Abstract: A polyurethane dispersion is an aqueous dispersion of a polyurethane resin. The polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer and a chain extender. The isocyanate group-terminated prepolymer includes a reaction product of a polyisocyanate component containing a xylylene diisocyanate, and an active hydrogen group-containing component containing a short-chain diol having 2 to 6 carbon atoms and an active hydrogen group-containing compound containing a hydrophilic group. The chain extender includes an ethylenediamine. A ratio of the ethylenediamine is 25 mol % or more with respect to the total amount of the chain extender.

Abstract: The problem to be solved by the present invention is to provide a light diffuser plate and a process for production thereof, which light diffuser plate can diffuse light selectively in any desired direction even when the number of cold cathode fluorescent lamps as backlights is reduced and the gap between cold cathode fluorescent lamps is increased, so suppressing luminance unevenness and lamp image with good repeatability in stable way and maintaining high luminance. The present invention is also aimed at providing a backlight unit that possesses similar characteristics.

Abstract: An image forming apparatus includes an image forming mechanism and an image bearing member. The image forming mechanism is configured to form an image. The image bearing mechanism is detachably provided to the image forming apparatus. The image bearing mechanism includes an image bearing member configured to bear the image formed by the image forming mechanism, and a through shaft configured to support the image bearing member.

Abstract: An image forming apparatus whereby it is possible to prevent unevenness in developing density caused by misalignment between the central axes of a driven side rotational coupling section for rotating a developer carrier and a drive side rotational coupling section for transmitting rotational drive force to the driven side rotational coupling section. The driven side rotational coupling section is fixed and the position thereof can be corrected slightly, by engaging the driven side rotational coupling section with a drive side rotational coupling section. A transmission gear is provided which meshes with the driven side rotational coupling section and transmits rotational drive force used to move the surface of the developer carrier. By means of an axle provided on at least one end of the transmission gear engaging with a positioning member on the main body of the image forming apparatus, the developer carrier is positioned in the main body of the image forming apparatus.

Abstract: An image forming apparatus includes an image forming mechanism and an image bearing member. The image forming mechanism is configured to form an image. The image bearing mechanism is detachably provided to the image forming apparatus. The image bearing mechanism includes an image bearing member configured to bear the image formed by the image forming mechanism, and a through shaft configured to support the image bearing member.

Abstract: A developing device includes a developer carrier and a developer regulating member including a developer regulating part opposing a surface of the developer carrier to regulate the developer carried and conveyed by the developer carrier. The developer regulating member is formed from a single metallic member and includes a space that faces an inner surface of the metallic member. The space extends in a direction perpendicular to a moving direction of the surface of the developer carrier. The developing device can include a cooling device that cools the developer regulating member from an inner surface side of the metallic member facing the space.

Abstract: A developing device of the present invention includes a developing roller including a sleeve and a magnet roller accommodated in the sleeve. The surface of the sleeve s configured such that the center portion, including an image forming range corresponding to the image forming range of an image carrier, in the direction of width perpendicular to the direction of movement of the above has a higher developer conveying ability than opposite end portions outward of the center portion. Opposite ends of the magnetic pole of the magnet roller in the direction of width face the opposite end portions of the sleeve.

Abstract: An image forming apparatus whereby it is possible to prevent unevenness in developing density caused by misalignment between the central axes of a driven side rotational coupling section for rotating a developer carrier and a drive side rotational coupling section for transmitting rotational drive force to the driven side rotational coupling section. The driven side rotational coupling section is fixed and the position thereof can be corrected slightly, by engaging the driven side rotational coupling section with a drive side rotational coupling section. A transmission gear is provided which meshes with the driven side rotational coupling section and transmits rotational drive force used to move the surface of the developer carrier. By means of an axle provided on at least one end of the transmission gear engaging with a positioning member on the main body of the image forming apparatus, the developer carrier is positioned in the main body of the image forming apparatus.

Abstract: An image forming apparatus includes an image forming mechanism and an image bearing member. The image forming mechanism is configured to form an image. The image bearing mechanism is detachably provided to the image forming apparatus. The image bearing mechanism includes an image bearing member configured to bear the image formed by the image forming mechanism, and a through shaft configured to support the image bearing member.

Abstract: A developing device and method that develops a latent image with a two-component developer includes a developer carrier, a first developer conveying screw that conveys the developer from a first to a second end of the first developer conveying screw and transfers the developer to the developer carrier, and a second developer conveying screw that conveys the developer from a first to a second end of the second developer conveying screw and conveys the developer from the second end of the second developer conveying screw to the first end of the first developer conveying screw. A following relationship is satisfied: T2≧3T1, where T1 is a time for conveying the developer from the first to the second end of the second developer conveying screw, and T2 is a time for conveying the developer from the first to the second end of the first developer conveying screw.

