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Publication numberUS3492523 A
Publication typeGrant
Publication dateJan 27, 1970
Filing dateAug 11, 1967
Priority dateApr 20, 1960
Publication numberUS 3492523 A, US 3492523A, US-A-3492523, US3492523 A, US3492523A
InventorsDeradoorian Bagdasar, Smith Hayden M, Thompson Robert R
Original AssigneeBendix Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of making an image intensifier array and resultant article
US 3492523 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Jan. 27, 1970 SMITH ET AL 3,492,523

" METHOD OF MAKING 'AN IMAGE INTENSIFIER ARRAY AND RESULTANT ARTICLE Original Filed June 9, 1961 GUIDE PI'NS STACKS OF ETCHED SHEETS BAGDASAR DERADOORIAN I HAYDEN M. SMITH w BY ROBERT R. THOMPSON ATTORNEY United States Patent US. Cl. 313-105 9 Claims ABSTRACT OF THE DISCLOSURE This invention pertains to a method of manufacturing an image intensifier array and the resultant article. A plurality of thin glass sheets compounded with oxides of lead and bismuth, are perforated as by photoetching, the glass sheets are stacked so that the perforations become aligned to form individual channels, and the individual thin sheets are bonded together with sufiicient sheets being used to establish the desired length of the channel. The interior surfaces of the array channels are then hydrogen reduced by heating said sheets to an elevated temperature while flowing hydrogen through the passages to produce a secondary emissive resistive surface.

BACKGROUND AND SUMMARY OF THE DEVELOPMENT This is a continuation of our copending application Ser. N0. 405,020, filed October 14, 1964, which is a continuation of application Ser. No. 116,044, filed June 9, 1961, and entitled Image Intensifier Array, both now abandoned.

In the Goodrich and Wiley patent, an image intensifier or channel multiplier is disclosed wherein a tube or channel of relatively small diameter in the order of .001 inch is provided on the inside surface with a secondary emissive resistive material. A voltage differential is placed across the tube or channel to accelerate incoming electrons through the channel and also provide current in the resistive coating for supplying electrons that are used in the secondary emission. An array of many of these tubes may be placed together to form a large area electron multiplier. An image intensifier can be made by placing a photocathode at one end of the array for conventing light rays into corresponding electron emission, and providing a phosphor screen at the other end of the array to convert the multiplied electrons into visible radiation.

This invention provides a method for constructing an array of such multipliers disclosed in the Goodrich and Wiley patent. In this invention a plurality of thin glass sheets compounded with oxides of lead and bismuth, are perforated as by photoetching, the glass sheets are stacked so that the perforations become aligned to form individual channels, and then the individual thin sheets are bonded together with sufficient sheets being used to establish the desired length of the channel.

It is therefore an object of this invention to form an array of small diameter individual tubes or channels which have a secondary emissive resistive surface on the interior thereof, which comprises the steps of perforating a plurality of thin glass sheets which contain compounds to make the sheets conductive to a desired degree, and stracking and bonding a sutficient number of sheets together with the perforations aligned to form a plurality of individual small diameter channels. The interior surfaces of the array channels are then hydrogen reduced 3,492,523 Patented Jan. 27, 1970 or otherwise treated to provide the desired resistive characteristics.

It is a further object of this invention to provide in such method the step of photoetching to produce the perforations in the individual glass plates.

It is a further object to place near the end of the array, such as between the final two layers of glass sheets, a highly conductive perforated plate so that a voltage lead may be attached to the plate to provide a gate for electrons formed in and coming through individual channels.

These and other objects and advantages will become more apparent when a preferred embodiment of this invention is considered in connection with the drawings in which:

FIGURE 1 is a plan view of a single sheet having a plurality of holes formed therein;

FIGURE 2 is a view in perspective of a partially completed stack of individual glass plates which are perforated and cemented in accordance with this invention; and

FIGURE 3 is a perspective view of a completed array.

Shown in FIGURE 1 is a glass sheet or film 20 which is in the order of .005 inch in thickness and may be composed of a mixture of 32 percent lead oxide, 61.3 percent silicon dioxide, 6.2 percent of barium carbonate and .5 of 1 percent bismuth trioxide. A plurality of holes 22 are formed in the sheet with the holes being small in diameter, in the neighborhood of .001 inch, and closely spaced. The spacing between holes in this embodiment is .1 the diameter of a hole. Two guide slots 24, 26 are formed near diagonally opposite corners of the sheet to effect alignment of the sheets as later explained.

The holes or perforations 22 may be formed in sheet 20 by a process known as photoetching. In this process a coating which is sensitive to light is placed on sheet 20.

