This invention relates to ink jets and more particularly to methods and apparatus of ejecting droplets of ink for purposes of marking.
A variety of ink jets are known in the art. Typically, an ink jet comprises a chamber which communicates with a supply of ink and an orifice coupled to the chamber through which droplets of ink are ejected. In a demand ink jet device, sometimes known as an impulse ink jet, the volume of the chamber is varied in response to the state of energization of a transducer with the resulting ejection of droplets from the orifice. Typically, the tranducer communicates with a wall of the chamber which is deformable in response to energization of the transducer thereby achieving the change of volume of the chamber.
In the typical ink jet device, the deformable wall does not progressively deform along a length thereof. In other words, there is no wave-like propagation of the deformation along the wall such as that known as peristaltic motion.
Peristaltic motion deformation is, of course, known, e.g., peristaltic motion is relied upon in the digestive system of mammals. Moreover, peristaltic pumping action has been relied upon as disclosed in U.S. Pat. No. 4,115,036 Patterson. Copending application Ser. No. 203,584, filed Nov. 3, 1980 and Ser. No. 203,589 filed Nov. 3, 1980 disclose the use of peristaltic pumping in connection with a supply of ink to an ink jet chamber. However, these patent applications do not disclose ink jet chambers themselves which create a peristaltic wave-like motion for purposes of ejecting a droplet of ink.