LIQUID METAL EJECTOR LEVEL SENSING SYSTEM AND METHODS THEREOF

1 . A method of controlling sensing level in a liquid ejector, comprising:

filling a reservoir in communication with a liquid ejector with a printing material;

reading a level signal from a surface of a melt pool in the reservoir using a sensor;

coupling the level signal to the filling of the reservoir with the printing material;

receiving a drop out signal from the sensor;

pausing a jetting operation of the liquid ejector;

increasing a quantity of printing material in the reservoir until the drop out signal is no longer received from the sensor; and

resuming the jetting operation of the liquid ejector.

2 . The method of controlling sensing level in a liquid ejector of claim 1 , wherein the printing material comprises a wire feed.

3 . The method of controlling sensing level in a liquid ejector of claim 2 , further comprising removing the printing material feed from the reservoir.

4 . The method of controlling sensing level in a liquid ejector of claim 1 , further comprising uncoupling the level signal from the filling of the reservoir with the printing material prior to increasing the quantity of printing material in the reservoir.

5 . The method of controlling sensing level in a liquid ejector of claim 1 , further comprising coupling the level signal to the filling of the reservoir with the printing material prior to resuming the jetting operation of the liquid ejector.

6 . The method of controlling sensing level in a liquid ejector of claim 1 , wherein the drop out signal comprises an erroneous signal from a laser-based level sensor reading scattering of light caused by contamination on the surface of the melt pool in the reservoir.

7 . The method of controlling sensing level in a liquid ejector of claim 1 , wherein the printing material comprises metal, metallic alloys, or a combination thereof.

8 . The method of controlling sensing level in a liquid ejector of claim 1 , wherein the printing material comprises aluminum, aluminum alloys, or a combination thereof.

9 . The method of controlling sensing level in a liquid ejector of claim 1 , wherein the printing material is a powder.

10 . The method of controlling sensing level in a liquid ejector of claim 1 , further comprising determining a maximum melt pool height prior to filling the reservoir with a printing material to a first level set point.

11 . The method of controlling sensing level in a liquid ejector of claim 10 , further comprising confirming an absence of a drop out signal from a laser-based level sensor after filling the reservoir with a printing material to a second level set point.

12 . The method of controlling sensing level in a liquid ejector of claim 11 , wherein the maximum melt pool height is higher than the first level set point and the second level set point.

13 . The method of controlling sensing level in a liquid ejector of claim 12 , wherein the first level set point is from about 4 mm to about 8 mm lower than the maximum melt pool height.

14 . The method of controlling sensing level in a liquid ejector of claim 11 , wherein the second level set point comprises from about 2 mm to about 4 mm relative to the first level set point.

15 . The method of controlling sensing level in a liquid ejector of claim 11 , further comprising:

adjusting the printing material level set point to a third level set point of printing material in reservoir that is higher than the second level set point; and

increasing the quantity of printing material in the reservoir to fill the reservoir to the third level set point.

16 . The method of controlling sensing level in a liquid ejector of claim 1 , further comprising repeating any of the steps of:

filling a reservoir in communication with a liquid ejector with a printing material;

reading a level signal from a surface of a melt pool in the reservoir using a sensor;

coupling the level signal to the filling of the reservoir with the printing material;

receiving a drop out signal from the sensor;

pausing a jetting operation of the liquid ejector;

increasing a quantity of printing material in the reservoir until the drop out signal is no longer received from the sensor; and

resuming the jetting operation of the liquid ejector.

17 . A method of controlling sensing level in a liquid ejector, comprising:

filling a reservoir in communication with a liquid ejector with a printing material to a first level set point;

receiving a drop out signal from a laser-based level sensor that reads from a surface of a melt pool in the reservoir;

pausing an operation of the liquid ejector;

adjusting the printing material level set point to a second level set point of printing material in reservoir that is higher than the first level set point;

increasing a quantity of printing material in the reservoir to fill the reservoir to the second level set point;

confirming an absence of the drop out signal from the laser-based level sensor after filling the reservoir with the printing material to the second level set point; and

resuming the operation of the liquid ejector; and

wherein the drop out signal comprises an erroneous signal from the laser-based level sensor reading scattering of light caused by contamination on the surface of the melt pool in the reservoir.

18 . The method of controlling sensing level in a liquid ejector of claim 17 , further comprising determining a maximum melt pool height prior to filling the reservoir with a printing material to a first level set point.

19 . The method of controlling sensing level in a liquid ejector of claim 18 , wherein the maximum melt pool height is higher than the first level set point and the second level set point.

20 . A method of controlling sensing level in a liquid ejector, comprising:

filling a reservoir in communication with a liquid ejector with a printing material;

reading a level signal from a surface of a melt pool in the reservoir using a sensor;

coupling the level signal to the filling of the reservoir with the printing material;

receiving a drop out signal from the sensor;

pausing a jetting operation of the liquid ejector;

increasing a quantity of printing material in the reservoir until the drop out signal is no longer received from the sensor;

resuming the jetting operation of the liquid ejector; and

repeating any of the preceding steps.