Abstract: A magneto-optic player for reading an information signal stored in a magneto-optical record medium in the form of vertical magnetization including a semiconductor laser emitting a linearly polarized laser light beam, a beam splitter for transmitting the laser light beam, an objective lens for projecting the laser light beam transmitted through the beam splitter onto the record medium and for directing light reflected by the record medium, the light being subjected to Kerr rotation the rotational direction of which is dependent upon the direction of the vertical magnetization. A first quarter-wavelength plate arranged between the objective lens and the beam splitter for converting the linearly polarized light reflected by the record medium into an elliptically polarized light the rotational direction of which is determined by the direction of the vertical magnetization.
Abstract: In a thin film magnetic head having a multilayer structure, a plurality of coil conductive layers are piled up to be formed between a lower magnetic layer and an upper magnetic layer. Each coil conductive layer is formed by one spiral-wound coil. The number of turns of the coil of the upper-side coil conductive layer is set smaller than that of the coil of the lower-side coil conductive layer. These coils are connected together such that first and second portions of the connected coils are respectively connected to a center terminal which is provided at the middle position of the connected coils. Thus, the number of turns of the first portion of the connected coils is set identical to that of the second portion of the connected coils. In addition, the winding direction of the first portion is set reverse to that of the second portion. Such coil conductive layers are surrounded by and buried in an insulation layer formed between the lower magnetic layer and upper magnetic layer.
Abstract: An air filtrating disk drive slot dust protector comprises an air filtrating element attached to the front portion of a disk shaped supporting body, so that insertion of the protector into the disk drive causes the disk drive slot to be blocked by the air filtrating element, thereby keeping the dust from entering the disk drive slot but still allowing the cooling air to pass.
Abstract: A rotary head device having a rotary drum and a rotating motor within the rotary drum, with the stator of the motor being supported by a fixed arm attached to a fixed drum or to a fixed drum supporting member. The construction permits the manufacture of the rotary head device using the manufacturing equipment used for conventional rotary shaft type rotary head devices despite the rotary head device being a thin device. In this rotary head device the position of contact of a ground brush and a rotor can be set at the center of rotation or thereabouts, so despite it being a thin device, the sliding speed of the ground brush is low, and hence it is possible to prevent the abrasion of the ground brush and also to prevent increase of the rotative driving torque.
January 26, 1990
Date of Patent:
June 2, 1992
Hitachi, Ltd., Hitachi Video Engineering Inc.
Abstract: An ejection inhibiting mechanism in a disk memory device of a meidum exchanging type has a latching solenoid for inhibiting the operation of an ejecting mechanism for ejecting a memory medium; an inhibit releasing device for releasing the inhibition of the operation of the ejecting mechanism by the operation of the latching solenoid when a predetermined time has passed after power of the disk memory device is stopped; and a storage battery charged at any time and supplying power to the latching solenoid and the inhibit releasing device. The operation of the ejecting mechanism is inhibited until the rotation of the memory medium is stopped. A cartridge for a disk constructing the memory medium is ejected after the power of the disk memory device is turned off and the rotation of the disk is completely stopped. An attractive state of the latching solenoid is released when the predetermined time has passed.
Abstract: In addition to comprising swivel arms (15) carrying magnetic heads (4), a swivel member (12) seated rotationally movable in a rotational positioner for a magnetic disc storage comprises carrier arms (14) carrying a movable element (16) of a magnetic drive system. A latch means that only releases the swivel member in the operating condition of the disc storage comprises a retainer element (23) radially projecting from the swivel member and also comprises a latch element (19). In the simplest case, this can be fashioned as a leaf spring that engages behind the retainer element when the swivel member enters into a predetermined latched position. For releasing the retainer element, a bipolar enable pulse (v) is supplied to the magnetic drive system (9, 10, 16), this enable pulse first moving the swivel member from the release position beyond the latched position, thereby disengaging the latch means and then moving past the disengaged latch element into the released position with maximum acceleration.
Abstract: In a rotary head drum apparatus having a magnetic head attached to a rotary drum member and connected to a coil of a rotor of a rotary transformer so that a signal is transmitted between the magnetic head and a stationary drum member through the rotary transformer, a resilient contactor is mounted on one of the rotary drum member and the rotor of the rotary transformer, and a contact portion is formed on the other of the rotor and the rotary drum member so as to be contacted by the resilient contactor when the rotary drum and the rotary transformer are assembled with each other. The apparatus further includes an aperture bored through an end face of the stationary drum member and a ground contact pin which is flexible in its radial direction is inserted into the aperture for connecting the stationary drum member to ground.
Abstract: A magnetic disk drive has a mechanism for loading and holding a disk cartridge inserted with a correct orientation at a predetermined position, and for preventing a disk from being inserted with a wrong orientation from being loaded at the predetermined position. The mechanism needs so few members that the magnetic disk drive can be made smaller and thinner. Particularly the mechanism is effective for a magnetic disk drive including a disk cartridge and a driving device. The disk cartridge is an apparatus having at least a disk and a head in a sealed case, but it has no current supply source to drive them and has no controller to control the disk and head. The driving device has the current supply source and/or the controller. The disk cartridge may be considered as being an easily exchangeable hard disk.
Abstract: This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formulaG.sub.d .ltoreq.0.13 P.sub.T B.sub.s (.lambda.+4.3)-2.1.The magnetic disk rotation means rotate the magnetic disk at a speed of 24 m per second or more.
