Abstract: A tilt control apparatus includes an orthogonal shift detector (9) which detects an orthogonal shift by comparing a pair of a plurality of tap coefficients (C1, . . . , C7) of a FIR filter and generates an orthogonal shift signal, and an actuator varies the inclination of the optical axis of the light beam to correct the orthogonal shift, and a tilt controller (10) controls the drive of the actuator in accordance with the orhogonal shift signal to minimize the orthogonal shift. In the information recording operation, the orthogonal shift obtained based on a recording track is previously stored in a temporary storage portion and the stored orthogonal shift is used to conduct the tilt control.

Abstract: An optical head performs recording and/or reproducing of a signal to an optical recording medium and comprises a light source, an objective lens converging the light emitted from the light source to the optical recording medium, and objective lens tilting mechanism for tilting the objective lens in order to correct aberration generated when the optical recording medium is tilted, and the optical head is assembled so that a direction of the coma aberration of the objective lens itself perpendicularly crosses a direction tilted by the objective lens tilting mechanism.

Abstract: An optical head device includes a light source for emitting light; a collection optical system for collecting the light emitted by the light source to an information memory medium including tracks having prescribed grooves; a light detector having a plurality of detection areas for receiving the light reflected by the information memory medium and outputting a signal in accordance with a light amount of the light received; a tracking error signal generator for receiving the signals output from the light detector and generating a tracking error signal based on the signals; and a light division element for dividing a reflected light reflected by the information memory medium.

Abstract: An optical recording/reproducing apparatus includes an optical pickup recognizing information of an optical disc; a main shaft and a sub-shaft oppositely installed on a base plate, for supporting the optical pickup; a fixing portion for movably supporting one end of the main shaft; a support portion installed on the base plate at a certain distance from the fixing portion, for elastically supporting the other end of the main shaft; a prop portion installed on the base plate, for supporting a bottom middle surface of the main shaft; and a skew adjustment screw rotatably installed at the base plate, for upwardly pushing an end of the main shaft supported by the support portion.

Abstract: An apparatus and method for high-speed searching of an optical medium having a plurality of tracks. Light spots are directed by the apparatus onto the optical medium. As the spots traverse across the tracks in one of a first direction and a second direction, a photodetector unit receives reflected components of the light spots, thus forming respective electrical signals. Digital shaping circuitry converts the electrical signals into digital signals. A quadrature detector receives the digital signals which are arranged in quadrature relationship to each other, and produces an up-count signal indicating the light spots are traversing the tracks in the first direction and a down-count signal indicating the light spots are traversing the tracks in the second direction. A counter counts the up-count signal and the down-count signal to determine a number of tracks traversed by the light spots.

Abstract: An objective lens driving apparatus includes a lens holder 1 that holds an objective lens 2, and a stationary base 9 that supports the lens holder 1 by a support shaft 3 parallel to an optical axis of the objective lens 2. A stationary yoke 11 and the magnet 8 are mounted to the stationary base 9. A focusing coil 4 and the tracking coils 5a and 5b are mounted to the lens holder 1. The interaction between the current in the focusing coil 4 and the magnetic field caused by the magnet 8 generates an electromagnetic force that moves the lens holder 1 along the support shaft 3. The interaction between the current in the tracking coils 5a and 5b and the magnetic field caused by the magnet 8 generates an electromagnetic force that rotates the lens holder 1 about the support shaft 3.

Abstract: A tracking controller includes a tracking error detecting section and a tracking control section. The tracking error detecting section generates and outputs a tracking error signal that represents how much the focal point of a light beam has shifted from a target track on a storage medium. The tracking control section generates a drive signal in response to the tracking error signal so as to move the light beam such that the focal point of the light beam is located right on the target track. The gain of at least one of the tracking error signal and the drive signal is switched depending on whether or not the focal point of the light beam is located on a recorded area of the storage medium on which data has already been written.

Abstract: A deflector deflects laser light emitted from a laser light emitting device. A lens driver moves an objective lens for conversing the laser light deflected by the deflector onto an optical recording disk in a focusing direction and a tracking direction thereof. A frame member supports the laser light emitting device, the deflector and the lens driver. The deflector is positioned such that the center of an intensity distribution of the laser light is aligned with an optical axis of the objective lens.

Abstract: An optical head device including a photo detector and an optical system which converges a laser beam emitted by a laser light source onto an optical recording medium and also guides a returning beam from the optical recording medium to the photo detector. The optical head device further includes a base on which the laser light and the photo detector are mounted. An optical element is mounted on the base via an optical element holder which has the same linear expansion coefficient as that of the base and is fixed with adhesive directly to the base. The optical element is fixed on a surface which is perpendicular to a device optical axis of the element holder.

Abstract: An optical pickup apparatus including a swing arm pivotably installed in a tracking direction with respect to a disc, and an optical pickup unit supported by the swing arm and driven in a focusing direction, wherein the optical pickup unit includes a laser diode, an objective lens to focus light emitted from the laser diode on a recording surface of the disc, and a heat sink plate to dissipate heat generated from the laser diode, wherein the heat sink plate is provided close to the disc so as to be directly exposed to wind generated during rotation of the disc.

Abstract: An optical head apparatus according to the present invention has a flat coil in which a focusing coil and a tracking coil are integrally formed on both surfaces or one surface of a pair of insulative.

Abstract: 0 In an optical pickup of the invention, the center of a laser beam incident on a dichroic prism can easily correspond to the center of an objective lens by a heat sink, which is held by a boss portion inserted into a through hole provided in an optical base and a boss plate having a plane portion in which the boss portion can be moved in the through hole in a direction orthogonal to an axis line of the boss portion.

Abstract: A method for correcting recording positions of light beams scanned by a light beam scanning apparatus, in which at least one of plural light beams is deflected by an optical deflecting device and all the plural light beams are combined and scanned by a common scanning optical system. The beam position correction data for the optical deflecting device for keeping positions of the light beams constant is obtained by detecting the beam positions before the scanning optical system. The recording positions of respective light beams on a recording surface is also detected to obtain an additional correction data for correcting deviations of the recording positions due to uneven optical power distribution of the light beam or astigmatism of the scanning optical system. The additional correction data is added to the beam position correction data to obtain the final correction data, by which the optical deflecting device is controlled.

Abstract: A monolithic optical pickup has all passive optical elements aligned during fabrication, thereby requiring no alignment during the assembly of a system utilizing it. Its supporting structure is the monolithic passive device itself. A single surface incorporates all the functions of an optical pickup system including a focusing element, image creation apertures and stops, scattering/reflection reduction, and return path apertures and optics. The elements are formed from a metalized layer which is applied lithographically. Placing the apertures and stops on the principal plane of the focussing element allows for the image size to be precisely controlled by the image distance. The monolithic optical pickup is well suited for use with multiple detector elements. Alternate embodiments of the invention may omit some of the optical system elements.

Abstract: An optical disc recording and reproducing apparatus is provided. The apparatus detects the level of a focus error signal output from an optical pickup and a peak of the focus error signal occurred before the focus is obtained while an objective lens of the optical pickup moves in the focusing direction, discriminates a type of the loaded optical disc based on a first reference level or a second reference level, and actuates a focus servo before the objective lens moving in the focusing direction reaches a focalized position. Thus, a read only disc or a recordable disc can be rapidly reproduced.

Abstract: An integrated unit in which a light source and a light emitting diode are combined into one component is fixed to an optical bench. Then, relative position adjustment of an objective lens actuator is carried out with respect to the optical bench so that a desired detection signal can be obtained through reflected light from a disk information recording medium and then the objective lens actuator is fixed. The relative position adjustment of the integrated unit is no longer required and it is no longer necessary preliminarily to provide a margin for adjusting the integrated unit. Thus, an optical head can be reduced in size and thickness.

