Abstract: A (e.g., hard-disk drive (HD)) system supports reader standby mode and/or writer standby mode. For reader standby mode, reader circuitry in the system's preamplifier is transitioned to a low-power mode during write operations. To provide quick transition from write mode to read mode, the reader circuitry is transitioned to pre-read mode before the end of the write operation. For writer standby mode, the preamplifier's writer circuitry is transitioned to a low-power mode during read operations. To provide quick transition from read mode to write mode, the writer circuitry is transitioned to a pre-write mode before the end of the read operation. The availability of a reader standby mode during write operations and a writer standby mode during read operations reduces power consumption as compared to HD systems that leave the reader circuitry in pre-read mode throughout each write operation and the writer circuitry in pre-write mode throughout each read operation.

Abstract: A method for controlling data rate of a tape drive is disclosed. The tape drive is connected to a computer system. The tape drive stores data by dividing the data into multiple codeword quads (CQs). A local memory within the tape drive includes drive to iteratively monitor data rate during write operations. If a number of CQ skips exceeds a pre-defined threshold value, the drive code reduces a maximum allowable data rate of the tape drive.

Abstract: A repeatable read-out (RRO) detector employs one or more digital interpolators to interpolate asynchronous sample values that represent RRO data. The asynchronous sample values are read from a recording medium and generated by an A/D converter at a symbol rate, and the interpolators generate interpolated samples at at least one time in between the asynchronous sample value times. Each interpolated sample corresponding to some phase relative to that of the sample values generated by the A/D converter. The RRO detector receives 1) the asynchronous samples at symbol rate and 2) the interpolated samples to efficiently detect the encoded RRO data. An RRO address mark indicates when detection of encoded RRO data starts, and is employed to select those samples suitable for RRO data detection. Detection of the RRO address mark employs peak detection among filtered asynchronous and interpolated samples. The process of peak detection adjusts the current best phase for sample selection.

Abstract: A method of storing and accessing data from a storage device. The method includes providing a storage that includes a first interface associated with a read-write head configured to read and write data to the storage, the storage further having a second interface associated with a read-only head configured to only read data from the storage, where the first interface includes a hardware selection switch for configuring a first head assembly carrying the read-write head to read data from and write data to the storage, and where the second interface includes a second hardware selection switch for configuring a second head assembly carrying the read-only head to only read data from the storage, and where a first computer connected to the first interface can both read and write data to the storage, while a second computer connected to the second interface can only read data from the storage.

Abstract: A magnetic recording disk drive has disks with identical pre-patterned servo patterns on their front and back surfaces and a servo control system for positioning the read/write heads using the servo signals from the identical servo patterns. The servo sectors on the two disk surfaces form identical patterns of angularly spaced arcuate-shaped lines that extend generally radially across the data tracks. The arcuate-shaped lines on one surface, the front surface, generally replicate the path of the recording head as it is moved across the data tracks by a rotary actuator, so that there is a constant sampling rate of the servo sectors on the front surface regardless of radial position of the head. However, the arcuate-shaped lines on the other surface, the back surface, do not replicate the path of the recording head so the servo sampling rate is not constant but varies with radial position of the head.

Abstract: A patterned disk medium includes a disk-shaped flat substrate including a first surface and a second surface located an opposite side of the first surface. First servo pattern areas including portions provided with magnetic members and portions provided with no magnetic members are provided on the first surface. Second servo pattern areas including portions provided with magnetic members and portions provided with no magnetic members are provided on the second surface. The magnetic members of the first and second servo pattern areas are magnetized in a direction perpendicular to the first and second surfaces. The magnetic polarity of the surfaces of the magnetic members of the second pattern areas differs from that of the surfaces of the magnetic members of the first pattern areas.

Abstract: Methods and apparatus for generating a hard drive write signal are here in disclosed. A disclosed method comprises generating a hard drive write signal on an output of a switch based on an edge of the first control signal and reducing the hard drive write signal based on an edge of a second control signal via a second switch.

