A sheet folding and trimming apparatus for a booklet maker or bookbinder includes a folding apparatus and a sheetwise trimming apparatus configured to trim the folded sheet from the folding apparatus on three unfolded sides of the sheet in a sheetwise manner. The apparatus has a barrier driving controlling unit, a display controlling unit, and a display mode decision unit to decide a display mode of an image to be displayed on the panel. Thus, it is possible to maintain a toner concentration within the development device within a predetermined range without the toner being dispersed and an image formation speed being reduced even if an image having a high print rate is formed. The models are then analyzed in conjunction with pre-specified rules about the routines to determine if the routine call posses one or more of pre-selected vulnerabilities. The TEM is equipped with an objective lens for guiding a beam of electrons to a sample, a diffraction plane in which at least a beam of unscattered electrons is focused and a structure to enhance the Contrast Transfer Function which is situated in the diffraction plane or an image thereof.