dissenting.
I respectfully dissent.
The majority reversed the district court’s holding on anticipation and affirmed the district court’s holding regarding nonobviousness. I disagree with the majority on both issues.
Anticipation
On the question of anticipation, the district court stated:
The Dirks system * * * is the Cole system implemented in 1940’s digital technology, and, since the Cole claims are drawn to cover all digital systems generically, as opposed to a new implementation, they are anticipated by these foreign Dirks’ patents. [558 F.Supp. at 945, 217 USPQ at 426.]
sj: sjc * &
Thus, while the claims in suit must be read in the context of the specifications, they may not be read as limited to the implementation which they disclose. [558 F.Supp. at 945, 217 USPQ at 426.] * * * * * *
The Cole invention was not a specific device; it was a system concept for direct production of digital video bits from coded data and was operable when appropriately implemented by those skilled in the art * * *. The Dirks patents disclosed the same concept of converting coded data directly into pulse trains representing the appropriate characters, timed and arranged by character slices for display in a television type raster scan pattern. Like Cole, the Dirks concept was operable when properly imple*1449mented by those skilled in the art. F.Supp. at 950, 217 USPQ at 429.] [558
The issue of anticipation, under 35 U.S.C. § 102, is an issue of fact which is reviewable on appeal under the “clearly erroneous” standard of Rule 52(a), Fed.R.Civ.P. Kalman v. Kimberly-Clark Corp., 713 F.2d 760, 771, 218 USPQ 781, 789 (Fed.Cir.1983). Thus, a reversal can be predicated only upon a “definite and firm conviction that a mistake has been committed.” United States v. United States Gypsum Co., 333 U.S. 364, 395, 68 S.Ct. 525, 542, 92 L.Ed. 746 (1948). I believe the district court’s holding on anticipation is completely supported by the record and by the extensive and detailed findings in its opinion.
As found by the district court, the Cole specification disclosed a system for computer generated digital data and did not disclose any specific structure for implementing the system. The Cole specification disclosed the system solely in terms of the functions to be performed. Thus, I disagree with the majority’s holding that the district court erroneously equated the yokes of Dirks to the position counts means of Cole.
The district court’s finding that Cole’s position counts means was anticipated by Dirks is supported by the evidence. Since Cole’s drawings disclosed the invention in functional block diagrams and his specification was neither explicit nor limited as to the contents of these blocks, the position counts means and the yokes were equivalents of one another. In Tate Engineering, Inc. v. United States, 477 F.2d 1336, 1342, 193 Ct.Cl. 1088, 175 USPQ 115, 119 (1973), the Court of Claims stated: “To anticipate, a prior art reference must disclose each and every element of a claimed combination, or its equivalents, and the element must function in substantially the same way to produce substantially the same result.” (Emphasis added.) Since the components of the Dirks system are of a 1940’s vintage and those of the Cole system are not specified, the elemental blocks corresponding to the claimed elements in Cole are equivalents of the components of Dirks.
The majority’s reliance on Kalman, supra, is without merit because in that ease equivalency was not at issue. In the present case, equivalency is a major consideration which was raised at trial and in this appeal and it must be dealt with in this appeal. Otherwise, it would be erroneous and contrary to Tate Engineering. Since Kalman did not overrule Tate Engineering, Tate Engineering must be followed unless overruled en banc. Tate Engineering was a per curiam opinion by seven judges of the then United States Court of Claims, six of whom are still active on this court, including the writer of this dissent. Majority’s summary overruling of Tate Engineering is contrary to this court’s basic rules of decision making as adopted in South Corp. v. United States, 690 F.2d 1368, 215 USPQ 657 (Fed.Cir.1982).1 Similarly, majority’s reliance on In re Mott, 557 F.2d 266, 194 USPQ 305 (CCPA 1977), is inapposite since the anticipatory reference, Dirks, discloses a structure, the yokes, that is capable of performing the functional limitation claimed in Cole.
The district court’s anticipation finding is also buttressed by the fact that the two systems are functionally identical. Both systems generate dot-position counts during a scan of the beam through a character space, and apply them to the column elements of the translator matrix. In Cole, they are generated by unspecified compo*1450nents in a timing and control unit and applied to column conductors 55 to 59 of the digital-to-video generator. In Dirks, dot-position counts are generated by yokes 71° to 719 and applied to the column cores such as cores 0 to 9 in matrix 50. Both systems count off positions at the respective matrix columns and cause a pulse or no-pulse to be applied serially to the CRT as the CRT beam scans the successive dot positions across the character space. In the Dirks system, the position of each yoke 71 tracks, and indicates the count of, the dot position of the scan, and performs the same sequential energization function as the Cole position counts. In this regard, the district court found:
The magnetic yokes 71° to 719 all move in unison, to scan the respective matrices 50 to 59, the successive dot positions of each matrix being scanned as the beam scans across a character space on the screen.
