Abstract: A lower thread ending region detection apparatus prevents problems associated with false stitchings occurring from inability to detect lower thread's exhaustion during sewing operation. The lower thread ending region detection apparatus comprises: light control unit, which contacts a part of lower thread wound on a thread bobbin and activates or inactivates at least one of the functions of emitting light, reflecting light, passing light and blocking light, due to the effect of the physical movement force generated depending on whether the lower thread of the ending region is unwound; light receiving unit, which receives the light transferred out by the light control unit and outputs a detection signal; and control and notification unit, which analyzes the detection signal output from the light receiving unit to determine whether the lower thread has reached the ending region and outputs the result to the user.

Abstract: The present invention relates to a lower thread ending region detection apparatus (LTERDA) that prevents problems associated with poor quality and re-work resulting from false stitchings due to being unable to detect the exhaustion of the lower thread during the sewing operation.