The opinion of the court was delivered by: GALSTON
Infringement is alleged of letters patent No. 1,958,031 to E. L. Bresson, issued May 8, 1934, for a radio receiving system. The usual issues of invalidity and noninfringement are raised by the answer. Claims 3, 5, 6, 7, 9, and 10 are in issue.
The subject matter is one of considerable interest, relating as it does to a receiving set designed to receive signals from broadcasting stations over both longwave and short-wave bands.
The drawing and specification disclose an antenna which has connected to it a plurality of inductances, illustrated at 10' and 101 of the diagramatic drawing. The energy picked up by signal is transferred selectively from these inductances in parallel paths through oscillating circuits. These circuits are adapted to amplify and to rectify by means of oscillating circuits connected in cascade with the inductances. The oscillating circuits are so designed that the inductance 10' will respond to a band of carrier long-wave frequencies of standard broadcasting signals; and the inductance 101 to transfer selectively the energy of the band of so-called shortwave frequencies. Following the radio frequency stages of the circuits there are the usual stages of audio frequency. These are so connected as to be common to the two paths of amplification so that a single translating device, as a loudspeaker, may be employed. There is also provided a switch for connecting the translator and the source of power to either the short-wave amplifying and detecting means or to the long-wave amplifying and detecting means, and for disconnecting the translator and source from one or the other of said means.
Claim 10 of the patent may be regarded as typical. It reads: "In a device for receiving long or short radio waves, the combination comprising an antenna, shortwave amplifying and detecting means, longwave amplifying and detecting means, a source of power, a translator and a switch for connecting said translator and said source to said first-mentioned means and for disconnecting said translator and said source from said last-mentioned means and vice versa."
It may be observed that means for receiving long or short radio waves through the medium of an antenna and providing for amplification and detection with a source of power and loud speaker was old in the radio art. If then there is any novelty, it must be that which results from the particular combination set forth.
Some question arose at the trial as to the meaning of the terms "long" or "short" radio waves as used in the specification. The defendant urges that the terms are relative and that they cannot be defined without a standard of comparison. On the other hand, the plaintiff contends that "long wave" and "short wave" have accepted connotations in the art; that long waves embrace a band from 200 to 550 meters and short waves a band of 15 to 50 meters.
I think it only fair to conclude that Bresson, in his specification, was sufficiently clear, for he refers only to "long wave range of present day broadcasting stations and also throughout the range of the relatively short wave lengths of existing short wave broadcasting stations." To endeavor to give a different meaning to these terms as employed in the claims would not be justified.
Other terms in the claims require no particular interpretation, since they are all well understood in the art, though it may be observed that the switch referred to in the claims is not described or limited except by reference to its function.
The disclosure of the Bresson patent is of two separate parallel paths of tuning and of radio frequency amplifying and detecting of the signals received, followed by a common audio amplifying path and translator. With one path not in use, battery energy that would otherwise be used in lighting the idle tubes is conserved.
On July 25, 1911, the Navy Department in a communication relating to wireless telegraph installations stated that the bureau desired to establish a standard calling wave length for ships of 600 meters, a standard calling wave length for shore stations of 1,000 meters, and to improve the sharpness of tuning of all wireless transmitting apparatus.
Directions were given for inductively coupled oscillation transformers for ships, and it was said: "In addition to the calling wave-length, as many sharply tuned waves for communicating as the apparatus will permit, with full value of condenser, should be arranged for by providing plug sockets on primary and secondary of oscillation transformers with plugs; connecting leads, or by some other suitable arrangement."
The directions propose to divide all ships into two general classes, "long-wave ships and short-wave ships." The latter class would include vessels suited for communicating wave lengths from 300 to 500 meters, and vessels which use the wave lengths above 600 meters would be in the former class, and were to be designated "long-wave ships."
Shore stations were also directed to be equipped with inductively coupled oscillation transformers. Wireless stations were to be furnished with two receivers, of which one was to be type I -- P -- 76 receiver. Connection for the receivers was shown in the diagram transmitted with the letter of July 25, 1911, received in evidence as Exhibit JJ.These receivers were used with a listening-in key and telephone cords, so that one ear of the operator "may listen on one telephone for calls on one receiver and the other ear on the other telephone for calls on the other receiver, the key providing for connecting both telephones to one receiver."
One of the receivers was to be adjusted for receiving a 1,000 meter wave from shore stations and the other for receiving a 600 meter wave from ships. A variable condenser was employed with the short-wave receiver. The witness Clark testified that this form of duplex receiver was frequently used by the Navy during that early period.
There was no battery connected with the circuit as illustrated in the sketch, Defendant's Exhibit JJ. The device known as the I -- P -- 76 receiver, 1912-1913 type, is a two-receiver set, one adapted for short and the other for long wave reception, and a listening-in key with telephone leads. The diagrams and descriptions of this receiving system show the two receivers tuned to different wave bands. Fig. 3 of this instruction book discloses a similarity to the defendant's receivers, in that the position of the ...