Patents Issued in April 20, 2004
  • Patent number: 6724530
    Abstract: To reduce the size of a polarizing device used for a polarized light illuminator, to cut the costs of the polarizing device and to reduce the size of the entire polarized light illuminator, light from a lamp which is incident on a polarizing device, is subjected to polarization separation, and is then incident on an integrator lens. The polarized light emerging from the integrator lens is converted into parallel light via an aperture and a second planar mirror by means of a collimator and is emitted onto a workpiece. As the polarizing element, a polarizing element formed by a combination of several polarized light beam splitters is used, and it is arranged such that the shadow is projected by the boundary surfaces of the polarized light beam splitters onto the boundary lines of the lenses which form the integrator lens. In this way, the reduction in illuminance and the deterioration of the distribution of the illuminance on the irradiation surface can be prevented.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: April 20, 2004
    Assignee: Ushiodenki Kabushiki Kaisha
    Inventors: Shinji Suzuki, Shinichi Umemoto
  • Patent number: 6724531
    Abstract: An optical low-pass filter used in association with an imaging element which has a plurality of pixels arranged in vertical and horizontal direction with regularity, is provided with first through third birefringent plates arranged in the order from a light incident side. The low-pass filter separates an incident ray into four rays, a separation width of the rays in the vertical direction being &dgr;v, and a separation width of the rays in the horizontal direction being &dgr;h. A separation angles of the first through third birefringent plates are &thgr;, (&thgr;−90°) and 0°, respectively, and separation widths of the first through third birefringent plates are (&dgr;v×sin &thgr;), (&dgr;v×cos &thgr;) and &dgr;h, respectively.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: April 20, 2004
    Assignee: PENTAX Corporation
    Inventor: Masahiro Oono
  • Patent number: 6724532
    Abstract: The present invention discloses a dual-lens hybrid diffractive/refractive imaging system comprising: a first lens including a concave surface and a convex surface; and the second lens including a convex surface and a concave surface. The concave surface of the first lens is an objective surface facing the object. The convex surface faces the convex surface of the second lens, while the concave surface of the second lens faces the charge-coupled device (CCD) through a filter. Any surface of the first lens and the second lens is spheric or aspheric. Moreover, the imaging system comprises at least one diffractive surface, referred to as a hybrid diffractive/refractive surface, formed on any surface of the two lenses. Therefore, aberration is eliminated and image quality is improved without increasing the number of lenses.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: April 20, 2004
    Assignee: Industrial Technologies Research Institute
    Inventors: Chiun-Lern Fu, Tsung-Hsin Lin, Hsin-Yih Lin, Mao-Hong Lu, Deh-Ming Shyu
  • Patent number: 6724533
    Abstract: A lamellar volume grating operating in reflection and transmission and providing a substantially wavelength- and polarization-independent diffraction efficiency is disclosed. The lamellar grating has an approximately rectangular grating profile with a height-to-width ratio of the grooves or “teeth” advantageously greater than 2. The grating operates preferably in first order and can be implemented as an immersion grating. In particular, the lamellar volume grating described herein can be employed in an optical multiplexer/demultiplexer arrangement with small overall dimensions.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: April 20, 2004
    Assignee: Chromaplex, Inc.
    Inventors: John Hoose, Robert Frankel, Evgeny Popov
  • Patent number: 6724534
    Abstract: Diffraction optical element used in a scanning optical apparatus as a scanning optical element has a diffraction grating formed on a substrate. The diffraction grating has a tilt portion for generating a power and a wall portion connecting one end portion of the tilt portion to the substrate. The wall portion is tilted within a predetermined range with respect to a normal of the substrate surface. The tilt angle of the wall portion of the diffraction grating with respect to the normal of the substrate continuously changes to increase as a distance away from an optical axis of the diffraction optical element becomes large.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: April 20, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventor: Manabu Kato
  • Patent number: 6724535
    Abstract: An optical device such as an overlay panel for a LCD display, comprises an element of light-transmitting material having a surface configured to form a stepped Fresnel prismatic structure. The light-transmitting material itself or ribbed light refracting element, said element incorporates an array of graded refractive index features adapted to impart light dispersing of diffusing characteristics to the light-transmitting material. In an alternative arrangement, the element of light-transmitting material has a layer configured to form a stepped Fresnel-type surface and an additional layer incorporating such an array of graded refractive index features.
