Method and apparatus for keeping a document in focus during noncontact scanning

摘要

This invention relates to a scanning device for scanning a document such as a photograph using an image sensor device that uses optics that may have a narrow depth of focus, the scanning avoiding contact of the document by the image sensor device during scanning. That is, the focal volume of the sensor device is at a distance from the image sensor device. The scanning device includes a positioning mechanism that maintains the front surface of the document in the focal volume during scanning.