Patent ID: 8511802
Filing Date: 2013-08-20
Classification: B41J

Abstract:
1. A directivity detection device for detection of trajectories of drops issuing from a liquid jet, the drops being charged electrically, the device comprising: an electrostatic sensor comprising an electrically sensitive portion configured to detect an electrical charge, the electrically sensitive portion made of an electrically conductive material, the sensitive portion surrounded by an insulating portion made of electrically insulating material, the insulating portion being surrounded by an electric shielding portion made of electrically conductive material and connected to ground; the zones of the sensor delimiting at least one continuous flat surface, the sensitive zone of the sensor comprising at least four edges including an upstream edge and a downstream edge connected to one another by two lateral edges, the arrangement of the sensor being such that: a signal-processing unit configured to process the electrical signal generated by the electrical charges of the drops through movement detected by the sensor, the signal processing unit being configured to: wherein the first comparison is indicative of the actual position of a trajectory of drops in a plane parallel to the flat surface of the sensor and the second comparison is indicative of the actual position of the same trajectory of drops in a plane perpendicular to the flat surface of the sensor.