Don’t like having your own inventions used against you? Before your patent issues, consider filing a continuation application.
Just got your US patent application allowed? Congratulations! Now before it issues (usually about 2-4 months after you pay the issue fee), you need to decide if you ever will want to file any improvements or variations of that invention in the future.
If you do have some improvements or variations in mind, now is the time to start working on filing a “continuation-in-part” (or CIP). In a CIP, you are basically telling the USPTO that you have added some new concepts to your original patent application. This is OK – worst case the examiner may determine that the new concepts have a later filing date, but in any event, the examiner won’t hold your original patent application against you.
In contrast to a CIP, patent continuation applications are essentially a repeat of the original application. Any differences to the claims had better be fully disclosed in the original application.
Why file a continuation? One common reason is that you think that you may be able to get stronger claims the second time around, perhaps by making the claims shorter and hence stronger. Or perhaps there was something in the original application that you forgot to put into your original claims. Both types of claim changes are fine so long as you can show that the newer claims were fully disclosed in the original application.
A second common reason is a nagging fear that although you might not have thought of any improvements or variations yet, you can’t rule out the possibility that you might do so in the near future. Here, if you don’t file a continuation, after your patent issues, your own patent will be used against your later patent applications as if someone else had invented it.
However if you do file a continuation, it essentially keeps your original patent “alive” a while longer (usually at least another year or so). Then, if you do come up with an improvement, you can then file a CIP to your continuation application. When you use this strategy, the USPTO will allow you to claim your later improvement without using your original application against you.