Abstract: A fixing device, including a fixing member; an opposing member contacting the fixing member to form a fixing nip; plural separation assisting members; a contact direction biasing member contacting an end of the auxiliary separation members to the surface of the fixing member; a contact and release switching member switching contacting the end of the auxiliary separation members to the surface of the fixing member and releasing the end of the auxiliary separation members therefrom; a fixing exit guide member guiding a recording medium to a discharge direction and separated from the fixing member by the separation assisting member; a first rotating member near the auxiliary separation members downstream from an end thereof; and a second rotating member guiding a recording medium guided by the fixing exit guide member in the recording medium conveyance direction while rotating.

Abstract: An image forming apparatus enables a high-quality double-side printing of a transfer medium by one-pass method using a simple structure. A latent image is formed and developed on an image carrier (drum) in a process cartridge. A resultant toner image is transferred by a first transfer unit (roller) onto either an upper surface of the transfer medium or a first intermediate transfer body (roller) in a first transfer area. The toner image on the first intermediate transfer body is transferred onto a back surface of the transfer medium in a fourth transfer area via a second intermediate transfer body (belt) and a third intermediate transfer body (roller). The fourth transfer area is located downstream of the first transfer area along a transport path of the transfer medium.

Abstract: A development device includes a developer carrier configured to carry on a surface thereof a developer, the developer carrier being disposed to face a latent image carrier, a developer tank having the developer carrier, a developer container configured to house the developer to be supplied to the developer tank, the developer container being connected to the developer tank through a partition having an opening, and a developer carrier member configured to carry the developer in the developer container, the developer being supplied to the developer tank from the opening while being carried by the developer carrier member, and the amount of developer to be supplied to the developer tank from the opening being gradually increased in a developer carrying direction of the developer carrier member.

Abstract: A fixing device includes a fixing roller and a pressing roller that are in pressure contact with each other. A separating plate is placed opposite to the fixing roller with a certain gap in between them. Positioning portions are installed on the separating plate to be in contact with width-direction ends of the fixing roller for determining the gap. The positioning portions are arranged such that edges of contact portions of the positioning portions on the width-direction center side in contact with the fixing unit are positioned outside an image area and inside a paper-passing area for a recording medium of a maximum passing-capable size.

Abstract: An image forming apparatus, forming a color image by successively superposing color images, formed on image carriers of corresponding image forming parts arranged along a rotational direction of an endless moving member, onto the endless moving member or a recording medium conveyed thereby, includes a first part causing a color registration pattern to be created on the endless moving member or the recording medium; a second part obtaining a color registration pattern signal by detecting the color registration pattern; a third part changing image formation timing in the image forming parts based on the color registration pattern signal; and a fourth part causing the endless moving member to rotate in forward and reverse directions after the creation of the color registration pattern. The second part obtains the color registration pattern signal by detecting the color registration pattern during each of the forward and reverse rotations of the endless moving member.

Abstract: Toner is supplied from a toner container to a developing part that causes the toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, a pre-toner-supply operation of supplying a predetermined amount of toner to the developing part is carried out, a fog detecting image is formed and fog is detected in the fog detecting image, a toner supply amount to be supplied to the developing part is determined based on the fog detected in the detecting and an operational status of the developing part since the toner was supplied to the developing part the last time, and the toner supply amount of the toner determined in the determining is supplied to the developing part.

Abstract: A toner supplying method for supplying toner from a toner container to a developing part that causes toner to adhere to a latent image formed on a latent image carrying member and develops the latent image, includes detecting a toner amount in the developing part as being equal to or less than a predetermined toner amount value; forming a fog detecting image in a case where the toner amount in the developing part is equal to or less than the predetermined toner amount value, and detecting fog; and determining based on the detected fog whether to execute a toner ejecting process of ejecting the toner remaining in the developing part toward the latent image carrying member before supplying the toner to the developing part from the toner container.

