Endress + Hauser, Inc. v. Hawk Measurement Systems Pty. Ltd. (892 F. Supp. 1107, 1995)

ENTRY REGARDING PATENT VALIDITY ISSUES

BARKER, Chief Judge.

In the first part of the bifurcated trial, this Court found that Defendants Hawk Measurement Systems Pty. Limited, Inc., and Hawk America, Inc. (“Defendants” or “Hawk”) literally infringed Plaintiffs Endress + Hau-ser, Inc.’s and Endress + Hauser GmbH’s (collectively “E + H” or “Plaintiffs”) patent. See Endress + Hauser, Inc. v. Hawk Measurement Systems Pty., 32 U.S.P.Q.2d 1768, 1994 WL 736442 (S.D.Ind. Aug. 29, 1994). On April 3-6, 1995, this Court conducted a bench trial on the remaining issues of patent validity and damages. Having considered the evidence, authorities, and briefing, the Court finds that claims 43, 44, and 46 are not invalid. The Court will address the issue of damages in a subsequent entry.

I.FINDINGS OF FACT ON VALIDITY

A. Introduction

1. The Court’s previous opinion dated August 29, 1994, and reported at 32 USPQ2d 1768 (S.D.Ind.1994), set forth the identities of the parties, the nature of the technology, and the facts and circumstances surrounding the infringement of the ’650 patent by Hawk.

2. The Court previously found that certain devices made and sold by Hawk literally infringe claims 43, 44, and 46 of the ’650 patent. For purposes of the following analysis of validity, claims 43, 44, and 46 are at issue.

3. Claims 43, 44, and 46 relate generally to a control system for use in monitoring the level of material in a storage tank. (DX1). The system addresses the problem of selecting the true echo return from multiple false echoes returning from the tank sidewalls. (DX1, col. 2, lines 24-33). Included in the claimed system is circuitry providing level indicating means which discriminates among the echo returns to select the true echo return from the multiple false returns. (DX1).

4. Hawk focuses on the prior art “Donar” publication (DX21) and two prior art patents, U.S. Patent No. 2,943,296 to Fryklund (DX-10) (“the Fryklund patent”) and U.S. Patent No. 3,921,122 to Christoff (DX25) (“the Christoff patent”). Hawk argues that each of claims 43, 44, and 46 is anticipated by the Donar reference. Hawk also argues that the claimed invention in each of claims 43, 44, and 46 would have been obvious in view of the Donar publication combined with the Fryklund patent. Hawk also contends that the claimed invention in each of claims 43, 44, and 46 would have been obvious in view of the Christoff patent combined with the Fryk-lund patent.

B. Prior Art

1. The Donar Publication (DX21)

5. The Donar publication (DX21) describes an experimental imaging system in which the objective is to process all of the returns to develop a “picture” of the entire environment being imaged. (Silva Testimony). The Donar publication (DX21) does not describe a level measurement system, in which the objective is to select a single return representing the distance between the transducer and the level of the material being measured, nor does the Donar publication contain any suggestion that the system it describes be combined with level measurement technology. (Silva Testimony).

6. Mr. Beazley, the designer of the infringing Hawk device, performed a worldwide literature search for prior art references that might be reasonably pertinent to the problem of designing a level measurement system for operation in a closed environment, and in doing so did not identify the Donar publication. (Beazley Testimony).

7. The Donar publication describes an experimental imaging system (see functional diagram, Fig. 1 of DX21 at p. 167) and three experiments designed to evaluate the system’s performance (see Figs. 4a and b; Figs. 5a and b; and Figs. 6-9, DX21).

8. The experiments illustrated in Figs. 5 and 6-9 of the Donar publication confirm that the object of the Donar system is to provide an image, rather than to provide a single number representative of distance as would be the case in a level measurement system. (Silva Testimony). In the Fig. 5 experiment, in which the ultrasonic pulse is used to measure the thickness of a 1.67 mm lueite plate in water, at least a portion of the ultrasonic pulse (referred to as the “thickness mode wave”, DX21, p. 172) must be propagated through the plate. Similarly, in Figs. 6-9, the system is used to measure the dimensions of a PVC tube having an outer diameter of about 2.5 mm (i.e., about one-tenth of an inch) in water. There is no evidence that this imaging operation bears any resemblance to a level measurement operation, in which the ultrasonic pulse would be reflected from the top surface of the material to be measured, and penetration through the material would be avoided.

9. Nowhere in the discussion of the Fig. 5 or Figs. 6-9 experiments is there any disclosure or suggestion of the geometry or dimensions of whatever container is used to hold the water. Hawk’s demonstrative diagram DX92, which hypothesizes a container of a specified geometry having sidewalls of a particular dimension, is without factual foundation because no such disclosure is actually found in the Donar reference. In addition, DX92 is inherently unbelievable because the container illustrated in that diagram would be less than half an inch wide.

