Abstract: A card insulator is formed with slits that conform to height changes required by the components mounted to a card. The insulative sheet has simple linear slits that extend completely through the sheet and allow the insulator to deform with simple linear bends when contacted by the tall components mounted to the card. The linear bends allow the surface of the deformed insulator to be flexible without budding the insulator and without bowing the card.

Abstract: A perpendicular magnetic recording disk has a soft magnetic underlayer (SUL) that has high corrosion resistance as well as high moment. The material of the SUL is an alloy comprising Co, Fe, X, and Y; where X is Ta or Nb, Y is Zr or Hf, and the combined amount of X and Y present in the alloy is between about 10 and 20 atomic percent. The atomic ratio of Co to Fe in the alloy is between about 90:10 to 10:90, preferably between about 25:75 and 35:65. The SUL may be a single-layer SUL or a multilayer SUL formed of multiple soft magnetic layers separated by an interlayer film or films.

Abstract: A perpendicular magnetic recording medium at least comprises a perpendicular magnetic recording layer and a backing layer backing the perpendicular magnetic recording layer. The backing layer has an in-plane magnetization and is formed of a ferrimagnetic material having a compensation temperature in the vicinity of a recording/reproducing temperature in which reproducing of magnetic information is made from the perpendicular magnetic recording layer. A magnetic storage apparatus for recording and reproducing magnetic information using the perpendicular magnetic recording medium is also disclosed.

Abstract: Provided are a bit patterned medium having a super-track, a method of tracking a track of the bit patterned medium, a head appropriate for the bit patterned medium, and an information recording/reproducing apparatus including the bit patterned medium and the head. The bit patterned medium includes a substrate, and a recording layer comprised of a plurality of bit cells which are formed on the substrate by being separated from each other, along a plurality of tracks. Each of the plurality of tracks includes a super-track comprised of a plurality of sub-tracks. Bit cells formed on a sub-track from among the plurality of sub-tracks in the super-track are disposed so as to deviate from bit cells formed on another sub-track from among the plurality of sub-tracks in the super-track. A track ID (identification) for recognizing the super-track, and a servo burst generating a position error signal when a head tracks the super-track, are arranged in an area of each of the plurality of tracks.

Abstract: A magnetic recording medium with excellent signal characteristics is provided in which the stability of recorded information is ensured even when recording is performed in high density or even when magnetic recording and reproduction are performed while the temperature of a recording film is increased by irradiation with light. The present invention provides a magneto-optical recording medium comprising at least a memory layer on a disk substrate, in which the memory layer is separated into magnetic grains to form magnetically isolated recorded domains, or in which a fine structure is formed by an aggregate of mutually isolated magnetic grains in the memory layer, and the memory layer has a large specific resistance. A production method thereof is also provided.

Abstract: A magnetic recording disk drive has a disk with pre-patterned nondata servo sectors extending generally radially across the data tracks. The disk may be a patterned-media disk with both pre-patterned data islands and pre-patterned nondata servo sectors. The servo sectors include a synchronization pattern of generally radially directed discrete magnetized marks, and first and second position error signal (PES) fields of generally radially directed discrete magnetized stripes. Each stripe in each of the two fields comprises a plurality of radially spaced discrete servo islands, each island having a radial height of approximately Tp, where Tp is the radial spacing of the track centerlines. In each field, the servo islands in alternating stripes in the along-the-track direction are shifted radially by approximately Tp. In the first PES field, the islands are centered at the midline between two adjacent track centerlines, and in the second PES field the islands are centered at a track centerline.

Abstract: Recording media comprises multiple first and second patterned media islands sequentially placed at different first and second radii along a length of a recording track. A recording head sequentially accesses the first and second islands as the head moves along a length of the recording track. Circumferential spacings between sequential first and second islands along the length of the track vary as a skew function of a track radius.

Abstract: A laminated film structure is disclosed comprising multiple ferromagnetic layers achieving improved data recording performance. A non-magnetic spacer layer is disposed between an upper ferromagnetic layer and an antiferromagnetic coupled (AFC) structure. The AFC structure is comprised of a ferromagnetic layer and an antiferromagnetic slave layer. The ferromagnetic layer in the AFC structure, referred to as lower ferromagnetic layer, may contain tantalum to promote chromium segregation at the grain boundaries to achieve magnetic decoupling of the grains with relatively thin boundaries, improving medium signal-to-noise ratio while maintaining good thermal stability of the medium. In some embodiments, the interlayer is a five-element alloy such as a CoCrPtBTa alloy.