    Type: Grant
    Filed: October 14, 2001
    Date of Patent: April 20, 2004
    Assignee: Microsharp Corporation Limited
    Inventor: Robin Clabburn
  • Patent number: 6724536
    Abstract: There is disclosed a partially transparent, directional viewing sheet formed of plastic material with convex and concave lenses, preferably lenticular lenses, formed respectively on the front and back surfaces of the sheet, there being intervening spaces with flat or convex arcuate surfaces between the concave lenses which spaces are not transparent to images and may be imprinted with an image that is viewable through the sheet from some directions. Preferably the concave lens focal length is typically about one-half of the focal length of the convex lens. Elliptical cross-section of the lenses may minimize spherical aberration and sharpen the focus. The thickness of the sheet causes focal points of the lenses to substantially coincide.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: April 20, 2004
    Assignee: University of Arkansas
    Inventor: John Allan Magee
  • Patent number: 6724537
    Abstract: A miniaturized lens array for unity magnification imaging comprises a plurality of rod lenses arranged in one row. An arrangement pitch D of the rod lenses is defined to satisfy (2 m+1)·D≦2.1 mm or 2.5 mm. An angle of aperture &thgr; of the rod lens is defined to satisfy &agr;D/6×{n·cos−1(−&agr;/2/m)+(4 m2/&agr;2−1)1/2}≦&thgr;≦&agr;D/2×(4/m2/&agr;2−1)1/2. The arrangement pitch D and angle of aperture &thgr; are defined in this manner, and it is therefore possible to obtain the lens array whose difference between a total width and effective lens width is equal to or smaller than 2.1 mm or 2.5 mm.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: April 20, 2004
    Assignee: Nippon Sheet Glass Co., Ltd.
    Inventor: Shuya Ogi
  • Patent number: 6724538
    Abstract: A head-up display is provided which is suitable for a motorcycle. An image is present in peripheral fields outside a 90% center field. In the case where the image is located outside the 90% center field, it does not obstruct driving of the vehicle, and in the case where the image is located in the peripheral fields, it allows a driver to dimly see the shape of the image and thereby recognize the presence of the image. For this reason, the image is located in the peripheral fields. Since an image is located in a peripheral field, the presence of the image can be recognized by a driver while not obstructing a desirable visibility to the front side of the driver. The driver can recognize, on the basis of the presence or absence of the image, whether or not attention should be taken to drive the vehicle.
    Type: Grant
    Filed: April 3, 2001
    Date of Patent: April 20, 2004
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Kazumitsu Kushida, Norihiro Kurata, Sadanao Ichimi
  • Patent number: 6724539
    Abstract: The light which is input from an optical fiber to a first port is output to an optical path. The light which is input from the optical path to a half mirror is branched into two, and is output to the optical paths. The light which is output to the optical path reaches to and is reflected from a first reflecting mirror, and returns to the half mirror by an optical path. The light which is input to the half mirror by the optical path is branched into two, and is output to the optical paths. The light which is output to the optical path reaches to and is reflected from a second reflecting mirror, and returns to the half mirror by an optical path. The light which is input to the half mirror by the optical path is branched into two, and is output to the optical paths. The light which is output to the optical path is output from a second port to an optical fiber, and the light which is output to the optical path is output from a third port to an optical fiber.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: April 20, 2004
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tamoya Kenmochi, Hiroshi Suganuma, Tomomi Sano, Tetsuya Iimura
  • Patent number: 6724541
    Abstract: An aperture regulating apparatus includes a moving barrel moving straight in an optical axis direction, a rotation barrel rotatably held by the moving barrel, a cam member movably fitted on the moving barrel, and a shutter unit movably contained in the moving barrel. In moving the moving barrel in the optical axis direction by magnifying operation, the rotation barrel moves in the optical axis direction with the moving barrel with rotation, and the cam member moves in the optical axis direction on an outer surface of the moving barrel in accordance with rotation of the rotation barrel. The shutter unit has a regulation lever getting in rotational range of shutter blades. The regulation lever is displaced according to movement of the cam member to control a rotational amount of the shutter blades. An aperture size is regulated according to a focal length of a taking lens.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: April 20, 2004
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventor: Yukio Noguchi
  • Patent number: 6724542
    Abstract: An integrated light-transmission optical module for a safetyoptoelectronic barrier, comprises a condenser element having a first lens, and an objective having a second lens which are located respectively at a first end and a second end. The module comprises a single-piece entity made of transparent material, and having an intermediate zone provided with deflectors formed by a succession of dioptric surfaces distributed along the direction of light flux propagation between the first lens and the second lens. The deflectors ensure a deflection outside the optical module of stray rays reflected inside the module, so as to prevent transmission of strays rays, either through the second lens of the objective if it is a light transmission coming from the condenser element, or through the first lens when receiving light coming from the second lens.
