Patent ID: 6464905
Filing Date: 2002-10-15
Classification: B44C,G02B

Abstract:
A method of performing a uniform illumination pattern in a back-light plate, the back-light plate, being substantially flat and transparent, comprising two parallel illuminating faces and an incident side on one side of the back-light plate, and when a visible light emits from the incident side into the back-light plate, the visible light further emitting out from the two illuminating faces of the back-light plate, the method comprising steps of:performing a manufacturing process to form a hole mask with a predetermined hole pattern; positioning the hole mask on one illuminating face of the back-light plate; and performing a sand-blasting process so as to form a plurality of recesses on the back-light plate, each recess being no deeper than a predetermined depth; wherein a distance between one recess and its adjacent recess depends on a distance between the recess and the incident side of the back-light plate, and when the distance between the recess and the incident side is longer, the distance between the recess and its adjacent recess is designed shorter, and positions of holes in the hole mask match positions of recesses of the back-light plate, the plurality of such recesses form the uniform illumination pattern of the back-light plate, and when the visible light emits into the back-light plate, the plurality of recesses on the illuminating face make the emitted visible light uniformly illuminated.