Browse Prior Art Database

Air Supply for Aspirated Ink Jet Printers

IP.com Disclosure Number: IPCOM000052738D
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 3 page(s) / 49K

Publishing Venue

IBM

Related People

Hendriks, F: AUTHOR [+4]

Abstract

Described is a small, self-contained air supply system suitable for aspirated ink jet printers. The system comprises a blower, compliant plenum, flow sensor and smoothing screens, is designed to supply a regulated source of air at a predetermined flow rate and at a predetermined pressure. Volumetric regulation from a nominal flow rate may be easily supplied by way of digital control.

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Air Supply for Aspirated Ink Jet Printers

Described is a small, self-contained air supply system suitable for aspirated ink jet printers. The system comprises a blower, compliant plenum, flow sensor and smoothing screens, is designed to supply a regulated source of air at a predetermined flow rate and at a predetermined pressure. Volumetric regulation from a nominal flow rate may be easily supplied by way of digital control.

An aspirated ink jet printer employs a small air tunnel 11 within a aspirator body 10 that couples to an ink jet head (not shown), the tunnel surrounding the ink drop trajectory 12 during the deflection phase. (Shown in outline or in dotted form are deflection electrodes 13 and 14 which are embedded within the tunnel for effecting deflection of charged ink droplets.) The ink and air velocities are preferably closely matched to reduce the relative air velocity as seen by the drop. Consequently, aerodynamic drag is greatly reduced. Without large drag forces, drops lose little kinetic energy, have long stable trajectories, and experience improved electrostatic deflection for a given charge-to-mass ratio. In addition, drop wakes are minimized and no guard drops are necessary to reduce drop-to- drop interactions. However, this simplification in drop placement incurs other complexities. One of the additional requirements is a source of air to drive the aspirator as well as some means of controlling its operating point.

The primary motivator in the air system is a small regenerative blower 15 mounted within the housing 16 which forms part of the carrier for holding the head as well as the aspirator for movement, in the present instance into and out of the plane of the paper. The blower is preferably driven by a DC servo motor to obtain optimum performance of a single stage turbo machine and to permit proper regulation and obt...