US2975387A - Grey metallic selenium photocells - Google Patents

Description

March 14, 1961 R. D. GEORGEN ETAL 2,975,387

GREY METALLIC SELENIUM PHOTOCELLS Filed Oct. 28, 1955 IN V EN TORJ' BY THOMAS E. (AA/DGIPEN United States Patent 2,975,387 GREY NIETALLIC SELENIUM PHOTOCELLS Filed Oct. 28, 1955, Ser. No. 543,418

8 Claims. (Cl. 338-17) This invention relates to the manufacture and assembly of grey metallic selenium photocells, and more particularly to a group of said cells arranged in a mosaic pattern. While it has heretofore been known to group individual selenium photocells into a mosaic pattern comprising a plurality of such cells, it has also been common practice in such situations to treat each cell individually and to have each cell insulated from adjoining cells. It has also been known to manufacture selenium rectifiers by making a number of rectifiers in a sheet or mosaic pattern and subsequently separating the individual selenium rectifiers one from another by cutting or otherwise separating them.

The present invention is concerned primarily with the production of a mosaic arrangement of selenium photocells comprising a plurality of individual areas, each of the areas being responsive to the application of light thereto. Such an arrangement of photocells has been found highly advantageous in reproducing a pattern of light and dark. In such use a picture or other pattern of light and dark areas is thrown on the surface of the group of photocells and in accordance with the amount and location of the light in the pattern the individual portions of the mosaic photocell will pass current or not thereby enabling signals to be transmitted in accordance with the light pattern.

The object of the invention is to simplify the construction as well as the means and mode of operation of grey metallic selenium photocells, whereby such photocells may not only be economically manufactured, but will be more efficient and satisfactory in use, adaptable to a wide variety of applications, and be unlikely to get out of repair.

A further object of the invention is to provide a photocell which may be easily combined with others in adjacent contacting relation so as to provide when so assembled a mosaic pattern or arrangement of photocells covering a relatively large area.

A further object of the invention is to provide a mosaic arrangement of selenium photocells in which there is no insulation or separation between the adjacent contacting photocells of the group.

A further object of the invention is to provide a mosaic pattern of individually effective selenium photocells in which the metallic selenium comprising the mosaic arrangement is homogeneous and constitutes a single sheet of the material.

A further object of the invention is to provide a mosaic pattern of selenium photocells in which there is a single common terminal and circuit forming one side of the circuit for all individually effective cells and an individual electrode or contact approximately centered in each of the individually effective areas of the mosaic pattern.

A further object of the invention is to provide a selenium photocell possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein mentioned.

With the above primary and other incidental objects in view as will more fully appear in the specification,

the invention intended to be protected by Letters Patent.

consists of the features of construction, the parts and 2,975,387 Patented Mar. 14, 1961 combinations thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings, or their equivalents.

Referring to the accompanying drawing, wherein is shown one but obviously not necessarily the only form of embodiment of the invention:

Fig. 1 is a sectional view taken on line 1-1 of Fig. 2, showing one form of an individual cell which may be used to provide a mosaic pattern or grouping of photocells;

Fig. 2 is a vertical sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a transverse sectional view taken on line 33 of Fig. 4 showing another form of individual selenium photocells embodying the same principles which may be advantageously arranged in a mosaic pattern;

Fig. 4 is a vertical sectional view taken on line 44 of Fig. 3;

Fig. 5 is a vertical sectional view taken on line 55 of Fig. 6 showing another form and manner of produc ing a mosaic pattern of individually effective selenium photocells; and

Fig. 6 is a horizontal sectional view of a mosaic arrangement of individually effective selenium photocells taken on line 66 of Fig. 5.

Like parts are indicated by similar characters of reference throughout the several views.

