Inkjet recording apparatus

Patent metadata

Field	Value
Publication number	US-10703108-B2
Application number	US-201916243179-A
Country	US
Kind code	B2
Filing date	Jan 9, 2019
Priority date	Jan 15, 2018
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

An inkjet recording apparatus, which can enhance the reliability of the phase search result to detect the optimal timing when the ink particles are electrically charged by the electrification electrode and secure the stable printing quality, is provided. The inkjet recording apparatus includes an ink receptacle in which a printing ink for an object to be printed is received; a nozzle which is connected to the ink receptacle and from which the ink fed under pressure is discharged; an electrification electrode to make ink particles discharged from the nozzle electrically charged; an electrification signal generation unit to generate an electrification signal to make the electrification electrode electrically charged; deflection electrodes to make the ink particles electrically charged by the electrification electrode deflect; a gutter to recover the ink unused for the printing; and a control unit to control operations of the inkjet recording apparatus as a whole; a first electric charge detection section to detect an amount of electric charge in accordance with the electrically charged ink particles between the electrification electrode and the deflection electrodes; and a second electric charge detection section to detect an amount of electric charge of the ink flowing within the gutter.

First claim

What is claimed is:

1. An inkjet recording apparatus comprising:
an ink receptacle in which a printing ink for an object to be printed is received;
a nozzle which is connected to the ink receptacle and from which the ink fed under pressure is discharged;
an electrification electrode to make ink particles discharged from the nozzle electrically charged;
an electrification signal generation unit to generate an electrification signal to make the electrification electrode electrically charged;
deflection electrodes to make the ink particles electrically charged by the electrification electrode deflect;
a gutter to recover the ink unused for the printing;
a control unit to control operations of the inkjet recording apparatus as a whole;
a first electric charge detection section to detect an amount of electric charge in accordance with the electrically charged ink particles between the electrification electrode and the deflection electrodes;
a second electric charge detection section to detect an amount of electric charge of the ink flowing within the gutter; and
a determination section to determine a level of the amount of electric charge detected by the second electric charge detection section;
wherein the control unit stops the ink from being jetted from the nozzle when the control unit determines that the level does not go beyond a threshold set by the determination section.

2. The inkjet recording apparatus according to claim 1 , wherein the second electric charge detection section is disposed farther downstream where the ink is recovered than a location where the ink particles drop with respect to the gutter.

3. The inkjet recording apparatus according to claim 1 , wherein the control unit controls a timing when the electrification signal is generated by the electrification signal generation unit based on a detection result according to the first electric charge detection section.

4. The inkjet recording apparatus according to claim 1 , wherein the control unit makes a comparison between a value of the amount of electric charge detected by the first electric charge detection section and a value of the amount of electric charge detected by the second electric charge detection section as well as a comparison between a timing when the electric charge is detected by the first electric charge detection section and a timing when the electric charge is detected by the second electric charge detection section; and adjusts pressure applied to the ink to be fed to the nozzle based on a result of the comparisons.

5. The inkjet recording apparatus according to claim 1 , wherein the control unit makes a comparison between a value of the amount of electric charge detected by the first electric charge detection section and a value of the amount of electric charge detected by the second electric charge detection section as well as a comparison between a timing when the electric charge is detected by the first electric charge detection section and a timing when the electric charge is detected by the second electric charge detection section; and adjusts a temperature of the ink to be fed to the nozzle based on a result of the comparisons.

6. The inkjet recording apparatus according to claim 1 , wherein the control unit makes a comparison between a value of the amount of electric charge detected by the first electric charge detection section and a value of the amount of electric charge detected by the second electric charge detection section as well as a comparison between a timing when the electric charge is detected by the first electric charge detection section and a timing when the electric charge is detected by the second electric charge detection section; and adjusts viscosity of the ink to be fed to the nozzle based on a result of the comparisons.

7. The inkjet recording apparatus according to claim 1 , wherein all the ink particles are not electrically charged, but at least one non-charged ink particle intervenes between the ink particles electrically charged in accordance with the electrification in terms of the amount of electric charge detected by the first electric charge detection section.

8. An inkjet recording apparatus comprising:
an ink receptacle in which a printing ink for an object to be printed is received;
a nozzle which is connected to the ink receptacle and from which the ink fed under pressure is discharged;
an electrification electrode to subject the ink discharged from the nozzle to electrification;
deflection electrodes to make the ink subjected to the electrification by the electrification electrode deflect;
a gutter to recover the ink unused for the printing; and
an electric charge detection section to detect an amount of electric charge in accordance with the electrification between the electrification electrode and the deflection electrodes,
wherein the electric charge detection section is formed with an insulator between a sensor for electric charge detection and an ink beam discharged from the nozzle; and the sensor for electric charge detection is fixed in a state where the sensor makes contact with the insulator.

9. The inkjet recording apparatus according to claim 8 , wherein the electric charge detection section is pushed by an elastic member provided on a side opposed to the insulator for the sensor for electric charge detection so as to be brought into contact with the insulator.

10. An inkjet recording apparatus comprising:
an ink receptacle in which a printing ink for an object to be printed is received;
a feeding pump which suctions the ink through a piping from the ink receptacle and feeds the ink under pressure to a nozzle to discharge the ink;
a pressure regulating valve which is disposed between the feeding pump and the nozzle and adjusts pressure applied to the ink within a piping path;
a pressure sensor to detect the pressure applied to the ink;
an electrification electrode to subject the ink discharged from the nozzle to electrification;
deflection electrodes to make the ink subjected to the electrification by the electrification electrode deflect;
a gutter to recover the ink unused for the printing; and
an electric charge detection section to detect an amount of electric charge in accordance with the electrification,
wherein the pressure regulating valve is provided with a pressure adjustment shaft, a pressure adjustment shaft gear integrally rotating with the pressure adjustment shaft, a driving gear disposed in a state where the driving gear is engaged with the pressure adjustment shaft gear, and a driving motor for rotating the driving gear.

11. The inkjet recording apparatus according to claim 10 , wherein frontal and rear sides of the pressure adjustment shaft are respectively retained with a bearing with respect to the pressure adjustment shaft gear.

12. The inkjet recording apparatus according to claim 10 , wherein the driving motor is subjected to driving control based on a detection result of the pressure sensor.

13. The inkjet recording apparatus according to claim 10 , wherein the pressure adjustment shaft gear has a smaller thickness than the driving gear with respect to an axial direction of the pressure adjustment shaft.

Assignees

• Hitachi Industry Equipment Systems Co Ltd

Inventors

• Arima Takahiro
• Takagishi Tsuneaki
• Kato Manabu
• Yamaguchi Shoki
• Hasegawa Satoshi
• Okano Mamoru

Classifications

• B41J2/08 Primary

  charge-control type · CPC title

• B41J2/125

  Sensors, e.g. deflection sensors {(nozzle clogging detection for cleaning reasons B41J2/16579; detection for compensation for failed nozzles B41J2/2139)} · CPC title

• B41J2/085

  Charge means, e.g. electrodes · CPC title

• B41J2/18

  Ink recirculation systems · CPC title

• B41J2/17563 Primary

  Ink filters · CPC title