MPEP 2144.05
Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions

This is the Ninth Edition of the MPEP, Revision 08.2017, Last Revised in January 2018

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2144.05    Obviousness of Similar and Overlapping Ranges, Amounts, and Proportions [R-08.2017]

See MPEP § 2131.03 for case law pertaining to rejections based on the anticipation of ranges under 35 U.S.C. 102 and 35 U.S.C. 102 /103.

I.    OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS

In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) (The prior art taught carbon monoxide concentrations of "about 1-5%" while the claim was limited to "more than 5%." The court held that "about 1-5%" allowed for concentrations slightly above 5% thus the ranges overlapped.); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997) (Claim reciting thickness of a protective layer as falling within a range of "50 to 100 Angstroms" considered prima facie obvious in view of prior art reference teaching that "for suitable protection, the thickness of the protective layer should be not less than about 10 nm [i.e., 100 Angstroms]." The court stated that "by stating that ‘suitable protection’ is provided if the protective layer is ‘about’ 100 Angstroms thick, [the prior art reference] directly teaches the use of a thickness within [applicant’s] claimed range.").

Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (Court held as proper a rejection of a claim directed to an alloy of "having 0.8% nickel, 0.3% molybdenum, up to 0.1% iron, balance titanium" as obvious over a reference disclosing alloys of 0.75% nickel, 0.25% molybdenum, balance titanium and 0.94% nickel, 0.31% molybdenum, balance titanium. "The proportions are so close that prima facie one skilled in the art would have expected them to have the same properties."). See also Warner-Jenkinson Co., Inc. v. Hilton Davis Chemical Co., 520 U.S. 17, 41 USPQ2d 1865 (1997) (under the doctrine of equivalents, a purification process using a pH of 5.0 could infringe a patented purification process requiring a pH of 6.0-9.0, explaining "[t]hat which infringes if later anticipates if earlier"); In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%); In re Waite, 168 F.2d 104, 108 (CCPA 1948); In re Scherl, 156 F.2d 72, 74-75 (CCPA 1946) (prior art showed an angle in a groove of up to 90° and an applicant claimed an angle of no less than 120°); In re Swenson, 132 F.2d 1020, 1022 (CCPA 1942); In re Bergen, 120 F.2d 329, 332 (CCPA 1941); In re Becket, 88 F.2d 684 (CCPA 1937) ("Where the component elements of alloys are the same, and where they approach so closely the same range of quantities as is here the case, it seems that there ought to be some noticeable difference in the qualities of the respective alloys."); In re Dreyfus, 73 F.2d 931, 934 (CCPA 1934); In re Lilienfeld, 67 F.2d 920, 924 (CCPA 1933)(the prior art teaching an alkali cellulose containing minimal amounts of water, found by the Examiner to be in the 5-8% range, the claims sought to be patented were to an alkali cellulose with varying higher ranges of water (e.g., "not substantially less than 13%," "not substantially below 17%," and "between about 13[%] and 20%"); K-Swiss Inc. v. Glide N Lock GmbH, 567 Fed. App'x 906 (Fed. Cir. 2014)(reversing the Board's decision, in an appeal of an inter partes reexamination proceeding, that certain claims were not prima facie obvious due to non-overlapping ranges); Gentiluomo v. Brunswick Bowling and Billiards Corp., 36 Fed. App'x 433 (Fed. Cir. 2002)(non-precedential)(disagreeing with argument that overlapping ranges were required to find a claim prima facie obvious).

"[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See also In re Harris, 409 F.3d 1339, 74 USPQ2d 1951 (Fed. Cir. 2005) (claimed alloy held obvious over prior art alloy that taught ranges of weight percentages overlapping, and in most instances completely encompassing, claimed ranges; furthermore, narrower ranges taught by reference overlapped all but one range in claimed invention). However, if the reference’s disclosed range is so broad as to encompass a very large number of possible distinct compositions, this might present a situation analogous to the obviousness of a species when the prior art broadly discloses a genus. Id. See also In re Baird, 16 F.3d 380, 29 USPQ2d 1550 (Fed. Cir. 1994); In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992); MPEP § 2144.08.

A range can be disclosed in multiple prior art references instead of in a single prior art reference depending on the specific facts of the case. Iron Grip Barbell Co., Inc. v. USA Sports, Inc., 392 F.3d 1317, 1322, 73 USPQ2d 1225, 1228 (Fed. Cir. 2004). The patent claim at issue was directed to a weight plate having 3 elongated openings that served as handles for transporting the weight plate. Multiple prior art patents each disclosed weight plates having 1, 2 or 4 elongated openings. 392 F.3d at 1319, 73 USPQ2d at 1226. The court stated that the claimed weight plate having 3 elongated openings fell within the "range" of the prior art and was thus presumed obvious. 392 F.3d at 1322, 73 USPQ2d at 1228. The court further stated that the "range" disclosed in multiple prior art patents is "a distinction without a difference" from previous range cases which involved a range disclosed in a single patent since the "prior art suggested that a larger number of elongated grips in the weight plates was beneficial… thus plainly suggesting that one skilled in the art look to the range appearing in the prior art." Id.

II.    ROUTINE OPTIMIZATION

A.    Optimization Within Prior Art Conditions or Through Routine Experimentation

Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.); see also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 ("The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages."); In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969) (Claimed elastomeric polyurethanes which fell within the broad scope of the references were held to be unpatentable thereover because, among other reasons, there was no evidence of the criticality of the claimed ranges of molecular weight or molar proportions.). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent"); In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions."). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) (identifying "the need for caution in granting a patent based on the combination of elements found in the prior art.").

