| 摘要 |
PROBLEM TO BE SOLVED: To obtain image data high in quality even if a document surface to be read slants to the image pickup element surface of an image pickup device. SOLUTION: This image pickup device is equipped with a distance measuring sensor 104 which measures the distance between the element surface of the image pickup element and the document surface, a tilt information detecting means 112 which detects the angle of the document surface to the element surface, a movement frequency arithmetic means 110 which calculates how many times an imaging optical system needs to be rotated for focusing on all ranges on the document surface to be picked up respectively from the distance information and tilt information detected by the distance measuring sensor and tilt information detecting means, and a lens driving means 107 which moves the imaging optical system along its optical axis according to the frequency calculated by the movement frequency arithmetic means. Consequently, all the image pickup areas are positioned within the depth of focus and a document image focused in all the areas on the document surface is read. |
