## United States Court of Appeals for the Federal Circuit

04-1216, -1248

FREEDMAN SEATING COMPANY, Plaintiff-Cross Appellant,

v.

AMERICAN SEATING COMPANY and HI-TECH SEATING PRODUCTS, INC. (doing business as Kustom Fit), Defendants-Appellants.

Richard D. Harris , Greenberg Traurig, LLP, of Ch icago, Illinois, argued for plaintiff-cross appellant. Wi th him on the brief were Herbert H. Finn and Jeffrey P. Dunning

. Todd R. Dickinson , Fisher & Dickinson, of Ada, Michigan, argued for defendantsappellants. Of counsel on the brief were Conrad J. Clark and Christopher W. Brody , Clark & Brody, of Washington, DC. Appealed from: United States District Cour t for the Central Dis trict of California Judge R. Gary Klausner

## United States Court of Appeals for the Federal Circuit

04-1216, -1248 FREEDMAN SEATING COMPANY, Plaintiff-Cross Appellant,

v. AMERICAN SEATING COMPANY and HI-TECH SEATING PRODUCTS, INC ( doing business as Kustom Fit), Defendants-Appellants.

__________________________ DECIDED: August 11, 2005

__________________________ Before MAYER, Circuit Judge , PLAGER, Senior Circuit Judge , and SCHALL, Circuit Judge

. SCHALL, Circuit Judge

. This is a patent infringement case . Freedman Seating Company (“Freedman”) sued American Seating Company and Hi-Tech Seating Products (doing business as Kustom Fit) (collectively, “A merican Seating”) in the United States District Court for the Central District of California for infringem ent of U.S. Patent No. 5,492,389 (issued Feb. 20, 1996) (“the ’389 patent”) and for unfair competition in vi olation of the Lanham Act, 15 U.S.C. § 1125 (2000). The district cour t granted summary j udgment in favor of Freedman both on the iss ue of infringement under the do ctrine of equi valents and on American Seating’s counterclaim of inva lidity by reason of obviousness. Freedman Seating Co. v. Am. Seating Co. , No. CV-02-5347 (C.D. Cal. Oct. 24, 2003) (“ SummaryJudgment I ”). The court granted summary judgm ent in favor of American Seating, however, on Freedman’s Lanham Act claim. Id. After America n S eating filed a motion for reconsideration, the district court also granted summary judgment in favor of Freedman on American Seating’s affirmati ve defense of unenforceability based upon inequitable conduct. Freedman Seating Co. v. Am. Seating Co. , No. CV-02-5347 (C.D. Cal. Nov. 18, 2003) (“ Summary Judgment II ”). A jury trial subs equently was held to determine damages, the jury ultimately awardi ng Freedman $163,155.20 in lost profits from American Seating Comp any and $14,800.00 in royalt ies from Kustom Fit. Freedman Seating Co. v. Am. S eating Co. , No. CV-02-5347 (C.D. Cal. Jan. 12, 2004) (“ Judgment on Jury Verdict ”). American Seating now appeals all aspect s of the district court’s summary judgment decision that were unfavorable to it. Freedman, in turn, cross-appeals the district court’s ruling allowi ng American Seat ing to invok e the advic e of counsel defense to Freedman’s charge of willful infringement, the jury’s findi ng of no willful in fringement and its calculation of damages, and the distri ct court’s refusal to award costs and prejudgment interest. 1 Because we conclude that t he judgment of infringement under the doctrine of equiv a lents has t he effect of viti ating a limitation of the claims of the ’389 patent, we reverse the judgment and remand the case to t he district court wit h instructions to enter judgment of non-infringement in favo r of American Seating. Because we conclude that genuine issues of mate rial fact remain as to obviousness, we also revers e the district court’s grant of summary judgment of validity and remand for further proceedings. We do not reach the other issues raised on appeal.

1 Freedman does not appeal the distri ct court’s ruling on its Lanham Act claim.
04-1216, -1248 2BACKGROUND
I.
A. Freedman manufactures seats used in public transportation vehicles. Its product line includes stowable seats, whic h are seats that have the ability to fold away in order to create more interior space in a vehi cle. They are particularly useful for accommodating pass engers wit h w heelchairs, but may be used whenev er more interior space is needed. Freedman also owns the ’389 patent, titled “Stowable S eat.” The figures shown below are representative of the stowable seat clai med in the ’389 patent.

Figure 1 s hows the s t owable seat (10) in the horizont al (or deployed) posit ion, while figure 2 shows the stowable seat in the vert ical (or stowed) position. Moving the seat from its horizontal to vertical posit ion involves “folding the seatbac k (16) flat against the seatbase (14), unlocking the seatbase from its horizontally deployed position an d

04-1216, -1248 3raising the seatbase to its vertically stowed pos ition where it is locked in place.” ’389 patent, col. 1, ll. 19-24 (numerals added). As shown by figure 1, the invention of t he ’389 patent d oes not us e an ais l e leg to support the seat when in the horizontal pos ition. Se e id

. col. 1, ll. 8-14; col. 3, ll. 32-34. Rather, the invention is based on a cantilev e r design, which uses a diagonal truss (18), also referred to as a support member, to support t he aisle-end of the seat when in th e horizontal position. This des ign, according to the ’389 patent, avoids difficulties attendant with stowin g and deploying s eats that hav e a separate aisle leg. Id. c o l

