(57) The invention relates to a sewing machine (10). The sewing machine (10) includes
a main shaft which is rotated by a motor (1) to move a sewing needle, a position detecting
means (14, 15) for detecting a rotation angle of the main shaft as a main shaft angle,
a thread cutting mechanism (30) having a movable knife (31), a thread cutting cam
(51) having a cam groove (51a) formed along a circumferential direction and rotating
in synchronization with the rotation of the main shaft, a cam follower (52) configured
to engage with the cam groove (51a) to move the movable knife (31) in accordance with
the cam groove (51a), a thread cutting actuator (56) which switches the cam follower
(52) between an engaging position and a disengaging position with respect to the thread
cutting cam (51), and a control means for controlling the thread cutting actuator
(56) and the motor (1). The control means includes an operation timing determining
means for determining an operation start timing of the thread cutting actuator (56)
or the motor (1), based on at least one of a rotation speed (v1, v2) of the motor
(1) for a thread cutting operation and a main shaft stopped angle (θ1) at which the
main shaft has stopped immediately before the thread cutting operation.
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