Abstract: Embodiments of the present invention provide a recording disk capable of curtailing the amount of servo data to be stored thereon, and a disk drive. According to one embodiment, servo data area sets each of a first servo data area and plural second servo data areas arranged in that order in a read direction HR are arranged successively on each of tracks of a magnetic disk. Stored in a second sector data section included in the second servo data area is data representing a distance in the read direction HR from the position of the first servo data area to that of the same second servo data area. The amount of data stored in the second sector data section is less than that of data stored in a first sector data section included in the first servo data area.

Abstract: Embodiments of the present invention help to provide a discrete track medium for realizing a high track density in a low price by adopting a configuration, in which filling of a non-magnetic material into a guard band portion and smoothing processing of a medium surface are not required. According to one embodiment, a perpendicular magnetic recording medium, on the non-magnetic substrate, includes at least: a soft magnetic underlayer; a first recording layer including a crystal grain having a magnetic property and a non-magnetic grain boundary having an oxide, as a main component, surrounding the crystal grain; a second recording layer containing a ferromagnetic metal as a main component and not containing an oxide; and at least one non-magnetic layer provided between the first recording layer and the second recording layer.

Abstract: An apparatus comprises a storage medium having a surface coated with a layer of a first solid lubricant, and a head separated from the storage medium by an air film, the head having an air bearing surface, wherein at least a portion of the air bearing surface is coated with a layer of a second solid lubricant.

Abstract: On a magnetic recording medium, a servo pattern is formed in a servo pattern region on at least one surface of a substrate by a concave/convex pattern including a convex part, at least protruding end part of which is formed of magnetic material, and a concave part. The servo pattern region includes an address pattern region and a burst pattern region, wherein the convex part is formed in the servo pattern region so that a larger of an inscribed circle with a largest diameter out of inscribed circles on an open surface of the concave part formed in the address pattern region and an inscribed circle with a largest diameter out of inscribed circles on an open surface of the concave part formed in the burst pattern region is an inscribed circle with a largest diameter out of inscribed circles on an open surface of the concave part formed in the servo pattern region.

Abstract: The magnetic recording medium includes: a recording layer formed over a substrate in a predetermined concavo-convex pattern, convex portions of the concavo-convex pattern constituting recording elements; a filler underlayer film formed on the bottoms of concave portions of the concavo-convex pattern; and a DLC filler formed on the filler underlayer film in contact with the filler underlayer film so as to fill the concave portions. The filler underlayer film is made of a material selected from the group consisting of a Si-containing material, a Ge-containing material, and a carbide material containing one or more metal elements selected from Ti, Ta, Nb, Mo, Zr, Cr, W, V, and Hf.

Abstract: A patterned disk for a hard disk drive. The patterned disk includes a magnetic material over a substrate. The magnetic material includes a plurality of grooves. The grooves are filled with a lubricant that is hardened with UV exposure or some other hardening process. The lubricant provides a protective cover for the magnetic material exposed by the grooves. The use of lubricants in the fabrication of disks is known, thus the process does not introduce a process step that requires special equipment and/or process development.

Abstract: A discrete track medium and a bit patterned medium with a high SNR are manufactured at low cost. A seed layer and a recoding layer are formed on a bottom surface and a side wall of a groove portion, which is formed between non-magnetic projected structures artificially patterned. Then, the recording layer on the projected portion is removed.

Abstract: A patterned recording media comprises a segment and a null pattern formed in the segment. The segment comprises first and second rows of discrete magnetic elements separated by a non-magnetic material, and a row of non-magnetic material positioned between the first and second rows. The null pattern comprises consecutive groups of the discrete magnetic elements in the first and second rows of the segment. Each group in the first row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the first row. Each group in the second row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the second row.

Abstract: Provided are a magnetic head, a magnetic recording medium, and a magnetic recording apparatus using the magnetic head and the magnetic recording medium. The magnetic head is used for magnetically recording data on a magnetic recording medium and includes a main pole; a return-yoke forming a magnetic path along with the main pole; a coil for inducing a magnetic field to emit a magnetic field for magnetic recording through an end tip of the main pole near a magnetic recording medium; and an insulating layer for electrically insulating the main pole from the return-yoke. The main pole is electrically connected to an external device and generates an electric field for assisting magnetic recording along the magnetic field for magnetic recording. In this structure, the coercive force of a magnetic recording layer can be reduced during magnetic recording so that data can be recorded at high density.

