Abstract: An access port for loading single tape cartridges into and retrieving single tape cartridges from an automated tape cartridge library system. A door is rotatably mounted in an opening in an exterior panel of the library system. The shape of the door is designed so that the opening is blocked at all times, regardless of the position of the door. A tape cartridge tray is mounted on the rear side of the door, slanted downward at a ten degree angle. The downward slant of the tray enables the robot to accurately find tape cartridges placed therein and restrains the tape cartridge from accidental dislodgement. A latch mechanism is provided to prevent the door from rotating when the robot is operating near the access port. The latch has an actuator preventing unlatching of the door. The actuator is activated by the operating system when it is safe to rotate the door. A tape cartridge is inserted into the tray and the actuator is activated to unlatch the door.

Abstract: A disk change signal generating circuit which uses an index sensor includes an index sensor for generating an index pulse in order to detect a rotation of a floppy disk, a timer for inputting the output of the index sensor into a clear terminal and inputting a clock signal into a clock terminal, thereby generating a counting value in a predetermined frequency, and a disk change signal generating circuit for generating a disk change signal by inputting the output of the timer.

Abstract: A magnetic recording/reproducing apparatus without a need to adjust what is known as X-distance of an Audio/Control head. In one embodiment, the apparatus comprises a reference pulse generator, a delay control pulses generator, and a first and second delay circuits. The apparatus compares the phase of a reproduced control pulse with that of a generated reference pulse and phase-shifts the reproduced control pulse in order to synchronize both pulses. By synchronizing the pulses, the apparatus compensates for the deviation of the X-distance. Another embodiment may be implemented using a microprocessor.

Abstract: A remote tracking control system for controlling the tracking operation by varying a reference signal of a reference phase counter by tracking up/down key signal of a remote transmitter. The system comprising a frequency demultiplier, a capstan counter, a NOR gate, a one-shot generator, microcomputer, a tracking monostable multivibrator, a reference phase counter, a comparator, a latch, a pulse width modulation signal generator, a pulse width modulation signal gate, a low pass filter, and an operational amplifier.

Abstract: A tape running time counting apparatus for video tape recorder includes a detecting device for detecting the existence or absence of playback control signals on a video tape, a pulse generating device for generating pulses proportionate to the rotational speed of one of a supply and a takeup reel and a counting device for counting real time of running of the video tape based on the playback control signals, when present, and for calculating the real time of running of the video tape after converting the number of pulses from pulse generating device in the absence of the playback control signals. If playback control signals are recorded the video tape, the tape running time is counted in real time based on the control signals. If the control signals are not recorded, the number of pulses which correspond to the rotational speed of the supply and/or take-up reel is converted into real time, thereby computing the tape running time. A method for count real time running of a tape is also disclosed.

Abstract: In a belt-driven tape cartridge of the type used to store data on a magnetic tape in a high speed data storage and retrieval system, the tape must be maintained at a proper tension within the cartridge so as to maintain the tape taut against the write/read head. Slackness in the tape occurs after a repeated number of changes in the tape transport direction or start/stop events, because the tension experienced by the tape is not the same in both transport directions. In a belt-driven cartridge, the tape tension cannot be directly monitored. A method and apparatus for maintaining tape tension in a belt-driven cartridge are disclosed wherein tape tension is indirectly monitored by non-mechanically monitoring a selected tape characteristic, the characteristic changing as the tape tension changes.

Abstract: Disclosed is a cassette loading system in a housing having an aperture which delivers a plurality of cassettes one cassette at a time into a cassette drive. The system includes a cassette drive having a cassette acceptor and a cassette magazine mounted through the aperture. The magazine defines a plurality of spaces, with each of the plurality of spaces sized and shaped to receive a cassette. The magazine is also adjustable within the aperture to align each of the plurality of spaces with the cassette acceptor of the drive. The system also include a cassette transfer system which moves each of the cassettes into the acceptor of the drive and retracts each of the cassettes upon ejection by the drive.

Abstract: A magazine for handling a plurality of tape cartridges. The magazine includes a plurality of vertically spaced, parallel shelves having tapered front edges with notches formed therein for ease of tape cartridge insertion. The slots slant downward to precisely position and restrain the tape cartridges magazine. A rib extends through each slot to engage in a tape cartridge notch. Improperly inserted tape cartridges will be forced to extend further out of the magazine so that they will be easily identified. A handle formed on the upper end of the front face of the magazine causes the lower end of the magazine to pivot forward to restrain the tape cartridges from accidental dislodgement. A locking strap is also provided to prevent the tape cartridges from accidentally dislodging from the magazine.

Abstract: A hard disk drive digital storage system provides increased power efficiency and reduced power losses by using a switching regulator type DC to DC power converter, to control spindle motor speed, in which a variable duty cycle, low "ON" resistance n-channel power MOSFET transistor is located near the ground side of the motor drive circuit. A voltage booster circuit provides higher gate control switching voltages to the motor power phase commutation switching transistors. A sense resistor is connected between the converter and ground, and the voltage developed across this sense resistor provides a signal which is coupled to the motor control circuit to vary the duty cycle of the converter to regulate the peak current applied to the motor.

Abstract: The invention is one or more tape systems which determine the length of tapes mounted therein to assess the thickness of such tapes. A format identifier is written at one of a plurality of locations on the tape depending upon the tape thickness. The format identifier for a relatively thin tape is written further from the leader block than that for a relatively thick tape, thereby avoiding the writing of user data in a region of the tape embossed with wrap deformations. The thickness determination is combined with a determination of the tape format to assess the compatibility of a desired operation on a tape mounted in a tape system therewith. If the operation is not compatible with the tape and the tape system, the tape system will not permit such operation to continue. A method for operating the tape systems is also disclosed, and accounts for various contingencies, such as blank tapes and marginal determinations of tape thickness.

Abstract: A driving apparatus for opening and closing a lid which is provided to open or close a recording medium insertion opening of a recording medium player. When the lid does not reach a fully opened position or a fully closed position in a predetermined period of time after the starting of opening or closing drive of the lid, such a fault condition can be removed by inverting the direction of rotation of a driving motor. Moreover, the lid is driven in the closing direction after a predetermined period of time from the time when a recording medium is inserted into the recording medium insertion opening, or the lid is driven in the closing direction in response to a closing command. By these operations, it is made possible to prevent the lid from being left in a halfway closed position.

Abstract: A tape conveying device has a loop bin which accomodates a meandering endless tape. The tape loop bin comprises a tape drive means, a tape running speed detecting means for detecting the running speed of the endless tape from the operating condition of said tape drive means, a tape conveying means for conveying the endless tape to meanderingly run in said loop bin to an exit from said loop bin, and a tape conveying control means complying with a running speed signal of the endless tape received from the tape running speed detecting means. Endless tape fed into the loop bin by a tape driving means travels toward an outlet from the loop bin. The tape conveying means is controlled to comply with a tape running speed signal sent from the tape running speed detecting means so that the operation of the tape conveying means is stopped before movement of the endless tape is stopped.

Abstract: A tray assembly (59) is provided with a lever (72) for unlocking the lid lock of a cassette (200). It is detected whether or not the lever (72) works to unlock the lid lock of the cassette (200), associating with the slot-in movement of the tray assembly (59), and the slot-in movement of the tray assembly (59) is prevented when the cassette lid unlock lever (72) is left inoperative.

Abstract: A recording or reproducing apparatus capable of replacing a recording medium is provided with a switch operable in connection with the loading or ejection of the recording medium, a circuit for intermittently detecting the state of the switch, a memory circuit for storing the output of the detecting circuit, a device for initializing the recording medium, and a control circuit for controlling the operation of the initializing device in accordance with the stored content of the memory circuit when electric power is supplied to the recording or reproducing apparatus.

