CA1053992A - Methods and structures for metalizing a cathode ray tube screen - Google Patents
Methods and structures for metalizing a cathode ray tube screenInfo
- Publication number
- CA1053992A CA1053992A CA212,528A CA212528A CA1053992A CA 1053992 A CA1053992 A CA 1053992A CA 212528 A CA212528 A CA 212528A CA 1053992 A CA1053992 A CA 1053992A
- Authority
- CA
- Canada
- Prior art keywords
- layer
- faceplate
- phosphor
- cathode ray
- ray tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
- H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
- H01J29/18—Luminescent screens
- H01J29/28—Luminescent screens with protective, conductive or reflective layers
Landscapes
- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
- Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
This disclosure depicts methods and structures for applying a very thin layer of electrically conductive, light-reflective metal such as aluminum to the phosphor screen of a cathode ray tube. More particularly, there is disclosed the application of such a metal layer by the transfer of a metal layer formed on a substrate directly to a phosphor layer on the inner surface of a cathode ray tube faceplate. The metal layer is adhered to the phosphor layer by an adhering step which may involve the use of a pressure-sensitive adhesive.
In one embodiment disclosed, the substrate is then stripped off; alternatively, the substrate may be removed by dissolution or volatilization. Remaining volatile substances are driven off in a baking operation. Other associated and alternative operations are depicted.
This disclosure depicts methods and structures for applying a very thin layer of electrically conductive, light-reflective metal such as aluminum to the phosphor screen of a cathode ray tube. More particularly, there is disclosed the application of such a metal layer by the transfer of a metal layer formed on a substrate directly to a phosphor layer on the inner surface of a cathode ray tube faceplate. The metal layer is adhered to the phosphor layer by an adhering step which may involve the use of a pressure-sensitive adhesive.
In one embodiment disclosed, the substrate is then stripped off; alternatively, the substrate may be removed by dissolution or volatilization. Remaining volatile substances are driven off in a baking operation. Other associated and alternative operations are depicted.
Description
.
SPECIFICATION
Background of -the Invention .. . .
This invention relates in genera]. to the fabrication of phosphor screens for ca-thode ray tubes, and more particula.rl.y to imp.roved methods and structures for appl.ying a metal layer on the phosphor screen of a television cathode ray tube of a type havi.ng an envelope which includes a separate faceplate section. The metal layer, typically aluminum, has the. following primary functions~ First, it serves as the high voltage accelerating a.node for the ca.thode ray tube and acts as an electrically conductive layer for preventing the build up of charge on the screen. ~econd, it reflects to the viewer light emitted rearwardly by the phosphor screen. Third, it.. acts as a phys.ical ba.rrier preventing negative ions from striking the phosphor screen.
It is standard pra.ctice in the fabrication of cathode ray tube screens to deposit a phosphor layer containing the phosphor material and a binder on the inner surface of the faceplate. Subsequently, a thin layer of aluminum is evaporated on the phosphor layer. Before the metal layer is deposited on the phosphor layer, an intermediate smoothing film is applied ; in order to improve the surface characteristics of the deposited aluminum la.yer.
The deposition of the-thin metal layer, due to the nature of the vacuum deposition process, involves mounting the faceplate on a va.cuum chamber, pumping the chamber down to a vacuum, heating a boa.t of aluminum and timing the evaporation to insure deposition of a metal layer having the appropriate thi~ness ~typically 1500 A). The metal layer is desirably thick enough to reflect light emitted by the phosphor screen and yet thi.n enough to be transpa.rent to the electron beam.
The described evaporation process, particularly w~en set up on a. ~i.gh volume assembly line, is undesirably expensive.
SPECIFICATION
Background of -the Invention .. . .
This invention relates in genera]. to the fabrication of phosphor screens for ca-thode ray tubes, and more particula.rl.y to imp.roved methods and structures for appl.ying a metal layer on the phosphor screen of a television cathode ray tube of a type havi.ng an envelope which includes a separate faceplate section. The metal layer, typically aluminum, has the. following primary functions~ First, it serves as the high voltage accelerating a.node for the ca.thode ray tube and acts as an electrically conductive layer for preventing the build up of charge on the screen. ~econd, it reflects to the viewer light emitted rearwardly by the phosphor screen. Third, it.. acts as a phys.ical ba.rrier preventing negative ions from striking the phosphor screen.
It is standard pra.ctice in the fabrication of cathode ray tube screens to deposit a phosphor layer containing the phosphor material and a binder on the inner surface of the faceplate. Subsequently, a thin layer of aluminum is evaporated on the phosphor layer. Before the metal layer is deposited on the phosphor layer, an intermediate smoothing film is applied ; in order to improve the surface characteristics of the deposited aluminum la.yer.
The deposition of the-thin metal layer, due to the nature of the vacuum deposition process, involves mounting the faceplate on a va.cuum chamber, pumping the chamber down to a vacuum, heating a boa.t of aluminum and timing the evaporation to insure deposition of a metal layer having the appropriate thi~ness ~typically 1500 A). The metal layer is desirably thick enough to reflect light emitted by the phosphor screen and yet thi.n enough to be transpa.rent to the electron beam.
The described evaporation process, particularly w~en set up on a. ~i.gh volume assembly line, is undesirably expensive.
-2 ~xior ~rt ~53~
This inventioll is dir~cted to an improve~d catho~
xay tube screen meta]izatioll process i~volving the transfer of a metal layer to the screen. It has been suggested in U. S.
patents No. 2,734,013; 3,389,030; and 3,649,269 that a phosphor layer may be Eormed on the faceplate of a cathode ray tube by a transfer process. These patents discuss transfer processes in which a self-supporting we~ or decal containiny a phosphor material and a binder is formed on a base and then subsequently transferred to a flat plate or cathode ray tube faceplate.
Metalization of the transferred screen is achieved by conventional evaporation techniques after formation of the screen. U.~. Patent No~ 2,734,013 suggests as an alternative, without elaboration, that the "...light-re~lecting layèr may be applied...during~
lS ~-abrication of the decalcomania..."
None of these teachings are useful in solving the problem to which the present invention is addressed or at least the following reasons. The present invention involves the metalization of color phosphor screens, the phosphor patterns on which are, in the most common application, formed by photochemical processes which employ each tube's shadow mask as the mask for the phosphor pattern. A phosphor screen with a pre-formed phosphor pattern is thus not useful. Further, none of these patents deal with the metalization of pre-ormed phosphor screens.