Abstract: Provided is a bit patterned medium including bridges which induce exchange coupling between adjacent bits in order to reduce a switching field difference resulting from different magnetization directions of bits. The bridges and the bits are integrally formed with each other. The bits are locally connected by the bridges. A magnetostatic force for each bit is reduced due to an exchange coupling between adjacent bits, thereby reducing a switching field distribution of the bits.

Abstract: A method for producing a magnetic recording medium, including depositing an imprint resist layer on a magnetic layer containing a ferromagnetic material and a first non-magnetic material, on a substrate, transferring a concavo-convex pattern onto the imprint resist layer by pressing against the imprint resist layer an imprint mold structure having convex portions so as to have concavo-convex portions, forming magnetic pattern portions corresponding to the concavo-convex pattern by etching the magnetic layer using the imprint resist layer as a mask, and forming non-magnetic pattern portions by embedding a second non-magnetic material in concave portions, wherein the magnetic layer is etched so as to remove the ferromagnetic material in the magnetic layer, and leave 5% by mass or more of the first non-magnetic material in each concave portion relative to the total mass of the first non-magnetic material in each region corresponding to the concave portions to be formed.

Abstract: Embodiments of the present invention provide a perpendicular magnetic recording media having excellent resolution, signal to noise ratio (S/N), and a small adjacent track erasure. According to one embodiment, underlayers for controlling the orientation and segregation of a magnetic layer, a magnetic layer including an oxide and an alloy of magnetic materials mainly composed of Co, Cr, and Pt, and a ferromagnetic-metal layer which does not contain oxygen, are formed over a substrate. The magnetic layer has at least two layers including ferromagnetic grains and oxides, a first magnetic layer, which is the part of the magnetic layer closer to the substrate, has grain boundaries mainly composed of Cr oxide and at least one oxide selected from Si, Ti, Nb, and Ta, and grain boundaries of a second magnetic layer at the ferromagnetic-metal layer side includes at least one oxide selected from Si, Ti, Nb, and Ta in which Cr oxide is less than the first magnetic layer.

Abstract: A magnetic recording medium in which a recording layer is formed in a predetermined concavo-convex pattern and recording and reproducing apparatus comprising the magnetic recording medium are disclosed. The magnetic recording medium has a high areal density and high reliability since the occurrence of a crash of a magnetic head is suppressed. The magnetic recording medium comprises a recording layer formed over a substrate in a predetermined concavo-convex pattern to form recording elements as a convex portion of the concavo-convex pattern and a non-magnetic filler element filled in a concave portion between the recording elements. In this configuration, the top surface of the filler element is formed in a shape partially recessed toward the substrate side to form a groove having a width smaller than the width of the concave portion on the surface of the magnetic recording medium.

Abstract: The recording layer (to-be-etched layer), a main mask layer, and a sub mask layer are formed in this order over a substrate, and the sub mask layer is processed into a predetermined concavo-convex pattern. Next, parts of the main mask layer under the concave portions are removed by reactive ion etching using oxygen or ozone as the reactive gas. Parts of the recording layer under the concave portions are also removed by dry etching, whereby the recording layer is shaped into the concavo-convex pattern. The main mask layer is chiefly made of carbon. The sub mask layer is made of a material having an etching rate lower than that of carbon with respect to the reactive ion etching in the step of processing the main mask layer.

Abstract: A device comprises a first storage medium, input/output architecture, a second storage medium, and a processor. The processor is arranged, in response to a request to access a file stored on the first storage medium, to recall the file from the first storage medium at substantially the data rate of the file, to transmit a first portion of the file, and to store a second portion of the file in the second storage medium.

Abstract: An imprint mold structure of the present invention is for producing a magnetic recording medium having servo areas each of which has a preamble area where servo data for synchronization with a clock cycle is recorded, and data areas where user data is written, and contains a first convexo-concave pattern corresponding to the servo areas and a second convexo-concave pattern corresponding to the data areas, wherein a ratio L/S of a width “L” in the circumferential direction of a convex portion corresponding to a non-magnetic portion formed in the preamble area to a width “S” in the circumferential direction of a concave portion corresponding to a magnetic portion formed in the preamble area varies depending on a distance “R” from a center of the imprint mold structure to a center of a pattern unit composed of the convex portion and the concave portion in the first convexo-concave pattern.

Abstract: There is proposed a nonvolatile information recording and reproducing device with low power consumption and high thermal stability. The information recording and reproducing apparatus according to an aspect of the present invention includes a recording layer and a unit for recording information by applying a voltage to the recording layer to generate a state change in the recording layer. The recording layer being configured to include at least a first compound having a hollandite structure.

