# US 2018/0129151 A1 · Electrophotographic printers

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2018/0129151 A1
- Document ID: US20180129151A1
- Status: Published application
- Kind: A1
- Application number: 15/569,319
- Filed: 2015-07-28
- Published: 2018-05-10
- Earliest claimed: 2015-07-28
- Assignees: HP Indigo B.V.
- Applicants: HP Indigo B.V.
- Inventors: Peter Nedelin; Mark Sandler; Shai Lior
- Web page: https://patentgrep.com/patent/US20180129151A1

## CPC

- G03G 15/10: using a liquid developer
- G03G 15/11: Removing excess liquid developer, e.g. by heat
- G03G 15/14: for transferring a pattern to a second base
- G03G 15/161: {with means for handling the intermediate support, e.g. heating, cleaning, coating with a transfer agent}
- G03G 15/201: {of high intensity and short duration, i.e. flash fusing}
- G03G 2215/025: using contact charging means having lateral dimensions related to other apparatus means, e.g. photodrum, developing roller
- G03G 2215/027: using wires
- G03G 2215/0631: melted, or otherwise made liquid
- G03G 2215/16: Transferring device, details
- G03G 2215/1671: Preheating the copy medium before the transfer point
- G03G 2215/1685: using heat
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A method of operating an electrophotographic printer (100) to control the optical density of a printed image is described. The method comprises providing a printing substance on a transfer member (104); emitting a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and transferring, from the transfer member to a substrate (108), the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.

## Claims

### Claim 1

A method of operating an electrophotographic printer to control the optical density of a printed image, the method comprising:
providing a printing substance on a transfer member;
emitting a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and
transferring, from the transfer member to a substrate, the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the transfer member comprises a transfer blanket.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the printing substance is a liquid comprising particles suspended therein.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the pulse of heat has a power density of at least 0.1 W/mm2.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the emitting comprises emitting the pulse of heat to heat the printing substance within 0.1 seconds prior to the printing substance being transferred to the substrate.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the emitting comprises emitting the pulse of heat to heat the printing substance to create a uniform layer of the printing substance on the transfer member.

### Claim 7 (depends on 1)

The method according to claim 1, wherein a printing process speed of the electrophotographic printer is at least 1000 mm/s.

### Claim 8

An electrophotographic printer comprising:
a transfer element to transfer an image from the transfer element to a substrate; and
a heater to emit a pulse of heating energy to heat the image on the transfer element with a power density of at least 0.1 W/mm2.

### Claim 9 (depends on 8)

The electrophotographic printer according to claim 8, wherein the heater is to emit a pulse of heating energy to heat the image on the transfer element with a power density of at least 1.0 W/mm2.

### Claim 10 (depends on 8)

The electrophotographic printer according to claim 8, wherein the transfer element comprises a transfer cylinder and a transfer blanket surrounding the transfer cylinder, and wherein the heater is to emit the pulse of heating energy to heat the image on the transfer blanket substantially without heating the transfer cylinder.

### Claim 11 (depends on 8)

The electrophotographic printer according to claim 8, wherein the heater is to heat the image on the transfer member within 0.1 seconds prior to the image being transferred to the substrate.

### Claim 12 (depends on 8)

The electrophotographic printer according to claim 8, wherein the heater is to emit the pulse of heating energy for less than 0.5 seconds to heat the image on the transfer element.

### Claim 13

An electrophotographic printer to control the optical density of a printed image, the electrophotographic printer being to:
provide a printing substance on a transfer member;
emit a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and
transfer, from the transfer member to a substrate, the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.

### Claim 14 (depends on 13)

The electrophotographic printer according to claim 13, wherein the heater is to heat the printing substance on the transfer member to a temperature of greater than 140 degrees Celsius.

### Claim 15 (depends on 13)

The electrophotographic printer according to claim 13, wherein the electrophotographic printer is a liquid electrophotographic printer, and the transfer member comprises a transfer blanket to transfer the printing substance directly from the transfer blanket to the substrate.