Abstract: An ultrasonic distance sensor transmitting from and receiving an ultrasonic wave with a single ultrasonic transmitting and receiving element to measure proximate distances such as vehicle floor heights or distances to obstacles or pedestrians approaching relative to a vehicle. The ultrasonic transmitting and receiving element is accommodated by means of a resilient member having beads, under pressure in a casing and secured therein, thus attenuating residual vibration which disturbs accurate measurement of the proximate distances. The beads also serve to prevent water from invading into the case. The sensor incorporates a protection circuit for preventing burn-out of an output transistor due to accidental prolonged transmission.

Abstract: A navigation system and method for guiding a vehicle along a selected route of travel to a destination from a starting point using a display unit. In the navigation system, a positional relationship between a start road branched from a first known branching point (a start intersection from which a guidance of the vehicle along the selected route of travel is initiated) and entrance direction of the vehicle toward the first known branching point is clearly and distinguishably displayed on the screen of the display unit after the selection of the route of travel from the starting point to the destination so that the vehicle can corectly enter the start road at the first known branching point even if it has reached the first known branching point via any arbitrary route of travel from the starting point.