| 摘要 |
<P>PROBLEM TO BE SOLVED: To deal with different models and to detect an upper stop position and a lower stop position of a needle with one sensor. Ž<P>SOLUTION: The sewing machine 1 includes: a pulley 3 which is fixed to a sewing machine main shaft 2 and rotates; reflecting members 42, 9 which are fixed to the pulley and reflect light; a fiber sensor 41 which is fixed to a sewing machine frame F, radiates light toward the reflecting members, and detect quantity of the reflecting light from the reflecting members; and an electronic circuit for converting the quantity of reflecting light detected by the fiber sensor into voltage. In the sewing machine 1, the reflecting members are formed so that straight line distances from a shaft center to an outer periphery differ at all outer peripheral positions. In the reflecting members, at a light receiving position where light radiated by the fiber sensor is received, the quantity of reflecting light reflected toward the fiber sensor changes as the rotation angle changes and, as the quantity changes, voltage output by the electronic circuit changes. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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