JPS644733A - Crt exposing method - Google Patents

Abstract

PURPOSE:To prevent the lowering of lightness in developing peripheral part caused by the dropping of the light quantity in the peripheral part by raising the luminance in the peripheral part of a CRT screen and executing image- formation and exposure on a photosensitive recording medium with an optical lens. CONSTITUTION:X and Y components, in a coordinate system on a fluorescent screen 5, of a point where an electron beam emitted with image signals synchronizing with horizontal and vertical deflection signals applies are detected from the respective signals by a beam position detection circuit 10, so that the distance L from a center O is calculated. The increase of a voltage to an electron gun 4 from a matrix circuit 7 which applies the normal luminance with the calculated distance L is executed under the control by a voltage correction circuit 11 by using an operational amplifier 12. As for the projected fluorescent screen 5, the image-formation is executed on the photosensitive recording medium 9 with the optical lens 8. Thus, the lowering of lightness caused by the dropping of the light quantity in the peripheral part of the optical lens does not occur in the developing peripheral part on the exposed photosensitive recording medium.