10. Because Hawk’s illustration of the hypothetical tank sidewalls is without any foundation in the actual Donar publication, Hawk’s illustration of multiple false echoes reflecting from those sidewalls is equally lacking in any factual foundation. The Do-nar publication does not contain any disclosure of multiple false echoes reflecting from any imagined container sidewalls. (Silva Testimony). The inventor of the ’650 patent addressed the problem of discriminating among multiple false echoes in a closed environment to identify the true echo representing level. (DX1, col. 2, lines 24-33). Thus, the experiments described in Figs. 5 and 6-9 of the Donar publication are not even directed to the problem being addressed in the ’650 patent.

11. The description of the Fig. 4 experiment in the Donar publication does not mention the relative dimensions of whatever container may have been used to contain the water, or the dimensions of the aluminum plate. (DX21). Nor does it refer in the Fig. 4 experiment to multiple false echo reflections received from hypothetical sidewalls. (Silva and Beazley Testimonies).

12. The Fig. 4 experiment only illustrates the output pulse from the transducer itself by directing the output pulse through water at an aluminum plate, where the aluminum plate was effectively acting as an acoustic mirror. (Silva Testimony). The Fig. 4 experiment had two purposes, neither of which has anything to do with level measurement. First, the experiment “presented the opportunity of examining the waveform from the bismuth alloy-backed transducer” itself. (DX21, Fig. 4a, p. 171; Silva Testimony). Second, the experiment showed that the transducer pulse was “well-damped” (that is, the transducer flexed initially and oscillated only briefly thereafter). (DX 21, Fig. 4b, p. 171; Silva Testimony).

13. Hawk’s arguments that Figs. 4a and 4b disclose multiple false echo returns (and circuitry for dealing with such returns) lack a factual basis. There is no basis in the Donar reference for the conclusion that Fig. 4a illustrates multiple false echo returns from hypothetical tank sidewalls, and there is likewise no basis for the conclusion that Fig. 4b illustrates the automatic selection, by the Donar circuitry, of the true echo after the elimination of false echoes. (Silva Testimony). Instead, Figs. 4a and b represent nothing more than the transducer “taking a picture of itself’ using the aluminum plate as an acoustic mirror. Id.

14. Hawk also emphasizes that the system described in the Donar publication includes a computer. However, the Donar publication does not disclose or suggest that the computer should be programmed to select the maximum from among multiple false echo returns, because there is no mention of false echo returns in the Donar publication. (Silva Testimony). That the Donar publication refers to the printing of selected parts of a curve, including maxima, as one of its data evaluation options, makes no difference to this analysis. Even if this data evaluation option were chosen, an operator would be needed to review the group of maxima and select from among them the desired return. (Silva Testimony).

2. The Fryklund Patent (DX10)

15. Fryklund discloses an ultrasonic level measurement system that employs analog techniques that were in use in the 1950’s. (DX10).

16. Hawk has admitted that Fryklund, taken alone, lacks converting means, level indicating means, integrating means, and monitoring means. (DX104). Hawk thus has effectively admitted that Fryklund does not anticipate any of the claims and is relevant only to the extent that it might be combined with other prior art references as part of Hawk’s obviousness defense.

17. During prosecution of the patent application which matured into the ’650 patent, the patent applicant disclosed the Fryklund patent to the patent examiner, (PX B, Amendment Before First Action, pp. 4-5), and explained why Fryklund could not be properly combined with certain other prior art references as part of an obviousness rejection. (PXB, Amendment Before First Action, pp. 13-15).

3. The Christoff Patent (DX25)

18. The Christoff patent discloses a digital signal processing and display technique that is used in a target tracking sonar system. (DX25, col. 2, lines 3-7). The sonar system is specifically designed for use as a hazard avoidance aid in the operation of high speed watercraft. (DX25, col. 2, lines 15-18).

19. Although Hawk relies somewhat tentatively on the Christoff patent, there is no evidence that Christoff is any more material than any of the numerous sonar references that were considered by the examiner during prosecution. Generally, there is no evidence that the problem of tracking high speed watercraft bears any relationship to the problem of discriminating among multiple false echoes in a closed environment to identify the true echo representing level; and there is no suggestion in Christoff that the system being described could be combined with level measurement technology. (Silva Testimony). The ocean is not a closed environment and its acoustic characteristics are not comparable to those in a storage tank. (Silva Testimony).