!j! S-C ¡k t- * *
As the yoke 71° then scans the matrix rows 50° to 509, in synchronism with the beam scan of positions 0 to 9 across a character space, with switch 46 in its leftmost position, the top slice of the “0” will appear as bright dots at positions 3, 4, 5 and 6 across the character space. [558 F.Supp. at 947, 217 USPQ at 427.]
The district court’s finding is further supported by evidence in the record. For example, Mr. Seligsohn, the RCA patent attorney who prepared most of the Cole claims and participated in the licensing of the Cole patent, testified that the term “position counts” merely signifies that the video signal must be a serial string of on/off pulses for the successive positions across a character space. This capability is clearly present in both the Dirks and Cole systems. In this regard, Mr. Seligsohn testified:
It is my understanding that if you are going to produce a video signal for use on a television raster scan where * * * there is an electron beam, a single electron beam essentially, a one point that is moving, that you must apply a serial signal to that * * * because the beam has to be turned on and off at the proper point when that electron beam is at that point.
So now you are suggesting that somehow you can get that without position counts, which are the serial on and off positions.
Now, I don’t see that you can do that * * * I say that if you are going to do it this way, then you have got to have position pulses in a serial form at the output.
I next disagree with the majority that Dirks cannot be an anticipatory reference since the yokes served as outputs of the matrices and not as inputs as required by Cole’s claim 1. In essence, the majority believes that the position counts means must be an input to a character generator. This configuration, however, is not supported by the claims of Cole. In the Cole claims, there is neither a recitation of a character generator nor an indication of the exact relationship of position counts vis-a-vis the inputs of a character generator. Cole’s claim 1 recites only (in element 4) that the position counts contribute to the supply of a video signal to the display device. More important, however, is that the configuration disclosed in Dirks amply supports the district court’s finding that the yokes are inputs. Each matrix’s output signal to the screen is the result of the combined action of three signals — the character code, the scan-line count, and the position count. In operation, the primary windings of each matrix are energized by the character code and the scan-line count signals, respectively. After the closure of the matrix’s core by the position count signal of a yoke 71, the secondary winding of the matrix produces the output signal. Thus, yoke 71 clearly serves as an input. Professor Ward, an expert witness in behalf of RCA, testified that “whether the screen [at] each point is bright or not bright, is dependent upon three inputs in the Dirks system, one being the character input to one of the matrices, the other being the scan-line input, and the other being the position of the yoke [i.e., position *1451count] along the matrix.” (Emphasis added.)
Last, the majority held that Dirks failed to disclose digitally generated signals as required by Cole’s claim 2. The district court, however, stated:
RCA and its expert read the word “digital” more narrowly than did artisans of ordinary skill in the art in the early 60’s.
The character generator of the Dirk system can produce only on/off signals, for each successive pulse position of the video pulse train. There is no value significance to any voltage derived from a Dirks core matrix until the voltage reaches a level to produce a pulse at the output of amplifier 72 in Figure 2a. Anything above that level produces an output pulse; anything below it does not.
This is purely digital operation. [558 F.Supp. at 949, 217 USPQ at 428-29.] I believe the district court’s finding in relation to anticipation was not clearly erroneous.
Obviousness
Assuming arguendo that the district court’s ruling on anticipation was incorrect, I would vacate the obviousness holding and remand to the district court in light of the fact that the district court’s determination on this issue was flawed. From the district court’s opinion, it is difficult to discern whether the district judge considered the Dirks patent in his obviousness determination. With the exception of two footnote references to the Dirks patent, the district judge’s obviousness determination was based on an analysis of the Evans, Jones, and Gordon patents.
Contrary to the majority’s statement that there was “no error in the district court’s thorough and sound analysis following the tenets set forth in Graham * * * ”, I believe that the district court’s factfinding regarding the “differences” criterion set forth in Graham was clearly erroneous.
Where, as here, the obviousness of an invention is at issue, the Supreme Court has clearly mandated factfindings on each of the three factors stated in Graham. A district court must make such factfindings “in such detail and exactness as the nature of the case permits * * * on which the ultimate conclusion * * * can rationally be predicated.” Kelley v. Everglades Drainage District, 319 U.S. 415, 420, 63 S.Ct. 1141, 1144, 87 L.Ed. 1485 (1943); see United States v. Morow, 182 F.2d 986 (D.C.Cir. 1950) (findings were not sufficiently comprehensive to warrant affirming the district court’s judgment). These factfindings are necessary “to disclose to the reviewing court the steps by which the trial court reached its ultimate conclusion * * Denofre v. Transportation Insurance Rating Bureau, 532 F.2d 43, 45 (7th Cir. 1976). See generally Golf City, Inc. v. Wilson Sporting Goods Co., 555 F.2d 426 (7th Cir. 1977). Generally, a reversal and a remand are warranted when the district court’s factfindings are ambiguous, contradictory, incomplete, or insufficient to establish a satisfactory basis for a decision. The E.A. Packer, 140 U.S. 360, 11 S.Ct. 794, 35 L.Ed. 453 (1891). In particular, it is reversible error when factfindings fail to provide an appellate court with a clear understanding of the basis of the district court’s obviousness determination. See Golf City, 555 F.2d at 434; United Shoe Machinery Corp. v. Kamborian, 160 F.2d 461, 465, 73 USPQ 1, 5 (1st Cir.1947).
