PURPOSE: To enable to detect a hole or an object exceeding the specified size precisely by a method wherein the multiple photoelectric conversion elements comprising the thin film semiconductors are arranged in two parallel rows so that the center of the element of one row is opposed to the gap between the the adjoining elements of the other row.
CONSTITUTION: The two rows 21, 22 of photoelectric conversion elements are shifted and arranged in parallel so that the center of the element 7 is opposed to the gap 23 between the adjoining elements of the other row. Through said arrangement, the projection on the detected region of the detected object shifting in the P direction passing the gap between the adjoining elements of one row also passes through the center of the element of the other row enabling to receive the output signals corresponding to the size of the detected region. Furthermore, assuming the detected region to be circular, the overlapping width L of the opposing element may be acceptable if said width L exceeds the depth X of the detected part of the element so that the overall detected region may be projected on either element of either row in either time even if the projection passes through the point shifting from the center of the element.
FUJISAWA HIROBUMI
UCHIDA YOSHIYUKI
FUJI ELECTRIC CO LTD