Zenith Radio Corp. v. Lehman

• Decision Date: 03 May 1954
• Parties: ZENITH RADIO CORP. v. LEHMAN.
• Court: U.S. District Court — Southern District of New York

121 F. Supp. 69

ZENITH RADIO CORP. v. LEHMAN.

United States District Court, S. D. New York.

May 3, 1954.

Paul Kolisch, New York City, Francis W. Crotty, Chicago, Ill., for plaintiff.

Victor D. Borst, Alan W. Borst, New York City, for defendant.

WEINFELD, District Judge.

Plaintiff Zenith Radio Corporation in this action seeks a declaratory judgment that three¹ models of hearing aids manufactured by it do not infringe Letters Patent No. 2,252,641, issued August 12th, 1941, and now owned by the defendant Charles H. Lehman, as assignee of the patent. Alternatively a judgment of invalidity of the patent is sought. The defendant has counterclaimed, charging infringement and seeks an accounting for damages.

The plaintiff moves for summary judgment on the issue of non-infringement pursuant to Rule 56 of the Federal Rules of Civil Procedure, 28 U.S.C.A., on the grounds that there is no genuine issue as to any material fact in respect to infringement, that as a matter of law there is no infringement, and that in view of the proceedings had in the United States Patent Office the defendant is estopped to assert such a scope of the claims as to include the accused apparatus.

Defendant's patent covers a combination.² It "relates to a method of transmitting speech and other sounds * * * within a limited space such as the auditorium of a cinema or theatre * * *." It is intended to assist people who are hard of hearing by providing means within a prescribed limited space in the theatre for actuating a small portable instrument used as a hearing aid. The system operates on the principle of induction. A conductor carrying an audio frequency current establishes an induction field which will induce energy in a pick-up coil positioned within that field. To carry the method into practice the patent employs a transmitting apparatus and a receiving apparatus: the transmitting apparatus to produce an induction field within a limited space; the receiving apparatus to be inductively energized by that field and to translate the energy thus picked up into audio intelligence. The method of energizing the receiver may vary. The receiver may be coupled to the induction field of the transmitting apparatus by means of a pick-up coil or may be used as a conventional hearing device when a microphone controlled by a switch is put into position.

Zenith's hearing aid, the accused device, consists only of a receiving apparatus. It involves no transmitting unit or system. It operates much like any other known vacuum tube amplifier hearing aid with a microphone to reproduce audio signals in the earphone worn by the hearing aid user. But it is also equipped with an induction coil or a "telephone coil" and a two-position switch. When the switch is in the position of "Mike" the telephone coil is not connected and the instrument operates in the usual manner of an ordinary vacuum tube hearing aid device. Switched to the alternate position of "Tel" the telephone coil is connected to the input circuit of the hearing aid amplifier and permits the use of the instrument for telephone conversations. This is accomplished by placing the telephone transmitter in close proximity to the telephone coil of the hearing aid. As a result, the induction field present at the receiver of the telephone instrument energizes the telephone coil of the hearing aid, establishing an inductive coupling by which the received phone conversation is transmitted through the induction field, the telephone coil, and the amplifier of the hearing aid to its earphone. And it is this telephone pick-up coil of plaintiff's instrument which is at the core of the present controversy.

Plaintiff's device is accused on the basis of claims 9, 19, and 20 — each one of which refers to either "base" claim 7 or 18. The defendant contends that the various receiving units with their pickup coils, as described in claims 9, 19, and 20 stand alone as self-sufficient "sub-combinations"³ and that Zenith's hearing aid with its pick-up coil infringes thereon. Zenith, contrariwise, argues that those claims are "dependent" claims which incorporate both the transmitting apparatus and the receiving apparatus described in base claims 7 and 18 to which they refer. Thus, the determination of the controversy turns upon the legal effect of claims 9, 19, and 20 and the parties acknowledge that the issue of law so presented makes the matter ripe for consideration of summary judgment.⁴ They agree that if the claims are read as "dependent" claims the plaintiff is entitled to summary judgment of non-infringement since it is admitted that Zenith's hearing aid does not infringe on base claims 7 and 18 — the entire combination.⁵ The parties are also in accord that if the claims are construed as "sub-combinations," as contended for by the defendant, the motion for summary judgment must be denied since testimony would be required on the question of infringement and, if reached, of validity.⁶