Abstract: A computer storage unit usable with DAT cassettes. The unit has a tape drive, a carriage that is movable laterally relative to the tape drive opening, and a magazine having slots sized to releasably hold the cassettes therein. The magazine is releasable attachable to the carriage. A pair of gripper arms is rotatably mounted at the end of an arm attached to a traveler which moves the gripper arms between a selected magazine slot and the tape drive opening. The gripper arms are rotatable between a grasping position, a pushing position and an open position using a solenoid-driven actuator arm which linearly moves a head block to which the gripper arms are loosely connected at a position offset from their axis of rotation. A sensor is used in conjunction with the gripper arms to selectively move the cassettes during a test cycle to determine if cassettes are present in the magazine slots and whether the cassettes are in backwards.

Abstract: A control system for a magnetic tape cassette apparatus of the type requiring no movement of a transducer for the establishment of data transfer contact with the tape cassette. Inserted lengthwise in the apparatus, the tape cassette has its apertured front side oriented toward the fixed transducer. A cassette shift mechanism subsequently moves the tape cassette in its own plane into data transfer contact with the transducer. Then a pair of tape transport spindles are moved into driving engagement with the tape cassette by a tape transport shift mechanism. Both cassette shift mechanism and tape transport shift mechanism are actuated by a motor driven dual control cam under the control of a digital microprocessor controller.

Abstract: A recording and/or reproducing apparatus arranged to permit an interchange of record bearing media and selection between recording and reproducing modes of operation on the medium comprises look-up device for looking up the presence or absence of an existing record in each recording or reproducing position on the record bearing medium loaded on the apparatus, and control unit arranged to control the look-up device to cause it to perform a look-up action in response to opening of a lid for replacement of the record bearing medium and to cut off the power supply upon completion of the look-up action. The control unit thus lowers electric energy consumption and saves electric energy from being wasted by the look-up action.

Abstract: In a tape guide system having a tape guide device for guiding a magnetic tape in a video tape recorder or the like and which comprises a tape guide and an ultrasonic vibrator fixed to the tape guide for vibrating the tape guide with a standing wave, a drive device supplies a drive signal to the ultrasonic vibrator, and a temperature compensating circuit is provided for effecting temperature compensation of the drive signal supplied from the driver device to the ultrasonic vibrator.

Abstract: An automatic ejection system includes a loading device. The automatic ejection system has a grille detector for detecting the removing of a grille from a car stereo and for producing a detachment signal, a tape detector for detecting existence of a tape in the car stereo and for producing a tape signal, and ejection controller responsive to the detachment signal and the tape signal for operating the loading device so as to automatically eject the tape from the car stereo.

Abstract: A cassette tape-loading apparatus applied to a magnetic recording and reproducing apparatus using a cassette tape comprises a device for determining the amount of rotation of supply and take-up reels, a device for detecting the rotational direction of the reels, and a device for detecting the amount of tape drawn out of the cassette. Before loading the cassette tape, the ratio of winding diameter between the supply and take-up reels is computed, and the result is used to set the torque of the reel-driving motors and start the loading operation. At the time of loading, on the other hand, the amount of rotation of the two reels is determined, and the winding diameters of the reels computed from the winding diameter ratio and the amount of drawn-out tape thereby to set a proper tension of the magnetic tape.

Abstract: In a video tape recording and/or reproducing apparatus, a tape tension servo-system detects tape tension between a supply reel propelled by a voltage driven motor and the head drum to provide a corresponding detected tension signal supplied to a processor which is periodically interrupted for providing a control signal proportional to any deviation of the detected tape tension from a desired value and further for providing differential and integral control signals determined from the proportional control signal at successive interruptions and which are combined to form a control voltage signal for the supply reel motor. The processor is desirably constituted by a universal pulse processor and a central processing unit. The tape tension is detected by an angularly movable arm carrying a post about which the tape is wrapped sufficiently to ensure good compliance.

