Abstract: An apparatus for changing a record comprising a record changing fork comprising first and second spaced apart tines arranged in a record plane and extending from a fork base to a fork mouth, each tine comprising a groove extending from the fork mouth at least part way to the fork base, the grooves being arranged to hold a record therebetween in the record plane; at least one tine comprising a resiliently deformable record gate, the record gate being adapted to prevent sliding of a record in the grooves past the record gate unless the record is slid with a force exceeding a threshold force; at least one shelf adapted to support a record, the width of the shelf being less than the separation between the tines; and, a control mechanism connected to the record changing fork.

Abstract: A motor driving assembly includes a motor. The motor includes an outer housing, and a rotor and a brush holder received in the outer housing. The rotor includes a rotary shaft extending out of the outer housing. A commutator is fixed on a shaft portion of the rotary shaft within the outer housing. Brushes for contacting the commutator are disposed on the brush holder. A visible identification mark fixed relative to the rotary shaft is disposed outside the outer housing of the motor, such that a relative position between the brushes and the commutator in a rotational direction of the rotary shaft is identifiable by reference to a position of the visible identification mark relative to the outer housing in the rotational direction of the rotary shaft. As such, the commutator can be prevented from stalling at a position where arcing noise may be easily generated.

Abstract: A recording device includes: a recording and reproducing unit that records or reproduces data stored on a recording medium; and a control unit that interrupts recording during recording performed by the recording and reproducing unit, acquires an evaluation value of a recording quality of a recorded portion, changes recording speed based on the evaluation value, and resuming the recording.

Abstract: When record or reproduction quality of an optical disc is deteriorated, an enhancement in the performance is implemented by slowing down record or reproduction speed of the optical disc. However, there still exists a problem of how to select and determine a timing with which the speed is to be modified. In the present invention, the modification of the speed is performed with a seek processing selected and used as its trigger, and depending on various conditions at that time. Simultaneously, information recording area of the optical disc is separated into a plurality of zones. Then, when an optical pickup passes though a zone switching portion therebetween, the seek processing is inserted, thereby being used as the trigger for the speed modification.

Abstract: The device for displaying time in selectable display patterns includes a storage device, an interface, a housing, display elements, and a controller. The storage device stores selectable display patterns. The interface receives an input to select a display pattern. The housing contains a display area that displays the selected display pattern. The display elements may include hour display elements, minute display elements, second display elements, day display elements, date display elements, and/or month display elements. Time is displayed by the amount of display elements in the exhibiting state.

Abstract: A recording method for an optical disk drive is implemented as follows. First, at least one of the level of the focusing error signal, the level of the tracking error signal, a wobble synchronization pattern loss, the error rate of demodulating a wobble signal and the frequency of buffer under-run occurrence is detected. If at least one detected value exceeds the preset value, the recording will be ceased. Then, the rotation speed of the optical disk drive is decreased, and the recording is resumed with the decreased rotation speed.

Abstract: A method for determining the position of an optic pick-up head and the device of the same are disclosed. The number of frames in certain section of the disk are used to determine the position of the optic pick-up head. The number of frames in inner section of the compact disk is smaller than that in the outer section. The disk is virtually divided into a plurality of sections, and number of frames within each section is defined. As a result, when the optic pick-up head is at a certain frame, the position of the optic pick-up head can be determined the number of frames in the section.

Abstract: A disc-like record carrier has a machine-readable information track in which is provided record carrier control information including the actual physical diameter of the carrier.

Abstract: A disc-like record carrier (1) has control information recorded. The control information comprises diameter information which is indicative of the diameter of the record carrier. An information recording and/or reading apparatus involves a drive structure for rotatingly driving the disc-like record carrier. The apparatus includes a control unit which adapts the loop gain of a control loop for controlling the number of revolutions per minute of the record carrier in dependence on the control information recorded on the record carrier.

Abstract: An apparatus and method for detecting rotational vibration applied to a disc drive having an actuator supporting a head adjacent a rotatable disc. A spindle motor has a set of driver coils which rotate the disc through electrical commutation, and a set of velocity sense coils which sense the rotational velocity of the motor in relation to voltages established across the sense coils. Rotational vibration is detected in relation to changes in the rotational velocity of the disc. A data transfer operation between the disc and a host device is interrupted when the magnitude of the rotational vibration exceeds an acceptable level. A servo circuit compensates for the application of rotational vibration to the disc drive by adjusting current applied to the actuator in relation to the changes in the rotational velocity of the disc.