    Type: Grant
    Filed: June 5, 2002
    Date of Patent: April 20, 2004
    Assignee: Honeywell
    Inventors: Didier Lenoire, Dominique Godfroy, Marek Gierczak
  • Patent number: 6724543
    Abstract: A lens assembly is disclosed for use with various light emitting sources. The lens assembly includes a central section and an outer section. The central section is radially centered on an optical axis. The outer section radially surrounds the central section and is radially centered on the optical axis. The outer section includes an outer wall that has a generally rotated parabolic shape, an inner wall that abuts the central section, and a slanted front surface extending between the inner wall and the outer wall. The front surface is the area of the lens assembly axially farthest away from the light emitting source.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: April 20, 2004
    Assignee: Visteon Global Technologies, Inc.
    Inventors: Jeyachandrabose Chinniah, Edwin M. Sayers, Balvantrai G. Patel
  • Patent number: 6724544
    Abstract: An optical lens whose focal length is different on first and second planes perpendicular to each other is provided. The optical lens is configured such that a convex element, which is formed integrally with a substrate having a flat face, has a convex curved face that functions as an optical lens and is shaped such that the curvature on a first cross section and the curvature on a second cross section perpendicular to and intersecting with the first cross section are different from each other, whereby the focal lengths on the first and second cross sections are different from each other. A groove of a substantially elliptical shape or a substantially rectangular shape is formed along the boundary between the substrate and the convex element. The optical lens is used to produce a focus error signal or is incorporated into an optical pickup apparatus.
    Type: Grant
    Filed: January 23, 2002
    Date of Patent: April 20, 2004
    Assignee: Sony Corporation
    Inventors: Koichiro Kishima, Akira Kouchiyama
  • Patent number: 6724545
    Abstract: Provided in the present invention are an image pickup lens and a design method thereof which can achieve miniaturization of the system and capable of remarkably improving the optical characteristic with a simple structure. By forming a second face on the image pickup surface side of a lens body into a Fresnel face and unifying a diffraction element with at least a first face on the object face side or the second face on the image pickup surface side of the lens body, it becomes possible to correct the Petzval sum and reduce the curvature of the field so that an excellent image plane can be obtained. Also, due to the color dispersion characteristic of the diffraction element, chromatic aberration can be well corrected. Thereby, the optical characteristic of the image pickup lens can be remarkably improved.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: April 20, 2004
    Assignee: Enplas Corporation
    Inventors: Masato Nakamura, Takayuki Arai, Isamu Kaneko
  • Patent number: 6724546
    Abstract: Lengths of both sides of each end plane of a light-intensity distribution uniformizing element receiving a light flux and having an F-number of 1 are set to ½ of those of a reflecting surface of a reflecting optical-spatial modulator element, position information of uniformed light fluxes output from the light-intensity distribution uniformizing element is Fourier-transformed into diverging angle information indicated by incident light fluxes output from a first group of lenses, a relay deformed diaphragm intercepts an interference component of each incident light flux, which is expected to interfere with an outgoing light flux, to produce asymmetric light fluxes, the asymmetric light fluxes are incident on the reflecting optical-spatial modulator element, a projection lens deformed diaphragm removes stray light from outgoing light fluxes output from the reflecting optical-spatial modulator element, and an image is displayed according to the outgoing light fluxes.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: April 20, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Junichi Nishimae, Akira Sekiguchi, Tomohiro Sasagawa, Yoshiyuki Goto, Kohei Teramoto, Hiroyuki Kawano, Tatsuki Okamoto, Yukio Satou, Atsuhiro Sono
  • Patent number: 6724547
    Abstract: A single-focus lens includes from the object side, a first lens with a positive refracting power having at least one aspheric surface, a stop, a second lens with a negative refracting power, and a third lens with a positive refracting power having at least one aspheric surface. This single-focus lens further satisfies the conditional expression of 0.3<f/f2′3<0.8, where f is the focal length of the lens as a whole, and f23 is the composite focal length of the second and third lenses.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: April 20, 2004
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventor: Kenichi Sato
  • Patent number: 6724548
    Abstract: An objective, in particular a projection lens for microlithography, is provided with at least one optical element (8) that is mounted in an inner mount (9a), the inner mount (9a) being connected to the outer mount (9b). A manipulator device (21) performs a displacement of the optical element (8), preferably in at least one direction that lies at least approximately parallel to the optical axis. At least one elastically deformable strip (13) is arranged in a gap (12) between the inner mount (9a) and the outer mount (9b), the strip being connected in each case via a fastening section (15) to the inner mount (9a) and the outer mount (9b), and the two fastening sections (15) being connected to one another by an arcuate section (18, 19) and free bearing parts (16, 17) situated therebetween.
