Control method and apparatus for dispensing high-quality drops of high- viscosity material

An apparatus for rapidly dispensing minute quantities of a highly viscous material from a jetting orifice, comprising:

• a jetting chamber having sides, an open top, and a bottom having an opening that is in fluid communication with an exit orifice, the chamber being in fluid communication with an external fluid reservoir containing said material during use;
• a flexible diaphragm covering the open top of the jetting chamber, the diaphragm having a central protrusion extending toward the opening in the bottom of the chamber on one side of the diaphragm, the diaphragm being sufficiently flexible to deform into the jetting chamber a distance sufficient so that the central protrusion blocks the opening in the bottom of the chamber during use;
• an impact element having an impact end spaced apart from the central protrusion on the opposite side of the diaphragm as the opening in the bottom of the chamber and aligned therewith;
• a support structure having an opening aligned with the top of the jetting chamber, the opening configured to allow the impact element to impact the diaphragm to deform into the jetting chamber when the impact element is activated;
• and
• a sensing device configured to detect the distance between the impact element and the top of the diaphragm.

An apparatus for rapidly dispensing minute quantities of a highly viscous material from a jetting orifice, comprising:

• a jetting chamber having sides, an open top, and a bottom having an outlet opening that is in fluid communication with an exit orifice, the chamber being in fluid communication with an external fluid reservoir containing said material during use;
• a flexible diaphragm covering the top of the jetting chamber, the diaphragm having a central protrusion extending toward the outlet opening in the bottom of the chamber, the diaphragm being sufficiently flexible to deform into the jetting chamber a distance sufficient so that the central protrusion blocks the opening in the bottom of the chamber during use;
• an impact element having an impact end spaced apart from the central protrusion on the opposite side of the diaphragm as the outlet opening in the bottom of the chamber and aligned therewith;
• a support structure for the impact element and having a support structure opening aligned with the top of the jetting chamber, the support structure opening configured to allow the impact element to pass through the opening to impact the diaphragm to deform the diaphragm into the jetting chamber when the impact element is activated;
• and
• a sensing device configured to detect a velocity of drops ejected from an orifice downstream from the outlet.

A method of dispensing high-quality minute quantities of a viscous material from an outlet of a jetting orifice by an expelling mechanism that deforms a flexible diaphragm into a jetting chamber that is in fluid communication with the jetting orifice, with the diaphragm forming a portion of the jetting chamber, the method comprising:

• forcing a predetermined amount of the viscous fluid through an inlet channel and into the jetting chamber;
• moving an impact element through a predetermined distance;
• impacting the flexible diaphragm with the impact element;
• deforming the flexible diaphragm into the jetting chamber a distance sufficient to block the fluid flow into the orifice and expel material from the outlet;
• measuring the distance the impact element travels before contacting the diaphragm;
• and
• adjusting the predetermined distance the impact element moves to vary the force with which the impact element impacts the diaphragm.

A method of dispensing high-quality minute quantities of a viscous material from an outlet of a jetting orifice by an expelling mechanism that deforms a flexible diaphragm into a jetting chamber that is in fluid communication with the jetting orifice, the method comprising:

• forcing the viscous fluid into the jetting chamber through an inlet channel;
• deforming the flexible diaphragm into the jetting chamber a distance sufficient to block the fluid flow out the orifice;
• moving an impact element through a predetermined distance;
• impacting the flexible diaphragm with the impact element in order to eject the viscous material from the outlet;
• and;
• adjusting at least one of the predetermined distance or the velocity of the impact element to vary the force with which the impact element impacts the diaphragm.

A method of dispensing quality minute quantities of a viscous material from an outlet of a jetting orifice of a jetting chamber by an expelling mechanism, comprising:

• forcing a predetermined amount of the viscous fluid through an inlet channel and into the jetting chamber;
• moving an impact element through a predetermined distance;
• impacting the flexible diaphragm with the impact element at an impact velocity;
• deforming the flexible diaphragm into the jetting chamber a distance sufficient to block the fluid flow into the orifice and expel a drop of material from the outlet;
• measuring the velocity of the expelled drop;
• and
• adjusting the impact element to vary the momentum with which the impact element impacts the diaphragm.