Abstract: A method and apparatus for driving a two-phase motor having two phase coils and a head of a disc recording unit which records information data and servo information on a rotatively driven disc in a manner designed to assure proper placement of the servo tracks and increase the speed of reading and writing information data. The head is driven to first radial locations on the disc by exciting phase coils in an unbalanced condition with two phase currents which have differing non-zero magnitudes, and servo information is written at these locations as the disc rotates.

Abstract: A DC motor drives a magnetic disk memory transducer head between a position proximate the disk periphery to an area on the disk where data are located during which time the head is lowered from an idle to a hovering position. During this time the motor is supplied with a current impulse having a predetermined polarity, amplitude and duration. The polarity of the current impulse is opposite to that of current applied to the motor while the head is being driven between a position beyond the disk periphery to the position proximate the disk periphery. The duration and amplitude of the current impulse are such that the motor angular velocity has a zero value at the completion of the current pulse. Thereafter, a ramping voltage having an average linear waveform is applied to the motor to prevent overshoot of the motor speed and prevent oscillation of the head relative to a face of the disk. The linear ramp current decreases to a zero value, at which time the motor has a constant, non-zero angular velocity.

Abstract: In a floppy disk drive, the head position is controlled in accordance with prerecorded sets of sinusoidal bursts recorded first on the right side of each track and then on the left side of each track in the narrow separation space between each pair of adjacent disk sectors. The serial bursts are peak detected and then integrated by the same peak detector and the same integrator, the integrals of the right and left bursts being substracted and transmitted to the head tracking servo as a position error signal. The process of peak detecting prior to integration removes the detected wave shape (which changes with track radius) as a factor in the position error computation, thus eliminating dependency of the error computation on the track radius. Using a single channel--the same peak detector and the same integrator--to process both the right and left hand sinusoid bursts eliminates offset errors in the tracking error computation characteristic of dual channel devices.

Abstract: An optical information recording and/or reproducing apparatus is provided with a finely moving device. The movement of an optical device converging and radiating a light beam onto an optical information recording medium, is controlled to be able to finely move the position of a spot light radiated onto the recording medium. A coarsely moving device moves an optical head provided with the finely moving device and an optical system. A track crossing velocity monitoring device detects whether the track crossing velocity at which the spot light radiated onto the recording medium crosses the tracks of the recording medium is below a predetermined value. After a coarse access close to an objective track is made by the coarsely moving device, when the track crossing velocity is below the predetermined value, the clamping applied to the optical device at the time of the coarse access will be released.

Abstract: An optical disc apparatus arranged so that a light beam from a laser light source is focused by an object lens and irradiated on an optical recording medium having thereon a mirror surface and tracks of a plurality of pits for recording data, and that a reflected beam from the recording medium is irradiated on an optical detector from which a signal on the recording medium is reproduced for maintaining a position of said object lens at an optical center axis by a tracking servo. The optical detector includes at least two adjacent photoelectric transducers providing outputs indicative of the reflected beam incident thereon, a device for producing a signal indicative of a difference between the outputs from the transducers, and a position detector for detecting the position of the object lens in a direction perpendicular to the tracks in cooperation with said difference producing device.

Abstract: Method and apparatus for processing information on a recording member having a recording film capable of recording and erasing information in accordance with the change of a magnetizing direction, by utilizing a light induced thermo-magnetic effect, in which before the intensity of the laser light is switched at the high level eliminating the magnetization of the recording film in order to effect the recording and erasing operations by focusing the laser light on the recording film as a light spot, a magnetic field with the predetermined direction according to the recording and erasing operations is previously applied on the recording film, whereby the recording and erasing operations of the magnetized information can be effected with high speed and stably by applying the normal magnetic field in the direction according to the recording and erasing operations respectively.

Abstract: A point of purchase advertising system is provided which senses the presence of a person in the vicinity of an advertising display and thereupon renders an appropriate advertisement such as a recorded verbal message or a visual or aural demonstration. In preferred forms, the overall apparatus includes an ultrasonic sensing circuit for detecting the approach of a potential customer, an advertisement giving device, typically an endless tape playback unit and a coupled speaker, and a controller for operation of the playback unit in response to detection of a customer. A voice operated relay circuit is advantageously coupled with the audio output of the playback unit and the playback controller, so that operation of the playback unit is maintained until the entire recorded advertisement has been given.

Abstract: An apparatus for driving a floppy disc includes a first sensor responsive to a magnetic disc encased in a jacket of the floppy disc. Before the magnetic disc is gripper in a predetermined position, a d.c. motor included in a disc rotating mechanism is started in order to prevent rush current therethrough. After the start of the d.c. motor, a second sensor senses a return of the magnetic disc to a predetermined regular position whereupon a cone load drive source is activated to automatically move a cone toward a drive hub. Thus, the magnetic disc can be gripped and set in the regular position merely by inserting it into the apparatus. The apparatus also includes ejection apparatus for ejecting the floppy disc.

Abstract: A tracking servo circuit for controlling an optical pickup is used in a tracking error detecting device including an optical system for forming on an optical disc a main light spot for illuminating a pit on the optical disc and forward and backward sub-light spots. The forward and backward sub-light spots are disposed before and behind the main light spot in the moving direction of a track with a small distance between each of the sub-light spots and the main light spot and are shifted from the center line of the track, so that a half of each sub-light spot area is placed on the pits of the track.

Abstract: Method of and apparatus for making a test strip and a test strip made by such method having a longitudinally extending carrier and a test field thereon. The carrier has a layer of magnetizable material thereon in which an amount of data for the storage of information has been applied in the longitudinal direction of the magnetizable material. The carrier has a recess near each end thereof adapted to provide a required alignment and positioning of the strip.

Abstract: A control signal generating circuit for a magnetic recording and/or reproducing apparatus comprises a monostable multivibrator for producing a pulse signal having a predetermined pulse width in response to a reference signal from a supplying circuit of the recording and/or reproducing apparatus, a flip-flop circuit responsive to the output pulse signal of the monostable multivibrator, for inverting an output thereof every time the pulse signal is supplied thereto, and an OR gate for producing a control signal responsive to the output pulse signal of the monostable multivibrator and the output of the flip-flop circuit, and for supplying the control signal to a control head, of the recording and/or reproducing apparatus, which records and/or reproduces the control signal on and/or from a magnetic tape.

Abstract: A real-time magnetic digital video disk recording system has been developed for applications in on-line digital imaging systems and off-line fast access image storage and retrieval buffers. The disk recorder uses new high density recording technology and Winchester computer drive technology in a unique peripheral configuration which is fully synchronized to video system timing, provides for flexible formatting, achieves fast random access to a large video image file, and eliminates the need for complex data controllers. The recorder includes two independent actuator and head assemblies for alternately recording successive video fields on separate tracks on separate zones A and B of a disk stack. Movement of one of the actuators and head assemblies is controlled and occurs within a field time to skip tracks containing media flaws to achieve real time digital video recording.

Abstract: An electrical measuring system for measuring selected parameters of electrical signals derived from magnetic recording and having a frequency within a known frequency range wherein the system includes an input stage having an automatic amplifier for selectively amplifying the electrical signals to a preselected amplitude level, a first circuit which includes a digital peak detecting circuit for producing digital signals representing peak amplitude and the amplitude of the electrical signals sampled at closely spaced intervals and wherein the digital peak detecting circuit includes circuitry for sampling the preselected amplitude level electrical signals at a frequency which is less than the frequency of the electrical signals, a second circuit which includes a first phase-locked loop circuit, a frequency dividing circuit and a second phase-locked loop circuit for producing an output signal representing the frequency of a remnant signal in the electrical signals which is applied to the digital peak detecting c

Abstract: In the disclosed recording apparatus an arrangement moves a recording head relative to a record bearing medium, a detector detects when the recording head is in a substantially stabilized position, and a facility responds to the output of the detector to produce an output signal that enables the recording. This assures initiation of a recording operation when the head is in a stable condition.

Abstract: An optical end-of-tape detection device comprises a photodiode and a phototransistor. In order to distinguish the light emitted by the photodiode from the ambient light, the photodiode is operated in a pulsating fashion. Moreover, the low-frequency component of the photo current supplied by the photo-transistor is suppressed by negative current feedback.

Abstract: An overlay recording prevention device for an optical disc apparatus detects a signal corresponding to a recording pit of a recorded track. This signal is detected from a photoelectric signal of an optical head when a tracking error occurs in the recording mode and a beam spot is shifted onto an already-recorded track. A high-level recording laser beam is stopped in response to this detection signal.

Abstract: Recording tape cassette has pivotable spring means including a record-lockout tab which blocks an opening when the spring means is cocked. When placed on a cassette deck, a fixed tang on the deck releases the cocking, allowing the spring means and its record-lockout tab to pivot to a retracted position, thus unblocking the opening. Thereafter, a feeler on the deck can enter that opening to disable the record function.

Abstract: An information recording and reproducing apparatus wherein a light beam is applied onto an optical disk having pits previously formed in optical manner thereon. A tracking signal is detected from the light beam which has been modulated by the pits, and information is recorded by applying a record beam modulated by an information signal onto an area between one pit and the succeeding pit while tracking is effected by using the tracking signal.

Abstract: One broad wall of a recording cassette has a recognition hole which is covered by a breakout tab (here called a "removable piece"), and there is a chamber projecting from the other broad wall of the cassette such that a punch which dislodges the removable piece permanently wedges it into the chamber.

Abstract: A data track searching device capable of switching between two modes; one being the rough searching mode in which a transducer is displaced at a high velocity to a desired track and the other being the fine searching mode which follows the rough searching mode and in which the transducer is displaced at a relative low velocity and positioned over the proper or desired track. The operating point of a tracking element is shifted or deviated as a result of the high-velocity displacement of the transducer in the rough searching mode so that stable searching cannot be ensured. According to the present invention, therefore, the acceleration of the transducer in the rough searching mode is detected and a signal representative of the thus detected acceleration is applied to the tracking element so that the shift or deviation of the operating point of the tracking element can substantially made nil.