Mediatube Corp. v. Bell Canada

Mediatube Corp. v. Bell Canada
Court (s) Database
Federal Court Decisions
Date
2017-01-04
Neutral citation
2017 FC 6
File numbers
T-705-13
Decision Content
Date: 20170104
Docket: T-705-13
Citation: 2017 FC 6
Montréal, Quebec, January 4, 2017
PRESENT: The Honourable Mr. Justice Locke
BETWEEN:
MEDIATUBE CORP. AND NORTHVU INC.
Plaintiffs/
Defendants by Counterclaim
and
BELL CANADA
Defendant
Plaintiff by Counterclaim
PUBLIC JUDGMENT AND REASONS
(Confidential Judgment and Reasons dated January 4, 2017)
TABLE OF CONTENTS:
I. Overview.. 3
II. The 477 Patent and its Background. 7
III. Issues in Dispute. 12
IV. Witnesses. 13
V. Claim Construction. 14
A. Applicable Law.. 14
B. Person Skilled in the Art 19
C. Analysis. 21
(1) “audio/video signals”. 22
(2) “conductors”. 26
(3) “server”. 29
(4) “controlling an output channel selection of the input signal”. 30
(5) “for each communications interface, a switching device”. 33
(6) Other Claims in Issue. 35
D. Conclusions on Claim Construction. 37
VI. Invalidity Issues. 38
A. Anticipation. 38
(1) Applicable Law.. 38
(2) Analysis. 40
(3) Conclusion on Anticipation. 44
B. Obviousness. 44
(1) Applicable Law.. 44
(2) Person Skilled in the Art 46
(3) Common General Knowledge. 47
(4) State of the Art 49
(5) Inventive Concept 57
(6) Differences between the Prior Art and the Inventive Concept and Whether those Differences Constitute Obvious Steps. 59
(7) Conclusion on Obviousness. 61
C. Overbreadth/Insufficiency. 62
D. Inutility. 62
(1) Applicable Law.. 62
(2) Analysis. 63
(3) Conclusion on Inutility. 67
E. Conclusion on Invalidity. 67
VII. Infringement Issues. 67
A. Applicable Law.. 68
B. Bell Canada’s System, as Described at Trial 69
C. Bell Canada’s System, as Described before the Corrected Information. 73
D. Bell Aliant’s System.. 78
E. Stand-by Utility. 79
F. Conclusion on Infringement 81
VIII. Costs. 81
A. The Corrected Information. 82
B. Bell’s “Patent Trolls” Allegation. 84
C. Bell’s Citation of 753 Prior Art References. 85
D. Infringement Allegations in respect of Bell Aliant 87
E. Infringement Allegations in respect of Bell Canada. 89
F. Plaintiffs’ Punitive Damages Claim.. 90
G. Conclusion on Costs. 93
IX. Conclusion. 94
JUDGMENT.. 95
APPENDIX.. 96
I. Overview [1] This case has morphed somewhat since it was commenced. Some issues have been removed and others have been added. For that reason, it is helpful to begin with a brief history of the litigation.
[2] This case began as a patent infringement action in which the patent owner (NorthVu Inc.) and a licensee (MediaTube Corp.) alleged that Bell Canada and Bell Aliant Regional Communications (collectively, Bell, and now a single entity) infringe Canadian Patent No. 2,339,477 (the 477 Patent) with their well-known Internet Protocol Television (IPTV) services called Fibe TV (offered by Bell Canada in the provinces of Ontario and Quebec) and FibreOp TV (offered by Bell Aliant in the provinces of Nova Scotia, New Brunswick, and Newfoundland and Labrador).
[3] The plaintiffs also alleged that Bell (i) had knowledge of the application that led to the 477 Patent back in 1999, (ii) sought out the plaintiffs and their predecessors in order to discuss the patented invention, (iii) worked with them (purportedly to commercialize the patented invention) after entering into a written confidentiality agreement, and (iv) eventually launched its own competing Fibe TV service without the plaintiffs’ involvement or prior knowledge. The plaintiffs alleged that Bell thus brazenly infringed the 477 Patent and severely damaged the plaintiffs’ business. As a result of these activities, the plaintiffs sought punitive damages.
