Hershkovitz v. Tyco Safety Products Canada Ltd.

Hershkovitz v. Tyco Safety Products Canada Ltd.
Court (s) Database
Federal Court Decisions
Date
2009-03-12
Neutral citation
2009 FC 256
File numbers
T-426-04
Notes
Digest
Decision Content
Date: 20090312
Docket: T-426-04
Citation: 2009 FC 256
Ottawa, Ontario, March 12, 2009
PRESENT: The Honourable Mr. Justice Martineau
BETWEEN:
SHMUEL HERSHKOVITZ,
SYSTÈMES DE SÉCURITÉ PARADOX LTÉE
- PARADOX SECURITY SYSTEMS LTD.,
and
PINHAS SHPATER
Plaintiffs
(Defendants by Counterclaim)
and
TYCO SAFETY PRODUCTS CANADA LTD.,
Defendant
(Plaintiff by Counterclaim)
REASONS FOR JUDGMENT AND JUDGMENT
[1] The present concerns the infringement and validity of Canadian Patents No. 2,169,670 (the ‘670 patent) and No. 2,273,148 (the ‘148 patent) and related disclaimers which are reproduced at the end of same.
I. THE PRESENT PROCEEDINGS
[2] The plaintiffs are respectively the present owner and assignee of the patents in suit, Shmuel Hershkovitz (designated as the “patentee” in the disclaimers); its exclusive licensee for Canada, Systèmes de Sécurité Paradox Ltée – Paradox Security Systems (Paradox); and Pinhas Shpater, the named inventor of the particular telephone line coupler circuit and method which are the object of the patents in suit. The defendant, Tyco Safety Products Canada Ltd. (Tyco), formerly Digital Security Controls Inc. (DSC), is a long time competitor of Paradox. Both enterprises manufacture and sell alarm systems for home and business use. They market their products through distributors and not directly to customers. Same are sold in Canada, the United States of America and other countries of the world.
[3] This action was commenced by a Statement of Claim filed on February 27, 2004 claiming infringement and seeking a permanent injunction, damages or an accounting of profits, with interest and costs. Originally, the plaintiffs alleged infringement (direct and by inducement) of all claims of the patents in suit through the manufacture, use and sale of certain alarm panels by the defendant. However, the plaintiffs now allege infringement of claims 1, 2, 5 and 6 of the ‘670 patent and of claims 1 and 2 of the ‘148 patent (the claims in suit). As the plaintiffs have alleged that the defendant’s infringement has been deliberate and wilful, they are also seeking punitive and exemplary damages. The defendant has denied any infringement and has counterclaimed by seeking the invalidity of the patents in suit and related disclaimers.
[4] A bifurcation order was pronounced on September 13, 2004. The pace of proceedings has been slow. The parties are apparently also involved in some parallel litigation in the U.S. The matter was finally heard by the Court in November and part of December 2008. The present action should be dismissed and the counterclaim allowed. The disclaimers are invalid; since the admission made by the patentee that the original claims are too broad, same cannot subsist and the patents in suit are also invalid. In any event, the claims in suit, as disclaimed or prior to the disclaimers, are invalid because they are anticipated, obvious and/or an unpatentable aggregation. In the event of an appeal, the Court’s non-determinative findings with respect to infringement and related issues are also stated in the reasons.
[5] For purposes of convenience, the present reasons will follow the following plan:
Section
Title
Paragraphs
I.
The Present Proceedings
2 to 6
II.
Technical Information
7 to 9
III.
The Patents in Suit
10 to 14
IV.
Chronology
15 to 30
V.
Expert Evidence
31 to 35
VI.
Construction
36 to 72
VII.
Disclaimers
73 to 96
VIII.
Anticipation
97 to 133
IX.
Obviousness
134 to 147
X.
Unpatentable Aggregation
148 to 149
XI.
Infringement and Related Issues
150 to 161
XII.
Conclusion
162
[6] Finally, there is no disagreement between the parties as to the applicable provisions of the Patent Act, R.S.C. 1985, c. P-4 (Patent Act) and nothing turns on this legal issue. The defendant readily acknowledges that on their face, the applications which resulted in the ‘670 and ‘148 patents, and thus to the patents themselves, do not offend subsection 27(2), as it read immediately before October 1, 1996 and the parties agree that all other relevant provisions of the current Patent Act as of October 1, 1996, apply to this matter. Thus, with regard to the allegations of anticipation and obviousness of the patents in suit, sections 28.2 and 28.3 of the current Patent Act apply.
