Objective is to detect objectionable distortion in impact glass. E.g. an Insulated Glass (IG) of two panes laminated and ½ to ¾" insulator air space and a single pane in the makeup and all glass is tempered. Detection will be at incoming inspection of the window fabricator. Expected failure rate is .5%.
Objectionable distortion is typically noticed by an observer when they are 8 to 16 feet away from the glass and the subject viewed on other side is 20 to 1000 feet away. Millidiopters e.g. as in reading glasses caused by tempering process effecting the observation is 200 to 500. Or just an anomaly in the glass could be the cause. Another is buffing out scratches which if not feathered correctly leaves a slight concave depression in the glass surface. My tests show that a laser line projected at 30 degrees off center will show this kind of distortion as a "squiggle" on a white board. That is, when millidiopters is 200-300 on the glass surface and line is projected through the IG at 15 feet away from glass and white board 15 feet away on the other side. I’m using a simple green laser pen with a line lens. This is very difficult to see with a 50mw laser through tinted glass. So – I would like to use a laser to about 200mw and control the projected line height from 2 feet to 6 feet, sat 20 to 30 degrees. Width about 1-2 mm. Seems a galvo would work. I haven’t a clue on how to program or establish a signal source that would give just a line as described. The lens approach itself has too much distortion or what looks to be harmonics (?), and is thicker and brighter one end, and height is not easily controllable. I would like to keep the proto type project around 1K$. I find a fan cooled laser, Galvo and PS on line for under the 1K$ limit. On time cycle is about 10 – 5 minutes on with 2-5 minutes off.
Got any ideas for signal source to create the line? Galvo is 20KPS.
Thanks