[4] Bell denied infringement and asserted that the claims of the 477 Patent are invalid. Bell also characterized the plaintiffs as patent trolls. Among the grounds of invalidity were allegations that the claims were anticipated and/or obvious in view of a number of prior art references – many prior art references. Bell eventually identified 753 of them. With regard to the allegations in support of the punitive damages claim, Bell denied any impropriety, characterized the plaintiffs’ allegations as intentionally false, and indicated that it would seek costs against the plaintiffs on the basis of trebling their actual legal fees incurred.
[5] The stage was thus set for a high-stakes fight. However, as a patent infringement action, this case has become something of a damp squib. As the litigation advanced to and through trial, a number of important issues were taken off the table.
[6] In December 2015 the plaintiffs narrowed their infringement allegations concerning Bell Aliant’s FibreOp TV system by dropping their claim in respect of all fibre-to-the-home, or FTTH, subscribers (which, according to Bell, constitutes 96% of FibreOp TV subscribers), while maintaining their infringement claim against fibre-to-the-node, or FTTN, subscribers (which make up the remaining 4% of FibreOp TV subscribers). Information concerning these different types of subscribers is discussed in greater detail later in these reasons. In addition, upon the service of its experts’ reports in February 2016, Bell effectively reduced the number of prior art references that were being asserted to a small subset of the 753 listed in its pleading. Finally, during the summer before the commencement of trial on September 12, 2016, the plaintiffs limited the asserted claims of the 477 Patent to only claims 1, 2, 4 and 18. Narrowing the issues in the foregoing ways is not unusual. In fact, it is to be encouraged in order to assist the Court and the parties to focus on the real issues in dispute.
[7] However, there were far more unusual developments that have had the effect of changing the main thrust of this matter from one of patent infringement to one of allocation of costs. The context for some of these unusual developments was a series of changes to discovery answers. These changes were made by Bell beginning on January 31, 2016, and were provided in numerous installments in the months and weeks leading up to trial. The changes, which even included some additional information provided during trial, concerned details of Bell’s Fibe TV and FibreOp TV systems, and are referred to herein as the Corrected Information.
[8] The plaintiffs argue that they had a good, arguable case for establishing patent infringement prior to receiving the Corrected Information, that the Corrected Information should have been provided earlier and that, even after receiving it, the plaintiffs had reasonable doubts as to its accuracy. They also submit that, if they had known earlier what they know now about Bell’s systems, they would not have pursued this matter to trial. For these reasons, the plaintiffs ask that they be awarded costs regardless of my conclusions on patent infringement and validity.
[9] Another important development occurred at the beginning of the 14th day of the trial. The plaintiffs made two major admissions. Firstly, the plaintiffs acknowledged that the evidence established that Bell Aliant had never infringed the 477 Patent. Secondly, the plaintiffs withdrew their claim for punitive damages. These admissions came after the close of the plaintiffs’ case in chief, and after a number of witnesses for Bell had testified in relation to the Corrected Information, but before any evidence from Bell relating to the plaintiffs’ punitive damages claim.
[10] A final major development took place during the plaintiffs’ oral submissions on closing argument. There, the plaintiffs acknowledged for the first time that one aspect of Bell Canada’s Fibe TV service called unicasting XXXXX XXXXX XXXXX XXXXX XXXXX XXXXX XX does not infringe the 477 Patent. The plaintiffs also acknowledged that the other aspect of Bell Canada’s Fibe TV service called multicasting (which operates all the time) does not infringe except for its stand-by utility (that is, it could allegedly be made to infringe by modification of Bell’s system).
[11] In light of the foregoing, the only infringement issue that remains in dispute (the vestige infringement issue) concerns Bell Canada’s Fibe TV service, and the multicasting aspect of that service. The plaintiffs maintain that claims 1, 2, 4 and 18 of the 477 Patent are infringed, but only by virtue of the fact that the system could be modified to incorporate all of the essential elements of these claims.
