desired early escape speed V _D. If the speed query operation 1015 determines that the early escape speed V _D has been reached, the operation flow proceeds to an early escape operation 1017. As illustrated above, the early escape operation 1017 may be performed by the disc 108 from the landing zone 120 such that the head 118 accesses the track 306 on the disc 108, that is, writes to or reads from the track. Move the read / write head 118 to the data area 304 on the surface of the. Preferably, the desired early escape velocity V _D is such that when the head 118 is near the ID 136, it creates and maintains an air bearing between the slider of the head 118 and the surface of the disk 108. Although the speed may be sufficient for, the desired early escape velocity (V _D ) is typically insufficient to maintain an air bearing between the slider and the surface of the disk 108 when the head 118 moves toward the OD 138. One speed. This situation is mainly due to the increasing large circumference that must be tracked as the head 118 moves towards the OD 138. Thus, the operation flow is second from the early escape operation 1017 to ensure that the rotational speed of the disk 108 increases at a speed sufficient to hold the air bearing as the head 118 moves toward the OD 138. Proceeds to query operation 1012. The operation flow then continues to the second query operation 1012 and continues between the second query operation 1012 and the next acceleration operation 1010 until time T _N.

However, if the speed query operation 1015 determines that the early escape speed V _D has not been reached, the operation flow does not proceed to the early escape operation 1017 but proceeds to the second query operation 1012 and at time T _N. It continues until the next acceleration operation 1010, second query operation 1012 and speed query operation 1015. Regardless of whether the head 118 has been moved from the landing zone 120 to the data region 304, at time T _N the operation flow proceeds to the next acceleration operation 1014.

The third querying operation 104 determines the final rotational speed V _F by comparing the length of the current time zone of the disk rotation from the initial speed with a predetermined final time zone ending at time T _F. Determine if you have reached According to one embodiment of the invention, the time T _F is associated with the surface of the disk 108 when the head 118 accesses the surface of the disk 108 between the ID 136 and the OD 138. It may be predetermined with a time sufficient to generate and maintain an air bearing between the sliders of the read / write head 118. Further, the final rotational speed V _F and time T _F can be set to a predetermined value or range of values depending on the disc drive design and operating specification, but not limited to, depending on the predetermined number of factors included.

If the third query operation 1014 determines that the length of the current time zone is equal to the predetermined final time zone, the flow of operations proceeds to a head escape operation 1016. The head escape operation 1016 is performed by the data area on the surface of the disk 108 from the landing zone 120 so that the head 118 accesses the track 306 on the disk 108, that is, writes to or reads from the track. Move read / write head 118 to 304. Since the disk 108 is spinning at the final rotational speed V _F at time T _F , the air bearing is between the head 118 and a predetermined position between the OD 138 and ID 136 on the disk. Is maintained at. If the head 118 is moved to the data area 304, the operation flow ends with a terminating operation 1024.

However, if the third query operation 1014 determines that the length of the current time zone is not equal to the predetermined final time zone T _F , the operation flow proceeds to a subsequent acceleration operation 1020. The subsequent acceleration operation 1020 accelerates the disk 108 at a third acceleration different from the second acceleration applied by the next acceleration operation 1010. Subsequent acceleration operation 1020 accelerates the disk 108 until the disk 108 reaches the next rotational speed V _{N + 1} . According to one embodiment of the invention, disc 108 is the time (T _N), then the rotational speed (V _{N + 1)} for following the start and the predetermined time of the third ends at time (T _{N + 1)} in the To reach. The operation flow proceeds simultaneously from a subsequent acceleration operation 1020 to a fourth query operation 1022 and a speed query operation 1015. The fourth query operation 1022 determines whether the disk 108 is rotating for a third predetermined time period by comparing the current time of disk rotation with the time T _{N + 1} . If the current time is not equal to the time T _{N + 1} , the operation flow returns to the subsequent acceleration operation 1020 and the rotation of the disk 108 continues to accelerate with a third acceleration until time T _{N + 1} . do.

