Patent ID: 7301669

Claim:
A color printing apparatus for printing by mixing a plurality of primary colors, comprising: a printer data receiver for receiving a print instruction of print data issued from an application program, and for rasterizing said print data to separately receive con-tone/multi-bits bitmap data and bi-tone/single-bit bitmap data, respectively both made up of said print data, from a high-ordered apparatus; a page memory for independently storing thereinto both said con-tone/multi-bits bitmap data and said bi-tone/single-bit bitmap data; a control unit for executing a control operation in such a manner that said con-tone/multi-bits bitmap data is converted into con-tone/multi-bits print data, said bi-tone/single-bit bitmap data is converted into bi-tone/single-bit print data, and at least one of said con-tone/multi-bits print data and said bi-tone/single-bit print data is stored into said page memory in a bitmap format; and an output control unit for reading at least any one of said con-tone/multi-bits print data and said bi-tone/single-bit print data from said page memory, and for logically synthesizing said print data with each other to output the synthesized print data to a color printing unit, wherein said control unit designates resolution of said bi-tone/single-bit bitmap data as first resolution equal to the output resolution of the color printing unit, and designates resolution of said con-tone/multi-bits bitmap data as second resolution equal to 1/n of said first resolution, and also stores both said bi-tone/single-bit bitmap data and said con-tone/multi-bits bitmap data into said page memory; and said output control unit includes an enlarging circuit for enlarging said con-tone/multi-bits bitmap data having said second resolution to said first resolution to logically synthesize said enlarged con-tone/multi-bits bitmap data and said bi-tone/single-bit bitmap data and output synthesized bitmap data to the color printing unit.