Monitor Selection Technique for Light Pen Functions
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
This article describes a technique for determining which of several adjacent monitors with which a single light pen is being used. The technique, performed in software, eliminates the need for a multi- position hardware switch which would otherwise be used to perform the same function. The technique is employed in a video conferencing system having a plurality (usually 3 or 4) monitors, all of which derive synch signals from a system clock. The technique permits the user of a light pen to work with any of the monitors. Referring to the flow chart, monitor selection is initiated when the user touches the light pen to any of the monitors. The closure of a switch within the light pen is an indication that the user wishes to perform light pen functions at one of the monitors.