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Assume there is an "original" patent on an invention and a subsequent inventor files a patent on an improvement to the original patent. If the "improvement" patent is granted, could the "original patent" prevent someone from using the "improvement" patent?

For example, could a patent on the square wheel (the "original patent") prevent the use of a round wheel patent (the "improvement patent)? Or could a round wheel patent (the "original" patent) prevent a rubberized-wheel patent (the "improvement")?

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Yes. And the answer is the same in the case of the improvement being patented or the impovement not being patented. The only issue is can you read a claim in the original patent as covering the improved version. Some improvements solve the problem a different way. Some improvements eleimate a part required in the original. In those cases the improved version, patented or not, might not fall under the claims of the original.

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The previous answer has all the components, but may be a bit confusing at the bottom line level. The bottom line is it depends. If the 'improved' patent still falls within the claims of the 'original' patent then the 'original' patent can exclude practice of the 'improved' one.

You may have to learn more about claims to get for yourself the answer to your specific case then.

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