Looking for a sensor to detect a spot on a clean fabric sheet

Hi,
I have a bed sheet ironer and want to install some kind of sensor to detect dirty sheets so that those can be dropped (and separated)
during the process. The sheet colors are white or beige and the spots are gray or somthing close to black.
Thanks,
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Tom, Erwin Sick www.sick.de make a wide range of sensors especially for your application - I wouldn't bother with anything else.
You probably want a Contrast Scanner rather than a straight Colour Sensor - maybe something simple like their ST130 range. These things can detect the difference between a dark pencil mark and a black pen mark and are very impressive in use.
HTH, Cameron:-)
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On 7 Jun 2004 14:11:27 -0700, snipped-for-privacy@yahoo.com (Tom) wrote:

Sounds difficult - a large area to cover unless you can arrange some form of scanning - a vision system might be more appropriate.
Try
www.keyence.com

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