Abstract: A belt device includes a belt wound around a plurality of rollers, one of the plurality of rollers, and a belt contact member disposed on the one of the plurality of rollers. The belt rotates along with the plurality of rollers. The belt contact member faces an edge of the belt in an axial direction of the one of the plurality of rollers and includes a flat portion and a separation portion. The flat portion forms a plane perpendicular to the axial direction of the one of the plurality of rollers. The separation portion is disposed outboard of the flat portion in a radial direction of the one of the plurality of rollers and has a surface located farther from the edge of the belt than the flat portion in the axial direction of the one of the plurality of rollers.

Abstract: A belt control device includes a plurality of rollers, a belt wound around the plurality of rollers and configured to rotate along with the plurality of rollers, a belt contact member that the belt contacts when the belt moves in an axial direction of the plurality of rollers, and a shaft displacement member movable in the axial direction and including an inclined face inclined with respect to a surface of the belt to control movement of the belt in the axial direction. The belt, the belt contact member, and the shaft displacement member are configured to make a frictional force between an edge of the belt and the belt contact member greater than a frictional force between the belt contact member and the shaft displacement member.

Abstract: A belt device includes a belt wound around a plurality of rollers, one of the plurality of rollers, and a belt contact member disposed on the one of the plurality of rollers. The belt rotates along with the plurality of rollers. The belt contact member faces an edge of the belt in an axial direction of the one of the plurality of rollers and includes a flat portion and a separation portion. The flat portion forms a plane perpendicular to the axial direction of the one of the plurality of rollers. The separation portion is disposed outboard of the flat portion in a radial direction of the one of the plurality of rollers and has a surface located farther from the edge of the belt than the flat portion in the axial direction of the one of the plurality of rollers.

Abstract: A belt control device includes a plurality of rollers, a belt wound around the plurality of rollers and configured to rotate along with the plurality of rollers, a belt contact member that the belt contacts when the belt moves in an axial direction of the plurality of rollers, and a shaft displacement member movable in the axial direction and including an inclined face inclined with respect to a surface of the belt to control movement of the belt in the axial direction. The belt, the belt contact member, and the shaft displacement member are configured to make a frictional force between an edge of the belt and the belt contact member greater than a frictional force between the belt contact member and the shaft displacement member.

Abstract: A disclosed to-be-transferred object length measurement device includes a first rotating body; a passage detection unit detecting a passage of the to-be-transferred object; a rotation amount measurement unit measuring a rotation amount of the first rotating body in a first measurement period; a second rotating body feeding the to-be-transferred object; a speed detection unit detecting a first feeding speed and a second feeding speed of the to-be-transferred object; and a calculation unit calculating a feeding distance of the to-be-transferred object per a predetermined rotation amount of the first rotating body based on the first feeding speed, and further calculating a length of the to-be-transferred object based on the rotation amount of the first rotating body in the first measurement period, the feeding distance, and the second feeding speed of the to-be-transferred object in the second measurement period.

Abstract: A secondary transfer facing roller includes a roller part that has a through-hole penetrating in a rotary shaft line direction at a rotation center position, and a penetrating shaft member penetrating the through-hole of the roller part and spinning the roller part on a surface of the penetrating shaft member. Eccentric cams are fixed to both end regions that are not located in the roller part, so as to rotate integrally with the penetrating shaft member. A position regulating cam and an abutting roller form a gap between the intermediate transfer belt and the secondary transfer roller immediately before a transfer sheet enters a transfer nip part. While the gap is formed, current flows between the intermediate transfer belt and the secondary transfer roller via the position regulating cam and the abutting roller.

Abstract: A secondary transfer facing roller includes a roller part that has a through-hole penetrating in a rotary shaft line direction at a rotation center position, and a penetrating shaft member penetrating the through-hole of the roller part and spinning the roller part on a surface of the penetrating shaft member. Eccentric cams are fixed to both end regions that are not located in the roller part, so as to rotate integrally with the penetrating shaft member. A position regulating cam and an abutting roller form a gap between the intermediate transfer belt and the secondary transfer roller immediately before a transfer sheet enters a transfer nip part. While the gap is formed, current flows between the intermediate transfer belt and the secondary transfer roller via the position regulating cam and the abutting roller.

Abstract: A secondary transfer facing roller includes a roller part that has a through-hole penetrating in a rotary shaft line direction at a rotation center position, and a penetrating shaft member penetrating the through-hole of the roller part and spinning the roller part on a surface of the penetrating shaft member. Eccentric cams are fixed to both end regions that are not located in the roller part, so as to rotate integrally with the penetrating shaft member. A position regulating cam and an abutting roller form a gap between the intermediate transfer belt and the secondary transfer roller immediately before a transfer sheet enters a transfer nip part. While the gap is formed, current flows between the intermediate transfer belt and the secondary transfer roller via the position regulating cam and the abutting roller.

Abstract: A disclosed to-be-transferred object length measurement device includes a first rotating body; a passage detection unit detecting a passage of the to-be-transferred object; a rotation amount measurement unit measuring a rotation amount of the first rotating body in a first measurement period; a second rotating body feeding the to-be-transferred object; a speed detection unit detecting a first feeding speed and a second feeding speed of the to-be-transferred object; and a calculation unit calculating a feeding distance of the to-be-transferred object per a predetermined rotation amount of the first rotating body based on the first feeding speed, and further calculating a length of the to-be-transferred object based on the rotation amount of the first rotating body in the first measurement period, the feeding distance, and the second feeding speed of the to-be-transferred object in the second measurement period.

