Abstract: A display apparatus having a transparent image screen which contains a mosaic of four discrete images formed from pixels which are interwoven in a predetermined arrangement such that each of the images are selected by precise positioning of the screen in four different positions relative to a grid mask which masks out all but pixels of a selected image. A platen comprising a platen surface which is supported by a rib structure mounts the image screen and is moveable through a precise pattern for selecting the pixels, and thereby the image, to be projected. A pair of arms are coupled to the platen and an eccentric drive and are driven by the eccentric drive to advance the platen positively through the pattern.

Abstract: A laser package includes a laser with first and second spaced terminals and a layer between the terminals with properties of emitting light when voltage pulses are applied between the terminals. A current of a particular magnitude is produced between the terminals in the time periods between the voltage pulses. The voltage required to produce such current is dependent upon the layer temperature. Variations in this voltage produce variations in the rate of pulses from a thermoelectric cooler included in the laser package. Variations in the rate of such pulses from the thermoelectric cooler affect the rate at which heat is withdrawn by the thermoelectric cooler from the laser. A cooler body is disposed adjacent to the thermoelectric member and is constructed to pass a cooling fluid through the cooler body to cool the thermoelectric member. The cooling fluid passes through an inlet port to a plurality of channels converging at a central recess.