Abstract: The present invention provides an improved disc drive. In one embodiment of the present invention a disc drive capable of spinning a disc, which contains more than one type of data is disclosed. A first type of data is associated with a first speed, and a second type of data is associated with a second speed that is faster than the first speed. The disc drive includes a drive mechanism, which may spin the compact disc at the first and second speeds and retrieve data from the compact disc at either speed. The disc drive also includes an elastic buffer, which is in communication with the drive mechanism. The buffer receives data from the drive mechanism at a variable input data rate and outputs data at a variable output data rate. Whereby when the drive mechanism spins the compact disc at the second speed the buffer may receive the first type of data without causing the drive mechanism to slow down to the first speed, and the buffer may output the first type of data at the variable output data rate.

Abstract: In a method of starting rotation of a magnetic disk medium of a large-capacity flexible disk by a spindle motor for use in a high-density type flexible disk drive for carrying out data recording and reproducing operation to and from the magnetic disk medium of the large-capacity flexible disk which requires to rotate at a high rotation speed on recording and reproducing, the method includes: a first step of rotating the spindle motor at a low rotation speed lower than the high rotation speed on rotation starting of the magnetic disk medium; a second step of rotating the spindle motor at the high rotation speed subsequently to rotating of the spindle motor at the low rotation speed; a third step of rotating the spindle motor at the low rotation speed subsequently to rotating of the spindle motor at the high rotation speed; and a fourth step of rotating the spindle motor at the high rotation speed subsequently to rotating of the spindle motor at the low rotation speed at the third step.

Abstract: A spindle motor of a disk drive is controlled in a switched voltage mode. A power bus supplies a voltage to the spindle motor. The power bus voltage is subject to variations while the spindle motor is being driven. An uncompensated motor voltage signal is modified to provide a compensated signal having a modified duty cycle. The modified duty cycle is inversely proportional to the variations in the power bus voltage. Commutation logic uses the compensated signal to generate commutation commands, which cause a power driver stage to energize the windings of the spindle motor.

Abstract: A method is disclosed for measuring the linear velocity of recording of data recorded a CD using a Hall sensor. A Hall sensor is placed in the spindle motor of a CD drive to produce a signal based on alternating magnetic flux in the spindle motor. An amplified and processed version of the signal output from the Hall sensor during operation of the CD drive is monitored to measure the timing of three successive inversions of the signal. Based on this timing measurement, the rotational speed of the spindle motor is determined. The recording linear velocity of the data recorded on the CD presently mounted in the CD drive is obtained based on the rotational speed determined from the Hall signal and on a reference rotational speed. As a result of using this method for obtaining the recording linear velocity of the data recorded on the CD, no errors are generated based on the number of tracks the pickup is moved across, and the time necessary for measuring the recording linear velocity is reduced.

Abstract: A method for controlling speed of a spindle motor within a disk player is provided. The spindle motor drives a disk thereon and the disk player includes a pickup and a control circuit for performing focus and tracking operation of the pickup. The first step of method is to determine an allowable spin speed, Va, in accordance with a predetermined manner. The second step is to set speed of the spindle motor to operate at an allowable speed Va. The third step it to test if out-of-focus occurs during seeking of a particular track. If Yes in step 3, the fourth step is to re-focus the pickup. The fifth step is to set Va=Va- a predetermined decrement. The sixth step is to set speed of the spindle motor to operate at current Va decreased speed.

Abstract: A method for controlling the speed of a motor driven by an unregulated voltage supply is disclosed. The disclosed method comprises obtaining a ripple signal (V.sub.R) representative of the ripple component of the supply voltage, and modulating the motor current (I.sub.M) in response to at least the ripple signal to maintain the speed of the motor at a prescribed target speed.

Abstract: A method of discerning an optical disk in a compact disk drive which includes the steps of moving an optical pick-up device to a table of contents (TOC) region of an optical disk to perform a focusing operation for reading data from the optical disk, and discerning whether an optical disk is loaded on a turntable of the compact disk drive. When the optical disk is loaded in the compact disk drive, the loaded optical disk is rotatably driven by a spindle motor. The time necessary for the rotating speed of the optical disk to reach a predetermined speed is counted, and the counted time is then compared with a predetermined time to determine whether the optical disk is one of a first type having, for example, a eight centimeters diameter and a second type having, for example, a twelve centimeters diameter. If the counted time is less than the predetermined time, the loaded optical disk is determined as a eight centimeters disk. If, on the other hand, the counted time is not less than the predetermined time, i.e.

