The opinion of the court was delivered by: RADER
RADER, Circuit Judge (Sitting by Designation)
In this patent case, Loral Fairchild Corporation sued numerous Japanese electronics companies for infringement of United States Patents 3,931,674 (the 674 patent) and 3,896,485 (the '485 patent). In August 1995, the court severed and stayed all of the non-manufacturing consumer defendants, leaving six core groups of manufacturing defendants -- Sony, Sanyo, Toshiba, Hitachi, NEC, and OKI. On October 11, 1995, the court ordered separate trials for each of the six groups of manufacturing defendants and scheduled trial dates for each.
Over the course of five weeks in January and February, 1996, Loral Fairchild Corporation (Loral) and Sony Electronics, Inc. and Sony Corporation (Sony) tried the issues of ownership, validity, and infringement of the two patents to a jury. On February 14, 1996, the jury returned a verdict finding that Loral owns the patents, that Sony did not prove invalidity of the asserted claims, and that Loral had proven infringement. The jury also found that Sony induced infringement of the '674 patent but did not induce infringement of the '485 patent. After the verdict, Sony moved for judgment as a matter of law (JMOL) or for a new trial.
Loral and Sony then tried the remaining liability issues to the court on April 15 and 16, 1996. This Opinion is the court's decision on Sony's post-trial motion as well as the court's findings of fact and conclusions of law or prosecution history estoppel, equitable estoppel, and laches.
Because no reasonable jury could find that Sony infringed the two patents, this court grants Sony's motion for judgment as a matter of law. In addition, this court finds prosecution history estoppel prevents Loral from asserting the doctrine of equivalents to cover Sony's accused products. However, this court finds that neither equitable estoppel nor laches bar recovery in this suit.
This court has issued several opinions in this case which discuss the technology, the patents, and the claims. See Loral Fairchild Corp. v. Victor Co. of Japan, 911 F. Supp. 76 (E.D.N.Y. 1996) (imposing discovery sanction); Loral Fairchild Corp. v. Victor Co. of Japan, 906 F. Supp. 813 (E.D.N.Y. 1995) (granting defendants' motion for summary judgment on marking); Loral Fairchild Corp. v. Victor Co. of Japan, 906 F. Supp. 798 (E.D.N.Y. 1995) (construing disputed claims of the patents). This opinion builds on the foundation of those earlier decisions. This opinion assumes familiarity with those preceding decisions.
Claim 1 of the '485 patent reads:
Structure which comprises:
a. a light sensing element comprising a first region of semiconductor material overlaid by a first electrode separated from said semiconductor material by insulation, said light sensing element being capable of containing a charge packet;
b. an adjacent region of said semiconductor material disposed for receiving said charge packet from said light sensing element;
d. charge sink means having a contract for applying a bias thereto buried within said semiconductor material and disposed for receiving excess charge accumulated in said light sensing element, said charge sink means extending laterally from said contact toward said light sensing element while beneath the surface of said semiconductor material.
This court interpreted the disputed portions of this claim language. Loral, 906 F. Supp. at 807-12. Summarizing this court's detailed claim construction, "charge sink means" describes a means-plus-function limitation. In accord with the specification, this court determined that the charge sink means is a region of semiconductor material doped opposite from its surrounding semiconductor material. The charge sink means does not include its associated depletion region. Thus, the charge sink means is a separate and distinct structure within the semiconductor substrate.
Claim 1 also provides a description of the location of this structure. The language identifies the "charge sink means" structure as "buried within said semi-conductor material." Further the claim places this structure "beneath the surface of said semi-conductor material." The "buried within" and "beneath the surface" language means the charge Sink structure is surrounded by and submerged within the semiconductor material.
This court construed "contact" to mean one or more electrical paths for charge to flow to and from the charge sink means. Lastly, this court interpreted the phrase "extending laterally from said contact toward the light sensing element" as conveying more information about the location of the charge sink structure. This directional language requires the charge sink structure to stretch from the contact toward the light sensing element. Thus, this buried structure extends parallel to the semiconductor's top surface and, perpendicular from a contact toward the light sensing element. Figure 1 of the '485 patent provides an excellent depiction of the location of the charge sink structure.