II. TECHNICAL INFORMATION
[7] The public switched telephone network is a natural choice as a means to connect an alarm system to an alarm monitoring centre. Security alarm systems generally include a security panel joined to a modem that provides bidirectional communication over the phone network. The modem conveys security and emergency related data at various connection speeds between the phone network and the security panel. An interface is needed for any terminal which takes data from, and/or sends data, to a telephone line (i.e. modem, facsimile machine, or the like).
[8] The central office (i.e. the local telephone exchange) provides power (typically 48 V DC from a battery feed) and ringing signals to a telephone line. It also provides supervisory functions (detection of dialing, on-hook and off-hook conditions). The telephone line is a balanced two-conductor circuit. The two conductors at the subscriber’s end are identified as “tip” and “ring”. A connection is made when the subscriber telephone (or “subscriber set”) is taken “off-hook”. When taken off-hook, a return path for current generated at the central office is provided in the telephone set. When in the “on-hook” position, the telephone handset presents a relatively high resistance – essentially an open circuit – with no current flow. When the telephone set is in the on-hook state, the central office signals a request for a connection (i.e. an incoming telephone call for the subscriber) with a ringing signal. This signal is an intermittent (2 seconds on, 4 seconds off) high voltage (86 V rms) AC (20 Hz) signal. The AC ringing voltage can be routed (via a capacitor) to an electro‑mechanical bell (as in old telephone sets) or be used to trigger an electronic ring tone to alert the subscriber of the incoming call (as in modern telephone sets). Similarly, the central office can detect the current flow when a telephone handset is taken off-hook by the subscriber and will then provide a dial tone to indicate that it is ready to receive dialing. This act of providing a path for the current flow in the off-hook state “seizes” the line. The amount of DC current flowing depends on the load (resistance) offered by the subscriber set and on the resistance of the subscriber loop which in turn depends on its length (distance between the central office and the subscriber). In North America, the subscriber set can have a maximum resistance of 400Ω. With this maximum resistance, the “subscriber loop” is 21.2mA. Therefore, a current of at least this amount is needed to reliably seize the line.
[9] Once a connection has been established between the central office and the subscriber, either by initiating a call (dialing) or receiving a call (answering a ring), voice communications can begin. The voice signal is an AC signal superimposed on the DC current flowing from the central office. At this point, it is important to note that data devices, such as modems or facsimile machines, which use a “dial-up” connection in order to send and receive data, are limited to the range of frequencies supported by the central office for speech signals. Therefore, the data information is modulated onto a carrier frequency in the middle of the speech band. The resultant electrical signals consist of signals having both positive and negative components. These AC signals must be “biased” by a DC steady current when an opto-coupler is used. Otherwise, the negative portion of such signals would be lost in the process by the opto-coupler (for a definition of an opto-coupler, see paragraph [11] ). Data communications can be “half-duplex” or “full duplex”. In half-duplex, only one end is transmitting at any given time. In some cases, full-duplex transmission is needed. However, for alarm systems, the amount of data to be transmitted is modest and thus half-duplex or split band-approaches (half of the telephone band dedicated to transmission and the other half dedicated to reception) are generally appropriate. In the case of an alarm system, the communication interface works to transfer control from the subscriber phone to the security panel by providing the interface to the phone network by matching impedance levels, ring levels and the like. Moreover, in order to protect the electronic equipment from surges on the telephone line side and to prevent different ground voltages from causing erroneous operation in the subscriber equipment, the latter will also include devices that are able to perform an isolation function (such as opto-couplers or transformers).
III. THE PATENTS IN SUIT
[10] The patents in suit describe a circuit (the ‘670 patent) and method (the ‘148 patent) that permits the following functions to be performed using only two opto-couplers: (i) ring signal detect; (ii) telephone line seize; (iii) communications signal transmit; and (iv) communications signal receive.