Referring to the drawings, in accordance with the illustrated form of the invention shown in Figs. 1 and 2, a selenium photocell comprises a solid block 10 of an appropriate selenium material, cast or otherwise molded to the configuration shown. As a part of the molding operation, or subsequent thereto, there is imbedded in the block 10 a pair of metal pins or electrodes 11 and 12 longitudinally disposed in the block and sep arated from one another by the material thereof. At their one ends, the electrodes 11 and 12 extend through and beyond the block 10 and such projecting ends, it will be understood, are connected in series relation in an electrical circuit. The electrical resistance, as will be further understood, of the block 10 varies with intensity of applied light so that a circuit may alternative- 1y be opened and closed between the electrodes 11 and 12, as greater and lesser amounts of light are cast upon the block 10.

In the case of the embodiment of Figs. 3 and 4, a block 13 is formed which is like the block 10 of the first embodiment but which has only a single electrode 14 therein, the latter of which is centrally disposed with respect to the margin of the block. Such margins are coated with a layer 15 of a metallic, for example silver, paint. The layer 15 is thus electrically conductive and so may serve as one terminal of the photocell while the electrode 14 serves as the other.

A mosaic arrangement of photocells may be achieved by bringing multiple cells as shown in Fig. 1 or 3 into side by side relation in a group. According to the further concept of a mosaic arrangement, however, the selenium block material is formed in a single piece thus providing for simplicity of construction and fabrication as well as obtaining a homogeneous state in the selenium material for more constant and consistent response as among the several photocells comprising the mosaic arrangement.

Thus, as shown in Figs. 5 and 6, the selenium material is molded or otherwise shaped to the form of a sheet, for example to the square flat formation illustrated. Electrodes 17 are imbedded in the sheet 16, arranged in parallel rows, with the electrodes of each row being spaced equi-distant from one another and with the electrodes of adjacent rows being spaced apart equi-distant from one another. At their one ends, the electrodes 17 terminate at what may be considered to be the upper or sensitive surface 18 of the sheet. At their other ends, the electrodes 17 project through and beyond the opposite or lower surface 19 of the sheet for the attachment of electrical wire conductors thereto. The sensitive surface 18 is formed with a spaced apart series of grooves 21 running in one direction in the surface 18 and with another series of spaced apart grooves 22 running in the opposite direction in the sensitive surface, the result being to form a checker board pattern in such surface. At the center of each geometric figure so defined, is an electrode 17. On each margin of the figure, in surrounding relation to the electrode, are portions of the grooves 21 and 22. Within each groove 21 and 22 is a coating or layer 23 of a metallic paint or like conductive material, as the material comprising the layer 15 of Figs. 3 and 4. The grooves 21 and 22 intersect one another so that the metallic coating 23 forms a continuous network over the surface 18 and serves as a common terminal for all of the photocells comprised in the mosaic arrangement, each photocell further having an individual terminal in the form of an electrode 17.

The selenium photocells as disclosed, it will be understood, may be used as light sensitive control valves which are capable of passing more than one milliampere of light current when energized by a light source. The photocells may be used in series with sensitive relays or in conjunction with various type electronic triggering circuits, and particularly in the form of its mosaic arrangement may be used as an integral part of a reproduction process or system according to which light is caused to pass through the writings or drawings to be reproduced and cast on to the mosaic bank of photocells. The pattern of light and dark thus thrown on the surface of the group of cells is transformed into electrical signals transmitted by wire from the electrodes 17. The pattern of light and dark thrown on the surface of the cells passes therethrough in accordance with the amount and location of the light so that the signals transmitted are in accordance with the light pattern.

Neither the indicated size nor configuration of the geometric figures in the mosaic arrangement illustrated are critical to the performance of the device, and may be changed as may be appropriate or desired.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described our invention, we claim:

I. A selenium photocell comprising a one-piece solid block of selenium material having opposed surfaces one of which is the light receiving surface, and separated electrical contacts forming a unitary part of said block, said electrical contacts comprising a metallic point applied to the light receiving surface in a geometric pattern and metal post means embedded in the block in spaced relation with portions of the pattern and projecting through and beyond the other one of said opposed surfaces.

