Abstract: A development roller includes a core shaft, an elastic layer coating the core shaft, and a surface layer coating the elastic layer. The surface layer has a resistance smaller than a resistance of the elastic layer. And, the development roller has an entire volume resistance smaller than a volume resistance of the elastic layer.

Abstract: A mobile communication terminal and an operation control system of mobile communication terminals, in which its operation setting is changed suitably, are provided. The mobile communication terminal provides a GPS receiver and measures the exact position of its own terminal by receiving signals from GPS satellites. And the mobile communication terminal registers plural operation settings corresponding to addresses, and also a management center registers plural operation settings corresponding to addresses. When the mobile communication terminal moves from a first address to a second address, the mobile communication terminal measures its own position and transmits the measure position to a management center via a base station. The management center transmits the information of the second address and its operation setting to the mobile communication terminal via the base station, when the mobile communication terminal does not have the operation setting in its own terminal.

Abstract: A development roller for developing a latent electrostatic image to a visible toner image with toner, including a surface layer which contains a guanamine-skeleton-containing compound.