[11] Opto-couplers are an old technology. An opto-coupler device consists of two parts in a single package (housing). On the input side, a light-emitting diode (commonly known as a LED) generates light internally. A photo-receptor also within the package is activated by this light. There is no electrical connection between the two halves of the opto-couplers, thus providing the needed isolation between the line side and the subscriber side of the telephone line coupler.
[12] Figure 1 of the ‘670 and ‘148 patents, reproduced below, is a block diagram of the telephone line coupler circuit according to its preferred embodiment:
[13] As can be seen from the figure above, the telephone line side is on the left of the dotted lines while the subscriber side is on the right and the bottom right. The insulation is performed by two opto-couplers: a receive opto-coupler 16 and a transmit opto-coupler 20. (The LED of the receive opto-coupler 16 is on the telephone line side while the LED of the transmit opto-coupler is on the subscriber side. Each diode is symbolized by triangles. The two arrows next to the triangle indicate that it produces light and that it is a light-emitting diode and not just a regular diode). The output of the transmit opto‑coupler 20 includes a DC bias component 22 connected to a gate of a line seize switch 15 for connecting a DC line seize load 14 across the ring and tip contacts 10 and 11 of the telephone line. The receive opto‑coupler 16 is used both for receiving communications signal and for detecting the ring signal. The band pass filter 18 is connected to the output of the receive opto-coupler 16. A diode bridge 12 (providing the correct polarity) is also found in the telephone line coupler circuit.
[14] The disclosed invention is not limited to applications flowing from the use of a telephone line connected to an alarm system.
IV. CHRONOLOGY
[15] For the purposes of this chronology, besides the documentary evidence, the Court has considered the testimonies of all fact witnesses heard at the trial.
[16] In 1989, Shpater and Hershkovitz started a new company in the security sector which became known as Paradox. Following an unrelated infringement dispute with DSC, which was settled out of court, Paradox started to manufacture and sell alarm panels around 1993. These panels were all designed by Shpater. Paradox’s first line of control panels, which was referred to as the 7 X 7 series (including the 747 and 737 control panels), integrated four opto-couplers with a bias circuit on the line side. As a result, a dedicated opto-coupler was used to isolate the components on the line side or on the subscriber side which perform each of the four functions already identified in section II, i.e. ring signal detect, telephone line seize, communications signal transmit and communications signal receive. A fifth opto-coupler was also used for telephone line monitoring (TLM), an application which is not claimed by the patents in suit.
[17] Around 1994-1995, Shpater worked on a new design of telephone line couplers that will use less opto-couplers (such as the next generations of 7 X 8 and 8 X 8 series models later sold by Paradox). His solution will be to use a single opto-coupler for incoming ringing or communication signals, while outgoing communication signals will pass through the other opto-coupler. After some experimentation, Shpater realizes that there is already a very stable source for biasing the receive opto-coupler and it is the transmit opto-coupler. Once the biasing current is on the line side, a transistor device will be used to generate a high voltage permitting the line to be seized. The line seize signal will also control the switching of the band pass filter (which can be switchable between frequencies for ring or communication signals).
[18] Shpater is familiar with patent prosecution. Indeed, over the years, he made some ten applications in Canada and the United States of America. James Anglehart, then a member of Ogilvy Renault, acted as the patent agent for Paradox. Sometime during the fall of 1995, a preliminary patentability search with respect to the use of opto-couplers as isolation devices in a telephone line connector circuit was carried out. The research was limited to the U.S. In their practice, patent agents deal with a substantial number of files. It happened at trial that Anglehart had very little personal recollection of actual events, particularly with respect to the circumstances related to the filing of the disclaimers in Canada and the reissue application in the U.S. His memory essentially remained in the realm of the documents that were produced at trial.
[19] On November 8, 1995, the application that led to U.S. Patent No. 5,751,803 (the ‘803 patent) was filed with the United States Patent and Trademark Office (USPTO). On May 12, 1998, the ‘803 patent issued with four claims. In the meantime, on February 16, 1996, the application that led to the ‘670 and ‘148 patents (the Canadian application) was filed with the Canadian Intellectual Property Office (CIPO) and it became open for public inspection on May 9, 1997. This application claims priority on the U.S. application filed on November 8, 1995. The descriptive and disclosure portions of the Canadian application, including Figure 1 illustrating the preferred embodiment, are virtually identical to their U.S. counterpart. Among U.S. patent documents cited, one finds U.S. Patent No. 4,727,535 which issued on February 23, 1988 (Brandt) and U.S. Patent No. 4,282,604 which issued on August 4, 1981 (Jefferson). Brandt and Jefferson are discussed in detail in the section dealing with anticipation (section VIII).
