| 摘要 |
PURPOSE:To detect an original securely without reference to the transparency of an original and whether dust, paper dust, etc., are present or not by providing a metal detection sensor at one side of an original conveyance path, and arranging a metallic member which projects rockingly into the original conveyance path at the opposite side. CONSTITUTION:While no original is present between a platen 7 and an original feed guide 8, a detection member 13a is positioned at an upper part by the downward gravitational force which operates on the weight part piece 13b of the metallic member 13 and comes close to the metal detection sensor 12, which transmits an output signal. The absence of an original is detected from the output of this metal detection sensor 12. When an original placed on the platen 7, a detection part piece 13a is rocked downward by the original against the righting moment of the weight part piece 13b and leaves the metal detection sensor 12. The output voltage of the metal detection sensor 12 varies in proportion to the distance to metal, so the output voltage of the sensor 12 drops in this case to detect the original being present between the platen 7 and original feed guide 8. |