    Type: Grant
    Filed: February 26, 2003
    Date of Patent: April 20, 2004
    Assignee: Carl Zeiss SMT AG
    Inventor: Ulrich Weber
  • Patent number: 6724549
    Abstract: In the case where a magnetic transfer process is used to record a specific magnetic pattern during the magnetic disk manufacturing process, a read/write tester for conducting a glide height test and a read/write test and a particle testing means are provided at the front section of a magnetic transfer device. The tester records a specific magnetic pattern onto a magnetic disk in a magnetic transfer method. An optical testing device, a read/write tester for conducting a glide height test, and a read/write test in sampling are provided at the rear section of the device. This enables the detection of consecutive disk abnormalities caused by particles, which are adhered a master disk or put between the magnetic disk and the master disk. A transfer quality control device collects the results of the respective tests, so that the quality can be controlled using the results. Accordingly, the present invention assures the desired quality of a magnetic disk produced after transfer.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: April 20, 2004
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Hironori Mine
  • Patent number: 6724550
    Abstract: A method for the adaptive dampening of a peak amplitude of a thermal asperity signal in a disc drive to minimize loss of read data integrity, including the steps of determining a peak-to-peak preamble signal amplitude for identifying an amplitude signal range of the peak amplitude of the thermal asperity signal; measuring the peak amplitude of the thermal asperity signal; separating the peak-to-peak preamble signal amplitude into substantially even portions for use in calculating a value of the amplitude signal range of the peak amplitude of the thermal asperity signal; calculating the value of the amplitude signal range of the peak amplitude of the thermal asperity signal for use in determining a dampening resistance used by a dampening circuit to adaptively dampen the peak amplitude of the thermal asperity signal; and activating the dampening circuit to dampen the peak amplitude of the thermal asperity signal.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: April 20, 2004
    Assignee: Seagate Technology LLC
    Inventors: Eng Hock Lim, Beng Theam Ko, Hweepeng Teo, Fong Kheon Chong, Myint Ngwe, Kah Liang Gan
  • Patent number: 6724551
    Abstract: A differential circuit to read differential data from a disk by a current bias on a plurality of read heads includes a read circuit to read the differential data from the disk by maintaining the current bias. The current is below a maximum current of a read head having the lowest maximum voltage of said plurality of read heads.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: April 20, 2004
    Assignee: Texas Instruments Incorporated
    Inventor: Indumini W. Ranmuthu
  • Patent number: 6724552
    Abstract: A magnetic disk apparatus is capable of reading normal data following a read error of a reference signal that has occurred due to a scratch or the like on a disk surface. In the magnetic disk apparatus, if a reference signal (STM) fails to be read at point P, then an elapsed time (Tw) is measured, and a time T2 indicating the difference between a time T1 at which a read gate is supposed to be opened and the time Tw is determined. The read gate is opened after the time T2 has passed, thereby making it possible to properly read data and subject the read data to a decoding process.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: April 20, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Takayuki Sugawara, Takahiro Kawauchi, Masahiro Tenpaku, Yoshiyasu Kubota
  • Patent number: 6724553
    Abstract: A method for writing and reading data in a hard disk drive and compensating for an offset between a write element and a read element of a head. The method determines an offset time by determining the difference between a desired sync byte position and an actual sync byte position located between a preamble and a data sector of the disk. The difference corresponds to the offset between the read and write elements. The offset time is subtracted from the normal time for enabling the read gate of a disk drive pre-amplifier.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: April 20, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jong Yun Yun, Kang Seok Lee, Sang Hoon Chu, Gyu Tack Kim
  • Patent number: 6724554
    Abstract: A method of inhibiting inadvertent and unauthorized writing and reading of information to and from a storage medium comprises the steps of (a) writing a first code in a predetermined location on the storage medium, the first code being indicative of a first protection mode of the storage medium; (b) receiving a command to change the protection mode of the storage medium from the first protection mode to a second protection mode; and, in response to the command, (c) writing in the predetermined location on the storage medium, in place of the first code, a second code indicative of the second protection mode. A protection mode can inhibit writing to the storage medium, both writing and reading to and from the medium, or neither. Changing of protection modes can also be password protected.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: April 20, 2004
    Assignee: Iomega Corporation
    Inventors: David G. Braithwaite, Clark C. Bruderer, Gregory M. Allen, David A. Thompson
  • Patent number: 6724555
    Abstract: A data detecting method and its apparatus for equalizing an input signal reproduced from magnetic recording media by partial response by employing at least one of partial response class 4 (PR4) and extended partial response class 4 (EPR4), and decoding the input signal. The input signal is equalized by PR4, and a first equalized signal is obtained. First decoded data is obtained from the first equalized signal. The input signal is equalized by EPR4, and a second equalized signal is obtained. Second decoded data is obtained from the second equalized signal. From the first equalized signal and second equalized signal, the signal condition of the input signal is judged, and the optimum data detecting method is discriminated. Thus, either the first decoded data or second decoded data is selected as detected data.
