Patent ID: 8836268

Claim:
A position sensing device configured to detect a position of a movable member being rotatable or linearly movable, the position sensing device comprising: a pulse signal output unit configured to send three-phase pulse signals, which have predetermined phase differences thereamong, according to a rotation or a linear movement of the movable member; a counter unit configured to store a count value and configured to add a first predetermined value to the count value or to subtract the first predetermined value from the count value and to add a second predetermined value to the count value or to subtract the second predetermined value, which is different from the first value, from the count value, according to an in-normal pattern, which is a combination of the pulse signals appearing when all the three-phase pulse signals are normal, and an in-malfunction pattern, which is a combination of the pulse signals appearing when one of the pulse signals among the three-phase pulse signals malfunctions; and a position detection unit configured to detect the position of the movable member according to the count value, wherein the counter unit is further configured to add the first predetermined value to the count value or to subtract the first predetermined value from the count value, when the movable member rotates or linearly moves and when the in-normal pattern changes to another in-normal pattern, and to add the second predetermined value to the count value or to subtract the second predetermined value from the count value, when the in-normal pattern changes to the in-malfunction pattern or when the in-malfunction pattern changes to the in-normal pattern.