[20] The Court pauses to mention that while the applications in the U.S. and Canada were still pending, Shpater and Hershkovitz had an important business disagreement which resulted in the dismissal of Shpater, sometime in March 1998. At that time, Shpater’s lawyer approached Paradox’s competitors, including DSC, canvassing to see if there was any interest in buying Shpater’s outstanding interest in Paradox and related inventions. John Peterson, who was owner and president of DSC at that time, remembers having had a telephone conversation with Shpater sometime in April 1998. He listened politely to Shpater and the matter did not go further. Shpater left Canada and returned to Israel, his home country, on May 12, 1998. At the beginning of 1999, Shpater managed to reach an agreement with Hershkovitz. (Full and final payment was completed in 2002, upon which the transfer of rights detained by Shpater in all patented inventions was finalized). There is no need to review here the different assignment and licence documents produced at trial.
[21] On March 22, 1999, a request for examination of the Canadian application, together with a request that the examination be advanced (citing a potential infringer as grounds) was filed, and the claims were amended to include the four claims in the ‘803 patent and to add method claims as well. CIPO granted the request for an advanced examination a month later. On May 21, 1999, an office action was taken by CIPO indicating that it considered that the Canadian application claimed more than one invention and the application should be amended accordingly. On June 17, 1999, a divisional application (which later became the ‘148 patent), was filed; the method claims are included in same. On July 15, 1999, a notice of allowance of the original Canadian application was issued. After payment of the final fee on July 21, 1999, the ‘670 patent issued on October 5, 1999.
[22] On December 8, 1999, through counsel, the owners of the ‘670 patent wrote to DSC asserting their rights in the ‘670 patent and alleging that DSC’s products infringe the patent. On January 14, 2000, DSC denied all allegations of infringement and asserted that the ‘670 patent was invalid due to anticipation and/or obviousness. DSC’s counsel cited prior art including a device referred to as the “Pascom device” and the defendant’s own DSC 4000 device. The Pascom prior art references also included PCT application No. PCT/AU93/00403, published on February 17, 1994 under No. W094/03990 (Pascom) and Australian patent application Nos. PL3955 (Whitby) and PL4052 from which the PCT application claimed priority (collectively, the Pascom references). The plaintiffs did not respond to DSC’s general denial nor did they take any legal action to assert their rights against the defendant for a period of more than four years. Peterson testified that following Paradox’s silence after the January 14, 2000 letter, he thought this was the end of the matter. He sold his company to Tyco in 2001.
[23] Although the plaintiffs admit today that the Pascom references and the DSC 4000 are relevant prior art, this was not the original position they took. According to the evidence, between 2000 and 2004, strategic steps were taken by the plaintiffs, concurrently in the U.S. and Canada, to enhance their legal position in an infringement action against potential infringers, – notably the defendant. A key element of plaintiffs’ strategy, was the filing of an application for reissue of the ‘803 patent on May 12, 2000 with the USPTO. Same was apparently made on the grounds that the patentee wanted to add method claims and that he had claimed less than he had the right to claim.
[24] According to the evidence, the plaintiffs also voluntarily choose in Canada:
(a) not to disclose newly discovered prior art to CIPO (DSC 4000 and Pascom) during the prosecution of their divisional application; and,
(b) not to make any amendment to the divisional application by adding the language that will later be made by disclaimer;
(c) not to file an application for reissue of the ‘670 patent while actively pursuing an application for reissue of the ‘803 patent.
[25] Although these important patent prosecution decisions were apparently taken by Hershkovitz himself, he did not remember anything at the trial. Simply, if there were any patent documents that needed to be signed by him (including the disclaimers), he would sign them. Hershkovitz testified that Anglehart and Shpater were better placed than him to answer questions on patent prosecution. At the time, Shpater had already left Paradox but had offered to assist with patent related matters. Anglehart sought Shpater’s technical opinion at occasions.
