Patent ID: 8770722

Claim:
A liquid dispenser comprising: a first liquid supply channel; a liquid dispensing channel including an outlet opening; a liquid return channel; a first liquid supply that provides a carrier liquid under pressure that flows from the first liquid supply through the first liquid supply channel through the liquid dispensing channel through the liquid return channel and back to the first liquid supply continuously during a drop dispensing operation; a second liquid supply channel; a second liquid supply that provides a functional liquid to the liquid dispensing channel through the second liquid supply channel; a drop formation device associated with an interface of the second liquid supply channel and the liquid dispensing channel, the drop formation device being selectively actuated to form a discrete drop of the functional liquid in the carrier liquid flowing through the liquid dispensing channel, the functional liquid being immiscible in the carrier liquid; and a drop ejection device that is selectively actuated to divert the discrete drop of the functional liquid and a portion of the carrier liquid flowing through the liquid dispensing channel toward the outlet opening of the liquid dispensing channel.