The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "Adrian M Jansen"
Subject: Re: Detecting colored objects
X-Newsreader: Microsoft Outlook Express 5.00.2919.6600
Date: Thu, 31 Oct 2002 10:04:32 +1000
NNTP-Posting-Date: Thu, 31 Oct 2002 11:02:41 EST
Organization: Telstra BigPond Internet Services (http://www.bigpond.com)
But for multiple colors you still need some way of switching the color
target for each color. Seems this would have to be mechanical, and hence
fairly slow. Switching vari-color light sources on and off, and measuring
response can be at electronic speeds.
Adrian Jansen email@example.com
Design Engineer J & K Micro Systems
Microcomputer solutions for industrial control
"Keith Buck" wrote in message
> This problem was literally sorted out years ago, yet no-one seems to have
> heard of the solution. You need a single photomultiplier tube and a lens
> with a white light source also. For every colour that you need to detect,
> you also need a sample of the same colour as a piece of card or painted
> metal. This is arranged to fill the PM tubes field of view. The object to
> detected is then placed in front of the coloured card. If it is identical,
> then it will not be detected as it will be identical to the background.
> however if it is only slightly different in hue or saturation, then the PM
> tube signal will change in one directin or another. You need some support
> electronics for the PM tube and amplifiers etc and a presence detector for
> the object.
> Regards Keith Buck
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup