Abstract: The present invention accomplishes the above objects by employing a display having the capability to emit light and form images viewable from both the front and back of the display. The invention also shutters the images displayed on the front and back of the display so that the images can be correctly displayed depending on the viewpoint of the viewer. Text and images displayed such that they are seen from both the front and back of the display appear differently to the front and rear viewer. Electronic shutters are placed between the display and both the front and rear viewers so that they can be flashed on and off fast enough to provide a stable image appearing to each viewer. The shutters also flash slow enough so that display data can be rewritten to provide each viewer with a correct image. The correct image can be either the corrected image of that image seen by the opposing viewer, or a completely separate image. In this way, simultaneous images appear to both the front and rear viewer.

Abstract: In a data transmission system comprising of a transmitting unit, a plurality of remote devices, and one or more serial communication links interconnecting the devices to the transmitting unit the polarities of a serially transmitted test signal and a locally generated control signal are used to provide unique addresses for identical devices connected to the transmitting unit. The technique provides a dynamic scheme for assigning addresses to identical devices.

Abstract: A dual threshold comparator circuit includes a comparator amplifier for comparing an analog input signal to a threshold waveform. The threshold waveform is generated in a circuit which includes positive and negative peak detector circuits and a slope detector circuit, all of which are connected to the analog signal source. A voltage divider is connected across the output of the positive and negative peak detector circuits. The threshold input to the comparator amplifier is connected to the common junction of first and second serially-connected impedances in the voltage divider. At the beginning of a particular half cycle of the analog input signal, the voltage across the voltage divider is equal to the difference of the most recent positive and negative peak voltages. The slope detector alters the effective impedances in the voltage divider to cause the threshold voltage to be equal to 25 or 75% of the total difference voltage, depending upon the slope of the analog signal.