Apparatus for simulation of visual fields of view

Claim 1

In apparatus for simulating a visual field of view for training in a battle situation including means for displaying the image of a background on a TV-monitor in the field of view of an optical system used by a person to be trained, said image of said background being digitally stored, and including changeable addressing means whereby different partial cut-outs from said background image may be selectively displayed on said TV-monitor, the improvement comprising: a buffer storage memory; means for loading a first partial cut-out from said background image into said buffer memory, said means for loading including means for loading a subsequent partial cut-out from said background having a changed address in such manner that so much of said subsequent partial cut-out as overlaps said initial partial cut-out remains in said buffer memory with only so much of said subsequent partial cut-out as differs from said initial cut-out being loaded into the buffer memory, replacing so much of said first partial cut-out as differs from said subsequent partial cut-out, said loading means including first addressing means for selectively controlling said loading of said buffer memory; and readout means for selectively coupling said buffer memory to said TV-monitor, said readout means including modulo (m-1) row address counter (37) and a modulo (n-1) column address counter wherein m and n are numbers representing powers of two.