The speed query operation 1015 determines whether the rotational speed of the disk 108 has reached the desired early escape speed V _D. If the speed query operation 1015 determines that the early escape speed V _D has been reached, the operation flow proceeds to an early escape operation 1017. As described above, the early escape operation 1017 allows the disc 108 from the landing zone 120 to allow the head 118 to access the track 306 on the disc 108, ie write to and read from the track. Move the read / write head 118 to the data area 304 on the surface of the. Preferably the desired early escape velocity V _D is a speed sufficient to create and maintain an air airing between the slider of the head 118 and the surface of the disk 108 when the head 118 is near the ID. Although typically desired, the desired early escape velocity V _D is an insufficient velocity to maintain an air bearing between the slider and the surface of the disk 108 when the head 118 moves toward the OD 138. . This situation is mainly due to the increasing large circumference that must be tracked as the head 118 moves towards the OD 138. Thus, the flow of motion is the fourth from early escape operation 1017 to ensure that the rotational speed of the disk 108 increases at a speed sufficient to maintain the air bearing as the head 118 moves toward the OD 138. Proceed to query operation 1022. The operation flow then continues to fourth query operation 1022 and continues between fourth query operation 1012 and subsequent acceleration operation 1020 until time T _N.

However, if the speed query operation 1015 determines that the early escape speed V _D has not been reached, the operation flow does not proceed to the early escape operation 1017 but proceeds to the fourth query operation 1022 and time T _{N + 1} ) continues between subsequent acceleration operations 1020, fourth query operation 1022 and speed query operation 1015. Regardless of whether the head 118 has been moved from the landing zone 120 to the data region 304, the operation flow proceeds to a third query operation 1014 until time T _{N + 1} .

At time T _{N + 1} , the operation flow proceeds to a third query operation 1014, and if the length of the current time zone is equal to the predetermined final time zone ending at time T _F , then head escape operation 1016. Continue to However, if disk 108 is not spinning for a predetermined final time zone ending at time T _F , the operation flow returns to subsequent acceleration operation 1020 and proceeds as described above. In each case where the operation flow proceeds from the third query operation 1014 to the subsequent acceleration operation 1020, the subsequent acceleration operation 1020 accelerates the disk 1080 with an acceleration different from the previously applied acceleration. Accordingly, subsequent acceleration operations 1020 may accelerate the disk 108 with accelerations such as third, fourth, fifth, sixth, etc. where each acceleration is different in magnitude from the previous acceleration, but yes. For example, although the fifth acceleration is different from the fourth acceleration, the sixth acceleration may be the same size as the third acceleration. For clarity and motion flow purposes, i.e. to distinguish the acceleration from the acceleration applied by the operation 1020 on the previous operation flow progression, the acceleration applied by the subsequent acceleration operation 1020 is then referred to as "next acceleration ( next acceleration rate). The operation flow may be followed by subsequent acceleration operations 1020, speed query operations 1015, and third operations until the third query operation 1014 determines that the disk 108 is rotating for a predetermined final time zone ending at time T _F. 4 is going to proceed between query operation 1022 and the third query operation 1014, from the time (T _F), the flow operation proceeds to the head escape operation 1016. proceeding as exemplified above.

In summary, the present invention may be considered as a method (such as in operation 800) for increasing the rotational speed of a data storage disk (such as 108) to a disk drive (such as 100). The method (such as in operation 800) may include: (such as operation 806) accelerating a data storage disk (such as 108) at a first acceleration from the initial rotational speed to a first predetermined rotational speed, Accelerating a data storage disk (such as 108) (such as operation 808) with a second acceleration from a predetermined rotational speed of 1 to a critical rotational speed, and the data storage disk (such as 108) is critical. When rotating at rotational speed, move the transducer (such as 118) from the landing zone (such as 120) to the data area (such as 304) on the surface of the data storage disk (such as 108). Step (such as operation 812) The critical rotational speed creates and maintains an air bearing between the transducer (such as 118) and the surface of the disk (such as 108).

According to one embodiment, the critical rotational speed is such that the transducer (such as 118) is radial across the disk (such as 108) between the inner diameter (such as 136) and the outer diameter (such as 138). It can be the final rotational speed to create and maintain the air bearing when moving to. Accordingly, the acceleration step (such as operation 808) accelerates the data storage disk (such as 108) with the second acceleration from the first predetermined rotational speed to the second predetermined rotational speed (operation ( Step), and if the second predetermined rotational speed is not equal to the threshold rotational speed, storing the data (such as 108) with one or more accelerations from the second predetermined rotational speed to the critical rotational speed. Accelerating the disk (such as operation 920). The acceleration step (such as operation 806) is such that the initial time corresponding to the rotational speed of the disk (such as (108)) becomes equal to the initial rotational speed, and the rotational speed of the disk (such as (108)) Accelerating the data storage disk (such as 108) at a first acceleration between a corresponding first predetermined time when the first predetermined rotational speed is reached. Similarly, the acceleration phase (such as operation 806) may be used to determine a second acceleration between the first predetermined time and a threshold time corresponding to when the rotational speed of the disk (such as 108) reaches the critical rotational speed. And accelerating the data storage disk (such as 108). Accordingly, the moving step (such as operation 812) may include displacing the transducer (such as 118) from the landing zone (such as 120) at a threshold time.

