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02-12-2010, 10:03 AM   #1
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Finding Lens Patents

Hello guys,

Does anyone know if lenses have to be listed with their patents? Like when you buy an electronic product, it lists the patents applicable to the product?

I do have a list of generic Pentax patents by searching a patent database, but because these patents are generic, I can't conclusively confirm if they are for a specific lens.

BUT on the other hand, if I find the patents listed for a specific lens (like in the product box or manual) then I could search for that patent in the database.

For exemple, the Pentax fisheye zoom patent, its a formula for fisheye zoom lens, but as it is a generic patent, it does not explicitly specifies 10mm - 17mm, so one could argue the DA 10-17 it is NOT a pentax design. But if i could find the patents in the actual product, i could verify who actually designed the optical formula.

Shouldnt lens also list their applicable patents? If they do, where is that listed?

And if the 10-17mm is actually Pentax, then the Tokina lens should ALSO have listed the patents for their 10-17, and this number should match the Pentax patent, correct?

Any help with this?

02-12-2010, 02:10 PM   #2
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I cant see a reason why a lens must have a list of applicable patents with it. If there is something unique enough about the design to patent then the manufacturer can list the patents and may do so but I don't think they have to.
Lens patents are generally for a specific type of optical design, not for a specific lens. For example the Pentax fisheye zoom patent you mentioned may be applicable to the 10-17mm but maybe they could re-optimise the design for a 9-16mm which would have the same layout but different elements and would come under the same patent.
Typically the patent would be for a type of lens design like a Tessar, Biotar, Triplet etc. These are fundamentally different designes but could each be optimised for different lenses. For example the Tessar is commonly available as a 50mm f2.8 but I also have a Tessar 600mm f/6 - the layout is the same but the exact lens properties are not.
I would be interested to see your list of pentax lens patents, maybe more conclusions could then be drawn.
02-12-2010, 03:20 PM   #3
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Original Poster

Taking the fisheye zoom as an example, I udnerstand the reason to patent generic optical solutions instead of specific patents. I agree with you.

But if that is the case, shouldn't the 10-17mm LIST somewhere, all the applicable patents??

And here is the link with some more info:

Google Translate

I am just confused why optical companies have all these patents listed for optical formulas, BUT lenses dont list the applicable patents...
02-13-2010, 05:44 AM   #4
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Probably because their only purpose is to provide a legal means of preventing other companies using the design without paying for it. Some equipment manufacturers like to list their applicable patents as a way of showing customers that their product is unique, I guess Pentax figured that their customers know their lens designes are unique. I agree though that it would be interesting to know which lenses are based on which patented designes.

Here are a few pentax lens related patent documents:
DA 50-135 f/2.8 espacenet — Bibliographic data
Pentax lens weather seal espacenet — Bibliographic data
Wide angle lens espacenet — Bibliographic data
Standard zoom (maybe 18-55?) espacenet — Bibliographic data


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