Liquid discharge device and method of controlling the same

1. A method of controlling a liquid discharge device,

wherein the liquid discharge device includes

a liquid discharge unit configured to discharge from a nozzle liquid supplied from at least one supply channel, and

at least one valve body configured to open/close the at least one supply channel, and

wherein the method includes

a first control step that causes a pressure to be applied to the liquid so as to supply the liquid to the at least one supply channel, and

a second control step that causes an external force to operate the at least one valve body operable in accordance with a pressure on a downstream side of the at least one valve body so as to adjust and hold a degree of opening of the at least one valve body in a range between a closed state and a full-open state,

wherein the liquid discharge device further includes a flexible film that operates the at least one valve body,

wherein the flexible film has a first surface that defines a portion of the at least one supply channel downstream of the at least one valve body and a second surface opposite to the first surface, and

wherein the at least one valve body operable by deformation of the flexible film occurring in accordance with a differential pressure between a pressure on the first surface side and a pressure on the second surface side is caused to be operated by deformation of the flexible film occurring due to an external force applied from the second surface side.

2. The method according to claim 1 ,

wherein the at least one supply channel includes a plurality of supply channels,

wherein the at least one valve body includes a plurality of valve bodies, and each of the plurality of valve bodies is provided for a corresponding one of the plurality of supply channels, and

wherein the first control is separately performed on each of the plurality of supply channels, and the second control is separately performed on each of the plurality of supply channels.

3. The method according to claim 2 ,

wherein the second control for the plurality of valve bodies is simultaneously performed.

4. The method according to claim 2 ,

wherein the external force in the second control is a pressure of air applied by a pump, and

wherein, in the second control, the degrees of opening of the plurality of valve bodies are separately adjusted by varying the pressure of the pump in accordance with respective target values of supply pressures of the liquid.

5. The method according to claim 4 ,

wherein a common air channel is connected to the pump, branch air channels respectively corresponding to the plurality of valve bodies are branched from the common air channel, and each of the branch air channels is provided with a corresponding one of solenoid valves, and

wherein, in the second control, the solenoid valves each adjust the pressure applied by the pump for a corresponding one of the branch air channels so as to adjust the degree of opening of a corresponding one of the plurality of valve bodies.

6. The method according to claim 5 ,

wherein a buffer chamber is provided in the common air channel,

wherein the second control includes

closing the solenoid valves and driving the pump so as to store the pressure of the air in the buffer chamber, and

opening the solenoid valves so as to adjust the degrees of opening of the plurality of valve bodies by the pressure of the air stored in the buffer chamber.

7. A method of controlling a liquid discharge device,

wherein the liquid discharge device includes

a liquid discharge unit configured to discharge from a nozzle liquid supplied from at least one supply channel, and

at least one valve body configured to open/close the at least one supply channel, and

wherein the method includes

a first control step that causes a pressure to be applied to the liquid so as to supply the liquid to the at least one supply channel, and

a second control step that causes an external force to operate the at least one valve body operable in accordance with a pressure on a downstream side of the at least one valve body so as to adjust and hold a degree of opening of the at least one valve body in a range between a closed state and a full-open state,

wherein the at least one supply channel includes a plurality of supply channels,

wherein the at least one valve body includes a plurality of valve bodies, and each of the plurality of valve bodies is provided for a corresponding one of the plurality of supply channels,

wherein the first control is separately performed on each of the plurality of supply channels, and the second control is separately performed on each of the plurality of supply channels, and

wherein the second control for the plurality of valve bodies is simultaneously performed.

8. The method according to claim 7 ,

wherein the external force in the second control is a pressure of air applied by a pump, and

wherein, in the second control, the degrees of opening of the plurality of valve bodies are separately adjusted by varying the pressure of the pump in accordance with respective target values of supply pressures of the liquid.

9. The method according to claim 8 ,

wherein a common air channel is connected to the pump, branch air channels respectively corresponding to the plurality of valve bodies are branched from the common air channel, and each of the branch air channels is provided with a corresponding one of solenoid valves, and

wherein, in the second control, the solenoid valves each adjust the pressure applied by the pump for a corresponding one of the branch air channels so as to adjust the degree of opening of a corresponding one of the plurality of valve bodies.

10. The method according to claim 9 ,

wherein a buffer chamber is provided in the common air channel,

wherein the second control includes

closing the solenoid valves and driving the pump so as to store the pressure of the air in the buffer chamber, and

opening the solenoid valves so as to adjust the degrees of opening of the plurality of valve bodies by the pressure of the air stored in the buffer chamber.