. 1 , l l

. 25-35. In addition to providing aisle support, the diagonal truss allows for translational movement of the seat base between the horizontal and vertical po sitions. T h is is du e to the truss having a fixed end that is attached to the seat’s frame (12) at a pivot point (54), and a mov able end ( 56) that is “slidably mounted” in a runner track (58). Id. col. 3, ll. 40-47. When stowing the seat, the movable en d of the diagonal truss slides on the runner track toward the middle of the seatbase, while the fi xed end of the diagonal trus s rotates upward until the seat is in the vertic al position. Similarl y, when the seat is deploy ed again, the movable end of the diagonal truss slides toward the ais l e end of t he seatbase, while the fixed end rotates downwar d until the seat is in the horizonta l position. This folding me chanism created by the s lidab ly mounted moveable end is known in t he field of mechanical engineer ing as a “slider crank,” which is a particular type of “four bar mechanism.” Claim 1 is representative of the claims asserted agai nst American Seating; it reads:

04-1216, -1248 4A stowable seat for mountin g to support member of a vehicle wherein a space may be selectiv ely provided for positioning an article adjacent to the stowable s eat, when stowed the seat comprising: a frame attached to a support member; a cantilevered seatbase having a free end, a pivotable end including a pivot mounted theret o for rotatably associating said piv o table end wit h said frame and for providing said seatbase with a range of motion extending fro m a horizontally deployed position to a vertically stowed position, a support member for supporting said seatbas e in said deployed positi on inc l uding a moveable end slidabl y mounted to said seatbase and a fixed end journalled with said frame, and a first lock near said free end for releasably locking said movable end to maintain said seatbase in said deployed position; and a seatback having a pivot for rotatably associating said seatback with said seatbase and for providing said seatback with a range of mo tion extending from an unfolded position to a folded pos ition, said r ange of motion of said seatback being perpendicular to said range of motion of said seatbase, said seatback in said unfolded position adapted to be a pr edetermined angle with respect to said seatbase in said deployed position to provide seating and said seat back in said folded position adapted to be adjacent said seatbase for stowing to provide the space for the article. (Emphasis added).
B. American Seating Company and Kustom Fit also manufacture and market seating products for the transpo rtation industry. One particu lar s eat is the Horizon EZ Fold (“EZ Fold”), which is a stowable seat manufactured by Kustom Fit and sold b y American Seating Company. The EZ Fold is in m any respects similar, if not identical, to the invention claimed in the ’389 patent. Mo st notably , neither device has an ais l e leg. Howev e r, and important to this case, the tw o product s use different types of support

04-1216, -1248 5structures i n lieu of the aisle leg. The in vention claimed in the ’389 patent, of course, uses the slider crank, which is described in part by the “slidably mounted” limitation. The EZ Fold, on the other hand, uses w hat is known as a “fourth link.” Like the slider crank, the fourth link is al so a specific type of four bar mechanism. Howev e r, the two m e chanisms differ in t hat, where the moveabl e end of the ’389 patent’s support member is slidably mounted to the seatbase, the moveable end of the EZ Fold’s support member is rotatably m ounted to the seat base. Th erefore, the moveable end of the EZ Fold’s s upport member does not slid e or otherwise move along the seatbase. Rather, its only range of motion consists of rotation throughout it s revolute joints. That said, the EZ Fold ’s fourth link mechanism still provides the seatbase with fluid translational motion, and t hereby allows the s eat to fold between the deploy ed and stowed positions. It does t h is through an extra set of revolute joints located in the midsection of its support member (“mi d-joints ”). These mid-joints are shown be lo w in two representative illust ratio n s of the EZ Fold prod uct.

Mid-Joint s

The illustration on the left shows the seat in the fully deployed position, and the illustration on the right shows the device in transition between the deploy ed and stowed positions.

04-1216, -1248 6II. On July 5, 2002, Freedm an sued both Amer ican Seat ing Company and Kust om Fit for patent infringement and unfair competit ion under the Lanham Act. With respect to the claim for patent infringement, Freedman alleged that American Seating Company’s EZ Fold infringed the ’389 paten t. Freedman alleged that Kustom Fit also infringed as a result of its role in deve loping and manufacturi ng the EZ Fold f o r American Seating Company. In response to Freedman’s co mplaint, American Seating denied Freedman’s allegations of patent infringement and unf air competition, and also asserted a counterclaim of pat ent invalidity by reas on of obviousness. After some discovery, American Seating r equested leave to am end its ans w er. The district court granted this request on September 4, 2003, fo r the limited purpose of allowing American Seating to add an affirmative defense of unenforceability by reason of inequitable conduct. In due course, both parties filed motions for summary judgment on the issue of infringement. Freedman also moved for summa ry judgment of valid ity of the ’3 89 patent, and American Seating moved for summary judgment on Freedman’s unf a ir competition claim. With respect to the issu e of infringement, the c ourt stated that there really was no dispute as to claim constructi on or the structure of the accused product. Summary Judgment I , slip op. at 9. In fac t, the par ties generally agreed that the EZ Fold literally meets all of the limit ations of claim 1 exce pt fo r the limitation requiring that the movable end of the support member be “slidably m ounted” to the seatbas e

. Id. T h e accused pr oduct does not literally meet this limitation because the EZ Fold’s support member is rotatably m ounted, not slidably mounted, to the seatbase. Id. The district

