Buck v. Desvignes

489 F.2d 737
CourtCourt of Customs and Patent Appeals
DecidedDecember 27, 1973
DocketPatent Appeal No. 9016
StatusPublished
Cited by6 cases

This text of 489 F.2d 737 (Buck v. Desvignes) is published on Counsel Stack Legal Research, covering Court of Customs and Patent Appeals primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Buck v. Desvignes, 489 F.2d 737 (ccpa 1973).

Opinions

RICH, Judge.

This appeal is from the decision of the Board of Patent Interferences awarding priority to Desvignes. The sole issue is Desvignes’ right to make count 2. We affirm.

Buck et al. (Buck) filed no preliminary statement and are limited to the filing date of December 29, 1966, of Patent No. 3,403,284. Desvignes copied the count from the Buck patent into an application to reissue patent No. 3,322,955 which was awarded a convention date of December 24, 1959. The question is whether Desvignes' disclosure supports the count. On Buck’s motion to dissolve on the ground Desvignes had no right to make the count, the Primary Examiner ruled against Buck and the Board of Patent Interferences affirmed, awarding priority to Desvignes.

The invention relates to an improved target structure in television camera tubes. The Buck patent issued to Bell Telephone Laboratories, Inc., and the Desvignes patent to North American Philips Company, Inc. The count reads as follows:

2. In combination;

a target structure comprising a semi-conductive wafer, the wafer including adjacent one surface thereof an array of discrete rectifying barriers surrounded by regions free of rectifying barriers;

insulating means coating said surface selectively at portions overlying regions free of rectifying barriers and leaving exposed portions overlying the rectifying barriers;

means for forming and projecting an electron beam for scanning said one surface of the wafer;

and means for projecting an image to be recorded on the surface of the wafer opposite the one surface.

This count is directed to a combination of elements embodying an improvement in the type of electronic tube known as a “vidicon”1 which existed [738]*738prior to the invention of either party. In this tube, which functions as part of the TV camera system, a lens focuses the image to be transmitted on one surface of a small, thin wafer which exhibits local conductivity variations representative of the incident light intensity. The opposite surface of the wafer, which is placed in an electronic circuit, is scanned by an electron beam. As the beam scans, the instantaneous electron beam current generates the video signal. In the above count, the last two elements, namely, means for producing and controlling the electron beam and the optical means for projecting an image on the wafer, were old in the art and form no part of the subject matter invented by either party.

The language used to define the first element of the count — the target or wafer, which Desvignes also calls a plate or disc — has been the main subject of controversy in this interference and will require some discussion. The novel matter which is common to Buck and Des-vignes, however, relates to the second element of the count — the insulating means coating those portions of one surface of the wafer which are free of rectifying barriers and exposing those barriers to the scanning electron beam.

The count describes the first element as a wafer which has “adjacent one surface” an array of discrete rectifying barriers. We are here dealing with matter on a microscopic scale. Appellants’ brief tells us that typical devices “have 300,0002 single-barrier diodes formed into an area one-half inch square.” Their patent explains that these diodes are produced by forming in a wafer of semiconductor material having n-type conductivity isolated p-type regions of about 8 microns in diameter (0.008 mm) with eenter-to-center spacing of about 20 microns in both the length and width directions. With these discrete p-type regions formed into the surface of the n-type substrate, the p-type regions are, of course, surrounded by the original n-type material. It is not desired to have the electron beam strike the latter as it scans the surface and so the n-type material is covered, on that surface, by the insulating means which is the second element of the count.

The Buck patent shows that this diode array structure per se was not Buck’s invention but the invention disclosed in a prior patent of Reynolds, No. 3,011,089, issued Nov. 28, 1961, also assigned to Bell Telephone Laboratories, Inc. The Buck patent relates to improvements thereon, including the insulating layer of the count. The general description of this feature reads:

According to another feature, the p-type regions are insulated from each other and the n-type substrate is shielded from the beam by an insulating coating that exposes only the p-type regions to the beam. This feature prevents electron beam generation of spurious current in the output circuit which would otherwise result from bombardment of the substrate.

Desvignes, instead of forming diodes in a wafer of semiconductor material, in effect produces transistors, which have three elements rather than two. He doubly diffuses the surface of a wafer, 25 mms. in diameter and 0.15 mm. thick, having n-type conductivity through openings in an insulating grid of silicon oxide formed on the surface by photoetching techniques. The diffusion is by a technique used in the manufacture of transistors and produces, through the insulating grid, n-type conductivity on the surface beneath which is a layer of p-type conductivity. He thus gets, instead of diodes, a mosaic of N-P-N junctions which are scanned by the electron beam. Desvignes says they operate as phototransistors. Like Buck, and for the same reason, he does not want the electron beam to strike the n-type substrate material of the wafer which appears at the surface of the wafer surrounding the elements of the [739]*739mosaic and his insulating grid serves to prevent that. Relevant here is his disclosure of the insulating grid, which reads:

The silicon-oxide pattern on the front side of the plate [wafer] has restricted the diffusion of boron and arsenic [the diffusing materials giving the p- and n-type conductivity] to small, separate squares, which exhibit a checkerboard pattern. By maintaining this silicon-oxide grid, I have prevented the initial disc material, which has n-type conductivity, from directly receiving electrons of the scanning beam.

There has been no dispute about Desvignes’ support for the insulating grid element of the count. Buck’s argument has been centered on the fact that Buck discloses diode (P-N) regions formed into one surface of the wafer while Desvignes discloses N-P-N transistor type formations, similarly formed. With the aid of drawings of a schematic nature, Buck has zeroed in on the word “adjacent” in the first element- of the count and some of the language associated therewith, attempting to persuade us that the count is limited to a diode structure, which he discloses and Desvignes does not.

The board fully considered these arguments, giving its answer as follows:

As we read the count [,] giving the language the broadest interpretation which it reasonably will support, nothing is found in the count that would require a strict interpretation of “adjacent,” or require reading “adjacent” in a limited sense as urged by Buck et al. In our opinion, the requirement, “ . . .an array of discrete recti- - fying barriers surrounded by regions free of rectifying barriers;” is satisfied by the Desvignes structure which unquestionably has barrier-free regions between the areas E which completely encircle or encompass the areas E and hence surround those areas.

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489 F.2d 737, Counsel Stack Legal Research, https://law.counselstack.com/opinion/buck-v-desvignes-ccpa-1973.