Re: more patents on interval arithmetic implementations
> Date: Tue, 30 Dec 2008 09:12:25 +0100
> From: Arnold Neumaier <Arnold.Neumaier@xxxxxxxxxxxx>
> To: Dan Zuras Intervals <intervals08@xxxxxxxxxxxxxx>
> CC: Ulrich Kulisch <Ulrich.Kulisch@xxxxxxxxxxx>, Bob.Davis@xxxxxxx,
> 1788 <stds-1788@xxxxxxxxxxxxxxxxx>,
> interval <reliable_computing@xxxxxxxxxxxxxxxxxxxxxx>, m.zaman@xxxxxxxx
> Subject: Re: more patents on interval arithmetic implementations
>
> Dan Zuras Intervals schrieb:
> >> Date: Mon, 29 Dec 2008 12:27:34 +0100
> >> From: Ulrich Kulisch <Ulrich.Kulisch@xxxxxxxxxxx>
> >>> Arnold Neumaier schrieb:
> >>>
> >>> Several old patents, two by Kulisch, one by Miranker, and one by Rump,
> >>> are related to items 2 and 3 (accurate sum and inner product) in
> >>> Section 5.1 of the Vienna proposal:
> >>>
> >>> - Circuitry for generating sums, especially scalar products
> >>> http://www.patentstorm.us/patents/4866653/fulltext.html
> >>>
> >>> - Circuitry for generating scalar products and sums of floating point
> >>> numbers with maximum accuracy
> >>> http://www.patentstorm.us/patents/4622650/fulltext.html
> >>>
> >>> - Systolic super summation device
> >>> http://www.patentstorm.us/patents/4751665/fulltext.html
> >>>
> >>> - Method and circuit arrangement for adding floating point numbers
> >>> http://www.patentstorm.us/patents/4866651/fulltext.html
> >>>
> >> As far as I understand the matter all these patents provide hardware
> >> circuitries to compute sums and dot procducts of floating-point numbers
> >> exactly. They have been filed more than 20 years ago and thus should all
> >> be expired.
> >
> > These are relevant to us in that, being expired patents,
> > the methods described should never be patented again.
>
> How is the life-time of a patent determined?
>
>
> Arnold Neumaier
>
In the U.S. up until recently the answer was 17 years from the
date the patent was issued (always on a Tuesday). A few years
ago the law was changed to make it 20 years from the date the
patent was filed with the USPTO. Someone else will have to
answer for other countries. - Dan