Printing system and secure document printing method

A printing system, comprising:

• an input unit to input printing data;
• an output unit to print the printing data using main developers including a cyan (C) developer, a yellow (Y) developer, a magenta (M) developer, a black (K) developer, and a supplementary developer;
• a detection unit to detect whether a security mark is present in the printing data input by the input unit;
• a printing mode determination unit to determine a printing mode according to the detection result of the detection unit;
• a developer mode determination unit to determine a developer mode indicating whether to print the detected security mark using the main developers or the supplementary developer;
• and
• a control unit to control the output unit to print the printing data and the security mark according to the printing mode and the developer mode.

A secure document printing method, comprising:

• inputting printing data;
• detecting whether a security mark is present in the printing data;
• determining a printing mode according to the result of detection of the security mark;
• determining a developer mode indicating whether to print the detected security mark using main developers or a supplementary developer;
• and
• processing the printing data according to the printing mode and the developer mode.

A method of printing data, the method comprising:

• detecting whether the data to be printed comprises a security mark;
• determining whether the security mark is to be visibly printed on a document;
• and
• printing the security mark on the document using main developers or a supplementary developer according to the result of the determining.

An image forming apparatus, comprising:

• an input unit to input image data;
• a detection unit to detect whether a security mark is present in the image data;
• and
• an output unit to print the security mark using a supplementary developer when the detection unit detects the security mark in the image data.