Abstract: A Cartesian scanning system for scanning a surface of a sample. The scanning system includes a light source assembly configured to produce at least one collimated beam of light, a light sensing system, a stage configured for mounting the sample thereon and a linear track having a direction of elongation. The linear track and the stage are configured to move relative to each other. The scanning system also includes a scanning head having a reflecting system which is configured to direct the collimated beam of light onto the surface and to direct a beam of light reflected from the surface to the light sensing system. The scanning head is slidably associated with the linear track so as to be moveable in a direction parallel to a direction of elongation of the linear track. Also included are a position determination system and a scan displacement correction system.

Abstract: A focus servo control is performed by changing a condition of a focus servo loop from an open condition to a close condition in correspondence with a level of a reflection light signal, which is obtained as a reflection light of a light beam reflected from an information record medium is detected by a light receiving element such as an optical pickup.

Abstract: A device for refracting beams of light, in particular laser beams, with at least one refraction component which can be adjusted by means of a drive unit. The drive unit is formed from the drive of a read/write head of a magnetic data storage component.

Abstract: A process for a master optical disk of the present invention is a process for a master optical disk having a physical format in which in a groove-and-prepits-included rewritable optical disk, prepits not being on spirals identical to those of a groove, for example, prepits shifted outward and inward by a half-track pitch from the groove center, are recorded, wherein an acoustooptic-effect-used optical deflector or a field-optical-effect-used optical deflector 101 is disposed on an optical path of a mastering apparatus so that a single laser beam is deflected. This process makes it possible to use a single processing scan to perform laser processing for a plurality of arbitrary points, for example, the center of the groove, and positions shifting inward and outward by a half-track pitch from the center.

Abstract: A wire-suspended objective lens actuator structure and a method of assigning current pathways. The lens holder on the actuator structure has a group of focusing coils, a group of tracking coils and a group of slant adjustment coils. The coils are connected to four conductive wires. A first conductive wire controls the focusing coil and a second conductive wire controls the tracking coil. Similarly, a third conductive wire controls the slant adjustment coil. The ground terminals of all three groups of coils are connected in parallel to a fourth conductive wire. The fourth conductive wire serves as a common ground terminal. The control terminal of each group of coils is connected to a differential voltage-output current amplifier circuit or a differential voltage-output voltage amplifier circuit. Hence, the focusing, the tracking and the slant adjustment coils can be driven by differential voltages.

Abstract: On an optical disc including a substrate on which pits having at least two different depths are formed, main information is recorded by the shape of the pits and additional information is recorded by the depth of the pit. It is possible to reverse polarity of a tangential push-pull signal dependent on the depth of the pit, and therefore it becomes possible to record information utilizing the depth of the pit. This improves recording density of the optical disc. Further, when information of the optical disc is to be copied, the information recorded by the depth of the pit cannot be copied. Therefore, unauthorized reproduction can be prevented.

Abstract: This optical disk device includes an objective lens (7) for condensing radiated light from a light source on an optical disk (8), an optical detecting unit for detecting reflected light from the optical disk (8), and a control unit for performing the tracking control and/or the tilt control of the objective lens (7) by utilizing the output from the optical detecting unit, in which the control unit uses the off-track quantity and/or the tilt quantity of the objective lens (7) when performing the above described control.

Abstract: In a control apparatus for operating with program data, it is possible to alter the operation of a control circuit by rewriting the data of the program memory built in an LSI, with ease and at a low cost independently of the operation of the control circuit. For that purpose, the control apparatus includes a ROM, a SRAM, a means for writing data in the SRAM, a selection means for selecting the output from the ROM or the SRAM in accordance with the addresses supplied to the ROM and the SRAM, and a control means for outputting the addresses to the ROM and the SRAM and operating with the output from the selection means as program data.

Abstract: An optical disk is provided for recording data of a signal modulated according to a predetermined modulation method in a form of concavo-convex pits. The optical disk includes a first area having a reflecting film partly removed, and a second area for recording pits which are different from pits satisfying requirements of the predetermined modulation method. The first area having the reflecting film partly removed includes a portion which is formed by removing the reflecting film, and has a length longer than a maximum pit length determined by the modulation method in a circumferential direction of the optical disk. When the pits recorded on the optical disk are physically copied as they are, physical copying of the optical disk can be prevented by utilizing such a difference that the authorized optical disk differs from a pirated copy in a combination of the respective reproduced signals of the first and second areas.

