Element substrate, printhead and printing apparatus

A printhead comprising:

• an element substrate provided with a plurality of electrothermal transducers, a plurality of drive elements for driving each of the plurality of the electrothermal transducers, a logic circuit for supplying a signal to the plurality of the drive elements, and a temperature detection element, and connected to an external apparatus having a circuit for detecting a temperature based on a temperature detection signal outputted from the temperature detection element;
• and
• a plurality of nozzles corresponding to the plurality of the electrothermal transducers, wherein
• the element substrate includes:
• a first wiring grounded, connected to an end portion of the temperature detection element, and serving as a reference voltage of a temperature detection signal outputted from the temperature detection element;
• a second wiring connected to the first wiring in the vicinity of the temperature detection element;
• a first pad connected to the first wiring;
• and
• a second pad connected to the second wiring, wherein
• in a case where the element substrate is connected to the external apparatus, a wiring, serving as a reference voltage for a side on which the temperature detection signal of the circuit that the external apparatus has is inputted is connected to the second pad via the first pad connected to a ground serving as a reference voltage of the external apparatus, and wherein
• ink is bubbled by thermal energy generated by driving the plurality of electrothermal transducers and printing is performed by the ink being discharged from the plurality of nozzles.

A printing apparatus for performing printing by discharging ink onto a print medium by using a printhead, wherein the printhead comprises:

• an element substrate provided with a plurality of electrothermal transducers, a plurality of drive elements for driving each of the plurality of the electrothermal transducers, a logic circuit for supplying a signal to the plurality of the drive elements, and a temperature detection element, and connected to an external apparatus having a circuit for detecting a temperature based on a temperature detection signal outputted from the temperature detection element;
• and
• a plurality of nozzles corresponding to the plurality of the electrothermal transducers, wherein
• the element substrate includes:
• a first wiring grounded, connected to an end portion of the temperature detection element, and serving as a reference voltage of a temperature detection signal outputted from the temperature detection element;
• a second wiring connected to the first wiring in the vicinity of the temperature detection element;
• a first pad connected to the first wiring;
• and
• a second pad connected to the second wiring, wherein
• in a case where the element substrate is connected to the external apparatus, a wiring, serving as a reference voltage for a side on which the temperature detection signal of the circuit that the external apparatus has is inputted is connected to the second pad via the first pad connected to a ground serving as a reference voltage of the external apparatus, and wherein
• ink is bubbled by thermal energy generated by driving the plurality of electrothermal transducers and printing is performed by the ink being discharged from the plurality of nozzles,
• the printing apparatus comprising:
• an amplifier configured to amplify a temperature detection signal outputted from the temperature detection element;
• an A/D converter configured to perform analog-to-digital conversion of the temperature detection signal amplified by the amplifier;
• a third wiring serving as a reference voltage of an analog part of the amplifier and the A/D converter;
• a fourth wiring that is grounded;
• a fifth pad connected to the third wiring;
• and
• a sixth pad connected to the fourth wiring, wherein
• in a case where the printhead is connected, the fifth pad is connected to the second pad, the sixth pad is connected to the first pad, and a circuit is formed from the third wiring through the fifth pad and the second pad, through the second wiring and the first wiring, through the first pad and the sixth pad, and to the fourth wiring.