. A transparent or transulcent negative having a plurality of opaque areas corresponding to the size and placement of holes 22 desired in sheet 20, is placed over the light sensitive coating and is exposed to a light for a predetermined length of time. The negative is removed and coating is then developed in a solution which dissolves the areas not subjected to the light, which would be the areas under the opaque sections corresponding to holes 22. An etch is used on the surface of the coating, which now has holes through it corresponding to holes 22 in glass sheet 20, to etch holes in sheet 20. After the etching is complete, a dissolver for the coating is utilized to clean the coating from sheet 20. This process is well known in the art and specific material for the light sensi tive coating, developing solution and etch can be obtained by consulting Techniques for Ruling and Etching Precise Scales in Glass and their Reproduction by Photoetching with a New Light Sensitive Resist US. National Bureau of Standards, circular 565:1-36, p. 30 C, Superintendent of Documents 1955. Also, photosensitive glass may be used in which case the step of applying and removing the resist coating on the glass becomes unnecessary.

Next, the individual glass sheets 20, prepared as previously described with perforations or holes 22, are stacked so that guide slots 24, 26 are aligned, and the stack is placed over guide pins 28, 30, FIGURE 2, so that the slots 24, 26 register with the slide over pins 28 and 30. In this manner all of the perforations or holes 22 become aligned to form the desired channels or tubes. After each sheet is placed over guide pins 28 and 30, a cement such as Coming Glass Company Pyroceram number 89 or solder glass may be applied to the outer boundaries thereof, to cement together adjacent sheets 20 upon the application of heat sufiicient to fuse the cement or solder glass but not hot enough to melt the sheets 20. Of course, the sheets may be fastened together in other suitable ways. Near one or both ends of the array, one or more conductive sheets 32, may be placed between two of the glass sheets 20. Sheets 32 may be of a metallic material such as a thin aluminum film and may have the holes formed therein in a manner similar to the glass sheets 20. A voltage lead 34 may be connected to the conductive sheet and a voltage applied to provide a gate to prevent the flow of electrons. For example, if a high negative potential is applied to the conductive sheet 32, the flow of electrons will be inhibited.

After the stack or array is completed and the individual sheets are cemented to each other or to conductive sheets, the array is subjected to a reducing procedure. Such reduction can be done by heating the array to 325 to 500 degrees centigrade for 8 to 16 hours while flowing one liter per minute of pure hydrogen through the channels of the array. This will provide a resistive surface of the desired characteristics for a particular application of about 100 angstroms units thick.

A conductive coating 36 may be put on the sheet at each of the array with a conductive paint such asa gold or silver paint or by vapor depositing the gold or silver or other conductive material at a steep angle on the sheet ends so that the conductive coating will not form on more than a minimum of the tube or channel interiors.

When this is completed, leads 38, 40 are attached to the conductive coatings and a voltage source 42 is placed therebetween to provide the necessary accelerating field across each tube and provide current for secondary emission form the resistive surfaces on each tube or channel.

Although this invention has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

What is claimed is:

1. A method of making an image intensifier array comprising the steps of forming in a plurality of thin insulative glass sheets containing at least one of the elements lead and bismuth, a plurality of relatively small diameter holes which are spaced apart a distance which is only a fraction of said hole diameters, stacking a plurality of insulative sheets so that each of said insulative sheets is in direct contact with another insulative sheet, aligning the holes of each sheet with the holes in adjacent sheets thereby forming a plurality of tubular passages with the number of said sheets in stacked relation being sufliciently large so that the length to diameter ratio of said tubular passages is relatively large, bonding and sheets together, hydrogen reducing the tubular passages formed in said sheets by heating said sheets to an elevated temperature while flowing hydrogen through the passages to produce a secondary emissive resistive surface on the side of said tubular passages.

2. A method of making an image intensifier array comprising the steps of forming in a plurality of thin insulative sheets which are in the order of .550" in thickness a plu-' rality of relatively small diameter holes which are in the order of .001 in diameter and spaced apart a distance which is only a fraction of said hole diameters, stacking a plurality of insulative sheets so that each of said insulative sheets is in direct contact with another insulative sheet, aligning the holes of each sheet with the holes in adjacent sheets thereby forming a plurality of tubular passages, bonding said sheets together, hydrogen reducing the tubular passages formed in said sheets by heating said sheets to an elevated temperature while flowing hydrogen through the passages to produce a secondary emissive resistive surface, placing a conductive coating on the faces of the sheet at each end of the array, and establishing an accelerating field across each tubular passage and providing current for secondary emission from the surface of the tubular passages by applying a voltage between the conductive coatings.

3. A method of making an image intensifier array comprising the steps of forming in each of a plurality of thin insulative sheets a plurality of relatively small diameter holes which are spaced apart a distance which is only a fraction of said hole diameters, stacking a plurality of insulative sheets so that each of said insulative sheets is in direct contact with another insulative sheet, said sheets being formed of glass containing one of the elements lead or bismuth, aligning the holes of each sheet with the holes of adjacent sheets thereby forming a plurality of tubular passages with the number of said sheets in stacked relation being sufliciently large so that the length to diameter ratio of said tubular passages is relatively large, bonding said sheets together, hydrogen reducing the tubular passages formed in said sheets by heating said sheets to an elevated temperature while flowing hydrogen through the passages to produce a secondary emissive resistive surface, applying a conductive coating on the faces of the sheet at each end of the array, and establishiing an accelerating field across each tubular passage and providing current for secondry emission for the surface of the tubular passages by applying a voltage between the conductive coatings.

