| 摘要 |
PROBLEM TO BE SOLVED: To provide a sewing machine which is equipped with a detecting device for bobbin thread remaining amount of the sewing machine to minutely determine changes of a remaining amount of a bobbin thread wound around a bobbin in a stepwise manner. SOLUTION: The detecting device 21 for detecting a remaining amount of the bobbin thread T wound around the bobbin 1 includes a detecting rod 12 which is disposed to advance from an opening part of a hook to the shaft side in the direction of the diameter of the bobbin with the consumption of the bobbin thread while the end part abuts on the bobbin thread T wound around the shaft of the bobbin 1 and has a reflective surface 14 on the peripheral surface, a light source for emitting light to the reflective surface, and an image sensor for receiving the light of the light source reflected by the reflective surface. Further, the device 21 is equipped with: an image processing circuit for sequentially acquiring a moving amount of the detecting rod based on the image continuously formed by the image sensor; and a control part which stores a plurality of threshold values of the moving amount of the detecting rod for the remaining amount of the bobbin thread, performs the cumulative operation of the moving amount detected by the image processing circuit, stores the cumulative moving amount in a storage part, and detects the remaining amount of the bobbin thread by comparing the cumulative moving amount with the threshold values. COPYRIGHT: (C)2009,JPO&INPIT
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