[BBear]

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?

[MattGunn]

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.

[BBear]

Matt,

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...

[MattGunn]

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