Did You Know...
...that when IBM conducted a market study of Chester Carlson's invention in 1959, the company concluded that it would take only 5000 units of his new product to saturate the market? IBM therefore declined to be part of the new product introduction. Too bad for IBM. Carlson's invention was the xerography process, and his new product was the beginning of the Xerox Corporation. It is estimated that every day, worldwide, 3,000,000,000 copies are made!!
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| Number | Title | Issue Date |
| 7518821 | Hard disk drive Stable recording and reproduction of data onto and from a recording medium that requires precise tracking is provided by using a simple head tracking mechanism. In a hard disk drive (200), a piece of sector data to be written or read is pre-associated with a ... | 04/14/2009 |
| 7319652 | Controlling optical pickup of optical disk drive by detecting change of sampling signals taken from a motor drive signal A drive current or a drive voltage is controlled corresponding to change of load by sampling the drive current or drive voltage of a motor to move an optical pickup and then detecting change of the sampling signal as change of the optical pickup when it is moved. Mo... | 01/15/2008 |
| 7239108 | Method for stepper motor position referencing A method for referencing a polyphase stepper motor by monitoring the current step response in at least one driven phase is presented. The coil current step response is compared to past step responses in order to determine when an increase in or maximum load is prese... | 07/03/2007 |
| 7221985 | On-screen calibration system and operating method thereof An on-screen calibration system for disc drives and the operating method thereof. The calibration system includes an autocollimator detecting the inclined angle of the stage of a disc drive. A control module is connected to the on-screen display module and a bar cod... | 05/22/2007 |
| 7184480 | Digital PWM generator A digital PWM circuit is provided. One exemplary circuit includes a binary counter, an n-bit DAC and a comparator. The binary counter generates a plurality of binary signals in increasing and/or decreasing value. The DAC circuit generates ramp signals composed of a ... | 02/27/2007 |
| 7023653 | Floppy disk apparatus A floppy disk apparatus improves power efficiency and quietness by commencing rotation of a stepping motor in a smooth fashion. The floppy disk apparatus includes an interface control circuit that outputs, in accordance with an instruction from a host apparatus, a f... | 04/04/2006 |
| 6954414 | Controlling optical pickup of optical disk drive by detecting change of sampling signals taken from a motor drive signal A drive current or a drive voltage is controlled corresponding to change of load by sampling the drive current or drive voltage of a motor to move an optical pickup and then detecting change of the sampling signal as change of the optical pickup when it is moved. Mo... | 10/11/2005 |
| 6950262 | Flexible disk drive control method capable of preventing a seek error from occurring In a flexible disk drive for driving a flexible disk inserted in the flexible disk drive, when a power supply is turned on and when the flexible disk is not inserted in the flexible disk drive, a seek operation is inhibited and a track 00 signal is supplied to a hos... | 09/27/2005 |
| 6870701 | Motor driving device and disk device A motor driving device is provided with a motor and a motor driver circuit for controlling the motor. The motor driver circuit limits the current supplied to the motor to a current below a predetermined limit value. ... | 03/22/2005 |
| 6754028 | Control integrated circuit for floppy disk drive A control IC is mounted on a circuit board and is used for driving both a one-inch stepper motor and a half-inch stepper motor. The control IC includes at least a number of pads required for driving the half-inch stepper motor. When the control IC drives the one-inc... | 06/22/2004 |
| 6738213 | Disk drive for controlling maximum current that flows through same A disk drive includes a disk from and to which information can be read and written; a disk driving motor for spinning the disk; a read/write head disposed in the vicinity of the disk; a head transfer mechanism for transferring the read/write head in the radial direc... | 05/18/2004 |
| 6738219 | Seek pattern formation circuit A seek pattern formation circuit includes a seek pattern generation circuit for generating a seek pattern formed of a predetermined pulse train every time a step pulse is applied and a seek pattern shaping circuit for shaping the seek pattern and supplying the shape... | 05/18/2004 |
