Printing using a metal-surface charging element

Patent metadata

Field	Value
Publication number	US-9618869-B2
Application number	US-201214379310-A
Country	US
Kind code	B2
Filing date	Apr 30, 2012
Priority date	Apr 30, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

Techniques related to printing using a metal-surface charging element. A printing system includes a metal-surface charging element and a power supply. The charging element is disposed to deposit electric charge on an imaging surface. The power supply may provide electric power with an alternating current (AC) component and a direct current (DC) component to the charging element.

First claim

We claim:

1. A printing system comprising:
a charging element comprising an electrically-conducting metal surface to deposit electric charge on an imaging surface during a printing operation of the printing system; and
at least one of a spring and a weight coupled to the charging element to exert a biasing force on the charging element to reduce a gravitational force that the charging element applies towards the imaging surface.

2. The printing system of claim 1 wherein the charging element comprises one of a hollow metal cylinder and a solid metal roller.

3. The printing system of claim 1 , further comprising a power supply to provide electric power with an alternating current (AC) component and a direct current (DC) component to the charging element.

4. The printing system of claim 3 wherein the AC component has amplitude between about 600 and 800 volts and a frequency between about 5 and 10 kHz.

5. The printing system of claim 3 wherein the DC component is between about −900 and −1,050 volts.

6. The printing system of claim 3 wherein the DC component has a magnitude between about 500 and 1,200 volts and the AC component has amplitude between about 500 and 1,000 volts and a frequency between about 2 kHz and 20 kHz.

7. The printing system of claim 1 and further comprising an imaging surface in physical contact with the charging element.

8. The printing system of claim 1 , further comprising the imaging surface disposed in charge-receiving relation to the charging element, rotationally coupled to the charging element, and spaced apart from the charging element by a gap.

9. The printing system of claim 1 , further comprising:
the imaging surface in charge-receiving relation to, and rotationally coupled to, the charging element;
a laser rotationally downstream from the charging element and aimed at the imaging surface;
a plurality of ink developer rollers rotationally downstream from the laser in ink-transfer relation to the imaging surface;
an intermediate transfer drum rotationally downstream from the charging element; and
an impression drum rotationally coupled to the intermediate transfer drum and defining with the intermediate transfer drum a paper flow path.

10. The printing system of claim 1 wherein the printing system comprises a liquid electrophotographic printer.

11. A method of printing with a metal-surface charging element comprising:
electrically charging an imaging surface by applying electric power to a metal-surface charging element in rotational and charge-transferring relation with the imaging surface;
using at least one of a spring and a weight to exert a biasing force on the metal-surface charging element to reduce a gravitational force that the metal-surface charging element applies towards the imaging surface;
forming a charge image on the electrically-charged imaging surface;
applying ink to the imaging surface to image the ink according to the charge image;
transferring the imaged ink to a transfer roller; and
transferring the imaged ink from the transfer roller to paper.

12. The method of claim 11 wherein the electric power includes an AC component with amplitude between about 500 and 1,000 volts and a frequency between about 2 and 20 kHz.

13. The method of claim 11 wherein the electric power includes a DC component with a potential between about 500 and 1,200 volts.

14. A method of manufacturing a printing system, the method comprising:
providing an imaging surface;
disposing a charging element including a metal surface adjacent and in charge-depositing relation with the imaging surface; and
using at least one of a spring and a weight to exert a biasing force on the charging element to reduce a gravitational force that the charging element applies towards the imaging surface.

15. The method of claim 14 , further comprising electrically coupling the charging element to a power supply to provide electric power with an alternating current (AC) component and a direct current (DC) component.

16. The method of claim 14 wherein the imaging surface is selected from the group comprising a drum carrying a photoconducting cover and a dielectric drum.

Assignees

• Lee Michael H
• Gila Omer
• Chang Seongsik
• Matheson Paul F
• Hewlett Packard Development Co Lp

Inventors

• Lee Michael H
• Gila Omer
• Chang Seongsik
• Matheson Paul F

Classifications

• G03G15/0233 Primary

  Structure, details of the charging member, e.g. chemical composition, surface properties · CPC title

• G03G15/0216 Primary

  by bringing a charging member into contact with the member to be charged, e.g. roller, brush chargers · CPC title