. The brief suggestion in the '013 patent that the light-reflective layer may be trans~erred along with the phosphor layer is neither substantiated nor useful in the context of the present invention. UOS.P. 2,73~,013 su~gests the feasibility of tran~erring a metal layer to a cathode ray tube faceplalte, which la~er is supported on a laminate comprisin~ a layer o~
p~vsphor in a binder and a second ~ilm layer serving as ~ s~ooth . ' -ola~
base for the metal layer. The present invention is addressed to the much more difficult and dissimilar problem of transferring a very thin and frayile, unsupported layer of metal, typically only 1500 A thick, to a preformed patterned phosphor screen without tea.ring of the layer and with satisfactory uniformity and yield.
Metalization by direct tra.nsfer techniques has been known to be successfully tried only on small articles, as dis-closed, e.g., in the article "Application of the Transfex Tape Technique in Electron Tubes", ADVANCES IN ELECTRO~ TUB~ TEC~IQUES , Proceedings of the 6th National Conference, ~eptember, 1962 Other Prior Art U. S. Patent No. 2,858,233 objects of the Invention ~ It is a general object of this invention to provide improved methods and structures for metalizing the phosphor screen of a cathode ray tube.
It is a less general object to provide methods for meta.lizing ca.thode ray tu~e screens whlch are vastly more simple and economical than the prior art vacuum metalization methods.
It is yet another object to provide such metalization methods and structures which yield a. meta.l layer having greater reflect~v~ty than prior art methods and structures, and thus -to provide metalization methods and structures which result in a greater luminous output from the processed cathode ra.y tube~
Brief Descrip_ion of the Drawings The features of the invention which are believed to be novel are set forth with particularity in the appended claims.
This inventioll is dir~cted to an improve~d catho~
xay tube screen meta]izatioll process i~volving the transfer of a metal layer to the screen. It has been suggested in U. S.
patents No. 2,734,013; 3,389,030; and 3,649,269 that a phosphor layer may be Eormed on the faceplate of a cathode ray tube by a transfer process. These patents discuss transfer processes in which a self-supporting we~ or decal containiny a phosphor material and a binder is formed on a base and then subsequently transferred to a flat plate or cathode ray tube faceplate.
Metalization of the transferred screen is achieved by conventional evaporation techniques after formation of the screen. U.~. Patent No~ 2,734,013 suggests as an alternative, without elaboration, that the "...light-re~lecting layèr may be applied...during~
lS ~-abrication of the decalcomania..."
None of these teachings are useful in solving the problem to which the present invention is addressed or at least the following reasons. The present invention involves the metalization of color phosphor screens, the phosphor patterns on which are, in the most common application, formed by photochemical processes which employ each tube's shadow mask as the mask for the phosphor pattern. A phosphor screen with a pre-formed phosphor pattern is thus not useful. Further, none of these patents deal with the metalization of pre-ormed phosphor screens.
. The brief suggestion in the '013 patent that the light-reflective layer may be trans~erred along with the phosphor layer is neither substantiated nor useful in the context of the present invention. UOS.P. 2,73~,013 su~gests the feasibility of tran~erring a metal layer to a cathode ray tube faceplalte, which la~er is supported on a laminate comprisin~ a layer o~
p~vsphor in a binder and a second ~ilm layer serving as ~ s~ooth . ' -ola~
base for the metal layer. The present invention is addressed to the much more difficult and dissimilar problem of transferring a very thin and frayile, unsupported layer of metal, typically only 1500 A thick, to a preformed patterned phosphor screen without tea.ring of the layer and with satisfactory uniformity and yield.
Metalization by direct tra.nsfer techniques has been known to be successfully tried only on small articles, as dis-closed, e.g., in the article "Application of the Transfex Tape Technique in Electron Tubes", ADVANCES IN ELECTRO~ TUB~ TEC~IQUES , Proceedings of the 6th National Conference, ~eptember, 1962 Other Prior Art U. S. Patent No. 2,858,233 objects of the Invention ~ It is a general object of this invention to provide improved methods and structures for metalizing the phosphor screen of a cathode ray tube.
It is a less general object to provide methods for meta.lizing ca.thode ray tu~e screens whlch are vastly more simple and economical than the prior art vacuum metalization methods.
It is yet another object to provide such metalization methods and structures which yield a. meta.l layer having greater reflect~v~ty than prior art methods and structures, and thus -to provide metalization methods and structures which result in a greater luminous output from the processed cathode ra.y tube~
Brief Descrip_ion of the Drawings The features of the invention which are believed to be novel are set forth with particularity in the appended claims.
3~ The invention, together with further obje-cts and advantages thereof, ma.y best be understood by reference to the following descripti.on taken in conjunction with the accompa.nying dr.awings and in which:
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E`igures 1-8 show, in highly schematic fashion, a method and structure for metali~ing a cathode ray tube screen in accordance with this invention, and Figures ~ depict an alternative method for imple-menting the principles of this invention.
Description of the Preferred Embodiments . . . .. _ .
This invention has general applicability to the metal-ization of phosphor screens of cathode ray tubes of the types having envelopes including a discrete faceplate or front panel~
~n accordance with -this invention, the phosphor screen o:E a cathode ray tube is metalized by a transfer process which involves :Eorming a layer of metal to be applied to the screen on a substrate and subsequently transferring the metal la.yer to the phosphor screen. In a preferred method of practicing the in vention, shown diagrammatically in Figures 1-8, the-substrate is adapted to be stripped from the tra.nsferred metal layer.
Before engaging a. discussion of the preferred screen metaliæation process, there will first be described a preferred method for forming a metalized web from which the metal layer is transferred. Figure 1 illustrates a substra.te 10. For reasons which will become clear as this description proceeds, the substrate 10 is preferably composed of a flexible and deformable ~aterial which may, for reasons stated below, be a thermoplastic material, such as a polyester, having a~thickness approximately .0005 inch, however, it is contemplated that substrates composed of other materiais such as polypropylene and shrinkable polyester may be used.
A release agent 12 is preferably employed to release from the substrate 10 layers subsequently deposited thereon.
The release agent must be compatible with the operatiorL and ~:~
manufacture of the involved cathode ray tube and must provide a smooth ba~e for successively deposited layers; it may be removable~ as by dissolution or volatilization.
~.
3~2 . ~ .
By wa~ of example, i.t has been found ~hat a 4 x 10 7 inch layer o~ evaporated sodium chlor:Lcle wor]cs very satisfactorily~
It is contcmpl.atcd that other materials such as potas~ium chloride, or other salts may also be emplo~ed. Sodium chloride has ~een used previously as a release agent i.n an experimental image tube manufacturing process wherein a layer thereof was deposited upon a.-Elat glass substrate, followed by evaporation of a layer . of a].uminum. The substrate was immersed in a solvent which dissolved the sodium chloride, permit-tin~ the aluminum layer to float free in the solvent. The aluminum layer was lifted from the solv_nt and deposited upon the faceplate of a pre-screened image tube.
. Figure 2 SllOWS the Figure 1 substrate 10 a.nd release agent 12, upon which is deposited a thin layer 14 of electrically conductive, light reflective material such as alumi.num. In success~ul reductions to practice of the present invention, a layer of aluminum approximately 1500 A thick was evaporated on ~he substrate 10 and release agent 12 in a conventiona.l vacuum deposition chamber.
~0 To cause the metal layer 14 to adhere to a phosphor layer on the inner surface o a cathode ray tube faceplate (to be aescribed in d~tail be.low), a thin layer of adhesive 16 is deposited upo~ the metal layer 14 and cured. In accordance with this e~bodiment of the invention, the adhesive is pre~exably a. pressure-sensitive adhesive su~h as K-396N or 86-2003, manu-~a~ture~ by National Starch & Chemical Corporation, which is capable of being converted to gaseous form if heated to tempera-tures above about 400~C. By way of example~ a 100-400 A layer o~ such adhesive may be employed as the adhesive 16.
The adhesive 16 preerably ~as a high flash point in the intere~t of saety; it a.lso must be compatible with cathode ray tub~ m~nufacture and ope.rationO It is desirably used i~ the ' ' ' ; ,.
.
smallest amount as possible which will cause satisfactory adhesion of the metal layer since lt will ul.timately have to be baked out through the transferred metal layer. In the pre-ferred method of application the adhesive .is sprayed upon the metal layer 14 so as to form a discontinuous layer comprising discrete adhesive drops spaced on the surface of the metal layer 14. It is contemplated that other adhesives than those described and other application methods may be employed to carxy out the teachings of this invention.
Figure 4 depicts a cathode ray tube faceplate 18 having disposed on an inner surface 20 thereof a phosphor layer ~.' 22 comprising a phosphor material held in a pho-tosensitized binder. The phosphor layer 22 may be deposited by conventional slurry techniques and comprises, ,in a color cathode ray tube, e.,g., successively-deposited layers of red-emissive, blue-emissive and green-emissive phosphor materials carried typically in a photosensitized binder of PVA (polyvinyl alcohol).
Figure 5 illustrates a step wherein the web 24, com-. pri'sing subs~rate 10, release agent 12, metal layer 14 and adhesive 16, is applied to the phosphor layer 22. In the schematic Figure 5 illustration, the application is accomplished by first draping the web 24 o,ver a mandril 26. In the Figure 5 illustration, the mandril 26 is shown as comprising a base 28 having an upper surface 30 having generally the contour of the -~ inner surface 20 of the faceplate 18. Disposed on ~he base 28 , ~-is a resilient cushion 32 which is somewhat thicker in the center ~ -than on the edges in order that the mandril will have a yiel,dable upper surface and in order that the mandril will cause the web 24 to engage the phosphor layer 22 initially in the center of the : 30 faceplate and thereaftar to cause the web to be pressed against .the phosphor layer 22 progressively outwardly from the :Eaceplate :
centerO By this technique, ~ormation o~ -.. . ..
. - 7 ~
053~9~
bubblcs under the ~eb is precluded. ~ simi.lar presCli.ng technique is disclosec~ in thc referent patent 3,389,030 in thc manufacture of black and white cathode ray tubes. Other mandril structures ~nd applica~ion techniques may be employed. It may be desir~hle, in order to effect a more rapid or more conforming applica~ion of the web 24 to the phosphor layer 22, to apply heat and/or air pressure to the web 2~ as it is applied to t.he mandril or to the phosphor layer 22.
After the web 24 is adhered to the phosphor layer 22, the mandril 26 is removed, leaving on the faceplate.a decal having the shape of the cathode ray tube screenO The invention is preferably employed for metalizing a phosphor screen of the "black surround" type describe~ and claimed in U. S. Patent No.
3,146,368.- Fiore et al. A phosphor screen formed according to this patent has black material separating phosphor elements which emit different colored light. The black materia1 typically extends beyond the electron-illuminated fieId and onto the sides of the faceplate. The decal preferably overlaps the black material in a screen of this t~pe, precluding any need to form the decal to the exact shape of the electron-illuminated field. The decal may be formed by pre-cutting an outline of the decal configuration with perforations befoxe transferring the decal, ~r, alternatively, the decal may be trimmed in situ. The shape of the metal layer deposited`on the substrate can be determined, if desired, by evaporating the metal layer onto ~le substrate through a mask having an opening corresponding in configuratlon to ~he screen configuration. Alternatively, a pre-cut decal, ra~her than a ~ontinuous web, hAving the configuration of the screen may be employed~ .
In order to minimize breaking of the metal layer during ~he web draping operation, it ma~ be desirable to pxe~:Eorm or partiall~ pre-form the substxatQ to the contour of the ma~dril ~B-i3~Z
or the f~ceplate be~ore ~eposition of th~ metal 3.ayer thereon.
So that the substrate may nevertheless be handled in roll form, ~ pre-contoured decals may be ~ormed at intervals on a substrate . roll~ the decal~ corresponding generally in size and configura~
tion to the screen and having concentric circular or rectangular flutes or corrugations defining a flat bellows whi.ch is expan~
sible out of the plane of the we~ without stretching thereof.
When the decals.are drawn over the mandri]., the bellows will open and permit the decal to assume the shape of the mandril without excessive stretching thereof.
As shown in Figure 6, the substrate 10 is then stripped away, leaving on the inner surface of the faceplate 18 the phosphor layer 22, the adhesive 16, the metal layar 14 and the release agent 12. . , - If the release agent is sodium chloride, or example, or some other composition which is capable of being dissolved, the release agent may be removed by a suitable solvent. See Figure 7. If sodium chloride is used, the solvent ma.y be water.
The solvent, of course, will vary with the release agent used. ~:
Alternatively, i ~he release agent is sodium chloride, it may : .
be desirable for reasons o~ economy to eliminate the release agent removal.operation altogether. Tests have shown that the presence of sodium chloride in the tube does not result, upon electron bombardment, in poisoning of the electron guns.
Figure 8 illustrates a baking operation for driving off the photosensitized binder from .the phosphor layex, the adhesive layer 16 and, where the release agent may ba of a . .
nature as to be readily volatilized, the release agent~ It i~
conventional in the manufaeture of cathode ray tubes to include a "bake-out" operation during which the photosensitized binder and the afore-described smoothing layer or "film" deposited to ~orm a base for tha avapo~ated aluminum layer, are driven , _9~
off. Thus, since a bake-out operation is required as a . necessary step in the conventional manufacture of a cathode ray tube, the removal of the adhesive 16 can be achieved without the necessity of a.dding any speci.al tube processing operations.
Thus, by the use of the above-described metal transfer web, : and by the above-described method, the phosphor screen of a.
. cathode ray tube may be rapidly and economi.cally me~alized.
It has been found in a number o~ screens built and tested, that beca.use the metal layer 14 is deposited upon a ` 10 smooth surface, iOe., the prepared upper surface of the substrate 10, rather than on a relatively rough surface as in the case I of conventiona.l metalization of phosphor screens, the resulting ¦ metal layer is smoother tha.n the metal layers deposited by I conventional evaporation techniques. Tests ha.ve shown tha.t in some ca.ses, gains in brightness of the end product cathode ray tubes have been achleved.
Figures 9~15 portray in highly schematic form a second embodiment of the invention wherein the substxate comprising the .
base for a transfer web or decal is not strippable, but rather is adapted to be removed by dissolution or volatilization.
As above, before enga.ging a. discussion of the Figures 9-15 screen metaliza.tion process, there will first be described a pr~ferred method for forming the metalized decal or web from which the metal layer is transferred. Figure 9 illustrates a substrate 40. For reasons which will become clear as this description proceeds, the substrate 40 is preferably composed of a. flexible plastic material which may, for reasons stated below, be dissolved or voIatilized. A suitable substrate material is an acrylic fi.lm having a thickness approximately .0005 to .0010 i~ch, however, i.t i5 contemplated that a substrate composed of other materials such as nitro-cellulose may be used.
--lû--5i3~
Figure lO shows the Figure 9 substra.te 42, upon which is deposited a thin layer 44 of electrically conductive, lic~ht-reflective material such as aluminum. rrO cause the metal layer 44 to adhere to a phosphor layer on the lnner surface of a cathode ray tube faceplate (to be described in detail below), a layer 46 of adhesive is deposited upon the metal layer 44 (see Figure lP) or on the inner surface 48 of the faceplate 50O
In accordance with this embodiment of the invention, the adhesive preferably takes the form of a thin film of ethyl silicate.
Figure ll depicts a cathode ray tube faceplate 50 having a novel flangeless configuration, on an inner surface 48 of which is disposed a phosphor layer 52 comprising a phosphor material held in a binder. The phosphor layex 52 may be as layer 22 descri.bed above. L
Figure 12 illustrates a step wherein a decal 54, com- :
prising substrate 42, meta.l layer 44 and a.dhesive layer 46, is applied to the phosphor layer 52. As discussed a.bove, the decal 54 is preferably formed to the shape and curvature of the inner surface 48 o~ the faceplate 50 to minimize wrinkling of the decal 54 upon transfer thereto and to minimize stretching of the metal layer ~4.
In the schematic Fiyure 12 illustration, the a.pplication is accomplished by first draping the deca.l 54 over a mandril 56 and securing it thereto. A tension band 57 is shown to sche-matically illustrate mea.ns for securing the deca.l 54. Themandril 56 and the decal application operation represented by Figure 1~ ma.y be as described above with respect to Figure 5.
After ~he decal 54 is adhered to the phosphor layer 52, the mandril 56 is removed, leaving on the faceplate 50 a decàl 54 having the shape of the cathode ray tube screen~
The substrate 42 is then removed, preferably in thi.s method embodiment by dissoluti.on, as shown schema.tically in ~53~'3~
Figure 14, leaving on the inner surface 48 of the faceplate 50 the phosphor layer 52, the adhesive layer 46 and the metal layer 44. If the substrate 42 comprises an acrylic, the solvent is preferably toluene. If the substrate 42 comprises nitro-cellulose, the solvent is preferably acetone and amyl acetate.
If the substrate 42 is of a composition such as acrylic which is readily volatilized rathex than dissolved, the dissolution step shown in E~igure 14 would, of course, be eliminated. Rather, the faceplate would be baked, as shown ~ schematically in Figure 15 to volatilize and drive off the i substrate.
~ he bakiny operation, represented in Figure 15 by an oven S8, may be the conventional "bake-out" operation during which the phosphor binder and the afore-described smookhing layer or "film" deposited to form a base for the evapora,ed aluminum layer, are driven off. Thus, since a bake-out opera-tion is required as a necessary step in the conventional manu-facture of a cathode ray tube, the removal of the substrate 12 and the adhesive layer 16 can be achieved without the necessity of adding any special tube processing operations.
The invention is not limited to the particular details of construction of the embodiments depicted and other modifi-cations and applications are -contemplated. Certain changes 25 may be made in the above-described methods and apparatus without departing from the true spirit and scope of the invention herein involved. For example, to minimize the possibility of blistering of the metal layer during the baXe-out operation, the metal layer deposited upon the substrate may be caused to have tiny per-forations whi~h will serve ultimately as out-gassing openings for the materials volatilized under the metal layer. In the Fig~res 1-8 embodiment, rather than using a release agent, as -12~
~ ~ ~53~
described, satisfactory results may be obtainable by the use of a non-stic]s substrate, the sur:Eace of whi.ch inherently has low adherance to the metal layer. Alternatively, other forces than adhesion, e.g., electrostatic, may be employed to hold the metal layer upon the strippable suhstrate until. the transfer of the metal layer is accomplished. Whereas in the above-described methods the binder in the phosphor layer -to which the metal layer is transferred is described a.s a photosensitized binder, the invention is e~ually applicable to transferring a metal layer onto phosphor layers ha.ving non-sensitized organic binders or phosphor layers of other compositions. It is intended, therefore, that the subject matter of the above depiction shall be interpreted as illustrative and not in a limiting sense.
. .
. ~ .
, .
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E`igures 1-8 show, in highly schematic fashion, a method and structure for metali~ing a cathode ray tube screen in accordance with this invention, and Figures ~ depict an alternative method for imple-menting the principles of this invention.
Description of the Preferred Embodiments . . . .. _ .
This invention has general applicability to the metal-ization of phosphor screens of cathode ray tubes of the types having envelopes including a discrete faceplate or front panel~
~n accordance with -this invention, the phosphor screen o:E a cathode ray tube is metalized by a transfer process which involves :Eorming a layer of metal to be applied to the screen on a substrate and subsequently transferring the metal la.yer to the phosphor screen. In a preferred method of practicing the in vention, shown diagrammatically in Figures 1-8, the-substrate is adapted to be stripped from the tra.nsferred metal layer.
