Abstract: A driving apparatus for driving an object comprises a pair of piezoelectric elements, one of them being arranged on the one side of the object while the other of them on the other side of the object, and the respective electrode arrangement directions of the pair of piezoelectric elements being substantially identical to each other, and a control circuit which applies a predetermined voltage across the outer electrodes of the pair of piezoelectric elements respectively, gives an equipotential to the inner electrodes thereof, and causes the pair of piezoelectric elements to drive the object by varying the value of the potential given to the inner electrodes. Hence, the increased amount of a voltage applied to one piezoelectric element is exactly identical to the decreased amount for the other so as to make the extended and contracted amounts of the piezoelectric elements on both sides of the object the same.

Abstract: An automatic disk changer in which a tray guide for storing a disk while it is not being played is provided in a case. A tray for containing the disk is guided by the tray guide. The tray has nearly the same size as the disk to be contained in the tray, and has a window through which a laser beam from a pickup passes and which extends to the peripheral portion of the tray. The disk changer includes a disk player which is also provided with a further tray guide for guiding the tray and is installed so that the disk is pinched and moved up by a turntable unit and a clamper and the tray is thereafter moved in the direction of movement of the pickup.

Abstract: A medium for irreversible information storage by locally changing the electrical conductivity of a carrier whose discrete areas of electrical conductivity have been produced by means of polymeric systems which contain conjugated double bonds and are formed by a field-chemical reaction, and a method for carrying out this information storage.

Abstract: The stylus arm restraint comprises an element disposed substantially perpendicular to the stylus arm, and having a portion that is received in a recess provided in the cartridge housing when the stylus arm is held inside the cartridge. The reception of the stylus arm-mounted element in the cartridge recess limits motion of the stylus arm during transit.

Abstract: A reproducing stylus traces a track of a recording medium, in which track an information signal is recorded as variations of geometrical shape, and reproduces as variations in capacitance the information signal thus recorded. The reproducing stylus comprises a reproducing stylus main structure having a tip part with a flat sliding contact face for slidingly contacting at least one track of the recording medium at a time, and an electrode secured to the reproducing stylus main structure at the tip part thereof and adapted to trace one track and reproduce the information signal as the variations in capacitance in accordance with the variations in geometrical shape. The electrode has over a specific distance over the tip part of the stylus main structure from the extreme tip thereof, a width in the width direction of the track which is less than said width of the track. The extreme tip of the electrode having a flat or linear tip end contacting the track.

Abstract: An electrostatic voltage detecting device includes a detecting electrode for detecting an electrostatic voltage generated by charge on a recording medium, a variable capacitance diode whose capacitance changes according to an output signal applied from the detecting electrode, a primary coil combined with the variable capacitance diode to form a resonance circuit, an oscillator for supplying an oscillating output signal of predetermined frequency to the primary coil, and a secondary coil inductively coupled with the primary coil. The capacitance of the variable capacitance diode changes according to an output voltage applied from the detecting electrode to vary a resonance frequency of the resonance circuit and consequently a voltage induced in the secondary coil.

Abstract: A playback stylus for a capacitive information disc comprising a shank, a dielectric material at one end of the shank, a first conical region of a first angle in an end portion of the dielectric material, a second conical region adjacent to the first conical region of a second angle less than the first angle, and an information recovering terminal region in the first conical region for recovering information recorded in an information track of a capacitive information disc.

Abstract: A playback stylus comprising a dielectric support element having a conical end, two flats in the conical end, and a constricted terminal portion defined by side surfaces, shoulders interconnecting the side surfaces and the flats, a prow defined by a first region between the flats, a second region remote from the prow and a disc engaging surface defined by the prow, side surfaces, and the second region.

Abstract: A capacitive information disc playback stylus comprising a dielectric support element having in one portion a conical body terminating in a constricted tip. The tip comprises a curved prow surface, a flat electrode surface remote from the prow, shoulders joining the constricted tip to the conical body, and side surfaces which join the prow and the flat surface. The side surfaces, the flat surface, and the prow surface define the edges of a disc-engaging surface.

