Abstract: An optical exposure system for a color video printer, comprising a microprocessor for controlling optical exposure for R, G and B video signals, a memory device for storing the R, G and B video signals by the frame, a drive control device for inputting R, G and B video data from the memory device and outputting signal voltages and gate voltages of fixed levels as drive control signals for optical exposure of a photosensitive medium, and a LCD panel for performing the optical exposure of the photosensitive medium in response to the drive control signals from the drive control device. The gradation number of exposure amount is determined by fixing levels of the signal voltages to fix transmitivities of R, G and B liquid crystal elements and determining the number of exposure times by R, G and B pixels to be proportioned respectively to the R, G and B data values.

Abstract: An exposure system for a color video printer capable of obtaining a uniform exposing to liquid crystal display panels for red, green and blue colors by common use of a light source being movably disposed. The exposure system includes liquid crystal display panels for red, green and blue colors disposed at an upper portion of a casing so as light being incident thereupon not to be interfered with each other, a light source for illuminating the liquid crystal display panels, a light source supporting and light-reflecting member being movable in the casing for containing the light source therein and reflecting the light toward only a desired panel, and a driving member for moving right and left the light source supporting and light-reflecting member.