Before engaging a. discussion of the preferred screen metaliæation process, there will first be described a preferred method for forming a metalized web from which the metal layer is transferred. Figure 1 illustrates a substra.te 10. For reasons which will become clear as this description proceeds, the substrate 10 is preferably composed of a flexible and deformable ~aterial which may, for reasons stated below, be a thermoplastic material, such as a polyester, having a~thickness approximately .0005 inch, however, it is contemplated that substrates composed of other materiais such as polypropylene and shrinkable polyester may be used.
A release agent 12 is preferably employed to release from the substrate 10 layers subsequently deposited thereon.
The release agent must be compatible with the operatiorL and ~:~
manufacture of the involved cathode ray tube and must provide a smooth ba~e for successively deposited layers; it may be removable~ as by dissolution or volatilization.
~.
3~2 . ~ .
By wa~ of example, i.t has been found ~hat a 4 x 10 7 inch layer o~ evaporated sodium chlor:Lcle wor]cs very satisfactorily~
It is contcmpl.atcd that other materials such as potas~ium chloride, or other salts may also be emplo~ed. Sodium chloride has ~een used previously as a release agent i.n an experimental image tube manufacturing process wherein a layer thereof was deposited upon a.-Elat glass substrate, followed by evaporation of a layer . of a].uminum. The substrate was immersed in a solvent which dissolved the sodium chloride, permit-tin~ the aluminum layer to float free in the solvent. The aluminum layer was lifted from the solv_nt and deposited upon the faceplate of a pre-screened image tube.
. Figure 2 SllOWS the Figure 1 substrate 10 a.nd release agent 12, upon which is deposited a thin layer 14 of electrically conductive, light reflective material such as alumi.num. In success~ul reductions to practice of the present invention, a layer of aluminum approximately 1500 A thick was evaporated on ~he substrate 10 and release agent 12 in a conventiona.l vacuum deposition chamber.
~0 To cause the metal layer 14 to adhere to a phosphor layer on the inner surface o a cathode ray tube faceplate (to be aescribed in d~tail be.low), a thin layer of adhesive 16 is deposited upo~ the metal layer 14 and cured. In accordance with this e~bodiment of the invention, the adhesive is pre~exably a. pressure-sensitive adhesive su~h as K-396N or 86-2003, manu-~a~ture~ by National Starch & Chemical Corporation, which is capable of being converted to gaseous form if heated to tempera-tures above about 400~C. By way of example~ a 100-400 A layer o~ such adhesive may be employed as the adhesive 16.
The adhesive 16 preerably ~as a high flash point in the intere~t of saety; it a.lso must be compatible with cathode ray tub~ m~nufacture and ope.rationO It is desirably used i~ the ' ' ' ; ,.
.
smallest amount as possible which will cause satisfactory adhesion of the metal layer since lt will ul.timately have to be baked out through the transferred metal layer. In the pre-ferred method of application the adhesive .is sprayed upon the metal layer 14 so as to form a discontinuous layer comprising discrete adhesive drops spaced on the surface of the metal layer 14. It is contemplated that other adhesives than those described and other application methods may be employed to carxy out the teachings of this invention.
Figure 4 depicts a cathode ray tube faceplate 18 having disposed on an inner surface 20 thereof a phosphor layer ~.' 22 comprising a phosphor material held in a pho-tosensitized binder. The phosphor layer 22 may be deposited by conventional slurry techniques and comprises, ,in a color cathode ray tube, e.,g., successively-deposited layers of red-emissive, blue-emissive and green-emissive phosphor materials carried typically in a photosensitized binder of PVA (polyvinyl alcohol).
Figure 5 illustrates a step wherein the web 24, com-. pri'sing subs~rate 10, release agent 12, metal layer 14 and adhesive 16, is applied to the phosphor layer 22. In the schematic Figure 5 illustration, the application is accomplished by first draping the web 24 o,ver a mandril 26. In the Figure 5 illustration, the mandril 26 is shown as comprising a base 28 having an upper surface 30 having generally the contour of the -~ inner surface 20 of the faceplate 18. Disposed on ~he base 28 , ~-is a resilient cushion 32 which is somewhat thicker in the center ~ -than on the edges in order that the mandril will have a yiel,dable upper surface and in order that the mandril will cause the web 24 to engage the phosphor layer 22 initially in the center of the : 30 faceplate and thereaftar to cause the web to be pressed against .the phosphor layer 22 progressively outwardly from the :Eaceplate :
centerO By this technique, ~ormation o~ -.. . ..
. - 7 ~
053~9~
bubblcs under the ~eb is precluded. ~ simi.lar presCli.ng technique is disclosec~ in thc referent patent 3,389,030 in thc manufacture of black and white cathode ray tubes. Other mandril structures ~nd applica~ion techniques may be employed. It may be desir~hle, in order to effect a more rapid or more conforming applica~ion of the web 24 to the phosphor layer 22, to apply heat and/or air pressure to the web 2~ as it is applied to t.he mandril or to the phosphor layer 22.
After the web 24 is adhered to the phosphor layer 22, the mandril 26 is removed, leaving on the faceplate.a decal having the shape of the cathode ray tube screenO The invention is preferably employed for metalizing a phosphor screen of the "black surround" type describe~ and claimed in U. S. Patent No.
3,146,368.- Fiore et al. A phosphor screen formed according to this patent has black material separating phosphor elements which emit different colored light. The black materia1 typically extends beyond the electron-illuminated fieId and onto the sides of the faceplate. The decal preferably overlaps the black material in a screen of this t~pe, precluding any need to form the decal to the exact shape of the electron-illuminated field. The decal may be formed by pre-cutting an outline of the decal configuration with perforations befoxe transferring the decal, ~r, alternatively, the decal may be trimmed in situ. The shape of the metal layer deposited`on the substrate can be determined, if desired, by evaporating the metal layer onto ~le substrate through a mask having an opening corresponding in configuratlon to ~he screen configuration. Alternatively, a pre-cut decal, ra~her than a ~ontinuous web, hAving the configuration of the screen may be employed~ .
In order to minimize breaking of the metal layer during ~he web draping operation, it ma~ be desirable to pxe~:Eorm or partiall~ pre-form the substxatQ to the contour of the ma~dril ~B-i3~Z
or the f~ceplate be~ore ~eposition of th~ metal 3.ayer thereon.
So that the substrate may nevertheless be handled in roll form, ~ pre-contoured decals may be ~ormed at intervals on a substrate . roll~ the decal~ corresponding generally in size and configura~
tion to the screen and having concentric circular or rectangular flutes or corrugations defining a flat bellows whi.ch is expan~
sible out of the plane of the we~ without stretching thereof.
When the decals.are drawn over the mandri]., the bellows will open and permit the decal to assume the shape of the mandril without excessive stretching thereof.