Abstract: A method of transferring data of one or more rotatable data storage devices includes but is not limited to rotating the at least one rotatable data storage device; transferring the data between a plurality of stationary data transfer heads and the one or more rotatable data storage devices; and using one or more computer programs to determine which of the plurality of stationary data transfer heads are to be used to transfer a first portion of the data between the plurality of stationary data transfer heads and the one or more rotatable data storage devices and the direction in which the first portion of the data is to be transferred. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present application. Other methods and apparatuses are also disclosed.

Abstract: Embodiments of the invention lower the servo sector's share of each track and ensure that servo sector numbers are reliably determined. According to the embodiment, in the servo sector number (SSA) section of each servo sector, servo sector number information whose bit length (k bits) is shorter than the bit length required to express the servo sector number itself is preliminarily written. The servo sector number of each servo sector is determined by using the servo sector number information in m successive servo sectors, that is, a total of m×k bits of information. Note that they satisfy the m(2m×k?1)?N relation where N denotes the total number of servo sectors per track.

Abstract: A data storage device, method and program product for high data transfer and access rate is disclosed. The data storage device includes a housing wherein at least one data storage disk is rotatably mounted. The housing further includes at least two actuator arm assemblies, each actuator arm assembly carrying a head for reading data from or writing data to the data storage disks. According to the invention the data storage device housing further includes a plurality of device interfaces, one device interface being associated to each of the actuator arm assemblies, and a common hard drive controller. Each of the plurality of device interfaces includes at least one hardware selection switch to configure the respective device interfaces for either read and write mode or read-only mode.

Abstract: Even when both a digital audio signal and an analog audio signal are inputted, a type of inputted digital audio signal is identified, and an internal signal path is automatically switched based on the result of the identification operation and previously set content. A main storage of a host microcomputer 12 stores signal path information indicating a signal path to be selected for each type of digital audio signal inputted from each external AV apparatus. A DIR 3 identifies the type of digital audio signal inputted from a digital input terminal 1. The host microcomputer 12 switches an A/D switching selector 4 and an analog direct/DSP process switching selector 7 respectively so that a signal path corresponding to the type of signal shown in the result of an identification operation of the DIR 3 is selected, based on the signal path information.

Abstract: A conventional magnetic head has a structure, in which a MR element and a recording element are stacked. The influence of a recording magnetic field on the magnetically sensitive portion of a reproduction element is lessened and the performance of the MR element is stabilized. Also, the reliability of the magnetic disk drive using a MR element is enhanced. The magnetic disk drive uses a composite magnet head, which has a plurality of reproduction elements arranged such that the magnetically sensitive layer of a reproduction element of the composite magnetic head does not overlap with the normal direction projection of the recording element, and which lessens the influence of a recording magnetic field on the magnetically sensitive portion of each reproduction element.

Abstract: A recording head drive circuit drives a recording head that records information on a magnetic recording medium. A switching circuit is a H-bridge circuit which includes a plurality of transistors. The switching circuit switches direction of a write current (Iw) flowing in the recording head, in accordance with a conduction state of each transistor. A write current controller controls the write current (Iw) in the recording head. An overshoot control circuit adds an overshoot current (Ios), proportional to the write current (Iw), to the write current (Iw) flowing in the recording head, in a predetermined overshoot time period.

Abstract: The present invention is directed to a method and apparatus for performing best head detection in a disk drive using reference tracks. In one embodiment, a disk drive includes a plurality of disk surfaces. Each disk surface has a read head and a write head associated therewith. A servo track writer is provided for moving each write head and each read head relative to their corresponding disk surfaces. Reference tracks are written onto each of the disk surfaces. The reference track from each disk surface is read by its corresponding read head to determine a best read head. In one embodiment, the servo track writer sweeps each read head across its corresponding reference track as the reference track is being read. In one embodiment, each reference track includes reference track patterns and the best read head is the read head that detects the most patterns.

