CA1184234A - Cathode-ray tube with double coined electrode - Google Patents
Cathode-ray tube with double coined electrodeInfo
- Publication number
- CA1184234A CA1184234A CA000382787A CA382787A CA1184234A CA 1184234 A CA1184234 A CA 1184234A CA 000382787 A CA000382787 A CA 000382787A CA 382787 A CA382787 A CA 382787A CA 1184234 A CA1184234 A CA 1184234A
- Authority
- CA
- Canada
- Prior art keywords
- recess
- depression
- electron gun
- coined
- coining
- 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
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
-
- 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
- H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
- H01J29/48—Electron guns
- H01J29/488—Schematic arrangements of the electrodes for beam forming; Place and form of the elecrodes
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Electrodes For Cathode-Ray Tubes (AREA)
- Microwave Tubes (AREA)
- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
Abstract
ABSTRACT:
An electron gun electrode is provided with an improved beam shaping region having an elongated recess coined in the upper electrode surface and an opposed coined depression in the lower surface. The double coining fabrication method assures a sharp perimetrical edge about at least the central portion of the recess, such being an important influence in achieving improved beam shaping lensing.
An electron gun electrode is provided with an improved beam shaping region having an elongated recess coined in the upper electrode surface and an opposed coined depression in the lower surface. The double coining fabrication method assures a sharp perimetrical edge about at least the central portion of the recess, such being an important influence in achieving improved beam shaping lensing.
Description
PH~. 60.002 The invention relates to a method of fabricating a cathode-ray tube comprising in an evacuated envelope an electron g~m to generate an electron beam and a target for receiving said electron beam, the electron glm including a cathcde and at least two grid elec-trodes, a discretely configurated beam shaping region being fabricatedin at least one of the grid electrodes, said region having a one-piece effectual portion evidencing upper and lower surfaces defining a material thickness therebetween.
Such cathode-ray tubes are used to display, for example, tele-vision pictures or are used in an oscilloscope. In such cases the tar-get is a display screen having a phosphor layer, for example, in a black-and-white ~isplay tube or in an oscilloscoFe tube, or having a pattern of phosphor elements luminescing in different colours in a colou~ display tuke.
Such a tube may also be used as a camera tube. In that case the target is a photosensitive layer, for example, a photoconductive layer.
In all applications the spot formed when the electron beam impinges on the target must have predeterrnined, generally small, dimen-sions and the haze surrounding the target should be minimum.
Such a method is disclosed in the publi.shed Canadian Patent1,112,284 - Bijma et al issued November 10, 1981 (PHN 8960). In the first grid electrode of the electron gun of the cathode ray tube des-cribed in said specification an aperture and a V-shaped or U-shaped groove is provided. This first ele.ctrode with groove consti-tu-tes, in cooperation with the second grid, a non-rotationally symmetrical elec-tron lens, this asymmetry becaming manifest mainly as a quadrupole lens action focusing the electron beam in tw~ focal lines instead of one con-centrated stigmatic cross-over (waist). To permit such grooves to be made, a comparatively thick plate material has to be used.
Some beam shaping electrodes have been manufactured as tw~~
piece structures in an effort to achieve the desired beam fo7~ning characteristics. For example, the article "30AX Self-aligning 110 ~`
FHA. 60.002 2 in-line color TV display" in lLL~ Transactions on Consume~s Electronics, Vol. CE-24 Mo. 3, August 1978, pp. 481-487 discloses beam shaping elec trodes constructed of two superimposed rectanguk~rly slotted elements affixed in orthogonal relationship to provide a substantially square aperture there-through. mrough these slo-ts the first gcid electrode, in cooperation with the cathode, forms a first elec-trostatic quadrupole lens field and, in cooperation with the second grid electrode, forms a second electrostatic quadrupole lens field rotated 90 with LespeCt to the first electrostatic quadrupole lens field. The electron beam is focused in two focal lines by said lens fields so that the mutual repelling of the electrons (space charge repelling) becomes less than in the case of one concentrated stigmatic cross-over. In fabrication, it is difficult to keep proper alignment between the two slots, and the affimral welding can produce surface imperfections which are dele-terious to the forming of the desired beam shapulg lensing.
Generaliy speaking, the use of beam shaping electrodes inelectron guns to beneficially modify the lensing of the beams is kncwn in the art. Discrete beam shapingsmin~ize deflected spot distortion, such being especially true when self converging yokes are employed with in-line gun tubes. Electrodes with beam shaping properties provide a lensing field of equipotential lines of force to form the bundle of moving electrons into a beam of desired cross-sectional shaping .
