Simple Target Claiming

The main purpose of target claiming is to retain some measure of protection against infringement even if prior art comes to the fore that would invalidate the broadest claim. This can be readily appreciated using a Venn diagram. The scope of claim 1 covers the subject matter of the entire target, which includes rings a, b, c, and d. Claim 2 covers rings "a", "b", and "c", while claim 3 covers the inner rings "a" and "b", and claim 1 only covers the innermost ring "a". If invalidating prior art is discovered in ring c, then claims 1 and 2 would fall, but claims 3 and 4 have at least some chance of remaining valid.

Figure 36 — Simple Target Claiming

A second purpose of target claiming is to focus the patent attorney on alternatives to the preferred embodiment. Inventors have often spent a good deal of time and effort optimizing a working model of their invention. It is sometimes quite a stretch for them to focus on what is needed to make the invention work, rather than what is desired to make the invention work. Yet it is usually the duty of the patent attorney to claim as much subject matter as possible.

The key to effective target claiming is to choose the targeted parameter wisely. Ideally, the targeted parameter is one that captures the essence of the improvement over the prior art. In the above example the parameter was pH. In other claim sets the targeted parameter might be size, or duration, smoothness, or something else. In some instances it may also be necessary to claim a combination of parameters, especially where those parameters tend to run counter to each other. For example, it may be that an inventive battery is novel because it has a combination of both higher conductivity and thermal stability. In that instance the targeting would have to recite both elements. Claim 1 might recite "a solid polymer battery having a conductivity of at least [x], and cycle life of at least [y] cycles". (The x and y thresholds are given numbers here because exact numbers are irrelevant to the present discussion). Claims 2 and 3 might recite the same conductivity, but successively higher cycle life. Claims 4 and 5 might recite a higher conductivity, and the same successively higher cycle lives set forth in claims 2 and 3. Note that since a combination of two parameters is employed, a systematic targeting will likely require more claims than targeting of a single variable.

It should be apparent that a patent attorney could also use qualitative parameters to define the target. The only requirement is that the targeted parameter can be split into subsets. In a wine making patent for example, a process may be claimed in which an ingredient is added until the wine turns darker, with dependent claims reciting that the ingredient is added until the wine turns slightly darker, moderately darker, or considerably darker. Of course the terms "slightly", "considerably", and "moderately" should be defined in the Specification. By way of further example, a broad claim could be directed to a covering towards the tip of a catheter, with dependent claims reciting that the covering is applied near the tip and at the tip. In those instances the Specification needs to define "towards", "near", "at", as well as the term "tip".

Note also that the successively narrower claims can be set forth as independent claims, or as successive dependent claims. The use of dependent claiming structure is recommended for the reasons mentioned above.