Although the district court recognized that appellees relied on Dirks as well as the other references in their obviousness argument, it failed to take Dirks into consideration in its analysis.2 Instead, the district court focused on the Evans, Jones and Gordon patents, and only mentioned Dirks in two footnotes. In his discussion captioned “Comparison of Cole With the Prior Art And The Obviousness,” 558 F.Supp. at 952, 217 USPQ at 431, the district judge stated:
*1452The primary Section 103 issue15 presented by the parties is whether it would have been obvious to one of ordinary skill in the art in October of 1963 * * * to combine Jones or Gordon with Evans in such a way as to produce the concept claimed in Cole. While the fact that the Examiner apparently did not consider a prior art patent disclosing a digital character generator deprives the Cole patent of its presumption of validity, I nevertheless conclude that Cole is not obvious based on Evans in light of Jones or Gordon.
Footnote 6 merely states:
6 The use of both sawtooth and staircase (or stepping) waveforms for vertical and horizontal deflection in CRTs was common prior to 1960, as evidenced by the Brown and Gordon patents. * * * It was a matter of designers’ choice. Thus, if Dirks is distinguishable on the basis of its stepping in a vertical direction, Cole was nevertheless obvious from the prior art and invalid under 35 U.S.C. § 103. [558 F.Supp. at 948, 217 USPQ at 428.]
This was the extent of the district judge’s obviousness analysis that included a mention of Dirks.
The excerpts indicate that it is not clear whether the district judge relied on Dirks in his obviousness analysis.3 While the text speaks of combining Evans, Jones and Gordon, footnote 15 states that Cole was obvious in light of Dirks and Brown. The district judge seemed to have either ignored Dirks in the obviousness analysis or believed that an anticipatory reference such as Dirks need not or could not be included in such analysis. The factfindings fail to disclose to us the steps by which the district judge reached his obviousness conclusion. See Kelley, supra; Morow, supra. It is confusing as to whether he relied on or ignored Dirks in the factfindings regarding the “differences” between Cole and the prior art references. See Packer, supra. Failure to explicitly include Dirks in factfindings regarding the “differences” so as to provide an appellate court with a clear understanding of the basis of the district court’s obviousness determination is reversible error. See Golf City, supra; United Shoe, supra.
. The holdings of the U.S. Court of Claims and of the U.S. Court of Customs and Patent Appeals ("CCPA”) were adopted as precedent of this court. South Corp., 690 F.2d at 1370, 215 USPQ at 658.
It is interesting to note that both the Federal Circuit and the CCPA had considered the issue of strict identity between an invention and anticipatory prior art. This issue is related, if not the same, as the equivalency issue enunciated in Tate Engineering. See In re Smith, 714 F.2d 1127, 1137 n. 13, 218 USPQ 976, 985 n. 13 (Fed.Cir.1983); In re Foster, 343 F.2d 980, 52 CCPA 1808, 145 USPQ 166 (1965), cert. denied, 383 U.S. 966, 86 S.Ct. 1270, 16 L.Ed.2d 307 (1966). See generally 1 D. Dunner, J. Gambrell, M. Adelman & C. Lipsey, PATENT LAW PERSPECTIVES 2-30 (2d ed. 1984).
. The district judge stated:
In support of their obviousness argument, HLA rely not only on Dirks but also upon Jones, et at, Gordon, et al. and Evans, et at [Footnotes omitted.] [558 F.Supp. at 951, 217 USPQ at 430]
As explained in an earlier footnote, I conclude that Cole, if not anticipated by Dirks, is obvious from Dirks in light of Brown et al. and others. See n. 6, supra. [558 F.Supp. at 952, 217 USPQ at 431.]
. Contrary to majority’s belief that appellees alone contributed to the district court’s confusion, RCA also contributed to that confusion. In a footnote on page 39 of its Post-Trial Brief, RCA stated:
As noted earlier, the inoperativeness of the foreign Dirks patents removes them from possible consideration as anticipatory references, * * * and from consideration as to the obviousness of the Cole patent * * *.
In addition, RCA, on page 18 of the same Post-Trial Brief, acknowledged HLA’s arguments at trial regarding the obviousness of the Cole invention in light of Dirks.