Abstract: In an antiskid control device comprising detectors for measuring circumferential velocities of a plurality of wheels an actuator for operating a braking oil pressure for each of the wheels and an electric circuit for calculating friction coefficients on the road surfaces, to which the wheels are in contact, calculating aimed wheel circumferential velocities from the friction coefficients on the road surfaces and operating the actuator such that each of the aimed wheel circumferential velocities and each of the measured wheel circumferential velocities coincide with each other, the electrical circuit operates the actuator by setting individual aimed wheel circumferential velocities for the plurality of wheels from a vehicle deceleration calculated from an average value for the friction coefficients on the road surfaces with which a plurality of wheels are in contact, respectively, and the slip ratio for each of the plurality of wheels.

Abstract: An antiskid control device, comprising a detector for detecting a circumferential speed of wheel, a valve for controlling a hydraulic braking force to the wheel, and an electronic control circuit for determining a ratio of a mean value of rising rates and a mean value of lowering rates of the circumferential speed of wheel in a predetermined period of time in every antiskid control cycle for rise and drop of the circumferential speed of wheel based on a detection signal from the detector, for estimating a coefficient of friction of road surface from the ratio to correct the target circumferential speed of wheel based on the estimated coefficient of friction of road surface, and for operating the valve means to let the wheel circumferential speed approach the corrected target circumferential speed.

Abstract: An anti-skid control device comprising a detector for detecting a wheel circumferential velocity, an electromagnetic valve for controlling a hydraulic braking pressure for a wheel and an electronic control circuit for preparing an aimed wheel circumferential velocity based on a detection signal from the detector during a time of braking and controlling the electromagnetic valve so as to bring the wheel circumferential velocity closer to said aimed wheel circumferential velocity.

Abstract: The combination of a cylindrical casing, a rod member axially reciprocable in the casing, a rotary member fitted in the casing and rotatable therein in relation with axial displacement of the rod member, an inertia member rotatably fitted in the casing opposingly to the rotary member, and a rotation control member interposed between the rotary and inertia members and adapted to rotate the inertia member with the rotary member in rotation at a low speed and to move the inertia member axially away from the rotary member in rotation at a high speed to abut the inertia member against a wall portion of the casing to restrict the rotation of the rotary member. An intermediate brake is provided between the rotary and inertia members to apply a force resistive to relative rotational displacement of the rotary and inertia members.

Abstract: A flexible arm for a program controlled manipulator, with a hydraulic rotary actuator supported on an inflexible arm, a first arm member secured to a rotary shaft of the actuator, a second arm member connected swingably to the first arm member by way of a shaft, a third arm member connected rotatably to the second arm member, a link member connected rotatably to the first and third arm member, and a working tool mounted to the free end of the flexible arm.

Abstract: Information play-back apparatus comprising a laser source, a recording medium, a photodetector, a first optical system which conducts a laser beam from the laser source to an information track on the recording medium as a read spot, and a second optical system which conducts a reflected laser beam from the information track to the photodetector through an optical element having the unidirectional lens action, said optical element being arranged in a manner to define an angle of about 45 degrees relative to the direction of the information track, and said photodetector having at least four light receiving portions divided symmetrically about two axes such that at least one light receiving portion is in each of the four quadrants formed by two axes, and one of the axes is parallel to the direction of the information track.

Abstract: In automatic focusing apparatus comprising a laser source, optical means for causing a light beam from the laser source to follow an information track on an information recorded medium, a photodetector which consists of quartered photodetection portions and to which a reflected light beam from the information track is guided through a cylindrical lens, and means for controlling the focusing of the light beam by the use of an error signal obtained from the shape and the intensity distribution of a light spot on the four photodetection portions, the improvement wherein a compensation signal is created from the absolute value of a difference between outputs from one set of the opposing photodetection portions and the absolute value of a difference between outputs from the other set of the opposing photodetection portions, to compensate for a disturbance ascribable to a movement of the light spot on the photodetector which arises in correspondence with the error signal.

Abstract: Information play-back apparatus comprising a laser source, an information recorded medium, optical means for guiding a laser beam from the laser source to an information recorded track on the information recorded medium, and means for varying the size of the spot of the laser beam on the information recorded track in dependence on the position of the track on the information recorded medium.