SEWING MACHINE

摘要

PURPOSE: Provided is a device detecting residual quantity of a bottom yarn on a sewing machine which is characterized by increased workability and reduced waste of the bottom yarn because of detecting time that the bottom yarn is exhausted. CONSTITUTION: The device detecting residual quantity of the bottom yarn is comprised of: the bottom yarn setting in a bottom yarn case unit(1); the bottom yarn case unit passing light through the inside; a bottom yarn detecting device irradiating the light to the bottom yarn, and detecting residual quantity of the bottom yarn; and a warning device(60) alarming exhaustion of the bottom yarn.