Exemplary art is also evidenced in U.S. Patent Nos. 3,852~608 - Johannes et al issued December 3, 1974~ 3,866,081 - Hasker et al issued 25 February 11, 1975 and 4,143,293 - Hasokoshi et al - issued March 6, 1979.
It is therefore an object of this invention to reduce and obviate the aforementioned disadvantages and to provide a rnethod of facilely fabricating a cathode ray tube comprising an improved dis-cretely configurated beam shaping region in a grid electrode.
Another object of the invention is to provide a method of fabricating a one-piece beam sha~ing electron gun electrode tha-t e~idences improved be~m forming properties.
PE~ 60.002 3 14.07.1981 .~ccording to the invention such a ~etho~ is chclracterized m that sald method comprises the steps of coinina an elongated recess inward fron~ said upper surface; coinlng a depression lnward from said lower surface in opposed orientation to said recess coining to e~pedite a EIow of electrocle material to rhe upper coinina reaion, thereby promo-ting the formation oE a substantially sharp periilletrical edge in at leas-t the central reaion of said recess shapir.a; and forming an aperture thrcucrh the residual electrode material interme~iate ~he bottoms of said coined recess and said coined depression to co3rplete In said bea3n shap mg configuration.
The electrode fabrica-tion procedure utilizing the afore-mentioned opposed coining makes -the electrode material flow in a manner -to assure the fonnation of a beneficially sharp per~n~etrical edge at least partially a~out the upper surface rela-ted recess. This sharp edge perime-ter, in the region of the apert~re, markedly augmellts -the beam-shaping properties of the configuration, thereby promoting an umr proved lensing effect which beneficially modifies the cross-sectional shaping of the beam in the desired manner.
~qoreover, the electrode is also comparatively thin in the re-gion of the aperture.
Fig. 1 is a cross-sectional view of a catho~e-ray -tube fabri-cated according to the invention;
Fig. 2 is an enlarged sectional view of a portion of an electron gun showing the initial beam shaplng region thereof;
Fig 3 is a sectional perspective view of the improved beam shaping electrode;
Fig. 4 is a plan view of -the same, taken along the line 4-4 of Fig. 3;
Fig. 5 is a sectional view of the electrode blank prior to imparting hea~n shapir.g proper-ties thereto; and Fia,. 6 is a sectional perspective view illustrating fabrication of the electroce.
For a better ~Iderstandinq of the presen-t invention together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims -taken in conjunction with the aforedescrih~ed drawings.
For pur?oses of illustration, a color catnode ray tube emplo-ying an apertured mask and an in-line plural gun electron generating PHA 60.002 4 ~ 14.07.19d1 assernbly ~7ill be :initially desccibed m this specifica-tiorl as an e~emplary sett~r.c~ for the invention. It is understood that such is not to ~e consldere~ 'uni~ing to the concept of the inven-tion.
With particular reference -to Fig. 1, -the essentials of a plural in-line beam color cathode ray tube construction 11 are showrl.
The encompassing envelope is colnprised of an integra-tion of neck 13, furnel 15 and face panel 17 portions. A pa-t-terned catho~olum:Lnescent screen 19 of color-emi-tting phosphor areas lS disposed on the in-terior -surface of the viewing panel 17 as an array of definitive stripes or O dots, in !ceeping with -the state of the art. ~ multlple apertured struc-ture 21, in thls instance a shadowrnask, is spatially related -to the patterned screen; such being located wlthin the panel by conventional means, no-t shown.
Positioned wi-thin tlle lleC~ portion l3 of the envelope is an lS elec-tron gun assembly 23 cornprlsed of several rela-ted electron guns, each of which procluces a respective electron beam 25, 27 and 29. While not shown, each of these individual guns includes a ca-thode and a plurality of sequentially arranged cooperating electrc~le elements which are formed and spaced to provide the source~ forrnation, acceleration and fccusing of the respective electron beam in a ma~uler -to properly impinge the screen 19.
Positioned externally of the tube 11 is a deflection yoke 31 which deflects the beams in a c'etermined manner -to provide an image display raster upon the screen. Wi-th the accep-tance in the art of self-converging deflection yokes, a need has arisen for improve~ edge-of-screen focus 33. Thus, an irnprovernent in the beam forming region of each electron g~m is of importan-t significance.