4. The method of claim 3 further including the step of forming guide slots in each of the sheets, and each of said stacking and aligning steps including the substep of aligning said slots of guide pins.

5. The method of claim 3 in which said bonding step is performed by applying a cementing medium to the outer boundaries of the sheets and fusing the cementing medium in place.

6. The method of claim 3 further including the steps of placing a conductive layer between two of the insulative sheets, connecting a voltage lead to the conductive layer, and applying a voltage to the voltage lead to gate the flow of electrons through said tubular passages.

7. The method of claim 1 wherein said elevated temperature is within the range of approximately 325 to 500 C.

8. The product fabricated from the method of claim 1.

9. The product fabricated from the method of claim 2.

References Cited UNITED STATES PATENTS 2,588,920 3/1952 Green. 2,597,562 5/1962 Blodgett.

2,777,084 1/1957 Laiferty.

2,806,958 9/1957 Zunick.

2,817,781 12/1957 Sheldon 3l3-l05XR 2,821,637 l/l958 Roberts etal.

3,062,926 11/1957 McGee 313 355 XR 3,128,408 4/1960 Goodrich etal.

ROBERT F. BURNETT, Primary Examiner R. L. MAY, Assistant Examiner US. 01. X.R.

UNITED S'IA'IES PATENT OFFICE CERTIFICATE OF CORRECTION mom No. 3,422,523 Dated anuary 27, 1 70 lnv( ntor(.-;) I lq yt le r l Iil Sm1'th, Robert R. Thompson, Bagdasar Deradoor'ian It is (:crt'Ifiml lhat error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE SPECIFICATION Column l line 50, conventing. should read -converting-.

Column l line 69, stracki ng. should read --stack1'ng--.

Column 2, line 64, the. should read -and-.

Column 3, line 23, --end-- should appear after .each.

Column 3, line 32, .form. should read "from".

IN THE CLAIMS Claim 1 column 3, l ine 52, and. should read --sa1d-.

aim-21) All, when Nov 1 0 (SEAL) Attest:

Admin Offioer vmmm E. saw

g oomissioner or Pam FORM P0-1050 [10-69) USCOMM-DC GOING-P09 w u s. oovnnncm nmmna OFFICE: an o-su-su

Patent Citations
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US2588920 *Jan 29, 1947Mar 11, 1952Gen ElectricMethod of applying a vitreous coating composition to a glass base and article resulting thereform
US2597562 *Mar 30, 1949May 20, 1952Gen ElectricElectrically conducting layer
US2777084 *Apr 12, 1952Jan 8, 1957Gen ElectricPlastic electrode structure for electron tubes
US2806958 *Jan 21, 1954Sep 17, 1957Gen ElectricRadiographic diaphragm and method of making the same
US2817781 *May 27, 1954Dec 24, 1957Emanuel Sheldon EdwardImage storage device
US2821637 *Nov 30, 1953Jan 28, 1958Westinghouse Electric CorpLight image reproduction devices
US3062926 *Mar 20, 1959Nov 6, 1962Ronci John JMagnet with vibratable armature
US3128408 *Apr 20, 1960Apr 7, 1964Bendix CorpElectron multiplier
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3693005 *Feb 16, 1971Sep 19, 1972Philips CorpSecondary-emissive electrode
US3853528 *Feb 8, 1971Dec 10, 1974Siemens AgSlot nozzle for isotope separation of gaseous compounds
US4096626 *Dec 27, 1976Jun 27, 1978International Business Machines CorporationMethod of making multi-layer photosensitive glass ceramic charge plate
US4153855 *Dec 16, 1977May 8, 1979The United States Of America As Represented By The Secretary Of The ArmyMethod of making a plate having a pattern of microchannels
US4576679 *Nov 5, 1984Mar 18, 1986Honeywell Inc.Method of fabricating a cold shield
Classifications
U.S. Classification313/105.00R, 216/48, 216/20, 216/97, 156/252, 313/105.0CM
International ClassificationH01J43/24, C03B37/027, C03B23/00, C03B37/025, C03B37/15, C03B37/02, C03B37/10, H01J29/02, H01J31/50, C03B23/203, H01J31/08, H01J43/00
Cooperative ClassificationH01J43/24, H01J43/243, H01J29/023, C03B37/025, C03B23/203, H01J31/506, C03B37/15, C03B37/027
European ClassificationH01J43/24, C03B23/203, C03B37/15, H01J29/02D, H01J31/50G, H01J43/24B, C03B37/027, C03B37/025