Abstract: There is disclosed an optical pickup apparatus in which an optical axis of an objective lens can be kept perpendicular to a recording surface of an optical disk regardless of a warp or a curvature of the optical disk. In this optical pickup apparatus, a lens holder can be moved in a focusing direction and a tracking direction. In order that the objective lens can be tilted in accordance with a skew of the optical disk in a radial direction, second magnets are mounted on the lens holder whereas second coils are mounted in opposed relation to the second magnets, respectively. The second magnets and the second coils cooperate with each other to tilt the objective lens.

Abstract: An optical memory apparatus has an offset inserting unit for inserting a predetermined offset to the focus error signal, and a focus servo pull-in determining unit for inserting, when the focus servo control unit executes focus servo pull-in, offset to the focus error signal, detecting level change of the focus error signal and determining success or failure of focus servo pull-in.

Abstract: An optical pickup assembly includes an optical pickup unit (OPU) and a flex circuit. The OPU is mounted atop a thermally conductive plate through a cutout of the flex circuit. Bond wires couple contacts pads on the OPU and the flex circuit. Alternatively, OPU is mounted atop the plate and the plate is mounted atop the flex circuit. The plate includes a cutout where bond wires pass through to couple the contact pads on the OPU and the flex circuit.

Abstract: A position control apparatus of an optical system capable of positioning a lens at a high accuracy in a near-field optical system using a solid immersion lens. An objective lens 2 and a solid immersion lens are fixed to a lens holder 4. The lens holder 4 is moved by a tracking actuator 5 in the tracking direction of an optical disk 51 and is moved by a focus actuator 8 in the focus direction. The focus actuator 8 is controlled on the basis of the electrostatic capacitance occurring between the solid immersion lens 3 and the optical disk 51.

Abstract: An optical pickup that is equipped with a photodetector unit, irradiates an optical disc with a laser beam, and receives returning light reflected by the optical disc, where the optical pickup is constructed to (1) divide the laser beam into a main beam, a preceding sub-beam, and a succeeding sub-beam, (2) direct the main beam, the preceding sub-beam, and the succeeding sub-beam toward the optical disc, and (3) divide returning lights of the main beam, the preceding sub-beam, and the succeeding sub-beam respectively into first-fourth main returning lights, first-fourth preceding returning lights, and first-fourth succeeding returning lights, and the photodetector unit includes: first-fourth main photodetectors that respectively receive the first-fourth main returning lights; first-fourth preceding photodetectors that respectively receive the first-fourth preceding returning lights; and first-fourth succeeding photodetectors that respectively receive the first-fourth succeeding returning lights.

Abstract: An optical pickup position control method that uses a stepping motor to control the position of the optical pickup, and that makes it possible to reduce the out-of-step noise generated from the motor and to accurately position the optical pickup, has a first procedure that gives the motor a control command to move the optical pickup in the direction toward the maximum feed position by a feed amount that is smaller than the maximum feed amount from base position to the motor's maximum feed position; a second procedure that gives the motor a control command to move the optical pickup in the direction toward base position by the maximum feed amount; and a third procedure that gives the motor a control command to move the optical pickup in the direction toward maximum feed position by the center position feed amount from base position to center position.

Abstract: According to the present invention, an optical pickup device forms one main spot, a first subspot, and a second subspot by irradiation of light on an optical disk having a groove part and a land part. The optical pickup device includes operation circuits which indicate a deviation between each of the optical spots and a track, and &agr; detecting means for detecting such an &agr; value that a difference in absolute value between SPP1 and &agr;SPP2 falls in a preset range, where an AC amplitude of a push-pull signal of the first subspot is SPP1, and an AC amplitude of a push-pull signal of the second subspot is SPP2, wherein SPP1-&agr;SPP2 (&agr; is a constant) is a land/groove discriminating signal. With this, in the optical pickup device for recording and reproducing information on/from the optical disk having a land/groove part, it is possible to generate a land/groove discriminating signal and a tracking error signal without an offset, thereby performing excellent tracking control.

