Hewlett-packard Development Company, L.p.

Chin Hung Andy Koh

Xiaoxi Huang

Tong Nam Samuel Low

Fei Guo

Shyh Chije Leong

Jennifer Marie McCord Brister

Jeffrey Anderson

Ganlin Tang

Lim Cheng Woon

Yick Wai Yvonne Audrey Ho

Chee Beng Teo

Siew Hong Lam

Sai Horng Soo

Ginu Jacob

Biyun Phoa

According to examples, an apparatus may include a processor and a memory on which are stored computer-readable instructions that, when executed by the processor, may cause the processor to identify first property values along an image of a pattern. The first property values may be identified based on a first signal corresponding to an image of the pattern captured by an imaging sensor. The pattern may be positioned at a spaced relation with respect to the imaging sensor. The processor may receive a second signal corresponding to a second image captured by the imaging sensor, and may identify, from the second signal, second property values along the second image. Based on a determination that the second property values differ from the first property values, the processor may determine that a beginning of a media is positioned to be imaged by the imaging sensor.

Media position determination based on images of patterns captured by imaging sensors

In one embodiment, a stated reflectance identifier for a media to be printed on during fulfillment of a print job is received. Utilizing an optical sensor and an illuminator, a measurement is taken of light from the illuminator reflected off the media. The measurement is compared to a stored average brightness value. Responsive to determining the measurement is within a range of the average value, the average value is adjusted to include the measurement, and printing on the media is caused according to the job. Responsive to determining the measurement is outside the range, the measurement is compared to a database associating brightness measurements and reflectance identifiers to determine an estimated reflectance identifier for the media. The estimated identifier is sent to a user and the user is prompted to perform a correction event. The media is printed on according to the job.

Media reflectance identifiers

Systems and methods for calibrating scanning devices are described. The method comprises dividing a dark scan image of a calibration strip into one or more regions. The dark scan image is further analyzed to obtain at least one data point from each of the one or more regions. Further, calibration values for each of the one or more regions are computed based on the at least one data point for calibrating the scanning device. The calibration values include mean and standard deviation of the data points for each of the one or more regions.

Calibration of scanning devices

One or more preventative maintenance mode parameters for an inkjet-printing device having an inkjet-printing mechanism are determined based on a water loss rate of water from ink within the device and/or on an air gain rate of air into the ink within the device. As such, periodic performance of a non-user-initiated preventative maintenance mode based on the preventative maintenance mode parameters results in the ink within the inkjet-printing mechanism being sufficiently fresh so as not to affect quality of image formation by the inkjet-printing device. Therefore, the non-user-initiated preventative maintenance mode for the inkjet-printing device is periodically performed based on the preventative maintenance mode parameters to eject at least some of the ink from, and to refill fresh ink into, the inkjet-printing mechanism.

Non-user-initiated preventative maintenace modes for inkjet-printing device

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Singapore, Singapore

Chin Hung Andy Koh