Abstract: In a disk unit including a plurality of disk media of which any one surface is a servo surface and the other surfaces are all data surfaces; a servo head and data heads arranged on the servo surface and the data surfaces; a positioning mechanism for positioning the servo head and the data heads on desired tracks; and a control unit for controlling the positioning mechanism; the control unit reading servo data from the data surfaces and updates them to find offtrack compensated data, and the head positioning operation being controlled by using the offtrack compensated data and servo information on the servo surface, an offset occurring in the disk unit is compensated by setting the servo track center of the servo head as a reference for positioning the head; writing a pair of servo data for positioning the head onto said data surface while giving a predetermined offset amount which is offset from said track center; giving a predetermined offset amount to thus read and measure the pair of servo data and using t

Abstract: An apparatus and method for providing a sampled tracking error signal in an optical system using multiple illumination spots. An optical source generates radiation which is applied to a storage medium to produce a first illumination spot, a second illumination spot and a third illumination spot thereon. A return beam resulting from application of the radiation to the medium is detected, and a data signal is generated from the detected return beam. A sampled tracking error signal is generated from a first sample of the data signal, taken when the second spot illuminates a portion of a tracking mark, and a second sample of the data signal, taken when the third spot illuminates another portion of a tracking mark. The data signal samples may be normalized to samples of a source monitor signal. The data signal may be generated from magneto-optic, write-once, or other types of optical storage media.

Abstract: A head records a track (e.g. a servo track) in a memory member outside of a clean room without using reference indices. In each of a plurality of cyclical movements (e.g. revolutions), signals (e.g. servo signals) are recorded in the track in an individual number of frames. Thereafter the distance of the unrecorded portion of the track is determined. In the next cyclical movement, the head records signals in an individual number of frames contiguous to the frames previously recorded, in a track distance dependent upon such individual number relative to the number of frames still unrecorded and upon the distance determined for the unrecorded track portion. In a last cyclical movement, the head records a single frame in a particular spatial relationship with the first and last frames. In a specific embodiment, 2.sup.N-K frames may be recorded in the K cyclical movement. Additional signals may thereafter be recorded by the head in tracks in a single cyclical movement.

Abstract: A VISS circuit for preventing image search malfunction occurrence due to variation in the speed of a video tape used in a video cassette recorder makes it possible to carry out a normal VISS operation by utilizing the pulse width of the Schmitt trigger pulse, which is varied in accordance with the change in speed of the video tape. The circuit includes a Schmitt trigger circuit capable of varying the width of the Schmitt trigger pulse in accordance with variation of upper and lower extreme voltage values of a control signal based on the speed signals after detecting the tape speed signals at the time of the recording and the control signals from the control head, the varied width of the Schmitt trigger pulse being supplied to a VISS operation circuit, and a control device for supplying a signal for varying the width of the Schmitt trigger pulse produced by the Schmitt trigger circuit in accordance with the tape speed.

Abstract: An objective lens driving biaxial actuator for driving an objective lens in both a focusing direction and a tracking direction with respect to a recording medium. The biaxial actuator comprises: a movable portion for holding the objective lens; an elastic member having its one end attached to the movable portion for movably supporting the movable portion; a stationary portion fixing the other end of the elastic member; and a balancer disposed at the side of the stationary portion with respect to the objective lens and carried on the movable portion at such a distance that its clearance from the stationary portion may restrict the deformation of the elastic member within an elastic limit. A hinge is interposed between the elastic member and the movable portion for moving the objective lens in the tracking direction.

Abstract: A rotary head tape recording and reproducing apparatus drives a rotary drum and a capstan by a common driving motor. In the reproducing mode, rotary heads generate a scanning position detection signal by picking up an address signal indicating the current scanning position from the recording track, and the driving motor is controlled so as to match the scanning position detection signal with a reference scanning position signal.