Abstract: A magnetic tape comprises a substrate having on one side thereof a magnetic layer serving as a recording surface, and on the other side thereof at least two layers containing inorganic particles which serve as a non-recording surface, wherein said magnetic tape has a region on the side of the non-recording surface along the longitudinal direction of the tape in which a regular pattern for servo tracking having different optical properties from the other major region of the side of the non-recording surface is or can be formed. The layers on the non-recording surface are characterized in that the inorganic particles in the outermost layer are larger than the inorganic particles in the underlying layer(s).

Abstract: A method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus.

Abstract: Servo control circuitry 300 includes a digital to analog converter 402 for converting digital servo control data into a pulse width modulated signal. A first conductor transmits the pulse width modulated signal to an external device 409. A second conductor transmits a reference signal derived from the clock signal to external device 409, external device 409 differentially receiving the pulse width modulated signal with respect to the reference signal.

Abstract: US vi A calibration of input signal offsets for stray light in an optical disk drive is presented. The input signal offsets can be determined by setting a laser power level, receiving digitized input signals, and setting the input signal offsets so that the digitized input signals are zero. The laser power level can be a read power or a write power. In some embodiments, input signal offsets for both read power and write power are determined and stored.

Abstract: A multilayer optical information storage medium, such as a card, uses a luminescent, fluorescent, or electroluminescent material to reproduce information in the form of incoherent radiation. Each layer has multiple pages of information. A specific page on a specific layer is addressed by moving the card relative to a read head so that the image of the specific page to be read is focused on the read head. This can be accomplished by moving the card in the X, Y, and Z directions, or by holding the card stationary and by moving a two-dimensional image detector in the X, Y, and Z directions.

Abstract: A device for reading from and/or writing to optical recording media, the device comprising a light source for producing a scanning beam, a photodetector for detecting the scanning beam reflected by the recording medium and a semi-transparent mirror arranged in the beam path for directing the scanning beam onto the recording medium and the reflected scanning beam onto the photodetector. An object of the invention is to improve a device of this type, in particular with regard to reducing the production costs. This object is achieved by the semi-transparent mirror being a plane-parallel plate with a layered structure, and a partially reflective layer being arranged between two small carrier plates.

Abstract: A tracking error balance adjustment circuit, and a current control circuit used for a variable gain RF amplifier automatically controlled to output a signal having a predetermined amplitude. The tracking error balance adjustment circuit comprises two separate gain adjusting circuits, each having variable attenuation circuit having first gm amplifier of variable gm type, a second gm amplifier of variable gm type connected to the variable attenuation circuit, and an output circuit connected to the second gm amplifier, comprising an operational amplifier circuit having feedback resistor, wherein the first and second gm amplifiers are differentially controlled commonly by a control current.

Abstract: In an optical disk drive, in order to cancel a lens offset which may occur when performing a seek followed by read, a seek position must be set several sectors before a target position to read, resulting in a delay in access time.

Abstract: Address groups are composed of two of address blocks 16, 17, 18, and 19, where the address blocks 16, 17, 18, and 19 are disposed in a sector address region 5 and include identifiable information of address numbers 13 and overlapping sequential numbers 14. The address groups are disposed so that each group is alternately shifted from a track center 2 toward the inner periphery side or the outer periphery side, by a width substantially equal to half the track pitch, along the radius direction.

Abstract: In accordance with the invention, an optical head device comprises a light source, a light receiving element, an optical system that guides light emitted by the light source to an optical recording medium and also guides the light reflected from the optical recording medium to the light receiving element and a base on which the light source, the light receiving element and optical elements constituting the optical system are mounted. An element holder composed of a photosensitive glass is mounted on the base. The element holder has a positioning portion(s) therein for at least one of the optical elements. The base has openings therein at locations through which the optical elements can be assessed from the back thereof.

Abstract: An optical storage medium and a reading device are proposed, wherein the optical storage medium has the format of a credit card.