04-1216, -1248 7court therefore identified the so le issue before it as “whether the ’389 Patent’s support member and movable end is equivalent to that found in the accused device.” Id. American Seating ar gued that its support member and mo veable end were not equivalent to the corre sponding s t ructure cl aimed by the ’389 patent because its system used a fourth link, which created a subst antially different support structure than the slider crank of the ’389 patent. Id. at 10. In particular, American Seating argued that the support structures of the two devices created substantia lly different distribution forces. The district court disagreed. As an initial matter, the c ourt stated that force distributions were not claimed in the ’3 89 patent and were t herefore of minim a l relevance. Id. at 11. In addition, the court found that any difference in force distributions was ins ubstantial, and that Freedman’s “slider-crank and [American Seating’s] fourth link perform substantially the same function in s ubstantially the same manner to achieve s ubstantia lly the same result.” Id. The court therefore granted Freedman summary judgment of in fringement by equivalence. Id. at 11-12. As to the issue of inv a lidity, Amer ican Seating oppos ed Freedm an’s motion for summary judgment on the ground that, at a minimum, there were genuine issues of material fact as to whether the invention of the ’389 patent was obvious. Again, the district court disagreed. The c o urt determi ned that the closest piec e of prior art, U.S

. Patent No. 5,489,141 (“the C.E. White refer ence”), which used an aisle leg, did not disclos e or otherwise teach a folding chair having a cantilever design. Id. at 7. Furthermore, while ot her prior art referenc es disclos ed cantilev e r designs, the court found that American Seating di d not “present information t hat clearly and convincingly demonstrates obvious ness of the ’389 Patent re sulting from the existenc e of ‘a reason,

04-1216, -1248 8suggestion, or motivati on in the prior art or elsewhere that would lead one o f ordinar y skill in the art to combine’” t he C.E. White reference wit h pr ior art cantilever d e signs. Id. at 8. Therefore, t he district court held that no reasonabl e juror could conc lude that the ’389 patent was invalid and, ac cordingly, granted Fr eedman s u mmary judgment of valid ity. Id. The court also seemed to reject American Sea t ing’s une n f orceabilit y defense, finding that the subject matter taught by the C.E. White reference was adequately disc losed in the Ba c k ground of the ’389 patent. Id. 2 Finally, the district court granted American Seating summary judgment on Freedman’s unfair competition claim. Id. at 12-13. American Seating subsequently sought reconsideration on the grounds that the district court had improperly granted summary judgment on the issue of validit y and had failed to c onsider American Seating’s a ffirmative defense of inequ itable conduct

. Freedman Seating Co. v. Am. Seating Co. , No. CV-02-5347, slip op. at 15-16 (C.D. Ca l. Nov. 13, 2003). The district court denied the mo tion with respect to the issue of validity, but granted the motion with resp ect to inequitable conduct. Id. at 5. Nevertheless, after the parties submitted addit ional briefing, the court granted Freedman summary judgment of no inequitable conduct. Summary Judgment II , slip op. at 5. Having concluded that Am erican Seating infr inged a v a lid and enfor ceable pat ent owned by Freedman, the district court held a jury trial to determi ne the amount of an y resulting damages. The jury c oncluded t hat Americ an Seating’s infringem ent was not willful and awarded Freedm an $177,955.20 in damages, $163,155.20 of which wa s

2 American Seating argued that the applic ants for the ’389 pat ent had engage d in inequ itable conduct during pros ecution by failin g to disclose to the examiner the C.E. White reference.
04-1216, -1248 9computed based on lost profit s from Ameri c an S eating Company, and $14,800 of whic h was based on a reasonable royalty from Kustom Fit. The di strict court subsequently denied Freedman’s request for c o sts and attor ney’s fees and ent er ed final j udgment. Judgment on Jury Verdict

. American Seating timely appealed to this court and Freedman has crossappealed. We have jurisdiction pu rsuant to 28 U.S.C. § 1295(a)(1). DISCUSSI ON In the main appeal, American Seating cont ends that the district court erred in granting summary jud g ment for Freedman on t he issues of infringement, validity, and enforceability. Freedman respo nds that the district c our t properly granted summary judgment on these issues. However, in its cross-appeal, Freedman contends that the district court committed severa l errors at the damages phas e of the litigation. In particular, Freedman contends t hat the dist rict court erred in allowing Am erican Seating to invoke the advice of counsel defense to the charge of willful infringement and in refusing to award cos t s and pre-judgment in terest. Freedman also contends that the jury’s finding of no willful infringement is not supported by substantial evidenc e and that the jury further erred by not awarding damages for all acts of infri ngement. 3 We begin by address i ng Am eric an Seating’s appeal, for if American Seating is not liable f o r patent infringement, there is no reason to consider Freedman’s crossappeal regarding dam ages.

