Image forming apparatus and printing method therefor

An image forming apparatus comprising:

• an apparatus main body;
• an operation panel that is provided in the apparatus main body and used for instructing printing of an image;
• plural paper feeding cassettes that store paper for color printing or paper for monochrome printing on which the image is printed;
• a cassette-paper-correspondence recognizing unit that is provided in the apparatus main body and recognizes a cassette-paper correspondence relation indicating whether the paper stored in the plural paper feeding cassettes is the paper for color printing or the paper for monochrome printing;
• a paper-feed control unit that specifies, when the image instructed to be printed is an image suitable for color printing, a paper feeding cassette in which the paper for color printing is stored with reference to a cassette-paper correspondence table stored by the cassette-paper-correspondence recognizing unit;
• and
• a printing unit that feeds the paper stored in the paper feeding cassette specified by the paper-feed control unit and prints the image.

A printing method for an image forming apparatus for feeding, when printing of a created image is instructed by a user from an operation panel provided in an apparatus main body, paper from any one of plural paper feeding cassettes and printing the image, the printing method comprising:

• discriminating whether the image instructed to be printed is an image of a color original or an image of a monochrome original;
• specifying, when it is discriminated that the image is an image of a color original, a paper feeding cassette in which paper suitable for printing of the image of the color original is stored with reference to a cassette-paper correspondence table indicating whether the paper stored in the plural paper feeding cassettes is the paper for color printing or the paper for monochrome printing;
• and
• feeding the paper stored in the paper feeding cassette and printing the image instructed to be printed.

A printing method for an image forming apparatus comprising:

• receiving basis weight of paper stored in plural paper feeding cassette;
• measuring paper thickness of the paper stored in the paper feeding cassettes;
• calculating, from the measured paper thickness and the received basis weight, density of paper stored in a specific paper feeding cassette;
• comparing the calculated density with a predetermined value;
• storing a cassette-paper correspondence relation as a table by associating the specific paper feeding cassette with the paper for color printing when it is judged that the density of the paper is equal to or larger than the predetermined value and associating the specific paper feeding cassette with the paper for monochrome printing when it is judged that the density of the paper is smaller than the predetermined value;
• specifying, when printing of an image of a color original is instructed, a paper feeding cassette in which the paper for color printing is stored with reference to the cassette-paper correspondence table;
• and
• feeding the paper stored in the paper feeding cassette and printing the image instructed to be printed.