| 摘要 |
PROBLEM TO BE SOLVED: To provide an object sensing device for photo-electrically detecting an object crossing a curtain of light and lowering the cost and simplifying the installation by decreasing the number of elements constituting the curtain of light. SOLUTION: In the object sensing device, one light projecting and receiving means is formed by a projector for forming a plate-like light flux expanded like a fan and a light receiver disposed on the side of the light projector. The projecting and receiving means is installed in a part of a passage for passing the object, and a belt-like recurrence reflecting sheet is stuck to the inner periphery of the section of the passage, facing the projecting and receiving means, whereby the light emitted from the projecting and receiving means is returned to the projecting and receiving means. Thus, the object is sensed from lowering of output of a photo detecting element when the object crosses the curtain of light formed by the projecting and receiving means. COPYRIGHT: (C)2004,JPO |