3 As noted above, Freedman does not appeal the district court’s grant of summary judgment in favor of A m eric an Seating on the Lanham Act claim.
04-1216, -1248 10I. We review summary judgment decisions de novo , reapplying the standard used by the district court. Frank’s Casing Crew & Rental Too l s, Inc. v. Weatherfor d Int’l, Inc

. , 389 F.3d 1370, 137 6 (Fed. Cir. 2004); Ellis on v. Robertson , 357 F.3d 1072, 1075 (9th Cir. 2004). Under that standard, summary j udgment must be granted “if the pleadings, depositions , answers to interrogatories, and admiss i ons on file, together with the affidavits, if any, show that there i s no genuine issue as to any material fact and that the moving party is entitled to a j udgment as a matter of l a w.” Fed. R. Civ. P. 56(c). In other words, summary judgment must be grant ed if no “reasonable jury could return a verdict for the nonmoving party.” Anderson v. Liberty Lobby, Inc. , 477 U.S. 242, 248 (1986). In making this determination, “ [t]he evidence of the non-movant is to be believed, and all justifiable inferences are to be drawn in [the non-movant’s] favor.” Id.
at 255. II. Patent infringement is a tw o step inquiry. First, t he court must construe the asserted claim. RF Del., Inc. v. Pac. Keystone Techs. , Inc. , 326 F.3d 1255, 1266 (Fed. Cir. 2003). Second, the court must determi ne whether the accus ed product or proces s contains each limitation of the properly c onstrued claims, eit her literally or by a substantial equiv a lent. Id. The first step is a question of law; the se cond step is a question of fact. Id.
A. On appeal, American Seating contends that the district court’s grant of summary judgment of infringement had the effect of vi tiating the clai m limitation requiring that the

04-1216, -1248 11moveable end of the support mem ber be “slidably mounted to said seatbase.” That , according to American Seating, is because while the claim s of the ’389 patent unequivocally state that the mov eable end is “slidably m ounted,” the moveable end of the EZ Fold is rotatably mounted using revo lute joint s . In addit i on, American Seating argues tha t, at the ti me of filin g for the ’389 patent , the interchangea bility of four bar mechanism s was foreseeable to one of skill in the art. American Seating sta t es that thi s is significant becaus e, while F r eedman could hav e chosen to claim a fourth link mechanism (or even all types of four bar mechanism s), it chose to narrowly claim a slider-crank mechanis m . American Seating c ontends t hat competitor s should therefore be entitled to rely on this clear structural limitat ion without risk of i n fringement under the doctrine of equivalents

. American Seating further argues t hat, even if the district court’s finding of infringement would not vitiate the claim limitation, it presented evidence to the district court showing that the EZ Fold’s fo urth link is substantia lly different from the slider crank claimed in the ’389 patent. In respons e, Freedman contends that the district court proper ly granted sum m ary judgment of infringement. Freedman st ates that, contrary to American Seating’s assertions, the district court did not read “s lidably mounted” out of the claims. Rather, the district court merely concluded that t he rotatably mounted support member (or fourth link) of the accused product was equiv a lent to a s lidably mounted support member (or slider crank). Freedman asse rts that the district court reached this conclusion by properly applying the function-way-resu lt test for equivalence set forth in Graver Tank & Manufacturing Co. v. Linde Air Products Co. , 339 U.S. 605, 608 (1950). First, Freedman asserts that in both the accus ed product and the ’389 patent, mounting the

04-1216, -1248 12support member to the seatbase serves the f unction of attaching t h e moveable end of the support member to the seatbase while sti ll permitting the seatbase to move between the horizontal and ver t ical positions. Se cond, Freedman asserts that the ’389 patent and the accused product perform this function in the same way, by providing the movable end of the support member with bot h translational and rotational motion relative to t he seatbas e. Finally, Freedman asserts that both devices achiev e the same result, namely, “the repositioni ng of the movable end, from a fi rst position near the midpoint of the seatbase when the seatbase is stowed, to a position near the ais l e end of the seatbase when t he seatbase is deployed.”
B. Under the doctrine of equivalent s, “a produ ct or process that does not literally infringe upon the expr ess te rms of a patent claim may nonetheless be found to infringe if there is ‘equivalenc e’ bet ween the elements of the accused pr oduct or process and the claimed elements of the patented invention.” Warner-Jenkinson Co. v. Hilton Dav i s Chem. Co. , 520 U.S. 17, 21 (1997) (citing Graver Tank , 339 U.S. at 609). The doctrine evolved in recognition of the fact that [t]he language in the patent claims may not capture every nuance of the invention or descr ibe with complete precision the range of its novelty. If patents were always interpreted by their literal terms, their val ue would be greatly diminished. Unimportant and insubstantia l substitutes for certain elements could defeat the paten t, and its value to inv e ntors could be destroyed by simple acts of copying. Festo Cor p . v. Shok etsu Ki nzoku Kogyo Kabushiki Co. , 535 U.S. 722, 731 (2002); Graver Tank , 339 U.S. at 605 (“[T]o permit imitation of a patented invention which doe s not copy every literal detail would be to convert the prot ection of the patent grant into a

04-1216, -1248 13hollow and useless thing.”). At the same time, the doctrine of equivalents necessarily adds uncertainty to the scope of patent cl aims, and thereby detracts from the publicnotice function of patent claims and ri sks det erri ng non-inf r inging and potentially innovativ e endeavors. See Fes t o , 535 U. S. at 727 (“If the range of equivalents is unclear, competitors may be unable to det ermi ne what is a per mitted alternative to a patented invention and what is an infringing equivalent .”); Warner-Jenkinson , 520 U.S. at 29 (“There can be no denying that the doctri ne of equivalents, wh en ap plied broadly, conflicts with the definitiona l and public-notice functions of the statutory claiming requirements.”). In re cognition of this risk, and in an e ffort to strike the proper balanc e between protecting patentees whil e also providing sufficient no tice to the public, various rules of law have em erged to c onstrain when an d how the doc trine of equivalents is to be applied. Of relevance to this case is the “all limitations” rule. 4 The rule holds that an accused pr oduct or process is not infringing unless it contains each limitation of the claim, either literally or by an equivalent. See, e.g. , Warner-Jenkinson , 520 U.S at 29; Kustom Signals, Inc. v. Applied Concepts, Inc. , 264 F