| 6697210 | Disk device In a disk device, in a state where no access to the disk is permitted, instead of permitting the head to be driven stepwise whenever step pulses are fed in, the head is inhibited from being driven stepwise until a predetermined period of time elapses afte... | 02/24/2004 |
| 6555985 | Stepping motor control device In a stepping motor control method using an encoder, a timer means is provided, and an excessive advance of a phase during low rotation is restricted to attain a high speed without compromising stability during low rotation by driving the motor in such a ... | 04/29/2003 |
| 6515821 | Floppy disk drive control apparatus capable of ensuring seek operation using a stepping motor having a low torque In an FDD control apparatus for controlling a floppy disk drive for driving a floppy disk loaded in the floppy disk drive, an FDD control part including a floppy disk controller (FDC) is disposed in an FDD side in lieu of a host side (a SET side). The hos... | 02/04/2003 |
| 6351093 | Floppy disk drive control apparatus capable of ensuring seek operation using a stepping motor having a low torque In an FDD control apparatus for controlling a floppy disk drive for driving a floppy disk loaded in the floppy disk drive, an FDD control part including a floppy disk controller (FDC) is disposed in an FDD side in lieu of a host side (a SET side). The hos... | 02/26/2002 |
| 6310413 | Steering magnets to reduce magnetic leakage flux in a disk drive A disk drive with steering magnets that reduce the magnetic flux leakage from the actuator magnets of a linear actuator is disclosed. The steering magnets reduce flux leakage in the area of the magnetic disk where magnetic information is read and record, ... | 10/30/2001 |
| 6295507 | Calibration method for acceleration sensor in storage device and storage device Disclosed is a calibration method for an acceleration sensor in a storage device for calibrating and a storage device, an enclosure for calibrating the acceleration sensor for compensating a vibration of an enclosure in a state of its being mounted in a s... | 09/25/2001 |
| 6271636 | Servo control system and method for a data storage device with improved braking A servo control system for a voice coil motor including a servo controller using position feedback to provide an acceleration current to the voice coil motor and voice coil brake providing a deceleration current based upon velocity feedback from the voice... | 08/07/2001 |
| 6147832 | Floppy disk drive with PWM control A floppy disk drive has an exciting current supplying circuit and a control circuit for controlling the exciting current supplying circuit so that the exciting current is increased to a first predetermined value, reduced to a second predetermined value an... | 11/14/2000 |
| 6072656 | Stepping motor control method In a stepping motor control method having an object for correctly and relatively simply determining the position of a pseudo-track center in the dead zone of a stepping motor, a forwardly and reversely rotatable stepping motor is rotated by that a plurali... | 06/06/2000 |
| 6057978 | Disk driving device selectively using delayed step pulses A disk driving device is provided with a stepping motor arranged to move a head in units of a predetermined step with respect to a disk-shaped recording medium and a driving pulse generating circuit arranged to generate driving pulses for driving the step... | 05/02/2000 |
| 6023145 | Head and disk tester with a thermal drift-compensated closed-loop positioning system The head/disk tester of the invention has a housing 43 that houses spindle 44 that rotatingly supports a magnetic disk 31. The housing supports a moveable carriage 30 that, in turn, supports a magnetic head 32. Positioning means 39 and 41 are used to move... | 02/08/2000 |
| 5805375 | Wobble motor microactuator for fine positioning and disk drive incorporating the microactuator A microfabricated wobble motor with a positioning arm attached to the wobble motor rotor acts as a fine positioner with bidirectional movement. The primary application is a rotary actuator for the read/write head in a very small magnetic recording disk dr... | 09/08/1998 |
| 5783884 | Coil components and motor using the coil components A driving motor comprises a rotor having a rotatably supported shaft, a rotor case rotating together with the shaft, a hub seat attached to the rotor case for mounting a disk hub and a chucking magnet for magnetically attracting the disk hub and a thrust ... | 07/21/1998 |
| 5687142 | Disc apparatus having a plurality of reading/recording head driving manners for disc track seeking movement A head reads information from and/or records information to a disc. A head driving unit drives the head on a disc in substantially radial direction thereof, the moving being executed in either a first driving manner or a second driving manner different fr... | 11/11/1997 |