In referring to Figs. 2, 3 and 4, there is shown an e.~emplary enlarged sectional view of the rear beam forming region of one of the electron guns of the gun assembly 23. This shown por-tion of the ~un stnlcture includes a thermionic cathode s-tructure 35 having e~ternal electron emissive ma-terial 37 terrl~inally disposed thereon, such being aetivated by an internally positioned heating element 39. Positioned adjacent thereto is a first or control grid electrode (G1) 41 having a one-piece effectual por-tion 43 transversely oriented to the path of the beam bundle of electrons 45. This effectual portion evidences an upper surface 47 and a lower surface 49, such defining a ma-terial thickness "T" therebetween. The shcwn effectual portion 43 of the control electrode Pl~ 60.002 5 41 may be an ele~ent of several electrode constructions. For example, it can be the bottom part of an individual cup-shaped (G1) mem~er, or a subst.~ntially planar dish-shaped portion of an ln-t~ra-tecl (G1) ascembly u-tilizina a common grid pLane for a plurali-ty of guns. The in-5 vention relates -to the improved beam shaping region regardless of the over-all construction of ~he electrode.
Formeci in the electrode effectlal portion 41 of the contrcl electrode is the i~proved beam shaping region 5l, which, in conjunction with the spatially related apertured second or screen grid electrode (G2) 53 in c~ operating gun, provides c~ initial beam lensing influence in -the inter-electrode spacing 5~ therebetween. The contoured confiau-ration of the (G1) beam shaping region 51, adjacent the aperture 55 therethrough, and the related apertured effectual portion 57 of the second (G2) electrode, toaether influence shaping of the array of equipotential lines of force constituting the lensing in a manner to beneficially modify the shaping of the beam bundle of electrons 45 passing therethrough.
In greater detail, the improved configurc~ted beam shaping region in the control electrode 41 has an elongated recess 59 for~ed, as by coining, inward from the upper surface 47 thereof. The term "coining" as used herein refers to the deforma-tion of material by applied pressure, whether or not the deformed material is con-tained in a die cavity. This recess, which is free of surface imperfections, has a definecl width "W", length "L" and depth "D", and as exemplarily shown, is suhstantially rec-tangular in shape. There may be occasions when -the desired lensing effec-ts may re~uire a more ovate modified shaping. It is an important lens forming consideratlon that this recess evidences a substantially sharp perime-trical edge 61 at least partially thereabout. This is usually difficult to achieve in a stamping or coining operation per se since such pressure techniques tend to form a slightly rolled or radiused edge.
To achieve the desired sharp edge 61 about at least the central region of the recess 59, a depression 63 is fom~ed, as ~y coining, inward from the lower surface ~9 of the control electrode 41 3s in opposed orientation to the upper surface-related recess 59. These upper and lower related coining operations produce a beneficial flow of electrode material. This lower surface depression is exemplarily shown as being circular in shape, but it too, may be of a modified cvate Pl~ 60.OG2 6 sha ing. Its di~ ter ^- longest lateral dir~ension "B" shoulcl b~? suffi-clent to prcvide a flow of materlal -to at least the central periTr~rical region of tl~e related re~ess ~9. The resiclual electrode material 6l inter-m~iiate the kotton b5 of the recess and the kottom 67 o--' the depression evldencc?s a t~lickness "t". In one ~Yarnple of s-~nlctural relationships, the depth "D" of the recess 59 does not e~Yceed the -thickness "t" of the residual material, and the depth "d" of the depression 63 is less tha the thickneàs "t" of the residual materlal. r~S shown in ~ig. 2, the depression b3 is dimensioned to accommodate positioniny of he catnoe 35 in close spatial relationship with the kottom surface of the cor,trol (G1) electrode. Such accom~odation tends to effect a degree of shieidinq for the emlssive surface of the cathode.
~ n aperture 55 is formeà throuql1 the residual materlal 64 in symmetrical relationship with the recess 59 and the depression 63 ~5 to comple-te the urproved configurated beam shaping region 51.
This aperture is eYemplarily sho~n as being circular in shaping, ~lt such is not to be considered limiting. Regardless of :its shaping, its width cr diametrical dinension "A", is slightly less than the width dimension ll~,~TII of -the recess. Suci1 dimensional relationship, as shown in Figs. 3 and 4~ allows a clean aperture to be formed through the residual material 64 without damaging the sharp periunetrical edge ~1 of the recess or scarring the sidewalls thereof.