[12] Because of these many late admissions by the plaintiffs, Bell argues that it should have its costs related to certain aspects of the action awarded at an elevated level, regardless of the outcome of the case. For their part, the plaintiffs seek elevated costs, regardless of the outcome of the case, because of certain allegations made by Bell. The parties’ respective submissions on costs are discussed later in these reasons.
[13] For the reasons set out below, I have concluded that the 477 Patent is valid but not infringed. I have also found that Bell should have its costs of this action, and that the amount of those costs should be elevated, for the reasons provided below, by 50% for most issues and on a solicitor-and-client basis in relation to the punitive damages claim.
II. The 477 Patent and its Background [14] The 477 Patent is entitled “Audio/Video Signal Redistribution System”. It issued on November 20, 2007, based on an application that was filed on July 30, 1999. That application claimed priority from an application that was filed in the United States on August 3, 1998, which the parties agree is the claim date of the 477 Patent as defined in s. 28.1 of the Patent Act, RSC 1985, c P-4. The application for the 477 Patent was published on February 17, 2000. The 477 Patent is set to expire on July 30, 2019.
[15] The named inventor of the 477 Patent is Ross Jeffery. He testified at trial with regard to his background and the development of the invention. This testimony is discussed in detail in relation to the issues of invalidity for overbreadth and for inutility. Mr. Jeffery also acted as the corporate representative of the plaintiff NorthVu Inc. during examinations for discovery.
[16] As stated in the Field of the Invention section, the 477 Patent “relates to an interactive audio/video telecommunications system which integrates and redistributes audio/video signals received in multiple formats to multiple users over existing telephone wires.”
[17] The Background of the Invention section discusses the demand in modern society for audio/video telecommunications services from different sources and in different formats. Television and internet are mentioned as examples of such services. The challenge described in the 477 Patent is to integrate the different types of services to “allow a user to instantaneously access any channel provided by any telecommunications or broadcast service using a single system … over a single network of wires.”
[18] The Summary of the Invention section describes:
a single system which redistributes audio/video signals received in multiple formats to multiple users. The invention allows each user to remotely select and control the audio/video signal source desired to be viewed or accessed and provides access [to] any available broadcast and telecommunications system through a single receiving unit.
[19] This section also states that the invention can be implemented over existing telephone wires, thus reducing the cost of implementation, and without interfering with the normal use of the telephone network.
[20] The 477 Patent describes a redistributing device for receiving a plurality of audio/video input signals in different formats and redistributing user-selected signals to multiple users. The redistributor is “installed at a multi-user site, which may for example be an apartment or condominium, commercial high rise, hospital, school, a local loop in a neighbourhood telephone system, etc.” At each user location is a communications interface which receives the selected signal from the redistributor and delivers it to a receiving device, typically a television set. The communications interface also receives control signals input by the user for transmission to the redistributor to select the chosen input signal.
[21] The disclosure indicates that twisted-pair telephone wire is preferred for sending user-generated control signals upstream from the communications interface to the redistributor, and for sending audio/video signals downstream from the redistributor to the communications interface, though different kinds of conductors (e.g. coaxial cable) may be used. The term “twisted pair” refers to the typical arrangement of wires that has been used for telephone communication for many years. The twisted pair comprises two wires that have been manufactured in an arrangement twisted around one another. At least for frequencies in the range of a human voice, the twisting permits the telephone signal to be transmitted over longer distances than would otherwise be the case. The system described in the 477 Patent uses two twisted pairs, described as red/green and yellow/black. This is typical.
[22] The redistributor of the preferred embodiment is shown in Figure 1 of the 477 Patent, which is reproduced here:
[23] The various input signals are shown on the left, each being received by a separate demodulator which tunes to the appropriate channel of its input (if more than one channel is received), and processes the audio and video signals from each modulator into a common format (baseband). The baseband signal is then injected into a processor (a separate processor for each demodulator) which processes the signals for switching by a cross point matrix switcher. The processors also receive upstream user-generated control signals from the communications interface and output them to a server. The server, through data buses A, B and C, functions as a router to control and route the input signals.
