公开(公告)号：US10183484B2

公开(公告)日：2019-01-22

申请号：US15493960

申请日：2017-04-21

Applicant: OCE-TECHNOLOGIES B.V.

Inventor： Hylke Veenstra ,  Marko Mihailovic ,  Cornelis W. M. Venner ,  Amol A. Khalate ,  Tjerk E. C. Hummel

IPC: B41J2/045 ,  B41J2/21 ,  B41J2/165 ,  B41J2/14 ,  B41J2/325 ,  B41J2/355

Abstract: 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.

公开(公告)号：US10144215B2

公开(公告)日：2018-12-04

申请号：US15643212

申请日：2017-07-06

Applicant: OCE-TECHNOLOGIES B.V.

Inventor： Marko Mihailovic ,  Tjerk E. C. Hummel ,  Johannes M. M. Simons ,  Hylke Veenstra ,  Cornelis W. M. Venner ,  Amol A. Khalate

IPC: B41J2/045 ,  B41J2/14

Abstract: 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.