I ran into some issues with the Up Camera (new ones) when I needed to run vision with bigger components (like TQFP-64, 0.8mm pitch 1cmx1cm BGA’s, mezzamine connectors, FPC connectors etc.) It required the aperture of the diffuser to be larger to accommodate the component but the side of effect of that was to increase the brightness of the image. Brightness could be reduced via the camera settings but that reduced the dynamic range too, which couldn’t be compensated with constrast etc.
Basically black nozzle with white diffuser on a back blackground is hard for the camera, also components often contain
black in the too complicating the problem of recognition.
So I tried a green screening technique instead which has produced good results, the camera copes much better and everything can be masked out around the component using HSV, provided the component is larger than the nozzle tip, if not then the remaining can be thresholded out. The idea was to try a few colours that were unlikely to appear in components, that could be masked out and were close to R/G or B. Also, I wanted Matte to avoid specular highlights.
I tried a few colours, Yellow, Neon Green, Darker Green (aka Juki Nozzle Color) , Darker Hot Pink and Anti Static Mat Blue. Yellow and Neon Green were too bright and the camera saturated parts of the image. Darker Green was too dark and too close to black to be useful.
Anti Static Mat Blue produced reasonable results, but the Darker Hot Pink was the best.
First I found some nail polish colours and a clear matte topcoat and then went to the local home improvement store to match paint chips to those colours. The paint chips are free, often matte, and some are large enough to be able to use the card for nozzles and to replace the black Liteplacer Up Camera backdrop. (Also if you need a good black to replace the Liteplacer one, then they have some blacker and matte cards). For those in the US/Canada, Home Depot is where I got mine.
Then I took the CP40 nozzles that came with the Liteplacer and modded them as follows (being very careful
not to get anything on the flat tip of the nozzle or in the hole)
1. 2-3 coats nail polish on the top part of the nozzle down to the first elbow (takes a good few hours to dry
due to it being on metal.
2. Top coat of nail polish matte clear (to remove the specular highlights)
3. Cut a collar to slide over the elbow. A donut 6mm radius/1.75mm radius (for the outer 2 nozzles, to clear the support)
and 10mm radius/1.75mm radius for the inner 4 nozzles, all with a cut straight from the outer ring to the inner so they can be slid over the elbow. The idea is that when viewed from underneath, none of the black of the nozzle can be seen.
4. Glued the collar in place with a few small dabs of hot glue.
5. Touched up the collars with the nail polish and matte coat so that no white was showing and everything was matte
6. Replaced the black up camera background with the new card color.
When done this way, Hue and Saturation have a limited range which is easy to mask out, and Brightness will range from the nozzle tip to the background. Also changes in ambient background light will only effect brightness.
Also, because I had to lightly sand the anodization coat off the flat part of my nozzles to make them shiny for nozzle calibration in Liteplacer, I replaced it with a black color with a Permanent Marker as it’s not needed in OpenPNP.
Everything can be undone, nail polish, hot glue and permanent marker come off with 99% IPA. If you do get some nail polish on the top of the tip, just get paper towel soaked in IPA and wipe the tip against it to remove.
Here’s some pictures (Click to view):
- 819112C1-52DD-4AAF-9582-38F27E09B1B8.jpeg (95.16 KiB) Viewed 3226 times
- A99A91A4-9492-4FC2-89DC-74B992862674.jpeg (77.18 KiB) Viewed 3226 times