[24] The audio/video signals output from the cross point matrix switcher are transmitted to the communications interface where it is processed to be shown on a receiving device, preferably a television set. User control signals are received at the communications interface via a photoreceptor from a common handheld infrared or wired remote control device. Those signals are sent upstream to the redistributor over a twisted pair of a telephone wire in a manner that does not interfere with the telephone service.
[25] The parties are agreed that the input audio/video signals that are received by the redistributor may be in either analog or digital format. The parties are also agreed that, in the preferred embodiment, the signals output from the demodulator, and subsequently processed for switching and transmitted to the communications interface, are described only as being in analog format, though digital audio/video signals were well-known at the time. Nothing in the patent explicitly excludes digital audio/video signals.
III. Issues in Dispute [26] Following the various admissions and new arguments made by the parties, I have prepared the following list of issues that remain to be decided:
Claim construction
“audio/video signals” “conductors” “server” “controlling an output channel selection of the input signal” “for each communications interface, a switching device”
Infringement – stand-by utility of Fibe TV service only, and claims 1, 2, 4 and 18 only Validity
Anticipation Obviousness Overbreadth/Insufficiency Inutility
Costs
The Corrected Information Bell’s allegation that the plaintiffs are patent trolls Bell’s citation of 753 prior art references in its counterclaim of invalidity of the 477 Patent The plaintiffs’ infringement allegations in respect of Bell Aliant, including maintaining said allegations (i) in respect of FTTH customers until December 2015, and (ii) against all remaining FibreOp TV customers until day 14 of the trial The plaintiffs’ infringement allegations in respect of Bell Canada, including maintaining said allegations, except for the vestige infringement argument based on stand-by utility, until oral submissions on closing argument The plaintiffs’ allegations in support of their claim for punitive damages, and their maintenance of these allegations until day 14 of the trial
IV. Witnesses [27] Brief descriptions of each of the witnesses at trial, together with an overview of their testimony, are provided in the Appendix at the end of these reasons. By way of overview, I have the following non-exhaustive set of observations concerning the witnesses:
One expert witness on each side (Dr. Eldering for the plaintiffs and Dr. Houh for Bell) was an experienced expert witness whose testimony was clear and precise, but whose answers in cross-examination betrayed a certain lack of neutrality. In the end, I favoured Dr. Houh’s testimony because I found his conclusions and his reasoning easier to accept. One of the plaintiffs’ expert witnesses, Dr. Ramakrishnan, prepared his report on claim construction before he was given any information about Bell’s allegedly infringing systems. He was thus kept blind to extraneous facts when construing the claims of the 477 Patent. The plaintiffs argue that I should favour the testimony of such a blinded witness over that of Bell’s experts, who were not blinded. On this subject, I commend the reader to my comments in Shire Canada Inc v Apotex Inc, 2016 FC 382 at para 42 and following. In short, I stated that blinding a witness may indeed lend weight to their testimony in some situations, but I am mainly interested in how well-reasoned the various experts’ opinions are. I agree with the plaintiffs’ argument that construing a patent is for the judge, and the role of the experts is to assist in that analysis. The principals of both of the plaintiffs testified, but the bulk of their testimony became irrelevant once the plaintiffs withdrew their claim for punitive damages. The inventor’s testimony relied heavily on his uncorroborated recollections concerning dates, which were shown to be unreliable. I found all of Bell’s fact witnesses to be credible.
V. Claim Construction A. Applicable Law [28] Claims construction is antecedent to consideration of both validity and infringement issues: Whirlpool Corp v Camco Inc, 2000 SCC 67 at para 43 [Whirlpool].
