Liquid ejection apparatus

Abstract

The present invention provides a liquid ejection apparatus capable of precisely controlling a flow rate of liquid in a flow-path. The liquid ejection apparatus is equipped with: an ejection head that is provided with a feed port and a discharge port, and that ejects fed liquid; a feed flow-path that feeds liquid to the feed port; a discharge flow-path that discharges liquid from the discharge port; at least one of the feed flow-path and/or the discharge flow-path equipped with a main pump that pumps a constant flow rate of liquid in the flow-path, a sub pump provided in parallel to the main pump and that pumps liquid in the flow-path, and a detector unit that detects liquid pressure in the flow-path; and a control unit that controls the flow rate of liquid pumped by the sub pump such that the pressure detected achieves a predetermined pressure.

1 . A liquid ejection apparatus comprising:
 an ejection head including a feed port for feeding liquid in and a discharge port for discharging liquid out, and that ejects fed liquid;   a feed flow-path that feeds liquid to the feed port; and   a discharge flow-path that discharges liquid from the discharge port;   wherein at least one of the feed flow-path or the discharge flow-path includes,
 a main pump that pumps a liquid at a constant flow rate in the at least one of the feed flow-path or the discharge flow-path, 
 a sub pump provided in parallel to the main pump and that pumps liquid in the at least one of the feed flow-path or the discharge flow-path, and 
 a detector unit that detects pressure of liquid in the at least one of the feed flow-path or the discharge flow-path; and 
   wherein the liquid ejection apparatus further comprises, a control unit that controls the flow rate of liquid pumped by the sub pump such that the liquid pressure detected in the at least one of the feed flow-path or the discharge flow-path achieves a predetermined pressure.   
   
   
       2 . The liquid ejection apparatus of  claim 1 , wherein:
 each of the feed flow-path and the discharge flow-path respectively include the main pump; and   a common drive source is used for driving the main pump.   
   
   
       3 . A liquid ejection apparatus comprising:
 an ejection head including a feed port for feeding liquid in and a discharge port for discharging liquid out, and that ejects fed liquid;   a feed flow-path that feeds liquid to the feed port;   a discharge flow-path that discharges liquid from the discharge port;   a main pump that pumps liquid at constant flow rate of liquid in the feed flow-path and in the discharge flow-path;   a sub pump provided in parallel to the main pump and that pumps liquid in the feed flow-path and in the discharge flow-path;   a first detector unit that detects liquid pressure in the feed flow-path;   a second detector unit that detects liquid pressure in the discharge flow-path; and   a control unit that controls the flow rate of liquid pumped by the sub pump such that the liquid pressures detected in the feed flow-path and in the discharge flow-path are within a predetermined pressure range.   
   
   
       4 . A method for controlling liquid ejection comprising:
 providing a liquid ejection control apparatus including, an ejection head that includes a feed port and a discharge port, and that ejects fed liquid, a feed flow-path that feeds liquid to the feed port, a discharge flow-path that discharges liquid from the discharge port, a main pump that pumps liquid at a constant flow rate in the feed flow-path and in the discharge flow-path, a sub pump provided in parallel to the main pump and that pumps liquid in the feed flow-path and in the discharge flow-path, a first detector unit that detects liquid pressure in the feed flow-path, a second detector unit that detects liquid pressure in the discharge flow-path, and a control unit that controls the flow rate of liquid pumped by the sub pump;   controlling the flow rate of liquid pumped by the sub pump such that the liquid pressure detected by the first detector unit is within a predetermined pressure range; and   controlling the flow rate of liquid pumped by the sub pump such that the liquid pressure detected by the second detector unit is within the predetermined pressure range.