Method of toner transfer with pulse bias
AssigneeCoulter Systems Corporation
InventorPhillip E. Staples
Life of this patent
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Abstract
A method of electrically transferring an image deposit formed of liquid dispersed electroscopic toner particles from an image-bearing photoconductor surface of a recording member to the surface of an image-receiving member in which an electrical transfer bias voltage is applied through the interface between the said surfaces in a direction normal to the said surfaces, and in which the said electrical transfer bias voltage is applied intermittently by successive pulses of opposite polarity and with successively increasing voltage, with the final pulse of an electrical polarity and magnitude to transfer the said imaging material to the said receiving member.
Claims13
A method of electrically transferring an image deposit formed from a liquid developer comprising electroscopic toner particles dispersed in an electrically insulating carrier liquid, from a smooth image-bearing photoconductor surface of a recording member to a smooth surface of an image-receiving member having a non-conductive side and in which the image-bearing surface of the recording member is placed into contact with the image-receiving surface of the non-conductive side of the said image-receiving member, the image-recording and image-receiving members being impervious to the carrier liquid of the liquid developer and an electrical transfer bias voltage is applied through the interface between the said surfaces in a direction normal to the said surfaces, characterised in that the said electrical transfer bias voltage is applied intermittently by successive pulses of opposite polarity and with successively increasing voltage gradually progressively to remove excess liquid from the interfaced surfaces, while the final pulse being of an electrical polarity and magnitude sufficient to transfer the said image deposit to the said receiving member.
A method of electrostatically transferring an image deposit formed of electroscopic toner particles from a liquid developer comprising electroscopic toner particles dispersed in an electrically insulating carrier liquid from the image-bearing smooth photoconductor surface of a recording member to the smooth surface of a receiving member while removing excess liquid developer therebetween, the recording and receiving members being impervious to the carrier liquid, said method comprising the steps of:
- (A) providing a receiving member having a non-conductive side and an electrically conductive thin coating on a surface thereof,
- (B) positioning one of the recording and receiving members on a conductive surface base,
- (C) effecting a physical interface between the nonconductive side of said receiving member and said recording member with the conductive coating of said receiving member spaced from said interface,
- (D) applying a first bias voltage across said interface, selecting said bias voltage to be of value and polarity to effect movement of said receiving member toward the recording member,
- (E) applying a second bias voltage across said interface with said second bias voltage being at least of the value of said first bias voltage but of opposite polarity relative thereto,
- (F) repeating said first and second bias voltage applications for at least an additional cycle but at an increased voltage value, to bring said image-bearing and receiving members progressively closer to effect removal of excess liquid developer therebetween,
- (G) the final application of bias voltage being of a polarity and magnitude sufficient to transfer the image deposit to said receiving member and
- (H) separating said receiving and recording members, there being complete image transfer across said interface from said recording member to said receiving member in the absence of lateral displacement of the toner particles.
Dependencies are inferred from the claim text.