[26] In Canada, while the U.S. application for reissue was still pending, Paradox paid the final fee on April 8, 2002 to the CIPO. The divisional application matured to the ‘148 patent on June 25, 2002. A few days afterwards, on July 11, 2002, Paradox responded to the first office action of the U.S. Examiner, who had already indicated on January 11, 2002 that the U.S. claims were anticipated or obvious in light of Pascom who already had a two opto-coupler design. Not satisfied by Paradox’s representations, the U.S. Examiner issued a second office action on November 5, 2002. Again, all claims of the U.S. reissue application were rejected in light of the Pascom references. On March 17, 2003, Anglehart, Ron Toledano, Vice-President for Paradox Security Systems (and also counsel for the company) and Sylvain Cormier, then employed by Paradox as hardware designer, had a face to face meeting with the U.S. Examiner, Jacky Chang. On August 7, 2003, in an attempt to distinguish Pascom who had a “parallel connection” between the two opto-couplers, Paradox purportedly narrowed the scope of all claims of its reissue application, including all independent claims, by adding a “series connection” limitation. An appeal was filed.
[27] On October 6, 2003, disclaimers were filed in Canada in relation to the patent in suit. The disclaimers state that the patentee has made a specification “too broad” and disclaim all of the independent claims of the ‘670 and ‘148 patents by purportedly seeking to add limitation language to the effect that the receive and transmit opto-couplers are connected “in series … on a telephone side to draw a minimum of current to place a light-emitting diode of [the] receive opto-coupler in an operational range.” Anglehart signed the disclaimers on behalf of Hershkovitz. Anglehart testified that it was on instructions from counsel that the disclaimers were filed. Incidentally, the filing of the disclaimers is made only one day after the expiry of the delay to file an application for reissue in Canada (the four year limitation period). Be that as it may, Anglehart cannot remember if a meeting was called with Hershkovitz or Shpater to discuss the disclaimers or other available options (such as an application for reissue in Canada). That said, Cormier reviewed the technical wording of the addition now found in the disclaimers prepared by Anglehart. However, Cormier was not personally involved in any decision making and was not permitted at trial to testify on the state of mind of the patentee or the assignee. On December 5, 2003, CIPO advised Paradox that the disclaimers had been recorded.
[28] On January 12, 2004, the U.S. Examiner issued a notice of allowance of the U.S. reissue application, based on the above “in series” modifications made by Paradox. On February 11, 2004, Paradox demanded that DSC cease sales of its allegedly infringing products, this time based on the newly disclaimed patents. Sixteen days after this demand letter, Paradox filed the within proceedings. On April 19, 2004, Tyco filed and served its Statement of Defence and Counterclaim regarding this matter. Tyco’s defence and counterclaim is based on the already mentioned Pascom and DSC 4000 reference, as well as additional relevant prior art.
[29] On April 23, 2004, four days after the service of Tyco’s defence and counterclaim, Paradox filed with the USPTO:
(a) a Request for Continued Examination of its U.S. reissue application;
(b) a Petition to withdraw the application from issue based on the prior art cited by Tyco in its Statement of Defence and Counterclaim; and
(c) a second Information Disclosure Statement disclosing the prior art cited by Tyco in its Statement of Defence and Counterclaim (including the DSC 4000 schematic).
[30] As a result of the above actions by Paradox, the U.S. notice of allowance was withdrawn and the prosecution of the U.S. application was once more reopened. While the U.S. reissue patent was granted on November 21, 2006, it is now subject to re-examination.
