Patent ID: 6907342

Claim:
An apparatus for determining the crank angle of an engine crankshaft, wherein the crankshaft rotates in a first direction and in a second direction, wherein the second direction is opposite to the first direction, the apparatus comprising: indications located at predetermined angular intervals on the crankshaft, wherein each indication rotates integrally with the crankshaft along a path and passes near a detecting zone during crankshaft rotation; a detector device for detecting the passage of the indications, the detector device being located in the vicinity of the path, wherein the detector generates at least two signals, the statuses of which vary between a first state and a second state as the indications pass by; direction determining means for determining the statuses of the signals and for determining the rotation direction of the crankshaft on the basis of the statuses of the signals; and a control means for keeping a count based on the number of indications detected by the detector device and for controlling the engine based on the count.