Abstract: A developing device includes a developer carrier and a developer regulating member including a developer regulating part opposing a surface of the developer carrier to regulate the developer carried and conveyed by the developer carrier. The developer regulating member is formed from a single metallic member and includes a space that faces an inner surface of the metallic member. The space extends in a direction perpendicular to a moving direction of the surface of the developer carrier. The developing device can include a cooling device that cools the developer regulating member from an inner surface side of the metallic member facing the space.

Abstract: A developing device for an image forming apparatus of the present invention includes a developing roller made up of a sleeve and a magnet roller and a doctor facing the surface of the sleeve. The edge of the doctor faces the sleeve at a particular position selected to stabilize the amount of a developer to be scooped up, protect the developer from deterioration, and allow an adequate amount of charge to deposit on the developer by friction.

Abstract: A developing device of the present invention includes a developing roller including a sleeve and a magnet roller accommodated in the sleeve. The surface of the sleeve s configured such that the center portion, including an image forming range corresponding to the image forming range of an image carrier, in the direction of width perpendicular to the direction of movement of the above has a higher developer conveying ability than opposite end portions outward of the center portion. Opposite ends of the magnetic pole of the magnet roller in the direction of width face the opposite end portions of the sleeve.

Abstract: A developing device that develops a latent image with a two-component developer includes a developer carrier, a first developer conveying screw that conveys the developer from a first to a second end of the first developer conveying screw and transfers the developer to the developer carrier, and a second developer conveying screw that conveys the developer from a first to a second end of the second developer conveying screw and conveys the developer from the second end of the second developer conveying screw to the first end of the first developer conveying screw.

Abstract: An image forming apparatus includes a development mechanism using a two-component development agent and which includes a development roller and first and second transfer screws. The first transfer screw, arranged at a position approximately horizontal and in parallel to the development roller, includes a first number of screw spirals for transferring the development agent from a first end to a second end of the first transfer screw and conveying the development agent to the development roller. The second transfer screw, arranged approximately horizontal and in parallel to the first transfer screw, includes a second number of screw spirals for transferring the development agent from a first end to a second end of the second transfer screw and conveying the development agent from the second end of the second transfer screw to the first end of the first transfer screw. The first and second numbers of the screw spirals are different from each other.

Abstract: A developing device for an image forming apparatus of the present invention includes a developing roller made up of a sleeve and a magnet roller and a doctor facing the surface of the sleeve. The edge of the doctor faces the sleeve at a particular position selected to stabilize the amount of a developer to be scooped up, protect the developer from deterioration, and allow an adequate amount of charge to deposit on the developer by friction.

Abstract: A developer container for use in an image forming apparatus including a supporting member rotating around a rotation shaft thereof. A plurality of developing devices are arranged on the supporting member, each developing device including a developer supplying device. A plurality of cylindrically-shaped developer containers containing developer are provided, each developer container having an opening and a guide, and each developer container being detachably mounted on the developer supplying device. A container rotating device rotates the developer container, in which the guide is arranged that when one of the developing devices needs to be filled with the developer, the container rotating device rotates the developer container to transfer the developer in the developer container to the opening in accordance with a rotating movement of the developer container.

Abstract: An image forming apparatus includes a development mechanism using a two-component development agent and which includes a development roller and first and second transfer screws. The first transfer screw, arranged at a position approximately horizontal and in parallel to the development roller, includes a first number of screw spirals for transferring the development agent from a first end to a second end of the first transfer screw and conveying the development agent to the development roller. The second transfer screw, arranged approximately horizontal and in parallel to the first transfer screw, includes a second number of screw spirals for transferring the development agent from a first end to a second end of the second transfer screw and conveying the development agent from the second end of the second transfer screw to the first end of the first transfer screw. The first and second numbers of the screw spirals are different from each other.

Abstract: An image forming apparatus of the present invention includes a revolver type developing unit rotatably mounted on an apparatus body and having a plurality of developing sections, and an intermediate image transfer body having an endless movable surface to which a toner image is transferred from an image carrier. While the intermediate image transfer body is caused to run idle, the apparatus allows a minimum of toner apt to contaminate the background of a recording medium to be transferred from the developing section located at a developing position to the image carrier. Particularly, the apparatus frees the recording medium from contamination in the form of a band extending in the widthwise direction of the medium.

Abstract: An image forming apparatus including a development unit rotatably supported by a body of the apparatus and including a plurality of developing subunits and a plurality of replaceable developer containers each storing a developer to be replenished to a particular one of the developing subunits. Also included is a stepping motor configured to cause the developing unit to rotate in order to bring any one of the developing subunits to a developing position, a preventing mechanism configured to prevent the developing unit from rotating at a time of replacement of any one of the developer containers due to an unexpected change in a voltage or a current driving the stepping motor, and a locking portion included in either one of the developing unit and the body and an engaging portion included in the other of the developing unit and the body, in which the locking portion and the engaging portion selectively engaging with each other for preventing the developing unit from rotating.