Abstract: The present invention relates to a gear assembly which comprises an eccentric member having a first cylindrical portion with a first center axis in accordance with a center axis of said eccentric member for receiving said shaft on a front side thereof fronting said motor, and a second cylindrical portion with a second center axis on a back side thereof, said second center axis being eccentrically disposed with said first center axis; a pinion gear equipped with a radial ball bearing in its center, having a first hole, a second hole opposing said first hole, a first number of teeth and a first diameter, said first and second holes being parallel with a center line thereof and said said radial ball bearing being inserted into said second cylindrical portion; With the structure of the gear assembly for a pickup unit feeding apparatus, it is permitted to miniaturize the size of a pickup unit feeding apparatus as well as to exactly control the pickup unit.

Abstract: A system for detecting the servo sectors of a rotating magnetic disk solely from read pulses representative of information read on the disk. Each servo sector has a first or intersector gap, an automatic gain control data zone, a second gap, and a track data zone. Sector pulses indicative of the servo sectors are generated when all these gaps and zones are detected. Preferably, for the production of a write enable signal, the sector pulses thus produced are further compared with window pulses obtained by imparting a prescribed delay to the sector pulses. Writing on the disk is enabled when the sector pulses agree in time with the window pulses.

Abstract: A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions.

Abstract: An image signal recording and reproducing apparatus comprises a head array having a plurality of head gaps for recording and reproducing the image; a piezoelectric actuator having a polarization direction and for moving the head array downwards and upwards in a width direction of a track in accordance with input of a driving voltage; a phase comparator for generating a phase control signal in accordance with a phase difference between the head array and the track; a unit for outputting the driving voltage to the actuator in accordance with the phase control signal; and a signal processing unit for recording and reproducing the image signal on and from the track by the head array.

Abstract: An optical pickup is adapted for recording and/or reproducing signals by radiating a light beam from a light source on an optical recording medium via an object lens. The optical pickup includes a light receiving device for receiving a return light from the optical recording medium, and a focusing error detecting unit for detecting an amount of deviation of the focal point along the optical axis. The measurement of a focusing error is based on signals from the light receiving device. The optical pickup further includes an electrostriction device arranged on a path of light outgoing from the light source to the optical recording medium and having a central section and a peripheral section exhibiting a phase difference from each other depending on an applied voltage.Focusing errors may be detected with high accuracy with the optical pickup. A focusing servo device compensates for the focusing error detected by controlling the focal point along the optical axis using a focusing servo device.

Abstract: A digital compensator controls a servomechanism, such as the focus servo of an optical disk drive. The compensator waits one full sample period before applying the correction that was calculated for the proceeding sample. The compensator does not use the present input sample in its calculation of the present output sample. The method for operating the digital compensator comprises the steps of receiving a first input sample at time t.sub.1, receiving a second input sample at time t.sub.2, and computing a first output in response to the first input sample at time t.sub.2. The method does not require a present input sample to calculate a present output.

Abstract: A reading device (6) and an optical record carrier (5) having at least two information planes (1, 2, 3). The radiation from the record carrier is converted in a detection system (15) into a detection signal (16) which is applied to a detection circuit (17). In order that this circuit can derive the read information from the detection signal in a reliable manner, the interference signals generated by the information planes which are not to be read should comply with a requirement, referred to as the interference requirement, which is characteristic of the detection circuit. Values for the parameters of the record carrier, such as the thickness of the layers between the information planes and the reflection and transmission coefficients of the information planes then follow from this interference requirement.

Abstract: A data write apparatus includes a card conveyor path, a recording head, a sensor circuit, a Central Processing Unit (CPU), a drive circuit, and an enable section. A magnetic card is conveyed in the card conveyor path. The recording head is arranged on the card conveyor path and performs a recording operation on the magnetic card by energizing a winding coil. The sensor circuit is arranged on the card conveyor path near the recording head and detects the magnetic card conveyed in the card convey or path to output a detection signal. The CPU outputs write data to be written on the magnetic card in response to the detection signal from the sensor circuit. The drive circuit energizes the winding coil of the recording head on the basis of the write data from the CPU to perform the recording operation.

