The image reader reads photoelectrically an original image including a visible image and an invisible image. The opposing member insertion section has a ring-shaped tongue piece andor a ring-shaped ring supporting section. The prisms are arranged side by side on one surface of the transparent substrate. The diagnostic unit is suitable for receiving authorization data from the vehicle key, for the indirect or direct wireless communication with the motor vehicle, and for proving its authorization with respect to the motor vehicle by way of the received authorization data.