Regarding fabrLcation of the beam shaping config~ra-tion of the electrode, reference is directecl to Fig. 5 wherein there is sho~n a grid blank for the conl-rol (G1) electrode 41. The effectual portion is defined by the perireter 69, in this ins-tance circular, with the upper surface 47 and the lower surface 49 thereof clefining a given thickness thereL^e-tween. This blank is positioned in a tooling arrangement 71 as sho~n in F`ig. 6. With the blank resting on a bottom anvil m~mber, 72 a top forming die 73, having a defined projection 75, is pressured against an appropriate part of the upper surface of the electrode blar~ 41 in a manner to coin the substantially rectangular recess 59 therein. Preferably simultaneously, a movable coining die 77, contained for sliding operation within anvil member 72, is pressurecl against -the lower surface 49 of the blank to coin the substantially circular de-pression ~3 in the lo~er surface thereof. The resultant flow of material effectecl by the colning of the depression, forces some of the flcw material to the top forrning die to fill in t~e inherently round eclge P~ 60.00~ 7 ~i~out the recess 59, thereby prornoting the formation or the sllbstan-tiallv sharp perirrRtrical edae ~1 a~out a-t least the central portion thereof.
This is an ir~ortant tabrica-tion consideration, since the sharp edae of the recess, par-tlcularly in the region of the aperture, subsequen-tlv efEects a Leneficlal improvement ul the beam shaping lensing.
The beam aperture 55 is thence provided in -the coined realon, being orlented as heretofore c~escribed. Thus, the forming of the confic~lrated beam shaping region is completed.
Utilization of -the aforedescribed double-coining fabrication pxocedure and -the resultant ~mproved electrc~e st~uchire form~xl thereby obviate many of the disadvantages evidences in the prior art.
The e]ectron g m electrode structure of cathocle ray tu~e Eabricated by the method according -to -the invention incorporates the forming of a d:iscretely confic~lrated beam shaping region which con-tributes to unproved lensing influencing the initial shaping of thebeam. The economical and expeditious double coined fabrica-tion proce-dure assures -the achievement of the beneficially sharp perimetrical edge in at least the critical region of the recess portion of the configura-tion. The one-piece electrode structure reduces mc~nufacturing costs, and overcomes further disadvantages of tne two-piece structures of -the prior art by eliminating the inaccuracies of multiple piece assembly and the possible presence of weld ~rrs on critical surfaces.
3~
Such cathode-ray tubes are used to display, for example, tele-vision pictures or are used in an oscilloscope. In such cases the tar-get is a display screen having a phosphor layer, for example, in a black-and-white ~isplay tube or in an oscilloscoFe tube, or having a pattern of phosphor elements luminescing in different colours in a colou~ display tuke.
Such a tube may also be used as a camera tube. In that case the target is a photosensitive layer, for example, a photoconductive layer.
In all applications the spot formed when the electron beam impinges on the target must have predeterrnined, generally small, dimen-sions and the haze surrounding the target should be minimum.
Such a method is disclosed in the publi.shed Canadian Patent1,112,284 - Bijma et al issued November 10, 1981 (PHN 8960). In the first grid electrode of the electron gun of the cathode ray tube des-cribed in said specification an aperture and a V-shaped or U-shaped groove is provided. This first ele.ctrode with groove consti-tu-tes, in cooperation with the second grid, a non-rotationally symmetrical elec-tron lens, this asymmetry becaming manifest mainly as a quadrupole lens action focusing the electron beam in tw~ focal lines instead of one con-centrated stigmatic cross-over (waist). To permit such grooves to be made, a comparatively thick plate material has to be used.
Some beam shaping electrodes have been manufactured as tw~~
piece structures in an effort to achieve the desired beam fo7~ning characteristics. For example, the article "30AX Self-aligning 110 ~`
FHA. 60.002 2 in-line color TV display" in lLL~ Transactions on Consume~s Electronics, Vol. CE-24 Mo. 3, August 1978, pp. 481-487 discloses beam shaping elec trodes constructed of two superimposed rectanguk~rly slotted elements affixed in orthogonal relationship to provide a substantially square aperture there-through. mrough these slo-ts the first gcid electrode, in cooperation with the cathode, forms a first elec-trostatic quadrupole lens field and, in cooperation with the second grid electrode, forms a second electrostatic quadrupole lens field rotated 90 with LespeCt to the first electrostatic quadrupole lens field. The electron beam is focused in two focal lines by said lens fields so that the mutual repelling of the electrons (space charge repelling) becomes less than in the case of one concentrated stigmatic cross-over. In fabrication, it is difficult to keep proper alignment between the two slots, and the affimral welding can produce surface imperfections which are dele-terious to the forming of the desired beam shapulg lensing.