Abstract: A method for adjusting the tension of a tape in a tape drive is disclosed. The tape is loaded into the tape drive. A test signal is then provided to record test information onto the tape while the tape tension is varied concurrently in a prescribed manner. The test information is read immediately to provide a test readback signal. The test readback signal is processed to determine a functional relationship between the test readback signal and the tape tension. An operating tape tension value is computed based upon the functional relationship. The operating tape tension is implemented on the tape drive in the form of a command signal to a motor means of the tape drive.

Abstract: A portable audio apparatus allows a user to sing along with the recorded song, the user's voice and recorded song being outputted through a speaker. The apparatus permits the recorded lyrics or recorded tune of the song to be substantially eliminated prior to being reproduced by the speaker. The apparatus can operate in a fast forward or reverse mode and will stop between adjacent songs. A power savings circuit interrupts the supply of power to a motor to stop the latter from continuing to operate on a fast forward or reverse mode.

Abstract: There is disclosed a method of skipping unrecorded area during playback in order to minimize an interruption time upon playing back a recorded program in a tape drive. The method is performed while playing back a record medium, such that an area with no videos and audios is played back at a high speed and an area with videos and audios is played back at a normal speed, resulting in minimized time for playing back unrecorded areas, thus yielding another advantage in that an audience is kept from being bored and, furthermore, power is saved by automatically turning the power-off when the record medium playback is completed.

Abstract: A tape drive mechanism for a video tape recorder and an audio tape recorder. The tape drive mechanism automatically corrects the position of tape in the width-wise direction thereof without mechanically restricting the edge of tape. Sensors (8) and (8) on a tape path detect a dislocation of the tape (7) from a reference running position that may develop in the width-wise direction of the tape (7), a tape guide post (1) for attracting the tape (7) is moved in the width-wise direction of the tape, or inclination of a tape guide post (41) is changed to move the tape (7) in such width-wise direction by means of actuators (2), (42) and (62) that give corresponding displacement based on the values detected by the sensors (8) and (8), or the reel plate (57) is moved in the direction of width of tape to move the tape (7) together with the reel (24). The tape (7) having a small thickness is prevented against vertical movement on the tape path and is permitted to run stably without damaging the edges of the tape.

Abstract: An auto reverse type tape player is capable of selectively switching between a one-cycle mode and an endless mode. When a play button is operated once, the one-cycle mode is set and when the play button is reoperated within a prescribed period thereafter, the endless mode is set.

Abstract: An indicator provided on the surface of a video camera for warning of the occurrence of a matter which interrupts the recording; for example, dew on a recording head and the approach of a tape end. These occurrences during a recording operation must be informed to a subject as well as to a photographer who stands without looking into a finder of the video camera.

Abstract: An apparatus and method to automate the handling of multiple digital tape cassettes for processing by commercially available cassette tape readers and recorders. A removable magazine rack stores a plurality of tape cassettes, and cooperates with a shuttle device that automatically inserts and removes cassettes from the magazine to the reader and vice-versa. Photocells are used to identify and index to the desired tape cassette. The apparatus allows digital information stored on multiple cassettes to be processed without significant operator intervention.

Abstract: The present invention provides an automated cartridge loader 10 of novel design for use with a cartridge drive 12. In accordance with one aspect of the present invention, there is provided a sequentially loading cartridge loader 10 which allows the unattended storage of gigabytes of data. The loaders are adapted to be attached to a cartridge drive 12. The novel loaders of the present invention may comprise three moving components: the magazine 30, the pusher 91, and the gripper 93. Each moving component has its own drive motor 80, 94, 146. The magazine 30 has a plurality of slots 40 for holding cartridges 38 which are loaded into a cartridge drive 12. The pusher 91 of the present invention is aligned with the cartridge drive 12 and pushes the cartridges 38 into the cartridge drive 12. The gripper 93 closes on a cartridge 38 after it is ejected from the cartridge drive 12 and holds the cartridge 38 as the pusher 91 moves back to pull the cartridge 38 back into its slot 40 in the magazine 30.

