Patent US 4,385,461

This sequentially highlighting copy holder employs fields of light as the frame of reference for an operator of a keyboard machine in keeping the place in the text of a document page. The page is affixed upon the copy holder for processing and is illuminated, portion by portion, as the place in the text advances. In one place keeping function the perceived effect of this highlighting delivered in sequence is that of a slender field of light slowly descending the document page. In another, the field of light disappears as a second field appears lower on the page, overlapping the position of the first field of light and disappearing in turn as a third field appears, overlapping the position of the second, so that as the place in the text moves downward the field of light moves with it in salient changes of position, holding to the moving place of attention in the text. In yet another function, ongoing input entered into the keyboard machine sets the downward pace of the field of light. In one of the other functions, large and small undivided portions of the text are highlighted for such special applications as the processing of batches of short forms. The electronic manual, electronic mechanical and microprocessor embodiments reserve, for the operator, overriding control of both the rate of movement and the intensity of the place keeping field of light.