Generaliy speaking, the use of beam shaping electrodes inelectron guns to beneficially modify the lensing of the beams is kncwn in the art. Discrete beam shapingsmin~ize deflected spot distortion, such being especially true when self converging yokes are employed with in-line gun tubes. Electrodes with beam shaping properties provide a lensing field of equipotential lines of force to form the bundle of moving electrons into a beam of desired cross-sectional shaping .
Exemplary art is also evidenced in U.S. Patent Nos. 3,852~608 - Johannes et al issued December 3, 1974~ 3,866,081 - Hasker et al issued 25 February 11, 1975 and 4,143,293 - Hasokoshi et al - issued March 6, 1979.
It is therefore an object of this invention to reduce and obviate the aforementioned disadvantages and to provide a rnethod of facilely fabricating a cathode ray tube comprising an improved dis-cretely configurated beam shaping region in a grid electrode.
Another object of the invention is to provide a method of fabricating a one-piece beam sha~ing electron gun electrode tha-t e~idences improved be~m forming properties.
PE~ 60.002 3 14.07.1981 .~ccording to the invention such a ~etho~ is chclracterized m that sald method comprises the steps of coinina an elongated recess inward fron~ said upper surface; coinlng a depression lnward from said lower surface in opposed orientation to said recess coining to e~pedite a EIow of electrocle material to rhe upper coinina reaion, thereby promo-ting the formation oE a substantially sharp periilletrical edge in at leas-t the central reaion of said recess shapir.a; and forming an aperture thrcucrh the residual electrode material interme~iate ~he bottoms of said coined recess and said coined depression to co3rplete In said bea3n shap mg configuration.
The electrode fabrica-tion procedure utilizing the afore-mentioned opposed coining makes -the electrode material flow in a manner -to assure the fonnation of a beneficially sharp per~n~etrical edge at least partially a~out the upper surface rela-ted recess. This sharp edge perime-ter, in the region of the apert~re, markedly augmellts -the beam-shaping properties of the configuration, thereby promoting an umr proved lensing effect which beneficially modifies the cross-sectional shaping of the beam in the desired manner.
~qoreover, the electrode is also comparatively thin in the re-gion of the aperture.
Fig. 1 is a cross-sectional view of a catho~e-ray -tube fabri-cated according to the invention;
Fig. 2 is an enlarged sectional view of a portion of an electron gun showing the initial beam shaplng region thereof;
Fig 3 is a sectional perspective view of the improved beam shaping electrode;
Fig. 4 is a plan view of -the same, taken along the line 4-4 of Fig. 3;
Fig. 5 is a sectional view of the electrode blank prior to imparting hea~n shapir.g proper-ties thereto; and Fia,. 6 is a sectional perspective view illustrating fabrication of the electroce.
For a better ~Iderstandinq of the presen-t invention together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims -taken in conjunction with the aforedescrih~ed drawings.
For pur?oses of illustration, a color catnode ray tube emplo-ying an apertured mask and an in-line plural gun electron generating PHA 60.002 4 ~ 14.07.19d1 assernbly ~7ill be :initially desccibed m this specifica-tiorl as an e~emplary sett~r.c~ for the invention. It is understood that such is not to ~e consldere~ 'uni~ing to the concept of the inven-tion.
With particular reference -to Fig. 1, -the essentials of a plural in-line beam color cathode ray tube construction 11 are showrl.
The encompassing envelope is colnprised of an integra-tion of neck 13, furnel 15 and face panel 17 portions. A pa-t-terned catho~olum:Lnescent screen 19 of color-emi-tting phosphor areas lS disposed on the in-terior -surface of the viewing panel 17 as an array of definitive stripes or O dots, in !ceeping with -the state of the art. ~ multlple apertured struc-ture 21, in thls instance a shadowrnask, is spatially related -to the patterned screen; such being located wlthin the panel by conventional means, no-t shown.
