# US 8,740,325 B2 · Method for printing in a printer having an inoperable ink reservoir

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- Number: US 8,740,325 B2
- Document ID: US8740325B2
- Status: Granted
- Kind: B2
- Application number: 12/966,058
- Filed: 2010-12-13
- Published: 2012-06-14
- Granted: 2014-06-03
- Earliest claimed: 2010-12-13
- Assignees: Xerox Corporation
- Applicants: Michael Joseph Dahrea; Michael William Elliot
- Inventors: Michael Joseph Dahrea; Michael William Elliot
- Web page: https://patentgrep.com/patent/US8740325B2

## CPC

- B41J 2/17566: {Ink level or ink residue control}
- B41J 2/17509: {Whilst mounted in the printer}
- B41J 2/17593: {Supplying ink in a solid state}
- B41J 2/2142: {Detection of malfunctioning nozzles (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579)}
- B41J 11/425: {for a variable printing material feed amount}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A method for operating a printer includes supplying liquid ink from two ink reservoirs to a printhead to enable the printhead to eject ink drops onto an image receiving substrate. A substrate transport moves the substrate past the printhead at a first speed. In response to detecting an interruption in the supply of liquid ink from one of the two ink reservoirs, the substrate transport moves the image receiving substrate at a slower second speed past the printhead.

## Claims

### Claim 1

A method of operating a printing device comprising:
supplying liquid ink from a first ink reservoir to a printhead to enable the printhead to eject ink drops onto an image receiving substrate;
supplying liquid ink from a second ink reservoir to the printhead to enable the printhead to eject ink drops onto the image receiving substrate, the first and the second ink reservoirs each maintaining a supply of ink that is separate from a supply of ink in the other reservoir;
operating a substrate transport to move the image receiving substrate at a first speed in a process direction past the printhead coupled to the first ink reservoir and the second ink reservoir;
detecting an interruption in the supply of liquid ink from one of the first ink reservoir and the second reservoir to the printhead; and
modifying operation of the substrate transport to move the image receiving substrate at a second speed in the process direction past the printhead coupled to the first ink reservoir and the second ink reservoir in response to the detection of the interruption of liquid ink being supplied from one of the first ink reservoir and second ink reservoir to the printhead, the second speed being lower than the first speed.

### Claim 2 (depends on 1)

The method of claim 1, the detection of the interruption of liquid ink being supplied to the printhead from one of the first reservoir and the second reservoir further comprising:
detecting an ink level in one of the first ink reservoir and the second ink reservoir falling below a predetermined ink level threshold while an ink level in the other of the first ink reservoir and the second ink reservoir remains at or above the predetermined threshold.

### Claim 3 (depends on 1)

The method of claim 1, the modification of the substrate transport operation further comprising:
stopping movement of the image receiving substrate in the process direction in response to the detection of the interruption of liquid ink being supplied from one of the first ink reservoir and the second ink reservoir to the printhead;
reversing the image receiving substrate by a distance that corresponds to a time interval between the detection of the interruption of liquid ink and the image receiving substrate coming to a stop; and
resuming movement of the image receiving member in the process direction in response to termination of the interruption of liquid ink being supplied from one of the first ink reservoir and the second ink reservoir to the printhead.

### Claim 4 (depends on 1)

The method of claim 1 further comprising:
supplying ink to the one of the first and second ink reservoirs from which the liquid ink supply has been detected as being interrupted.

### Claim 5 (depends on 4)

The method of claim 4 further comprising:
coupling the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted to a melting device to enable the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted to receive liquid ink from the melting device in response to the detection of the interruption of the liquid ink supply from the one of the first ink reservoir and the second ink reservoir.

### Claim 6 (depends on 5)

The method of claim 5 further comprising:
venting to atmospheric pressure the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted to facilitate liquid ink flowing from the melting device into the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted; and
pressurizing the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted after the liquid ink has been received from the melting device.

