Abstract: A rotation detecting device for vehicle speedometers includes a housing, a magnetic induction device, and a magnetized rotor near the magnetic induction device. The rotor is connected through a coupling to a rotation source. A braking device forms a magnetic circuit between one end surface of the rotor and the housing, and brings the rotor into pressure contact with the housing by a magnetic attraction force generated in the magnetic circuit. Accordingly, a stable and proper braking torque can be applied against rotor vibration, to prevent a false output signal while idling. Furthermore, the amount of wear of a bearing for rotatably supporting a rotating shaft of the rotor can be reduced to improve durability of the rotation detecting device by reducing the braking torque during high-speed rotation of the rotor.

Abstract: A distance measuring apparatus of the target tracking type which reduces the amount of data to be processed to allow high rate processing on the real time basis so that a distance to a moving object such as an automobile can be measured while tracking the object. The distance measuring apparatus comprises a plurality of frame memories for storing quantized density data of an image for one frame obtained at a fixed interval of time by imaging a travelling road in a matrix of columns and rows. The quantized data is compared at the same coordinate points to produce density difference data. The density difference data is accumulated for the individual columns and rows in the direction of each column and row, respectively. A preceding vehicle is tracked in accordance with the accumulated column data, the distance to the vehicle in front is measured in accordance with the accumulated row data.

Abstract: A load weighing apparatus for weighing a weight of a load on a vehicle comprises an intervening element provided between a body frame and a suspension for transmitting the weight of the load to the suspension from the body frame. The intervening element is formed of a magnetic material and has a plurality of bore sections. An excitation winding is wound about the intervening element through ones of the bore sections, while a measurement winding is wound about the intervening element through the remaining bore sections. An electric power source for applying voltage is connected to the excitation winding. A measuring unit for measuring voltage across the measurement winding is connected thereto.