US Patent 7639223 Liquid crystal display apparatus detecting a freeze state

A liquid crystal display apparatus includes a liquid crystal panel, a driver configured to drive the liquid crystal panel, a control circuit configured to control the driver in response to a display data signal and control signal supplied from an exterior, and a check circuit configured to detect a change between frames in a detection-purpose signal that is included in at least one of the display data signal and control signal so as to output a check signal responsive to presence/absence of the change.