Shaped charge generation layer for a photoconductive drum

Patent metadata

Field	Value
Publication number	US-11256185-B2
Application number	US-202016877783-A
Country	US
Kind code	B2
Filing date	May 19, 2020
Priority date	Oct 29, 2019
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

A photoconductive drum includes an elongated support element with a shaped charge generation layer. The layer extends from the support element at various thicknesses along a length thereof. Thicker charge generation portions provides denser optical densities compared to thinner portions allowing tailoring the photoconductive drum to compensate for imperfect optical scanning systems. A charge transport layer overcoats the charge generation layer. Optionally, an oxidation layer underlies the charge generation layer as does a protective overcoat overlying the charge transport layer. Various thicknesses and shapes of the charge generation layer are also disclosed.

First claim

The invention claimed is:

1. A photoconductive drum, comprising:
an elongated support element having a surface;
an oxidation layer on the surface;
a charge generation layer disposed over the oxidation layer, the charge generation layer having a uniform first thickness along about two-thirds of a length of the elongated support element ranging from about 0.2 to about 0.5 μm and, along about one-third of a remainder of the length of a distal or proximate end of the elongated support element, the charge generation layer having a uniform second thickness greater than the first thickness and being distinct from the first thickness by a transition in thickness from a middle one-third of the length of the elongated support element; and
a charge transport layer disposed over the charge generation layer.

2. The photoconductive drum of claim 1 , further including a protective overcoat over the charge transport layer.

3. The photoconductive drum of claim 1 , wherein the second thickness is about 0.1 μm thicker than the first thickness.

4. The photoconductive drum of claim 1 , wherein the elongated support element is substantially cylindrical about a longitudinal axis thereof.

5. The photoconductive drum of claim 1 , wherein the charge generation layer tapers symmetrically from the second thickness to the first thickness at the transition in thickness.

6. The photoconductive drum of claim 1 , wherein the elongated support element is a 3003 aluminum alloy.

7. The photoconductive drum of claim 1 , wherein the elongated support element is hollow with an inner and outer diameter being in a range of about 20 to about 25 mm and having said length in a range of about 245 to about 255 mm.

8. The photoconductive drum of claim 1 , wherein the oxidation layer is about 3 to about 5 μm.

9. The photoconductive drum of claim 1 , wherein the charge transport layer is about 17 to about 19 μm.

10. The photoconductive drum of claim 1 , wherein an active ingredient of the charge generation layer is titanyl phthalocyanine.

11. A photoconductive drum, comprising:
a substantially cylindrical elongated support element having a length and being an aluminum alloy;
a charge generation layer disposed over the elongated support element, the charge generation layer having a uniform first thickness along about two-thirds of the length of the elongated support element ranging from about 0.2 to about 0.5 μm and, along about one-third of a remainder of said length of the elongated support element, the charge generation layer having a uniform second thickness greater than the first thickness by about 0.1 μm and being distinct from the first thickness by a transition in thickness from a middle one-third of the length of the elongated support element; and
a charge transport layer disposed over the charge generation layer.

12. The photoconductive drum of claim 11 , further including an oxidation layer on a surface of the elongated support element.

13. The photoconductive drum of claim 11 , wherein about 2 mm of the elongated support element is uncoated with the charge generation layer.

14. The photoconductive drum of claim 11 , wherein the elongated support element is hollow with an inner and outer diameter being in a range of about 20 to about 25 mm and having said length in a range of about 245 to about 255 mm.

15. The photoconductive drum of claim 11 , wherein the charge transport layer extends in thickness about the elongated support element in a range of about 17 to about 19 μm.

16. The photoconductive drum of claim 11 , wherein the charge generation layer is polyvinylbutyral.

Assignees

• Lexmark Int Inc

Inventors

• Heid Matthew David
• Kierstein Laura Lee
• Luo Weimei
• Shrestha Prasanna

Classifications

• G03G5/144

  comprising inorganic material · CPC title

• G03G5/047

  characterised by the charge-generation layers or charge transport layers {(G03G5/0433 and G03G5/0436 take precedence)} · CPC title

• G03G5/102

  consisting of or comprising metals · CPC title

• G03G5/0696

  Phthalocyanines · CPC title

• G03G5/147

  Cover layers · CPC title