    Type: Grant
    Filed: March 12, 2001
    Date of Patent: April 20, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Haruo Ohta
  • Patent number: 6724556
    Abstract: A differential circuit to read differential data from a disk by a voltage bias includes a read circuit having a read circuit pole to read the differential data from the disk by maintaining the voltage bias and a feedback circuit having a feedback pole to sense deviations in the voltage and to adjust the voltage in response to the deviations. The read circuit pole is separated from the feedback pole in frequency.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: April 20, 2004
    Assignee: Texas Instruments Incorporated
    Inventors: Indumini W. Ranmuthu, Hong Jiang
  • Patent number: 6724557
    Abstract: A magnetic recording apparatus has a rotating drum which rotates magnetic heads at a constant speed. The magnetic heads scan a magnetic tape. On a magnetic tape, an area written by each scan always includes a lateral portion of an area written by the previous scan. In this portion, old data is overwritten by new data, and writing continues. An area excluding the overwritten portion is a recording track. The running speed of the magnetic tape is changed by a system controller, and hence the recording track width can be changed.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: April 20, 2004
    Assignee: Sony Corporation
    Inventor: Morihiko Sato
  • Patent number: 6724558
    Abstract: A method and apparatus for reading and writing data from and to a data storage disc in a data storage device. The data storage disc includes a first disc surface and second disc surface for storing data. The data storage device includes an actuator assembly configured to selectively position a first transducer over the first disc surface and a second transducer over the second disc surface, wherein the first transducer is substantially identical to the second transducer. Furthermore, each transducer includes a read element and a write element, wherein the read element is offset from the write element by at least the width of one servo track.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: April 20, 2004
    Assignee: JPMorgan Chase Bank
    Inventors: Lawrence Matthias Bryant, Karl Arnold Belser, Robert Dale Murphy
  • Patent number: 6724559
    Abstract: A magnetic tape unit includes a magnetic tape provided with a plurality of tracks, a magnetic head for writing or reading data from the tape, a position determiner for monitoring the relative position between the tape and the head, and a position compensator for adjusting this relative position. The monitoring by the position determiner is performed based on signals read out from the servo control tracks of the tape. The position compensator keeps the magnetic head and tape in proper positional relation based on the results of the monitoring by the position determiner.
    Type: Grant
    Filed: November 1, 2000
    Date of Patent: April 20, 2004
    Assignee: Fujitsu Limited
    Inventors: Hironao Konishi, Tatsuya Yumioka, Masaharu Tosa, Takanobu Kashiwagi, Yukio Sekiguchi, Tadayoshi Yamamoto, Hiroyuki Miyata
  • Patent number: 6724560
    Abstract: A head suspension supporting a head at the tip end is allowed to swing at the tip end of a carriage in a recording disk drive. A microactuator is interposed between the head suspension and the carriage. A resistor is connected to the microactuator in serial. The microactuator is allowed to function as a capacitance. A combination of the microactuator and the resistor enables establishment of a so-called low pass filter. A high frequency noise involuntarily introduced in the driving voltage for the microactuator can be eliminated or removed from the driving voltage. Elimination of the high frequency noise enables a reliable prevention of the mechanical or physical resonance or vibration in the head suspension. A tracking action of the head related to a target recording track can reliably be stabilized.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: April 20, 2004
    Assignee: Fujitsu Limited
    Inventors: Shinji Koganezawa, Takahiro Imamura
  • Patent number: 6724561
    Abstract: An apparatus and method for compensating for environmental effects on media. The apparatus includes an array of servo readers that are positioned at a non-zero azimuth angle relative to a medium. The position of the array of servo readers is dynamically updateable in both a vertical direction and an azimuth angle direction based on a combination of an average position error signal of both an upper portion of the servo readers and a lower portion of the servo readers. Based on the average position error signal and a reference signal, a controller generates control signals that are output to one or more actuators. The actuators then adjust the position of the array of servo readers based on the control signals received.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: April 20, 2004
    Assignee: Storage Technology Corporation
    Inventor: Robert O. Wyman
  • Patent number: 6724562
    Abstract: A method for writing servo patterns on at least one disc in a disc drive that has a first set of tracks and a second set of tracks on a major surface of the disc includes stepping between the tracks of the first set of tracks at a first constant angle, and stepping between the tracks of the second set of tracks at a second constant angle. Stepping between tracks in the first group or the second group includes selecting two adjacent tracks from either the first group of tracks or the second group of tracks, and determining the angle through which an actuator assembly must be rotated between the two adjacent tracks selected to produce a selected track pitch. The method produces a disc for a disc drive with a first set of tracks, and a second set of tracks in which the track pitch varies across the set of tracks.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: April 20, 2004
