In some embodiments of the present invention, quantized frequency coefficients of a matrix of spatial data are obtained. Accordingly, if a single solar cell device fails, there is an alternate path by which the output power of all other solar cell devices may contribute to the total output power of the solar cell array. When a system is rebooted or the system mode is changed in a state in which the display mode information is stored, display mode information stored being associated with a current system mode is read, and the LCD display mode is set to an arbitrary display mode corresponding to the read display mode information.