BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an image forming apparatus such as a printer, copying machine, recording device, fax machine, or the like that forms an image based on an image signal, and to a color material cartridge.

Description of the Related Art

In recent years, printing by a color image forming apparatus employing a method such as an electrophotographic method or an inkjet method has become widespread. In the color image forming apparatuses, using a color material such as toner or ink of a plurality of colors is common. In the color image forming apparatuses, an image signal normally configured by RGB color signals or the like is inputted, the image signal is converted into color signals of the color material colors (CMYK, for example) of an image forming apparatus, and then a color image is formed on a print medium by overlaying color materials of amounts based on the respective color signals. At this time, a color conversion parameter for converting inputted color signals into color material colors are decided to be appropriate values based on color development of each color material of the color image forming apparatus.

The color conversion parameter is generally specified on the premise that invariably the tint of the color material will not change. However, there are cases where the tint of the color material changes due to an improvement in a capability such as an improvement in color reproducibility and cases where a change in the tint of the color material arises depending on when the cartridge in which the color material is stored was manufactured, or the like. In such a case, the tint will change upon a cartridge exchange, and the color formed on the print medium will change to a color not desired by the user even if color signals after color conversion have the same values.

In relation to the above-described problem, a printer cartridge equipped with a compressed multi-dimensional color table is disclosed in Japanese Patent Laid-Open No. 2017-527860. Also, Japanese Patent Laid-Open No. 11-305498 discloses a development cartridge in which, in addition to the date of manufacture and serial number, color conversion coefficients is stored, and discloses an image forming apparatus that reads color conversion coefficients corresponding to a combination of the serial numbers of the respective cartridges from the latest cartridge mounted on the image forming apparatus.

However, the multi-dimensional color table in the method of Japanese Patent Laid-Open No. 2017-527860 must be a huge table in order to guarantee accuracy. For this reason, there is a problem that the space for storing the table, even if compressed, becomes enormous and that the cost of a storage medium increases. Furthermore, there is a problem in that when a color table is stored in a specific printer cartridge, the color changes if the tint of the toner of another cartridge which does not have a color table changes.

Also, in the method of Japanese Patent Laid-Open No. 11-305498, when the number of cartridges of a series increases, the number of cartridge combinations increases accordingly, and the space for color conversion coefficients also increases. As a result, there is a problem in that the space for storing color conversion coefficients becomes enormous and that the cost of a storage medium increases. Additionally, there is a problem that management of cartridges becomes complex when the number of cartridge combinations increases and the cost of management also increases.

SUMMARY OF THE INVENTION

The present invention has the following configuration.

According to the first aspect of the present invention, there is provided an image forming apparatus for which a color material cartridge that contains color material and has a storage unit can be attached/detached, the image forming apparatus operable to form, based on an input image signal, a visible image according to color material on a print medium, the apparatus comprising: an obtaining unit configured to obtain color material information related to a color of the color material stored in the storage unit; a generation unit configured to generate a color conversion parameter based on the color material information obtained by the obtaining unit; and a color conversion unit configured to convert the input image signal into a color signal for the color material by using the color conversion parameter, wherein the generation unit, in a case where the color material information is not changed, does not generate the color conversion parameter, and in a case where the color material information changed, generates the color conversion parameter based on the color material information after the change.

According to the second aspect of the present invention, there is provided a color material cartridge that can be attached/detached with respect to an image forming apparatus operable to perform image formation based on a color signal resulting from conversion from an input image signal, the cartridge comprising: a storage unit configured to store color material; and a storage unit configured to store color material information related to a color of the color material, wherein the color material information is information for generating, based on the color material information, a color conversion parameter for converting an input image signal that is inputted into the image forming apparatus into a color signal of the color material, and the color material information is used for generation of the color conversion parameter by the image forming apparatus in a case where the color material information changed for a color material cartridge that was mounted to the image forming apparatus.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