V. EXPERT EVIDENCE
[31] There was no challenge at trial regarding the qualifications and expertise of the plaintiffs’ expert witnesses, Randy Brandt and Leonard MacEachern, the latter being heard in rebuttal to the defendant’s expert, Peter Kabal, whom the Court also found qualified. There was no substantial amendment made by Brandt to his original expert report (Exhibit P-209) and his rebuttal expert report of November 30, 2007 (Exhibit P-210). In addition to their original reports, Kabal and MacEachern produced at trial revised versions of same on November 1 and 23, 2008, respectively. MacEachern’s revised rebuttal report (Exhibit P-275) mostly comments the changes and additions made by Kabal in his revised report (Exhibit D-246). In their reports and at trial, experts gave their opinion as to the meaning of an ordinary person skilled in the art would ascribe to the various technical terms used in the patents in suit and/or in the prior art. Experts also testified on technical aspects related to the functioning and operating of various components which would be used by such person skilled in the art who would want to make the invention disclosed in same. In its final analysis, the Court has preferred expert opinion that accords with the totality of the evidence, or with the terms of the patents in suit as construed by the Court, and having regards to the clarity and convincing character of the answers provided by the respective experts who were subjected to long cross-examinations at trial.
[32] It became apparent during Kabal’s cross-examination that the claim chart that was included as an annex in Kabal’s original report, dated April 27, 2007, and which summarizes where particular elements of the claims in suit are found within the various pieces of prior art cited above, was provided to him by defendant’s counsel before he wrote his report. As noted by Justice Mosley in Dimplex North America Ltd. v. CFM Corporation, 54 C.P.R. (4th) 435, at page 449, one can “doubt that there are many expert reports that are not, to some extent, the product of collaboration between counsel and the expert if only to conform to varying legal requirements in different jurisdictions or to focus the report on the issues.” A simple reading of the respective reports produced by the parties’ experts highlight this collaboration with counsel. In the case at bar, despite the fact that the chart produced with Kabal’s report may have been prepared by somebody else, it became abundantly clear during his testimony that the validity analysis was entirely his own.
[33] At trial, both Brandt and Kabal were always candid, forthcoming and ready to recognize promptly any error they may have made (notably in respect of circuit analysis). Conversely, MacEachern showed perhaps a greater textbook knowledge than Brandt and Kabal in the field of analog circuits and took a more tutorial approach with the Court, but he also showed a great reluctance to amend himself, even if it appeared that his opinion was questionable or that another interpretation was possible. Having said that, the Court has not ignored objective facts such as changes of opinion of expert witnesses as that may pertain to credibility. Many of the changes or additions made in the revised version of Kabal’s report are substantive. On the other hand, same were volunteered prior to trial by Kabal himself which attests of his good faith and accorded with his understanding of the technology at issue. Thus, the Court was not ready to outright ignore Kabal’s revisions, preferring to evaluate same after hearing Kabal and MacEachern’s testimonies and considering MacEachern’s revised rebuttal report.
[34] At trial, all three expert witnesses also had some difficulty with the fact that the patents in suit are only general block diagrams. This makes it impossible for the experts and persons skilled in the art to actually measure the current, the voltage and the resistance at any point of reference of the circuit described in the patents in suit. However, it was recognized by the experts that a person skilled in the art who has read the patents in suit would favour components that will normally operate near the middle of the range indicated on the specification sheet of the chosen component. This is so, unless the patents teach otherwise.
[35] Besides the DSC 4000 device (Exhibit P-206) itself, and the Brandt (J-70) and Pascom (J‑64) references, which are relevant as well, in support of its arguments of invalidity on the basis of anticipation and/or obviousness, the defendant relied on a number of other published references, all of which the defendant submits represent relevant prior art for the patents in suit. Indeed, the Court has also found all these additional references, relevant prior art:
- Japanese patent application JP S5586253, published on June 28, 1980
(Toshiba) (J-73);
- U.S. patent no. 4,282,604, issued on August 4, 1981 (Jefferson) (J-69);
- Application JPS61030847, published on February 13, 1986 (Ricoh) (J-74);
- PCT application WO94/06215, published on March 17, 1994 (Roberts) (J-71);
- PCT application WO94/07319, published on March 31, 1994 (Agbaje-Anozie)
(J-72).
For the purposes of sections 28.2 and 28.3 of the Patent Act, all the above references (including the DSC 4000 device) are thoroughly examined at sections VIII and IX. (However, defendant’s closing submissions make no argument based on Ricoh. Accordingly, Ricoh is not addressed in these reasons).