During the course of the claim construction trial, the court heard extensive testimony about the reasons for a "buried" charge sink means. Semiconductor devices sense light with a structure that converts light waves into electrical charges. The light sensing element in the device, however, has a certain charge capacity. Intense light can cause the element to exceed its capacity causing excess charge to spill out of the light sensing structure and flow into adjacent light sensing elements. The result of this overflow is blooming -- a spreading distortion of light on the detected image. To prevent blooming, the chip includes a structure to capture and dissipate excess charge from the light sensing elements. These charge capturing devices prevent the excess charge from spilling over into adjacent light sensing elements. Initially, chip designers placed these charge drains next to the light sensing elements on the surface of the chips. See C.H. Sequin, Blooming Suppression in Charge Coupled Area Imaging Devices, The Bell System Technical Journal, October 1972; United States Patent 3,866,067. However, surface drains occupied valuable light sensing space on the surface of the chip. To achieve higher resolution in light detection, designers sought to remove charge drains from the chip surface leaving more room for light sensors. Early's '485 patent represents a step toward solving this problem by placing a drain structure below the surface of the chip to capture the excess charge below the light sensing element. [See Transcript of September 19, 1995, Hearing, at 32-33]. Consequently, the claims of the '485 patent cover a structure entirely beneath the surface of the chip.
At trial the parties disputed whether Sony's accused CCD devices satisfied elements (a) and (d) of claim 1 of the '485 patent under the doctrine of equivalents. The parties also disputed whether Sony's devices infringed the method claims 7 and 8 in the '485 patent. The jury found that Loral had proven that Sony's devices infringe all of the asserted claims.
Loral asserts infringement of claim 1 of the '674 patent, which describes a process for making a self-aligned, gapless charge-coupled device (CCD). Claim 1 reads:
1. A process for fabricating a charge coupled device structure in a semiconductor substrate, comprising the steps of
 selectively applying at least one layer of insulation material to said semiconductor substrate;
 selectively forming a plurality of spaced-apart first gate electrodes on the. uppermost surface of said at least one layer of insulation material;
 forming a first insulation layer over said plurality of first gate electrodes;
 forming implanted barrier regions in said semiconductor substrate in the intervals between said plurality of spaced-apart first gate electrodes, the edges of said implanted barrier regions being aligned with the vertical edges of the insulation layer on the respective first gate electrodes;
 selectively forming a plurality of second gate electrodes on said uppermost surface of said at least one insulating layer between said plurality of spaced-apart first gate electrodes, each of said second gate electrodes substantially occupying the space between adjacent first gate electrode; and
 connecting each of said second gate electrodes to and individual adjacent first gate electrode to form a composite electrode for a charge coupled element.
United States Patent 3,931,674 (bracketed numbers added to facilitate references).
As with the '485 patent, this court construed the disputed portions of claim 1. Loral, 906 F. Supp. at 803-07. In particular, this court constructed the claim to require formation of the insulation layer over the first gate electrodes before implantation of the barrier regions. In other words, the claim requires a process sequence with step three preceding step four. Id. at 806.
This court also invited the parties to renew motions for summary judgment on the '674 patent. On December 14, 1995, this court ruled that elements 1, 2, and 6 of claim 1 of the '674 patent read on Sony's processes.
On that same day, this court granted Sony's motion for summary judgment of no literal infringement of claim 1 because its processes all use a naked gate as a mask. In other words, Sony's process performs claimed step four before step three. However, this court denied all the motions for summary judgment on infringement under the doctrine of equivalents.
The case proceeded to trial on Loral's claim that Sony's processes infringe claim 1 of the '674 patent under the doctrine of equivalents. At trial, Loral called several witnesses to testify about the insubstantiality of the changes between the claimed invention and Sony's processes.
Sony also alleges its processes do not satisfy the fifth limitation of the claim, which requires formation of the second gate electrodes between the first gate electrodes on the upper surface of the same continuous insulation layer with the first gate electrodes. At trial, Sony offered transmission electron micrographs (TEMs) to demonstrate that its processes do not form the second gate electrodes exactly on the same surface as the first gate electrodes. [STX 12, 13, 14, and 15]. In its case-in-chief, Loral relied on scanning electron micrographs (SEMs) to show substantial compliance with that claim limitation. According to Sony's expert, Mr. Denboer, however, SEMs do not sufficiently magnify the structure to reveal layer differentiation. [TR 2808-09].
In addition, Sony argues that prior art to the '674 patent describe its processes and thus limits application of the doctrine of equivalents. In particular, Sony argues work at Hughes Aircraft Company by Drs. Erb and Su, which culminated in a December 3, 1973, article, describes Sony's manufacturing processes. As such, Sony merely practices known prior art processes in the public domain to manufacture its accused CCDs. Sony called Drs. Erb and Su to testify about their work at Hughes during the relevant time period.
