Hewlett-packard Development Company, L.P.

Hp Indigo B.v.

Hewlett-packard Indigo B.v.

Amit, Gal

Gal Amit

Ran Waidman

Eyal Shelef

Tsafrir Yedid Am

Sasi Moalem

Shlomo Harush

Lior Katz

Nadav Barkai

Dror Kella

Shaul Haim Raz

Tsafrir Yedid-Am

Oren Bengigi

Ido Elad

In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.

Printing with target color data

Printing by determining target color values based on first color outputs, determining current color values based on current color outputs, and calculating color compensation values to compensate for a difference between the target color values and the current color values.

Printing with continuous color calibration

A method for position calibration of a spot of a known geometry of an optical sensor is disclosed. The method may include providing a position calibration patch on a sheet at a position which is known with respect to a reference position on the sheet, along a scan path of the spot of the optical sensor across the sheet. The patch may include at least two adjacent blocks of different colors. The method may also include obtaining a sampling of the position calibration patch using the optical sensor. The method may further include determining from the sampling a relative coverage of the spot over the color blocks of the position calibration patch, and based on the known geometry of the spot and on the determined relative coverage, determining the position of the spot of the sensor with respect to the reference position.

System and method for position calibration of a spot of an optical sensor

An embodiment of this disclosure involves printing color outputs on sheets, reading the color outputs and adjusting a calibration parameter.

Printing

A method for monitoring development parameters of a liquid toner electrophotographic (LEP) printer, the method comprising defining an operational window for a current utilized by the printer and monitoring the current to determine a deviation of the current outside the operational window.

Development monitoring method and system

A method for position calibration of a spot of an optical sensor may include providing a position calibration patch on a sheet at a predetermined position, along a scan path of the spot across the sheet, the patch comprising at least two adjacent blocks of different colors. The method may also include obtaining a single sample of the position calibration patch using the optical sensor. The method may further include determining from the single sample the position of the spot of the sensor with respect to the position calibration patch.

Position calibration of a spot of an optical sensor

In one embodiment, a media is advanced in the process direction to cause a plurality of fiducials to successively appear within a sensor's focal width. Each fiducial includes a target and a background, with the target superimposed to the background. Each target has a substantially same target width, a substantially same optical density, and a position at a distinct distance from an edge of the media. Each background has an optical density less than the optical density of the targets and greater than an optical density of the media. An optical density for each fiducial is read utilizing the sensor. The target the sensor is most aligned with is discerned by identifying an identified fiducial with the highest-read optical density. Utilizing data indicative of a position of the discerned target relative to a desired position, the sensor is caused to move to the desired position.

Method and system to position a sensor

A charge director injection system includes a charge director tank, a liquid toner tank, a charge director pump to pump charge director from the charge director tank into the liquid toner tank, and a control system configured to measure a change in charge density per amount of charge director injected into the liquid toner tank, and create a charge profile indicating a relationship between amount of charge director injected into the liquid toner and change in charge density of the liquid toner within the liquid toner tank.

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Bat Yam, Israel

Gal Amit