As shown in Figure 6, the substrate 10 is then stripped away, leaving on the inner surface of the faceplate 18 the phosphor layer 22, the adhesive 16, the metal layar 14 and the release agent 12. . , - If the release agent is sodium chloride, or example, or some other composition which is capable of being dissolved, the release agent may be removed by a suitable solvent. See Figure 7. If sodium chloride is used, the solvent ma.y be water.
The solvent, of course, will vary with the release agent used. ~:
Alternatively, i ~he release agent is sodium chloride, it may : .
be desirable for reasons o~ economy to eliminate the release agent removal.operation altogether. Tests have shown that the presence of sodium chloride in the tube does not result, upon electron bombardment, in poisoning of the electron guns.
Figure 8 illustrates a baking operation for driving off the photosensitized binder from .the phosphor layex, the adhesive layer 16 and, where the release agent may ba of a . .
nature as to be readily volatilized, the release agent~ It i~
conventional in the manufaeture of cathode ray tubes to include a "bake-out" operation during which the photosensitized binder and the afore-described smoothing layer or "film" deposited to ~orm a base for tha avapo~ated aluminum layer, are driven , _9~
off. Thus, since a bake-out operation is required as a . necessary step in the conventional manufacture of a cathode ray tube, the removal of the adhesive 16 can be achieved without the necessity of a.dding any speci.al tube processing operations.
Thus, by the use of the above-described metal transfer web, : and by the above-described method, the phosphor screen of a.
. cathode ray tube may be rapidly and economi.cally me~alized.
It has been found in a number o~ screens built and tested, that beca.use the metal layer 14 is deposited upon a ` 10 smooth surface, iOe., the prepared upper surface of the substrate 10, rather than on a relatively rough surface as in the case I of conventiona.l metalization of phosphor screens, the resulting ¦ metal layer is smoother tha.n the metal layers deposited by I conventional evaporation techniques. Tests ha.ve shown tha.t in some ca.ses, gains in brightness of the end product cathode ray tubes have been achleved.
Figures 9~15 portray in highly schematic form a second embodiment of the invention wherein the substxate comprising the .
base for a transfer web or decal is not strippable, but rather is adapted to be removed by dissolution or volatilization.
As above, before enga.ging a. discussion of the Figures 9-15 screen metaliza.tion process, there will first be described a pr~ferred method for forming the metalized decal or web from which the metal layer is transferred. Figure 9 illustrates a substrate 40. For reasons which will become clear as this description proceeds, the substrate 40 is preferably composed of a. flexible plastic material which may, for reasons stated below, be dissolved or voIatilized. A suitable substrate material is an acrylic fi.lm having a thickness approximately .0005 to .0010 i~ch, however, i.t i5 contemplated that a substrate composed of other materials such as nitro-cellulose may be used.
--lû--5i3~
Figure lO shows the Figure 9 substra.te 42, upon which is deposited a thin layer 44 of electrically conductive, lic~ht-reflective material such as aluminum. rrO cause the metal layer 44 to adhere to a phosphor layer on the lnner surface of a cathode ray tube faceplate (to be described in detail below), a layer 46 of adhesive is deposited upon the metal layer 44 (see Figure lP) or on the inner surface 48 of the faceplate 50O
In accordance with this embodiment of the invention, the adhesive preferably takes the form of a thin film of ethyl silicate.
Figure ll depicts a cathode ray tube faceplate 50 having a novel flangeless configuration, on an inner surface 48 of which is disposed a phosphor layer 52 comprising a phosphor material held in a binder. The phosphor layex 52 may be as layer 22 descri.bed above. L
Figure 12 illustrates a step wherein a decal 54, com- :
prising substrate 42, meta.l layer 44 and a.dhesive layer 46, is applied to the phosphor layer 52. As discussed a.bove, the decal 54 is preferably formed to the shape and curvature of the inner surface 48 o~ the faceplate 50 to minimize wrinkling of the decal 54 upon transfer thereto and to minimize stretching of the metal layer ~4.
In the schematic Fiyure 12 illustration, the a.pplication is accomplished by first draping the deca.l 54 over a mandril 56 and securing it thereto. A tension band 57 is shown to sche-matically illustrate mea.ns for securing the deca.l 54. Themandril 56 and the decal application operation represented by Figure 1~ ma.y be as described above with respect to Figure 5.
After ~he decal 54 is adhered to the phosphor layer 52, the mandril 56 is removed, leaving on the faceplate 50 a decàl 54 having the shape of the cathode ray tube screen~
The substrate 42 is then removed, preferably in thi.s method embodiment by dissoluti.on, as shown schema.tically in ~53~'3~
Figure 14, leaving on the inner surface 48 of the faceplate 50 the phosphor layer 52, the adhesive layer 46 and the metal layer 44. If the substrate 42 comprises an acrylic, the solvent is preferably toluene. If the substrate 42 comprises nitro-cellulose, the solvent is preferably acetone and amyl acetate.
If the substrate 42 is of a composition such as acrylic which is readily volatilized rathex than dissolved, the dissolution step shown in E~igure 14 would, of course, be eliminated. Rather, the faceplate would be baked, as shown ~ schematically in Figure 15 to volatilize and drive off the i substrate.
~ he bakiny operation, represented in Figure 15 by an oven S8, may be the conventional "bake-out" operation during which the phosphor binder and the afore-described smookhing layer or "film" deposited to form a base for the evapora,ed aluminum layer, are driven off. Thus, since a bake-out opera-tion is required as a necessary step in the conventional manu-facture of a cathode ray tube, the removal of the substrate 12 and the adhesive layer 16 can be achieved without the necessity of adding any special tube processing operations.
The invention is not limited to the particular details of construction of the embodiments depicted and other modifi-cations and applications are -contemplated. Certain changes 25 may be made in the above-described methods and apparatus without departing from the true spirit and scope of the invention herein involved. For example, to minimize the possibility of blistering of the metal layer during the baXe-out operation, the metal layer deposited upon the substrate may be caused to have tiny per-forations whi~h will serve ultimately as out-gassing openings for the materials volatilized under the metal layer. In the Fig~res 1-8 embodiment, rather than using a release agent, as -12~
~ ~ ~53~
described, satisfactory results may be obtainable by the use of a non-stic]s substrate, the sur:Eace of whi.ch inherently has low adherance to the metal layer. Alternatively, other forces than adhesion, e.g., electrostatic, may be employed to hold the metal layer upon the strippable suhstrate until. the transfer of the metal layer is accomplished. Whereas in the above-described methods the binder in the phosphor layer -to which the metal layer is transferred is described a.s a photosensitized binder, the invention is e~ually applicable to transferring a metal layer onto phosphor layers ha.ving non-sensitized organic binders or phosphor layers of other compositions. It is intended, therefore, that the subject matter of the above depiction shall be interpreted as illustrative and not in a limiting sense.