Prosecution History Estoppel
Beyond its arguments that the prior art limits the scope of the doctrine of equivalents and that its processes substantially differ from the claimed process, Sony argues the prosecution history prevents Loral from asserting infringement against Sony's processes and CCDs. The parties filed pretrial motions on the issue of prosecution history estoppel. This court denied Sony's motion and submitted the issue to the jury over the objection of both Loral and Sony. This court, however, advised the parties that it would treat the jury's verdict on this issue as advisory only. Indeed this court devoted significant time to resolution of the prosecution history estoppel issue in a separate hearing and argument several months after the jury trial.
Loral argues claim 1 of the '674 patent describes a process which implants barrier regions either before or after insulation of the first gate electrodes. Loral contends that the claim can cover a process which perform; step four before step three. Sony contends Loral surrendered during prosecution any deviation from the process sequence.
The '485 patent also presents prosecution history estoppel questions. Sony argues that the prosecution process confined the '485 patent to a charge sink means buried within the substrate, not in contact with the surface, and extending laterally from the contact toward the light sensing element. Loral claims the prosecution history does not preclude Loral from asserting a range of equivalents that would include Sony's substrate drain.
In this case, the trial record thoroughly examined the prosecution history of both the '674 and '485 patents. Beyond examination of the file wrapper, this court and the jury heard extensive inventor and expert testimony about the administrative, acquisition of these patents. In its advisory capacity, the jury found that: (1) Sony did not prove by a preponderance of the evidence that Dr. Amelio surrendered or abandoned a 4-before-3 process sequence during acquisition of the '674 patent; and (2) Sony did not prove by a preponderance of the evidence that Dr. Early abandoned or surrendered a charge sink that covers Sony's substrate drain during the '485 prosecution history.
Finally, Sony contends the equitable defenses of laches and estoppel bar recovery by Loral in this case. Sony had claimed unenforceability for inequitable conduct but waived that defense before the trial on the equitable issues. The court heard testimony and received exhibits during the course of a two-day trial in April, 1996.
This Opinion will first address Sony's renewed motion for judgment as a matter of law. This analysis will include conclusions on prosecution history estoppel. The Opinion will then discuss this court's findings and conclusions on the equitable issues presented in the bench trial.
Sony filed a renewed motion for judgment as a matter of law under Fed. R. Civ. P. 50(b). Sony challenges the jury's verdict on the issues of ownership, infringement, and inducement to infringe. Curiously, Sony does not challenge the jury's verdict on validity.
A Rule 50 motion tests the sufficiency of evidence in support of a jury verdict. Milbank, Tweed, Hadley & McCloy v. Boon, 13 F.3d 537, 542 (2d Cir. 1994), accord Litton Sys., Inc. v. Honeywell, Inc., 87 F.3d 1559, 1996 WL 379259, at *4 (Fed. Cir. 1996). In evaluating a Rule 50 motion, this court reviews the record to ascertain whether a reasonable jury could have reached the verdict in the case. Milbank, 13 F.3d at 542. Where substantial evidence supports its findings, this court must uphold the jury's verdict. Goodwall Constr. Co. v. Beers Constr. Co., 991 F.2d 751, 754 (Fed. Cir. 1993). Moreover, this court must view the evidence in the light most favorable to Loral, drawing reasonable inferences favorable to Loral, without determining credibility of witnesses, and without substituting its choice for that of the jury. Wang Labs, Inc. v. Toshiba Corp., 993 F.2d 858, 863 (Fed. Cir. 1993). In sum, this court must deny a renewed JMOL motion unless the movant shows that no reasonable jury could have reached its result. Goodwall, 991 F.2d 751. In determining that no reasonable jury could have reached its result, the evidence must be "so overwhelming that reasonable and fair minded persons could only have reached the opposite result." Sorlucco v. New York City Police Dep't, 971 F.2d 864, 871 (2d. Cir. 1992) (quoting Stubbs v. Dudley, 849 F.2d 83, 85 (2d. Cir. 1988), cert. denied, 489 U.S. 1034, 103 L. Ed. 2d 230, 109 S. Ct. 1095 (1989)).
With this lofty standard in mind, this court discerns substantial evidence in support of the jury's verdict on ownership. Loral called Steven Wahl, the general counsel involved in the asset transfers at issue, to testify about the various transfers of interests. Loral also offered the various agreements purporting to transfer the patents from company to company.
Based on the testimony and the document, a reasonable jury could have concluded that Loral Fairchild owned the patents in suit. Both inventors assigned the patents to Fairchild Camera & Instrument Corporation (FCIC). FCIC was renamed Fairchild Semiconductor Corporation (FSC). [TR 954-55, PTX 1037, PTX 41]. By written agreement and subsequent written assignment, FSC transferred title to the patents to Fairchild Weston Systems, Inc. (FWSI). Schedule A to those documents listed the patents. Loral Fairchild acquired the assets of FWSI. [TR 955-60, 1072-75, PTX 1037, PTX 41, PTX 70]. In 1989, FWSI separately assigned the patents to Loral Fairchild. [TR 960-61, PTX 1037, PTX 41].
