Coating surfaces by a printing method

Abstract

A method of applying a homogeneous layer of a coating material on a surface with a manually operated application device is presented, the device comprising a number of drop-on-demand printing nozzles perpendicularly to a main direction of movement, with means for measuring the movement with respect to the surface and with an electronic printing nozzle control, characterized by the steps, that an operator makes a selection of the printing nozzles, that the application device gives the operator feedback on the selection made, that the operator moves the application device over the surface, wherein the movement of the application device is measured continuously, that the selected print nozzles are driven with a clock rate that is based on their respective speed and which is configured that successive printing dots overlap, and that those nozzles of the selection, which have a negative velocity component with respect to the main direction of movement, are not be actuated.

1 . A method of applying a homogeneous layer of a coating material on a surface with a manually operated application device comprising a number of drop-on-demand printing nozzles perpendicularly to a main direction of movement, with means for measuring the movement with respect to the surface and with an electronic printing nozzle control, characterized by the steps,
 that an operator makes a selection of the printing nozzles   that the application device gives the operator feedback on the selection made,   that the operator moves the application device over the surface, wherein the movement of the application device is measured continuously,   that the selected print nozzles are driven with a clock rate that is based on their respective speed and which is configured that successive printing dots overlap, and that those nozzles of the selection, which have a negative velocity component with respect to the main direction of movement, are not be actuated.   
     
     
         2 . A method according to  claim 1 , characterized in that at least two nozzles of the selection are driven with selection a different clock rate. 
     
     
         3 . A method according to  claim 1 , characterized in that the discharge of coating material from nozzles having a the movement component perpendicular to the main direction is reduced. 
     
     
         4 . A method according to  claim 1 , characterized in that the drop-on-demand printing nozzles discharge spray dots of the coating material. 
     
     
         5 . A method according to  claim 1 , characterized in that the application device is moved on the surface by means of rollers which have radially outwardly directed spikes or teeth. 
     
     
         6 . A method according to  claim 1 , characterized in that it is moved by means of rollers on the surface, whereas the surfaces of the rolls  3  that are in contact with the surface are hydrophobic. 
     
     
         7 . A method according to  claim 1 , characterized in that the application device is moved by means of rolls on the surface and for determining the movement speed the measured rotation speed of one or more rollers is used. 
     
     
         8 . A method according to  claim 1 , characterized in that the application device is moved by means of casters on the surface. 
     
     
         9 . A method according to  claim 8 , characterized in that the pivot bearing at least one pivot roller is temporarily locked. 
     
     
         10 . A method according to  claim 1 , characterized in that the printing nozzles  2  include an array of micro-electro-pneumatic transducers which actuates an array of drop-on-demand printing nozzles  2  pneumatically. 
     
     
         11 . Manual application device, with a series of drop-on-demand printing nozzles which are arranged perpendicular to a main direction of movement, means for measuring the velocity relative to the surface, for carrying out the method according to  claim 1 , comprising
 Input means for manual selection of print nozzles,   Output means for displaying the selection,   a control unit for generating at least two clock signals of different frequency for controlling printing nozzles,   at least one roller with radially outwardly directed spikes or teeth arranged on the circumference.