Appeal from the District Court of the United States for the District of Delaware; John P. Nields, Judge.
Before BUFFINGTON, WOOLLEY, and THOMPSON, Circuit Judges.
BUFFINGTON, Circuit Judge.
In the court below John M. Miller, to whom Patent No. 1,756,000, for a piezo-electric oscillation generator, was granted April 22, 1930, charged, in two suits, the National Broadcasting Company, Inc., and R.C.A. Communications, Inc., with infringement thereof. The suits were heard together and disposed of by the court below in an opinion reported in (D.C.) 6 F. Supp. 47, 49. It was followed by decrees holding Miller's patent invalid for lack of invention. Appeals therefrom were taken and heard together in this court. The opinion of the trial judge is so thorough and exhaustive of all that can be said on the subject that a court affirming that court's decree can add little, if indeed anything, in the way of opinion without repeating what has been already sufficiently said. We therefore confine our opinion to a narrow compass.
Generally speaking, the case relates to circuits utilizing a piezoelectric crystal or quartz to control oscillation frequencies generated with the aid of a vacuum tube with associated circuits including a tuned plate one. As this quartz or crystal is the basic factor here involved, we note that it has two qualities, to wit, when compressed it develops an electric charge on some of its surfaces and, on the other hand, when it is charged by an electric current, the crystal is itself compressed and expanded. Its use in radio transmission, so far as we are here concerned, largely centers in the work of three men -- Professor Cady, the earliest worker, Professor Pierce, the second worker, and Dr. Miller, the plaintiff patentee, the third worker; so that this case, which concerns the use of such crystals in radio transmission, virtually narrows to the question whether in view of the earlier work of Cady and Pierce, of which Miller was informed, the patent of Miller in suit involved invention. The court below, with the witnesses before it, had better opportunity than have we of judging their credibility and the probabilities of their several accounts, and, so informed, held Miller's patent invalid, and our province is to determine whether the trial court, in so holding, committed error.
In taking up that question, we here note several important facts and the dates thereof. Referring to Professor Cady, it appears disclosures of his work were made first in a paper published in April, 1922, in the Proceedings of the Institute of Radio Engineers entitled "The Piezo-Electric Resonator." In his paper he disclosed to the art that a crystal was suitable to control the frequency of a vacuum tube oscillator; that a crystal was a sharply tuned element; that a crystal, like an electrically tuned circuit, had both capacitative and inductive reactance. He treated the crystal as though it were an electric circuit having resistance, capacity, and inductance. He followed this in the same month by an article in the Physical Review entitled "A Piezo-Electric Method for Generating Electric Oscillations of Constant Frequency," wherein he showed the use of a tunable plate circuit to increase the power tube of such oscillators. On May 28, 1921, Cady applied for patent No. 1,472,583 for method of maintaining electric currents of constant frequency, which was granted to him on October 30, 1923.
Referring next to Professor Pierce. He filed an application for a patent on February 25, 1924, for improvement in electrical systems. His work, to which he was attracted by Cady's earlier work, for the first half of 1923, was disclosed in a paper drafted in July and published in October, 1923, in "The Proceedings of The American Academy of Arts and Sciences," in which he described an oscillator, crystal controlled, in which the crystal was connected between the grid and the plate of the vacuum tube and in which an inductance coil was connected in the plate circuit.
The proofs show that these two men frankly and fully collaborated with each other and were, and are, in entire accord with each other as to what each man did in the advance of the use of quartz, that they recognized the fact and scope of the work of each other, and were of one mind as to the patent protection to which each was entitled. It is the use of their inventions by defendants which Dr. Miller claims are infringements.
On September 10, 1925, Dr. Miller applied for, and on April 22, 1930, was granted, patent in suit No. 1,756,000, for piezo-electric oscillation generator. The several works of these men, their relations to each other, the disclosures made, the acts of Dr. Miller, are all fully and fairly discussed by Judge Nields in his opinion and the reasons are therein set forth for his conclusions and why he was influenced by Cady and Pierce's testimony and was not influenced by Miller's.
Turning back to Cady's work and its relation to the radio art, it appears that he was largely instrumental in using quartz therein as a stabilizer of oscillation generated with the aid of vacuum tubes. Following the use of vacuum tube oscillation, the art was for the time being satisfied with the oscillation effected therein, but as it advanced and radio transmitters increased, the need arose that the frequency of oscillation be held more constant. It was to this problem that Professor Cady turned his attention and to the possibility of the use of quartz as answering that need. For years before this the electrical qualities of crystallines, such as quartz, were well known, and, when properly treated, their capacities, as electrical generators, so to speak, and their response when subjected to electric charges, was recognized. But no use was made in the radio art of these crystallines or of their electric functions or practical possibilities. Such use of quartz Cady essayed as early as 1917, and we think his subsequent work and its results are fairly summed up by defendant's counsel as follows: "* * * Cady * * * discovered that slabs of these piezo-electric crystals, when properly cut, had extremely sharp resonance characteristics at radio frequencies and that, when used in suitable circuits, they could be made to control the frequency of oscillations generated by vacuum tube oscillations generated by vacuum tube oscillators. He further found that an oscillator, so controlled, was extremely stable as to frequency -- in fact was far more stable than an oscillator whose frequency was controlled by an ordinary electrically tuned circuit composed, for example, of an inductance coil and condenser. He also found that quartz crystals were particularly adapted for this purpose."
In April, 1922, Cady, as we have seen above, disclosed these facts in a paper published in the Proceedings of the Institute of Radio Engineers, wherein he described circuits embodying his discovery. He also regarded the quartz as having the property of an electric tuned circuit. About the same time his paper on the same subject was published in the Physical Review (p. 139).
Cady's work and publications attracted the attention of Professor Pierce, and in 1923, led thereby, he began experiments and reached developments set forth, as we have seen, in a paper published in October, 1923, in the Proceedings of the American Academy of Arts and Sciences.
In estimating Cady's work, the trial judge held, and we agree with his finding, that Cady is recognized as the pioneer in the use of piezoelectric crystals and that in his paper "he disclosed to the art that a crystal was suitable to control the frequency of a vacuum tube oscillator; that a crystal was a sharply tuned element; that a crystal, like an electrically tuned circuit, had both capacitative and inductive ...