Abstract: A bearing unit includes a shaft, a tubular bearing member, a planar plate fixed to a lower side of the bearing member and a lubricant filled between the shaft and an inner circumferential surface of the bearing member. In the bearing member, an inner circumferential wall portion is axially downwardly protruding from a lower surface of the bearing member and has a first surface contacting with and extending in a parallel with an upper surface of the plate and a second surface axially spaced apart from the upper surface of the plate. An outer circumferential wall portion is positioned radially outwardly of the second surface. The plate is fixed to the outer circumferential wall portion of the bearing member, and a radial inner side of the inner circumferential wall portion communicates with the outer circumferential wall portion through a gap formed between the second surface and the slate.

Abstract: There is disclosed a magnetic disk apparatus including a magnetic disk and a magnetic head for recording data onto the magnetic disk or reading data from the magnetic disk. The magnetic disk includes a retracting part for loading the magnetic head on a surface of the magnetic disk or unloading the magnetic head from the surface of the magnetic disk. The magnetic head includes a protruding part provided at a tip part thereof. The retracting part includes an engaging part extending above the magnetic disk and having a slope part, and a driving part configured to move the engaging part in a direction orthogonal to the surface of the magnetic disk in a state where the protruding part contacts the slope part when unloading the magnetic head from the surface of the magnetic disk.

Abstract: Provided is a surface-treated substrate in which the roughness of the surface of the substrate is controlled. The surface-treated substrate can form a magnetic recording medium in which head flying stability is maintained and which has a magnetic film that can achieve high recording densities. Also provided is a method for roughening the surface of the substrate. More specifically, provided is a surface-treated silicon substrate for a magnetic recording medium in which a surface used for forming a recording layer has 40 to 1000 protrusions per 1 ?m2 with a maximum height of 10 nm or less and an average roughness of 0.3 to 2.0 nm, and in which there are no defects or spots on any of the surface. Furthermore, provided is a method for manufacturing the surface-treated silicon substrate for the magnetic recording medium, comprising a step of etching a surface of a silicon substrate, wherein ultrasound is applied to the surface of the silicon substrate with the substrate shaken or rotated.

Abstract: On an information recording medium, a data track pattern and a servo pattern composed of a concave/convex pattern including a plurality of convex parts are formed on at least one surface side of a substrate and respective concave parts in the concave/convex pattern are filled with non-magnetic material. The concave/convex pattern that constructs the servo pattern is divided into a plurality of ring-shaped regions that are concentric with the data track pattern and has a unit convex part length along a direction of rotation of the substrate set in each ring-shaped region so that a value produced by dividing an average length of the unit convex part length in each ring-shaped region by a distance from a center of the data track pattern to the ring-shaped region decreases from ring-shaped regions in an inner periphery to ring-shaped regions in an outer periphery.

Abstract: In a magnetic recording medium including a servo pattern region having a servo pattern formed of a concave/convex pattern having convex portions and concave portions and a data recording region, the region having a data track pattern, the concave portions are formed in an address pattern region of the servo pattern region such that the maximum lengths, which are located in the respective same radius regions of the respective lengths along the rotating direction of a substrate of the projecting end surfaces of the convex portions constituting the concave/convex pattern are set to first lengths that are double the minimum lengths along the rotating direction of the projecting end surfaces of the convex portions in the respective same radius regions. With this arrangement, the magnetic recording medium can securely read a magnetic signal and has a servo pattern having excellent surface smoothness.

Abstract: A magnetic recording system includes a patterned medium comprised of land areas and trough areas, a write element which writes the data to the patterned medium, and a read element which reads the data from the patterned medium and servo information from the troughs. The land areas store data and the trough areas inhibit storage of data. The read element is wider than the write element.

Abstract: A glass substrate for a magnetic recording medium is formed to have a disc shape and includes ridge shaped textures 13 extending along concentric circles on a main surface. When measuring a 10 ?m square range with an atomic force microscope, the textures have a width W that is between 10 and 200 nm. The textures have a height H that is between 2 and 10 nm. Further, the textures have a ratio (Rp/RMs) of a maximum mountain height with respect to a root mean square roughness that is less than or equal to 15. The textures include high frequency components superimposed on the low frequency components. It is preferable that the textures of the high frequency components have a width W? that is between 0.1 and 20 nm, and the textures of the high frequency components have a height H? that is between 0.1 and 1 nm.

