P� 21. okt. 2004 kl. 23.13 skrev P�l Jensen:
Alan wrote:
I was wondering if this patient thing was accurate (I really don't know,
that's why I ask). Did Pentax hold the "major" patients, or just a mnor part
of it? Were Canon & Nikon using Pentax "IS/VR" technology"? Or are we just
trying to make us Pentaxens felt better? I have never heard or read the same
suggestion anywhere else outside PDML. Any direct link to any creditable
source to prove this suggestion?
The patents in question are from 1989-1991 if my memory serves me right. They are Pentax patents on the complete optical designs in every minute detail for telephoto IS lenses and another patent for IS telephoto zoom lenses. These Pentax patents only refer to other companies patents on the servo mechanism and an early Canon patent that outlines the principal design of an IS lens (this contains only a few lens elements that only outlines what types of elemnst needed i such a lens like eg. moving elements, correcting elements etc.). All subsequent Canon and Nikon patents refers to these Pentax patents and I can find no patent older that the Pentax ones on workable optical designs. I could find no Canon patents that predate the Pentax ones on finished optical designs and again the subsequent Canon patents on IS all refer to these Pentax patents.
The patents are no longer available through the net unless you pay for them but they were once posted on the PDML.
The last sentence can�t be correct. The availability of patent specifications have been increasing the last few years. You could try such databases as:
http://ep.espacenet.com/
and
http://www.uspto.gov/patft/index.html
I would be very interested if you could refer to any patent numbers.
DagT
