Abstract: When a photoelectric detector in a record player is moved under the control of a signal supplied by a control circuitry in order to detect a required unmodulated space on a surface of a record disk to be played, a pickup arm is moved according to an output of a servo-amplifier so as to assume a position with respect to the record disk corresponding to a position assumed by the photoelectric detector. The servo-amplifier is inputted with two voltages related to the positions of the pickup arm and the photoelectric detector both relative to the record disk. After a required unmodulated space is detected, the pickup arm is switched over to be controlled of its movement in accordance with a signal delivered from the control circuitry, and will trace the record groove of the disk, while the movement of the photoelectric detector is controlled by an output of the servo-amplifier.

Abstract: In the construction of a photoelectric type rotation angle detector for a rotatable or turnable object including a photoelectric transducer, an optical interceptor and a comparator circuit, a cylindrical light interceptive portion extends parallel to the main shaft axis of the interceptor, the optical trace of the transducer extends across the light interceptive portion, and angular deviation of the object from a standard angular position induces corresponding relative rotation between the transducer and the interceptor for generation of a corresponding output from the comparator circuit.

Abstract: A rudder control circuit for an automatic steering system of the type which includes a known sensor circuit and a reference input circuit selectively connected thereto for easy zero-point calibration separate from the normal control operation is disclosed. The control circuit also includes a high impedance indicator circuit connected to the main feedback line of the control circuit for visual indication of rudder angles with minimized disturbance on the feedback control. The control circuit is further advantageously accompanied by a remote steering unit including a manually adjustable and automatically resettable manual steering circuit for easy steering by single operator.

Abstract: As a substitute for the conventionally used pair of polarizer panels, a sensor disc is used in relatively rotatable combination with a pair of photo-sensitive elements arranged spatially on one side of the sensor disc and a light source system arranged spacially on the other side of the sensor disc. The optical transmittancy of the sensor disc changing either continuously and/or discontinuously in a selected diametral direction. The difference in the incident optical quantity caused by relative rotation of the disc and the elements causes generation of corresponding output from a detecting mechanism electrically coupled to the elements. The wide range of the detectable rotation angle enables advantageous use of the sensor for a navigation course finder, linear tracking arm system for record players, automatic steering system and weighing balance.

Abstract: In an automatic record disk player, various information as the disk size, the position of the pickup arm, and various operation commands, is supplied as digital signals to a logic circuit, in which logical operations are carried out to control the pickup arm according to a select operation sequence. Manual operation is compatible with the automatic operation, and interruption or discontinuation of play can be achieved at any moment.

Abstract: A control device for controlling the movement of the pickup arm of a record player or the like. This device comprises: a movable member; a motor for driving this movable member; a relative position detecting means for optically detecting the horizontal relative positions of the pickup arm and the movable member and for conrolling, by the output signal of the detecting means, the direction as well as the speed of rotation of the motor to thereby cause the movable member to move while keeping a certain distance from the pickup arm; and a lifter means provided on the movable member and adapted to be actuated at a desired position of the pickup arm for lifting up this pickup arm and holding same at its uplifted positions. This control device will not be brought into mechanical connection with the pickup arm during the period other than the period during which time the device is controlling the movement of the pickup arm.

Abstract: An electronic musical instrument of the waveshape memory type comprises a holographic memory; including a plurality of hologram pictures each carrying information of dots which represent in binary coded notation sample values constituting musical waveshapes. Upon key depression, a coherent light beam irradiates the hologram pictures corresponding to the depressed key to reproduce dot images on a photo-electric converter. The converter delivers digital values of waveshape samples. The digital values are converted to analog values, thereby producing musical tones. A large amount of information can be stored in a small size memory.

Abstract: A disc player in which a servo-driven carriage supporting a pickup arm assembly via a block mounted thereon is movable along a linear path substantially normal to an imaginary radial line of a disc turntable, the level of the block being adjustable as required relative to the carriage. A gimbal support mechanism, a pickup arm lifting mechanism, a pickup arm offset angle detecting mechanism and a pickup arm positioning mechanism are all encased within the block, thereby assuring a compact construction, successful slashing of noisy vibrations of mechanical parts conventionally causing lowering of reproduction quality and simple adjustment after replacement of mechanical parts.