Abstract: A perfluoropolyether hard disk lubricant having a UV curable functional end group that may be UV cured at a rapid rate with a Xenon excimer lamp. The perfluoropolyether preferably has at least one UV curable functional end group. In one embodiment, the UV curable end group comprises an acrylate.

Abstract: A tilted magnetic recording medium comprises a layer of magnetic material having a magnetic easy axis defined by tilted alignment of a particular crystalline phase of the magnetic material. A film of (101) and (011) textured L10 phase of a tetragonal crystalline magnetic material has crystalline c-axes oriented 45° to the medium surface normal. The L10 crystalline magnetic alloy comprises a first element selected from the group consisting of Co and Fe, and a second element selected from the group consisting of Pt and Pd. A seedlayer comprising a bcc or B2 crystal structure with a natural texture of (110) creates interfacial stress with the magnetic layer, giving rise to a pure (101) and (011) textured L10 crystalline film. A textured underlying surface facilitates preferential formation of the seedlayer and subsequent growth of the magnetic material to achieve tilted magnetic directions perpendicular to the recording tracks.

Abstract: The present invention provides a magnetic recording medium having superior startup operation and durability as well as satisfactory surface lubricity. The present invention relates to a production process of a magnetic recording medium in which at least a magnetic layer, a protective film layer and a lubricant layer are sequentially laminated on a non-magnetic substrate, wherein the protective film layer is surface treated using a gas activated by plasma generated at a pressure in the vicinity of atmospheric pressure. The present invention also relates to a magnetic recording medium produced according to the aforementioned production process.

Abstract: A magnetic recording medium includes a disk substrate and a magnetic recording layer formed on one surface or both surfaces of the disk substrate. The magnetic recording layer includes at least one pattern area forming a plurality of data tracks in which a position for magnetic recording is patterned with a magnetic body and at least one continuous area formed of a continuous magnetic body, and at least a part of a servo pattern for following the data track is recorded in the continuous area. A method of recording a servo pattern on a magnetic recording medium includes determining a center position of the data track and a start position of the continuous area and recording a servo pattern for following the data track in the continuous area with respect to center position of the data track and the start position of the continuous area.

Abstract: A ferroelectric disk is disclosed including disk surfaces and an electrode coupling formed on at least one of the disk surfaces and electrically coupled to an electrode sheet covered by a probe surface. A slider is disclosed including a resistive probe and an electrical coupling. A head gimbal assembly, head stack assembly and ferroelectric disk drive are disclosed including the slider. The ferroelectric disk drive is disclosed including at least one of the ferroelectric disks. Access operations for a track on the disk surface of a ferroelectric disk are disclosed.

Abstract: A magnetic medium for perpendicular magnetic data recording. The magnetic medium has a magnetically soft under-layer and a magnetically harder top layer. The magnetic under-layer has a magnetic anisotropy that is oriented in a radial direction relative to the magnetic medium. The magnetic anisotropy is induced by an anisotropic texture on the surface of the magnetic underlayer.

Abstract: A method of copy protecting optical discs uses the differences in capability between the encoder associated with a laser beam recorder and that in currently available CD writers. Digital sum value (DSV) is a property of the encoded data on CDs and an encoder, which controls a laser beam recorder may be able to choose a pattern of merge bits which result in the overall DSV having optimal properties. During mastering of a CD, data patterns are added to the disc to provide an authenticating signature. These data patterns are chosen to cause DSV problems. Currently available CD writers have been found to have difficulty writing an authenticating signature of the type described without producing a resulting CD which has severe readability problems. Thus, the copy disc written by the CD writer will result in a CD reader returning corrupted data or information signalling a read error.

Abstract: The present invention provides a magnetic disk in a discrete track medium and a patterned medium, which prevents the loss of the magnetically recorded data when a head of a magnetic disk device contacts the magnetic disk, and a manufacturing method thereof. A magnetic disk has a protrusion as a non-magnetic member formed on a disk surface to prevent a head from being in contact with a recording section. When the protrusion formed in a disk substrate collides against the head, the protrusion 7 does not collapse, and accordingly, the recording layer is not damaged. Alternatively, concave and convex portions are formed on the substrate surface to use the convex portion as the protrusion.

Abstract: A method of forming a conductive pattern can form a conductive pattern where the aspect ratio of the height to the width is high with favorable electrical connectivity.

