Hewlett-packard Development Company, L.p.

Ana Cristina Garcia Alvarez

Mauricio Seras Franzoso

Antonio Gracia Verdugo

Marta Coma Vives

Oriol Borrell Avila

Gonzalo Gaston Llado

Maurizio Bordone

Yit Hong Tor

Alexander Jose Perez Garcia

In an example, a surface inspection apparatus includes a light source to illuminate a portion of a surface in a print apparatus, a light detection apparatus and processing circuitry. The light detection apparatus may receive diffusely reflected light and specularly reflected light from the portion of the surface, and may comprise a detection element for detecting the specularly reflected light. The processing circuitry may comprise a comparison module to determine a relationship between an intensity of the detected diffusely reflected light and the detected specularly reflected light and a quality module to evaluate if the surface meets a quality criterion based on the relationship.

Evaluating surfaces

In an example, a printhead-wiping device comprises: a wiper element and a biasing mechanism, the biasing mechanism to bias the wiper element towards a printhead. An actuator may be used to adjust a preload force applied to the biasing mechanism. The preload force applied to the biasing mechanism may be controlled using a controller so as to control a wiping force applied by the wiper element against the printhead.

Printhead-wiping device

A printing apparatus includes a printhead having a nozzle to eject liquid and an actuator associated with the nozzle. A controller is provided to activate a recovery sequence including heating the printhead without firing drops in a first phase, activating the actuator to fire 1000 drops or more from the nozzle in a second phase after the first phase, and heating the printhead and applying pressure to expel liquid from the nozzle in a third phase after the second phase.

Printhead recovery

A printer is disclosed. The printer spits printing fluid from nozzles using a spit pattern. The spit pattern is non-uniform along the spit pattern length.

Non-uniform spitting

In some examples, a method includes, in response to a fluid firing unit being operated according to a normal printing mode, applying a first voltage to the fluid firing unit to fire the fluid firing unit during a printing operation. The method further includes determining, using a sensor, whether a predetermined condition is met, and in response to determining that the predetermined condition is met, operating the fluid firing unit according to a recovery mode in which a second voltage higher than the first voltage is applied to the fluid firing unit to clean the fluid firing unit.

Controlling a fluid firing unit of a printhead

The present disclosure discloses a method implemented by a printer to control a fluid firing unit of a printhead, when said printhead is coupled to the printer, to operate according to any one of a normal printing mode and a recovery mode. According to the method, if the fluid firing unit is operated according to the normal printing mode, a first voltage is applied to the fluid firing unit to fire the fluid firing unit during a printing operation; and if the fluid firing unit is operated according to the recovery mode, a second voltage higher than the first voltage is applied to the fluid firing unit to clean the fluid firing unit.

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Sant Cugat del Valles, Spain

Ana Cristina Garcia Alvarez