. 3d 1326, 1333 (Fed. Cir. 2001). This princ i ple has two primary implications fo r the doctrine of equivalents. First, the all limitations rule requires that equivalence be assessed on a limitation- by-limitation basis, as opposed to from the perspective of the invention as a whole. Warner-Jenkinson , 520 U.S. at 29 (“Each elem ent cont ained in a patent claim is deem ed material to defining the scope of the patented inv ention, and thus the doc trine of equivalents must be applied t o

4 There are other constraints not relevant to this appeal, such as the doctrine of prosecution history estoppel, see generally Festo , 535 U.S. at 733-41, and the rule of subject matter dedication, see generally Johnson & Johnston Assocs. Inc. v. R.E. Serv. Co. , 285 F.3d 1046 (Fed. Cir. 2002) ( en banc ).
04-1216, -1248 14indiv i dual elements of t he claim, not to the in vention as a whole.”); Penn walt Corp. v. Durand-Wayland, Inc. , 833 F.2d 931, 935 (Fed. Cir. 1987) ( en banc ). Second, an element of an accused product or process is not, as a matter of la w, equiv a lent to a limitation of the claimed invent ion if such a finding would entir ely vitiate the limitation. Warner-Jenkinson , 520 U.S. at 29 (“It is important to ensure t hat the application of the doctrine [of equivalents], even as to an indi vidual element, is not allowed such broad play as to effectively eliminate that element in its entirety.”); Loc kheed Martin Corp. v. Space Sys ./Loral, Inc. , 324 F.3d 1308, 1321 (Fed. Cir

. 2003) (“[I]f a court determines that a finding of infringement under the doctrine of equivalents ‘would entirely vitiate a particular c l aim[ed] element,’ then the court s hould rule that there is no inf r ingement under the doctrine of equivalent s.” (citation omitted)); Bell Atl. Network Servs., Inc. v

. Covad Communications Group, Inc. , 262 F.3d 1258, 1279-80 (Fed. Cir. 2001) (same). There is no set formula for determining whether a finding of equivalence would vitiate a c l aim limitation, and ther eby violate t he all limitations rule. Rather, c ourts must consider t he totality of the circ umstances of each c a se and determine whether the alleged equivalent can be fairly characterized as an ins ubstantial change from the claimed subject matter without rendering t he pertinent limitat ion meaningless. See,
e.g. , Novartis Pharm. Corp. v. Abbott Labs. , 375 F.3d 1328, 1338 -39 (Fed. Cir. 2004) (“Permitting such an element in the accus ed product to come within the bounds of the claimed element would impe rmissibly extend the sc ope of the claim language beyond what the patentee actually claim ed.”); Moore U.S.A., Inc. v. Standard Regis t er Co. , 229 F.3d 1091, 1106 (Fed. Cir. 2000) (“If our case la w on the doctrine of equivalents makes anything clear, it is that all claim limitat ions are not entitled to an equal scope of

04-1216, -1248 15equivalents

. ”); Ethicon Endo-Surgery, Inc. v. U.S. Surgic al Corp. , 149 F.3d 1309, 1317- 21 (Fed. Cir. 1998) (indicating that asse ssing infringement under the doctrine of equivalents is dependent on the facts of eac h case); Sage Prods. , Inc. v. Devon Indus., Inc. , 126 F.3d 1420, 1425 (Fed. Cir. 1997) (“Becaus e th[e] issued patent contains clear structural limitations, the pub lic has a right to rely on t hose limits in conducting its business activities.”). Our decision in Eth i c o n provides a good example of the multi-factored analysis required by the doct r ine of equivalents. In that c a se, Ethic on Endo-Surgery, Inc. (“Ethicon”) sued U.S. Surgical Corp. (“U.S. Surgic al”) for infr ingement of claims 6 and 24 of U.S. Reissue Patent No. 34,519. 149 F.3d at 1311. T he patent related to surgical staplers and, specifically, a “lockout me chanism” used to prevent the user from discharging the stapler without first inserting a new staple cartridge. Id. The claimed lockout mechanism was located within the staple car t ridge and, in short, worked by blocking the stapler’s pus her bar from firing. See id. at 1313. Claims 6 and 24 differed in the specific location of the lockout me chanism. Claim 6 stated that the lockou t mechanism was “connected to . . . [the] longitu dinal slots” located in the cartridge, whereas in claim 24, the lockout mechanism was merely located s o mewhere in the path of the pusher bar. Id. The acc u s ed product did not lit erally infr inge claim 6 or claim 24, becaus e its lockout mechanism did not “obstruct the pusher bars’ path into the cartridge, but rather, prevent[ed] the bars from being pushed from behind by obstructing the movement of the cam bar retainers.” Id. In addition, “the [lockout mechani sm was] held out of the path of the pusher assembly . . . until just before the fi rst staple [was] fired. . . . [B]y the time