Abstract: An apparatus for applying write signals including a first write signal and a second write signal to write information to a memory device includes a current directing circuit receiving the write signals and directing a write current to establish a write voltage between first and second write loci in a first or second excursion toward a first or second polarity in response to the first or second write signal. The first and second write loci are coupled with supply locus via an adjacent first or second impedance unit and a first or second switching unit. The first and second switching units are controlled at first and second control loci by the first and second write signals. First and second boost systems are coupled with the first and second control loci for boosting the write voltage toward the first and second polarities during first and second excursions.

Abstract: A method of transferring data of one or more rotatable data storage devices includes but is not limited to rotating the at least one rotatable data storage device; transferring the data between a plurality of stationary data transfer heads and the one or more rotatable data storage devices; and using one or more computer programs to determine which of the plurality of stationary data transfer heads are to be used to transfer a first portion of the data between the plurality of stationary data transfer heads and the one or more rotatable data storage devices and the direction in which the first portion of the data is to be transferred. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present application. Other methods and apparatuses are also disclosed.

Abstract: A method for driving a motor by imposing the current in the motor by means of power current mirrors is presented. This allows driving the motor in current with higher accuracy and lower electrical noise. The Hard Disk Drive application is an example where higher resolution is required for the VCM motor. Furthermore this method reduces the complexity of the system eliminating components and high performance circuits. Moreover this approach reduces the development and manufacturing cost by simplifying the testability and the analysis of the system. The intrinsic elimination of DC offset also takes out the need for the system offset calibration phase and significantly improves on the harmonic distortion of the transfer function. Furthermore this method offers the advantage of faster overall response of the system and higher efficiency.

Abstract: A recording apparatus capable of securely reading out data for causing a head to follow along circular tracks set virtually. Therefore, on-track control along the virtual tracks is possible by the conversion data on the discoid record medium even when, for example, the printed circuit board in a recording apparatus has been replaced.

Abstract: According to one aspect, an exemplary multi-format magneto resistive recording head is provided. The magnetic head includes a first set of data transducers configured transversely across a direction of tape transport, the first set of data transducers associated with a first data format, and a second set of data transducers configured transversely across the direction of tape transport, the second set of data transducers associated with a second data format, wherein the first set of data transducers and the second set of data transducers are separated by a distance along the direction of tape transport. In one example, the magnetic head includes a first raised elongated island positioned transversely across the direction of tape transport, the first island including the first set of data transducers, and a second raised elongated island positioned transversely across the direction of tape transport, the second island including the second set of data transducers.

Abstract: A portable information processing apparatus in provided with a magnetic disk device switchable to a state providing increased resistance to physical shock upon prediction that such a shock is likely. Under predetermined conditions, a second prediction may be issued that such a shock is no longer likely, allowing the magnetic disk device to switch to a normal state of operations. The shock-resistant state of the magnetic disk device can prevent data access and thus inhibit the progress of important process(es). Upon recognition that an important process is being delayed, the condition for issuing the second prediction may be relaxed to more quickly return the magnetic disk device to a normal operating state.

Abstract: A disk drive includes recording media having one or more recording surfaces, one or more transducer heads positionable relative to the recording surfaces by an actuator operating within a head position servo loop, and a data transfer driver. A preamplifier in the data transfer driver includes one or more head interfaces, each head interface for controlling a transducer head for read and write operations, and a mode controller for controlling each head interface based on configuration information for selectively (i) reading data from at least one recording surface, (ii) writing data to at least one recording surface, and (iii) simultaneously reading data (such as a reference pattern) from at least one recording surface and writing data (such as servo patterns) to at least one recording surface.

Abstract: In a substrate structure of a primary disk array apparatus of a disk array system, the primary disk array apparatus contains in one housing at least a plurality of disk drives and a controller substrate with a controller section for controlling the disk drives, and a resource management section that is mounted on the controller substrate of the primary disk array apparatus for managing resources within the housing.