Abstract: A recording media for recording/reproducing information by using an near-field, overcoming a diffraction limit, and having an ultra-high recording density, and a fabrication method thereof, and a recording/reproducing device are disclosed. The optical recording medium includes a planar aperture array which can generate the near-field light, an information recording layer, and a spacer maintaining a predetermined gap between the planar aperture array and the recording layer, the gap being sealed from an external environment. The optical recording/reproducing device is controlled by a macro-servo and a micro-servo, thereby recording/reproducing the information by using the planar aperture array thereof. As a result, the present invention overcomes a diffraction limit, achieves the ultra-high recording density, and thus records a large amount of information even on the small area.

Abstract: An apparatus and method for generating a radio frequency (RF) signal and control signals are provided. In an apparatus for generating a radio frequency (RF) signal and control signals in which the current output from a plurality of light receiving elements is converted into voltage signals and the RF signal and the control signals are generated in response to the voltage signals, the apparatus includes an input data processing unit, a digital filter, a servo signal generating unit, a digital RF data generating unit, and a reference comparator. The input data processing unit performs time-sharing sampling on the voltage signals and converts the voltage signals into first digital signals in response to an analog/digital conversion clock signal having a predetermined period and a sequentially applied selection signal. The digital filter filters each of the first digital signals to modify the shape of the waveforms of the first digital signals and outputs the modified waveforms as second digital signals.

Abstract: The present invention provides a method for guiding a pick-up head to follow an information track. The method comprises the steps of sensing and sending notification of displacement between the pick-up head and the center of the information track, generating a first correction directly proportional to the displacement, generating a second correction non-proportional to the displacement and generating a driving force proportional to the sum of the first and second correction, driving the pick-up head to follow the information track.

Abstract: Apparatus for reading and/or writing onto an information carrier includes the positioning system. The positioning system includes a drive member for moving a second part with respect to a first part and a fine-positioning member for moving a third part with respect to the second part. The positioning member also includes control means for continuously controlling the drive member in response to the orientation signal. The control means include control signal generating means for generating a control signal from the orientation signal. The control means further include a sensor for generating an auxiliary signal which is an indication for a current consumed by the drive member, and signal combination means for generating a drive voltage for the drive member in response to the control signal and the auxiliary signal.

Abstract: First and second magnetic layers are laminated though a tunnel barrier layer, wherein a region is formed in which change in a magnetic resistance ratio with respect to change in a voltage applied in such a manner that the second magnetic layer has a lower potential as compared with the potential of the first magnetic layer is smaller than change in a magnetic resistance ratio with respect to change in a voltage applied in such a manner that the second magnetic layer has a higher potential as compared with the potential of the first magnetic layer. Voltage is applied to the magnetic tunnel device in such a manner that the potential of the second magnetic layer is lower than that of the first magnetic layer so that dependency of the magnetic resistance ratio on the voltage is reduced. Thus, a stable tunnel current flows.

Abstract: A optical disk drive determines an optimum radiating power of laser for recording data in accordance with an asymmetry value or amplitude of a read signal. The optical disk drive includes an offset controller for changing a focus offset of laser in a direction of an optical axis to a focal point on an optical disk, a pre-test data recorder for recording pre-test data in a trial write area provided on the optical disk with the laser having a power kept in constant while the focus offset is changed by the offset controller, an offset detector for detecting a focus offset that minimizes an asymmetry value of a read signal of the pre-test data, a power controller for recording an Optimum Power Control (OPC) test data in the trial write area while changing the power of the laser, and an OPC operator for determining an optimum power of the laser in accordance with an asymmetry value of a read signal of the OPC test data.

Abstract: An optical recording/reproducing apparatus includes an optical pickup and a signal processor. The optical pickup includes an optical splitting device which splits light emitted from a first light source into a main light beam and sub-light beams which are symmetrical with respect to the main light beam and irradiates the split light beams on a recording medium, and a light detection device which receives the main light beam and the sub-light beams reflected by the recording medium, so as to detect a tracking error signal in a three-beam method and one of a push-pull method and an improved push-pull method.