Patent ID: 8146521

Claim:
A sewing machine comprising: a main shaft that drives a needle bar that is configured to hold a sewing needle; a sewing machine motor that rotary-drives the main shaft; a detection device that detects an actual movement distance of a piece of work cloth; a target pitch storage device that stores a predetermined length as a target pitch, is the target pitch being a target value of stitch pitches of the piece of work cloth; an agreement degree calculation device that calculates an agreement degree between the target pitch and a stitch pitch in actual sewing that is to be determined based on the actual movement distance of the piece of work cloth, which is detected by the detection device; and a notification device that notifies of the agreement degree calculated by the agreement degree calculation device, wherein: the detection device detects the actual movement distance of the piece of work cloth for each of a predetermined small lapse of time during a stitch formation period of time in which a needle drop point is formed next to a predetermined needle drop point; and the agreement degree calculation device calculates the agreement degree between: an accumulated value obtained by accumulating the actual movement distance of the piece of work cloth for each of the predetermined small lapse of time detected by the detection device during a predetermined lapse of time in the stitch formation period of time, and an accumulated value obtained by accumulating a target movement distance of the piece of work cloth for each of the predetermined small lapse of time which is computed based on the target pitch and a revolving speed of the main shaft during the predetermined lapse of time in the stitch formation period of time.