A New Measuring Method of Stitch Balance for Lockstitch Sewing Machine

A new measuring method of stitch balance for a lockstitch sewing machine is proposed. The stitch balance is estimated by the field of the bobbin thread appeared in a stitch hole. The visual field is measured quantitatively by dots of a picture area which is painted using a personal computer and a image scanner. The method has following special features ; 1) the many data can be processed in a short time, 2) the sewn fabrics is not cut and 3) the estimation is able to be used for a long continuous seam. But there is the problem that the color of the bobbin thread must be different from both one of the needle thread and the sewn fabrics.