In one of my posts last week, I noted that a featured patent included Jepson claims. Jepson claims are not dead (either "merely" or "really most sincerely"), but they may be on their way to extinction.
Jepson claims have been around since at least 1917. Such claims typically begin with a preamble of already-known elements ("In a system for making widgets with elements A, B and C"), then a transitional phrase ("..the improvement comprising..."), followed by the inventive elements presently claimed ("...elements D and E...") It has been said that in a Jepson claim, "the claim preamble defines not only the context of the claimed invention, but also its scope." Rowe v. Dror, 112 F.3d 473 (Fed. Cir. 1997).
Jepson claims bear some similarlity to Eurpoean claim forms that use "characterized by..." language. And like other claim forms, Jepson claims have their pros and cons. Wikipedia (admit it--you look there, too) actually gives a good summary, noting that Jepson claims can be useful in allowing the Examiner to hone in quickly on points of novelty, particularly in crowded arts. This could result in fewer Festo-inducing arguments and amendments. But the big downside, of course, is that there is an admission that the preamble's limitations are known in the art, and presumably (rebuttable) known by others for 103 purposes. See MPEP 2129. In a post-KSR world, where the apparently best obviousness attack is to show that an element is missing in the cited references, that doesn't leave much wiggle room.
It is not news that use of Jepson claims is atypical. Landis writes that "the occasion is rare when it is the recommended format" and that "It is seldom used in practice." Judge Newman echoed this thought over twenty years ago when she noted that the Jepson form of claim "occasionally continues to be used", and was thus an exception to "the modern style, [where] patent claims no longer merely claim the salient features, the 'heart' of the invention." Pennwalt Corp. v. Durand-Wayland Inc., 833 F.2d 931 (Fed. Cir. 1987) (en banc) (Newman, J., dissenting).
Less known, however, is that the use of Jepson claims has been dropping at a breathtaking rate. When Judge Newman made her comments, nearly 8,000 patents with Jepson claims were issuing annually. Today that number is closer to 1,000. The remarkable graph below represents the number of patents which include the word "improvement" in their claims, shown annually since 1976.
The law regarding Jepson claims has been pretty stable over this period, so the root cause of this drop-off is probably found elsewhere. Perhaps it was simply a natural process as new attorneys/agents entered the practice and opted to try claiming more broadly. Or perhaps there was a growing perception that courts were looking with increasing favor at broadly drafted claims. I'm not sure. But if you have a good theory--or a compelling argument why you think Jepson claims will/should have a big comeback--please share.
Anybody care to start a "Save the Jepson claim!" campaign on Facebook?
[UPDATE 6/4/09 1:56PM: The graph below shows the issuance of Jepson patents as a percentage of total issuances. Peak is over 14% (that's 1 in 7 patents, friends) in 1980, dropping steadily to about 0.7% in 2008]