Reflection encoder, servo motor, and servo unit

A servo motor comprising:

• a motor configured to rotate a shaft;
• and
• a reflection encoder configured to be connected to the shaft to measure a position of the shaft, and
• the reflection encoder comprising:
• a rotating unit configured to be rotatably arranged around a rotating shaft center in accordance with rotation of the shaft and on which an incremental pattern is formed along a circumferential direction;
• and
• a board configured to be arranged opposite the rotating unit, and
• the board comprising:
• a light source configured to emit light toward the rotating unit;
• and
• an incremental light receiving element group configured to include a set including a plurality of incremental light receiving elements for receiving reflected light from the incremental pattern, the incremental light receiving elements of the set being separated and arranged in a line on the board in the circumferential direction of the rotating unit while placing the light source therebetween,
• wherein the incremental light receiving elements in the set respectively detect signals having corresponding phases in one period whose values increase sequentially.

A servo unit comprising:

• a motor configured to rotate a shaft;
• a reflection encoder configured to be connected to the shaft to measure a position of the shaft;
• and
• a control device configured to control rotation of the motor on the basis of the position detected by the reflection encoder, and
• the reflection encoder comprising:
• a rotating unit configured to be rotatably arranged around a rotating shaft center in accordance with rotation of the shaft and on which an incremental pattern is formed along a circumferential direction;
• and
• a board configured to be arranged opposite the rotating unit, and
• the board comprising:
• a light source configured to emit light toward the rotating unit;
• and
• an incremental light receiving element group configured to include a set including a plurality of incremental light receiving elements for receiving reflected light from the incremental pattern, the incremental light receiving elements of the set being separated and arranged in a line on the board in the circumferential direction of the rotating unit while placing the light source therebetween,
• wherein the incremental light receiving elements in the set respectively detect signals having corresponding phases in one period whose values increase sequentially.

A reflection encoder comprising:

• a rotating unit configured to be rotatably arranged around a rotating shaft center and on which an incremental pattern is formed along a circumferential direction;
• and
• a board configured to be arranged opposite the rotating unit, and
• the board comprising:
• a light source configured to emit light toward the rotating unit;
• and
• an incremental light receiving element group configured to include one or more sets of which each includes a plurality of incremental light receiving elements for receiving reflected light from the incremental pattern, the incremental light receiving elements in the set being arranged in a line on the board in the circumferential direction of the rotating unit, wherein
• the set includes the incremental light receiving elements that respectively detect signals having first to fourth phases in one period whose values increase sequentially,
• the set includes first and second sub sets whose first sub set includes the incremental light receiving elements corresponding to the first and third phases and second sub set includes the incremental light receiving elements corresponding to the second and fourth phases, and
• the first and second sub sets in the set are separated and arranged on the board in the circumferential direction of the rotating unit while placing the light source therebetween.

A reflection encoder comprising:

• a rotating unit configured to be rotatably arranged around a rotating shaft center and on which an incremental pattern is formed along a circumferential direction;
• and
• a board configured to be arranged opposite the rotating unit, and
• the board comprising:
• a light source configured to emit light toward the rotating unit;
• and
• an incremental light receiving element group configured to include a plurality of incremental light receiving elements for receiving reflected light from the incremental pattern, wherein
• the incremental light receiving elements are separated and arranged on the board in the circumferential direction of the rotating unit while placing the light source therebetween, and
• the incremental light receiving elements are arranged in a radiation direction whose curvature is smaller than that of the incremental pattern.