Lumatron: A high-resolution storage and projection display device

The Lumatron is a high-resolution storage and projection display device that separates the functions of light generation and modulation that are combined in the normal CRT or DVST. The modulation function is achieved in a single vacuum chamber by the formation of a depth-modulated diffraction pattern in a deformable medium with a fine electrostatically focused and deflected electron beam. The illumination function is provided by a single-lens schlieren optical system external to the vacuum. The electron beam and light paths in the Lumatron are coaxial and the maximum voltage required by the device is 7.5 kV. Permanent storage and continuous readout without degradation for more than 24 h is possible, and yet the stored information can be intentionally erased in less than 1 s. Resolution in excess of 1800 TV lines/in at the storage surface has been measured and full 10-step grey scales have been stored and projected. Once an image is stored in a Lumatron, the only power required to generate the display is that required by the light source. In a demountable version of the projector, the storage surface can be easily removed and the stored pattern displayed in a remote schlieren projector without degradation.