B.    There is a Motivation to Optimize Result-Effective Variables

In In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), the CCPA held that a particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation, because "obvious to try" is not a valid rationale for an obviousness finding. In KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), the Supreme Court held that "obvious to try" was a valid rationale for an obviousness finding, for example, when there is a "design need" or "market demand" and there are a "finite number" of solutions. 550 U.S. at 421 ("The same constricted analysis led the Court of Appeals to conclude, in error, that a patent claim cannot be proved obvious merely by showing that the combination of elements was ‘[o]bvious to try.’... When there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense. In that instance the fact that a combination was obvious to try might show that it was obvious under §1.3."). Thus, after KSR, the presence of a known result-effective variable would be one, but not the only, motivation for a person of ordinary skill in the art to experiment to reach another workable product or process.

III.    REBUTTAL OF PRIMA FACIE CASE OF OBVIOUSNESS

A.    Showing That the Range Is Critical

Applicants can rebut a prima facie case of obviousness by showing the criticality of the range. "The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims.... In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range." In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See also Minerals Separation, Ltd. v. Hyde, 242 U.S. 261, 271 (1916) (a patent based on a change in the proportions of a prior product or process (changing from 4-10% oil to 1% oil) must be confined to the proportions that were shown to be critical (1%)); In re Scherl, 156 F.2d 72, 74-75, 70 USPQ 204, 205 (CCPA 1946) ("Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies."); In re Becket, 88 F.2d 684 (CCPA 1937) ("Where the component elements of alloys are the same, and where they approach so closely the same range of quantities as is here the case, it seems that there ought to be some noticeable difference in the qualities of the respective alloys."); In re Lilienfeld, 67 F.2d 920, 924 (CCPA 1933) ("It is well established that, while a change in the proportions of a combination shown to be old, such as is here involved, may be inventive, such changes must be critical as compared with the proportions used in the prior processes, producing a difference in kind rather than degree."); In re Wells, 56 F.2d 674, 675 (CCPA 1932) ("Changes in proportions of agents used in combinations... in order to be patentable, must be critical as compared with the proportions of the prior processes.").

See MPEP § 716.02 - § 716.02(g) for a discussion of criticality and unexpected results.

B.    Showing That the Prior Art Teaches Away

A prima facie case of obviousness may also be rebutted by showing that the art, in any material respect, teaches away from the claimed invention. In re Geisler, 116 F.3d 1465, 1471, 43 USPQ2d 1362, 1366 (Fed. Cir. 1997) (Applicant argued that the prior art taught away from use of a protective layer for a reflective article having a thickness within the claimed range of "50 to 100 Angstroms." Specifically, a patent to Zehender, which was relied upon to reject applicant’s claim, included a statement that the thickness of the protective layer "should be not less than about [100 Angstroms]." The court held that the patent did not teach away from the claimed invention. "Zehender suggests that there are benefits to be derived from keeping the protective layer as thin as possible, consistent with achieving adequate protection. A thinner coating reduces light absorption and minimizes manufacturing time and expense. Thus, while Zehender expresses a preference for a thicker protective layer of 200-300 Angstroms, at the same time it provides the motivation for one of ordinary skill in the art to focus on thickness levels at the bottom of Zehender’s ‘suitable’ range- about 100 Angstroms- and to explore thickness levels below that range. The statement in Zehender that ‘[i]n general, the thickness of the protective layer should be not less than about [100 Angstroms]’ falls far short of the kind of teaching that would discourage one of skill in the art from fabricating a protective layer of 100 Angstroms or less. [W]e are therefore ‘not convinced that there was a sufficient teaching away in the art to overcome [the] strong case of obviousness’ made out by Zehender."). See MPEP § 2145, subsection X.D., for a discussion of "teaching away" references.

Applicant can rebut a presumption of obviousness based on a claimed invention that falls within a prior art range by showing "(1) [t]hat the prior art taught away from the claimed invention...or (2) that there are new and unexpected results relative to the prior art." Iron Grip Barbell Co., Inc. v. USA Sports, Inc., 392 F.3d 1317, 1322, 73 USPQ2d 1225, 1228 (Fed. Cir. 2004). The court found that patentee offered neither evidence of teaching away of the prior art nor new and unexpected results of the claimed invention drawn to a weight plate having 3 elongated handle openings. 392 F.3d at 1323, 73 USPQ2d at 1229. The court then turned to considering substantial evidence of pertinent secondary factors such as commercial success, satisfaction of a long-felt need, and copying by others may also support patentability. Id. Nevertheless, the court found that Iron Grip failed to show evidence of commercial success, copying by others, or satisfaction of a long felt need for the following reasons: (A) Iron Grip’s licensing of its patent to three competitors was insufficient to show nexus between the "merits of the invention and the licenses," and thus did not establish secondary consideration of commercial success; (B) in response to Iron Grip’s argument that the competitor’s production of a three-hole plate is evidence of copying, the court stated that "[n]ot every competing product that falls within the scope of a patent is evidence of copying" since "[o]therwise every infringement suit would automatically confirm the nonobviousness of the patent;" and (C) although Iron Grip offered as evidence that the absence of the three-grip plate on the market prior to its patent showed that the invention was nonobviousness, the court stated that "[a]bsent a showing of a long-felt need or the failure of others, the mere passage of time without the claimed invention is not evidence of nonobviousness." 392 F.3d at 1324-25, 73 USPQ2d at 1229-30.