Positioned wi-thin tlle lleC~ portion l3 of the envelope is an lS elec-tron gun assembly 23 cornprlsed of several rela-ted electron guns, each of which procluces a respective electron beam 25, 27 and 29. While not shown, each of these individual guns includes a ca-thode and a plurality of sequentially arranged cooperating electrc~le elements which are formed and spaced to provide the source~ forrnation, acceleration and fccusing of the respective electron beam in a ma~uler -to properly impinge the screen 19.
Positioned externally of the tube 11 is a deflection yoke 31 which deflects the beams in a c'etermined manner -to provide an image display raster upon the screen. Wi-th the accep-tance in the art of self-converging deflection yokes, a need has arisen for improve~ edge-of-screen focus 33. Thus, an irnprovernent in the beam forming region of each electron g~m is of importan-t significance.
In referring to Figs. 2, 3 and 4, there is shown an e.~emplary enlarged sectional view of the rear beam forming region of one of the electron guns of the gun assembly 23. This shown por-tion of the ~un stnlcture includes a thermionic cathode s-tructure 35 having e~ternal electron emissive ma-terial 37 terrl~inally disposed thereon, such being aetivated by an internally positioned heating element 39. Positioned adjacent thereto is a first or control grid electrode (G1) 41 having a one-piece effectual por-tion 43 transversely oriented to the path of the beam bundle of electrons 45. This effectual portion evidences an upper surface 47 and a lower surface 49, such defining a ma-terial thickness "T" therebetween. The shcwn effectual portion 43 of the control electrode Pl~ 60.002 5 41 may be an ele~ent of several electrode constructions. For example, it can be the bottom part of an individual cup-shaped (G1) mem~er, or a subst.~ntially planar dish-shaped portion of an ln-t~ra-tecl (G1) ascembly u-tilizina a common grid pLane for a plurali-ty of guns. The in-5 vention relates -to the improved beam shaping region regardless of the over-all construction of ~he electrode.
Formeci in the electrode effectlal portion 41 of the contrcl electrode is the i~proved beam shaping region 5l, which, in conjunction with the spatially related apertured second or screen grid electrode (G2) 53 in c~ operating gun, provides c~ initial beam lensing influence in -the inter-electrode spacing 5~ therebetween. The contoured confiau-ration of the (G1) beam shaping region 51, adjacent the aperture 55 therethrough, and the related apertured effectual portion 57 of the second (G2) electrode, toaether influence shaping of the array of equipotential lines of force constituting the lensing in a manner to beneficially modify the shaping of the beam bundle of electrons 45 passing therethrough.
In greater detail, the improved configurc~ted beam shaping region in the control electrode 41 has an elongated recess 59 for~ed, as by coining, inward from the upper surface 47 thereof. The term "coining" as used herein refers to the deforma-tion of material by applied pressure, whether or not the deformed material is con-tained in a die cavity. This recess, which is free of surface imperfections, has a definecl width "W", length "L" and depth "D", and as exemplarily shown, is suhstantially rec-tangular in shape. There may be occasions when -the desired lensing effec-ts may re~uire a more ovate modified shaping. It is an important lens forming consideratlon that this recess evidences a substantially sharp perime-trical edge 61 at least partially thereabout. This is usually difficult to achieve in a stamping or coining operation per se since such pressure techniques tend to form a slightly rolled or radiused edge.
To achieve the desired sharp edge 61 about at least the central region of the recess 59, a depression 63 is fom~ed, as ~y coining, inward from the lower surface ~9 of the control electrode 41 3s in opposed orientation to the upper surface-related recess 59. These upper and lower related coining operations produce a beneficial flow of electrode material. This lower surface depression is exemplarily shown as being circular in shape, but it too, may be of a modified cvate Pl~ 60.OG2 6 sha ing. Its di~ ter ^- longest lateral dir~ension "B" shoulcl b~? suffi-clent to prcvide a flow of materlal -to at least the central periTr~rical region of tl~e related re~ess ~9. The resiclual electrode material 6l inter-m~iiate the kotton b5 of the recess and the kottom 67 o--' the depression evldencc?s a t~lickness "t". In one ~Yarnple of s-~nlctural relationships, the depth "D" of the recess 59 does not e~Yceed the -thickness "t" of the residual material, and the depth "d" of the depression 63 is less tha the thickneàs "t" of the residual materlal. r~S shown in ~ig. 2, the depression b3 is dimensioned to accommodate positioniny of he catnoe 35 in close spatial relationship with the kottom surface of the cor,trol (G1) electrode. Such accom~odation tends to effect a degree of shieidinq for the emlssive surface of the cathode.
