Sewing machine, computer readable medium storing thread tension adjustment program for sewing machine, and thread tension evaluation unit

Abstract

A sewing machine including an image capturing unit disposed at a position capable of capturing images of the stitches formed on the workpiece cloth and capturing images of the stitches at least from either upper and undersides of the workpiece cloth; an extracting section that extracts, from the image data of the stitches captured by the image capturing unit, a region occupied by an opposite side thread appearing at an interlace of the needle thread and the bobbin thread; a calculating section calculating an area of the extracted region; an evaluating section that evaluates a tension balance between the needle thread and the bobbin thread based on the area calculated by the calculating section; and a controller controlling the thread tension adjustment mechanism to modify the tension balance of the stitches based on a result of evaluation by the evaluating section.