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  • Description:
    English: Image from 1928 US patent 1,657,411 ( Enigma machine) by Arthur Scherbius (died 1929).
May or may not be in the public domain In general, the contents of United States patents published before March 1, 1989 are in the public domain.

In specific cases, patent applicants and holders may claim copyright in portions of those documents. In those specific cases, applicants are required to identify the portions that are protected under copyright, and are additionally required to state the following within the body of the application and patent:

A portion of the disclosure of this patent document contains material which is subject to (copyright or mask work) protection. The (copyright or mask work) owner has no objection to the facsimile reproduction by any­one of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all (copyright or mask work) rights whatsoever.

The original patent should be checked for the presence of such language before an assumption is made that the contents are in the public domain. (This template can be replaced by {{ PD-US-patent-no notice}} in such cases.)

Note: This only applies to images published before March 1, 1989. Patents published after that date are most likely copyrighted, unless in the public domain for another reason, such as {{ PD-ineligible}}.

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