Gain Saturation for MRFME is where searching in more previous frames offers very limited or even no performance gain. Consequently, it is possible to provide the membrane member that is sufficient in strength and is hard to be deformed by heat. The outputs from the photoelectric conversion elements in one group are read out simultaneously in response to the clock signal generated from the controller, thereby attaining a high speed reading of a document. In addition, the method may include establishing a trustworthiness exception that causes the security system to treat the file as trustworthy on the computing system that created the file.