Let us for the moment ignore an anomalous class of claims that attempt to describe a device based on what it isn't, rather than based on what it is. For example, trying to claim a donut with reference to its hole. In these negative claim limitations, the world may be upside down -- adding something which is not supposed to be there may in fact defeat one of the patentee's required claim elements and therefore an allegation of literal infringement. For example, if a claimed donut specifically required a hole, and a competitor wanted to design around that patent, he might purposefully construct his product so that his version does not have a hole. But cases involving negative claim limitations are extremely rare.
In most cases, the answer is "no," you cannot add more features to your product (i.e., above and beyond what a patentee has claimed) in order to avoid a finding of infringement. This is because most claim preambles use the open transition term "comprising." "Comprising" means including all of the below-listed elements and possibly others as well. For example, suppose the patentee claimed his mousetrap as such:
A mousetrap comprising:
a spring;
a latch;
a mouse-trapping jaw;
and a trigger.
Now suppose a later inventor improves the combination by adding an audible alarm that sounds whenever the trap is sprung. The fact that the later inventor added an additional element will not defeat the original patentee's claim of infringement
Note that a different result would occur if the patentee used the transitional phrase "consisting of" rather than "comprising., for "consisting of" means the below-listed elements and no others. ("Consisting of" is infrequently used in U.S. patent law for this reason).
In most cases, the answer is "no," you cannot add more features to your product (i.e., above and beyond what a patentee has claimed) in order to avoid a finding of infringement. This is because most claim preambles use the open transition term "comprising." "Comprising" means including all of the below-listed elements and possibly others as well. For example, suppose the patentee claimed his mousetrap as such:
A mousetrap comprising:
a spring;
a latch;
a mouse-trapping jaw;
and a trigger.
Now suppose a later inventor improves the combination by adding an audible alarm that sounds whenever the trap is sprung. The fact that the later inventor added an additional element will not defeat the original patentee's claim of infringement
Note that a different result would occur if the patentee used the transitional phrase "consisting of" rather than "comprising., for "consisting of" means the below-listed elements and no others. ("Consisting of" is infrequently used in U.S. patent law for this reason).