| 5661389 | Compact circuit for controlling a floppy disk driver In a floppy disk driver controlling circuit which is for use in controlling a floppy disk driver including a stepping motor (23) and which comprises a stepping motor driver (21) for producing a driving current to drive the stepping motor and a control sec... | 08/26/1997 |
| 5581421 | Method for driving stepping motor for head seek in disk drive device In a method for driving a head-seek stepping motor of a disk drive device of the kind performing a head seek to move a recording or reproducing head in a radial direction of a disk-shape recording medium by driving the stepping motor according to pulses o... | 12/03/1996 |
| 5552945 | Transducer recalibration system and method for a rotating disk data storage A system for infallibly positioning a transducer on Track Zero on a flexible magnetic disk in the face of possible sensing errors by an optical Track Zero sensor customarily build into a disk drive. The transducer has not been correctly recalibrated if it... | 09/03/1996 |
| 5550447 | Pulse generating system responding to instruction pulses for generating driving pulses for diving motor A pulse generating unit responds to a series of instruction pulses to generate a series of driving pulses which includes alternately occurring first driving pulses and second driving pulses. The pulse generating unit generates the first driving pulses dir... | 08/27/1996 |
| 5545963 | Seek method and apparatus A seek method and an apparatus using a stepping motor, which can eliminate disadvantages of the two-phase excitation (large seek noise and great power consumption) while maintaining advantages of the two-phase excitation (large torque and high stop accura... | 08/13/1996 |
| 5521770 | Disc apparatus having a plurality of reading/recording head driving manners for disc track seeking movement A head reads information from and/or records information to a disc. A head driving unit drives the head on a disc in substantially radial direction thereof, the moving being executed in either a first driving manner or a second driving manner different fr... | 05/28/1996 |
| 5452153 | Servo controlled magnetic head positioner A magnetic recording head positioning system includes a Terfenol-D magnetostrictive rod prestressed by a lever arm to operate in a linear range to microposition the magnetic recording head in accordance with an electromagnetic field. The mechanical advant... | 09/19/1995 |
| 5442497 | Head shifting device in a recording and/or reproducing apparatus In a head shifting device where a head is shifted by a first prescribed amount for every n (ࣙ2) drive steps of a stepwise drive source, the positioning of the head is performed in such a way that before the fact that the head has overrun a prescribed po... | 08/15/1995 |
| 5434724 | Method and apparatus for the high speed driving of a stepper motor against seek error upon power restoration in a microcomputer system A microcomputer system having a flexible magnetic disk drive and a controller therefor, with the disk drive including a stepper motor for incrementally moving a transducer from track to track on a rotating magnetic disk, and a clock which is inherently un... | 07/18/1995 |
| 5408134 | Sub-step pulse generating circuit using the period of a step pulse A circuit for generating a sub-step pulse control signal using a step pulse in a step pulse generating circuit of a floppy disk driver included in a system such a personal computer. The sub-step pulse control signal generating circuit receives a step puls... | 04/18/1995 |
| 5311380 | Magnetic head positioning device and method A servo track recorded on a magnetic tape is traced by a pair of servo track reproduce heads. The output of the pair of servo track reproduce heads are subjected to a subtracting process by a subtractor. A pulse signal is provided to a stepping motor acco... | 05/10/1994 |
| 5264771 | Stepping motor control system The invention concerns with a system for controlling a stepping motor, and more particularly with a stepping motor control system which moves a head of a disk drive unit with (1-2)-phase excitation. With the stepping motor controlling system, a driving fo... | 11/23/1993 |
| 5260634 | Constant current driving system for a stepper motor in rotating disk In order to drive the stepper motor of a floppy disk drive with practically constant current in the face of fluctuations in supply voltage fed from a host system, a power control pulse generator circuit is provided which produces a series of power control... | 11/09/1993 |
| 5231615 | Carriage fixing apparatus and disk driver having such carriage fixing apparatus A carriage fixing apparatus in a disk driver detects that the head carriage which moves a head is located at a predetermined position, and then automatically fixes the head carriage by means of mechanically engaging with the head carriage.... | 07/27/1993 |
