A moving area detecting circuit detects a moving area of image information S. The polyolefin-based composite resin composition having a low coefficient of linear thermal expansion not only has excellent mechanical rigidity, impact resistance, heat resistance, injection moldability, product flatness, and dimensional stability, but also has a low shrinkage, a low coefficient of linear thermal expansion, and a low heat sag. The edge of the lower cover extends outward to form a circular protruding edge. Further, the drainage hole is formed so as to gradually slope from the electrical wire receiving portion toward the ground surface. Each segment is suitably compact to be easy stowed. With this configuration, the segment of the linear conductor connected to the feed point provides a driven element, while the other end of the linear conductor opposite to the feed point connected end is electrically open so that the segment of the linear conductor extending beyond the cut portion provides a parasitic element.