Wednesday, December 8, 2010

Still in the dark about pericentric imaging?

It must be at least two years since Italian lens maker, Opto Engineering unveiled their pericentric lens, and I’m still looking for an application where it makes sense. Don’t get me wrong, I think it’s a great product, it’s just that I believe line scan remains the best way to image an cylindrical part.

Line scan provides higher resolution, distortion-free images and allows better control over the illumination. That being said, there are some cases where the pericentric approach has merit, as shown in this video.



The weaknesses though are the sheer size and weight of the lens, plus its price. Don’t take my word for it though, get on to Opto Engineering and ask for a loan.

5 comments:

Spencer Luster said...

A hypercentric (or pericentric) lens isn't a good choice for many gauging applications, but often it's a wonderful tool for defect or presence/absence inspections.

Just last month a Light Works customer used some of our Hyper-Eye(tm) models to check for the completeness of foil seals around the finish of food product bottles. Inspection for presence of punched holes in cylinder walls, detection of debris, or verification of label features are some other applications for which we've provided hypercentric lenses. And unlike line scan camera applications, you don't have to rotate the part to achieve 360 degree inspection.

An additional benefit of Light Works hypercentric lenses (I can't speak for Opto-Engineering) is that they can also be used as very long stand-off borescopes. This allows for such things as inspection of pipe or cylinder IDs, or inner thread verification, without mechanical interference.

As for prices, ours are comparable to those of good telecentric lenses, and we have many models availble with sizes starting at just 55.9mm diameter.

Spencer Luster

John Salls said...

I am a bit in the same boat with you on this. When I first saw the lenses 2 years ago the Vision Geek in me said "That is just soooo cool. I gotta find an ap for it." And for 2 years I have been looking. I think I have just found the perfect application for the pericentric lens. Basically inspecting a label placement on a small cylinder. Of course using a line scan camera would be the "right" way to go, but we have to do this very quickly so that option is out. Just presented the pericentric option to my customer. My concern in this case is can we present the parts to the camera aligned upright so the camera can see all the way around it. Didn't even think about checking the price until I saw your article today. Sounds like I need to check in with Spencer, eh?

Anonymous said...

Pericentric and other 360° view lenses are used for a large variaty of vision inspection applications as a valid alternative to traditional approaches like multi-camera imaging or the rotation of the part. They make the system simpler from mechanical and software point of view and much more cost effective.

Pericentric lens gives top and side view of the object in one camera shot. The object diameter can be from 20 to 60 mm. The image can also be "unwrapped" by software in case the text recognition on label is needed.

Hole inspection lenses are used for imaging the inner walls and bottom of the holed object in perfect focus. There's no necessity to introduce it into the part and it may go from 10 mm to 100 mm diameters.

You may find lots of applications where these and many other 360° view lenses designed and manufactured by Opto Engineering are used: http://www.opto-engineering.com/search-by-applications.html

These are just some examples. Don't hesitate to contact me directly for an application discussion or any further information.

Alena Verameyeva
Senior Sales Engineer
Opto Engineering
alena.verameyeva@opto-engineering.com

Alena Verameyeva said...

Pericentric and other 360° view lenses are used for a large variaty of vision inspection applications and present a valid alternative to traditional approaches like multi-camera imaging or the rotation of the part. They make the system cost effective, smaller in dimensions and simpler in terms of software processing.

Pericentric lens enables top and side view of the object in one camera shot. The object diameter can be from 20 to 60 mm. It's possible to "unwrap" the image for a text recognition on side label.

Hole inspection lenses perform the inspection of cavities and image both inner walls and bottom in perfect focus. The lens is positioned outside the part and inspects the diameters ranging from 10 to 100 mm.

Check a great variaty of the applications done with 360° view lenses designed and manufactured by Opto Engineering: http://www.opto-engineering.com/search-by-applications.html

These are just some examples. Don't hesitate to contact me directly for an application discussion or any further information.

Alena Verameyeva
Senior Sales Engineer
Opto Engineering
alena.verameyeva@opto-engineering.com

Alena Verameyeva said...

Pericentric and other 360° view lenses are used for a large variaty of vision inspection applications and present a valid alternative to traditional approaches like multi-camera imaging or the rotation of the part. They make the system cost effective, smaller in dimensions and simpler in terms of software processing.

Pericentric lens enables top and side view of the object in one camera shot. The object diameter can be from 20 to 60 mm. It's possible to "unwrap" the image for a text recognition on side label.

Hole inspection lenses perform the inspection of cavities and image both inner walls and bottom in perfect focus. The lens is positioned outside the part and inspects the diameters ranging from 10 to 100 mm.

Check a great variaty of the applications done with 360° view lenses designed and manufactured by Opto Engineering: http://www.opto-engineering.com/search-by-applications.html

These are just some examples. Don't hesitate to contact me directly for an application discussion or any further information.

Alena Verameyeva
Senior Sales Engineer
Opto Engineering
alena.verameyeva@opto-engineering.com