Printhead board, printhead, and printing apparatus

A printhead mountable on a printing apparatus, the printhead comprising:

• a board;
• and
• a tank configured to store a liquid to be discharged by a printing element of said board,
• wherein said board comprises:
• a first terminal, second terminal, and a third terminal, which are used for connection to the printing apparatus;
• said printing element configured to discharge the liquid;
• a driving circuit connected to said first terminal;
• an inspection circuit having an input node connected to said first terminal and an output node connected to said second terminal;
• and
• a resistance element having a first node connected to said third terminal and a second node connected to an electrical path between the output node of said inspection circuit and said second terminal,
• wherein when an inspection signal for inspecting a connection state between the printing apparatus and the printhead is supplied from the printing apparatus to said first terminal, said inspection circuit outputs and output signal according to the inspection signal from said second terminal, and
• when a control signal for performing printing is supplied from the printing apparatus to said first terminal, said driving circuit drives said printing element according to the control signal, and said inspection circuit sets said inspection circuit and said second terminal in an open state with each other.

A printhead mountable on a printing apparatus, the printhead comprising:

• a board;
• and
• a holding structure configured to exchangeably hold a tank for storing a liquid to be discharged by aprinting element of said board,
• wherein said board comprises:
• a first terminal, a second terminal, and a third terminal, which are used for connection to the printing apparatus;
• a printing element configured to discharge the liquid;
• a driving circuit connected to said first terminal;
• an inspection circuit having an input node connected to said first terminal and an output node connected to said second terminal;
• and
• a resistance element having a first node connected to said third terminal and a second node connected to an electrical path between the output node of said inspection circuit and said second terminal,
• wherein when an inspection signal for inspecting a connection state between the printing apparatus and the printhead is supplied from the printing apparatus to said first terminal, said inspection circuit outputs signal according to the inspection signal from said second terminal, and
• when a control signal for performing printing is supplied from the printing apparatus to said first terminal, said driving circuit drives said printing element according to the control signal, and said inspection circuit sets said inspection circuit and said second terminal in an open state with each other.

A printing apparatus on which a printhead is mountable, comprising:

• a first terminal, a second terminal, and a third terminal, which are used for connection to the printhead;
• a determination unit for determining a connection state between the printing apparatus and the printhead based on a voltage of said second terminal when an inspection signal is output from said first terminal;
• a print control unit for outputting, from said first terminal, a control signal for driving the printhead to discharge a liquid;
• and
• a measurement unit for measuring a resistance value between said second terminal and said third terminal.