Liquid droplet writing mechanism

In an arrangement for applying liquid droplets to a surface, comprising a liquid applying unit including a chamber having an intake channel connected to a liquid supply container and a discharge channel through which the liquid is discharged from the chamber into the atmosphere, means for producing short duration pressure increases in the liquid in the chamber, the chamber having means dividing the chamber into an outer chamber portion adjacent to the discharge channel and an inner chamber portion, a connecting channel in the dividing means connecting the outer and inner chamber portions, the connecting channel being axially aligned with the discharge channel and the intake channel being communicated with the outer chamber portion, the inner chamber portion having a larger diameter portion in contact with the pressure producing means and a smaller diameter portion adjacent to the connecting channel, the improvement comprising:

• an intermediate reservoir chamber communicated with said outer chamber portion and with said intake channel;
• and
• the ratio of the diameter of said larger diameter portion to the distance between the outer end of said discharge channel and said pressure producing means ranges from 0.15 to 1.0 inclusive,
• whereby the liquid discharged through said discharge channel is replenished with the liquid in said intermediate reservoir chamber to enable the liquid in said outer chamber portion to respond to the rapid variations of said short duration pressure increases.