Temperature measurement device

An apparatus, comprising:

• a substrate;
• a resistive element disposed onto a first region of the substrate and formed of a first material having a first temperature coefficient of resistivity;
• and
• a pair of traces coupled to the resistive element and each formed of a first plurality of sections of a second material having a second temperature coefficient of resistivity and a second plurality of sections of a third material having a third temperature coefficient of resistivity.

A method of measuring temperature of a substrate in a printhead, comprising:

• applying a substantially constant current to a series connection of a resistive element attached to a region of the substrate and formed of a first material having a first temperature coefficient of resistivity and a pair of traces attached to the substrate and formed of a second material having a second temperature coefficient of resistivity with the first material selected so that the first temperature coefficient of resistivity exceeds the second temperature coefficient of resistivity;
• applying a plurality of signals to a plurality of firing resistors included in the printhead;
• changing a resistance of the resistive element and changing a resistance of the pair of traces in response to heating of the resistive element resulting from the applying of the plurality of signals to the plurality of firing resistors;
• and
• measuring a voltage across the series connection of the resistive element and the pair of traces.

An imaging device, comprising

• an interface arranged to receive data from a computer;
• a processing device configured to generate image data using the data received from the interface;
• an imaging mechanism including a printhead having a substrate and configured to form an image on media corresponding to the image data by ejecting ink from the printhead;
• a memory to store the data and the image data;
• a resistive element attached to the substrate and formed of a first material having a first temperature coefficient of resistivity;
• a pair of traces coupled to the resistive element, attached to the substrate, and formed of a second material having a second temperature coefficient of resistivity with the first material selected so that the first temperature coefficient of resistivity exceeds the second temperature coefficient of resistivity;
• a power source configured to supply electrical power to the resistive element through the pair of traces;
• and
• a measurement device coupled to the pair of traces and configured to provide an output related to a resistance of the resistive element.

An inkjet printer, comprising

• an interface arranged to receive data from a computer;
• a processing device configured to generate image data using the data received from the interface;
• an imaging mechanism including a printhead having a substrate and configured to form an image on media corresponding to the image data by ejecting ink from the printhead;
• a memory to store the data and the image data;
• a resistive element disposed onto the substrate and formed of a first material having a first temperature coefficient of resistivity;
• and
• a pair of traces coupled to the resistive element and each formed of a first plurality of sections of a second material having a second temperature coefficient of resistivity and a second plurality of sections of a third material having a third temperature coefficient of resistivity;
• a power source configured to supply electrical power to the resistive element through the pair of traces;
• and
• a measurement device coupled to the pair of traces and configured to provide an output related to a resistance of the resistive element.

A temperature measurement system, comprising:

• a substrate;
• a resistive element attached to the substrate and formed of a material having a temperature coefficient of resistivity;
• and
• a pair of traces coupled to the resistive element, attached to the substrate, and including means for generating a first temperature induced resistance change in the pair of traces less than a second temperature induced resistance change in the resistive element, with the resistive element and the pair of traces subjected to a substantially equal temperature change;
• means for generating an output related to a temperature of the substrate coupled to the pair of traces;
• and
• means for generating a digital value from the output coupled to the means for generating an output.