. .
. ~ .
Claims (14)
1. A method for metalizing a phosphor screen on the faceplate of a cathode ray tube, comprising:
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate and a layer of electrically conductive, light-reflective metal deposited thereon;
adhering the web to the phosphor layer on the inner surface of the faceplate; and removing the substrate to leave a phosphor screen covered with a layer of the metal.
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate and a layer of electrically conductive, light-reflective metal deposited thereon;
adhering the web to the phosphor layer on the inner surface of the faceplate; and removing the substrate to leave a phosphor screen covered with a layer of the metal.
2. A method for metalizing a phosphor screen on the faceplate of a cathode ray tube, comprising:
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate, a release agent deposited on the substrate and a layer of electrically conductive, light-reflective material deposited on the release agent;
adhering the web to the phosphor layer on the inner surface of the faceplate;
stripping off the substrate; and baking the faceplate to drive off at least the binder.
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate, a release agent deposited on the substrate and a layer of electrically conductive, light-reflective material deposited on the release agent;
adhering the web to the phosphor layer on the inner surface of the faceplate;
stripping off the substrate; and baking the faceplate to drive off at least the binder.
3. A method for metalizing a phosphor screen on the faceplate of a cathode ray tube, comprising:
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate and a layer of electrically conductive, light-reflective metal deposited on the substrate;
applying to the layer of metal a pressure sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer;
stripping off the substrate; and removing at least the binder and the adhesive to leave a phosphor screen covered with a layer of the metal, said removing step including baking the faceplate.
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate and a layer of electrically conductive, light-reflective metal deposited on the substrate;
applying to the layer of metal a pressure sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer;
stripping off the substrate; and removing at least the binder and the adhesive to leave a phosphor screen covered with a layer of the metal, said removing step including baking the faceplate.
4. A method for metalizing a phosphor screen on the faceplate of a cathode ray tube, comprising:
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate, a release agent deposited on the substrate, and a layer of electrically conductive, light-reflective metal deposited on the release agent;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400 °C, uniformly pressing the adhesive coated web against the phosphor layer on the inner surface of the faceplate;
stripping off the substrate; and baking the faceplate to drive off at least the binder and the adhesive so as to leave a phosphor screen covered with a layer of the metal.
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable sheet substrate, a release agent deposited on the substrate, and a layer of electrically conductive, light-reflective metal deposited on the release agent;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400 °C, uniformly pressing the adhesive coated web against the phosphor layer on the inner surface of the faceplate;
stripping off the substrate; and baking the faceplate to drive off at least the binder and the adhesive so as to leave a phosphor screen covered with a layer of the metal.
5. The method defined by claim 4 wherein said web comprises a thermoplastic material and wherein said step of draping the web over a mandril includes heating the web during the draping operation to cause the web to assume the exact contour of the mandril.
6. A method for metalizing a phosphor screen on the faceplate of a color cathode ray tube, comprising:
depositing on the inner surface of a color cathode ray tube faceplate phosphor layers containing red-emissive, blue-emissive and green-emissive phosphor materials held in a volatilizable binder;
forming an aluminum transfer web by depositing a layer of aluminum upon a flexible, deformable sheet substrate;
draping the web over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer;
stripping off the substrate; and baking the faceplate to drive off at least the binder and the adhesive to thereby leave a phosphor screen covered with a layer of aluminum.
depositing on the inner surface of a color cathode ray tube faceplate phosphor layers containing red-emissive, blue-emissive and green-emissive phosphor materials held in a volatilizable binder;
forming an aluminum transfer web by depositing a layer of aluminum upon a flexible, deformable sheet substrate;
draping the web over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer;
stripping off the substrate; and baking the faceplate to drive off at least the binder and the adhesive to thereby leave a phosphor screen covered with a layer of aluminum.
7. A method for metalizing a phosphor screen on the faceplate of a color cathode ray tube, comprising:
depositing on the inner surface of the faceplate a light-absorptive layer extending to the sides of the faceplate beyond the viewed area thereof and having openings therein for receiving phosphor material;
depositing on the openings in the light-absorptive layer phosphor elements comprising interleaved patterns of red-emissive, blue-emissive and green-emissive phosphor materials held in a photosensitized binder;
forming an aluminum transfer web by depositing a release agent upon a flexible, deformable sheet substrate and upon the release agent depositing a layer of aluminum;
draping the web over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer and to a marginal portion of the light-absorptive layer around the patterns of phosphor elements;
stripping off the substrate; and baking the faceplate to remove at least the binder and the adhesive to leave a phosphor screen covered with a layer of aluminum extending radially beyond the screen and onto said marginal portion of said light-absorptive layer.
depositing on the inner surface of the faceplate a light-absorptive layer extending to the sides of the faceplate beyond the viewed area thereof and having openings therein for receiving phosphor material;
depositing on the openings in the light-absorptive layer phosphor elements comprising interleaved patterns of red-emissive, blue-emissive and green-emissive phosphor materials held in a photosensitized binder;
forming an aluminum transfer web by depositing a release agent upon a flexible, deformable sheet substrate and upon the release agent depositing a layer of aluminum;
draping the web over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above about 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer and to a marginal portion of the light-absorptive layer around the patterns of phosphor elements;
stripping off the substrate; and baking the faceplate to remove at least the binder and the adhesive to leave a phosphor screen covered with a layer of aluminum extending radially beyond the screen and onto said marginal portion of said light-absorptive layer.
8. A method for metalizing a phosphor screen on the faceplate of a cathode ray tube, comprising:
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable volatile sheet substrate and a layer of electrically conductive, light-reflective metal deposited on the substrate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer; and baking the faceplate to drive off the binder, adhesive and substrate and thereby leaving a phosphor screen covered with a layer of the metal.
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web comprising a flexible and deformable volatile sheet substrate and a layer of electrically conductive, light-reflective metal deposited on the substrate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer; and baking the faceplate to drive off the binder, adhesive and substrate and thereby leaving a phosphor screen covered with a layer of the metal.
