Method for operating a printing system

摘要

A printing system for printing a fluid includes a print head for ejecting droplets of the fluid; a first fluid storing section for storing a first amount of the fluid; a second fluid storing section for storing a second amount of the fluid, the second fluid storing section being in fluid communication to the pressure chamber in a power down situation; and a pre-tension device configured for arranging the second amount of the fluid in a pre-tension state in the second fluid storing section, thereby providing a positive fluid pressure on the nozzle in a power down situation, which positive fluid pressure is selected such that a third amount of fluid passes through the nozzle in response to said positive fluid pressure and forms a film on the nozzle plate. The printing system according to the invention supports the recovery of the print head after a power down situation.

主权项

1. A printing system for printing a fluid, the printing system comprising:
a print head for ejecting droplets of the fluid, the print head comprising a pressure chamber, the pressure chamber in printing operation containing the fluid, and a nozzle plate which comprises a nozzle, the pressure chamber being in fluid communication with the nozzle, the nozzle containing a meniscus of the fluid; a first fluid storing section, in printing operation containing a first amount of the fluid, the first fluid storing section being in fluid communication to the fluid in the pressure chamber, the first amount of the fluid being arranged lower with respect to the nozzle, wherein lower is defined with respect to the gravity force acting downwards in a direction towards a ground level, thereby providing a negative fluid pressure on the meniscus of the fluid in the nozzle; a second fluid storing section configured for storing a second amount of the fluid, the second fluid storing section in a power down situation being arranged in fluid communication to the pressure chamber; and a pre-tension mechanism configured for:
in printing operation, arranging the second amount of the fluid in a pre-tension state in the second fluid storing section, and retaining in printing operation the second amount of the fluid inside the second fluid storing section in the pre-tension state, thereby in printing operation restraining the positive fluid pressure from acting on the meniscus of the fluid in the nozzle, andin the power down situation, stop retaining the second amount of fluid inside the second fluid storing section, wherein said pre-tension state of the second amount of fluid provides a positive fluid pressure on the meniscus of the fluid in the nozzle in response to the power down situation, and the positive fluid pressure is selected such that a third amount of the fluid passes through the nozzle in response to said positive fluid pressure and forms a film on the nozzle plate, and wherein the pre-tension mechanism is controlled such that in the power-down situation, the positive fluid pressure of the pre-tension state is provided on the meniscus of the fluid in the nozzle for forming the film on the nozzle plate.