Abstract: A pick-up assembly for use in a video disc player comprises a stylus having one lengthwise surface provided with an electrode and secured to a stylus carrier with the electrode facing in a direction away from the carrier, and a generally strip-shaped fly lead having one end bent and connected physically and electrically to the electrode by the use of an electroconductive bonding agent, thereby minimizing the required length of the expensive stylus and rendering to decrease the noise of the pick-up assembly.

Abstract: A signal pickup device in a rotary recording medium reproducing apparatus, comprises a cantilever provided with a reproducing element for picking up and reproducing a signal from a rotary recording medium at the tip end thereof, a support member having a support part for supporting the rear end part of the cantilever, and arms which unitarily extend on both sides from the support part, and a frame having engaging parts engaged with and mounted with the arms of the support member, for holding the arms. The arms of the support member respectively are provided with mounting parts having non-circular cross-section in the vicinity of the end part thereof, for engaging with the engaging parts of the frame. Moreover, the mounting parts and the engaging parts are shaped so that the support member is at an angular position together with the cantilever where the reproducing element is at a raised position, when the mounting parts are mounted onto the engaging parts.

Abstract: A cylindrical diamond body is shaped to form a truncated conical portion. A conductive layer is deposited on the diamond body extending from the truncated end to the other end of the body. The conical portion of the body with the conductive layer being attached thereto is lapped to remove portions of the layer and the diamond body to form a pair of substantially flat surfaces extending from the truncated end toward the opposite end leaving the conductive layer to form a narrow width electrode for picking just one information signal stored in the form of minute pits along a spiral track or concentric tracks.

Abstract: An improved information storage and recovery system comprising a playback stylus, having a dielectric support element and a conductive electrode, and a grooved conductive disc record in which information is recorded. The information is recovered on playback while there is relative motion between the record surface and the stylus by sensing capacitive variations between the stylus conductive electrode and the record surface. The improvement comprises employing that angle between the electrode face and the record surface such that the respective paths of dielectric effects between the electrode face and the record surface both in the direction of relative motion and in the direction opposite the direction of relative motion are balanced.

Abstract: A signal pickup device comprises a reproducing element for reproducing recorded signals from recording tracks of a rotary recording medium, a holder having said reproducing element mounted at its tip end, a cantilever having the rear end of said holder mounted at its tip end, force applying coil for applying a force to the rear end side of the cantilever so that the reproducing element makes contact with the rotary recording medium having a predetermined pressure, and control coils for applying force at the rear end side of the cantilever so that tracking control is performed, by displacing said reproducing element in a direction perpendicular with respect to the longitudinal direction of the recording tracks of the rotary recording medium.

Abstract: The invention describes a method and apparatus for reconditioning a video disc signal pickup stylus electrode to prevent electrode-disc electrical shorts. An AC or DC potential is repetitively applied during a predetermined period between the stylus electrode and the disc to produce electrical breakdown at the electrode-disc interface and vaporize a portion of the electrode material. In the capacitive type video disc system, the capacitance sensing pickup circuitry is repetitively tuned to couple excessive amounts of rf potential to the stylus electrode.

Abstract: An improved method of reproducing a spiral groove pattern in the surface of a plastic disc wherein the intersections of the surface of a metal article generated during the replication process are filled in to form concave junctions.

Abstract: A system for measuring shoe length of a stylus adapted to track a path along a surface of a video disc comprises positioning the tip of the stylus adjacent the surface of a substrate having a signal therein for effecting capacitive variations between the stylus and the substrate, and measuring the capacitive variations between the stylus and the substrate while they are oriented in a first position to obtain a first signal. The stylus is then tilted an angle of .theta. degrees relative to the substrate, whereby the stylus and substrate are oriented in a second position relative to each other. The capacitive variations are measured while the stylus and substrate are oriented in the second position to obtain a second signal. The first signal is then compared with the second signal to obtain a difference signal proportional to the shoe length of the stylus.