Abstract: A hard disk drive digital storage system provides increased efficiency and reduced losses by using a switching regulator type power supply in which a variable duty cycle, low resistance n-channel field effect transistor is located near the ground side of the motor drive circuit. A voltage booster circuit provides higher switching voltages to the motor power phase control switching transistors.

Abstract: This invention relates to a high-speed magnetic tape transfer apparatus which has a reel motor for transferring tape wrapped around a cylinder having a rotary head at high speed and a capstan motor for transferring the tape at a standard speed. A detection section detects either a predetermined amount of the magnetic tape wound around a reel, a predetermined speed of the tape, or a predetermined current flowing in the reel motor, and generates a signal responsive thereto. A control section switches a device for transferring the magnetic tape from the reel motor to the capstan motor in response to the detection signal.

Abstract: Motor control apparatus comprised of a drive circuit for supplying drive current to a motor, an overload detector coupled to the motor for detecting the magnitude of the motor current to produce an output signal if that current exceeds a predetermined threshold level caused by motor overload, and a control circuit coupled to the drive circuit and responsive to the output signal for controlling the drive current supplied to the motor, thereby controlling motor operation.

Abstract: In a video tape recording and/or reproducing apparatus, a tape tension servo-system detects tape tension between a supply reel propelled by a voltage driven motor and the head drum to provide a corresponding detected tension signal supplied to a processor which is periodically interrupted for providing a control signal proportional to any deviation of the detected tape tension from a desired value and further for providing differential and integral control signals determined from the proportional control signal at successive interruptions and which are combined to form a control voltage signal for the supply reel motor. The processor is desirably constituted by a universal pulse processor and a central processing unit. The tape tension is detected by an angularly movable arm carrying a post about which the tape is wrapped sufficiently to ensure good compliance.

Abstract: A disc apparatus includes a drive mechanism rotatively driving a disc recording medium and having a motor and a chucking mechanism provided on a shaft of the motor, a head reading out information from the disc recording medium, a disc loading detector for outputting a loading detection signal when the disc recording medium has been loaded into the disc apparatus, a chucking control circuit outputting a motor rotation control signal for driving the motor during a chucking operation by the chucking mechanism, a motor drive control circuit driving the motor when at least one of a motor rotation control signal from the chucking control circuit and from an external information processing apparatus controlling the disc apparatus are supplied, an information output circuit supplying information obtained from the head to the external information processing apparatus during the motor is rotated on basis of the motor rotation signal, and an output prohibit circuit prohibiting the supply of information from the informat

Abstract: In a tape recorder, a tape tensioning device for tensioning the tape in a tape cassette comprises a movable member for causing a tension detection switch to open when the movable member is moved in a first direction, and a gear mechanism composed of first and second gears and a tensioning gear meshable with the first and second gears upon movement of the member in a second direction, to rotate one reel spindle. The tensioning gear is movable about the first gear upon inhibition of rotation of the spindle. The device further includes a brake for inhibiting rotation of the other spindle, and a retaining mechanism responsive to movement of the gear for further moving the member in the first direction to retain the member in such a position that the gear is moved away from the first and/or second gears, to release the other spindle from the brake mechanism and to return the member to the second direction upon unloading of a tape cassette.

