Liquid electrophotographic toner applicator
AssigneeCoulter Systems Corporation
InventorJosef Matkan
Life of this patent
Estimating the term…
Abstract
An applicator and method for applying liquid dispersed toner to the surface of an electrographic recording member, held on a platen which moves over a planar developing electrode, in which there is relative movement between the developing electrode and the recording member alternately in opposite direction, and in which there are at least two coplanar developing electrodes having toner fed therebetween, such as by a roller, and in which there are control means such as varying the direction of rotation of the roller to cause the developer to flow over either one or other of the developer electrodes according to the direction of relative movement of the platen.
Claims15
The method for the application of liquid dispersed toner to the surface of an electrographic recording member consisting in the steps of
- (a) positioning said electrographic recording member on a flat platen support member arranged for relative movement over at least a pair of spaced-apart coplanar developing electrodes which form with the said platen member a developer gap
- (b) providing a flow of liquid dispersed toner to the space between the two said spaced-apart developing electrodes and directing the flow of the said toner outwards over either the one or the other said developing electrodes to flow through the said developer gap and
- (c) alternately changing the direction of flow of the said toner in the said developer gap while changing the relative direction of movement of the said platen member in relation to the said developer electrodes.
The method of toning a recording member having a recording surface carrying an electrostatic latent charge image and comprising the steps of
- holding the recording member on a flat platen with the recording surface facing outward,
- providing at least a pair of laterally spaced coplanar developing electrodes having coplanar surfaces spaced parallel to the recording surface defining a toning gap between said recording surface and the said electrodes,
- effecting relative parallel movement of one of said platen and said electrodes selectively in opposite directions,
- feeding toner to at least one of said coplanar surfaces during said relative movement,
- positioning toner feed roller means communicating to a toner container with a portion of the circumferential surface thereof between said spaced planar surfaces with the top portion of said feed roller means proximate the level of said coplanar surfaces,
- slidably moving said toner feed roller means in the same direction of travel as the movable one of said platen and electrodes,
- establishing a predetermined minimal spacing between said roller means and said movable one so that toner is fed to the planar surface which is positioned leading in the direction of movement taken by the movable one during movement and to the other one of said coplanar surfaces during reverse movement and
- reversing the direction of rotation of the toner feed roller with change in the relative direction of said movement.
Means for the application of liquid dispersed toner to the surface of an electrographic recording member comprising a platen support member for an electrographic recording member and developing electrode means spaced form the said platen member to form a toning gap,
- characterised in that at least a pair of spaced-apart coplanar developing electrodes are used spaced from and generally parallel to the platen member to form between the platen member and the electrodes the said toning gap, the platen member and electrodes being mounted to have relative movement therebetween in the plane of the said developing electrodes,
- further characterised by liquid toner supply means between the developing electrodes arranged to selectively flow toner outwards over the one or the other of the developing electrodes according to the direction of relative movement between the said platen member and the said electrode.
A toning device for an electrostatic latent image carried by a recording member surface, comprising a liquid toner container opening to the recording surface,
- at least a pair of laterally spaced coplanar development electrodes proximate the opening of said container facing the recording surface and spaced therefrom to define a toning gap therebetween,
- liquid toner feed rollers means disposed between said electrodes and in communication with the toner in said container,
- means mounting said toner feed roller means for rotation within said container,
- means for moving one of the recording surface and electrode pair horizontally relative the other in a first direction with the toner feed roller being rotatable in said first direction and reversing the direction of movement from the first direction to a second direction,
- means mounting said toner feed roller means for limited horizontal slidable movement from a first position closely proximate one electrode during said movement in said first direction and a second position closely proximate the other electrode during said reverse movement, and
- the direction of rotation of the toner feed roller means being the same as the direction of horizontal movement of the movable one of said recording member and electrodes.
Dependencies are inferred from the claim text.