Image forming apparatus
An image forming apparatus which forms an electrostatic latent image on a photosensitive drum, serving as an image carrier, develops the image using toners of a plurality of colors, and transfers a toner image onto a printing medium in accordance with an electrophotographic process. A toner consumption amount detection unit detects the toner consumption amount of each of the toners of the plurality of colors, a decision unit decides upon a color to form a patch, based on input image data and the detected toner consumption amount of each color, a patch sensor detects the density of a patch of the decided color by generating the patch at a predetermined position on the photosensitive drum serving as an image carrier outside an area to form a color image, and an adjustment unit adjusts the printing density based on the detected patch density.
1. An image forming apparatus which forms a color image by using a plurality of color toners in accordance with an electrophotographic process, the apparatus comprising:
a toner consumption amount detection unit that detects a toner consumption amount of each of the plurality of color toners;
a decision unit that decides upon a color for forming a patch based on a type of input image data and the detected toner consumption amount of each of the plurality of color toners;
a forming unit that forms the patch, by using a toner of the decided color, outside of an area to form a color image in accordance with the input image data;
a patch density detection unit that detects a density of the formed patch; and
an adjustment unit that adjusts a printing density based on the detected density of the formed patch.
2. The apparatus according to claim 1 , wherein the decision unit decides upon a color for a graphic image type.
3. The apparatus according to claim 1 , wherein the decision unit decides upon a color in which tone is considered to be an important type.
4. The apparatus according to claim 3 , wherein the tone is gradation.
5. The apparatus according to claim 1 , wherein the toner consumption amount detection unit detects the toner consumption amount based on the input image data.
6. The apparatus according to claim 1 , wherein the toner consumption amount detection unit detects the toner consumption amount based on a size of an input image indicated by the input image data.
7. The apparatus according to claim 1 , wherein the forming unit forms the patch in an area between a plurality of color images formed on an image carrier.
8. The apparatus according to claim 1 , wherein when the area to form the color image is small, the forming unit forms the patch at an end portion of a photosensitive drum, and
wherein when the area to form the color image is large, the forming unit forms the patch in a patch formation area which has been reserved before forming the color image.