Scanning method for detecting documents

摘要

A scanning method for detecting documents is provided an optical scanning device. The optical scanning device is capable of scanning an object by a reflective scanning mode or a transmittal scanning mode. Then obtaining an image signal of the object by either the reflective scanning mode or a transmittal scanning mode with the retrieved scanning mod. Comparing the image signal with a pre-determined signal will result in an implementation from one of the reflective scanning mode or the transmittal scanning mode.