Abstract: A cleaning device includes a first cleaning portion provided at a position where a belt transfer body is moved after transfer, and includes a second cleaning portion having a cleaning member which contacts the belt transfer body, which is located at an end of the belt transfer body in the perpendicular direction to the moving direction of the belt transfer body. There is a fixing member for pressing the belt transfer body to the cleaning member. The fixing member is located at a position opposing the cleaning member with the belt transfer body therebetween.

Abstract: A secondary transfer facing roller includes a roller part that has a through-hole penetrating in a rotary shaft line direction at a rotation center position, and a penetrating shaft member penetrating the through-hole of the roller part and spinning the roller part on a surface of the penetrating shaft member. Eccentric cams are fixed to both end regions that are not located in the roller part, so as to rotate integrally with the penetrating shaft member. A position regulating cam and an abutting roller form a gap between the intermediate transfer belt and the secondary transfer roller immediately before a transfer sheet enters a transfer nip part. While the gap is formed, current flows between the intermediate transfer belt and the secondary transfer roller via the position regulating cam and the abutting roller.

Abstract: An optical encoder includes a light emitting unit that emits parallel light onto a plurality of marks that are arranged on an object such as a rotor or a belt, at a predetermined interval in a moving direction of the object, and a light receiving unit that receives light modulated by the marks. The parallel light is generated by a collimating lens.

Abstract: A mark detector optically detecting a scale having multiple marks formed successively at predetermined intervals along the moving direction of an endless belt member, and outputting an electrical signal corresponding to the presence or absence of the marks when the endless belt member moves is disclosed. The mark detector includes a light illumination part configured to illuminate the light illumination surface of the endless belt member on which surface the scale is formed with parallel light rays; a light receiving part configured to receive reflected light from the light illumination surface; and a variation prevention part configured to prevent a variation of the light illumination surface. The variation prevention part includes a holding member configured to hold the endless belt member in the vicinity of the light illumination surface movably in the moving direction from the exterior surface side and the interior surface side of the endless belt member.

Abstract: A transfer device transfers a visual image from an image carrier to a recording medium. The transfer device includes a first transfer element that moves and receives the visual image from the image carrier on a first surface of the first transfer element, a second transfer element provided opposite to the first surface of the first transfer element to pinch and convey the recording medium through a secondary transfer nip part, a facing roller provided on a second surface of the first transfer element opposite to the first surface thereof, and a constant-current power supply that applies an electric current voltage to a core metal of the facing roller to transfer the visual image from the first transfer element to the recording medium. The electric current voltage applied to the core metal has a polarity equal to a polarity of the visual image and is subjected to a constant-current control.

Abstract: A cleaning device includes a first cleaning portion provided at a position where a belt transfer body is moved after transfer, and includes a second cleaning portion having a cleaning member which contacts the belt transfer body, which is located at an end of the belt transfer body in the perpendicular direction to the moving direction of the belt transfer body. There is a fixing member for pressing the belt transfer body to the cleaning member. The fixing member is located at a position opposing the cleaning member with the belt transfer body therebetween.

Abstract: A scale is provided on a back side edge of an intermediate transfer belt for detecting an amount of movement of the belt. In a tandem type image forming apparatus, a sensor is provided as a scale-reading unit that reads the scale. Materials used for the intermediate transfer belt and the scale satisfy a relation that the Young's modulus of the intermediate transfer belt is greater than the Young's modulus of the scale.

Abstract: A method of transferring a plurality of toner images formed on a plurality of image carriers of different colors onto a sheet-type recording medium includes forming a mark image for adjusting a transfer position on each of the image carriers as a toner image; transferring the mark images to a common transfer medium; detecting optically a mutual positional relationship between the mark images; and controlling linear velocities of the image carriers based on a result of detecting the mutual positional relationship between the mark images, to transfer the toner images onto the sheet-type recording medium with a reduced misalignment between the toner images.

Abstract: A method of transferring a plurality of toner images formed on a plurality of image carriers of different colors onto a sheet-type recording medium includes forming a mark image for adjusting a transfer position on each of the image carriers as a toner image; transferring the mark images to a common transfer medium; detecting optically a mutual positional relationship between the mark images; and controlling linear velocities of the image carriers based on a result of detecting the mutual positional relationship between the mark images, to transfer the toner images onto the sheet-type recording medium with a reduced misalignment between the toner images.

Abstract: A transfer device transfers a visual image from an image carrier to a recording medium. The transfer device includes a first transfer element that moves and receives the visual image from the image carrier on a first surface of the first transfer element, a second transfer element provided opposite to the first surface of the first transfer element to pinch and convey the recording medium through a secondary transfer nip part, a facing roller provided on a second surface of the first transfer element opposite to the first surface thereof, and a constant-current power supply that applies an electric current voltage to a core metal of the facing roller to transfer the visual image from the first transfer element to the recording medium. The electric current voltage applied to the core metal has a polarity equal to a polarity of the visual image and is subjected to a constant-current control.

Abstract: A mark detector optically detecting a scale having multiple marks formed successively at predetermined intervals along the moving direction of an endless belt member, and outputting an electrical signal corresponding to the presence or absence of the marks when the endless belt member moves is disclosed. The mark detector includes a light illumination part configured to illuminate the light illumination surface of the endless belt member on which surface the scale is formed with parallel light rays; a light receiving part configured to receive reflected light from the light illumination surface; and a variation prevention part configured to prevent a variation of the light illumination surface. The variation prevention part includes a holding member configured to hold the endless belt member in the vicinity of the light illumination surface movably in the moving direction from the exterior surface side and the interior surface side of the endless belt member.