The liquid ejection head includes a plurality of element substrates including first and second element substrates and an electrical wiring substrate. The first and second element substrates each has a heating element array in which a plurality of heating elements producing heat energy for liquid ejection is arrayed, an electrically conductive protection layer covering the plurality of heating elements, an insulating layer arranged between the plurality of heating elements and the electrically conductive protection layer, and a connecting terminal for connecting to the outside. The electrical wiring substrate is electrically connected with the first and second element substrates via the connecting terminal. On the first and second element substrates, the connecting terminal includes a connecting terminal for the electrically conductive protection layer, and the electrically conductive protection layer is electrically connected to a common wiring provided on the electrical wiring substrate via the connecting terminal.

Disclosed is a print head driving apparatus including: a print head unit having a plurality of heater resistors arranged therein, the plurality of heater resistors being divided into sub groups; a counter configured to sequentially generate code signals corresponding to the sub groups, using a driving clock signal; a driving signal generation unit configured to generate a driving signal for the heater resistors included in each of the sub groups, using the code signal; and a head control unit configured to extract heater resistors to which the driving signal is inputted, among heater resistors corresponding to input image data, and drive the extracted heater resistors.

A thermal inkjet dye sublimation ink consists of a disperse dye colorant dispersion, primary and secondary solvents, a chelating agent, oleth-3-phosphate, additive(s), and water. The colorant dispersion is present in an amount ranging from about 1 wt % actives to about 7 wt % actives. The amount of the primary solvent (glycerol, ethoxylated glycerol, 2-methyl-1,3-propanediol, dipropylene glycol, or combinations thereof) ranges from about 10 wt % to about 22 wt %, and the amount of the secondary solvent ranges from 0 wt % to about 7 wt %. The chelating agent amount ranges from 0 wt % actives to less than 0.1 wt % actives, and the oleth-3-phosphate amount ranges from about 0.1 wt % to about 0.75 wt. The additive is selected from the group consisting of a buffer, a biocide, another surfactant, and combinations thereof.

An inkjet ink includes: (i) a disazo dye of formula (I): ##STR00001##
(ii) 1,3-propanediol; (iii) a glycol compound selected from the group consisting of: triethylene glycol and tetraethylene glycol; and (iv) water. The ink has low toxicity and is preferably absent ethylene glycol and sulfolane.

A thermal bubble inkjet print head chip has a substrate (11), a heating resistor (12) formed at a first side of the substrate, and an ink accommodating cavity (13) formed at one side of the heating resistor distant from the substrate. A low heat conduction cavity (14) is formed in the substrate; the low heat conduction cavity is located at one side of the heating resistor distant from the ink accommodating cavity; the low heat conduction cavity is filled with a material having a heat conduction efficiency lower than the substrate. By means of the low heat conduction cavity, the amount of heat generated by the heating resistor and diffusing to the substrate is reduced, and the heating efficiency of the heating resistor is improved; therefore, the working current of the heating resistor can be correspondingly lowered.

Fluid ejection devices with multiple activation modes are disclosed. An example printhead assembly includes a fluid ejection nozzle, a first resistor fluidically coupled to the fluid ejection nozzle, and a second resistor fluidically coupled to the fluid ejection nozzle. The example printhead also includes an addressing circuit to receive a nozzle address and an activation mode to activate the fluid ejection nozzle. The activation mode determines which of the first resistor and the second resistor are to be energized.

Fluid ejection devices with multiple activation modes are disclosed. An example printhead assembly includes a fluid ejection nozzle, a first resistor fluidically coupled to the fluid ejection nozzle, and a second resistor fluidically coupled to the fluid ejection nozzle. The example printhead also includes an addressing circuit to receive a nozzle address and an activation mode to activate the fluid ejection nozzle. The activation mode determines which of the first resistor and the second resistor are to be energized.

A liquid discharge head substrate, comprising a discharging element configured to discharge a liquid, a driver configured to drive the discharging element, a conductive protection film covering the discharging element via an insulating film, and a controller connected to the protection film and configured to output a control signal that sets the driver in an inactive state when a change of a voltage of the protection film or a change in a current that flows to the protection film is detected.

Influence of transform of quality to an entire liquid discharge head is suppressed when a heat resistor and a covering portion are electrically connected to each other. To address this problem, a liquid discharge head substrate includes fuse portions for respective heat resistor arrays.

Provided is an electric wiring member supported by a support member that supports a recording element substrate configured to eject a liquid. The electric wiring member has a signal line for transmitting a drive signal used for driving the recording element substrate, a power line for supplying drive power to the recording element substrate, and a heat generating resistive line for heating the support member. The power line is arranged between the signal line and the heat generating resistive line.