# US 11,305,541 B2 · Inkjet print heads cleaning system

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

- Number: US 11,305,541 B2
- Document ID: US11305541B2
- Status: Granted
- Kind: B2
- Application number: 17/441,997
- Filed: 2020-03-23
- Published: 2022-03-24
- Granted: 2022-04-19
- Earliest claimed: 2019-03-22
- Assignees: Nano Dimension Technologies, Ltd.
- Applicants: Nano Dimension Technologies LTD.
- Inventors: Tomer Friedman; Salamon Mekonen
- Web page: https://patentgrep.com/patent/US11305541B2

## CPC

- B41J 2/16508: {connected with the printer frame}
- B41J 2/16526: {by applying pressure only}
- B41J 2/16552: {using cleaning fluids}
- B41J 2/18: Ink recirculation systems
- B41J 2002/16573: {Cleaning process logic, e.g. for determining type or order of cleaning processes}
- B41J 2002/16594: {Pumps or valves for cleaning}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

The disclosure relates to a portable system for cleaning ink jet print heads. Specifically, the disclosure relates to external, portable systems and jig assemblies for cleaning clogged nozzles of ink jet print head under controlled pressure. The jig assembly can be self-contained and detachable, and can be programmed to operate upon receiving various signals indicating clogged nozzle plate or portion thereof, and/or as a routine maintenance operating procedure.

## Claims

### Claim 1

A computerized system for unclogging nozzle plate of an ink jet print head comprising:
a. a pressure pump;
b. a pressure relief valve in fluid communication with the pressure pump;
c. a cleaning fluid vessel in fluid communication with the pressure relief valve;
d. an ink jet print head having an inlet, a drain outlet and a nozzle plate, the ink jet print head being in fluid communication with the cleaning fluid vessel;
e. a switch valve, the switch valve being in fluid communication with the ink jet print head and a bath;
f. the bath;
g. a filter module in fluid communication with the switch valve;
h. a recirculating pump in fluid communication with the filter module and the cleaning fluid vessel; and
i. a central processing module (CPM), in communication with the pressure pump, the pressure relief valve, the ink jet print head, the switch valve, the filter module, and the recirculating pump.

### Claim 2 (depends on 1)

The system of claim 1, wherein the system further comprises at least one pressure gauge in communication with the filter module.

### Claim 3 (depends on 2)

The system of claim 2, wherein the CPM is in communication with the at least one pressure gauge.

### Claim 4 (depends on 3)

The system of claim 3, wherein the CPM further comprises:
a. a user interface module;
b. a display;
c. at least one processor; and
d. a non-volatile memory having thereon a processor-readable medium with a set of executable instructions.

### Claim 5 (depends on 4)

The system of claim 4, wherein the set of executable instruction is configured, when executed, to cause the at least one processor included in the CPM to:
a. using the pressure pump, pressurize the cleaning fluid vessel, causing cleaning fluid to flow into the ink jet print head's inlet; and
b. actuate the switch valve and the recirculating pump, circulating the cleaning fluid through the filter module, to the cleaning fluid vessel, the ink jet print head inlet, and the ink jet print head drain outlet;
c. actuate the switch valve, circulating the cleaning fluid through the ink jet print head nozzle plate and into the bath, and from the bath, through the switch valve to the filter module and to the cleaning fluid vessel; and
d. stop the pressure valve, actuate the switch valve, and close the relief valve, circulating the fluid from the bath to the cleaning fluid vessel.

### Claim 6 (depends on 5)

The system of claim 5, wherein the set of executable instruction is further configured, when executed, to cause the at least one processor included in the CPM to repeat the steps of claim 5 for a predetermined number of cycles.

### Claim 7 (depends on 6)

The system of claim 6 wherein the predetermined number of cycles is between 3 and 10.

### Claim 8 (depends on 7)

The system of claim 7 wherein the set of executable instruction is further configured, when executed, to cause the at least one processor included in the CPM to actuate at least one of: circulate the cleaning fluid at a fixed time interval for a predetermined period, and circulate the cleaning fluid in response to a signal received from the at least one pressure gauge.

### Claim 9 (depends on 8)

The system of claim 8, wherein the set of executable instruction is further configured, when executed, to cause the at least one processor included in the CPM to:
a. in response to a signal received by the CPM, stop the recirculating pump;
b. stop the pressure pump; and
c. using the pressure relief valve, release residual system pressure.

### Claim 10 (depends on 9)

The system of claim 9, further comprising at least one of: an imaging module and a calibration module, the imaging module and the calibration module operable, each or in combination to detect a clogged nozzle plate or portion thereof.

### Claim 11 (depends on 10)

The system of claim 10, wherein the signal is received from at least one of: the imaging module, and the calibration module.

### Claim 12 (depends on 6)

The system of claim 6, wherein the pressure relief valve is configured to relieve any pressure above 0.987 Atm.

### Claim 13 (depends on 8)

The system of claim 8, wherein the signal is a pressure increase of more than a predetermined degree in the at least one pressure gauge.

### Claim 14 (depends on 13)

The system of claim 13, wherein the signal is a lapse of time of more than a predetermined period.

### Claim 15 (depends on 1)

The system of claim 1, wherein the filter module comprises a 3 μm filter.

### Claim 16

A computerized method of unclogging an ink jet print head nozzle plate, implementable in a system comprising: a pressure pump, a pressure relief valve in fluid communication with the pressure pump, a cleaning fluid vessel in fluid communication with the pressure relief valve, an ink jet print head having an inlet, a drain outlet and a nozzle plate, the ink jet print head being in fluid communication with the cleaning fluid vessel, a switch valve, the switch valve being in fluid communication with the ink jet print head and a bath, the bath, a filter module in fluid communication with the switch valve, a recirculating pump in fluid communication with the filter module and the cleaning fluid vessel, a pressure gauge in communication with the filter module, and a central processing module (CPM), in communication with the pressure pump, the pressure relief valve, the ink jet print head, the switch valve, the filter module, and the recirculating pump, the method comprising:
a. upon at least one of:
i. at a fixed time interval of the ink jet print head printing;
ii. receiving a command by the CPM; and
iii. receiving a signal indicating the ink jet print head nozzle plate is clogged activating the pressure pump, and the recirculating pump as well as actuating the switch valve;
b. circulating the cleaning fluid through the ink jet print head inlet to the drain outlet, through the switch valve to the filter module and to the cleaning fluid vessel;
c. actuating the switch valve for circulating the cleaning fluid through the ink jet print head nozzle plate and into the bath; and
d. upon at least one of:
i. a predetermined lapse of time; and
ii. receiving a command by the CPM,
shutting the pressure pump, actuating the switch valve, and closing the relief valve thus draining the fluid from the bath, through the filter module to the cleaning fluid vessel.

### Claim 17 (depends on 16)

The method of claim 16, wherein the CPM further comprises:
a. a user interface module;
b. a display;
c. at least one processor; and
d. a non-volatile memory storage device storing thereon a processor-readable medium with a set of executable instructions, configured, when executed to cause the at least one processor to perform the steps of claim 16.

### Claim 18 (depends on 17)

The method of claim 17, wherein the system further comprises at least one of: an imaging module, and a calibration module, the imaging module and the calibration module operable, each or in combination to detect a clogged and unclogged nozzle plate or a portion thereof, and wherein the signal indicating that the ink jet print head's nozzle plate or a portion thereof is clogged or unclogged is received from at least one of: the imaging module, and the calibration module.

### Claim 19 (depends on 18)

The method of claim 18, wherein the step of actuating the switch valve and the recirculating pump is preceded by:
a. printing a test pattern; and
b. analyzing the test pattern;
c. determining if the nozzle plate is clogged; and
d. if the nozzle plate is clogged, then coupling the cleaning fluid vessel in fluid communication with the pressure relief valve to the ink jet print head's inlet, and the switch valve, the filter module and the recirculating pump to the drain outlet while placing the bath beneath the ink jet print head's nozzle plate; else
e. using the ink jet print head.

### Claim 20 (depends on 17)

The method of claim 17 wherein the command received by the CPM for at least one of the step of actuating the switch valve and the recirculating pump, and the step of stopping the pressure pump and the recirculating pump is input by a user using the user interface.

### Claim 21 (depends on 19)

The method of claim 19, further comprising repeating the steps from actuating the switch valve and the recirculating pump, to the step of actuating the switch valve, and closing the pressure relief valve thus circulating the fluid from the bath to the cleaning fluid vessel for between 3 and 10 cycles.

### Claim 22 (depends on 21)

The method of claim 21, further comprising, after a last cycle of the between 3 and 10 cycles, printing the test pattern; and
a. if the print pattern indicates a clogged nozzle plate or portion thereof, repeating the steps of actuating the switch valve and the recirculating pump, to the step of actuating the switch valve, and closing the pressure relief valve thus circulating the fluid from the bath to the cleaning fluid vessel for an additional at least one cycle; else
b. if the printed test pattern indicates an open nozzle plate or portion thereof, then decoupling the cleaning fluid vessel in fluid communication with the pressure relief valve from the ink jet print head's inlet, and the switch valve, the filter module and the recirculating pump from the drain outlet while removing the bath from beneath the ink jet print head's nozzle plate and resuming use of the ink jet print head.