Patent ID: 7345501

Claim:
An electro-optical device comprising: a first substrate; a first IC that has a plurality of first terminals and that is mounted on the first substrate; a plurality of second terminals that are formed on the first substrate to be connected to the first terminals; a plurality of wiring lines formed on the first substrate; a pair of first connection state diagnostic terminals that is included in the first terminals of the first IC and that is used for diagnosing connection state between the first terminals and the second terminals; a pair of second connection state diagnostic terminals that is included in the second terminals on the first substrate and that is connected to the air of first connection state diagnostic terminals, the pair of second connection state diagnostic terminals being electrically connected together by one of the wiring lines; a connection state diagnostic unit that is provided in the first IC and that outputs a signal to one of the first pair of first connection state diagnostic terminals, and receives input of the signal from the other of the pair of first connection state diagnostic terminals that was transmitted through the pair of second connection state diagnostic terminals and the one of the wiring lines to diagnose whether the pair of first connection state diagnostic terminals are electrically connected to the pair of second connection state diagnostic terminals; and a connection state diagnosis result output unit that is provided in the first IC and that outputs a diagnosis result diagnosed by the connection state diagnostic unit.