According to an alternative embodiment, the critical rotational speed is such that when the transducer (such as 118) escapes the landing zone (such as 120) to access the data area (such as 304), the air bearing It may be an early escape rate that produces. Accordingly, the method (such as operation 800) accelerates the data storage disk (such as 108) (such as operation 1010 or 1020) at a third acceleration from the critical rotational speed to the final rotational speed. It may include. The final rotational speed maintains the air bearings when the transducer (such as 118) moves radially toward the outer diameter of the data storage disk (such as 108) (such as 108). The acceleration step (such as operation 806) is such that the initial time corresponding to the rotational speed of the disk (such as 108) is equal to the initial rotational speed, and the rotational speed of the disk (such as (108)) is reduced. Accelerating the data storage disk (such as 108) (such as 108) with a first acceleration between the corresponding first predetermined time when a predetermined rotational speed of 1 is reached. Can be. Similarly, the acceleration phase (such as operation 808) may be performed at a second acceleration time (108) between the first predetermined time and a threshold time at which the rotational speed of the disk (such as 108) corresponds to the critical rotational speed. Accelerating the data storage disk (such as operation 1010). Accordingly, the moving step (such as operation 812) may displace the transducer (such as 118) from the landing zone (such as 120) at a threshold time (such as operation 1016 or 1017). It may include. Furthermore, the acceleration phase (such as operation 1010 or 1020) is the final acceleration between the threshold time and the final predetermined time corresponding to when the rotational speed of the disk (such as (08)) reaches the final rotational speed. Accelerating the data storage disk (such as 108).

According to another embodiment, the accelerating step (such as operation 800) operates the data storage disk (such as 108) at a second acceleration from the first predetermined rotational speed to the second predetermined rotational speed. Accelerating (such as 1010), and if the second predetermined rotational speed is not equal to the threshold rotational speed, the one or more accelerations (such as 108) from the second predetermined rotational speed to the critical rotational speed. Accelerating the data storage disk (such as operation 1020.) Furthermore, the accelerating step (such as operation 1010 or 1020) may comprise a third from a threshold rotational speed to a second predetermined rotational speed. Accelerating the data storage disk (such as 108) (such as operation 1010 or 1020) with an acceleration of, and if the second predetermined rotational speed is not equal to the threshold rotational speed, the second predetermined From the rotational speed of one or more of the following acceleration to the final rotational speed (such as 108) may include a step of acceleration.

The invention may also be practiced by a computer system to perform a method (such as operation 800) to increase the rotational speed of a data storage disk (such as (108)) in a disk drive (such as (100)). It can be considered as a computer readable program storage device that specifically realizes a program of instructions that can be.

The invention also contemplates a data storage disk (such as (108)) and a disk (such as (108)) that can be rotatably mounted to a base plate (such as (102)) and operable to spin at a rotational speed. It can be implemented as a disk drive (such as (100)) that includes an actuator arm (such as (114)) mounted to a base plate (such as (102)). A disk drive (such as (100)) can be implemented as (( A transducer (such as 118) attached to an actuator arm (such as 114) to enable the transducer (such as 118) to move over the surface of the disk (such as 108). The transducer (such as 118) is parked on the landing area (such as 120) on the surface of the disk (such as 108). The disk drive (such as 100) is also critical from the initial rotational speed. Save data (such as (108)) with multiple accelerations up to rotation speed Means for accelerating the disk (such as 806 and 808) and from a landing zone (such as 120) to a data region (such as 304) on the disk (such as 108) (118) Means (such as 812) for moving the transducer at a critical rotational speed, such as 812. The critical rotational speed is such that the transducer (such as 118) is in accordance with one embodiment of the present invention (138). Between the outer surface of the disk (such as (118)) and the transducer (such as (118)) when moving radially across the disk (such as (108)) between the outer diameter (such as 136) and the inner diameter such as (136). May be the final rotational speed for creating and maintaining the air bearing, and the critical rotational speed may also be such that the transducer (such as 118) escapes the landing zone (such as 120) in accordance with an alternative embodiment of the present invention. When accessing a data area (such as 304), there is a gap between the transducer (such as (118)) and the surface of the disk (such as (108)). It may be premature escape velocity to produce bearings.

