In one embodiment of the present invention, a display module includes a display screen divided in a vertical direction into screen regions in each of which an image can be independently displayed. Image data is collected from a region of interest on a substrate at multiple beam tilts. The distress sounds are pre-programmed into the device so that only pre-selected distress sounds cause the mobile telephone to be contacted. The components held by the source are then located relative to the global reference system based upon the determined location of the source. The offset generator circuit receives the output signal and, in response, adds an offset to the input terminals of the differential amplifier.