Canon Kabushiki Kaisha

Masatake Usui

Hiroki Eguchi

Hideyuki Yano

Hiroshi Kita

Michio Uchida

Shun-ichi Ebihara

Masaki Hirose

Ken Yokoyama

Hiroshi Mano

Noriaki Sato

Akihiko Takeuchi

Akira Kato

Kazuhiro Funatani

Akira Kuroda

Takaaki Tsuruya

Minoru Hayasaki

Akihiko Uchiyama

Aoji Isono

Atsuyoshi Abe

Yuki Nishizawa

Keisuke Mochizuki

Tetsuya Sano

Katsuhiko Oba

Yusaku Iwasawa

Yasuo Yoda

Yasunari Kobaru

Kenya Ogawa

Shunichi Ebihara

Hideki Hashimoto

An image forming apparatus includes a photosensitive drum and an exposure unit for exposing a surface of the photosensitive drum to form an image by a first exposure amount. In a rotational axis direction of a charging portion, a width of a transfer portion is shorter than that of a developing portion, a width of the transfer portion is shorter than that of the charging portion and an end portion of the surface includes a non-transfer area in contact with the charging portion and not in contact with the transfer portion. The voltage having the normal polarity is applied to the transfer portion when no recording material exists at the transfer portion, and the exposure unit exposes an area, including the non-transfer area of the surface that has passed through the transfer portion during application of the voltage, by a second exposure amount less than the first exposure amount.

Image forming apparatus

An image forming apparatus includes a rotatable photosensitive member, a charging member, a developing member, a transfer member, a voltage applying portion, and a controller. The controller is capable of changing a trailing end voltage to a first trailing end voltage lower than a transfer voltage applied to the transfer member by the voltage applying portion when a toner image is transferred from the photosensitive member to a recording material and to a second trailing end voltage higher than the first trailing end voltage. In an image forming operation after rotation of the photosensitive member is stopped in a state in which the image forming operation is not completed, the controller carries out control so that the second trailing end voltage is applied when a trailing end of the recording material with respect to a feeding direction passes through a transfer portion.

Image forming apparatus that selectively changes trailing end voltage

An image forming apparatus includes a photosensitive drum, a charging member, an exposure unit, a developing member, and a transfer member. In a rotational axis direction of the charging member, a width of a transfer portion of the transfer member is shorter than that of a charging portion of the charging member, and an end of the surface of the photosensitive drum in the axis direction includes a non-transfer area in contact with the charging member and not in contact with the transfer member. The exposure unit exposes the non-transfer area during rotation of the photosensitive drum, and forms a surface potential on the surface downstream of an exposing portion and upstream of the transfer portion with respect to a rotational direction. A controller controls such that an absolute value of the surface potential of the non-transfer area is lower than that of the transfer outside paper passing area.

An image forming apparatus includes an image forming unit configured to form a toner image on a recording material, a fixing unit configured to fix the toner image formed on the recording material by the image forming unit to the recording material, and a controller configured to cause the image forming unit to form an image on a basis of image information, the controller being configured to cause the image forming unit to form the image in which a first toner image and a second toner image is superimposed on each other on the recording material, the first toner image being a toner image corresponding to the image information, the second toner image being constituted by a pattern having anisotropy such that glossiness of the image changes depending on a direction in which the image is viewed.

A cylindrical fixing member for use with a fixing device includes a heat generating layer and an electrode layer contacting the heat generating layer. The electrode layer is smaller in volume resistance value than the heat generating layer. The electrode layer is formed in a helical shape so that a helical axis thereof extends in a direction along a generatrix direction of the fixing member. One end and the other end of the electrode layer are electrically open.

Cylindrical fixing member, fixing device and image forming apparatus

An image forming apparatus uses the difference in time taken for each patch to reach a color sensor, which occurs upon reversing the conveyance direction of a printing material. Due to this difference in time, the temperature of the printing material in detection by the color sensor differs among the respective patches. The error of a colorimetric value due to thermochromism is reduced by placing a patch with a colorimetric value which has a low temperature dependence so as to be detected earlier, and a patch with a colorimetric value which has a high temperature dependence so as to be detected later.

Color image forming apparatus having function of obtaining color information of patch

An image forming apparatus includes a diode for restraining deterioration of an electric discharge device caused when a voltage applied to a discharge electrode and a shield electrode is switched. By switching the voltage at only one position using the diode, both of the voltage applied to the discharge electrode and the voltage applied to the shield electrode can be switched simultaneously.

Image forming apparatus and electric discharge device

An image heating apparatus has a flexible rotatable member; a slidable member for sliding contact with an inner surface of the rotatable member; a back-up member for forming a nip with the slidable member with the rotatable member interposed therebetween, wherein a projection extended along a longitudinal direction of the rotatable member, and provided on such a portion of a sliding surface of the slidable member as is downstream of a center of the sliding surface with respect to a recording material feeding direction in which the recording material is fed, and wherein the projection is effective to provide a maximum pressure in a distribution, with respect to the recording material feeding direction, of pressure applied to the nip.

Image heating apparatus having recording medium conveying nip nonuniform in pressure distribution

An image forming apparatus includes a plurality of image bearing members for respectively bearing toner images, a moving member, a plurality of transfer devices for electrostatically transferring a toner image on each of the image bearing members onto the moving member or a transfer material borne by the moving member, a plurality of collecting devices for respectively collecting toner on each image bearing member, a selecting device for selecting an image bearing member to which toner on the moving member is to be transferred to the plural image bearing members.

Image forming apparatus with plural transfer means and selecting mechanism for selecting from among a plurality of image bearing members

When a cleaner is included exclusively for cleaning a transfer/transport belt to remove toner therefrom, the structure of an image forming apparatus becomes complex and the costs thereof increase. The present invention attempts to remedy this situation. Specifically, a difference between a peripheral speed relative to the transfer/transport belt to be set for cleaning and a peripheral speed relative to photosensitive drums to be set therefor is made larger than that between peripheral speeds to be set for ordinary image formation. Because of this constituent feature, unnecessary toner on the transfer/transport belt is efficiently transferred onto the photosensitive drums on a stable basis for a short period of time.

Growing community of inventors

Susono, Japan

Masatake Usui