I think this is an example of a decent patent - it's minor, but it's clever, non-obvious, and a clear improvement on the product, while not encroaching much on

I think this is an example of a decent patent - it's minor, but it's clever, non-obvious, and a clear improvement on the product, while not encroaching much on the solution space. You can still have a blinking light, or any of a handful of other solutions, just not a blinking light at a specific frequency.