Abstract: An electromagnet type pickup device including a vibrating tubular member supporting a stylus-carrying cantilever and having a funnel-shaped engaging portion formed at one end, and including a tension wire having a bulging portion formed at one end, the other end being passed through the tubular member and secured thereto under tension so that the bulging portion is secured in said funnel-shaped engaging portion, thereby enhancing the firm engagement between the vibrating member and the supporting wire to establish the non-swaying center of vibration of the vibrating member.

Abstract: A pickup arm device having a dynamic damper and an adjustable dynamic lateral balancer both of which are provided between the head shell and the fulcrum at which the pickup arm is supported. The dynamic lateral balancer is arranged so that it has a low center of gravity. Accordingly, the lateral balance of the pickup arm does not vary throughout the tracking movement of the pickup arm. Also, the position of the weight pieces of the balancer can be adjusted to obtain the desired reproduction frequency. Furthermore, by the adjustment of compliance and resistance of the damper, it is possible to vary only the resonance peak of the resonance frequency in the low frequency range of the pickup arm device.

Abstract: In a linear tracking pickup apparatus of a record player, a video disc player and the like wherein a pickup arm is swingably and pivotally supported on a gimbal support mechanism, a device for detecting an offset angle of the pickup arm comprising: a light-reflecting surface formed on a portion of a first frame as a part of the surface of this portion, which first frame being a portion of the gimbal support mechanism and swingable with the horizontal swing of the pickup arm; a light-emitting source fixed to a second frame, not swingable but only linearly movable, of the gimbal support mechanism so as to face the light-reflecting surface; and a photo-sensitive element fixed to the second frame for receiving the light rays reflected by the light-reflecting surface.

Abstract: On a phonographic disc player, a carriage for supporting a phonographic tone arm is movable along a pair of mutually parallel front and back guide rails and an elongated cover arranged between the guide rails while the position thereof normal to the moving direction being constrained in a precise manner through rolling meshing engagement of at least one of its bottom inside wheels with an associated guide rail, a bottom block extending downwardly from the carriage through the back rim horizontal slit in the cover back being operatively coupled to a servo-driving mechanism which is electrically connected to a given tone arm offset angle detecting circuit.

Abstract: A pickup arm driving device in a linear tracking apparatus. The offset angle of the pickup arm is photoelectrically detected to produce a corresponding offset angle signal for driving a motor to move the pickup arm. Completion of the reproduction of sound from a disc causes a groove end detection signal which operates an electromagnetic lifter causing upward swinging of the pickup arm and a quick return of the pickup arm to an arm rest position.

Abstract: A mechanism for supporting a pickup arm in a linear tracking arm type disc record player comprising an upper guide rail having a groove, a lower guide rail extending parallel to the upper guide rail, and a pickup-arm supporting movable frame having first rollers engaging in the groove of the upper guide rail for suspension of the movable frame therefrom and having second rollers contacting the lower guide rail to allow the movable supporting frame to make smooth linear travel on this lower guide rail without unwanted pivotal movement. This arrangement insures smooth linear tracking of the pickup arm with no rattling-type travel and eliminates the need for highly trained skill in assembling the whole mechanism.

Abstract: An electromagnetic solenoid with a yoke defining a hollow cylinder, an electromagnetic coil wound around this cylinder for connection to a power source, a plunger inserted in the cylinder for sliding movement therein when the coil is energized and having a needle-like rod extending through the yoke bottom, the plunger and cylinder each having a confronting surface which is faced with a confronting surface of the other during the sliding movement. A plurality of spaces are formed on the confronting surface of at least either the cylinder or the plunger, and a braking substance consisting of a highly viscous liquid is applied to the confronting surfaces of the plunger and cylinder. Spring means may be operatively provided about the plunger to return the slidingly moved plunger to its original position. Upon energization of the solenoid, the downward movement speed of the plunger is limited by the braking substance.