Macrophotograph of the display used to represent numbers on a calculator. The display consists of a strip of scintillating material which is divided into elements each of which may be independently given a positive potential. Above the strip, separated by a vacuum layer, is a negative electrode in the form of a grid. Electrons are torn from the grid to those regions of the scintillator with net positive charge, thus causing the emission of light. Numerals are reproduced by a microprocessor which activates a combination of the elements to create the desired figures. Magnification: x4 at 35mm size.