Oce-Technologies B.v.

Tjerk E C Hummel

Hylke Veenstra

Amol A Khalate

Cornelis W M Venner

Marko Mihailovic

Johannes M M Simons

Marc Paul Schuwer

Anthonius A J De Graaff

Etienne L M E Van Dorsselaer

A jetting device includes an ejection unit arranged to eject a droplet of a liquid. The ejection unit includes a nozzle, a liquid duct connected to the nozzle, and an electro-mechanical transducer arranged to create an acoustic pressure wave in the liquid in the duct. The jetting device further includes a filter arranged to filter the liquid being supplied into the duct and a filter status detection system arranged to detect an obstruction status of the filter by measuring a property of the liquid in the duct. The filter status detection system includes a circuit configured for measuring the electric response of the transducer, for recording changes in the electric response that represent pressure fluctuations induced by the acoustic wave in the form of a time-dependent function, and for judging the obstruction status of the filter on the basis of that function.

Jetting device with filter status detection

For assessing the functioning of an ejection unit of an inkjet print head, a comparison of a residual pressure wave with a residual pressure wave reference is employed. To enable assessment during printing, multiple residual pressure wave references are provided, each relating to a condition relevant to the residual pressure wave. Such a condition may relate to an actuation status of an adjacent ejection unit which may cause crosstalk, for example. When performing the assessment, the condition during assessment is taken into account, for example for selecting a suitable residual pressure wave reference, such that an appropriate and correct assessment can be performed independent from the conditions during assessment.

Method for detecting an operating state of an inkjet print head nozzle

An inkjet print head includes an ejection unit having a liquid chamber for holding an amount of liquid, a electromechanical transducer operatively coupled to the liquid chamber for generating a pressure wave in the amount of liquid and a nozzle in fluid communication with the liquid chamber for enabling a droplet of the amount of liquid to be ejected through the nozzle. A method for detecting an operating state of the ejection unit includes the consecutive steps of actuating the electromechanical transducer to generate a pressure wave in the liquid; actuating the electromechanical transducer to suppress a residual pressure wave in the liquid; sensing an amplitude of the residual pressure wave in the liquid; and based on the result of the sensing step determining that the ejection unit is (i) in an operative state if the amplitude of the residual pressure wave is below a threshold or (ii) in a malfunctioning state if the amplitude of the residual pressure wave is above the threshold.

Method for detecting an operating status of an inkjet nozzle

An image scanning and processing system includes a scanner for generating a stream of data encoding a scanned image; a controller for controlling and processing data received from the scanner; and a file storage unit. In use, the stream of data is written to a master file saved in the file storage unit. The controller is configured to create a preview image with a lower data size than the scanned image from at least part of the data encoding the scanned image. The controller is configured to extract data encoding the preview image directly from the stream of data, and to write the extracted data to a thumbnail file. A method of scanning and processing an image, includes scanning an original and thereby generating a stream of data, encoding a scanned image, saving the scanned image in a master file, and creating a preview image with a lower data size than the scanned image from at least part of the data encoding the scanned image. Data encoding the preview image is extracted from the stream of data, and written to a thumbnail file.

Image scanning and processing system, method of scanning and processing an image and method of selecting one of a plurality of master files comprising data encoding a scanned image

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Venlo, Netherlands

Tjerk E C Hummel