Abstract: A motor speed regulating circuit includes a speed signal generator for generating a speed signal having a frequency proportional to the speed of the motor, synchronously with the rotation of the motor. A time difference detector is used for detecting a time difference between the period of the speed signal and a predetermined standard time. A control voltage generator is used for generating a speed control voltage to be applied to the motor in accordance with a detected time difference and feedback-controlling the speed of the motor in accordance with the standard time. A starter is used for starting the motor after the motor is stopped. The motor can be reliably restarted after it has been stopped.

Abstract: A disk playback apparatus designed such that the linear velocity of the disk is stabilized during a short period corresponding to one to several revolutions of the disk and occurrence therein of vibration and noise is suppressed is disclosed. The apparatus is characterized in that the revolving axis of the turntable on which the disk is mounted is driven by a low-torque spindle motor and the wheel effect of the revolving axis or the spindle motor is made larger.

Abstract: A track jump control circuit having a pick-up for reading information stored on a disc, a motor for moving the pick-up in a radial direction of the disc, a speed detector for detecting the moving speed of the pick-up and for outputting a speed signal, an integration circuit for generating a signal according to the moving amount of the pick-up according to the speed signal being detected, a reference voltage generation circuit for generating a reference signal according to the distance for which the pick-up is moved in a track jump mode, a comparator for comparing the reference signal with the signal according to the moving amount and for sending a difference signal to the motor, and a controller for stopping sending the difference signal to the motor when the difference signal is in a predetermined range. When the difference signal between the reference signal and the signal according to the moving amount is in the predetermined range, the completion of the track jump operation is determined.

Abstract: An apparatus for rotationally driving an optical disk in an optical disk recording and/or reproducing apparatus capable of recording or reproducing signals from disks having different sizes includes a spindle motor for rotationally driving a disk, a servo unit for controlling the rotation of the spindle motor, and a control unit for detecting an activation response state of the spindle motor upon starting, and switching a gain of the servo unit on the basis of the detection result.

Abstract: An optomagnetic disk recording and reproducing apparatus includes an optomagnetic disk having a vertical magnetic film capable of recording and reproducing an information signal, a recording and reproducing head unit for recording an information signal in the optomagnetic disk and reproducing an information signal recorded in the optomagnetic disk, a spindle motor for rotationally driving the optomagnetic disk, and means for controlling the spindle motor such that a rotational speed of the optomagnetic disk upon reproducing of an information signal recorded in the optomagnetic disk performed by the recording and reproducing head unit is set higher than the rotational speed of the optomagnetic disk upon recording of an information signal in the optomagnetic disk performed by the recording and reproducing head unit.

Abstract: A rotation control system for disk player in which the player detects the size of a disk housed in the player, varies the starting torque to be given to the disk motor in response to the detected size, and controls the disk motor so as to require substantially the same length of time before a prescribed rotational frequency is attained, irrespective of the size of the disk.

Abstract: Apparatus for detecting the speed of a moving object when exposed to primary magnetic flux fields and secondary external magnetic flux fields. The apparatus includes a magnetic device which generates the primary magnetic flux fields, a multi-coil device which carries induced electric currents when exposed to the primary magnetic flux field, and an error correction circuit for offsetting the effect of the magnetic flux from the external magnetic flux sources on the induced electric current. A support device is positioned between the multi-coil device and the magnetic device to allow relative movement therebetween, corresponding to the movement of the object.

Abstract: A high density spiral track forming apparatus according to the present invention includes a linear motion mechanism for moving an optical recording system in a radial direction of a disk-shaped substrate, and a length measurement machine for detecting the distance travelled by the optical recording system in the radial direction of the substrate disk. The apparatus further includes a velocity computing device for detecting the travel velocity of the optical recording system according to the detected result of the length measurement instrument, and a velocity control device which detects the difference between the travel velocity of the optical recording system which is detected by the velocity computing device and a predetermined velocity, and controls the linear motion mechanism so as to eliminate that difference.

Abstract: A front loading disk player of a type capable of playing disks of different diameters wherein the diameter and proper loading of the disk can be detected at all times with a simple sensor arrangement. The inventive disk player includes a housing, a playing mechanism provided in the housing and including an optical pickup and a turntable, the turntable including a tapered wheel received in the center hole of the disk, a disk conveying mechanism for conveying disks to the playing position, and a clamping mechanism for clamping disks conveyed to the playing position against the turntable. A detector detects the fact that the disk has been clamped against the turntable.

