Patent ID: 7664600

Claim:
An obstacle detection device, comprising: a plurality of detection units which are respectively assigned to a plurality of detection areas to perform signal transmission-reception operations with respect to the detection areas, the signal transmission-reception operation of each said detection unit including sending of a detection signal to a respectively associated detection area allotted thereto and reception of a reflection signal from the detection area allotted thereto; an electronic control unit having a central processing unit, memory and input/output ports, said electronic control unit being configured to function as an operation control unit which controls a detection unit to perform a signal transmission-reception operation responding to at least one of a plurality of kinds of operation timing signals, which are repeated at a predetermined periodicity; and said electronic control unit also being configured to function as a determination unit which counts a number of continuous reception times of the reflection signal of a detection unit, and determines detection of an obstacle in the detection area allotted to a respectively associated detection unit when the number of the continuous reception times is larger than or equal to a predetermined value, wherein the signal transmission-reception operation of a detection unit which commences to receive the reflection signal is provided by the operation control unit with an operation timing signal having a periodicity shorter than the predetermined periodicity, and wherein when the reception of the reflection signal by a detection unit dies before the number of the continuous reception times thereof reaches the predetermined value, the periodicity of the operation timing signal to which that detection unit responds is converted by the operation control unit back into the predetermined periodicity.