Patent ID: 7190536

Claim:
A process for making a unitary color filter disc, comprising: preparing a disc member having a central hole, an outer periphery around said central hole, and an annular surface extending between said central hole and said outer periphery; providing a plurality of differently colored segments on said annular surface, wherein each of said colored segments is provided by partially masking said annular surface to expose a part of said annular surface and by directly depositing a coloring film on said part of said annular surface; providing a plurality of lateral masking plates each having a cutout part, wherein each of said lateral masking plates is placed concentrically over said annular surface to partially mask said annular surface and to expose said part of said annular surface, and wherein each of said masking plates has a circumferential outer periphery, said cutout part extending inwardly from said circumferential outer periphery and being formed as a truncated sector shape; providing a graduated masking plate which has a plurality of annularly spaced apart graduation holes; placing concentrically said graduated masking plate over said surface of said disc member; and forming directly graduation marks through said graduation holes on said surface within a region surrounded by said differently colored segments.