Method and apparatus for controlling the electric charge on droplets and ink-jet recorder incorporating the same
OwnerCarl H. Hertzinventor
Life of this patent
Estimating the term…
Abstract
Method and apparatus for controlling the electric charge on droplets formed by the breaking up of a pressurized liquid stream at a drop formation point located within an electric field. The field is provided to have an electric potential gradient and means are provided to effect drop formation at a point in the field corresponding to the desired predetermined charge to be placed on the droplets at the point of their formation. The location of the drop formation point within the charging field may be controlled by one or more signals applied to various components of the apparatus. The method and apparatus are particularly suited to ink-jet recording systems.
Claims57
A method of providing a stream of liquid droplets which carry thereon electric charges of predetermined magnitude and polarity, comprising the steps of
- (a) providing an electrically conductive liquid jet which breaks up at a drop formation point to form liquid droplets;
- (b) providing an electric field, through which said droplets are directed, having an electric potential gradient;
- and
- (c) controlling the location of said drop formation point within said electric field along said gradient thereby to control the electric charge on said droplets.
A method of ink-jet printing, comprising the steps of
- (a) forcing an electrically conductive liquid under pressure through a nozzle to form a jet of said liquid which breaks up into a jet of liquid droplets at a drop formation point;
- (b) directing said liquid jet through an electric field having an electric potential gradient;
- (c) controlling the location of said drop formation point within said electric field along said gradient thereby to place on said droplets electrical charges of predetermined polarity and magnitude;
- and
- (d) electrically controlling the direction of travel of the charged droplets whereby selected ones of said droplets are directed onto a receptor surface in a predetermined pattern.
A method of ink-jet printing, comprising the steps of
- (a) directing an electrically conductive liquid under pressure through a nozzle to form a jet of said liquid which breaks up into a jet of liquid droplets at a drop formation point;
- (b) directing said liquid jet through an electric field having an electric potential gradient along the path travelled by said liquid jet through said field;
- (c) controlling the location of said drop formation point within said electric field along said gradient, thereby to place on said droplets electrical charges of predetermined polarity and magnitude;
- and
- (d) electrically controlling the direction of travel of the charged droplets whereby selected ones of said droplets are directed onto a receptor surface in a predetermined pattern.
An apparatus for providing a stream of liquid droplets having predetermined electrical charges thereon, comprising, in combination
- (a) nozzle means;
- (b) means to eject a liquid jet under pressure from said nozzle means on a manner to break up said liquid jet into droplets at a drop formation point thereby to form a jet of liquid droplets;
- (c) droplet control electrode means arranged to define an electric field through which said liquid jet is directed and in which said drop formation point is located, said electric field having an electric potential gradient;
- (d) means to control the location of said drop formation point within said electric field along said gradient thereby to control the electric charge on said droplets.
An apparatus for ink-jet printing, comprising in combination
- (a) nozzle means;
- (b) means to define an electric droplet charging field having an electric potential gradient;
- (c) means to supply under pressure an electrically conductive liquid from a source through conduit means and through said nozzle thereby to form a liquid jet which travels through said electric field and which breaks up into liquid droplets at a drop formation point located within said electric field;
- (d) means to control the location of said drop formation point within said electric field along said gradient thereby to place on said droplets electrical charges of predetermined polarity and magnitude;
- (e) receptor surface means;
- and
- (f) droplet directing electrode means to control the direction of travel of said droplets whereby selected ones of said droplets are directed onto said receptor surfaces in a predetermined pattern.
Dependencies are inferred from the claim text.