2. A selenium photocell comprising a one-piece solid block of selenium material having opposed surfaces one of which is the light receiving surface, and separated electrical contacts forming a unitary part of said block. said electrical contacts comprising intersecting stripes of metallic paint on the upper surface of the block defining a mosaic pattern of multiple blocks, and an electrode embedded in the center of each block so defined, said electrode extending through the bottom thereof.

3. A unitary mosaic arrangement of a plurality of photocells, including a one-piece sheet of selenium material, an electrical conductor adhesively mounted on one exposed surface of said sheet and laid out to define a pattern of multiple contiguous geometric figures, and an electrode imbedded in said sheet in approximately the center of each of said geometric figures and projecting through the opposite exposed surface of the sheet.

4. A unitary mosaic arrangement of a plurality of photocells, including a one-piece sheet of selenium material, a groove formation in one surface of said sheet defining a pattern of contiguous geometric figures, each representing an individual photocell, an electrode imbedded in said sheet in approximately the center of each of said figures at right angles to said one surface, said electrodes serving as individual terminals for said photocells, and electrically conductive means in said groove formation serving as a common terminal for said photocells.

5. An arrangement according to claim 4, characterized in that said electrically conductive means is a metallic paint.

6. A unitary mosaic arrangement of a plurality of photocells, including a one-piece sheet of selenium material, a plurality of spaced apart electrodes imbedded in said material, and electrically conductive means arranged on one surface of said sheet to define a pattern of contiguous geometric figures representing individual photocells, said electrodes being located substantially in the center of respective figures and serving as individual terminals for said photocells while said electrically conductive means serves as a common terminal.

7. A selenium photocell mosaic, including unitary seleniurn means having in one surface thereof a pattern of contiguous geometrical figures, each representing an individual photocell, an electrode imbedded in said selenium means in approximately the center of each of said geometric figures at right angles to said one surface, said electrodes serving as individual terminals for said photocells, and electrically conductive means installed in said one surface in superposed corresponding relation to said pattern and serving as a common terminal for said photocells.

8. A selenium photocell comprising a block of selenium material having opposed surfaces one of which is the light receiving surface, and separated electrical contacts forming a unitary part of said block, said electrical contacts comprising conductive means applied to the light receiving surface in a geometric pattern and metal post means embedded in the block in spaced relation with portions of the pattern, said metal post means projecting through and beyond the other of said opposed surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 1,790,736 Wald Feb. 3, 1931 1,880,289 Sukumlyn Oct. 4, 1932 1,899,026 Fessenden Feb. 28, 1933 1,935,650 McCreary Nov. 21, 1933 1,936,514 Lengnick Nov. 21, 1933 2,480,113 Betzler Aug. 30, 1949 2,540,490 Rittner Feb. 6, 1951 2,609,429 Law Sept. 2, 1952 2,668,184 Taylor et a]. Feb. 2, 1954 2,678,401 Iaegcr May 11, 1954 2,711,464 Anderson et al. June 21, 1955 2,747,104 Jacobs May 22, 1956 2,789,193 Anderson Apr. 16, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,975,387 March 14 1961 Robert D. Georgen et alo Column 3, lin 67 for "point" read paint Signed iand sealed ihis 22nd day of January 1963,

(SEAL) muss:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents Patent N08 2,975,387

Robert De Georgen et all,

It is hereby certified t ent requiring correction and corrected belowe hat error appears in the above numbered patthat the-said Letters Patent should read as Column 3, line 67, for "point" read paint Signed iand sealed this 22nd day of January 19630 (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting @fficer Commissioner of Patents March 14 1961 Patent No. 2,975,387 March 14, 1961 Robert D. Georgen et 31.,

It is hereby certified that er ent requiring correction and that corrected below.

ror appears in the above numbered patthe said Letters Patent should read as Column 3, line 67, for "point" read paint Signed fland sealed this 22nd day of January 1963,

(SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents

Images