Patent ID: 8303073

Claim:
A liquid discharge apparatus which discharges a liquid, comprising: a liquid discharge head having a nozzle which is formed therein and through which the liquid is discharged, a pressure applying mechanism which applies a discharge pressure to discharge the liquid from the nozzle, and a first connecting terminal which is an input terminal of the pressure applying mechanism; a printed circuit board which has a second connecting terminal electrically connected to the first connecting terminal; a driver IC which is electrically connected to the printed circuit board and which supplies a signal for driving the pressure applying mechanism to the pressure applying mechanism via the printed circuit board; a discharge detecting mechanism which detects whether or not the liquid is discharged from the nozzle under a condition that the signal is supplied to the pressure applying mechanism; a connection inspecting mechanism which inspects electrical connection between the first connecting terminal and the second connecting terminal and which controls the driver IC to supply a connection inspecting signal to the pressure applying mechanism, the connection inspecting signal being set so that the liquid is discharged from the nozzle under a condition that the connection between the first connecting terminal and the second connecting terminal is normal connection, and that the liquid is not discharged from the nozzle under a condition that the connection between the first connecting terminal and the second connecting terminal is not the normal connection; and the connection inspecting mechanism controlling the discharge detecting mechanism to detect whether or not the liquid is discharged from the nozzle under a condition that the connection inspecting signal is supplied to the pressure applying mechanism; and a judging mechanism which performs judgment whether or not the connection between the first connecting terminal and the second connecting terminal corresponding to the nozzle is the normal connection based on a detection result of the discharge detecting mechanism; wherein the connection inspecting mechanism includes a timer which measures an elapsed time after the electrical connection between the first connecting terminal and the second connecting terminal has been inspected; and an elapsed time judging mechanism which judges whether or not the elapsed time exceeds a predetermined time; the connection inspecting mechanism controls the driver IC so that the connection inspecting signal is supplied to the pressure applying mechanism under a condition that the elapsed time judging mechanism judges that the elapsed time exceeds the predetermined time, and the connection inspecting mechanism controls the discharge detecting mechanism so that it is detected whether or not the liquid is discharged from the nozzle under a condition that the connection inspecting signal is supplied to the pressure applying mechanism.