Inkjet recording apparatus

Abstract

An inkjet recording apparatus comprises an inkjet recording head, an ink-testing unit having an ink-test chamber, a pressure-vibration generating unit that generates a pressure vibration in the ink-test chamber, a pressure-vibration detecting unit that detects the pressure vibration, an ink inlet that introduces ink into the ink-test chamber and an ink outlet through which ink is discharged from the ink-test chamber. Failures of ink ejection can be prevented by detecting cavitation cores by the ink-test chamber and removing ink containing the cavitation cores from ink supplied to the inkjet recording head.

1 . An inkjet recording apparatus, comprising:
 an inkjet recording head including a nozzle from which ink is ejected, a pressure chamber fluidly communicated with the nozzle, an ink supply unit that supplies ink to the pressure chamber, and actuators that vary a capacity of the pressure chamber;   an ink unit which includes an ink chamber, a pressure-vibration generating unit for generating a pressure vibration in the ink chamber, a pressure-vibration detecting unit for detecting an ink pressure-vibration in the ink chamber, an ink inlet introducing ink into the ink chamber, and an ink outlet through which ink is discharged from the ink chamber; and   a path for fluidly connecting the ink supply unit and the ink outlet.   
   
   
       2 . The inkjet recording apparatus according to  claim 1 , wherein a lower limit of a pressure of a pressure vibration generated within the ink chamber is set to be lower than a lower limit of a pressure of a pressure vibration generated within the pressure chamber. 
   
   
       3 . The inkjet recording apparatus according to  claim 1 , wherein the ink unit has an ink chamber surrounded by a frame having the ink-testing chamber therein, a first vibration plate that is secured to one surface of frame, a second vibration plate that is secured to the other surface of frame. 
   
   
       4 . The inkjet recording apparatus according to  claim 3 , wherein the ink unit has a piezoelectric member that is secured to the first vibration plate to generate a pressure vibration in the ink. 
   
   
       5 . The inkjet recording apparatus according to  claim 3 , wherein the ink unit has a piezoelectric member that is secured to the second vibration plate to detect an ink pressure vibration in the ink. 
   
   
       6 . The inkjet recording apparatus according to  claim 3 , wherein an ink inlet and an ink outlet are formed within vibration plate. 
   
   
       7 . The inkjet recording apparatus according to  claim 6 , wherein the ink inlet and the ink outlet are respectively connected to tubes formed of a flexible material. 
   
   
       8 . An inkjet recording apparatus, comprising:
 an inkjet recording head ejecting ink;   an ink unit for pressurizing ink to be supplied to the inkjet recording head and detecting an ink pressure-vibration in the ink; and   an ink-discharging unit that discharges the ink based on a result of the detected pressure vibration, the ink-discharging unit being fluidly connected between the ink unit and the inkjet recording head.   
   
   
       9 . The inkjet recording apparatus according to  claim 8 , wherein a plurality of the ink units and a plurality of the ink-discharging units are provided and the plurality of ink units are disposed in parallel, each of the ink units being coupled with one of the ink-discharging units. 
   
   
       10 . The inkjet recording apparatus according to  claim 8 , further comprising an ink-reproducing unit for reproducing ink that is discharged through the ink-discharging unit, wherein the ink reproduced by the reproduction unit is supplied to the inkjet recording head. 
   
   
       11 . The inkjet recording apparatus according to  claim 8 , wherein the ink-discharging unit is composed of magnetic valve. 
   
   
       12 . The inkjet recording apparatus according to  claim 8 , wherein the ink unit includes an ink chamber, a pressure-vibration generating unit for generating a pressure vibration in the ink chamber, a pressure-vibration detecting unit for detecting an ink pressure-vibration in the ink chamber, an ink inlet introducing ink into the ink chamber, and an ink outlet through which ink is discharged from the ink chamber. 
   
   
       13 . The inkjet recording apparatus according to  claim 8 , wherein the inkjet recording head includes a nozzle from which ink is ejected, a pressure chamber fluidly communicated with the nozzle, an ink supply unit that supplies ink to the pressure chamber, and actuators that vary a capacity of the pressure chamber. 
   
   
       14 . The inkjet recording apparatus according to  claim 13 , wherein a lower limit of a pressure of a pressure vibration generated within the ink chamber is set to be lower than a lower limit of a pressure of a pressure vibration generated within the pressure chamber. 
   
   
       15 . An inkjet recording method, comprising:
 preparing an inkjet recording head ejecting ink;   supplying ink to an ink unit for pressurizing ink to be supplied to the inkjet recording head;   pressurizing the ink in the ink unit;   detecting an ink pressure-vibration in the ink in the ink unit; and   discharging the ink supplied to the ink based on a result of the detected pressure vibration.   
   
   
       16 . The inkjet recording method according to  claim 15 , wherein a lower limit of a pressure of a pressure vibration generated within the ink chamber is set to be lower than a lower limit of a pressure of a pressure vibration generated in the ink in the inkjet head to eject an ink from the inkjet recording head.