Patent ID: 7841678

Claim:
An element substrate for a printhead, which is detachable from a printing apparatus and includes a plurality of printing elements, a voltage application terminal for applying a driving voltage to drive the printing elements, and a logical circuit which is driven at a voltage lower than the driving voltage to control the printing elements, comprising: a signal input terminal which inputs a logical signal to be given to the logical circuit; and a connection status output circuit which outputs a signal reflecting an electrical connection status between the printhead and the printing apparatus on the basis of the voltage applied from the voltage application terminal, said connection status output circuit comprising voltage division means for dividing the voltage applied from the voltage application terminal, a first inverter which inverts the voltage divided by said voltage division means when the voltage exceeds a threshold, a second inverter which inverts an output signal from said first inverter, and a first AND circuit which outputs a result of a logical product of signals including the logical signal, wherein said connection status output circuit outputs the signal reflecting the electrical connection status between the printhead and the printing apparatus on the basis of the voltage divided by said voltage division means and the logical signal.