Image signal line driving circuits each include a timing controller that generates a control signal to control the image signal line driving circuit itself and a different image signal line driving circuit. A master belonging to the image signal line driving circuits has a function of applying the control signal to a slave belonging to the image signal line driving circuits. The image signal line driving circuits each include an abnormality detecting circuit that detects an operation abnormality in the image signal line driving circuit itself, and a master/slave switching circuit that sets the image signal line driving circuit itself as the master or slave image signal line driving circuit. When detecting an abnormality, the abnormality detecting circuit outputs a master/slave switching signal, thereby switching the slave image signal line driving circuit to the master and switching the master image signal line driving circuit to the slave.