04-1216, -1248 16the first staple [was] fired, the [lockout mechanism was] in co ntact with the cam b a r retainer,” thereby prev enting a second firing. Id. Based on these differences, the district court concluded that there was, as a matter of la w, no infringement under the doctrine of equivalents , and t herefore granted U.S. Sur g ical summary judgment of noninfringement of both claim 6 and 24. Id. at 1314-15. On appeal, we affirmed summary judgment as to claim 6, but reversed the grant of summary judgment as to claim 24. Id. at 1321. With respect to claim 6, we agreed with the district court that the “connected to said longit udinal slots” limitation “ties the lockout mechanism to a specific place”—namel y, to the slots, which were loc a ted inside of the chamber. Id. at 1318 (citation omitted). In U.S. Surgical’s product, however, the lockout mechanism was “located at the dist al end of the [disposable loading unit,] nowhere near the longitudinal sl ots which [ w ere] located in the s t aple cartridge at the front end of the stapler.” Id. T herefore, because U.S. Su rgic al’s lockout mechanism was loc a ted outside of the cartridge and nowhere near t he longitudinal slots, we concluded that no reasonable juror could fi nd equivalence, i. e., an insubstantial difference. Id. at 1318-19. On the other hand, t he perti nent limitation of claim 24 merely stated tha t the lockout mechanism was located somewher e in the path of the pusher assembly, id. at 1312-13, and the accused product’s lockout me chanis m was located in the path of the pusher ass e mbly. However, there could be no literal infringement because, where the claimed lockout mechanism al ways “contact[ed] the [pusher assembly] ‘during staple firing,’” the accused produc t’s lockout mechanism “los [t] contact with the [pusher assembly] just prior to stapl e firing,” and then regained c ontact after firing, thereby

04-1216, -1248 17preventing a second firing. Id. at 1321. Nonethe less, we found that “this physic a l difference translates into a ‘very slight,’ ‘ver y quick’ temporal difference, a period that is perhaps as short as a few thousandths of a second.” Id. We further concluded that this subtle difference left genuine issues of mate rial fact as to infringement under the doctrine of equivalents. Id. at 1320-21. In doing so, we explained that our finding did not vitiate any limitati ons of claim 24 because the not ed difference “is a subtle difference in degree , not a clear, substantial difference or difference in kind , as was the case regarding c l aim 6.” Id. at 1321 (emphases added); see also Wright Med. Tech., Inc. v. Osteonics Corp. , 122 F.3d 1440, 1445 ( F ed. Cir. 1997) (holding that a finding of infringement under the doctrine of equiv a lents would not vitiate the “closely fit” and “extend through” limit ations of the asserted claims). Conversely , in Sage Products we affirmed the district court’s grant of summary judgment of non-infringem ent under the doctrine of equivalent s. 126 F.3d at 1421. One of the asserted patents described a container for discarding syringes and other lik e materials and claimed, among other things, “an elongat ed slot at the top of the container body” and a barrier means compris ed of “a first constriction ex tending over said s l ot.” Id. at 1422. We agreed that t he district court properly inte rpreted “top of the container body” to mean “highest poin t, level, or part of.” Id. at 1423. T he accuse d product differed from the claimed invent ion in that t he slot was located in the interior of the container rather than at t he top of the contai ner. Id. We concluded that finding infringement under these circumstances would vitiate the “slot at the top of the container body” and “extending over said slot” limitations. Id.
at 1424-26. We reached our conclusion bas ed on seve ral cons iderations, including the

04-1216, -1248 18simplic ity of the structure, the specif icit y and nar rowness o f the claim, and the foreseeability of variations at the ti me of filing the claim with the PTO: The claim at issue defines a re latively simple structural device. A skille d patent drafter would foresee the limiting potential of the “over said s l ot” limitation. No s ubtlety of language or complexity of the technology, nor anysubsequent change in the state of the art, such as laterdeveloped technology, obfuscat ed the significanc e of this limitation at the time of its inco rporation into t he claim. If [the patentee] desired broad patent pr otection for any container that performed a function similar to its claimed container, it could have sought claims with fewer structural encumbrances. . . . Instead, [the patentee] left the PT O with manifestly limited claims that it now seeks t o expand t h rough the doctrine of equivalents. Howev e r, as between the patentee who had a cl ear opportunity to negotiate br oader claims but did not do so, and the public at large, it is the patentee who must bear the cost of its failure to seek protection for this foreseeable alteration of its claimed structure. Id. at 1425 (citation and footnote omitted). Compar e Hughes Aircraft Co. v. United States , 140 F.3d 1470, 1475 (Fed. Cir. 1998) (“This is a case in which a ‘s ubseque n t change in the state of the art, such as later-devel oped technology, obf uscated the signific anc e of [the] limitation at the time of its incorpor ation into the claim.’”).
In Tronzo v

. Biomet, Inc. , 156 F.3d 1154 (Fed. Cir. 1998), we similarly conc luded that a finding of equiv a lence would vitiate t he claimed limitation. The asserted claims related to an artificial hip s o cket and included a limi tation requiring that the prosthesis’s body have “a generally conical outer surface.” Id. at 1156. In finding infringement, the jury concluded that the hemisph erical shape of the ac cus ed product’s hemis pherical cup was equiv alent to the “generally coni cal outer surface” limitation. Id. We reversed, finding no infringement as a matter of law. We were particularly troubled by expert testimony submitted by the plai ntiff, Tronzo, stating that “when either a hemispherical