VI. CONSTRUCTION
A. General Principles
[36] Construction of claims is the first step in a patent suit. It is antecedent to consideration of both validity and infringement issues. Applicable rules have been defined extensively by the case law, especially by the Supreme Court of Canada in Consolboard Inc. v. MacMillan Bloedel (Sask.) Ltd., [1981] 1 S.C.R. 504, Whirlpool Corp. v. Camco Inc., [2000] 2 S.C.R. 1067, and Free World Trust v. Electro Santé Inc., [2000] 2 S.C.R. 1024 (Free World). The Patent Act seeks both fairness and predictability. Predictability is achieved by tying the patentee to its claims while fairness is achieved by interpreting those terms in an informed and purposive manner.
[37] That said, the Court must interpret the claims, it cannot redraft them. If the inventor has created an unnecessary or troublesome limitation in the claims, it is a “self-inflicted wound”. Indeed, the public is entitled to rely on the words used in the patent provided that they are interpreted fairly by the Court. Purposive construction requires the identification by the Court, with the assistance of the skilled reader, of the particular descriptive words or phrases in the claims that describe “essential elements”. The construction of the claims is the same for both validity and infringement. The language of the patent should be construed as of the date of publication of the patent without resort to extrinsic evidence of the inventor’s intention. Where necessary, the whole of the patent, and not only the claims, should be construed. Reference to patent drawings will sometimes clarify what is meant by a claim but should not be used to supplement a claim by adding new inventive elements.
B. Person of ordinary skill in the art
[38] A patent specification (including the claims) is not addressed to a member of the general public; it is directed to a “person of skill in the art” to which the patent relates. The “ordinariness” of the person skilled in the art will vary with the subject matter of the patent. Such a person possesses the ordinary amount of knowledge incidental to his field and is thought to be reasonably diligent with keeping up with the advances in the field. In the case at bar, the Court accepts that a person of ordinary skill in the art is likely to have a bachelor degree in electrical engineering (or related technical discipline) with a few years of experience in electronics as applied to the implementation of telephony circuits. A person having a lower degree of education, such as a technician, would not fit in the profile of a person skilled in the art for the purpose of this case, unless he has acquired several years of practical experience designing similar telephony circuits. As such, the person skilled in the art would have developed satisfactory knowledge about electrical design, electronics and telephony. He would have a thorough understanding of electrical engineering principles in association with telephony signaling schemes, including data transmission and transmission line considerations.
C. Disclosure
[39] The ‘670 patent is entitled “Telephone Line Coupler”. It issued on October 5, 1999 based on an application filed on February 2, 1996 which claimed priority on a U.S. application filed on November 8, 1995. It became open for public inspection on May 9, 1997. The ‘148 patent is likewise entitled “Telephone Line Coupler”. It was filed on June 17, 1999 as a divisional application of the ‘670 patent. Because of its status as a divisional patent, it is deemed to have been filed on February 2, 1996, to have become open for public inspection on May 9, 1997, and to benefit from the November 8, 1995 priority date, like the ‘670 patent. The ‘148 patent issued on June 25, 2002. That said, disclaimers in relation to each of the patents in suit were filed on October 6, 2003. These disclaimers were recorded as confirmed by letters from CIPO dated December 5, 2003.
[40] The relevant date for the construction of the language used in the patents in suit is May 9, 1997. The descriptive portions of the two patents in suit are virtually identical. In the interpretation of the claims in suit, in light of the expert evidence adduced at trial, the Court has sought guidance from the patent specification. Unfortunately, it is not very useful for this task. It often uses exactly the same language as the claims, thus shedding little, if any, new light on the claims.The lack of specificity and discussion of prior art in the disclosure section of the patents in suit is striking compared to many of the prior art documents produced at trial.
[41] It is asserted in the disclosure part of the patents in suit that coupler circuits which use opto-couplers, are known in the art. Reference is made in this regard to Brandt and to U.S. Patent No. 4,203,006 (Mascia). In Brandt, a coupler circuit is described in which a single opto-coupler is used for relaying the analog AC transmit signal and another opto-coupler device is used for relaying the received AC signal. In Mascia, one opto-coupler is used for relaying a ringing signal to a modem, a second opto-coupler is used in relaying a line seize signal from the modem to the telephone line access coupler and a transformer is used in place of a pair of opto-couplers for relaying the received and transmitted AC signals from the coupler to the modem.