Abstract: In a disk size detecting circuit, the size of a disk is determined according to the speed of a motor adapted to rotate the disk and the angle through which motor has rotated after the start thereof. A counter, which is reset with the signal which starts the operation of the motor, counts pulses indicative of the amount of rotation of the motor. A rotational speed detector circuit, which may take the form of a frequency-to-voltage converter followed by a voltage comparator or a frequency counter followed by a digital comparator, produces a signal indicating the rotational speed of the motor. The output of the counter and the output of the rotational speed detector are applied to a circuit which discriminates the size of the disk according to the two signals.

Abstract: A rotation control apparatus for a motor comprises a motor for rotating or moving a recording medium, a circuit for generating first and second reference signals, a circuit for passing a signal which is obtained by comparing phases of the first reference signal and a synchronizing signal through a filter circuit thereof so as to produce a first error signal therefrom, a circuit for producing a second error signal which is obtained by comparing phases of the second reference signal and the rotation detection signal, and a control circuit for controlling first and second switching circuits. The control circuit supplies a specific signal having a level dependent on the level of the second error signal to a capacitor of the filter circuit through the second switching circuit and selectively passes the second error signal through the first switching circuit when the motor rotates at a rotational speed which is not near a steady state rotational speed.

Abstract: The rotation speed of a disc rotation motor is controlled such that a synchronizing signal derived from an output signal reproduced from a disc coincides with a reference oscillation frequency. The amount of data accumulated in a memory provided for absorbing jitter of the output signal reproduced from the disc is detected. In response to a result of the detection, a control signal in the disc rotation control is corrected such that the amount of data accumulated in the memory becomes substantially constant.

Abstract: A record disc playing apparatus comprises an address signal generating unit for generating address signals corresponding to horizontal rotational angular positions of a tone arm, a device for generating a rotational angular velocity signal corresponding to the rotational angular velocity of the tone arm, a circuit for controlling the rotation of a motor for driving a turntable, a control device supplied with the address signals and having a memory device from which is from which read out information corresponding to the addresses indicated by the address signals, and an attenuation circuit supplied with the rotational angular velocity signal and operating with an attenuation quantity, with respect to the rotational angular velocity signal, which quantity is varied by a signal from the control device. The rotational angular velocity signal corresponds to the quantity of any eccentricity of the record disc. The control device producing as output signals based on the information thus read out.

Abstract: There is disclosed a device for displacing a video disk with respect to a reading head which includes the driving of a conductive disk by means of a video disk rotational motor. The conductive disk passes through the air gaps of two electromagnets located on either side of the displacement axis of a movable member supporting the rotational motor. By differentially energizing the electromagnets, a force is produced which provides for forward and backward movement of the complete movable member of the reader.

Abstract: A video disc player is described for use with a video disc having frequency modulated video information recorded thereon in the form of a plurality of concentric circles or a single spiral. The information track comprises successively positioned light reflective and light non-reflective regions. A focused light beam is caused to be positioned over the center of an information track and the light reflected from the information track is gathered by an objective lens for application to electronic circuitry for recovering the recorded frequency modulated video signals. Radial tracking means are described for maintaining the focused light spot to impinge upon the center of an information track. Lens focusing means are described for positioning the objective lens at the optimum focused position above the information track for gathering the maximum amount of reflected light from the information track.

Abstract: A memory device utilizing metal oxide semiconductor field effect transistors (MOS FETs) formed in a semiconductor substrate. The memory device is so improved as to be accessed without a delay and as not to behave erroneously, in spite of a potential variation of data line or the semiconductor substrate. It comprises a plurality of row lines for supplying input signals, a plurality of column lines for supplying output signals, decoders for selecting any one of these lines, a plurality of memory cells connected to the row and column lines in a specific manner, a voltage sensing circuit connected to the column lines, a first potential source connected to the column lines, a second potential source for supplying the memory cells with a source voltage, and means for holding the column lines at a potential substantially equal to the voltage supplied from the second potential source when the potential of the column lines or the substrate varies.

Abstract: Three sets of light receivers are arranged on the turn table of a phonograph record player. The light radiated on the turn table is received and introduced to light receiving elements for conversion into a pulse signal. When a 30-cm record is placed on the turn table, the three sets of light receivers are all converted and fail to produce a pluse signal. When a 25-cm record is placed on the turn table, the first set of light receivers are exposed; while when a 17-cm record is placed on the turn table, the first and second sets of light receivers are exposed. The number of pulses produced from the light receiving elements is counted, thus determining the size of the record placed on the turn table.