Image forming apparatus and image forming method

An image forming apparatus for adhering a toner to a photosensitive member to form a toner image, and transferring the toner image on the photosensitive member onto a transfer member supported by a transfer member supporting member which is included in a transfer apparatus and is provided in contact with the photosensitive member, said image forming apparatus comprising:

• a first storing portion which stores gradation pattern information in advance;
• a first pattern forming portion which reads the gradation pattern information from the first storing portion, forms a toner image according to the read gradation pattern information on the photosensitive member, and transfers the toner image onto the transfer member by the transfer apparatus;
• a first generating portion which reads an image according to the gradation pattern information on the transfer member formed by the pattern forming portion and generates a first gamma correction table on the basis of the read image information;
• a second pattern forming portion which reads the gradation pattern information, corrects the gradation pattern information according to the first gamma correction table generated by the first generating portion, and forms a toner image corresponding to the corrected gradation pattern information;
• a second storing portion which detects density of the toner image formed on the photosensitive member by the first pattern forming portion and storing the detected density as a reference value of density;
• a third pattern forming portion which reads the gradation pattern information at an arbitrary timing, corrects the gradation pattern information by the first gamma correction table which the first generating portion generated, and forms a toner image according to the corrected gradation pattern information;
• a calculating portion which detects density of the toner image formed on the photosensitive member by the third pattern forming portion, and compares the detected density with the reference value of density stored in the first storing portion to determine a density deviation;
• a second generating portion which generates a second gamma correction table on the basis of the density deviation which the calculating portion has calculated;
• and
• an image forming portion which reads an original image using the scanner, corrects the read image information with the second gamma correction table formed by the second generating portion, forms a toner image based on the corrected image information on the photosensitive member, and transfers the toner image onto the transfer member by the transfer apparatus.

An image forming method for adhering a toner to a photosensitive member to form a toner image, and transferring the toner image on the photosensitive member onto a transfer member supported by a transfer member supporting member which is included in a transfer apparatus and is provided in contact with the photosensitive member, said image forming method comprising the steps of:

• storing gradation pattern information in advance;
• reading the gradation pattern information from the first storing portion, forming a toner image according to the read gradation pattern information on the photosensitive member, and transferring the toner image onto the transfer member by the transfer apparatus;
• reading an image according to the gradation pattern information on the transfer member formed by the pattern forming portion and generating a first gamma correction table on the basis of the read image information;
• reading the gradation pattern information, correcting the gradation pattern information according to the first gamma correction table generated by the first generating portion, forming a toner image corresponding to the corrected gradation pattern information, and transferring the toner image onto the transfer member supporting member;
• detecting density of the toner image transferred onto the transfer member supporting member by a sensor for the amount of adhered toner and storing the detected density as a reference value of density;
• reading the gradation pattern information at an arbitrary timing, correcting the gradation pattern information by the first gamma correction table, forming a toner image according to the corrected gradation pattern information, and transferring the toner image onto the transfer member supporting member;
• detecting density of the toner image transferred onto the transfer member supporting member by the sensor for the amount of adhered toner, and comparing the detected density with the reference value of density stored in the first storing portion to determine a density deviation;
• generating a second gamma correction table on the basis of the density deviation calculated;
• and
• reading an original image using the scanner, correcting the read image information with the second gamma correction table formed by the second generating portion, forming a toner image based on the corrected image information on the photosensitive member, and transferring the toner image onto the transfer member by the transfer apparatus.

An image forming method for adhering a toner to a photosensitive member to form a toner image, and transferring the toner image on the photosensitive member onto a transfer member supported by a transfer member supporting member which is included in a transfer apparatus and is provided in contact with the photosensitive member, said image forming method comprising the steps of:

• storing gradation pattern information in advance;
• reading the gradation pattern information from the first storing portion, forming a toner image according to the read gradation pattern information on the photosensitive member, and transferring the toner image onto the transfer member by the transfer apparatus;
• reading an image according to the gradation pattern information on the transfer member formed by the pattern forming portion and generating a first gamma correction table on the basis of the read image information;
• reading the gradation pattern information, correcting the gradation pattern information according to the first gamma correction table generated by the first generating portion, and forming a toner image corresponding to the corrected gradation pattern information;
• detecting density of the toner image formed on the photosensitive member by a sensor for the amount of adhered toner and storing the detected density as a reference value of density;
• reading the gradation pattern information at an arbitrary timing, correcting the gradation pattern information by the first gamma correction table, and forming a toner image according to the corrected gradation pattern information;
• detecting density of the toner image formed on the photosensitive member by the sensor for the amount of adhered toner, and comparing the detected density with the reference value of density stored in the first storing portion to determine a density deviation;
• generating a second gamma correction table on the basis of the density deviation calculated;
• and
• reading an original image using the scanner, correcting the read image information with the second gamma correction table formed by the second generating portion, forming a toner image based on the corrected image information on the photosensitive member, and transferring the toner image onto the transfer member by the transfer apparatus.

An image forming method comprising the steps of:

• reading gradation pattern information stored in a predetermined storage area and forming an image according to the gradation pattern information on an image recording medium;
• reading a gradation pattern on the image recording medium by using a scanner, and generating a first gamma correction table on the basis of the read image information;
• reading the gradation pattern information stored in the predetermined storage area, correcting the gradation pattern according to the first gamma correction table, and printing an image according to the corrected gradation pattern information on an image carrier;
• detecting a density of the image printed on the image carrier in the first printing step, with a sensor for the amount of adhered toner, and storing the density of the image as a reference value of density in a storage area;
• reading the gradation pattern information stored in the predetermined storage area at an arbitrary timing, correcting the gradation pattern information with the first gamma correction table generated in the first generating step, and printing an image according to the corrected gradation pattern information on the image carrier;
• detecting the density of the image printed on the image carrier with the sensor for the amount of adhered toner, comparing the density of the image to the reference value of density stored in the storage step, and calculating density deviation;
• generating a newly second gamma correction table on the basis of the density deviation;
• and
• reading image information on an original with the scanner, correcting the read image information with gamma correction table, and forming an image based on the corrected image information on the image recording medium.