[29] A patent is not addressed to an ordinary member of the public, but to a worker skilled in the art described as:
a hypothetical person possessing the ordinary skill and knowledge of the particular art to which the invention relates, and a mind willing to understand a specification that is addressed to him. This hypothetical person has sometimes been equated with the “reasonable man” used as a standard in negligence cases. He is assumed to be a man who is going to try to achieve success and not one who is looking for difficulties or seeking failure.
(See Free World Trust v Électro Santé Inc, 2000 SCC 66 at para 44 [Free World Trust], quoting from Fox, Harold G, The Canadian Law and Practice Relating to Letters Patent for Inventions, 4th ed (Toronto: Carswell, 1969) at 184).
[30] The person skilled in the art may also be a team of people: Pfizer Canada Inc v Pharmascience Inc, 2013 FC 120 at para 28; General Tire & Rubber Company v Firestone Tyre and Rubber Company Limited, [1972] RPC 457 at 482 (Eng CA) [General Tire & Rubber].
[31] As stated in Catnic Components Ltd v Hill & Smith Ltd, [1982] RPC 183 at 242-243, and quoted in Whirlpool at para 44:
A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even though it could have no material effect upon the way the invention worked.
[Emphasis in original.]
[32] The claims language will, on a purposive construction, show that some elements of the claimed invention are essential while others are non-essential. Identification of elements as essential or non-essential is made:
(i) on the basis of the common knowledge of the worker skilled in the art to which the patent relates;
(ii) as of the date the patent is published;
(iii) having regard to whether or not it was obvious to the skilled reader at the time the patent was published that a variant of a particular element would not make a difference to the way in which the invention works; or
(iv) according to the intent of the inventor, expressed or inferred from the claims, that a particular element is essential irrespective of its practical effect;
(v) without, however, resort to extrinsic evidence of the inventor's intention.
[Free World Trust at para 31.]
[33] Claim elements are presumed to be essential, and a party alleging otherwise bears the onus of establishing non-essentiality. The Supreme Court of Canada (SCC) in Free World Trust at para 55 stated:
For an element to be considered non-essential and thus substitutable, it must be shown either (i) that on a purposive construction of the words of the claim it was clearly not intended to be essential, or (ii) that at the date of publication of the patent, the skilled addressees would have appreciated that a particular element could be substituted without affecting the working of the invention, i.e., had the skilled worker at that time been told of both the element specified in the claim and the variant and “asked whether the variant would obviously work in the same way”, the answer would be yes: Improver Corp. v. Remington, [[1990] F.S.R. 181], at p. 192. In this context, I think “work in the same way” should be taken for our purposes as meaning that the variant (or component) would perform substantially the same function in substantially the same way to obtain substantially the same result. In Improver Corp. v. Remington, Hoffmann J. attempted to reduce the essence of the Catnic analysis to a series of concise questions, at p. 182:
(i) Does the variant have a material effect upon the way the invention works? If yes, the variant is outside the claim. If no: –
(ii) Would this (i.e.: that the variant had no material effect) have been obvious at the date of publication of the patent to a reader skilled in the art? If no, the variant is outside the claim. If yes: –
(iii) Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention? If yes, the variant is outside the claim.
[34] The foregoing questions are sometimes referred to as the Improver questions. It is understood that a party seeking to establish that a claim element is not essential (i.e. that the variant falls within the scope of the claim) must be successful on all three questions.
[35] In construing the claims of a patent, recourse to the disclosure portion of the specification is (1) permissible to assist in understanding the terms used in the claims, (2) unnecessary where the words are plain and unambiguous, and (3) improper to vary the scope or ambit of the claims: Mylan Pharmaceuticals ULC v Eli Lilly Canada Inc, 2016 FCA 119 at para 39 [Mylan]; Beecham Canada v Procter & Gamble Co (1982), 61 CPR (2d) 1 at 11, [1982] FCJ No 10 (QL) (FCA).
[36] Terms used in the claims must be read in the context of the patent as a whole, and it is therefore unsafe in many instances to conclude that a term is plain and unambiguous without a careful review of the specification: Whirlpool at para 52, quoting from William L. Hayhurst, “The Art of Claiming and Reading a Claim”, in Gordon F. Henderson, ed, Patent Law of Canada (Toronto: Carswell, 1994) at 190.