    Assignee: Seagate Technology LLC
    Inventors: Chiap Heok Ang, Niroot Jierapipatanakul, Beng Theam Ko, Myint Ngwe, Beng Wee Quak, Choonkiat Lim
  • Patent number: 6724563
    Abstract: By increasing the gain of a controller for coarse motion CFBV within a frequency band in which the gain of a sensitivity function SP=1/(1+PP·CFBP) of fine motion actuator DP and controller for fine motion CFBP exceeds 0 dB, the gain of a sensitivity function SV=1/(1+PP·CFBV) of coarse motion actuator PV and coarse motion controller CFBV is decreased. Through this, in a two-stage actuator control system, a disk apparatus can be provided in which a sensitivity function SPES=1/(1+PP·CFBP)·1/(1+PP·CFBV) indicative of a disturbance compressive ratio in a signal path ranging from disturbance components to a head position error signal is rendered to be 0 dB or less at all frequencies concerned.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: April 20, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masahito Kobayashi, Masaki Odai
  • Patent number: 6724564
    Abstract: A disk drive and methods for preventing a coil in a voice coil motor from overheating due to the application of excess current. The disk drive comprises a servo control system. The servo control system is adapted for applying a current to a coil of the voice coil motor thereby causing the voice coil motor to move the head according to a seek distance. The servo control system generates a plurality of seek profiles for each of a plurality of seek distances and a plurality of current limits for the plurality of seek profiles. Each of the plurality of seek profiles defines a plan for controlling the current to be applied to the coil while the voice coil motor is operated over the seek distance. The plurality of current limits each define a maximum current allowed while controlling the current to be applied to the coil.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: April 20, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, David D. T. Nguyen, David L. Whitaker
  • Patent number: 6724565
    Abstract: In a tape loading device, a loading drive gear rotates about a shaft. The loading drive gear includes a U-shaped groove in which the shaft is disposed and a spring accommodating portion disposed continuously to the U-shaped groove. The first and second arms are rotated by the rotation of the loading drive gear, whereby sliders are moved along guide openings so as to wind a tape around a drum. When the tape has been loaded, the sliders are stopped by catchers. When the loading drive gear is further rotated, the shaft thereof is moved to the spring accommodating portion, and an energizing force is generated to a spring and exerted on the first and second arms in a direction where the sliders are pressed against the catchers. With this operation, the positions of the sliders are fixed so that the tape can stably travel. Since the spring is contained in the loading drive gear, the number of parts can be reduced as well as the tape loading device can be arranged simply and assembled easily.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: April 20, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Susumu Hisadomi
  • Patent number: 6724566
    Abstract: A disc drive device includes a base plate, a voice coil motor operably attached to the base plate, a top cover attached to the base plate with at least two perimeter fasteners and at least one interior fastener, wherein the two perimeter fasteners and the interior fastener form a triangular portion of the top cover therebetween, a pressure seal sealing the top cover and the base plate, and an acoustic damper contacting the voice coil motor and the triangular portion of the top cover for damping vibrations occurring in the voice coil motor and the top cover. The acoustic damper is made of the same material as the pressure seal. In this manner, vibrationally induced acoustical emissions from the disc drive device are reduced.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: April 20, 2004
    Assignee: Seagate Technology LLC
    Inventors: Rishi Kant, Menachem Rafaelof, Michael Alan Maiers
  • Patent number: 6724567
    Abstract: A disc mounting system for mounting the discs of a disc drive in a fixed radial relationship to the hub of a spindle motor. The disc mounting system includes curved spring elements, having a substantially C-shaped cross section, which are curved on a radius greater than the radius of the central opening of the discs. One or more spring elements are utilized with each disc, and assembly tooling is used to bend the spring elements so that the discs, with the opening of the C-shaped springs engaging the inner diameter of the discs, can fit over the hub of the spindle motor. The assembly tooling is then removed to allow the spring elements to partially straighten, firmly engaging the discs relative to the spindle motor hub in the radial direction. In a first embodiment of the invention, alternative mechanisms are disclosed for establishing the axial positions of the discs.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: April 20, 2004
    Inventors: Frederick Frank Kazmierczak, Michael John Raffetto
  • Patent number: 6724568
    Abstract: A clamp for securing data storage disks to a hub of a disk drive mechanism includes a flat body with a protuberance that defines a flat distal surface for engaging a data storage disk. The body also includes bores that receive members for securing the clamp to the hub and at least one groove for distributing the securing force of the securing members.
    Type: Grant
    Filed: May 23, 2001
    Date of Patent: April 20, 2004
    Assignee: Maxtor Corporation
    Inventors: Wantjinarjo Suwito, James D. Fahey
  • Patent number: 6724569
    Abstract: Embodiments in accordance with the thin film write head of the present invention have a lower pole structure, an upper pole structure, and a multilayer write gap extending from an air bearing surface between the upper and lower pole structures. In preferred embodiments, the write gap comprises at least two of: (a) a first layer covering a lower pole tip portion of the lower pole structure, (b) a second layer covering turns of a semiconductor winding, or (c) a third layer covering a winding insulation stack. In more preferred embodiments, the write gap is formed of the first, the second, and the third write gap layers. An advantage of a write head with a multilayer write gap is that it allows better control of write gap thickness. As such, loss of write gap thickness can be compensated for by deposition of the second write gap layers, or by deposition of the third write gap layer.
    Type: Grant
    Filed: August 23, 2002
    Date of Patent: April 20, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Yingjian Chen, Kyusik Sin, Ronald A. Barr
  • Patent number: 6724570
    Abstract: A thin film magnetic head having excellent recording characteristics is provided. In a structure of the thin film magnetic head, a thickness LT (&mgr;m) of a top pole chip and a distance LD (&mgr;m) between a position of a front edge surface of a top yoke and a position of an air bearing surface are adapted to satisfy LD≧LT−2.0 (&mgr;m) (LD≧0, LT<0). In the thin film magnetic head having such structural features, the above-mentioned thickness LT and distance LD having an influence upon recording characteristics are optimized, and thus the occurrence of side erase during recording can be prevented.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: April 20, 2004
    Assignee: TDK Corporation
    Inventors: Makoto Yoshida, Taro Oike, Atsushi Iijima
  • Patent number: 6724571
    Abstract: A magnetic head for a hard disk drive. The magnetic poles of the head are formed with a NiFe alloy having a graduated composition in which a higher Fe concentration is fabricated proximate the write gap layer between the magnetic poles. Each magnetic pole is fabricated in a single electroplating step in which the duty cycle of the electroplating current is altered during the electroplating operation. Where the duty cycle is greatest the Fe ion concentration is likewise greatest.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: April 20, 2004
    Assignee: International Business Machines Corporation
    Inventors: Thomas Edward Dinan, Neil Leslie Robertson, Alan Jun-Yuan Tam
  • Patent number: 6724572
    Abstract: In one aspect, an inductive transducer is disclosed having a leading pole layer and a leading pole tip, with the pole layer being further removed than the pole tip from a media-facing surface. In another aspect, an inductive transducer is disclosed having a magnetic pedestal disposed between a leading pole layer and a leading pole tip, with at least one of the pedestal and pole layer being further removed than the pole tip from a media-facing surface. In another aspect, a leading pole layer or pedestal may have a surface that slopes away from the media-facing surface with increasing distance forward from the leading pole tip.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: April 20, 2004
    Assignee: Western Digital, Inc.
