Patent ID: 9044941
Filing Date: 2015-06-02
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 being 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; for said first side, respectively said second side, of the sensor, the segment of the upstream edge and the segment of the downstream edge are of different lengths, the length of the longer segment, among the segment of the upstream edge and the segment of the downstream edge, being at least equal to the maximum permissible amplitude of the offset of trajectories to said first side, respectively to said second side, relative to the nominal trajectory, and the length of the shorter segment, among the segment of the upstream edge and the segment of the downstream edge, being at most equal to the maximum permissible amplitude of the offset of trajectories, to the first side, respectively, to the second side, relative to the nominal trajectory; 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: