Abstract: According to one embodiment, a driving device includes a head driver configured to generate and apply a driving signal to an actuator for ejecting a liquid from a pressure chamber connected to a nozzle, the driving signal including a contraction pulse, the contraction pulse causing the actuator to contract a volume of the pressure chamber, and end application of the contraction pulse when a flow rate of the liquid from the nozzle has a negative value in a liquid ejection direction from the nozzle.

Abstract: According to one embodiment, a fluid discharge head includes a pressure chamber, an actuator, and an application unit. The pressure chamber accommodates a fluid. The application unit applies the driving signal for discharging a fluid from a nozzle communicating with the pressure chamber to the actuator. The driving signal includes a first pulse for driving the actuator to decrease the pressure of the fluid in the pressure chamber and a second pulse for driving the actuator to increase the pressure of the fluid in the pressure chamber. When a half period of a natural oscillation period of the fluid in the pressure chamber is AL, an application time T of the first pulse satisfies a condition of T<AL. A ratio between a voltage of the first pulse and a voltage of the second pulse is ?0.95 to ?1.05.

Abstract: According to one embodiment, a driving device includes a head driver configured to generate and apply a driving signal to an actuator for ejecting a liquid from a pressure chamber connected to a nozzle, the driving signal including a contraction pulse, the contraction pulse causing the actuator to contract a volume of the pressure chamber, and end application of the contraction pulse when a flow rate of the liquid from the nozzle has a negative value in a liquid ejection direction from the nozzle.

Abstract: A circulating type ink supply system includes an upstream ink tank, an upstream ink flow channel connected at one end thereof to the upstream ink tank, a nozzle branch portion connected to the other end of the upstream ink flow channel and being in communication with a nozzle configured to discharge ink, a downstream ink flow channel connected at one end thereof to the nozzle branch portion and a downstream ink tank connected to the other end of the downstream ink flow channel, wherein an energy per unit volume determined by a sum value of a static pressure and a potential energy of the ink in the upstream ink tank when the circulation of the ink is stopped does not exceed the energy per unit volume of the ink at an atmospheric pressure at a level of the nozzle.

Abstract: A circulating type ink supply system includes an upstream ink tank, an upstream ink flow channel connected at one end thereof to the upstream ink tank, a nozzle branch portion connected to the other end of the upstream ink flow channel and being in communication with a nozzle configured to discharge ink, a downstream ink flow channel connected at one end thereof to the nozzle branch portion and a downstream ink tank connected to the other end of the downstream ink flow channel, wherein an energy per unit volume determined by a sum value of a static pressure and a potential energy of the ink in the upstream ink tank when the circulation of the ink is stopped does not exceed the energy per unit volume of the ink at an atmospheric pressure at a level of the nozzle.

Abstract: An ink jet printing apparatus includes a table which places a print medium on, a switching unit which switches the print medium to a fixed state or a released state with respect to the table, a carrying unit which carries the table, at least one or more print heads which eject ultraviolet curable ink, a first UV curing unit which is provided downstream from each of the print heads along a direction of carrying the table from an initial position toward the print heads and casts ultraviolet rays to provisionally cure the ultraviolet curable ink, and a second UV curing unit which is provided downstream from the first UV curing unit provided on the most downstream side along the direction of carrying the table from the initial position toward the print heads and casts ultraviolet rays to fully cure the ultraviolet curable ink.