Encoder system having function of detecting origin position, machine tool, and transfer apparatus

An encoder system comprising:

• a supporting member including a plurality of marks;
• a first sensor and a second sensor provided so as to be shifted from each other by a first distance in a moving direction of the supporting member and configured to be capable of reading the plurality of marks;
• and
• a calculation processing unit configured to perform a calculation processing of detected signals of the first sensor and the second sensor,
• wherein the calculation processing unit calculates a first time that is required for one mark of the plurality of marks to move the first distance and a second time that is required for two adjacent marks of the plurality of marks to pass a detection position of one of the first sensor and the second sensor while the supporting member moves relatively to the first sensor and the second sensor, and
• the calculation processing unit determines that a mark pattern that is used to calculate a first index is an origin mark pattern when the first index calculated based on the first time and the second time corresponds to a second index that characterizes an origin position.