Abstract: A disk drive with switchable power levels for the heaters in the sliders is disclosed. The invention includes a switch for the electrical circuit of each heater which selects between two or more voltages to apply to the power control element and the heater with at least a high and a low voltage option. The heater power control circuit dissipates a certain amount of heat as a part of the control process. By having a low voltage option the disk drive can save power and reduce the amount of heat dissipated by the heater control circuit when high power is not required. The programmable switch is controlled by the drive control system. The high power setting can be used during manufacturing testing or otherwise if higher heater power is needed. The low power setting is used for normal operation or to save power.

Abstract: A multi-head actuator data storage device reads and writes data simultaneously to one of a plurality m of heads, the plurality of m heads mounted on each of n head actuators where the plurality of n head actuators are separated from each other by an angular separation distance of 360/n degrees. The data on the disk is organized into a plurality of logical sectors, each logical sector comprising n ordered physical sectors, where the plurality n of ordered physical sectors is separated by the same angular distance separating the head actuators. During a write operation, each head actuator independently seeks to a unique physical sector, and the order of the physical sectors is communicated to a data de-multiplexer which writes de-multiplexed data to the physical sectors in a predetermined order.

Abstract: A repeatable read-out (RRO) detector employs one or more digital interpolators to interpolate asynchronous sample values that represent RRO data. The asynchronous sample values are read from a recording medium and generated by an A/D converter at a symbol rate, and the interpolators generate interpolated samples at at least one time in between the asynchronous sample value times. Each interpolated sample corresponding to some phase relative to that of the sample values generated by the A/D converter. The RRO detector receives 1) the asynchronous samples at symbol rate and 2) the interpolated samples to efficiently detect the encoded RRO data. An RRO address mark indicates when detection of encoded RRO data starts, and is employed to select those samples suitable for RRO data detection. Detection of the RRO address mark employs peak detection among filtered asynchronous and interpolated samples. The process of peak detection adjusts the current best phase for sample selection.

Abstract: Essentially all of the processing parameters which control processing of a source audio signal to produce an encoded audio signal are stored in an audio processing profile. Multiple audio processing profiles are stored in a processing profile database such that specific combinations of processing parameters can be retrieved and used at a later time. Audio processing profiles are organized according to specific delivery bandwidths such that a sound engineer can quickly and efficiently encode audio signals for each of a number of distinct delivery media. Synchronized A/B switching during playback of various encoded audio signals allows the sound engineer to detect nuances in the sound characteristics of the various encoded audio signals.

Abstract: Track thinning at an IN point of consecutive recording is prevented by doing a head-track one-edge coincidence tracking by using a head of a larger width than the track width. ATF control unit (15) makes a control during reproduction of pre-roll of consecutive recording according to a pilot signal out of the reproduction output from heads (1a, 1c) so that centers of the heads (1a, 1c) may scan the center line of the track. A positioning signal (6g) during the control and a phase of HSW are detected by a detecting circuit (16), and a desired phase having a predetermined advanced amount is set by a desired phase setting unit (18) and stored in a storage unit (19). After this, a tracking method switching control unit (23) switches the tracking method into another by which a control unit (20) controls the difference in phase between the positioning signal (6g) and the HSW to a desired value stored in the storage unit (19).

Abstract: A tape head assembly comprises a transducer head having plural arrays of transducing elements, the transducing elements comprising at least one of write elements and read elements. The tape head assembly further comprises a set of conditioning elements, the conditioning elements comprising at least one of write drivers and read amplifiers. Multiplexing circuitry selectively couples the conditioning elements to one of the plural arrays of transducing elements.

Abstract: In a magnetic disk drive, a writing element and its surrounding area thermally expand due to the heat generated by a write head coil. The transient phenomenon of such thermal expansion may invoke the transient phenomenon of inadequate writing capacity, thereby causing a writing error at an early stage of a write operation. Control is provided which increases/decreases either or both the write current to be applied to a write head and the amount of its overshoot on an individual sector basis during a writing sequence.