Abstract: With a magnetic recording medium, servo pits have to be recorded one disk at a time, which is a problem in that it takes more time and is more expensive. In view of this, with the present invention, at least one signal region whose surface roughness is different from that of other than the signal region is formed on the substrate of a magnetic recording medium comprising a recording layer on a substrate, or on an under layer formed on a substrate.

Abstract: Embodiments in accordance with the present invention provide a perpendicular magnetic recording medium which is easy to record, offers superior thermal stability of recording magnetization, and allows high-density recording. In one embodiment, a perpendicular magnetic layer with controlled magnetic properties is used as a magnetic storage layer of a perpendicular magnetic recording medium, the magnetic properties having been controlled such that an indicator ?hsw [%] of the dispersion of magnetization switching fields in the perpendicular magnetic layer and an indicator Dn [nm] of the intensity of exchange interactions, in film surface directions, in the perpendicular magnetic layer satisfy inequalities ?hsw/27+Dn/90<1, and Dn>20. The indicators can be measured using a magnetometer.

Abstract: A magnetic recording medium includes: a substrate; a recording layer that is formed on the substrate to have a grooved pattern; and a protection layer formed on the recording layer to fill in the grooved pattern, wherein the recording layer is defined to have a servo portion that retains servo data and a recording track portion that retains recording data, and wherein a first film thickness of the protection layer at the servo portion is larger than a second film thickness of the protection layer at the recording track portion by a thickness that is in a range from 1 nm to 10 nm.

Abstract: A fluid dynamic bearing mechanism that can ensure bearing rigidity, reduce shaft loss torque, reduce power consumption, stabilize axial rotation, and improve rotational accuracy is disclosed. The fluid dynamic bearing mechanism being suitable for use in a hard disk drive. In the fluid dynamic bearing mechanism (equipped with a bearing case, endplate, and shaft) a cylindrical hole of the bearing case is changed to a stepped cylindrical hole that has a large diameter part and a small diameter part. The shaft is changed to a stepped shaft that has a large diameter part and a small diameter part. On the outer circumference of either the large diameter part of the stepped cylindrical hole, or the large diameter part of the stepped shaft, a first dynamic pressure groove is be formed. On the outer circumference of either the small diameter part of the stopped cylindrical hole or the small diameter part of the stepped shaft, a second dynamic pressure groove is being formed.

Abstract: The invention provides an ink jet recording head in which an element substrate provided in a head unit and constituted of plural drive elements is driven to discharge ink droplets from plural nozzles. In the ink jet recording head, the head unit has a substantially parallelogram shape, and plural head units are connected in a row to form a head bar.

Abstract: A thermally assisted magnetic recording system is provided to achieve excellent thermal resistance and low noise. In one embodiment, a magnetic recording medium is used, in which the magnetic intergrain exchange coupling is large to let the magnetization be thermally stable by coupling the magnetic grains constituting the recording layer at room temperature (the temperature maintaining the magnetization) and reduced by heating during recording to let the recording magnetization transition slope become steep. Parameter A normalizing the slope around the coercivity of the MH-loop of the medium is 1.5?A<6.0 at room temperature, and it becomes approximately 1.0 with heating.

Abstract: A composite disk-clamp assembly including a clamp or spacer of a resilient material coupled to a disk by injection molded plastic so that the clamp forms an integral portion of the disk itself.

Abstract: A magnetic recording disk in a disk drive has identical pre-patterned servo patterns on its front and back surfaces. The servo patterns on each disk surface are pre-patterned with a single master template, resulting in the identical pattern on each disk surface. The servo sectors on the two disk surfaces can form identical patterns of angularly spaced arcuate-shaped lines or straight lines that extend radially across the data tracks. However, because the lines on at least one of the disk surfaces do not replicate the path of the recording head, the sampling rate of the servo sectors on that surface is not constant but varies with radial position of the head. To accommodate this, the disk drive's servo control system calculates a timing adjustment from an estimate of the radial position of the head and uses this timing adjustment to adjust the time to open a time window to allow detection of the servo sectors.

Abstract: A storage disk for a hard disk drive includes a homogeneously-formed body region, a first side region and a second side region. The body region includes a first body side and a second body side opposite the first body side. The first side region is secured to the first body side and the second side region is secured to the second body side. In one embodiment, the first side region is adapted to store data and the second side region is not adapted to store data. The first side region includes a plurality of layers formed from different materials relative to one another. The first side region has a first density that is different than a second density of the second side region. In one embodiment, the first side region has a mass that is different than a mass of the second side region. In an alternative embodiment, the first side region has a thickness that is different than a thickness of the second side region.