Patent Attorney and Founder
It sounds like you’re looking at two patents:
one old and expired, and one that came later.
The first one was broad. It covered using a long pulse and a short pulse to make a device do something. No timing details. No numbers. Just the idea.
The newer patent used the same idea, but added a twist. It claimed the same long pulse and short pulse, but the short pulse had to be five microseconds or less. That’s the only real difference.
So the big question is:
Should that newer claim have been allowed? And could the owner of the new patent stop someone from using what the old patent already taught?
Here’s the simple way to think about it.
The patent office keeps records of every back-and-forth conversation between the inventor and the examiner. That’s the prosecution history, and it’s all public. If the older patent was that close, the examiner likely brought it up. They usually do when something overlaps.
From there, the inventor of the newer patent would’ve had to argue that the five-microsecond limit wasn’t obvious. Maybe most people in the field used much longer pulses. Maybe no one could reliably make a pulse that short at the time. Something like that. They would’ve needed a reason that the shorter pulse wasn’t just a small tweak anyone could think of.
Could it also depend on what the device is used for?
Yes. Sometimes two inventions use the same idea, but for different things, like using one pulse setup for laser hair removal and another for image sensors. Same tool, different job. That can matter.
But here’s the key point:
- A new patent can only stand if the “five microseconds or less” part adds something non-obvious.
- The owner of the new patent cannot block anyone from doing what the old, expired patent already disclosed. Once a patent expires, the public can use whatever it taught.
If the newer claim still covers something that was already described in the older patent, it could be challenged and possibly knocked out.
Great question. These edge-case timing claims can get messy, but the heart of it is always: “Was the new part truly non-obvious?”