Abstract: A method and apparatus for detecting peaks in a signal which comprises an alternating polarity waveform including a plurality of points. A selected point in the signal is designated. Thereafter, a threshold value for the selected point is established utilizing a prior threshold value associated set off with spaces with a point prior to the selected point as follows:(m(n)=t0*ax(n)+t1*m(n-1))wherein n is the point identifier, m(n) is the threshold value, t0 is a fixed positive constant less than one, t1 is a fixed positive constant less than one, ax(n) is the absolute value of the input signal, and m(n-1) is the prior threshold value for the prior point. In this manner the threshold value may be adjusted for fluctuations in amplitude of the signal. Next, the selected point is compared with the threshold value to determine whether or not the selected point is within a predetermined distance of the threshold.

Abstract: An information recording, reproducing apparatus comprising a first operation switch, a memory for storing a plurality of operation modes with operation steps for controlling the information recording, reproducing operation with the instructions from the control apparatus, a selecting apparatus for selecting a selecting mode, and a switching apparatus for selecting one operation mode from among the plurality of operation modes, where selection of an operation mode among from the plurality of operation modes is performed after a selection mode has been selected.

Abstract: A magnetic head loading/unloading apparatus has a head arm being maintained in either a loading state or an unloaded state by means of a permanent magnet. The head arm has a magnetic head on one end thereof, and is fixed on an end of a first yoke. A second yoke is arranged parallel to the first yoke, and is rotatable on the first yoke. A touching member is fixed on the second yoke, the touching member pressing a bottom surface of the head arm so as to elastically deform the head arm so that the magnetic head is positioned in an unload position. A permanent magnet is provided on the first yoke and a coil is provided on the second yoke. When the second yoke is moved to a first position, the head arm is elastically bent by a pressing force exerted by the contacting member so that the magnetic head is positioned in an unload position. When the second yoke is moved to a second position, the contacting member is apart from the head arm so that the magnetic head is in a load position.

Abstract: A drive circuit having two electronic switches formed from N-MOS transistors is designed to alternatively connect the input of a preamplifier stage to a first or second read sensor on the read head of a magnetic tape. The drive circuit also has a third electronic switch formed from an N-MOS transistor which grounds the input of the preamplifier stage. Based on logic input signals, a control circuit switches the first and second switches, or closes the third switch and simultaneously opens the first and second switches.

Abstract: In an optical disk apparatus, an optical head is moved in a radial direction of an optical disk having a track spirally or concentrically formed in a state that a groove and a land are adjacent, and detecting device for detecting reflected light from the optical disk, and a track error signal, which is obtained by detecting light from the optical disk along with the movement of the optical head, and a track addition signal are generated, a signal A showing a central position of a groove, a signal C showing a central position of a land, signals B and D showing a groove-land changing position are generated based on the track error signal and the track addition signal, and a direction of the movement of the optical head is detected in accordance with the generation order of the signal A showing a central position of a groove, the signal C showing a central position of a land, and the signals B and D showing a groove-land changing position.

Abstract: A disc reproducing apparatus for an optical disc on which data is recorded. The reproducing apparatus reproduces data recorded on the disc as reproduced data, and, in response to a user input, performs data retrieval, a process in which the data to be reproduced from the disc is selected. The apparatus comprises a main body section and a display, attached to the main body section, for displaying reproduced data. The main body section includes an optical pickup that provides signals in response to the disc, a signal processing circuit that processes the signals from the optical pickup means to provide reproduced data, a feed motor that moves the optical pickup radially relative to the optical disc, and a feed motor control that controls the feed motor. The main body section also includes a device that rotationally drives the optical disc, and an input device that receives the user input. Finally, the main body section includes a control device that includes a single central processing unit.