20. The system disclosed in the Christoff system displays multiple dots (called “pips”) representing echo returns, but no automatic mechanism is provided to differentiate among the dots (i.e., to identify the time tag corresponding to any given return and to determine the maximum). (Silva Testimony). Instead, a human operator must differentiate among the dots by their brightness. (Beazley Testimony) (Silva Testimony). In the context of sonar systems at that time, it was thought desirable and necessary to use a highly trained human operator to interpret the dots. Such an operator had to be sophisticated enough to distinguish enemy vessels (which might not be represented by the strongest dot) from friendly vessels and to determine the rate of approach of such vessels, tasks which are still difficult today even with the benefit of recently-developed, highly sophisticated electronic pattern recognition techniques. (Silva Testimony). Thus, Chris-toff teaches away from the automatic selection of a true echo from multiple false echoes.

4.Other Prior Art References

21. Throughout the trial of the validity issue, Hawk referred to a summary chart, DX104, which purported to compare claims 43, 44, and 46 to numerous prior art references. The testimony offered by Hawk as to many of the references listed on DX104 (particularly DX80, DX7, DX26, DX77, DX23, DX22, and DX24) did little more than recite the contents of DX104 itself. Such testimony falls far short of the clear and convincing standard. The summary chart listed only selected elements of the patent claims at issue. No effort was made to explain by clear and convincing evidence that each of the elements of the claims at issue was actually disclosed in any one of the listed prior art references. In addition, Hawk changed numerous entries on the chart from “No” (indicating an admission that the given prior art reference did not disclose a particular claim element) to “X,” (retracting that admission) during the trial.

22. Although Hawk discussed a multiplicity of prior art references, it relies in its post-trial briefs on three of those references. Accordingly, in its analysis of the validity of the claims at issue, the Court will give less consideration and weight to the prior art references listed on DX104, which have not been discussed in the briefing.

C. Anticipation

Hawk contends that the Donar publication anticipates each of claims 43, 44, and 46. The Court rejects Hawk’s anticipation defense as to each of the claims.

1. Claim 43

23. Claim 43 relates to “a control system for use in monitoring the level of material in a storage tank.” (DX1).

24. Claim 43 also calls for “level indicating means.” This Court has already determined that the “function” specified by the level indicating means limitation of claim 43 “involves comparing a series of sample values, each representing the intensity of an echo pulse, to identify the maximum sample value.” Slip Op. at 10, 32 USPQ2d at 1771 (Infringement Fact Finding no. 41). This Court further noted that the function “involves identifying the ‘time tag’ corresponding to the maximum sample value in order to determine the total transit time of the pulse from the transducer to the material level and back, because the total transit time is used to provide an indication of the distance between the transducer and the material level.” Id. (Infringement Fact Finding No. 43).

25. This Court has already determined that the means disclosed in the ’650 specification for performing the level indicating function “may be referred to as a ‘digital integrator’ (comprising adder 124, MOS register 126, and AND gates 128) followed by a ‘digital peak detector’ (comprising comparator 130, maximum value register 132, and address register 134), or may be referred to as a series of components which perform digital data storage, conditioning, and comparison ...” Slip Op. at 13, 32 USPQ2d at 1772 (Infringement Fact Finding No. 51).

26. The Donar publication (DX21) does not disclose a control system for use in monitoring the level of material in a storage tank. Quite to the contrary, it discloses a computer-controlled experimental imaging system designed for application to biological specimens. (Silva Testimony).

27. The Donar publication does not describe performance of the level indicating function set forth in claim 43 and as interpreted above, because there is no disclosure that the Donar system is used to select a maximum sample value and corresponding time tag from among a series of false echo returns. (Silva Testimony).

28. The Donar publication does not include the same or equivalent circuitry as that disclosed in the ’650 patent for performing the level indicating function, because while the Donar system includes a computer, there is no disclosure of programming the computer to select a maximum sample value and its associated time tag from among a series of false echo returns. (Silva Testimony).

29. Because the Donar publication does not disclose a control system for use in monitoring the level of material in a storage tank, and because the Donar publication does not disclose level indicating means, there is no clear and convincing evidence that the Donar publication anticipates claim 43. The Court rejects Hawk’s challenge to the novelty of claim 43 based upon the Donar publication.

30. Because there is no clear and convincing evidence that any of the other prior art references that have been brought to the Court’s attention in this case disclose level indicating means, and because all but one of them (Fryklund) fail to disclose a control system for monitoring the level of material in a storage tank, any challenge to the novelty of claim 43 based upon those prior art references is rejected.

2. Claim 44

31. Claim 44 recites that the level indicating means includes integrating means and monitoring means. (DX1).

32. Having found that neither the Donar publication nor any of the other prior art references at issue disclose level indicating means at all, the Court finds for the same reasons that none of those references discloses the level indicating means as more narrowly defined in claim 44.