[37] Because there is potential for tension between the guidance provided in the preceding two paragraphs, I reproduce here the discussion of Justice Russell Zinn in Janssen-Ortho Inc v Canada (Health), 2010 FC 42 at paras 115-116, 119, on this point, with which I agree:
[115] In my view, the whole of the specification (including the disclosure and the claims) may be examined to ascertain the nature of the invention. Where the words of the claims are plain and unambiguous and capable of only one interpretation by a person skilled in the art, recourse to the disclosure is unnecessary. This is not to say that the interpreter should not examine the disclosure. In my view, one should do so, but with caution. Recourse may be had to the disclosure for the purpose of confirming the interpretation arrived at from examining the claims alone or to disclose an ambiguity in the language of the claims that was not otherwise evident. However, the patentee cannot expand the monopoly specifically expressed in the claims by borrowing phrases from the disclosure and placing them into the language of the claims.
[116] I agree with Novopharm that when one looks beyond the language of the claims at issue one ought first look at the dependent claims as an aid to interpreting the independent claims, before one resorts to the disclosure.
[…]
[119] I do not take the Supreme Court of Canada to be saying that in every case one must examine the disclosure prior to construing the claims of the patent; rather, I take the Court in Whirlpool and Free World Trust to be raising a caution that one should not reach a firm conclusion as to the meaning of the words in the claims being construed without having tested one’s initial interpretation against the words of the disclosure. When that is done, if the disclosure suggests another interpretation of the terms used in the claims, then resort to the meanings given in the disclosure is proper, subject to the proviso that the invention that is protected is what is expressed in the claims which cannot be added to by anything mentioned in the disclosure that has not found its way into the claims as drafted. As was noted by Justice Taschereau in Metalliflex Ltd. v. Rodi & Wienenberger Aktiengesellschaft, [1961] S.C.R. 117, at p. 122:
The claims, of course, must be construed with reference to the entire specifications, and the latter may therefore be considered in order to assist in apprehending and construing a claim, but the patentee may not be allowed to expand his monopoly specifically expressed in the claims “by borrowing this or that gloss from other parts of the specifications”.
B. Person Skilled in the Art [38] For the most part, the experts do not disagree substantially as to the characteristics of the skilled person to whom the 477 Patent is addressed. The exception is Dr. Ramakrishnan who was something of an outlier. The experts’ respective descriptions of the characteristics of the skilled person are as follows:
Dr. Eldering:
The person skilled in the art is a person that has at least a bachelor's degree in electrical or computer engineering and several years of experience in the cable and telecommunications industry relating to the design, manufacture, or utilization of equipment for and architecture of communications systems.
Dr. Ramakrishnan:
In my opinion, the reader of the patent (person skilled in the art) would be represented by a team that includes a physical layer network engineer and a network architect familiar with the concepts of the delivery of data generally known in 2000. I would expect that these team members would include persons having post graduate degrees and at least 5 years of experience in evaluating network technology, system integration, evaluating performance of networks.
Dr. Jones:
The ‘477 Patent is directed to a team of people including a network engineer with experience working for a telco or telco lab. Each of these people would need an undergraduate degree in engineering but would not necessarily be a detail-level network designer. The skilled person has at least three years working experience and would be familiar with the operation of a telecommunications network.
Dr. Houh:
In my opinion, the ‘477 Patent is directed to a team of people including an electrical engineer, a computer engineer, a telecommunications specialist, and a broadcast engineer. The team of people would be familiar with audio and video signals and their transmission. Each of these individuals would have either an electrical engineering or computer science undergraduate degree (or equivalent training) and a couple of years of experience working in their field.
Mr. Weeks:
it is my opinion that the ‘477 Patent is directed to a team of people, including someone with an undergraduate degree in network engineering or related engineering field having at least two years of experience working with audio/video transmission over communications networks.