04-1216, -1248 19cup or trapezoidal cup or any other shape cup is successfully implanted into the body, it functions almost exac tly the same way.” Id. at 1160 (emphasis in original). We stated that, according to this theory of infringement, “ any shape would be equivalent to the conical limitation.” Id. (emphasis added). “Such a result,” we concluded, “is impermissible under the a ll-elements rule of Warner-Jenkinson because it would write the ‘gener ally conical outer surface’ limitation out of the claims.” Id. ; see also Asyst Techs., Inc

. v. Em trak , Inc. , 402 F.3d 1188, 1195 (Fed. Cir. 2005) (holding that, under the “specific exc l usion” principle, “the term ‘mounted’ can fairly be sa id to specifically

exc l ude objects that are ‘unmounted’”); Moore U.S.A. , 229 F.3d at 1106 (“[T]o allo w what is undisputedly a minority (i.e., 47.8%) to be equivale nt to a majority w ould v i tiate the requirement that the ‘first and second longitudinal stri ps of adhesive . . . extend the majority of the lengths of said longitudinal marginal port i ons.’”). In the instant case, we think the district court’s finding of infringement under the doctrine of equivalents had the effect of entirely vitiating th e “slidably mounted” limitation. The parties agree t hat all of the claims require a supp ort member having “a moveable end slidably mount ed to” the seatbase. See, e.g. , ’389 patent, claim 1 & claim 5. 5 It is also not disputed that the mov eable end of the EZ F o ld ’s s upport member is rotatably mounted, not sli dably mounted, to t he seatbase. Therefore, while th e moveable end of the EZ Fold’s s upport member has the ability t o rotate, it cannot slide or otherwis e move along the s eat base. It is confined to a fi xed loc a tion. We think that this structural difference in the mounting of the moveable end to the seatbase is not a

5 Independent claim 16 uses slight ly dif f erent language—“a diagona l support member . . . i n cluding a moveable end slidably received by a lo ngit udinal guide member affixed to an underside of said seatbase”—but the parties do not argue that this difference is relevant to the disputed issue in the case.
04-1216, -1248 20“subtle difference in degree,” but rather, “a clear, substantial difference or difference in kind.” Ethicon , 149 F.3d at 1321. Freedman argues that the slider crank cl aimed in the ’389 patent and the fourth link mechanism used in the EZ Fold func tion in the same way to produc e identica l results. (Br. of Appellee at 17-21.) Fr eedman asserts that this is because “[b]oth the infringing seat and the claimed structure of the ’389 patent provide the moveable end of the support member with both translational and rotational motion relative to the seatbase.” ( Id. at 18.) The problem, however, is t hat taken to its logical conclus i on, Freedman’s argument would m ean that any support mem ber capable of allowing translational and rotational motion would be equivalent to a support member “slidably mounted to said seatbase,” which reads “s lidably mounted” completely out of the claims. This is the pr ecise ty pe of overextension of the doc trine of equiv a lents that the claim vitiation doctrine is intended to prev ent. Indeed, we rejected this same type of argument in Tronzo

. See 156 F.3d at 1160 ( holding that finding all s h apes to be equivalent structure w ould ent irely vitiation the limitat ion requiring a “generally conical shape” (emphasis added)). Freedman’s theory of infringement also s u ffe rs from some of the s a me problems we addres sed in Sage Product s . In particular, though elegant, the subject matter claimed by the ’389 patent involv es relatively simple and well-known technologies. The patentees also stated t hat they were aware of other ty pes of four bar mechanisms. ( See June 10, 2003 Dep. of Mich ael D. Moffa at 89-95; June 9, 2003 Dep. of Brian W. McClintock at 46-47.) Yet, they chose to spec ifica lly limit the claims to slider-crank mechanism s vis-à-vis the “slidably mounted” moveable end limitation. Members of the

04-1216, -1248 21public wer e therefore justifi ed in relying on this specif ic language in assessing t he bounds of the claim. Accordingl y, we think that to now say the claims inc l ude other four bar mechanisms under the doctrine of equivalents would unjustly undermine the reasonable expectations of the public. See Sage Prods. , 126 F.3d at 1425 (“Given a choice of imposing the higher costs of carefu l prosecut ion on patent ees, or imposing the costs of foreclosed business acti vity on the public at large, this court believes the costs are properly imposed on the group best posit ioned to determine whethe r or not a particular invention warrants investment at a higher level, that is, the patentees.”); see also Conopco, Inc. v. May Dep’t Stores Co. , 46 F.3d 1556, 1562 (Fed. Cir. 1994) (“The doctrine of equiv a lence cannot be used to er ase ‘me aningful structural and functional limitations of the claim on whic h the public is entitled to re ly in avoiding infringement.’” (citation omitted)). In sum, we hold that the district court’s finding of infringement entirely vitiated the “slidably mounted” lim itation of the ’389 patent. We therefor e reverse the court’s grant of summary judgment and remand with inst ructions to enter judgment of noninfringement in favor of American Seating.
III. Although we have now determined that Am erican Seating’s EZ Fold does not infringe the ’389 patent, we mus t neverthel ess addres s the invalidity counterclaim per the Supreme Court’s decision in Cardinal Chemical Co. v. Morton International, Inc. , 508 U.S. 83 (1993). 6 On appeal, American Seating ma ke s two primary arguments as to