Abstract: A disk drive with a dual-stage actuator has a servo control system with two controllers. One controller is a dual-stage controller that simultaneously generates a primary actuator control signal and a secondary actuator control signal, and uses a degraded-stability primary actuator controller design with high low-frequency open-loop gain and a secondary actuator controller design that provides stability and high mid-frequency to high-frequency open-loop gain resulting in increased bandwidth. The other controller is a single-stage controller that generates only a primary actuator control signal and uses a stable VCM-only controller design. The single-stage controller is selected if failure of the secondary actuator is detected.

Abstract: A circuit and method are disclosed for relatively rapidly causing the current flowing through a write head to transition between steady states without generating an appreciable amount of capacitively-coupled noise. Embodiments of the present invention generally provide drive voltage signals to the write head that have no common mode voltage levels during transitions between steady state current levels in the write head. In other words, the drive voltage signals applied to the write head are substantially entirely differential during write head current transitions. In an exemplary embodiment of the present invention, a driver circuit includes switching circuitry connected between the terminals of the write head and reference voltage supplies, such as positive and negative voltage supplies. The driver circuit further includes timing circuitry that generates control signals for controlling the switching circuitry.

Abstract: A write driver circuit for driving a magnetic head applicable to a variety of magnetic heads or magnetic storage media is disclosed. The circuit includes a write current generating section for generating plural types of write current for magnetizing a predetermined area of a magnetic storage medium in a predetermined direction; a switching signal generating section for generating a switching signal for switching among the write currents; a switching section for changing the direction of magnetization through the magnetic head by switching among the write currents based on the switching signal; and an overshoot current generating section for generating an overshoot current for instantaneously increasing the write current when the direction of magnetization is changed by the switching section; wherein the circuit further includes an overshoot current generation signal producing section, and is designed so that the overshoot current is generated based on an overshoot current generation signal produced thereby.

Abstract: A disk drive utilizes a track dependent variable write fault gate for each of the transducers within the drive. By deriving a 3 sigma distribution across the repeatable run out (RRO) and the non-repeatable run out (NRRO), a position error signal (PES) is derived which varies in magnitude across the stroke of the transducers and which has a slope used to derive variable write fault gate thresholds for the tracks associated with each transducer. As the stroke of the transducer moves from the outer diameter (OD) to the inner diameter (ID), the magnitude of the write fault gate thresholds may be decreased relative to the PES, and track density and capacity may increase where PES and write fault gate thresholds are low. The invention thus maintains a constant hard error recovery margin across the stroke.

Abstract: A magnetic head is disposed opposite to a magnetic disk having a first recording area capable of facilitating writing information to the magnetic disk when the surrounding temperature is low, and a second recording area capable of surely holding information written to the magnetic disk when the surrounding temperature is high. Information is written to the first recording area when the surrounding temperature is low and is transferred later to the second recording area.

Abstract: A write driver for use with a magnetic recording head includes a photoconductive switch that is positioned adjacent a magnetic recording head for switching current waveforms. Both light and a DC voltage are applied to the photoconductive switch to switch the applied current waveforms. The write driver further includes means for writing to a storage medium in response to current waveforms switched by the photoconductive switch. The write driver may also include a suspension that supports at least one photoconductive switch, DC conductors for supplying a DC voltage, means for supplying light, and recording head means for writing to a storage medium.

Abstract: A position control system for a magnetic head improves servo tracking characteristics in a low frequency range without impairing the stability of seek operations. The position control system is equipped with two integrators: a first integrator 43 and second integrator 45. The gain K3? of the second integrator 45 is set larger than the gain K3 of the first integrator 43. The first integrator 43 plays the role of offsetting the bias force acting on the magnetic head while the second integrator 45 plays the role of improving the servo tracking characteristics in the low frequency range.