[39] Dr. Ramakrishnan is the only expert who expects that, in addition to experience in the relevant technology, the skilled person (or rather team of skilled persons) have post-graduate degrees. In addition, Dr. Ramakrishnan focuses on the network aspect of the subject matter more than any other expert. In my view, though experience in telecommunications is important in understanding and implementing the invention described in the 477 Patent, and though a team of people may be required to assemble the necessary skills, the subject matter is not so complex or advanced as to require a post-graduate degree. I prefer the views of the other experts on the subject of the skilled person.
[40] In my view, the skilled person in respect of the 477 Patent is a team including an electrical engineer, a computer engineer, and a network engineer having bachelor’s degrees and several years of experience with the design and operation of telecommunications systems.
C. Analysis [41] All of the claim construction issues in dispute concern terms used in claim 1which is reproduced here for convenience:
1. A system for redistributing a plurality of audio/video signals to a plurality of communications interfaces over conductors, comprising
a server,
a redistributor for receiving a plurality of input signals, comprising
for each input signal, a demodulator for demodulating the signal, the server controlling an output channel selection of the input signal responsive to one or more control signals input into the communications interface,
for each communications interface, a switching device for routing the channel selection to an output of the redistributor, the switching device being controlled by the server responsive to one or more control signals input into the communications interface and transmitted to the redistributor over a twisted pair of a telephone wire which carries a telephone signal, and
for each demodulated input signal, a processor for processing the signal for switching,
wherein the communications interface receives the output of the redistributor for transmission to a receiving unit connected to the communications interface.
[42] To paraphrase, claim 1 of the 477 Patent defines a system for redistributing many input signals to many communications interfaces. The input signals are received at a redistributor which has, for each input signal, a demodulator and a processor for, respectively, demodulating the input signal and then processing it for switching. The redistributor also has, for each communications interface, a switching device which routes a selected channel of the input signal to an output of the redistributor to be received by the communications interface. The channel selection is made in response to control signals that are input into the communications interface and transmitted to the redistributor. The control signals are transmitted over a twisted pair of a telephone wire.
[43] My discussion of the various claim elements in dispute is provided in the following paragraphs.
(1) “audio/video signals” [44] Claim 1 of the 477 Patent defines audio/video signals that are received by the redistributor (input signals), demodulated by the demodulator (demodulated input signal), processed for switching (output of the redistributor), and received by the communications interface. The parties are agreed that the input signals may be in analog format or digital format.
[45] The key question here is whether the demodulated input signal and the output of the redistributor encompasses digital signals or is limited to analog signals as described in the 477 Patent.
[46] The plaintiffs argue firstly that the claim language itself does not mention either analog or digital and therefore does not exclude digital signals. The plaintiffs argue that a limitation to analog signals should not be read in to claim 1. The plaintiffs also point to wording in the disclosure of the 477 Patent that they argue indicates that both digital and analog signals are contemplated: “The system of the invention may be equipped to receive and redistribute any video or audio/video signal in any format … and the invention is not intended to be limited to the specific types of signals illustrated and described below.” The plaintiffs note that it is undisputed that both the input signals received by the various demodulators in the redistributor and the user control signals sent upstream from the communications interface may be digital. The plaintiffs argue that the demodulated and processed audio/video signals sent downstream should be treated no differently. Finally, the plaintiffs argue that the common general knowledge of the skilled person should be considered. They note that it is undisputed that digital audio/video signals were well-known and that it was understood that they would eventually displace analog signals.
[47] With regard to the passage quoted from the 477 Patent in the previous paragraph (“…to receive and redistribute any video or audio/video signal in any format…”), Bell argues that the audio/video signal referred to is the input signal received by the redistributor rather than the demodulated input signal or the output of the redistributor. It is these input signals that are discussed at length immediately after the phrase “the specific types of signals illustrated and described below”. It is these input signals that are contemplated as being in either analog or digital format. Bell also notes that many of the terms used to describe the processing of audio/video signals are particular to analog: e.g. equalizing the high frequency components and changing the level of the chroma.
