Patent Number: 7,821,677

Title: Method and apparatus for image forming capable of accurately detecting displacement of transfer images and image density

Abstract: An image forming apparatus includes a plurality of image carriers, an image forming mechanism, a seamless belt-like intermediate transfer body or a transfer material carrier, a detection mechanism, and an optical detecting apparatus. The optical detecting apparatus includes at least a printed board, and a plurality of photodetectors formed of a light-emitting element, a light-receiving element and light-shielding members, which are mounted on the printed board. The optical detecting apparatus is disposed such that it detects a belt surface adjacent to rollers of the intermediate transfer body or the transfer material carrier, and either displacement of a transfer image or image density is detected by a plurality of photodetectors detecting pattern images which are transferred from the plurality of image carriers to the image transfer body or the transfer material carrier.

Inventors: Tanaka; Kayoko (Tokyo, JP), Fujimori; Kohta (Yokohama, JP), Hasegawa; Shin (Zama, JP), Kato; Shinji (Kawasaki, JP), Takeuchi; Nobutaka (Yokohama, JP), Watanabe; Naoto (Atsugi, JP), Hirayama; Yuushi (Sagamihara, JP), Ishibashi; Hitoshi (Kamakura, JP), Ariizumi; Osamu (Yokohama, JP), Enami; Takashi (Chigasaki, JP), Kobayashi; Kazumi (Tokyo, JP), Kobayashi; Shinji (Atsugi, JP), Uchida; Fukutoshi (Kawasaki, JP), Morimoto; Ryohta (Ebina, JP)

Assignee: Ricoh Company, Ltd.

International Classification: H04N 1/04 (20060101)

Expiration Date: 2018-10-26 0:00:00