Abstract: A head protection device in a data recording circuit is disclosed in which write-current of a given level that corresponds to a high or low level of coercive force of the magnetic recording portion of a recording medium is provided as an output and supplied to a magnetic head for data recording and reproduction. The data recording circuit comprises an alternate write-current supply portion for alternately providing, by a suitable current switching means, a low write-current corresponding to a low coercivity magnetic head and a high write-current corresponding to a high coercivity magnetic head, a common output portion for providing data to be recorded using a low current or a high current from the alternate write-current supply portion. The low coercivity magnetic head and the high coercivity magnetic head can be at least electrically switched. A current protection portion for a current switching means is provided so as to prevent generation of high write-current at the alternate write-current supply portion.

Abstract: There is provided a video cassette recorder comprising a delay element (1), a switching unit (2) for switching an output of the delay element (1), a logic unit (3) for controlling the switching unit (2), and a skew detection unit (4) for detecting a skew, wherein the delay element (1) shares a delay element used for vertical emphasis/vertical de-emphasis and for a comb line filter during a special replay. The video cassette recorder thus provides a fast-forwarding replay image, a rewinding replay image and a still image with improved skew distortion from a tape recorded in a long recording mode providing quintuple the recording time of a standard mode. This realizes an excellent special replay image at low cost without requiring an expensive circuit such as a TBC and the like.

Abstract: A system and method enable boosting a bias applied to a load so as to facilitate reversing the direction of the bias applied relative to the load. The amount of boosting provided to facilitate reversing the bias polarity, depends on a substantially fixed boost voltage, which can be programmable. Thus, by setting the boost voltage to a predetermined voltage improved performance can be achieved, including, for example, improving the rise and/or fall times of bias current applied to an inductive load.

Abstract: In an apparatus for reproducing recorded signal and the like of this invention, two reproducing heads are provided for a single track with their set positions being deviated in the track width direction. A signal selecting unit discriminates are producing head whose tracing condition of a target track is appropriate based on an error correction result of a C1 correcting unit and output levels of reproducing heads. A signal obtained by the discriminated reproducing head is supplied to a C2 correcting unit to generate an output signal. Consequently, an off track allowance is increased as compared with a case where the target track is traced with a single reproducing head. At the time of special reproducing operation or even if a narrow track pitch system is adopted, a recorded signal is reproducible properly.

Abstract: A disk drive which incorporates separate actuators for each recording head so as to only place required recording heads over the recording media of multiple surface hard disk drives. The reduction in recording heads that are placed over the recording media reduces drag on the rotating disk holding the recording media and thereby reduces the power consumption. Reducing the number of recording heads over the recording media also reduces damage to the recording media surfaces in the event of a physical shock to the drive since inactive transducer heads are not in a position to damage the recording media.

Abstract: A hard disk drive (HDD) for detecting and reading a signal written on a hard disk using a head. The hard disk drive includes: a plurality of head disk assemblies each having at least one controller, a plurality of disks for storing magnetized data and a plurality of heads for writing and reading data to and from the disks; a main printed circuit board physically being separated from each head disk assembly, for controlling reading/writing of data by the heads; and connectors for electrically connecting the main printed circuit board with each head disk assembly, wherein the main printed circuit board includes a setting unit for setting information about the disks and heads contained in each head disk assembly, and a switch unit for selecting a disk and a head of one head disk assembly according to the information set by the setting unit and assessing the selected disk and head via the corresponding connector when intended to access a predetermined disk and head of one of the head disk assemblies.

Abstract: Disclosed is a head system including a plurality of recording heads for azimuth recording. The system includes a first recording head having a plurality of magnetic gaps having a first azimuth angle, and a second recording head having a plurality of magnetic gaps having a second azimuth angle different from the first azimuth angle. After first magnetization patterns are formed on a recording medium by the first recording head, second magnetization patterns are formed by overwriting side edge portions in the formation direction of the first magnetization patterns by the second recording head. This makes it possible to prevent worsening of the accuracy of magnetization pattern width due to a relative height stagger (offset) between the heads, to thereby enhance the accuracy of the magnetization pattern width, and to achieve high-density recording.

