| 摘要 |
PURPOSE:To obtain the titled image sensor whose focal depth is deep, by moving a focus of the contact type image sensor by a distance of a focal depth portion or below of a rod lens array. CONSTITUTION:In case a focus of a lens has been aligned with a read surface 3 of a read original 2 of a contact type image sensor 1, floating from the read surface 3 of the rear original 2 is allowed only in a distance of a thin line part. Therefore, with respect to the read surface 3 of the sensor 1, when the lens focus is moved by a focal distance of the lens, the sensor has the focal depth by a range part of a thick line shown in the figure. That is, when the focus of the lens is moved by a focal distance portion from the original read part of the sensor 1, the sensor 1 comes to have focal depth of two times of the focal distance of the lens. On the other hand, when a shift quantity from the focus of the lens becomes large, its resolution is deteriorated, therefore, in the case of the sensor 1 of a structure in which the original scarcely floats from the read surface of the sensor 1, it is unnecessary to move the focus by a focus portion of the lens, and it will suffice that the focus is moved by a supposed distance.
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