# US 10,369,802 B2 · Ink filter with passive de-aeration

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

- Number: US 10,369,802 B2
- Document ID: US10369802B2
- Status: Granted
- Kind: B2
- Application number: 16/022,449
- Filed: 2018-06-28
- Published: 2019-01-10
- Granted: 2019-08-06
- Earliest claimed: 2017-07-10
- Assignees: Memjet Technology Limited
- Applicants: Memjet Technology Limited
- Inventors: Patrick McAuliffe
- Web page: https://patentgrep.com/patent/US10369802B2

## CPC

- B41J 2/17563: {Ink filters}
- B41J 2/175: Ink supply systems {; Circuit parts therefor}
- B41J 2/17596: {Ink pumps, ink valves}
- B41J 2/18: Ink recirculation systems
- B41J 2/19: for removing air bubbles
- B41J 2/195: for monitoring ink quality
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

An ink filter for an ink delivery system. The ink filter includes: a filter chamber having a filter inlet port, a filter outlet port and a vent port, the vent port being positioned in a roof of the filter chamber; a filter material positioned between the filter inlet port and the filter outlet port; and a closed vent chamber connected to the vent port. The vent chamber has wall exposed to atmosphere formed of an air-permeable polymer.

## Claims

### Claim 1

An ink filter for an ink delivery system comprising:
a filter chamber having a filter inlet port, a filter outlet port and a vent port, the vent port being positioned in a roof of the filter chamber;
a filter material positioned between the filter inlet port and the filter outlet port; and
a closed vent chamber connected to the vent port,
wherein the vent chamber has at least one wall exposed to atmosphere comprised of an air-permeable polymer.

### Claim 2 (depends on 1)

The ink filter of claim 1, wherein the vent chamber is comprised of air-permeable polymer tubing having one end connected to the vent port and an opposite end capped.

### Claim 3 (depends on 1)

The ink filter of claim 1, wherein the polymer tubing extends generally upwards from the vent port and defines sidewalls of the vent chamber.

### Claim 4 (depends on 1)

The ink filter of claim 1, wherein the vent port is positioned for removing air bubbles from unfiltered ink in the filter chamber.

### Claim 5 (depends on 1)

The ink filter of claim 1, wherein the air-permeable polymer has an oxygen permeability in the range of 5 to 50 Barrer (16.74 to 167.4×10−19 kmol m/(m2 s Pa)).

### Claim 6 (depends on 1)

The ink filter of claim 1, wherein the vent chamber is connected to the vent port via a diffusion tube.

### Claim 7 (depends on 6)

The ink filter of claim 6, wherein the diffusion tube has sidewalls impermeable to air.

### Claim 8 (depends on 6)

The ink filter of claim 6, wherein the diffusion tube has a length in the range of 1 to 10 cm.

### Claim 9 (depends on 1)

The ink filter of claim 1, wherein vent chamber contains ink at a positive hydrostatic pressure for a majority of time over the lifetime of a printer incorporating the ink filter.

### Claim 10 (depends on 9)

The ink filter of claim 9, wherein the vent chamber contains ink at a positive hydrostatic pressure during idle periods of the printer incorporating the ink filter.

### Claim 11

An inkjet printer comprising:
an ink tank containing ink having a predetermined ink level;
an ink filter positioned below the predetermined ink level; and
an inkjet printhead positioned above the predetermined ink level,
wherein the ink filter comprises:
a filter chamber having a filter inlet port for receiving ink from the ink tank, a filter outlet port for delivering ink to the printhead and a vent port, the vent port being positioned in a roof of the filter chamber;
a filter material positioned between the filter inlet port and the filter outlet port; and
a closed vent chamber connected to the vent port,
and wherein the vent chamber has at least one wall exposed to atmosphere comprised of an air-permeable polymer.

### Claim 12 (depends on 11)

The printer of claim 11, wherein the vent chamber is comprised of air-permeable polymer tubing having one end connected to the vent port and an opposite end capped.

### Claim 13 (depends on 11)

The printer of claim 11, wherein the polymer tubing extends generally upwards from the vent port and defines sidewalls of the vent chamber.

### Claim 14 (depends on 11)

The printer of claim 11, wherein the vent port is positioned for removing air bubbles from unfiltered ink in the filter chamber.

### Claim 15 (depends on 11)

The printer of claim 11, wherein the air-permeable polymer has an oxygen permeability in the range of 5 to 50 Barrer (16.74 to 167.4×10−19 kmol m/(m2 s Pa)).

### Claim 16 (depends on 11)

The printer of claim 11, wherein the vent chamber is connected to the vent port via a diffusion tube.

### Claim 17 (depends on 11)

The printer of claim 11, wherein the vent chamber contains ink at a positive hydrostatic pressure during idle periods of the printer.

### Claim 18 (depends on 17)

The printer of claim 17, wherein the air-permeable polymer has sufficient permeability to allow recovery of the ink filter within 20 days at a predetermined positive hydrostatic pressure.

### Claim 19 (depends on 11)

The printer of claim 11, wherein at least part of the vent chamber is positioned above the predetermined ink level.

### Claim 20 (depends on 11)

The printer of claim 11, wherein at least part of the vent chamber is positioned below the predetermined ink level.