Abstract: A brightfield/darkfield microscope illuminator has two axicon mirrors and a third plane mirror for use with two light beams from different sources. An open shutter positioned in the path of one beam provides brightfield illumination. An open shutter positioned in the path of the other beam provides darkfield illumination. This illuminator easily switches between operation in the darkfield and brightfield modes, uses substantially all the light in one beam for darkfield illumination and easily balances the illumination between the two light sources.

Abstract: A direct view display device comprises a pair of conductive electrodes in spaced relationship and a recording medium having the properties of being both photo-ionizable and capable of electro-chemically producing colored species occupies the space between the electrodes. The display device is exposed to an optical pattern of radiation to which the recording material is sensitive to produce a latent image, and a potential is applied between the electrodes to produce a very dense image corresponding to the optical pattern. The image can be erased by reversing the potential between the electrodes so that the expose and enhance process can be repeated.