~ n aperture 55 is formeà throuql1 the residual materlal 64 in symmetrical relationship with the recess 59 and the depression 63 ~5 to comple-te the urproved configurated beam shaping region 51.
This aperture is eYemplarily sho~n as being circular in shaping, ~lt such is not to be considered limiting. Regardless of :its shaping, its width cr diametrical dinension "A", is slightly less than the width dimension ll~,~TII of -the recess. Suci1 dimensional relationship, as shown in Figs. 3 and 4~ allows a clean aperture to be formed through the residual material 64 without damaging the sharp periunetrical edge ~1 of the recess or scarring the sidewalls thereof.
Regarding fabrLcation of the beam shaping config~ra-tion of the electrode, reference is directecl to Fig. 5 wherein there is sho~n a grid blank for the conl-rol (G1) electrode 41. The effectual portion is defined by the perireter 69, in this ins-tance circular, with the upper surface 47 and the lower surface 49 thereof clefining a given thickness thereL^e-tween. This blank is positioned in a tooling arrangement 71 as sho~n in F`ig. 6. With the blank resting on a bottom anvil m~mber, 72 a top forming die 73, having a defined projection 75, is pressured against an appropriate part of the upper surface of the electrode blar~ 41 in a manner to coin the substantially rectangular recess 59 therein. Preferably simultaneously, a movable coining die 77, contained for sliding operation within anvil member 72, is pressurecl against -the lower surface 49 of the blank to coin the substantially circular de-pression ~3 in the lo~er surface thereof. The resultant flow of material effectecl by the colning of the depression, forces some of the flcw material to the top forrning die to fill in t~e inherently round eclge P~ 60.00~ 7 ~i~out the recess 59, thereby prornoting the formation or the sllbstan-tiallv sharp perirrRtrical edae ~1 a~out a-t least the central portion thereof.
This is an ir~ortant tabrica-tion consideration, since the sharp edae of the recess, par-tlcularly in the region of the aperture, subsequen-tlv efEects a Leneficlal improvement ul the beam shaping lensing.
The beam aperture 55 is thence provided in -the coined realon, being orlented as heretofore c~escribed. Thus, the forming of the confic~lrated beam shaping region is completed.
Utilization of -the aforedescribed double-coining fabrication pxocedure and -the resultant ~mproved electrc~e st~uchire form~xl thereby obviate many of the disadvantages evidences in the prior art.
The e]ectron g m electrode structure of cathocle ray tu~e Eabricated by the method according -to -the invention incorporates the forming of a d:iscretely confic~lrated beam shaping region which con-tributes to unproved lensing influencing the initial shaping of thebeam. The economical and expeditious double coined fabrica-tion proce-dure assures -the achievement of the beneficially sharp perimetrical edge in at least the critical region of the recess portion of the configura-tion. The one-piece electrode structure reduces mc~nufacturing costs, and overcomes further disadvantages of tne two-piece structures of -the prior art by eliminating the inaccuracies of multiple piece assembly and the possible presence of weld ~rrs on critical surfaces.
3~
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. A method of fabricating a cathode-ray tube comprising in an evacuated envelope an electron gun to generate an electron beam and a target for receiving said electron beam, the electron gun including a cathode and at least two grid electrodes, a discretely configurated beam shaping region being fabricated in at least one of the grid electrodes, said region having a one-piece effectual portion evidencing upper and lower surfaces defining a material thickness therebetween, characterized in that said method comprises the steps of coining an elongated recess inward from said upper surface; coining a depression in-ward from said lower surface in opposed orientation to said recess coining to expedite a flow of electrode material to the upper coining region, thereby promoting the formation of a substantially sharp perimetrical edge in at least the central region of said recess shaping; and froming an aperture through the residual electrode material intermediate the bottoms of said coined recess and said coined depression to com-plete said beam shaping configuration.
2. The method according to Claim 1, characterized in that the coining of said recess and the coining of said depression are sub-stantially simultaneous operations.
3. The method according to Claim 1, characterized in that said coined recess is of substantially rectangular shaping.
4. The method according to Claim 1, characterized in that said coined depression is of substantially circular shaping.
5. The method according to Claim 1, characterized in that the depth of said coined recess does not exceed half the thickens of said elec-trode material.
