# US 2024/0201614 A1 · Electrophotographic control in imaging devices, including sensing current between a developer roll and drum pertaining to current of a latent image and a paschen breakdown

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

- Number: US 2024/0201614 A1
- Document ID: US20240201614A1
- Status: Published application
- Kind: A1
- Application number: 18/092,368
- Filed: 2023-01-02
- Published: 2024-06-20
- Earliest claimed: 2022-12-14
- Assignees: Lexmark International, Inc.
- Applicants: Lexmark International, Inc.
- Inventors: MARC COUSOULIS; MICHAEL CHARLES DAY; KWEKU KORSAH; JARED KOUHUI LIN; DAVID WILLIAM SHUMAN; MATTHEW RUSSELL SMITHER
- Web page: https://patentgrep.com/patent/US20240201614A1

## CPC

- G03G 15/0808: {characterised by the developer supplying means, e.g. structure of developer supply roller}
- G03G 15/0266: {Arrangements for controlling the amount of charge}
- G03G 15/043: with means for controlling illumination or exposure (G03G15/041 takes precedence)
- G03G 15/5004: {Power supply control, e.g. power-saving mode, automatic power turn-off}
- G03G 2215/00632: Electric detector, e.g. of voltage or current
- G03G 2215/066: Toner cartridge or other attachable and detachable container for supplying developer material to replace the used material
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An imaging device has a developer roll to provide toner to a photoconductive drum to develop a latent image on the drum for direct transfer to media or an intermediate transfer member. A power supply in communication with a controller sets relative voltages on the developer roll and drum. During transfer of the toner, the imaging device determines a current between the developer roll and drum. In turn, the controller determines a charge and mass of the toner for setting with the power supply an operating voltage on the drum or developer roll. Preventing and reporting toners with insufficient charge are other embodiments.

## Claims

### Claim 1

In an imaging device having a photoconductive drum opposed by developer roll to provide toner to the drum to develop a latent image on the drum for transfer to media or an intermediate transfer member and later the media, further including a power supply in communication with a controller, a method comprising:
with the power supply, setting a first voltage on a charge roll that creates a second voltage on a surface of the drum;
based on the first and second voltages, transferring the toner from a developer roll to the drum; and
sensing a current between the developer roll and the drum, including determining a first current of the latent image and a second current of a Paschen breakdown between the developer roll and the drum.

### Claim 2 (depends on 1)

The method of claim 1, wherein the sensing the current occurs in the power supply.

### Claim 3 (depends on 1)

The method of claim 1, further including providing the current to the controller.

### Claim 4

(canceled)

### Claim 5

(canceled)

### Claim 6 (depends on 1)

The method of claim 1, further including storing the first and second currents in a memory accessible by the controller.

### Claim 7 (depends on 1)

The method of claim 1, further including, by the controller, subtracting from the current the first and second currents.

### Claim 8 (depends on 1)

The method of claim 1, further including determining a charge of the toner.

### Claim 9 (depends on 1)

The method of claim 1, further including determining a charge per mass of the toner.

### Claim 10 (depends on 1)

The method of claim 1, further including determining a mass of the toner.

### Claim 11 (depends on 1)

The method of claim 1, further including developing a toner patch on the intermediate transfer member.

### Claim 12 (depends on 11)

The method of claim 11, further including projecting a light on the toner patch and collecting the light scattered from the toner patch.

### Claim 13 (depends on 12)

The method of claim 12, further including determining a toner mass from the light scattered.

### Claim 14 (depends on 13)

The method of claim 13, further including using the sensed current and the determined toner mass of the toner patch to determine an operating condition of the toner.

### Claim 15 (depends on 1)

The method of claim 1, further including changing a third voltage on the developer roll or the drum based on the sensed current.

### Claim 16 (depends on 1)

The method of claim 1, further including providing a toner cartridge having said toner.

### Claim 17

In an imaging device having a photoconductive drum opposed by developer roll to provide toner to the drum to develop a latent image on the drum for transfer to media or an intermediate transfer member and later the media, further including a power supply in communication with a controller, a method comprising:
with the power supply, setting a first voltage on a charge roll that creates a second voltage on a surface of the drum;
based on the first and second voltages, transferring the toner from a developer roll to the drum;
sensing a current between the developer roll and the drum; and
providing a resistor through which the current is sensed and the sensed current having a corresponding voltage being amplified and provided to the controller.

### Claim 18

In an imaging device having a supply of toner in communication with a toner adder roll for providing the toner to a developer roll opposing a photoconductive drum to develop with the toner a latent image on the drum for first transfer to an intermediate transfer member and second transfer to media, further including a high voltage power supply in communication with a controller, a method comprising:
with the power supply, setting a first voltage on a charge roll that creates a second voltage on a surface of the drum;
based on the first and second voltages, transferring the toner from a developer roll to the drum;
sensing a current between the developer roll and the drum, including determining a first current of the latent image and a second current of a Paschen breakdown between the developer roll and the drum, further storing the first and second currents in a memory accessible by the controller, the controller subtracting from the current the first and second currents; and
providing the current or corresponding voltage to the controller for determining a mass of the toner for setting with the power supply an operating voltage on the drum or developer roll.

### Claim 19 (depends on 18)

The method of claim 18, further including developing a toner patch on the intermediate transfer member and projecting a light on the toner patch, further collecting the light scattered from the toner patch and the controller determining a toner mass from the light scattered.

### Claim 20

(canceled)