33. Thus, there is no clear and convincing evidence that the Donar publication or any of the prior art at issue anticipates claim 44. Hawk’s novelty challenge to claim 44 fails.

3. Claim 46

34. Claim 46 specifies the position of the transducer (“mounted to the top of said storage tank”) as well as the orientation of the transducer (“directed to transmit pulses downwardly toward and to receive pulses reflected upwardly from said material surface”). Claim 46 also specifies the medium through which the ultrasonic pulse is transmitted (“an air space between said tank top and said material surface”).

35. Nowhere in the Donar publication is there any disclosure of the transmission of an ultrasonic pulse through “an air space between said tank top and said material surface” to measure distance; the only disclosure is of the transmission of ultrasonic pulses through water (and through the solid test objects). (Silva Testimony). Nowhere in any of the other prior art references at issue (except Fryklund, which is not alleged to anticipate any of the claims) is there any disclosure of the use of air as the coupling medium. (Silva Testimony).

36. The Donar publication does not disclose a storage tank, much less describe where on the storage tank the transducer is mounted. Because the Donar publication does not describe the orientation of the transducer relative to the material being measured, there is no way to tell whether the ultrasonic pulse is directed “downwardly”. Defendants’ demonstrative exhibits DX92 and DX133, which purport to show a transducer mounted at the top of a storage tank and oriented to transmit its pulse downwardly toward the material surface, are not based upon descriptions from the Donar publication and thus are without factual foundation.

37. Even were we to conclude that the Donar publication discloses every limitation of claim 43, the Court would still conclude that the Donar publication does not disclose the additional limitations of claim 46 requiring transmission downwardly, through an air space.

38. Because there is no clear and convincing evidence that the Donar publication or any of the other prior art references at issue disclose each and every limitation of claim 46, the Court rejects Hawk’s novelty challenge to claim 46.

D. Fact Findings: Obviousness

Hawk contends that the Donar publication, combined with the Fryklund patent, would have rendered the subject matter of claims 43, 44, and 46 obvious. Hawk also contends that the Christoff patent, combined with the Fryklund patent, would have rendered the subject matter of claims 43, 44, and 46 obvious. The Court rejects Hawk’s obviousness defense as to each of the claims.

1. Graham Factors

a. Scope and Content of the Prior Art

39. The area of endeavor to which the claimed invention is directed is level measurement in a confined storage tank. Prior art references directed to sonar systems in submarines, radar detection, and imaging systems (e.g. for biological specimens) are outside the relevant field of endeavor.

40. Prior art references directed to sonar systems in submarines, radar detection, and imaging systems (e.g. for biological specimens) are not reasonably pertinent to the problem sought to be solved by the inventor, namely the problem of discriminating among multiple echo returns in a closed storage tank. (Silva Testimony).

41. Accordingly, none of the prior art references relied upon by Hawk except the Fryklund patent, DX10, is analogous art that can properly support an obviousness defense. Although the Court would be entitled to ignore these references in reaching its ultimate legal conclusion of nonobviousness, the Court will evaluate the references as if they were analogous art, for purposes of completeness.

b. Differences Between the Claimed Invention and the Prior Art

42. Hawk argues that if the Donar publication is combined with the Fryklund patent, the differences between that combination and each of claims 43, 44, and 46 are such as to establish obviousness. Hawk maintains that the Donar publication discloses all of the digital signal processing techniques, while Fryklund teaches the use of a material level control system in which the signal propagates through air.

43. Hawk’s argument recalls the very argument presented to the patent examiner during prosecution. The patent applicant pointed out that U.S. Patent No. 3,422,436 to Cragon et al (DX7) disclosed digital signal processing techniques in a radar system (PX B, Amendment before First Action, p. 13), but that it lacked any suggestion that such digital processing be used in the confined environment encountered by a material level control system. (PX B, Amendment before First Action, p. 14). Under such circumstances, the Court finds that only hindsight guided by the patent applicant’s disclosure would have motivated one of ordinary skill in the art to combine Cragon et al. with a material level control patent such as Fryk-lund. (PX B, Amendment before First Action, p. 15).

44. Likewise here, the Donar publication does not suggest that the Donar system is designed to deal with multiple false echoes. The differences between the Donar publication and the subject matter of claims 43, 44, and 46 are substantial. Indeed, the differences between the Donar publication and the claimed subject matter as a whole are so substantial that E + H’s technical expert, Dr. Silva, testified that he was “amazed” that the Donar publication had been brought up, and that the Donar publication was less material to patentability than the Cragon patent that the patent examiner considered during the prosecution. (Silva Testimony). Only through the exercise of hindsight reconstruction can it be claipréd that one of ordinary skill in the art,w6uld have been motivated to combine the