Electrophotographic member, process cartridge and electrophotographic image forming apparatus
US-2015331340-A1 · Nov 19, 2015 · US
Liquid electrophotographic ink developer unit
US10514633B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-10514633-B2 |
| Application number | US-201615773962-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jan 27, 2016 |
| Priority date | Jan 27, 2016 |
| Publication date | Dec 24, 2019 |
| Grant date | Dec 24, 2019 |
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- Title
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- Abstract
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- First independent claim
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Abstract
Official abstract text for this publication.
The present disclosure relates to a liquid electrophotographic ink developer unit. The unit comprises a developer roller, and a secondary roller that co-operates with the developer roller. The developer roller is formed of a material having a specific resistivity of less than 1×106 Ω·cm. The secondary roller is formed of a material having a specific resistivity of 1×104 to 1×109 Ω·cm.
First claim
Opening claim text (preview).
The invention claimed is: 1. A liquid electrophotographic ink developer unit, said unit comprising: a developer roller, and a secondary roller that co-operates with the developer roller, wherein the developer roller is formed of a material having a specific resistivity of less than 1×10 6 Ω·cm, and wherein the secondary roller comprises an outer coating formed of a ceramic material having a specific resistivity of 1×10 4 to 1×10 9 Ω·cm, wherein the outer coating has a thickness of 20 μm to 2 mm. 2. The unit as claimed in claim 1 , wherein the developer roller is formed from a material having a specific resistivity of 1×10 3 to 1×10 5 Ω·cm. 3. The unit as claimed in claim 1 , which comprises two of the secondary rollers. 4. The unit as claimed in claim 1 , wherein the developer roller comprises a polymer composition comprising a conductive filler dispersed in a polymer resin matrix, wherein the polymer composition has a specific resistivity of less than 1×10 6 Ω·cm. 5. The unit as claimed in claim 4 , wherein the conductive filler is selected from carbon nanotubes, graphene, carbon fibre, carbon black, metal particles, conductive oxide particles and intrinsic conductive polymer (ICP) particles. 6. The unit as claimed in claim 5 , wherein the conductive filler is carbon black and the concentration of carbon black in the polymer composition is 0.1 to 20% in weight. 7. The unit as claimed in claim 1 , wherein the ceramic material has a specific resistivity of 1×10 5 to 5×10 8 Ω·cm. 8. The unit as claimed in claim 1 , wherein the secondary roller comprises a metal core that is coated with said outer coating. 9. The unit as claimed in claim 8 , wherein the outer coating is formed of alumina-titania. 10. The unit as claimed in claim 1 , wherein the nip resistance between the developer roller and the secondary roller is 3×10 2 Ohm to 3×10 5 Ohm. 11. The unit as claimed in claim 1 , wherein the developer roller is formed of a material having a specific resistivity of less than 1×10 3 Ω·cm. 12. The unit as claimed in claim 1 , wherein the developer roller comprises a polymer composition having a specific resistivity of less than 1×10 6 Ω·cm and having a Shore A hardness of 20 to 70. 13. The unit as claimed in claim 1 , wherein the ceramic material is selected from the group consisting of aluminum oxide, titanium oxide, zirconium oxide, chromium oxide, yttrium oxide, hafnium oxide, and mixtures thereof. 14. A liquid electrophotographic printer, comprising: a developer roller, and a secondary roller that co-operates with the developer roller, wherein the developer roller is formed of a material having a specific resistivity of less than 1×10 6 Ω·cm, and wherein the secondary roller consists of a ceramic material having a specific resistivity of 1×10 4 to 1×10 9 Ω·cm, wherein the ceramic material is selected from the group consisting of aluminum oxide, titanium oxide, zirconium oxide, chromium oxide, yttrium oxide, hafnium oxide, and mixtures thereof.
Assignees
Inventors
Classifications
characterised by the structure of the donor member, e.g. surface properties · CPC title
Structure, details of the charging member, e.g. chemical composition, surface properties · CPC title
Particular composition or materials · CPC title
- G03G15/10Primary
using a liquid developer · CPC title
Polyurethanes · CPC title
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Frequently asked questions
Answers are generated from the same data shown on this page.
- What does patent US10514633B2 cover?
- The present disclosure relates to a liquid electrophotographic ink developer unit. The unit comprises a developer roller, and a secondary roller that co-operates with the developer roller. The developer roller is formed of a material having a specific resistivity of less than 1×106 Ω·cm. The secondary roller is formed of a material having a specific resistivity of 1×104 to 1×109 Ω·cm.
- Who is the assignee on this patent?
- Hewlett Packard Development Co
- What technology area does this patent fall under?
- Primary CPC classification G03G15/10. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue Dec 24 2019 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 3 related publications on this page (citations in our corpus or others sharing the same primary CPC).