Patent ID: 8264380

Claim:
A manufacturing method for a code wheel for a rotary encoder, the code wheel including, in a central portion, a hole into which a rotary shaft of a rotary member is fitted and a code portion including a radial code pattern in a circumferential edge portion, the method comprising: forming the code portion and a reference circle in a plate so that the reference circle has a radius larger than a radius of the hole by a tolerance of deviation between a center position of the code portion and a center position of the hole, and the reference circle has a same center as that of the code portion; and forming the hole in the plate in which the code portion and the reference circle are formed, so as to be contained in the reference circle, wherein the radius of the reference circle is set to be able to tolerate the deviation even when a circumference of the reference circle and a circumference of the hole overlap with each other.