9. The method defined by claim 8 wherein said substrate is composed of an acrylic resin.
10. A method for metalizing a phosphor screen on the faceplate of a cathode ray tube, comprising:
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web com-prising a flexible and deformable dissoluble sheet substrate and a layer of electrically conductive, light-reflective metal deposited on the substrate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer; and removing the binder, adhesive layer and substrate to leave a phosphor screen covered with a layer of the metal, the removing operation including dissolving the substrate and baking the faceplate to drive off at least the binder and the adhesive.
depositing on the inner surface of a cathode ray tube faceplate a phosphor layer containing a phosphor material and a volatilizable binder;
draping over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate a web com-prising a flexible and deformable dissoluble sheet substrate and a layer of electrically conductive, light-reflective metal deposited on the substrate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer; and removing the binder, adhesive layer and substrate to leave a phosphor screen covered with a layer of the metal, the removing operation including dissolving the substrate and baking the faceplate to drive off at least the binder and the adhesive.
11. The method defined by claim 10 wherein said web comprises a thermoplastic material selected from the group consisting of nitro-cellulose, and wherein said step of dissolving the substrate comprises washing the faceplate with a cellulose solvent.
12. A method for metalizing a phosphor screen on the faceplate of a color cathode ray tube, comprising:
depositing on the inner surface of a color cathode ray tube faceplate phosphor layers containing red-emissive, blue-emissive and green-emissive phosphor materials held in a volatilizable binder;
forming an aluminum transfer web by depositing a layer of aluminum upon a dissoluble, flexible, deformable sheet substrate;
draping the web over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer; and removing the binder, adhesive and substrate to leave a phosphor screen covered with a layer of aluminum, the removing operation including dissolving the substrate and baking the faceplate to drive of at least the binder and the adhesive.
depositing on the inner surface of a color cathode ray tube faceplate phosphor layers containing red-emissive, blue-emissive and green-emissive phosphor materials held in a volatilizable binder;
forming an aluminum transfer web by depositing a layer of aluminum upon a dissoluble, flexible, deformable sheet substrate;
draping the web over a mandril having generally the contour of the inner surface of the cathode ray tube faceplate;
applying to the layer of metal a pressure-sensitive adhesive capable of being converted to a gaseous form if heated to temperatures above 400°C;
uniformly pressing the adhesive-coated web against the phosphor layer on the inner surface of the faceplate to cause the web to adhere firmly to the phosphor layer; and removing the binder, adhesive and substrate to leave a phosphor screen covered with a layer of aluminum, the removing operation including dissolving the substrate and baking the faceplate to drive of at least the binder and the adhesive.
13. A cathode ray tube in process, comprising:
a glass faceplate;
a phosphor layer on the inner surface of the faceplate containing a phosphor material and a volatilizable binder;
a layer of pressure-sensitive adhesive on said phosphor layer;
a layer of electrically conductive, light-reflective metal on said layer of adhesive; and a layer of flexible, deformable sheet material on said layer of metal.
a glass faceplate;
a phosphor layer on the inner surface of the faceplate containing a phosphor material and a volatilizable binder;
a layer of pressure-sensitive adhesive on said phosphor layer;
a layer of electrically conductive, light-reflective metal on said layer of adhesive; and a layer of flexible, deformable sheet material on said layer of metal.
14. A cathode ray tube in process, comprising:
a transparent faceplate;
a phosphor layer on the inner surface of the faceplate containing a phosphor material and a binder;
a layer of pressure-sensitive adhesive on said phosphor layer;
a layer of electrically conductive, light-reflective metal on said layer of adhesive;
a release agent on said layer of metal; and a stripping layer of flexible, deformable sheet material on said release agent.
a transparent faceplate;
a phosphor layer on the inner surface of the faceplate containing a phosphor material and a binder;
a layer of pressure-sensitive adhesive on said phosphor layer;
a layer of electrically conductive, light-reflective metal on said layer of adhesive;
a release agent on said layer of metal; and a stripping layer of flexible, deformable sheet material on said release agent.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US429604A US3910806A (en) | 1974-01-02 | 1974-01-02 | Method for metalizing a cathode ray tube screen |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1053992A true CA1053992A (en) | 1979-05-08 |
Family
ID=23703949
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA212,528A Expired CA1053992A (en) | 1974-01-02 | 1974-10-29 | Methods and structures for metalizing a cathode ray tube screen |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3910806A (en) |
| CA (1) | CA1053992A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4153494A (en) * | 1975-12-12 | 1979-05-08 | Enrique Vilaprinyo Oliva | Process for obtaining brightly metallized surfaces |
| US4209551A (en) * | 1977-12-28 | 1980-06-24 | Toppan Printing Co., Ltd. | Method of fabricating a phosphor screen of a color television picture tube |
| US4215170A (en) * | 1978-02-28 | 1980-07-29 | Eurographics Holding, N. V. | Metallization process |
| US4407685A (en) * | 1979-07-23 | 1983-10-04 | Ford Aerospace & Communication Corporation | Metallized film transfer process |
| US4897151A (en) * | 1988-07-27 | 1990-01-30 | General Dynamics Corp., Pomona Division | Method for fabricating a dichroic parabolic lens reflector |
| EP0382554A3 (en) * | 1989-02-10 | 1992-09-30 | Matsushita Electric Industrial Co., Ltd. | Method of forming a metal-backed layer and a method of forming an anode |
| US5639330A (en) * | 1990-03-14 | 1997-06-17 | Matsushita Electric Industrial Co., Ltd. | Method of making an image display element |
| JP3348290B2 (en) * | 1992-02-24 | 2002-11-20 | ソニー株式会社 | Method for forming phosphor screen and apparatus for forming phosphor screen |
| JP2001328229A (en) * | 2000-05-23 | 2001-11-27 | Sony Corp | Transfer film, method for forming thin film of panel for display device thereby, and display device having thin film formed by the method |
| US6906455B2 (en) * | 2001-02-26 | 2005-06-14 | Sony Corporation | Transfer foil, transfer method, transfer apparatus, flat cathode-ray tube, and its manufacturing method |
| FR2854099B1 (en) * | 2003-04-28 | 2006-09-22 | Sylvie Lecomte | COVER OF RECOVERY AND METHOD OF MANUFACTURING |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2734013A (en) * | 1956-02-07 | myers | ||
| US2828435A (en) * | 1954-01-04 | 1958-03-25 | Hoyt Karl Robert | Method of making television screen and decalcomania therefor |
| US3340121A (en) * | 1963-12-20 | 1967-09-05 | Carl F Lawrenz | Method of applying decorative coatings to metal parts |
| US3434902A (en) * | 1965-07-20 | 1969-03-25 | Diamond Int Corp | Method and system for transferring heat-activated labels |
| FR1539879A (en) * | 1967-08-08 | 1968-09-20 | Cellophane Sa | Metallization of fabrics by transfer |
-
1974
- 1974-01-02 US US429604A patent/US3910806A/en not_active Expired - Lifetime
- 1974-10-29 CA CA212,528A patent/CA1053992A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3910806A (en) | 1975-10-07 |
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