Abstract: Provided is a conductive roller in which the occurrence of an image defect caused by a pressure mark is suppressed. In this conductive roller, plural resin layers are arranged on the outer circumference of a shaft 4. The resin layers include at least a base layer 1 and a surface layer 3 from the inner circumferential side. The plural resin layers all have a loss tangent (tan ?) of 0.2 or less at a temperature of 40° C. and, among the plural resin layers, at least a pair of two adjacent layers satisfy a relationship of G?o?G?i between the elastic modulus G?o of a layer positioned on the outer circumferential side and the elastic modulus G?i of a layer positioned on the inner circumferential side.

Abstract: Provided is a urethane resin composition by which an electrically conductive roller which has a higher elasticity than ever and in which an air bubble in an elastic layer is fine can be obtained when the urethane resin composition is used for the elastic layer of the electrically conductive roller, and an electrically conductive roller using the same. The urethane resin composition comprises: a urethane resin having a carboxyl group on a side chain; a cross-linking agent having an epoxy group; and an ester composed of a sugar and an unbranched saturated fatty acid having 16 to 24 carbon atoms as a foaming agent. The saturated fatty acid is preferably a stearic acid. The urethane resin composition preferably further contains a foaming auxiliary. The sugar is preferably a sucrose.

Abstract: Provided is a urethane resin composition by which an electrically conductive roller which has a higher elasticity than ever and in which an air bubble in an elastic layer is fine can be obtained when the urethane resin composition is used for the elastic layer of the electrically conductive roller, and an electrically conductive roller using the same. The urethane resin composition comprises: a urethane resin having a carboxyl group on a side chain; a cross-linking agent having an epoxy group; and an ester composed of a sugar and an unbranched saturated fatty acid having 16 to 24 carbon atoms as a foaming agent. The saturated fatty acid is preferably a stearic acid. The urethane resin composition preferably further contains a foaming auxiliary. The sugar is preferably a sucrose.

Abstract: A control device which controls a servo motor of a machine tool in the event of power failure is provided.

Abstract: A control device which controls a servo motor of a machine tool in the event of power failure is provided.

Abstract: The present invention provides a position control apparatus in which a motor output torque can be approximated to that of the maximum output torque curve of the motor by generating a position command combining constant acceleration and exponential acceleration. This position control apparatus comprises means for generating a position command so as to give constant acceleration by adding an acceleration unit quantity &Dgr;Naa, set as a parameter beforehand, to a speed unit quantity N(n), means for generating a position command by calculating an acceleration unit quantity using an exponential function expression and by adding the calculated result to the speed unit quantity N(n), and means for generating a position command by comparing the present speed unit quantity N(n) and a function change speed unit quantity Nc set as a parameter beforehand and by selecting either of the command generating means described above on the basis of the compared result.