Abstract: A tape cleaning apparatus for a tape recording and/or reproducing apparatus prevents possible dropping of recording or a possible dropout during recording and/or reproducing operation of a tape while the tape is fed at a low speed and can protect the tape when the tape is fed at a high speed to effect fast feeding or rewinding thereof. The tape cleaning apparatus comprises a blade made of an abrasion resistant material and located on the upstream side of a recording and/or reproducing section of the tape recording and/or reproducing apparatus in a direction in which the tape is fed at the low speed. The tape cleaning apparatus also includes a controller for controlling the blade to assume a first position at which the blade contacts with the tape to remove foreign substance sticking to the tape when the tape is fed at the low speed but to assume a second position at which the blade is spaced apart from the tape when the tape is driven at a high speed.

Abstract: A magnetic head device has a magnetic head slider by means of which information is recorded in and read from a magnetic recording medium. The magnetic head slider is supported by a supporting structure having an internal cavity, an opening formed in a portion of the structure where the magnetic head slider faces the magnetic recording medium and communicating with the internal cavity, and a gas passage through which the gas introduced into the internal cavity through the opening is discharged to the exterior of the internal cavity. With this arrangement, the pressure acting on the back surface of the magnetic head slider is adjusted to keep the slider afloat, while removing dust suspended in the gas around the recording medium and the supporting structure.

Abstract: A method and circuitry are described for sensing the clearance between a magnetic transducer and a moving magnetic recording medium in a magnetic disk or tape storage system or alternatively sensing the degree of magnetic instability of a magnetic transducer in such a system. Magnetic transitions prewritten on a preselected area of the medium are read to obtain a readback signal. The width of said signal is sensed at a predetermined amplitude level which is a preselected percentage of its base-to-peak amplitude to provide a voltage corresponding to the width of said signal at said level. The voltage is proportional to the width of the readback signal divided by the time period between successive transitions of identical polarity, so as to provide a measurement of clearance of degree of magnetic instability that is independent of the relative velocity between said transducer and medium.The voltage is digitized and compared to a prestored digital reference value.

Abstract: A tape transport apparatus is comprised of a friction type capstan servo block having a friction type capstan driven by a capstan motor controlled by a capastan servo circuit in response to a control signal for determining a velocity of the capstan and a pulse signal generated in response to a rotation of the capstan motor, a reel servo block having a supply reel and a take-up reel driven by a supply and take-up reel motor controlled by a supply reel and take-up reel control circuit respectively, first and second tape tension detectors for detecting tape tension of the tape locating between the capstan and supply reel and between the capstan and take-up reel respectively, a control voltage generator for generating a control voltage, a tape tension control data generating circuit having a memory, the memory having a plurality of back tension characteristics data each of which is changed in response to the pulse signal so that the back tension of the supply reel motor is controlled in response to an outlet sign

Abstract: An apparatus for recording information signals on a record carrier in the form of a tape can be set to an "information-signal-controlled recording" mode. The record carrier is driven by a motor drive arrangement (12) which includes two non-positively cooperating drive elements (15, 16) which are pressed constantly against one another during such recording mode, the motor being started by a motor control circuit (43) upon occurrence of an information signal which is detected by an information signal detector 40. The motor control circuit switches the motor off with a delay following termination of the information signal, and includes a pulse generation device (G) which, if during the recording mode the information signal fails to appear for longer than a time interval (T.sub.2) generates short control signal pulses (M.sub.1) which recur at such time intervals (T.sub.

Abstract: An apparatus for recording and/or providing with a lid for protecting the recording medium and a recording medium loading/ejecting mechanism that includes a housing, an inlet provided on a wall of the housing, a cassette which is loaded in and ejected from the housing through the inlet. The lid member is capable of being opened and closed and covers the inlet when it is closed. The apparatus includes a mechanism for loading the cassette inserted in the inlet to a loading position and ejecting the cassette from the loaded position to an ejection position. A detector detects whether the lid member is opened or closed. In addition, there is a controller for controlling the mechanism. The controller includes a loading controller for controlling the mechanism when the cassette is inserted in the inlet and is loaded in the loaded position.