Because neither party challenges the jury instructions, this court now turns to the core issue in this case -- infringement of the asserted claims of the two patents under the doctrine of equivalents.
Sony's Motion for JMOL on the '485 Patent
However, no reasonable jury could find Sony's accused devices infringe any asserted claim of the '485 patent. Infringement of a claim requires, "without exception, that an accused device contain each limitation or its equivalent." Athletic Alternatives, Inc. v. Prince Mfg., Inc., 73 F.3d 1573, 1582 (Fed. Cir. 1996). The doctrine of equivalents grants no license to ignore claim limitations. Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 397 (Fed. Cir. 1994); accord Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1996 WL 309648, at *4 (Fed. Cir. 1996); see Texas Instruments Inc. v. United States Int'l Trade Comm'n, 988 F.2d 1165, 1171 (Fed. Cir. 1993); see also Unique Concepts, Inc. v. Brown, 939 F.2d 1558, 1563 (Fed Cir. 1991) ("Our interpretation gives full effect to the recitation of two distinct elements in the claimed structured linear border pieces and right angle corner border pieces."). Sony's devices do not contain a charge sink means as defined by the '485 claims.
Claim 1 of the '485 patent defines the charge sink means as a distinct structure of semiconductor material doped opposite from its surrounding semiconductor material. The claim also locates that structure within the semiconductor material. According to the claim, the charge sink means must extend parallel to the top surface of the semiconductor and perpendicular to a contact toward a light sensing element. Sony's accused devices contain no such structure as a matter of law. See Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 935 (Fed. Cir. 1987) (en banc), cert. denied, 485 U.S. 961, 99 L. Ed. 2d 426, 108 S. Ct. 1226 (1988); Dolly, 16 F.3d at 398.
In a Sony device, the entire substrate functions as a charge sink -- a so-called substrate drain. Because Sony's charge sink structure is the entire substrate, it has no structure distinct from the surrounding substrate. Without this structure, nothing is doped opposite from the surrounding semiconductor material. Nothing is "buried within" the semiconductor material. Nothing extends from the contact toward the light sensing element beneath the surface of the semiconductor material. Moreover, Sony's substrate is in contact with a surface of the semiconductor (indeed it forms at least one surface) and thus cannot be "buried within" the semiconductor material. In sum, nothing meets element d of claim 1 of the '485 patent. Loral's effort to write this limitation out of the claim by way of the doctrine of equivalents violates the all elements rule.
Figure 1 of the '485 patent -- relied upon extensively by both parties to describe element d of claim 1 -- depicts well the charge sink defined by the claims. This figure shows an elliptical region (14) with an N doping, opposite from the surrounding P material (11, 12). This elliptical structure extends from the contact (16) toward the light sensing element (28a). The Sony accused devices have no such structure. Instead the substrate beneath the light sensor, represented by the P region (11,12) in Figure 1 of the '485 patent, functions to remove excess charge from the light sensing region and prevent blooming. While looking to Figure 1 to enlighten the meaning of the claim terms, this court recognizes that this drawing represents only one embodiment of the claims.
Attempting to identify a charge sink means within the Sony device, Loral arbitrarily draws an ellipse in a region of semiconductor material under the Sony light sensing element. This ellipse is not a distinct structure in a Sony device at all, but merely ink marks on a graphic representation of the Sony device. In the actual Sony devices, no distinct structure separate from the surrounding semiconductor material exists at the location Loral highlights. Thus, the Sony device lacks a vital limitation in claim 1 of the '485 patent. Because Sony does not make, use, or sell the structure in claim 1, it also cannot infringe claims 7 and 8. These claims describe only methods of operating the structure in claim 1.
When first filed, element (d) of the application claim read:
charge sink means buried within said semiconductor material and disposed in proximity to said light sensing element for receiving excess charge accumulated in said light sensing element.
[STX 504 at E18]. The examiner objected to this language because it did not recite the location of the charge sink region other than within the semiconductor material and close to the light sensor. This description read on the prior art which included semiconductors with charge sinks located on the top surface of the device. [STX 504 at E24].
In response to the rejection, Loral amended element d to read:
charge sink means buried within said semiconductor material and disposed for receiving excess charge accumulated in said light sensing element, said charge sink means being located beneath and not in ...