I'm considering making a game that uses patent illustrations (from Context-Free Patent Art) as graphics. I've read the answers to Are text and images in the patent copyrighted?, which suggests that if a graphic is not explicitly copyrighted, it can be freely reproduced. However, I have some concerns:
- When looking at the original patent, is the lack of a copyright notice in the patent sufficient to make sure the images in it are not copyrighted? This would seem to violate the Berne convention.
- The game would be accessible across the world, not just in the US. How does this complicate things? Is it possible/likely that a challenge could be brought against the game in a non-US court?
- I assume that I have to check that the images aren't trademarked.
What I'm looking for is a test I can apply to patent images to see if they are reasonably safe for me to use in a game. The game design doesn't rely on any specific images being available, as long as some are safe to use.