Patent attributes
An apparatus and method for detecting a cam phase of an engine provided with a variable valve timing mechanism able to vary a rotating phase of a camshaft relative to a crankshaft of the engine, which apparatus and method can detect the rotating phase in a short cycle. There is provided a cam angle sensor having a configuration of outputting a cam angle signal at each time when the camshaft rotates by a unit angle. At the same time, by lengthening an output cycle of the cam angle signal on a part thereof or by using a second cam angle sensor able to detect a reference cam angle position, a cam angle position to which individual cam angle signal corresponds is detected. Then, the rotating phase of the camshaft relative to the crankshaft can be detected, based on the detection result of the cam angle position based on the cam angle signal.