Abstract: A developing unit includes: a developer carrier; a toner supplying member having a porous surface layer; a toner storage storing therein toner; a stirring member that is rotated to stir the toner; a toner amount detecting unit that detects an amount of the toner; a toner supplying unit that supplies new toner to the toner storage based on a detection result; and a toner removing member that removes the toner carried in the porous surface layer, wherein the toner removing member is arranged in a separable and contactable manner from and with the porous surface layer, and the developing unit has a stirring mode in which the toner removing member is brought into contact with the porous surface layer, and the toner supplying member is rotated while the stirring member is rotated to stir the toner.

Abstract: A fixing device includes a cylindrical fixing member, having an external circumferential surface including a crown portion curved radially outward and a inverted-crown portion curved radially inward, a pressing unit including a convexity and a concavity formed on a facing surface facing the fixing member, a first heating member to heat the fixing member, corresponding to the crown portion of the fixing member, a second heating member to heat the fixing member, corresponding to the inverted-crown portion of the fixing member, a temperature detector to detect a surface temperature of the fixing member, and a controller to control the first heating member and the second heating member independently. The pressing unit presses against the fixing member while the crown portion and the inverted-crown portion of the fixing member match the concavity and the convexity of the pressing unit, respectively, forming a curved fixing nip therebetween.

Abstract: A fixing device includes a fixing nip and a guide member to guide a recording medium transported through a recording media transport pathway to the fixing nip, disposed upstream from the fixing nip in a direction in which the recording medium is transported and facing an unfixed-image side of the recording media. The guide member includes a guide face, the guide face including a first guide face and a second guide face located where at least a trailing-edge of the recording medium approaches the guide member as the recording medium is transported through the recording media transport pathway and which is inclined with respect to the first guide face away from the recording media transport pathway, and a first spur rotatably provided on the guide member and projecting into the recording media transport pathway from a connection portion between the first guide face and the second guide face.

Abstract: An image forming apparatus, forming a color image by successively superposing color images, formed on image carriers of corresponding image forming parts arranged along a rotational direction of an endless moving member, onto the endless moving member or a recording medium conveyed thereby, includes a first part causing a color registration pattern to be created on the endless moving member or the recording medium; a second part obtaining a color registration pattern signal by detecting the color registration pattern; a third part changing image formation timing in the image forming parts based on the color registration pattern signal; and a fourth part causing the endless moving member to rotate in forward and reverse directions after the creation of the color registration pattern. The second part obtains the color registration pattern signal by detecting the color registration pattern during each of the forward and reverse rotations of the endless moving member.

Abstract: An image forming apparatus enables a high-quality double-side printing of a transfer medium by one-pass method using a simple structure. A latent image is formed and developed on an image carrier (drum) in a process cartridge. A resultant toner image is transferred by a first transfer unit (roller) onto either an upper surface of the transfer medium or a first intermediate transfer body (roller) in a first transfer area. The toner image on the first intermediate transfer body is transferred onto a back surface of the transfer medium in a fourth transfer area via a second intermediate transfer body (belt) and a third intermediate transfer body (roller). The fourth transfer area is located downstream of the first transfer area along a transport path of the transfer medium.

Abstract: A fixing device and an image forming apparatus using this, in which even if permanent warping is produced on a roller member that forms a fixing nip portion, no collision sound is produced due to the collision of gears, the fixing device including: two roller members that form a nip portion in which a recording medium is pressed by pressure means and transported; and a drive gear that engages with a shaft portion of one of the two roller members and transmits driving force to that roller member. A key is formed in the drive gear and a key groove having a gap opened therein is formed in the shaft portion, and when a rotation velocity of the roller member increases, transmission of driving force from the drive gear to the shaft portion is suspended and the drive gear slides on the shaft portion.

Abstract: A fixing device includes a fixing roller and a pressing roller that are in pressure contact with each other. A separating plate is placed opposite to the fixing roller with a certain gap in between them. Positioning portions are installed on the separating plate to be in contact with width-direction ends of the fixing roller for determining the gap. The positioning portions are arranged such that edges of contact portions of the positioning portions on the width-direction center side in contact with the fixing unit are positioned outside an image area and inside a paper-passing area for a recording medium of a maximum passing-capable size.