A print element substrate, comprising a plurality of heating elements, a plurality of detection elements, each configured to detect a temperature of a corresponding heating element, a first current generation unit, a second current generation unit, and a signal output unit, wherein one of the first and second current generation units supplies a current to a first detection element, the other supplies a current to a second detection element, and the signal output unit outputs a signal according to a potential difference between one terminal of the first detection element on a side where a potential variation occurs upon supply of the current and one terminal of the second detection element on a side where a potential variation occurs upon supply of the current.

A fluid dispensing system with a fluid cartridge having a fluid reservoir and an ejection head. The ejection head has fluid ejectors that are in fluid flow communication with the fluid reservoir. A fluid detection circuit is electrically connected to at least one of the fluid ejectors. The fluid detection circuit is configured to detect and characterize a fluid in the fluid ejector, where the fluid detection circuit characterizes the resistivity of the fluid by adjusting an ejector voltage of the at least one of the fluid ejectors.

A liquid droplet discharge apparatus includes: a metallic discharge head configured to discharge a liquid droplet onto a print medium; an electrode arranged facing the discharge head; a voltage source configured to generate a potential difference between the discharge head and the electrode; a current detection part configured to detect a current flowing between the discharge head and the electrode; and a controller. The controller is configured to calculate a volume of the liquid droplet based on a current value detected by the current detection part, in a case that the liquid droplet is discharged from the discharge head in a state that the potential difference is generated between the discharge head and the electrode by the voltage source.

A liquid ejection apparatus includes a controller configured to perform: causing a voltage application circuit to apply a voltage between a liquid ejection head having a plurality of nozzles and an electrode; driving the liquid ejection head for causing a certain nozzle to eject liquid toward a cap in a state where the plurality of nozzles face the cap; receiving a signal from a signal output circuit; determining, based on the received signal, whether the certain nozzle has ejected liquid normally; determining, based on the received signal, whether a leakage current has occurred between the certain nozzle and the electrode; and specifying the certain nozzle as a leakage nozzle if the leakage current has occurred between the certain nozzle and the electrode.

A fluid dispensing system with a fluid cartridge having a fluid reservoir and an ejection head. The ejection head has fluid ejectors that are in fluid flow communication with the fluid reservoir. A fluid detection circuit is electrically connected to at least one of the fluid ejectors. The fluid detection circuit is configured to detect and characterize a fluid in the fluid ejector, where the fluid detection circuit characterizes the resistivity of the fluid by adjusting an ejector voltage of the at least one of the fluid ejectors.

An integrated circuit to drive a number of fluid actuation devices, comprising a circuit configured to have a memory access state which can be set to one of an enabled state and disabled state. The integrated circuit to include a fluid actuation circuit to transmit selection information for a fluid actuation device, the selection information comprising a data state bit. The integrated circuit to include a memory cell array, configured so that each memory cell is accessible by the memory access state being enabled, and the data state bit being set.

An integrated circuit to drive a plurality of fluid actuation devices includes a contact pad and a programmable pulldown device. The programmable pulldown device is electrically coupled to the contact pad. The programmable pulldown device is settable to any one of a plurality of resistances.

A memory circuit for a print component including a plurality of I/O pads, including an analog pad, to connect to a plurality of signal paths which communicate operating signals to the print component. The memory circuit includes a controllable selector connected in line with one of the signal paths via the I/O pads, the selector controllable to disconnect the corresponding signal path to the print component, and a memory component to store memory values associated with the print component. A control circuit, in response to a sequence of operating signals received by the I/O pads representing a memory read, to operate the controllable selector to disconnect the signal path to the print component to block the memory read of the print component, and provide an analog signal to the analog pad to provide an analog electrical value at the analog pad representing stored memory values selected by the memory read.

An integrated circuit to drive a plurality of fluid actuation devices includes a plurality of contact pads, a plurality of pulldown devices, and control logic. The plurality of contact pads include a first contact pad and a second contact pad. Each of the pulldown devices is electrically coupled to a corresponding contact pad. The control logic enables at least a portion of the pulldown devices in response to both a logic low signal on the first contact pad and a logic low signal on the second contact pad.

A fluidic die includes fluid chambers, each including an electrode exposed to an interior of the fluid chamber and each having a corresponding fluid actuator operating at a high voltage. The fluidic die further includes monitoring circuitry, operating at a low voltage relative to the fluid actuator, to monitor a condition of each fluid chamber, for each chamber the monitoring circuitry including a connection structure and a select transistor and a pulldown transistor connected to the electrode via the connection structure. The connection structure and select and pulldown transistors together structured to form electrically conductive paths with electrical resistances to protect at least the select transistor from fault damage if the high voltage fluid actuator short-circuits to the electrode.