It will be apparent that the invention is not only unique but well adapted to achieve the above-mentioned objects and advantages. While preferred embodiments are now illustrated for purposes of disclosure, various changes and modifications can be made within the scope of the present invention. For example, a multi-step acceleration method can be used to retract the read / write head from the data area to the landing zone or load / unload ramp during down of the disk drive power supply. Furthermore, the multistage acceleration method may also apply only two different acceleration stages to the disc, where the second stage is maintained at a constant acceleration until the final rotational speed is achieved at the rotational speed of the disc. In addition, the read / write head may escape the landing zone at a predetermined time corresponding to the desired early escape speed. Thus, the determination of whether the head will exit the landing zone can be based on the predetermined time indicating that the current rotational speed has reached the desired escape speed. It will be apparent to those skilled in the art that many other changes are possible without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (28)

A method for increasing the rotational speed of a data storage disk of a disk drive, the method comprising: (a) accelerating the data storage disk with a first acceleration from the initial rotational speed to a first predetermined rotational speed; (b) accelerating the data storage disk at a second acceleration from the first predetermined rotational speed to a critical rotational speed; And (c) moving the transducer from a landing zone to a data area on the data storage disk surface as the data storage disk rotates at the critical rotational speed, Wherein the critical rotational speed creates and maintains an air bearing between the transducer and the disk surface. The method of claim 1, The critical rotational speed is the disk rotational speed, which is the final rotational speed at which the transducer creates and maintains the air bearing when the transducer moves radially across the disk between an inner diameter and an outer diameter. How to increase. The method of claim 2, The acceleration step (b), (i) accelerating the data storage disk with the second acceleration from the first predetermined rotational speed to a second predetermined rotational speed; And (ii) if the second predetermined rotational speed is not equal to the threshold rotational speed, accelerating the data storage disc with one or more next accelerations from the second predetermined rotational speed to the threshold rotational speed. Including disk rotation speed increase method. The method of claim 2, Said acceleration step (a) accelerating said data storage disk at said first acceleration between an initial time corresponding to said initial rotational speed and a first predetermined time corresponding to said first predetermined rotational speed; It includes; And said accelerating step (b) comprises accelerating said data storage disk with said second acceleration between said first predetermined time and a threshold time corresponding to said critical rotation speed. The method of claim 4, wherein And said moving step (c) comprises displacing said transducer from said landing zone at said critical time. The method of claim 1, Wherein the critical rotational speed is an early exit velocity that generates the air bearing when the transducer exits the landing zone to access the data area. The method of claim 6, (d) when the transducer is located at an outer diameter of the data storage disk, further comprising accelerating the data storage disk with a third acceleration from the critical rotation speed to a final rotation speed that holds the air bearing. How to increase rotation speed. The method of claim 7, wherein The acceleration step (a) may include accelerating the data storage disk with the first acceleration between an initial time corresponding to the initial rotational speed and a first predetermined time corresponding to the first predetermined rotational speed. Including; And said accelerating step (b) comprises accelerating said data storage disk with said second acceleration between said first predetermined time and a threshold time corresponding to said critical rotation speed. The method of claim 8, And said moving step (c) comprises displacing said translation length from said landing zone at said critical time. The method of claim 9, And said accelerating step (d) comprises accelerating said data storage disk with said third acceleration between said threshold time and a final predetermined time corresponding to said final rotational speed. The method of claim 7, wherein The acceleration step (b), (i) accelerating the data storage disk with the second acceleration from the first predetermined rotational speed to a second predetermined rotational speed; And (ii) if the second predetermined rotational speed is not equal to the threshold rotational speed, accelerating the data storage disc with one or more next accelerations from the second predetermined rotational speed to the threshold rotational speed. Including disk rotation speed increase method. The method of claim 7, wherein The acceleration step (d) is, (i) accelerating the data storage disk with the third acceleration from the threshold rotational speed to a second predetermined rotational speed; And (ii) if the second predetermined rotational speed is not equal to the threshold rotational speed, accelerating the data storage disk with one or more next accelerations from the second predetermined rotational speed to the final rotational speed. Including