[48] Reading claim 1 alone, there is nothing that suggests that the term “audio/video signals” generally, or the terms “demodulated input signal” or “output of the redistributor” specifically, are intended to be limited to analog signals. That is to say, nothing in claim 1 excludes digital signals. However, this initial view is put into question upon considering claim 3 which depends from claim 1 and adds the following limitation:
the processors match the impedance of the demodulated input signal to the output impedance of the redistributor, raise the baseband of the demodulated input signal, equalize the high frequency components and increase the level of chroma of the demodulated input signal, and increase the peak-to-peak voltage of the demodulated input signal.
[49] As noted by Bell, steps such as equalizing the high frequency components and increasing the level of the chroma are particular to the processing of analog signals. This suggests that the demodulated input signal and the output of the redistributor of claim 1 are necessarily analog. It certainly gives rise to enough ambiguity in this term to justify recourse to the disclosure in order to assist in understanding its scope.
[50] Upon review of the disclosure, the skilled person sees only reference to analog audio/video signals after demodulation. The disclosure even provides for the demodulators that are receiving digital input signals to decode them into analog form. There is no suggestion that any audio/video signals could be in digital form after demodulation.
[51] With regard to the plaintiffs’ argument that the skilled person was well aware of the existence of digital signals, this appears in fact to be an additional reason to read claim 1 narrowly. The focus uniquely on analog signals, and the failure to make even the slightest suggestion of digital signals being output from the demodulators or the processors and sent downstream from the redistributor to the communications interface, suggest that the inventor contemplated only analog signals at this stage. This is in stark contrast with the input signals which are shown in digital and analog formats and repeatedly described as being in “any format”. In fact, a main thrust of the invention is the gathering in one place of a plurality of input signals having different formats and putting them into a common format.
[52] Putting this issue in the terms of the Improver questions listed in paragraph [33] above, and particularly the third question, it is my view that the reader skilled in the art would have understood that the patentee contemplated only analog formats for the demodulated and processed audio/video signals.
[53] Therefore, I conclude that the “audio/video signals” defined in claim 1 are limited to analog signals after demodulation. Digital signals are not within the scope of claim 1.
(2) “conductors” [54] The word “conductors” appears in the preamble of claim 1 and defines the medium over which audio/video signals are redistributed. The parties are agreed that the word is to be construed broadly, and includes twisted pairs and coaxial cables. In fact, the parties are agreed that it should be construed broadly enough to encompass even other means of communication such as fibre optic cables which are not normally considered to be conductors.
[55] The issue in dispute with regard to “conductors” is whether it can include the same “twisted pair of a telephone wire which carries a telephone signal” as is defined later in claim 1 as the medium for carrying control signals from the communications interface to the redistributor. In other words, does claim 1 encompass audio/video signals that travel downstream over the same twisted pair as the control signals use to travel upstream?
[56] Bell argues that the use in claim 1 of the different terms “conductors” and “twisted pair of a telephone wire which carries a telephone signal” suggests that they are intended to be distinct. Bell also focuses on portions of the disclosure of the 477 Patent which suggest that a single twisted pair is generally unsuitable for carrying both downstream audio/video signals and upstream control signals. Specifically, where two separate twisted pairs are not available, the disclosure does not suggest that signals be carried in both directions on the same twisted pair. Rather, it suggests using the building ground as a common ground to permit the invention to operate effectively over a single twisted pair by having audio/video signals travel downstream on one wire of the twisted pair and user control signals travel upstream on the other wire of the twisted pair. Also, in addressing the situation of an individual unit (or user) having more than one television receiver, the disclosure suggests that extra twisted pairs may be employed, and states that “an eight pair twisted cable can support up to four separate television receivers 2 in a unit, each television receiver using one pair for incoming and outgoing audio/video signals and another pair for transmitting control signals to the redistributor 8.” It is implicit in this statement that each television requires two twisted pairs.
[57] The plaintiffs respond that the word “conductors” is broad and nothing in claim 1 suggests that it cannot encompass the same twis