On Fri, 7 Aug 2015, EBo wrote: > Date: Fri, 07 Aug 2015 17:13:25 -0600 > From: EBo <e...@sandien.com> > Reply-To: EMC developers <emc-developers@lists.sourceforge.net> > To: emc-developers@lists.sourceforge.net > Subject: Re: [Emc-developers] research on optical encoders > > On Aug 7 2015 4:16 PM, andy pugh wrote: >> On 7 August 2015 at 12:23, EBo <e...@sandien.com> wrote: >>> Possibly, but I cannot tell from the information Renishaw published >>> in >>> that brochure. >> >> I think that the target is a barcode. The head can see enough barcode >> to tell exactly where it is on the code sequence to within one bar, >> then looks at the absolute position of the bars in the viewing area >> to work out the rest of the bits of data. > > I think it is following on the same idea roughly. Looking at the > renshaw they claim it can give you 1nm (1e-9m) or 3.9e-8 inches > precision. I have no idea how they are pulling that off besides laser > interferometry and ring counting. Can you suggest another method that > would work?
AFAIK they dont use a laser, just a bright LED thats pulsed to take a snapshot of the barcode, probably with a rather high resolution linear sensor array (or multiple arrays with pixel interleaving) Quite high-sub pixel interpolation should possible with such a setup because of all the duplicated edges > > > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
