Monitoring printing fluid

1 . A printing fluid monitoring device comprising:

a light emitter to pass light through a fluid line comprising a flowing printing fluid;

an image sensor to capture a diagnostic image of the flowing printing fluid in the fluid line once the light has passed through the fluid line; and

a processor connected to the image sensor to compare the diagnostic image to a baseline and to determine a presence of printing fluid sludge based on the comparison.

2 . The device of claim 1 further comprising a housing to enclose the light emitter, the image sensor and the fluid line.

3 . The device of claim 2 wherein the housing comprises a clamping mechanism as to clamp the housing over the fluid line.

4 . The device of claim 2 wherein the housing comprises a printing fluid inlet and a printing fluid outlet to be connected to the fluid line of a printing system.

5 . The device of claim 1 wherein the image sensor is to capture images at a frequency of at least 20 Hz and the processor is to determine the presence of printing fluid sludge based on the images in real-time.

6 . The device of claim 1 wherein the baseline comprises a set of previously acquired images.

7 . The device of claim 6 wherein the processor comprises a machine learning engine and the set of images previously acquired are part of a training set for the machine learning engine.

8 . The method of claim 6 wherein the method is performed at a frequency of above 20 Hz and processed in real-time.

9 . The device of claim 1 wherein the processor comprises a computer vision engine to determine the presence of printing fluid sludge from the diagnostic image.

10 . The device of claim 1 wherein the processor is to compare a color density across the diagnostic image and determine the presence of printing fluid sludge based on differences in color density across the diagnostic image.

11 . A printing system, including:

a printing fluid delivery sub-system;

a light emitter to pass light through a fluid line associated with the fluid delivery sub-system, the fluid line comprising a printing fluid flowing therethrough;

an image sensor to capture, from the light passing through the fluid line, a diagnostic image including a portion of the fluid line and the printing fluid; and

a processor to determine a presence of printing fluid sludge based on performing an image processing operation on the diagnostic image.

12 . The printing system of claim 11 wherein the presence of printing fluid sludge is based on a detection of clogs in the diagnostic image.

13 . The printing system of claim 11 wherein the image processing operation comprises comparing the diagnostic image to a baseline.

14 . The printing system of claim 11 wherein the light emitter is to pass light through a plurality of fluid lines with a plurality of printing fluids, the image sensor is to capture a diagnostic image from the light passing through the plurality of fluid line including a portion of each of the plurality of fluid lines and their respective printing fluids and the processor is to determine a plurality of presence of printing fluid sludge based on performing an image processing operation for each of the plurality of printing fluids.

15 . A fluid monitoring method comprising:

pass light, by a light source, through a printing fluid conductor comprising printing fluid;

acquire, by an image sensor and the light passing through the printing fluid conductor, a diagnostic image of the printing fluid in the printing fluid conductor;

determine, by a processor, a presence of printing fluid sludge based on the diagnostic image;

wherein the presence of printing fluid sludge is determined based on a comparison between the diagnostic image and a baseline accessible by the processor.