Hewlett-packard Development Company, L.P.

Neel Banerjee

Andrew L Van Brocklin

Ning Ge

Trudy L Benjamin

Joseph M Torgerson

George H Corrigan

Teck-Khim Neo

Eric T Martin

Jeffrey Todd Mabeck

Randy Hoffman

Kevin E Swier

Teck Khim Neo

Anton Nicholas Clarkson

David Pidwerbecki

Peter S Nyholm

Christopher Reimer

Judy Benjamin

Christopher A Reimer

In some examples, a method of sensing an ink level includes applying a pre-charge voltage to a sense capacitor to charge the sense capacitor with a charge, sharing the charge between the sense capacitor and a reference capacitor, causing a reference voltage at a gate of an evaluation transistor, and determining a resistance from a drain to a source of the evaluation transistor that results from the reference voltage.

Ink level sensing

In some examples, an ink level sensor includes a sense capacitor between a first node and ground, a first switch to couple a first voltage to the first node and charge the sense capacitor, a second switch to couple the first node with a second node and share the charge between the sense capacitor and a reference capacitor, causing a second voltage at the second node, and a transistor having a drain, a gate coupled to the second node, and a source coupled to ground, the transistor to provide a drain to source resistance in proportion to the second voltage.

In one example, a device for driving a nozzle of a fluid-jet printing device includes a circuit to, for each pixel time of a plurality of pixel times select a waveform from a plurality of waveforms based on more than one of waveform time delay, waveform pulse width and waveform shape, and apply the selected waveform to the nozzle to drive the nozzle to eject fluid for a current pixel time.

Waveform selection and/or scaling for driving nozzle of fluid-jet printing device

In an embodiment, a method of sensing an ink level includes applying a pre-charge voltage Vp to a sense capacitor to charge the sense capacitor with a charge Q, sharing Qbetween the sense capacitor and a reference capacitor, causing a reference voltage Vg at the gate of an evaluation transistor, and determining a resistance from drain to source of the evaluation transistor that results from Vg.

Ink level sensor and related methods

Technology is described for extending battery life for a rechargeable battery. The method can include estimating a desired energy storage for the rechargeable battery in an electronic device during an operating time period. Expected active periods for the rechargeable battery can be determined. A defined charge voltage can be computed based on the desired energy storage and expected active periods of the rechargeable battery in the electronic device. In addition, the rechargeable battery can be charged to the defined charge voltage.

Extending battery life for a rechargeable battery

A controller is for driving a nozzle of a fluid-jet printing device. The controller can select a waveform from a number of waveforms based at least on values for the nozzle. The controller can scale the waveform based on the values for the nozzle. The waveform drives the nozzle to cause the nozzle to eject fluid therefrom.

A battery temperature sensor may include a substrate and a thin film resistive temperature device (RTD). The substrate can be layered on a battery cell element. The battery cell element can be an anode, a cathode, and a separator between the anode and cathode used in a battery cell. The thin film resistive temperature device (RTD) on the flexible substrate can change resistance with a change in temperature. A battery cell housing can enclose the thin film RTD.

Battery temperature sensor

Crosstalk in a piezo printhead is reduced by storing a coefficient that expresses an amount of crosstalk between a first nozzle and an adjacent nozzle. A drive waveform voltage is pre-biased using the coefficient, and the pre-biased waveform is applied to a piezoelectric material of the first nozzle.

Crosstalk reduction in piezo printhead

Crosstalk in a piezo printhead is reduced by selecting an actuation signal for a nozzle, determining a time delay and a pulse width extension based on adjacent actuation signals of adjacent nozzles, and applying the time delay and pulse width extension to the actuation signal.

Methods and apparatus are provided related to thermal protection of electrical batteries. A sensor senses the temperature of a battery and a corresponding digital signal is digitally derived. Date, time and temperature data are written to storage media. A time-rate-of-change of the battery's temperature is determined and used to establish operational periodicity. Stored digital data can be communicated to another entity, temperature or time-rate-of-change values used to trigger an alarm or system shut-down, and so on. Electronic circuitry toggles between an active mode and a power-conserving sleep mode in accordance with periodic operating schedule.

Temperature sensing of electric batteries

In one embodiment, a drive waveform generator to control ejection of liquid from a set of ejection elements in single-pass printing. A first waveform source defines a first aspect of a drive waveform for the set of ejection elements and for other ejection elements. A second waveform source defines a second aspect of the drive waveform for the set of ejection elements but not for the other ejection elements. A circuit uses the first waveform source and the second waveform source to generate the drive waveform having the first and second aspects.

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Corvallis, OR, United States of America

Neel Banerjee