    Inventors: Kroum Stoev, Yugang Wang, Francis Liu, Yingjian Chen, Xiaozhong Dang
  • Patent number: 6724573
    Abstract: Disclosed is a tape cassette including a cassette shell in which two tape reels are rotatably contained; a front lid, turnably supported by the cassette shell, for opening/closing the front side of a tape-like recording medium crossing a front portion of a mouth portion provided in a front portion of the cassette shell in such a manner as to be opened forwardly, upwardly, and downwardly; and a lid lock member for locking the front lid in the closed state to the cassette shell, wherein the locking of the front lid by the lid lock member is released when the tape cassette is mounted in a tape drive apparatus; the lid lock member is biased in the locking direction by biasing means; and the lid lock member is engaged with and held by a tape cassette side member in the unlocking state. With this configuration, the mounting state of the tape cassette in a tape drive apparatus can be stabilized and also the size and weight of the tape drive apparatus can be reduced.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: April 20, 2004
    Assignee: Sony Corporation
    Inventor: Shuichi Ota
  • Patent number: 6724574
    Abstract: A HGA includes a magnetic head slider having at least one thin-film magnetic head element, an IC chip having a circuit for the at least one thin-film magnetic head element, and a suspension for supporting the magnetic head slider and the IC chip. All surfaces of the IC chip are coated by additional insulation layers.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: April 20, 2004
    Assignee: TDK Corporation
    Inventors: Takeshi Wada, Mitsuyoshi Kawai, Takao Matsumoto, Atsushi Hirose, Masashi Shiraishi
  • Patent number: 6724575
    Abstract: The present invention is a method and apparatus for providing an electrical substrate. The electrical substrate comprises a dielectric layer; and a first conductive layer attached to the dielectric layer, in which the first conductive layer has an elliptical cross-section. The electrical substrate may be used in a flexible circuit that connects the read/write head to electronic circuitry in a hard disk drive.
    Type: Grant
    Filed: November 15, 2000
    Date of Patent: April 20, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Eunkyu Jang
  • Patent number: 6724576
    Abstract: In a magnetic disk apparatus including a base, a magnetic head, a magnetic disk, and a spindle motor having a stator fixed to the base and a rotor for mounting the magnetic disk, a ramp road structure for parking the magnetic head is fixed to the stator.
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: April 20, 2004
    Assignee: TDK Corporation
    Inventor: Shunji Noda
  • Patent number: 6724577
    Abstract: The structure is made such that an aerodynamic latch is provided in an outer portion of a magnetic disc, a front end portion exposed to a wind in the aerodynamic latch is formed to be shorter than an outer peripheral surface of the magnetic disc, and the wind receiving portion of the aerodynamic latch moves an air stream outlet from an end surface of the magnetic disc and a shroud in a direction of forming a flow passage for passing through a portion apart from the magnetic disc. Accordingly, a stable aerodynamic latch drive can be achieved and an air stream within the disc is not disturbed, so that it is possible to reduce a flutter and a consumed electric power.
    Type: Grant
    Filed: February 23, 2001
    Date of Patent: April 20, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Ishii, Takashi Kouno, Hayato Shimizu
  • Patent number: 6724578
    Abstract: The present invention provides a thin actuator which is used for transferring a head of a magnetic disk drive, and prevents resultant malfunctions. In a moving part of the actuator in which a coil, holding member, housing, and plate-shaped terminals are integrated by resin molding, the plate-shaped terminals are provided in the holding member in a coil moving direction, and the plate-shaped terminals and connecting parts provided in a conductor end part of the flexible circuit board are brought into surface contact, and these contacted portions are electrically connected with solder.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: April 20, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Masashi Watanabe
  • Patent number: 6724579
    Abstract: In a head drum assembly mounting structure on a deck of a tape recorder, a plurality of connecting holes and positioning holes are formed in a drum boss provided at a lower portion of a fixing drum, and a plurality of coupling holes and positioning pins are formed in a drum base which is slant disposed on a main base. By using the positioning holes and the positioning pins as positioning means which are connected to each other in complementary fashion, the coupling holes of the drum base and the connecting holes of the drum boss are aligned with each other, and by fastening a screw into such aligned coupling holes and the connecting holes, the head drum assembly can be directly coupled to the main base while being slant disposed with respect to the main base. Accordingly, any possible damage to a lead line is prevented, and assembly efficiency is improved, while the number of parts and the manufacturing cost are reduced.
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: April 20, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Yong-chae Jeong
  • Patent number: 6724580
    Abstract: An actuator of the present invention includes a shape maintaining sheet, a piezoelectric member provided integrally on the shape maintaining sheet, and a pair of electrodes formed to sandwich the piezoelectric member, wherein the shape maintaining sheet is formed of synthetic resin. Since the piezoelectric member is thin, the stiffness is increased by the shape maintaining sheet made of synthetic resin, and thus resonance frequency can be adjusted.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: April 20, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yousuke Irie, Kazuo Yokoyama