### Claim 7 (depends on 1)

The method of claim 1, the detection of the interruption of liquid ink being supplied to the printhead further comprising:
detecting a reduction in a predetermined volumetric rate at which liquid ink is supplied to one of the first and second ink reservoirs; and
modifying operation of the substrate transport to move the image receiving substrate at the second speed in response to the detection in the reduction of the volumetric rate at which liquid ink is being supplied to the one of the first and the second ink reservoirs.

### Claim 8

A printing apparatus, comprising:
a first ink reservoir, the first ink reservoir being configured to hold liquid ink;
a first level sensor positioned within the first ink reservoir, the level sensor being configured to identify a level of liquid ink in the first ink reservoir;
a second ink reservoir, the second ink reservoir being configured to hold liquid ink, the first and the second ink reservoirs each maintaining a supply of ink that is separate from a supply of ink in the other reservoir;
a second level sensor positioned within the second ink reservoir, the level sensor being configured to identify a level of liquid ink in the second ink reservoir;
a printhead fluidly coupled to the first ink reservoir and the second ink reservoir, the printhead being configured to eject drops of ink received from the first ink reservoir and the second ink reservoir onto an image receiving substrate;
a substrate transport, the substrate transport being configured to move the image receiving substrate at a first speed in a process direction past the printhead that is fluidly coupled to the first ink reservoir and the second ink reservoir; and
a controller operatively connected to the substrate transport, the first level sensor, and the second level sensor, the controller being configured to operate the substrate transport to move the image receiving substrate at a second speed in the process direction in response to the controller detecting an interruption in liquid ink being supplied from one of the first ink reservoir and the second ink reservoir to the printhead, the second speed being less than the first speed.

### Claim 9 (depends on 8)

The printing apparatus of claim 8, the controller being further configured to receive a signal from the first level sensor and the second level sensor to detect an ink level in the first ink reservoir and an ink level in the second ink reservoir, to compare the ink level in the first ink reservoir to a first ink level threshold and the ink level in the second ink reservoir to a second ink level threshold, and to detect the interruption of liquid ink being supplied to the printhead in response to one of the ink levels being below the predetermined ink level threshold to which the ink level was compared while the other ink level is at or above the predetermined ink level threshold to which the other ink level was compared.

### Claim 10 (depends on 8)

The printing apparatus of claim 8, the controller being further configured to operate the substrate transport to stop movement of the image receiving substrate in the process direction in response to the detection of the interruption of liquid ink being supplied from one of the first ink reservoir and the second ink reservoir to the printhead, to reverse the image receiving substrate by a distance that corresponds to a time interval between the detection of the interruption of liquid ink and the image receiving substrate coming to a stop, and to resume movement of the image receiving member in the process direction in response to termination of the interruption of liquid ink being supplied from one of the first ink reservoir and the second ink reservoir to the printhead.

### Claim 11 (depends on 8)

The printing apparatus of claim 8, the controller being further configured to enable liquid ink to be supplied to the one of the first and second ink reservoirs from which the liquid ink supply has been detected as being interrupted.

### Claim 12 (depends on 11)

The printing apparatus of claim 11, the controller being further configured to couple the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted to a melting device to enable the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted to receive liquid ink from the melting device in response to the detection of the interruption of the liquid ink supply from the one of the first ink reservoir and the second ink reservoir.

### Claim 13 (depends on 12)

The printing apparatus of claim 12, the controller being further configured to vent to atmospheric pressure the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted to facilitate liquid ink flowing from the melting device into the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted, and to activate a pressure source to pressurize the one of the first ink reservoir and the second ink reservoir from which the liquid ink supply was detected as being interrupted after the liquid ink has been received from the melting device.

### Claim 14 (depends on 8)

The printing apparatus of claim 8, the controller being further configured to detect a reduction in a predetermined volumetric rate at which liquid ink is supplied to one of the first and second ink reservoirs to detect the interruption of liquid ink from one of the first ink reservoir and the second ink reservoir, and to modify operation of the substrate transport to move the image receiving substrate at the second speed in response to the detection in the reduction of the volumetric rate at which liquid ink is being supplied to the one of the first and the second ink reservoirs.