Patent ID: 7236276
Filing Date: 2007-06-26
Classification: H04N

Abstract:
1. An image forming apparatus comprising: a pattern forming portion which reads gradation pattern information stored in a predetermined storage area and forms an image according to the gradation pattern information on an image recording medium; a first generating portion which reads the image according to the gradation pattern information on the image recording medium formed by the pattern forming portion by using a scanner, and generates a first gamma correction table on the basis of the read image information; a first printing portion which reads the gradation pattern information stored in the predetermined storage area, corrects the gradation pattern according to the first gamma correction table generated by the first generating portion, and prints an image according to the corrected gradation pattern information on an image carrier; a storage portion which detects a density of the image printed on the image carrier by the first printing portion, with a sensor for the amount of adhered toner, and stores the density of the image as a reference value of density in a storage area; a second printing portion which reads the gradation pattern information stored in the given storage area at an arbitrary timing, corrects the gradation pattern information with the first gamma correction table generated by the first generating portion, and prints an image according to the corrected gradation pattern information on the image carrier; a calculating portion which detects the density of the image printed on the image carrier by the second printing portion, with the sensor for the amount of adhered toner, compares the density of the image to the reference value of density stored in the storage portion, and calculates density deviation; a second generating portion which generates a newly second gamma correction table on the basis of the density deviation which said calculating portion has calculated; and an image forming portion which reads image information on an original with the scanner, corrects the read image information with the gamma correction table formed by the second generating portion, and forms an image based on the corrected image information on the image recording medium.