Image Number 17 for United States Patent #5136148.
A speed detection apparatus includes a projection unit for repetitively projecting a pulse beam toward an object. A light-receiving unit is arranged to be separated from the projection unit by a base length, receives the pulse beam reflected by the object, and generates an output according to the light-receiving position. A distance calculation unit calculates a distance signal according to a distance to the object upon reception of an output from the light-receiving unit. An integration circuit integrates the distance signal every time the pulse beam is projected. A speed calculation unit calculates a moving speed of the object on the basis of an output from the integration circuit.