IP Library Granted Patent US 10,331,056
Granted Patent B2
US 10,331,056 · App. 15/747,985 · Granted Jun 25, 2019

Charging elements in electrophotographic printers

Inventors: Asaf Anufa (Ness Ziona, IL); Shmuel Borenstain (Ness Ziona, IL); Maty Verner (Ness Ziona, IL)
Assignee: HP Indigo B.V.
G03G15/0266G03G15/10G03G15/104G03G15/169G03G21/06
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Quick Facts
Patent No.
US 10,331,056
App. No.
15/747,985
Granted
Jun 25, 2019
Kind
B2
Abstract

In certain examples, a liquid electrophotographic printer has a charge erasing element and a charging element. The charge erasing element at least partially discharges a charged photo imaging plate and a charged layer of liquid toner and the charging element at least partially recharges the layer of liquid toner and the photo imaging plate.

Claims (39)

1. A liquid electrophotographic printer comprising:

a photo imaging plate;

a first charging element to charge the photo imaging plate;

at least one image development unit to develop a latent image by depositing a charged layer of liquid toner onto the charged photo imaging plate;

a charge erasing element to at least partially discharge the charged photo imaging plate and the charged layer of liquid toner; and

a second charging element to at least partially recharge the layer of liquid toner and the photo imaging plates;

an intermediate transfer member, wherein the intermediate transfer member is grounded, and wherein the grounded intermediate transfer member receives the at least partially recharged layer of liquid toner from the at least partially recharged photo imaging plate and transfers the at least partially recharged layer of liquid toner to a print substrate.

2. The liquid electrophotographic printer of claim 1 , wherein a voltage is applied to the second charging element, and

wherein the applied voltage is tuned to adjust the recharging of the layer of liquid toner and photo imaging plate.

3. The liquid electrophotographic printer of claim 2 , wherein the applied voltage is the same polarity as the charged layer of liquid toner.

4. The liquid electrophotographic printer of claim 2 , wherein the applied voltage is tuned to enable substantially all of the at least partially recharged layer of liquid toner to be transferred to an intermediate transfer member.

5. The liquid electrophotographic printer of claim 2 , wherein the applied voltage is tuned to enable substantially all of the charge on the at least partially recharged photo imaging plate to be retained on the photo imaging plate.

6. The liquid electrophotographic printer of claim 1 , wherein the intermediate transfer member is grounded when the intermediate transfer member receives the at least partially recharged layer of liquid toner from the at least partially recharged photo imaging plate.

7. The liquid electrophotographic printer of claim 1 , wherein the intermediate transfer member is grounded when the intermediate transfer member transfers the at least partially recharged layer of liquid toner to the print substrate.

8. The liquid electrophotographic printer of claim 1 , wherein the print substrate is conductive.

9. The liquid electrophotographic printer of claim 1 , wherein the print substrate is non-conductive.

10. A method of printing an image in a liquid electrophotographic printer, the method comprising:

at least partially discharging a charged photo imaging plate and a charged layer of liquid toner applied on the charged photo imaging plate;

at least partially recharging the layer of liquid toner and the photo imaging plate;

transferring the at least partially recharged layer of liquid toner from the at least partially recharged photo imaging plate to an intermediate transfer member, wherein the intermediate transfer member is grounded; and

transferring the at least partially recharged layer of liquid toner from the grounded intermediate transfer member to a print substrate.

11. The method of claim 10 further comprising:

applying a voltage to a charging element and;

tuning the applied voltage to adjust the recharging of the layer of liquid toner and photo imaging plate.

12. The method of claim 11 further comprising:

tuning the applied voltage to enable at least one of:

substantially all of the at least partially recharged layer of liquid toner to be transferred to the grounded intermediate transfer member; and

substantially all of the charge on the at least partially recharged photo imaging plate to be retained on the photo imaging plate.

13. The method of claim 10 further comprising:

applying a voltage to a charging element, wherein the voltage is the same polarity as the charged layer of liquid toner.

14. A non-transitory computer readable storage medium comprising a set of computer-readable instructions stored thereon, which, when executed by a processor, cause the processor to, in a liquid electrophotographic printer;

apply a first voltage to a first charging element to charge a photo imaging plate;

control a charge erasing element to at least partially discharge the charged photo imaging plate and to at least partially discharge a charged layer of liquid toner on the charged photo imaging plate;

apply a second voltage to a second charging element to at least partially recharge the layer of liquid toner and the photo imaging plate;

control an intermediate transfer member to receive the at least partially recharged layer of liquid toner from the at least partially recharged photo imaging plate; and

control the intermediate transfer member to transfer the at least partially recharged layer of liquid toner to a print substrate;

wherein the processor grounds the intermediate transfer member:

when the intermediate transfer member receives the at least partially recharged layer of liquid toner from the at least partially recharged photo imaging plate; and

when the intermediate transfer member transfers the at least partially recharged layer of liquid toner to the print substrate.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 12, 2018
From: ANUFA, ASAF; VERNER, MATY; BORENSTAIN, SHMUEL
To: HEWLETT-PACKARD INDIGO B.V.
Reel/Frame 045519/0585 →
CHANGE OF NAME Recorded Apr 12, 2018
From: HEWLETT-PACKARD INDIGO B.V.
To: HP INDIGO B.V.
Reel/Frame 045922/0043 →
Continuity (1)
Related Publication 20180217519A1 · Aug 2, 2018