A multi-photocathode image converter

A photoemissive image converter that transforms optical images into hard copy has been designed and evaluated. The device is powered by a single dc potential and requires no focus or deflection. The image converter consists of a vacuum envelope containing an input window, a collector anode, and-an array of fine metal pins sealed through a wall of the device. By selective deposition, separate photocathodes are simultaneously deposited onto the inside end of each one of the thousands of pins in the array, making each one individually photosensitive.