Abstract: An object of the present invention is to provide a porous material for polishing in which, during a polishing operation, it is possible to keep a proportion between abrasive grains in contact with an object to be polished and a resin portion in contact with the object to be polished within a certain range, even if an unskilled person attaches a polishing tool to an automated device and uses it, there is no need for complicated adjustment to stabilize the device, whereby it is possible to obtain precise surface accuracy. The above object is achieved by a porous material for polishing including an elastic foam having anisotropy, a polymer, and abrasive grains.

Abstract: A fixing device includes an endless belt member, a secured member disposed to contact the belt member, a heating unit that heats the belt member, and a rotary pressurizing roller including an elastic layer that is elastically deformed when the belt member is pressed against a pressing surface of the secured member to form a fixing part. The pressurizing roller is curved such that a center portion is smaller in outside diameter than end portions along the axial direction. The pressing surface is curved such that a center portion projects toward the pressurizing roller more than end portions along the longitudinal direction. On the pressing surface, an amount of projection of the center portion with respect to the end portions along the longitudinal direction is set to be larger on an output side than on an input side of the fixing part along a moving direction of the belt member.

Abstract: A fixing device includes a belt, a secured member, a support roller, a heating unit, and a pressure roller that is driven to rotate and has an elastic surface layer deformed when pressing the belt against the secured member so as to form a fixing portion. A recording medium that holds an unfixed image passes through the fixing portion. The secured member has a contact portion and an insertion portion having first and second curved surfaces respectively curved toward first and second sides opposite to each other. Conditions t(1/r1+1/r2)?0.130 and r1<r2 are satisfied where t denotes a thickness of the belt, r1 denotes a radius of curvature of the second curved surface in mm, and r2 denotes a radius of curvature of the first curved surface in mm.

Abstract: A fixing device includes: an endless belt member; a secured member disposed to contact the belt member; a support roller that rotatably supports the belt member; a heating unit that heats the belt member; and a rotary pressurizing roller that includes an elastic surface layer that is elastically deformed when the belt member is pressed against the secured member to form a fixing part. The secured member includes a recessed part provided on a surface of the secured member that faces the pressurizing roller and configured to curve the belt member into a recessed shape, projecting parts provided upstream and downstream of the recessed part, respectively, and configured to curve the belt member into a projected shape, and a region provided between at least one of the projecting parts and the recessed part and having a small curvature compared to the corresponding projecting part.

Abstract: A fixing device includes a rotatable endless belt, a heating source that heats the belt, a pad member having a sliding surface abutting on an inner surface of the belt, and a pressure roller that presses an outer surface of the belt toward the sliding surface and rotates to rotate the belt. The pressure roller works together with the belt to fix an unfixed toner image onto a medium that bears the unfixed toner image by allowing the medium to enter between the roller and the belt. Assuming that the sliding surface is divided into upstream and downstream regions in a moving direction of the belt, the upstream and downstream regions both have recessed curved surfaces in the moving direction. A first curved surface corresponding to the upstream region has an average curvature that is larger than that of a second curved surface corresponding to the downstream region.

Abstract: A fixing device includes a belt, a secured member, a support roller, a heating unit, and a pressure roller that is driven to rotate and has an elastic surface layer deformed when pressing the belt against the secured member so as to form a fixing portion. A recording medium that holds an unfixed image passes through the fixing portion. The secured member has a contact portion and an insertion portion having first and second curved surfaces respectively curved toward first and second sides opposite to each other. Conditions t(1/r1+1/r2)?0.130 and r1<r2 are satisfied where t denotes a thickness of the belt, r1 denotes a radius of curvature of the second curved surface in mm, and r2 denotes a radius of curvature of the first curved surface in mm.

Abstract: A fixing device includes: an endless belt member; a secured member disposed to contact the belt member; a support roller that rotatably supports the belt member; a heating unit that heats the belt member; and a rotary pressurizing roller that includes an elastic surface layer that is elastically deformed when the belt member is pressed against the secured member to form a fixing part. The secured member includes a recessed part provided on a surface of the secured member that faces the pressurizing roller and configured to curve the belt member into a recessed shape, projecting parts provided upstream and downstream of the recessed part, respectively, and configured to curve the belt member into a projected shape, and a region provided between at least one of the projecting parts and the recessed part and having a small curvature compared to the corresponding projecting part.

Abstract: A fixing device includes an endless belt member, a secured member disposed to contact the belt member, a heating unit that heats the belt member, and a rotary pressurizing roller including an elastic layer that is elastically deformed when the belt member is pressed against a pressing surface of the secured member to form a fixing part. The pressurizing roller is curved such that a center portion is smaller in outside diameter than end portions along the axial direction. The pressing surface is curved such that a center portion projects toward the pressurizing roller more than end portions along the longitudinal direction. On the pressing surface, an amount of projection of the center portion with respect to the end portions along the longitudinal direction is set to be larger on an output side than on an input side of the fixing part along a moving direction of the belt member.

Abstract: A fixing device includes a rotatable endless belt, a heating source that heats the belt, a pad member having a sliding surface abutting on an inner surface of the belt, and a pressure roller that presses an outer surface of the belt toward the sliding surface and rotates to rotate the belt. The pressure roller works together with the belt to fix an unfixed toner image onto a medium that bears the unfixed toner image by allowing the medium to enter between the roller and the belt. Assuming that the sliding surface is divided into upstream and downstream regions in a moving direction of the belt, the upstream and downstream regions both have recessed curved surfaces in the moving direction. A first curved surface corresponding to the upstream region has an average curvature that is larger than that of a second curved surface corresponding to the downstream region.