disk rotation speed increase method. A program storage device readable by a computer system that specifically implements programs of instructions executable by the computer system to perform a method for increasing a disk storage speed of a disk drive. How to increase the disk rotation speed, (a) accelerating the data storage disk with a first acceleration from an initial rotational speed to a first predetermined rotational speed; (b) accelerating the data storage disk at a second acceleration from the first predetermined rotational speed to a critical rotational speed; And (c) moving the transducer from a landing zone to a data area on the data storage disk surface when the data storage disk is rotated at the critical rotational speed, The critical rotational speed creates and maintains an air bearing between the transducer and the disk surface. The method of claim 13, The critical rotational speed is the final rotational speed that creates and maintains the air bearing as the transducer moves radially across the disk between the inner and outer diameters. The method of claim 14, The acceleration step (b), (i) accelerating the data storage disk with the second acceleration from the first predetermined rotational speed to a second predetermined rotational speed; And (ii) if the second predetermined rotational speed is not equal to the threshold rotational speed, accelerating the data storage disc with one or more next accelerations from the second predetermined rotational speed to the threshold rotational speed. Program storage device comprising. The method of claim 14, The acceleration step (a) may include accelerating the data storage disk with the first acceleration between an initial time corresponding to the initial rotational speed and a first predetermined time corresponding to the first predetermined rotational speed. Including; And said accelerating step (b) comprises accelerating said data storage disk with said second acceleration between said first predetermined time and a threshold time corresponding to said critical rotational speed. The method of claim 16, And said moving step (c) comprises displacing said transducer from said landing zone at said threshold time. The method of claim 13, The critical rotational speed is an early escape speed that generates the air bearing when the transducer exits the landing zone to access the data area. The method of claim 18, The method, (d) when the transducer is located at an outer diameter of the data storage disk, further comprising accelerating the data storage disk with a third acceleration from the critical rotational speed to a final rotational speed that holds the air bearing. Storage device. The method of claim 19, The acceleration step (a) may include accelerating the data storage disk with the first acceleration between an initial time corresponding to the initial rotational speed and a first predetermined time corresponding to the first predetermined rotational speed. Including; And said accelerating step (b) comprises accelerating said data storage disk with said second acceleration between said first predetermined time and a threshold time corresponding to said critical rotational speed. The method of claim 20, And said moving step (c) comprises displacing said transducer from said landing zone at said threshold time. The method of claim 21, And said accelerating step (d) comprises accelerating said data storage disk with said third acceleration between said threshold time and a final predetermined time corresponding to said final rotational speed. The method of claim 14, The acceleration step (b), (i) accelerating the data storage disk with the second acceleration from the first predetermined rotational speed to a second predetermined rotational speed; And (ii) if the second predetermined rotational speed is not equal to the threshold rotational speed, accelerating the data storage disc with one or more next accelerations from the second predetermined rotational speed to the threshold rotational speed. Program storage device comprising. The method of claim 14, The acceleration step (d) is, (i) accelerating the data storage disk with the third acceleration from the threshold rotational speed to a second predetermined rotational speed; And (ii) if the second predetermined rotational speed is not equal to the threshold rotational speed, accelerating the data storage disk with one or more next accelerations from the second predetermined rotational speed to the final rotational speed. Program storage device comprising. A disk drive comprising a data storage disk rotatably mounted to a base plate and operable to spin at a rotational speed and an actuator arm mounted on the base plate adjacent to the disk. , A transducer attached to the actuator and parked on a landing area on the disk surface, the transducer operable to move over the surface of the disk when the disk reaches a critical rotational speed; And Means for accelerating the data storage disk with multiple accelerations from an initial rotational speed to the critical rotational speed. The method of claim 25, And means for moving the transducer from the landing zone to a data area on the disc at the critical rotational speed. The method of claim 26, The critical rotational speed is the final rotational speed that creates and maintains an air bearing between the transducer and the disk surface as the transducer moves radially across the disk between the inner and outer diameters. The method of claim 26, The critical rotational speed is an early escape speed that creates an air bearing between the transducer and the disk surface when the transducer exits the landing zone and accesses the data area.