Patent · US Expired

Droplet ejecting head, method for driving the same, and droplet ejecting apparatus

US6851778B2 · kind B2 · utility

4Cited by
1References
17Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 3, 2002
Grant dateFeb 8, 2005
Priority date
Expiry dateAug 1, 2023

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB41J2/04588
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A nozzle for ejecting a droplet has a straight portion having a substantially straight shape. A driving waveform to be applied to a piezoelectric actuator includes a first voltage change process for expanding volume of a pressure generating chamber to retract a meniscus of the nozzle portion toward the pressure generating chamber and a second voltage change process for compressing the volume of the pressure generating chamber to eject a droplet. Voltage change quantity and voltage change time of the first voltage change process are set so that meniscus retraction quantity D when the second voltage change process is applied satisfies 0.8·ln≦D≦1.5·ln (ln designates length of the straight portion of the nozzle). Consequently, when the second voltage change process is applied, strong liquid surface interference can be produced in the nozzle central portion. Therefore, a droplet having an extremely small droplet volume can be ejected.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.