6. An improved electron gun electrode member for a cathode-ray tube fabricated by the method according to Claim 1, characterized in that it comprises a one-piece effectual portion transverse to the path of the electron beam associated therewith, said portion evidencing upper and lower surfaces defining a material thickness therebetween and having formed therein an improved discretely configurated beam shaping region comprising: an elongated recess formed inward from said upper surface said recess having defined width, length and depth dimen-sions and evidencing a substantially sharp perimetrical edge in at least the central region thereof; a substantially shallow depression formed inward from said lower surface in opposed orientation to said upper surface-related recess the dimensions of said depression being sufficient to provide a flow of material to at least the central region of said recess perimeter; a residual thickness of original electrode material defined intermediate the bottom of said recess and the bottom of said depression; and an aperture formed through said residual material in symmetrical relationship with said recess and said depression to complete said configurated beam shaping region.
7. The improved electron gun electrode member of Claim 6, characterized in that said depression is substantially circular in shape.
8. The improved electron gun electrode member of Claim 6 characterized in that said depression has a depth less than the thick-ness of said residual material.
9. The improved electron gun electrode member of Claim 6, characterized in that the depth of said recess does not exceed the thickness of said residual material.
10. The improved electron gun electrode member of Claim 6, characterized in that said recess is of substantially rectangular shaping.
11. The improved electron gun electrode member of Claim 6, characterized in that said aperture is substantially circular having a diameter slightly less than the width of said recess.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17516580A | 1980-08-04 | 1980-08-04 | |
| US175,165 | 1980-08-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1184234A true CA1184234A (en) | 1985-03-19 |
Family
ID=22639203
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000382787A Expired CA1184234A (en) | 1980-08-04 | 1981-07-29 | Cathode-ray tube with double coined electrode |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0045547B1 (en) |
| JP (1) | JPS5763746A (en) |
| CA (1) | CA1184234A (en) |
| DE (1) | DE3166330D1 (en) |
| ES (1) | ES504476A0 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1170150B (en) * | 1982-07-19 | 1987-06-03 | Rca Corp | GRID EQUIPPED WITH OPENINGS FOR ELECTRONIC CANNONS AND METHOD OF MANUFACTURE OF THE SAME |
| IT1176203B (en) * | 1983-06-27 | 1987-08-18 | Rca Corp | CATHODE TUBE WITH AN ELECTRONIC CANNON PRESENTING A REGION OF FORMATION OF AN ASTIGMATIC BEAM |
| DE3617432A1 (en) * | 1986-05-23 | 1987-11-26 | Standard Elektrik Lorenz Ag | ELECTRON BEAM GENERATION SYSTEM |
| JP2672502B2 (en) * | 1987-01-26 | 1997-11-05 | 株式会社日立製作所 | Method for manufacturing electrode for color cathode ray tube electron gun |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2935636A (en) * | 1955-10-31 | 1960-05-03 | Rca Corp | Electron gun structure |
| US2971108A (en) * | 1958-09-26 | 1961-02-07 | Sylvania Electric Prod | Electron discharge device |
| US3628077A (en) * | 1970-02-26 | 1971-12-14 | Sylvania Electric Prod | Electron gun having concave coined grid and annular rib |
| US4071932A (en) * | 1976-10-28 | 1978-02-07 | Standaart Adrian W | Method of making electron guns for cathode ray tubes and the like |
| JPS55154044A (en) * | 1979-05-18 | 1980-12-01 | Hitachi Ltd | Electrode structure of electron gun and its manufacture |
-
1981
- 1981-07-21 DE DE8181200833T patent/DE3166330D1/en not_active Expired
- 1981-07-21 EP EP81200833A patent/EP0045547B1/en not_active Expired
- 1981-07-29 CA CA000382787A patent/CA1184234A/en not_active Expired
- 1981-07-31 ES ES504476A patent/ES504476A0/en active Granted
- 1981-08-01 JP JP12003581A patent/JPS5763746A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5763746A (en) | 1982-04-17 |
| DE3166330D1 (en) | 1984-10-31 |
| EP0045547B1 (en) | 1984-09-26 |
| ES8204880A1 (en) | 1982-05-01 |
| ES504476A0 (en) | 1982-05-01 |
| JPH0312417B2 (en) | 1991-02-20 |
| EP0045547A3 (en) | 1982-06-23 |
| EP0045547A2 (en) | 1982-02-10 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |