# US 5,706,038 A · Wet wiping system for inkjet printheads

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- Number: US 5,706,038 A
- Document ID: US5706038A
- Status: Granted
- Kind: A
- Application number: 08/330,900
- Filed: 1994-10-28
- Granted: 1998-01-06
- Earliest claimed: 1994-10-28
- Assignees: Hewlett-Packard Company
- Inventors: Kedrich J. Jackson; Thomas J. Purwins
- Web page: https://patentgrep.com/patent/US5706038A

## CPC

- B41J 2/16538: {with brushes or wiper blades perpendicular to the nozzle plate}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A wet wiping system is provided that is particularly useful for wiping an inkjet printhead that uses pigment based ink. A wet wiping method comprises an admitting step, where ink is admitted though printhead nozzles, either by firing the inkjet cartridge with a low thermal turn on energy, or through capillary action provided by placing the printhead in contact with a wicking pad. In a dissolving step, any accumulated ink residue adjacent the nozzles is dissolved with the admitted ink. In a wiping step, the admitted ink and any dissolved ink residue is wiped from the printhead. One wet wiper has a cellulose acetate polyester blade supported on at least one side by a foam block. The wicking pad may have a ramped portion for gradually contacting the printhead, or a domed wicking surface that is compressed upon contact with the printhead to facilitate the capillary action.

## Claims

### Claim 1

A method of wiping an inkjet printing mechanism, comprising the steps of:
placing the printhead in contact with a wicking pad covered with a smooth wicking surface of an ink non-retaining, capillary action inducing material comprising:
(a) a matte surface of mylar film,
(b) an adhesive tape, or
(c) a skinned material overlaying the wicking pad, when the wicking is a body of a compliant material comprising a modified open cell polyurethane foam;
admitting ink through a nozzle of the ink jet printhead by extracting ink from the printhead through capillary action induced by the wicking pad;
dissolving any accumulated ink residue adjacent the nozzle with the admitted ink; and
wiping the admitted ink and any dissolved residue from the printhead.

### Claim 2 (depends on 1)

A method according to claim 1, wherein the placing step comprises placing the printhead in contact with a wicking pad having a body of a compliant material comprising a felt material.

### Claim 3 (depends on 1)

A method according to claim 1, further including a step of agitating the printhead by reciprocal back and forth relative movement of the printhead and wicking pad during the extracting step.

### Claim 4 (depends on 1)

A method according to claim 1, wherein the admitting step also comprises the step of ejecting ink by firing the printhead before the extracting step.

### Claim 5 (depends on 1)

A method according to claim 1, wherein the placing step comprises the step of moving the wicking pad into contact with the printhead held in a fixed position.

### Claim 6 (depends on 1)

A method according to claim 1, wherein the placing step comprises placing the printhead in contact with a wicking pad having a body of a compliant material comprising a cellulosic fiber material.

### Claim 7 (depends on 1)

A method according to claim 1, the placing step comprises the step of prewiping the printhead by moving the printhead along an inclined portion of the wicking pad.

### Claim 8 (depends on 1)

A method according to claim 1, wherein the wiping step comprises wiping the printhead with a wiper of a plastic material braced between a pair of resilient foam members.

### Claim 9 (depends on 1)

A method according to claim 1, wherein the placing step comprises placing the printhead in contact with a wicking pad having a body of a compliant material.

### Claim 10 (depends on 1)

A method according to claim 1, wherein the placing step comprises placing the printhead in contact with a wicking pad having a body of a compliant material comprising a sponge-like material.

### Claim 11 (depends on 1)

A method according to claim 1, wherein the placing step comprises placing the printhead in contact with a wicking pad having a body of a compliant material comprising a foam material.

### Claim 12

A wet wiping system for wiping an inkjet printhead used in an inkjet printing mechanism, comprising:
a service station mounted to a chassis of the printing mechanism; and
a wicking pad having a smooth wicking surface of an ink non-retaining, capillary action inducing material comprising:
(a) a matte surface of a mylar film,
(b) an adhesive tape, or
(c) a skinned material overlaying the wicking pad, when the wicking is a body of a compliant material comprising a modified open cell polyurethane foam,
with the pad supported by the service station to selectively contact the printhead with the wicking surface to extract ink therefrom through capillary action between the printhead and the smooth wicking surface.

### Claim 13 (depends on 12)

A wet wiping system according to claim 12 wherein the wicking pad has a body of a compliant material comprising a felt material.

### Claim 14 (depends on 12)

A wet wiping system according to claim 12 wherein the wicking pad has a body of a compliant material comprising a cellulosic fiber material.

### Claim 15 (depends on 12)

A wet wiping system according to claim 12 wherein the wicking pad has a the body of a compliant material comprising a modified open cell polyurethane foam material.

### Claim 16 (depends on 15)

A wet wiping system according to claim 15 wherein the wicking pad has a domed wicking surface which is compressed when contacted by the printhead.

### Claim 17 (depends on 15)

A wet wiping system according to claim 15 wherein the wicking pad has a ramped portion extending from a surface of the service station to the pad wicking surface.

### Claim 18 (depends on 12)

A wet wiping system according to claim 12 further including a wiper mounted to the service station to selectively wipe the printhead after extraction of ink from the printhead using the wicking pad, with the wiper comprising a wiping member of a plastic material and a pair of resilient support members each comprising a block of a foam material mounted to the service station with the wiping member sandwiched therebetween.

### Claim 19 (depends on 12)

A wet wiping system according to claim 12 wherein the wicking pad has a body of a compliant material.

### Claim 20 (depends on 12)

A wet wiping system according to claim 12 wherein the wicking pad has a body of a compliant material comprising a sponge-like material.

### Claim 21 (depends on 12)

A wet wiping system according to claim 12 wherein the wicking pad has a body of a compliant material comprising a foam material.

### Claim 22

An inkjet printing mechanism, comprising:
a chassis;
a carriage that transports an inkjet printhead across a print zone and a printhead servicing region; and
a service station mounted to the chassis, the service station including a platform and a wicking pad having a smooth wicking surface of an ink non-retaining, capillary action inducing material comprising:
(a) a matte surface of a mylar film,
(b) an adhesive tape, or
(c) a skinned material overlaying the wicking pad, when the wicking is a body of a compliant material comprising a modified open cell polyurethane foam,
with the pad supported by the service station to selectively contact the printhead with the wicking surface to extract ink therefrom through capillary action between the printhead and the smooth wicking surface.

### Claim 23 (depends on 22)

An inkjet printing mechanism according to claim 22 wherein the wicking pad has a body of a compliant material comprising a felt material.

### Claim 24 (depends on 22)

An inkjet printing mechanism according to claim 22 wherein the wicking pad has a body of a compliant material comprising a cellulosic fiber material.

### Claim 25 (depends on 22)

An inkjet printing mechanism according to claim 22 wherein the wicking pad has a body of a compliant material comprising a modified open cell polyurethane foam material.

### Claim 26 (depends on 25)

An inkjet printing mechanism according to claim 25 wherein the wicking pad has a domed wicking surface which is compressed when contacted by the printhead.

### Claim 27 (depends on 25)

An inkjet printing mechanism according to claim 25 wherein the wicking pad has a ramped portion extending from a surface of the service station to the pad wicking surface.

### Claim 28 (depends on 22)

An inkjet printing mechanism according to claim 22 further including a wiper mounted to the service station to selectively wipe the printhead after extraction of ink from the printhead using the wicking pad, with the wiper comprising a wiping member of a plastic material and a pair of resilient support members each comprising a block of a foam material mounted to the service station with the wiping member sandwiched therebetween.

### Claim 29 (depends on 22)

An inkjet printing mechanism according to claim 22 wherein the wicking pad has a body of a compliant material.

### Claim 30 (depends on 22)

An inkjet printing mechanism according to claim 22 wherein the wicking pad has a body of a compliant material comprising a sponge-like material.

### Claim 31 (depends on 22)

An inkjet printing mechanism according to claim 22 wherein the wicking pad has a body of a compliant material comprising a foam material.
