US Patent 7882514 Display device on/off detection methods and apparatus

Display device ON/OFF detection methods and apparatus are disclosed. An example method disclosed herein to determine whether a presentation device is ON or OFF comprises determining a plurality of metrics based on monitoring at least one output of the presentation device, wherein each metric in the plurality of metrics comprises a decision indicating an operating state of the presentation device, and combining the plurality of metrics to determine whether the presentation device is one of ON or OFF, wherein combining the plurality of metrics comprises at least one of weighting the plurality of metrics or determining a majority vote of the plurality of metrics.