Zenith predicates its contention that claim 19 is a "dependent" claim on claim 19's reference to claim 18, the "base" claim. Claim 18 calls for an "apparatus for transmitting speech" and a "portable receiver." Claim 19 refers to "A receiving apparatus as claimed in claim 18 wherein the pick-up coil is adapted to be switched on to replace the microphone of a microphonic speech amplifying apparatus." Zenith maintains that the receiving unit does not stand alone but must be read in conjunction with the whole of claim 18 and in limitation thereof. The defendant, however, emphasizes that claim 19 by its language does not claim the combination of transmitting and receiving apparatus, as specified in claim 18, but "depends from" only that part of claim 18 which defines a portable receiver — a portable receiving apparatus which normally serves as a deaf aid appliance and includes a microphone, a pick-up coil which can be used to replace the microphone, and a sound reproducing device. Accordingly, it urges that the portable receiver defined in claim 19 is a complete and independent entity, a sub-combination. Similarly, claim 20 refers to claim 18, claim 9 makes reference to claim 7, and Zenith and defendant make the same arguments.

At the threshhold it is noted the defendant concedes, as it must, that the form of claim here in issue is without precedent and has never been judicially sanctioned. Neither does the defendant dispute plaintiff's contention that the Courts and Patent Office have never construed "dependent" claims to include less than the entire combination of elements recited in the base claim.

Out of context, claims 9, 19, and 20 would appear to make reference to but the receiving units of the base claims. But terms of patents do not stand by themselves; as in any contract, they must be read in context and with reference to the intent of the parties.⁷ The opening statement of the patent, the specifications, and the system described in the base claims make interpretation of the claims in question much more difficult than would appear at first blush.⁸ The patent is entitled "Method of and Apparatus for the Transmission of Speech or other sounds." The specification begins:

"The invention relates to a method of transmitting speech and other sounds, including recorded speech and sounds, within a limited space such as the auditorium of a cinema or theatre, or a sports arena; and to transmitting apparatus and receiving apparatus for carrying the method into practice. * * *"

The specification goes on to detail the system — its components and the best location of the units in the system. The "base" claims 7 and 18 read:

"An apparatus for transmitting speech and other sounds throughout a limited space by electromagnetic induction, comprising a thermionic amplifier, a looped conductor that extends within the area over which transmission is to take place and consists of a plurality of loops with certain loops arranged so that the flow of current therein is in a clockwise direction and the other loops arranged so that the flow of current therein is in a counter-clockwise direction, and a portable receiving device compromising a thermionic amplifier, a pick-up coil arranged in a low frequency input stage of said thermionic amplifier, and a sound reproducing device."

Furthermore, the usual practice of the Patent Office runs counter to what is urged here by the defendant. The Patent Office has never explicitly approved the practice of having a claim refer to but part of another claim. The usual "dependent" claim is of comparatively recent vintage and has had limited sanction. It is of British origin and was first allowed in 1917 by the Commissioner of Patents for the United States Patent Office in Ex parte Brown, 1917, C.D. 22, 235 O.G. 1355. Subsequent decisions restricted an applicant from building one dependent claim upon another; each dependent claim had to refer to a base claim.⁹ And in all instances since its inception the dependent claim has been construed to embody all the elements of the parent claim to which it refers and has been deemed a limitation grafted on the parent or "base" claim. These rulings are, in fact, now codified in Rule 75(c) of the Rules of Practice of the Patent Office.¹⁰ Thus, a fair assumption in light of the existing and then existing practice is that, had the claims been presented as other than conventional dependent claims, they would have been rejected much as were similar claims in Ex parte Hansen, 99 U.S. P.Q. 319.¹¹ In view of this, of the novelty of their form, and of the context in which they are to be read, claims 9, 19, and 20 are not unambiguous; the intent of the parties is far from clear.

Under the circumstances, reference to the file wrapper may be had to give the claims "the meaning which was intended by the applicant and understood by the examiner."¹² However, in so doing, I am mindful of the rule in this Circuit that "in the consideration of a file wrapper we do not look at the arguments...