Patent ID: 7231160

Claim:
A printing device that is capable of printing in a color print mode and printing in a monochromatic print mode, said printing device comprising: multiple toner cartridges that are respectively filled with toners of multiple colors used for color printing; a changeover mechanism that sequentially moves positions of the multiple toner cartridges to a development position, where each color toner image is formed on a photoreceptor with a supply of corresponding color toner from one of the multiple toner cartridges located at the development position; a mode identification module that identifies either the color print mode or the monochromatic print mode; and a changeover control module that controls said changeover mechanism, in response to identification as the color print mode by said mode identification module, to sequentially move the positions of the multiple toner cartridges to the development position and form respective color toner images on the photoreceptor, said changeover control module controlling said changeover mechanism, in response to identification as the monochromatic print mode by said mode identification module, to fix the position of a specific toner cartridge filled with a specific color toner used for monochromatic printing to the development position and form a monochromatic toner image on the photoreceptor; a frequency measurement module that measures a number of consecutive printing operations in the monochromatic print mode; and a measured frequency judgment module that determines whether the number of consecutive printing operations in the monochromatic print mode measured by said frequency measurement module reaches a preset number, wherein said changeover control module, in response to determination of said measured frequency judgment module that the measured number of consecutive printing operations in the monochromatic mode reaches the preset number, controls said changeover mechanism to once move the positions of the multiple toner cartridges and then fix the position of the specific toner cartridge filled with the specific color toner for monochromatic printing to the development position to form the monochromatic toner image on the photoreceptor.