6 On the other hand, we need not addre ss the issue of enforceability

. American Seating as serted that issue not as a counterclai m for a declaratory judgment, but rather, as an affirmative defense to Fr eedman’s charge of infri ngement. Therefore,
04-1216, -1248 22why the district court erred in gr anting Freedman summary judg ment of valid ity. First, American Seating c o ntends the district court applied an incorrect obvious nes s standard by equating obviousness with “indistinguis habl e.” Second, American Seating contend s that the district court im properly placed the burden of pr oving obviousness on America n Seating, the nonmoving party. As the nonmoving par ty, American Seating argues that it only needed to show the existence of genuine iss ues of material fact in order to defeat Freedman’s motion for summary judgment, a bu rden t hat Americ an Seating asserts to have satisfied. We agree with American Seating on both points. Although at times the dist rict court referred to the obviousness standard set forth
in Graham v. John Deere Co. , 383 U.S. 1, 17-18 (1966), at other times the court appeared t o equate obviousness wit h “indistinguishable .” Summary Judgment I , slip op. at 7 (“A patent is ‘obv ious,’ i.e., indist inguis hable, ‘if the differenc e between it and the prior art are such that the subject matter as a whole would hav e been obvious at t he time the invention was made to a person having or dinary skill in the art.’” (citation omitted)); id. (“Defendants have not provided eviden ce that demonstrates the ’389 Patent is obvious and indistinguishable from pr ior art.”). This not the correct perspectiv e from which to assess obviousness. Indeed, a claim that is obv ious is, by definition, “distinguis h able” from the prior art. See Graham , 383 U.S. at 17-18 (stati ng that an obvious nes s analysis requires, am ong other things, assessing the differences between the claimed invention and the pr ior art). The reason s u ch a c l aim is nonetheless invalid
(Cont’d. . . .) having concluded that American Seating does not infringe the ’389 patent, and having further directed the district court to ent er judgment of non-infringement, there is no reason for us to consider American Seating’ s affirmative defense, as it would have no effect on the scope of the judgment. See Ty peRight Keyboard Cor p . v. Microsoft Corp. , 374 F.3d 1151, 1156-57 (Fed. Cir. 2004).
04-1216, -1248 23is bec ause its differences over the prior art are simply not sufficient to warrant a patent grant. Therefore, the district court erred to the extent it he ld that t he ’389 pat ent could only be inv a lid for obviousness if indist inguis hable from the prior art. In addition, it appears that the di strict court erred by treating Am erican Seating, not Freedman, as the party moving for s u mma ry judgment. In particular, the court repeatedly stated that summa ry judgment for Freedman was appropriat e becaus e American Seating had fa iled to prove invalidity by c l ea r and convincing evidence. For example, the court stated: “In light of Defendants failure to prove invalidit y through obvious nes s or otherwise, this Court concludes that Plaintiff’s ’389 Patent is valid.” Summary Judgment I , slip op. at 8; see also id. at 7 (“Defendants have not provided evidenc e that demonstrates t he ’389 patent is obvious and in distinguishable from prior art.” ); id. at 8 (“Defendants do not present info rmati on that clearly and convinc i ngly demonstrates obviousness of t he ’389 Patent . . . .”); id. (“In sum, Defendants fail t o meet their burden of establishi ng validity.”). However, it was Freedman who moved for summary judgment. Therefore, American S eating only needed t o show the existence of a genuine issue of material fact in order to preclude s u mmary judgment for Freedman. Liberty Lobby , 477 U.S. at 252 (holding that once the moving party makes a prima faci e showing in support of its motion for summ ary judgment, the nonm oving party must come forward with ev idence sufficient to show a genuine issue of material fact). We think American Seating came fo rward with such evidence.

04-1216, -1248 24It is undisputed that the C.E. White reference disclosed all of the limitations of the claimed inv ention except for the cantilevered seatbase. (T he C.E. White reference used an ais l e leg instead of a cantilever.) However, Amer ican Seating pres ented evidence showing that cantilev e red seat s were in the prior art. ( See J une 10, 2003 Dep. of Michael D. Moffa at 89-95; June 9, 2003 D ep. of Brian W. McClintock at 46-47.) American Seating als o offered evidentiary support for its asse rtion that the inventio n of the ’38 9 p a t ent occurred on ly aft e r one of t he inv entors, Brian W. McClintock , was g i ven the specific assignm ent of modifying the C.E. White seat to elimin ate the ais l e leg. (June 9, 2003 De p. of Brian W. McClintock at 16-18.) We think that this record, although not clearly and convincingly demons trating obvious ness, was sufficient to create a genuine iss ue of material fact as to whether one of skill in the art would hav e been motiv a ted to combine the C.E. White reference with a s u it able c antilever devic e from the prior art. Accordingly, we reve rse the district cour t’s grant of Freedman’s motion for summary judgment of validit y and remand for further proceedings

. CONCLUS ION Because we hold that finding infr ingement under the doctr ine of equivalents would have the effect of vitiat ing the “slidably m ounted” limitation of the ’389 patent, we reverse the district court’s summary judgmen t of infringement in favor of Freedman and remand with instructions to enter judgment for American S eating of non-infringement. Because we hold that genuine i ssues of material fact exist as to obviousness, we reverse the district court’s grant of Freedman’s motion for summary judgment of validity and remand for further proceedings. Bas ed on our finding of non- infringement as a

04-1216, -1248 25matter of law, we do not reach Americ an Seating’s affirmative defense of unenforceability or the issues related to damages raised in Freedman’s cross-appeal. COSTS Each party shall bear its own costs.
R E VER SED and RE MANDE D

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