Abstract: A method and a device enters a test mode in a floppy disk drive integrated circuit. The method and device includes a monitoring circuit and an integrated circuit having a selecting circuit. The selecting circuit selects a test-mode when a test mode command is received and a steady state voltage level is reached in a predetermined time period.

Abstract: An apparatus for use in applying write signals including a first and second write signal for a write head to write information to a memory device includes: (a) a current director for receiving the write signals and directing a write current to establish a write voltage across the write head in a first excursion in response to the first write signal and in a second excursion in response to the second write signal; the first and second excursions occurring about a common mode voltage; (b) a voltage drop unit coupled with a supply voltage and the current director at a connection locus for establishing the common mode voltage substantially equal with the supply voltage less a voltage drop; and (c) a switching unit coupled with the voltage drop unit and the connection locus and cooperating with the voltage drop unit to vary the voltage drop.

Abstract: An apparatus for use in applying write signals for driving a write head to effect writing information to a memory device; the write signals including a first write signal and a second write signal; includes: (a) a directing circuit receiving the write signals, directing a current to establish a voltage across the write head in a first excursion toward a first polarity in response to the first write signal and directing the current to establish the voltage across the write head in a second excursion toward a second polarity substantially opposite the first polarity in response to the second write signal; (b) a first boost system coupled with the directing circuit and boosting the write voltage toward the first polarity during the first excursion; and (c) a second boost system coupled with the directing circuit and boosting the write voltage toward the second polarity during the second excursion.

Abstract: A playback error associated with overwriting on a narrow-width track is prevented from occurring in the overwritten portion. A signal generator (11) generates a signal of a predetermined data pattern that stabilizes the operation of a synchronizing pulse generator of a playback system (shown in a separate figure). A timing generator (4) switches over a switch (12) to the output of the signal generator (11), at least a period of time equivalent to writing of one track before the main signal is input. When a signal of the predetermined data pattern from the signal generator (11) has been output, the timing generator (4) switches over the switch (12) to the main signal. The playback system includes a circuit which discriminates between the predetermined data pattern and the main signal data from a playback signal generated by playing back a record on a magnetic tape (T).

Abstract: A switch for an electronic device includes a main printed circuit board having a contact point mode pattern at an upper surface thereof; and a rotor rotatively installed on the main printed circuit board with one or more brushes mounted therein so as to be connected to the contact point mode pattern. The rotor may be engaged to a moving member of the electronic device so that the rotor is rotated to different orientations depending on the operational mode of the electronic device. Because the rotor is directly installed on the main printed circuit board, the number of construction components is reduced, and the product can be more compact.

Abstract: A method of defining storage format in a data storage device having a plurality of storage media and a plurality of corresponding data transducer heads, each transducer head for recording on and playback of information from a corresponding storage medium. A storage format is defined in at least one region on each storage medium, wherein each region includes a plurality of concentric tracks for recording on and playback of information. The method includes: moving each storage medium with respect to the corresponding transducer head and reading data from each storage medium with the corresponding transducer head; measuring a record/playback performance capability of each transducer head; selecting a group of track densities, one track density for each region on a storage medium, based on the measured record/playback performance capability of the corresponding transducer head.

Abstract: In a magnetic disk storage apparatus, when a drive current of the voice coil motor is small, the head drive control circuit executes the linear drive mode under which the voice coil motor is driven in a linear control manner, whereas when the drive current is large, the head drive control circuit executes the pulse drive mode under which the voice coil motor is driven in a pulse width control manner. Both modes are carried out by employing a commonly-used output amplifier that is arranged as a push-pull type output circuit made of both a push-driving output transistor and a pull-driving output transistor. An operation mode of this output amplifier is set to an AB-class operation during the linear drive mode, whereas the operation mode of this output amplifier is set to a B-class operation during the pulse drive mode.