[42] The disclosure section of the patents in suit and the expert evidence are to the effect that transformers can also be used to perform the isolation function in a telephone line coupler. Indeed, the bi-directional nature of the transformer allows for a single device to be used for relaying the received and the transmitted communication signals (as in the Mascia patent). However, contrary to a transformer, an opto-coupler is not bi-directional. It is therefore asserted in the disclosure part of the patents in suit that, in the known prior art, the basic functions of relaying the AC transmit signal all require separate opto-coupler devices, in this case, four opto-couplers. (We will see later in these reasons that this assumption proves to be wrong in fact). The telephone line coupler circuit described in the patents in suit uses only two opto-couplers (instead of four opto-couplers). It is stated by the inventor that this results in cost savings because of the reduced number of opto-couplers required.
[43] Although referred to in the summary of the invention, there are references to devices or parameters, apparently important in the functioning of the invention but which, unfortunately, are not defined or explained, such as a “high impedance DC load”. Another instance of incertitude concerns certain aspects of the claimed method disclosed in the summary of the invention, such as the reference to “the DC bias being sufficient to generate a low level DC output on a line side of the transmit opto-coupler” (page 4a, lines 2 to 4). The expert evidence on record suggests that cost savings seem to be a major consideration and that in this respect, a high level DC output could be substituted to a low level DC output.
[44] Figure 1 of the ‘670 and ‘148 patents is a block diagram of the telephone line coupler circuit according to the “preferred embodiment”. It is already reproduced in paragragh [12] of these reasons. It shows six blocks which are only partially alluded or elaborated upon in the disclosure section. According to the expert evidence heard by the Court, there are four paths of current corresponding to the four functions described in the patents in suit. For the purpose of claims construction, it is not necessary to go into a technical analysis of the current flow in the telephone line coupler circuit. The actual physical components and values needed to work the invention are not disclosed in the patents. Some components are directly related to the isolation function (such as the opto-coupler 16 and 20). Others have not had an effect on the functioning of the telephone line coupler (such as the diode bridge 12 or the regular diode 17). Therefore, some “trial and error” by the person skilled in the art would therefore be necessary before the invention actually works (for example, to set the proper biasing DC current).
[45] In the preferred embodiment, the receive opto-coupler 16 is connected to the transmit opto-coupler 20 such that a minimum draw of current to place the light-emitting diode of receive opto-coupler 16 in an operational range is achieved. As will be seen, no such connection is claimed in any of the original claims in suit. Moreover, even though the opto‑couplers 16 and 20 are shown attached “head to tail” in Figure 1, based on the reading of the specification as a whole, including the claims prior to the filing of the disclaimers, and having considered the expert evidence, it would not be clear to a person ordinary skilled in the art that it is essential to connect the receive and transmit opto-couplers “in series” to work the invention. Indeed, during his testimony, Brandt suggested that a “parallel connection” would work as well.
D. Apparatus claims
[46] The invention for which exclusivity is claimed by the ‘670 patent relates to a telephone line coupler circuit. The claimed purpose of this circuit is “for connecting telephone subscriber equipment to a telephone line”. Claims 1, 2, 3 and 4 of the ‘670 patent are independent claims, while claims 5 and 6 are dependent claims.
[47] Each patented circuit is comprised of a number of physical components carrying on specific functions and connected together in a particular manner, as the case may be. The elements in claims 1 and 2 are virtually identical, except that claim 1 refers simply to an “AC signal receive means” while claim 2 refers to both an “AC communications signal receive means” and an “AC ring signal detect means”, wherein those two elements share “a common receive opto-coupler device”. This particular feature is not found in claim 1 who is certainly broader than claim 2.
[48] For convenience, using the patent language, the Court states below the common elements of claims 1 and 2 of the ‘670 patent, as they stood before the filing of the disclaimers:
(a) ring and tip connector means for connecting to telephone line ring and tip contacts and providing ring and tip signal outputs;
(b) a high impedance DC load and a gated line switch connected in series between said ring and tip signal outputs for controllably conducting an “off-hook” current between said ring and tip signal outputs;
(c) a transmit opto-coupler means having a transmit signal input and output;
(d) means for connecting said transmit signal output to said tip output and to a gate input of said gated