Hewlett-packard Development Company, L.p.

Other

Pere Tuset

Xavier Vilajosana

Sheila Cabello

Pol Fornos

Diego Javier Mostaccio

In an example, a method of anticipating maintenance in a printing device includes determining an inertial reference signal of a printer carriage and measuring a current inertial signal of the printer carriage. The method includes cross-correlating the inertial reference signal with the current inertial signal and determining from the cross-correlating when the current inertial signal is not within a preset confidence interval of the inertial reference signal.

Anticipating maintenance in a printing device

In an example, a print apparatus includes a printhead carriage to receive a printhead comprising a print agent ejection nozzle, a drop detector to acquire a signal indicative of variations in a parameter detected by the drop detector over a period of drop detection, a memory to hold a print agent ejection signature, and processing circuitry. The processing circuitry includes a convolution module to convolve the drop detector signal with the print agent ejection signature, and the processing circuitry is to determine, from an output of the convolution module, an indication of similarity between the drop detector signal and the print agent ejection signature.

Indications of similarity for drop detector signals

In some examples, a method comprises sensing a temperature of a plurality of sub-regions of a portion of a layer of build material in an object generation apparatus. A frequency distribution of sub-region temperatures may be derived therefrom and it may be determined whether the frequency distribution is bimodal. If the frequency distribution is not bimodal, a build material temperature zone is identified. If however the frequency distribution is bimodal, a fusing build material temperature zone and a non-fusing build material temperature zone are identified. The method may further comprise determining a nominal temperature of the at least one identified temperature zone.

Object generation temperature measurement

In an example, a printhead maintenance apparatus includes a pump, a current monitor and processing circuitry. The pump may be provided to increase a pressure in a printhead, and the current monitor may monitor a current consumption of the pump. The processing circuitry may determine a rate of change of current consumption of the pump, and compare the rate of change of current consumption to a predetermined threshold.

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Sant Cugat del Valles, Spain

Pere Tuset