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: A disc storage unit includes a processor for checking whether or not rotation of a disc occurs, head actuator for slightly displacing the head by a predetermined minute amount. At first, the disc is started and then the processor detects presence or absence of rotation of the disc, and the head is displaced slightly in a state in which driving force is applied to the disc by the head actuator.

Abstract: A rotary head type recording or reproducing apparatus of the type in which the recording or reproduction of signals is effected by tracing a recording medium transported in a predetermined direction with rotary heads in a direction which is at less than 90.degree. with respect to this predetermined direction. The apparatus is provided with a rewinding mode in which the above-mentioned recording medium is transported in a direction reverse to the above-mentioned predetermined direction without performing the recording or reproduction of signals, with the rotary heads being in the condition where they can trace the recording medium. In this rewinding mode, the rotary heads are rotated in a direction reverse to their rotating direction during the recording or reproduction of signals.

Abstract: A cassette loading apparatus for a video tape recorder includes a cabinet having a cassette insertion opening therein which is adapted to insertably receive a video tape cassette, and a lid mounted on the cabinet for movement between a first position, wherein the cassette insertion opening is closed, and a second position, wherein the cassette insertion opening is open. A cassette holder is adapted to accept and hold a cassette inserted therein and is movable between a cassette insertion position, which is adjacent to the cassette insertion opening, and a cassette operation position, spaced rearwardly and downwardly from the cassette insertion position. A cassette holder driving mechanism is provided to move the cassette holder between the cassette insertion position and the cassette operation position.

Abstract: The information signals recorded on a magnetic tape are accompanied by marks identifying particular items of such information, each mark (M.sub.1) comprising at least one marking signal (S.sub.1), the tape being driven by a tape-up reel hub (5) during recording. During playback a magnetic head (19) reproduces the recorded signals and a tachometer (46) coupled to the take-up reel hub (5) supplies a tacho-signal which is used by a microprocessor (42) as a reference for frequency comparison with the instantaneous frequency of the reproduced signals. When a predetermined relational condition exists between such frequencies the microprocessor (42) produces a signal indicating the presence of a mark (M.sub.1). Since the frequency of the tacho-signal and the frequency of the reproduced signals from the tape are affected in the same way by variations in speed of the take-up reel hub, such variations do not affect accurate detection of the recording marks.

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: Motor control apparatus comprised of a drive circuit for supplying drive current to a motor, an overload detector coupled to the motor for detecting the magnitude of the motor current to produce an output signal if that current exceeds a predetermined threshold level caused by motor overload, and a control circuit coupled to the drive circuit and responsive to the output signal for controlling the drive current supplied to the motor, thereby controlling motor operation.

Abstract: A video cassette rotary scanner is adapted for high capacity, high speed, digital audio spectrum data recording by the use of a buffer memory and a servo control system. The buffer memory is operative at a speed much higher than that of the tape. The tape is maintained at relaxed tension until a high data occupancy signal from the buffer activates the data write operation. In response, the tape tension is increased for a write operation, and relaxed again only when the buffer sends a low data occupancy signal. The use of the buffer along with capstan, take-up reel and supply reel motors responsive to the two signals permits tape wear to be decreased substantially while increasing tape capacity.

Abstract: An improved switching regulator .Iadd.DC-DC power converter or .Iaddend.power supply with a variable duty cycle is disclosed which forms part of a compact Winchester disk drive system having a storage capacity in excess of 380M bytes of information. The switching regulator is designed for frequencies in excess of 80 kilocycles per second and may therefore be construced using smaller capacitive and inductive elements. Also, very low heat dissipation and high regulator efficiency may be achieved by the improved .Iadd.power converter or .Iaddend.power supply to drive a brushless D.C. motor encased within a hard disk assembly where no separate fan or cooling system is used to aid in heat removal. Circuitry is provided to control the motor speed while simultaneously limiting the motor current to a predetermined level. This is a achieved by controlling the voltage applied to the motor by suitably adjusting the duty cycle of the switching regulator.