A sheet conveying device includes a drive roller having a shaft, a driven roller having a shaft, a biasing member that rotatably supports one of the drive roller and the driven roller and biases one of the drive roller and the driven roller against the other one of the drive roller and the driven roller, and a holding member that pivotally holds the biasing member. The invention particularly concerns a termination structure for such devices having trenched electrodes in the active area. A locking mechanism may prohibit access to the tray when locking the lid in a closed position. The cost of service data derived by the mobile unit is then sent back to the service provider. In digital cases, a 6 MHz digital channel may carry several digital advertisement channels. The method further includes a step for defining a non-active region on the substrate material.