Image recording apparatus

1. An image recording apparatus comprising:

a liquid chamber which stores liquid used for recording of an image;

a first electrode pin and a second electrode pin which are inserted into the liquid chamber;

application unit for applying a voltage between the first electrode pin and the second electrode pin; and

detection unit for detecting a current which flows between the first electrode pin and the second electrode pin,

wherein the image recording apparatus has

a first period in which the application unit applies the voltage between the first electrode pin and the second electrode pin, with the first electrode pin being used as an anode side and the second electrode pin being used as a cathode side, and the detection unit detects the current, and

a second period in which the application unit applies the voltage between the first electrode pin and the second electrode pin, with the first electrode pin being used as the cathode side and the second electrode pin being used as the anode side.

2. The image recording apparatus according to claim 1 , further comprising:

a liquid ejection cartridge unit; and

a liquid supply tube which supplies the liquid from the liquid chamber to the liquid ejection cartridge unit.

3. The image recording apparatus according to claim 1 , further comprising:

a liquid tank;

a liquid ejection cartridge unit which has a recording element substrate and a sub-tank; and

a liquid supply tube which supplies the liquid from the liquid tank to the sub-tank,

wherein the liquid chamber is a liquid chamber of the sub-tank, and supplies the liquid supplied from the liquid supply tube to the recording element substrate.

4. The image recording apparatus according to claim 1 , further comprising:

a liquid tank; and

a liquid ejection cartridge unit which has a recording element substrate and a sub-tank connected to the liquid tank,

wherein the liquid chamber is a liquid chamber of the sub-tank, and temporarily retains the liquid supplied from the liquid tank and supplies the liquid to the recording element substrate.

5. The image recording apparatus according to claim 1 ,

wherein a difference between a length of an application accumulated time of the voltage applied in the first period and a length of an application accumulated time of the voltage applied in the second period falls within ±10% of the length of the application accumulated time of the voltage applied in the first period.

6. The image recording apparatus according to claim 1 ,

wherein an application accumulated time of the voltage applied in the second period is longer than an application accumulated time of the voltage applied in the first period.

7. The image recording apparatus according to claim 1 ,

wherein a pulse width of the voltage applied in the second period is longer than a pulse width of the voltage applied in the first period.

8. The image recording apparatus according to claim 1 ,

wherein an absolute value of the voltage applied in the second period is greater than an absolute value of the voltage applied in the first period.

9. The image recording apparatus according to claim 1 ,

wherein the first period is provided in plurality during a predetermined detection period for detecting a remaining amount of the liquid in the liquid chamber, and the second period is provided in plurality during a non-detection period different from the detection period.

10. The image recording apparatus according to claim 9 ,

wherein the plurality of the second periods are provided successively during the non-detection period.

11. The image recording apparatus according to claim 1 ,

wherein the liquid is an ink which uses self-dispersion type carbon black.

12. An image recording apparatus comprising:

a liquid chamber which stores liquid used for recording of an image;

a first electrode pin and a second electrode pin which are inserted into the liquid chamber;

application unit for applying a voltage between the first electrode pin and the second electrode pin; and

detection unit for detecting a current which flows between the first electrode pin and the second electrode pin,

wherein the image recording apparatus has

a first period in which the application unit applies the voltage between the first electrode pin and the second electrode pin, with the first electrode pin being used as an anode side and the second electrode pin being used as a cathode side, and the detection unit detects the current, and

a third period in which the application unit applies the voltage between the first electrode pin and the second electrode pin, with the first electrode pin being used as the cathode side and the second electrode pin being used as the anode side, and the detection unit detects the current.

13. The image recording apparatus according to claim 12 ,

wherein the image recording apparatus further has

a second period in which the application unit applies the voltage between the first electrode pin and the second electrode pin, with the first electrode pin being used as the cathode side and the second electrode pin being used as the anode side, and

a fourth period in which the application unit applies the voltage between the first electrode pin and the second electrode pin, with the first electrode pin being used as the anode side and the second electrode pin being used as the cathode side.