Abstract: A magnetic recording and reproduction device having magnetic heads opposing each other across a magnetic disk. The heads have shaped control portions to generate a negative pressure between the magnetic heads and the magnetic disk in association with rotation of the magnetic disk. One magnetic head is supported by an elastic member which is structured to be slightly dislocatable by the negative pressure. The magnetic heads are caused by the negative pressure to come in sliding contact with both sides of the magnetic disk, thereby obtaining positive sliding contact with extremely small contact resistance between the magnetic heads and the magnetic disk and achieving a good head contact while minimizing abrasion of the magnetic disk and the magnetic heads. The control portions to generate the negative pressure are formed integrally with the magnetic heads, thus simplifying the structure, reducing the manufacturing steps such as positioning procedures and achieving a reduction in cost.
Abstract: In a magnetic tape recording and playback device which has a rotating drum with magnetic heads, a capstan, and reel blocks, the stator coils of motors for driving them are mounted on a board together with electrical circuits for controlling the motors. The electrical circuits and the stator coils of motors are interconnected by conductor patterns formed on the board.
Abstract: A technique for protecting the tape and mechanism of a DAT tape drive that includes engaging a PAUSE mode of operation, wherein the reel motors are off and the tape is stationarily positioned at a predetermined location, when the drive is not able to record or read a data group. If the amount of time during which the PAUSE mode is engaged exceeds a predetermined PAUSE mode limit, a STOP mode of operation, wherein the reel motors remain off and the pinch roller is disengaged from the tape and capstan, is engaged. If the amount of time during which the STOP mode is engaged exceeds a predetermined STOP mode limit, the tape is unloaded.
Abstract: A pad support device for supporting a pad member which is to be pressed against a disk member accomodated in a jacket. A movable member is moved toward and away from the disk member. A plate member carries the pad member, and a leaf spring is formed such that the leaf spring has at least two openings. A first portion of the leaf spring between the at-least-two openings is bent in one direction out of the plane of the surface thereof to be substantially arch-shaped while at-least-two second portions of the leaf spring are bent in a direction in which the first portion is bent to also be substantially arch-shaped. The first portion is secured to one of the movable member and the plate member, while the second portions are secured to the other of the movable member and the plate member, whereby the plate member is resiliently suspended from the movable member.
Abstract: A thin film magnetic head includes an upper magnetic layer comprising a first yoke, a portion of which is divided into front and rear sections and which is provided near the divided sections with a magneto-resistive element, a second yoke provided adjacent to the opposite ends of the first yoke in a widthwise direction of a recording track and a third yoke provided between the first yoke and the second yoke and having a larger magnetic reluctance than those of the first and second yokes. In the above constitution, the first, second and third yokes can be mainly used in recording to record in an area of a large width on the recording medium, and only the first yoke can be used in reproducing to reproduce in an area of a small width on the recording medium, so that the reproducing output is not reduced when the recording medium experiences a running deviation.
July 30, 1990
Date of Patent:
March 17, 1992
Matsushita Electric Industrial Co., Ltd.
Abstract: A cassette tape player utilizes a tape cassette having apertures formed through one side wall of its casing to accept a magnetic head and a pinch roller. The cassette tape player has a body assembly on which the tape cassette is freely loaded or unloaded and a lid supported by the body assembly so as to be freely rotatable for closing and opening the cassette tape player. The tape cassette is inserted into a loading region of the body assembly by closing the lid. A head assembly chassis is supported by one side end portion of the cassette loading portion so that its moves together with the lid. The head assembly also supports a magnetic head holder and the pinch roller. The tape cassette is supported by securing the upper surface wall of the cassette casing by inserting cassette holding members into the pinch roller insertion openings of the tape cassette.
Abstract: There is disclosed a thin film magnetic head which requires less recording current, and is capable of recording and reproducing with a high sensitivity. To achieve this magnetic head, a third yoke of a high permeability is bridged across a notched portion of a second yoke between front and back portions of the second yoke constituting part of a magnetic circuit. With this construction, the third yoke serves to extremely reduce a magnetic resistance between the front and back portions of the second yoke, so that the recording current can be smaller, thereby enhancing the recording efficiency.
July 30, 1990
Date of Patent:
March 10, 1992
Matsushita Electric Industrial Co., Ltd.
Abstract: An E-block assembly is used in a disk drive which reads and writes information to a plurality of magnetic disks. The E-block assembly includes a plurality of sliders, each slider including a magnetic transducer for reading information from one of the plurality of magnetic disks. A plurality of load beams are each coupled to one of the plurality of sliders. A unitary E-block has a first side and a second side and a plurality of load beams is coupled to an arm. The unitary E-block is suitable for being coupled to an actuator for moving the arms relative to the magnetic disks. A plurality of component support members mounted to one of the first or second sides of the unitary E-block has a plurality of component support members. The component support members support electrical components for use in reading information from and writing information to the magnetic disks.
Abstract: Tape cartridge having a T-shaped brake lever or separable brake levers from the slider and forms needle-shaped ends at the ends of a T-shaped brake lever or separable brake levers and prevents the tape from being unwound by enabling the sawteeth parts to catch them but makes the positions of needle-shaped ends facing toward the sawteeth parts take their eccentric positions backward and inward contrary to the point where the former projections are located.
Abstract: An apparatus for attaching the rotor to the spindle hub and minimizing the effects of the difference of thermal expansion of the rotor and the spindle hub upon the discs during thermal cycling. To facilitate minimizing the thermal effects, the rotor outer diameter is smaller than the inner diameter of the spindle hub such that an air gap is maintained between the two parts. One end of the cylindrical back iron portion of the rotor is attached to a radially extending wall portion closing one of the two axial ends of the cylindrical portion of the spindle hub. In other words, the rotor is end-mounted inside the spindle hub. The attachment is accomplished by using screws which extend through the radial extending portion of the spindle hub into one end of the cylindrical back iron portion of the rotor or, in the alternative, by epoxying the two elements together.