Study of Processing Accuracy of the Nickel Cavity Plate of Inkjet Print Headand Print Quality

Abstract

The issues with high-speed inkjet printer are important for personal and industrial printing. A large-sized print head with a greater number of fine nozzles for ejecting ink could conceivably be used as an effective measure. A print head is configured from stacks of plates which have accurate figures. When such a structure is applied for a large-sized head, the difference between the expansion coefficients of the nozzle plate and that of the cavity plate causes the deformation of the nozzle plate, which is thinner than the cavity plate with the process of time. We assume the deformation greatly influences the direction in which ink ejected from the nozzles travels, so that the direction of ejected ink droplets can be unstable and the print quality can deteriorate. To reduce the risk of the nozzle plate deformation, we produced the head using nickel for the cavity plate united with the nozzle plate instead of conventional silicon and evaluated the basic capabilities. The nozzle plate deformation was decreased by replacing the material of the cavity plate with nickel. However certain parts of some samples printed by the head showed the size variation of ink droplets that was visible to the naked eye. We thought the size variation of ink droplets was caused by ink droplets having a large weight variation that was generated during ink ejection, and the variation of ink weights has a correlation with the large difference among the depths of the pressure chambers and the thinness of the nickel cavity plate. We measured about the depths of the pressure chambers and the address, ink weights and the thickness in the experiments. To solve the size variation of ink droplets, we improved the variation of the depths of the pressure chambers and the thickness of the nickel cavity plate by developing the process method. As the result, the size variation of ink droplets reached a level that could not be detected by the naked eye. We clarified that the main cause was the depths of the pressure chambers and the variation of ink weights.