US3546525A - Electron gun electrical connection apparatus - Google Patents

Description

DeC- 8^ 1970 AKlo oHGosHl ETAL 3,546,525

ELECTRON GUN ELECTRICAL CONNECTION APPARATUS Filed Jan.v 21, 1969 2 Sheets-Sheet 1 Amo oHGosHl SEN/e1 MlvAoKA av ATTORNEY ELECTRON GUN ELECTRICAL CONNECTION APPARATUS Filed Jan. 21, 1969 Dec. 8, 1970 AKlo oHGosl-u ETAL 2 Sheets-Sheet 2 IN VENTORS AKIO OHGOSHI SENRI MIYAOKA ATTORNEY United States Patent O U.S. Cl. 315-13 12 Claims ABSTRACT OF THE DISCLOSURE The gun structure of a color picture tube of the singlegun, plural-beam type is provided with a resilient contact to engage a conductive member which extends through the tube neck portion, and a tube-contained conductive layer, respectively, for applying operating voltages to the electron beam deflection plates of the gun disposed within the tube. In addition, the conductive member is located to inhibit electrical discharge between such conductive member and the externally disposed deflection yoke, and the external and internal surfaces of the tube neck portion are maintained substantially free of projections or the like to facilitate tube manufacture.

This invention relates generally to color picture tubes of the single-gun, plural-beam type, and particularly to tubes of that type in which the plural beams are passed through the optical center of a common electron lens by which the beams are focused on the color phosphor screen.

In single-gun, plural beam color picture tubes of the described type, for example, as specifically disclosed in the copending United States application Ser. No. 697,414, filed Jan. 12, 1968, now Pat. No. 3,448,316, and having a common assignee herewith, three laterally spaced electron beams are emitted by a beam generating or cathode assembly and directed in a common substantially horizontal plane with the central beam coinciding with the optical axis of the single electron focusing lens and the two outer beams being converged to cross the central beam at the optical center of the lens and thus emerge from the latter along paths that are divergent from the optical axis. Arranged along such divergent paths are pairs of convergence deflecting plates having voltages applied thereacross to laterally deflect the divergent beams in a substantially horizontal plane for causing all beams to converge at a point on the apertured beam selecting grid or shadow mask associated with the color screen.

In such color picture tubes, the beam generating assembly, electron focusing lens and convergence deflecting plates are assembled together as a unit to form the single gun structure which is inserted into the neck portion of the glass envelope further having a conical portion extending from the neck portion and terminating in a face on which the color screen is provided.

This invention is particularly directed to the means by which voltages are applied to the convergence deflecting plates of the described unitary gun structure for effecting the desired convergence of the beams.

Tubes of the described type further have horizontal and vertical deflection coils for appropriate deflection of the electron beams to effect scanning of the screen, and such coils are embodied in a yoke assembly to be dis- 3,546,525 Patented Dec. 8, 1970 ice posed around the tube where the neck portion and conical portion meet. In the manufacture of the tubes, it is preferable that the deflection yoke assembly, which is of generally torus-like configuration, be pre-assembled and simply slid over the neck portion to the position thereof adjacent the juncture of the neck and conical portions. Accordingly, it may be understood that any protuberances or projections in the nature, for example, of operating voltage pickups which extend from the surface of the neck portion will interfere with this sliding of the deflection yoke assembly thereover to thus complicate tube manufacture.

In addition, and with regard to the operation of such tubes, it may be understood that the voltages to be applied to the gun structure within the neck portion in order to operate electron beam deflection means to provide for proper convergence of the plural electron beams at the tube face or screen are of very substantial magnitude inthe order, for example, of 13 to 20 kv. Thus, it will readily be understood that the point of application thereof to the gun structure must not be disposed too closely to parts of the tube at substantially different voltages, as otherwise a significant problem of electrical discharge therebetween results.

Further, and referring again to the manufacturing processes utilized in the production of such tubes, it will be understood that the gun structure, which includes the plural beam generating means, the focusing lens and the convergence deflecting means, and which is generally manufactured as a unit outside the tube envelope and then inserted into the neck portion, has to be precisely positioned therein. Accordingly, if anything other than a substantially smooth surface is provided at the interior of the tube neck portion, this will interfere with the free passage of the gun structure through the tube neck portion to the requisite position thereof to thereby further complicate the tube manufacturing process.

It is, accordingly, an object of this invention to provide a single-gun, plural-beam color picture tube of the described character having means for applying the necessary operating voltages to the convergence deflection means in a manner to avoid the above-mentioned problems.

Another object is to provide a color picture tube of the single-gun, plural-beam type wherein the external surface of the tube neck portion is of substantially smooth configuration to facilitate the sliding of the electron beam deflection yoke assembly thereover into operative position on the tube.

Still another object is the provision of a color picture tube as above wherein the external point of application of the convergence deflecting voltage to the tube is sufficiently spaced from the deflection yoke assembly and from any gun structure at a very substantially different potential to substantially inhibit electrical discharge therebetween.

A further object is to provide a color picture tube as above wherein the interior surface of the tube neck portion is also of substantially smooth configuration to facilitate the insertion of the unitary gun structure thereinto during tube manufacture.

`In accordance with an aspect of this invention, the voltages for operating the convergence deflecting means of the unitary gun structure are applied thereto through first and second resilient contact members, such as springs, Iwhich project from the gun structure and respectively irmly contact the usual conductive layer on the inner surface of the conical portion of the tube envelope and having the anode voltage applied thereto and a conductive button or member provided in the side wall of the tube neck portion at a location spaced from the deflection yoke assembly and preferably adjacent an electrode of the focusing lens which receives a voltage not substantially different from the voltage to be applied to such neck button.

rIhe resilient contact which engages the conductive layer at the interior of the tube envelope to receive the anode voltage may be connected directly to the respective plates of the convergence deflecting means, and the other resilient contact for engagement with the neck button may be connected to the respective convergence deecting plates either through a conductor or through an electrode or electrodes of the focusing lens.

The above, and other objects, features and advantages of this invention, will be apparent in the following detailed description of illustrative embodiments which is to be read in conjunction with the accompanying drawings, wherein:

FIG. 1 is an axial sectional view of a single-gun, pluralbeam color picture tube constructed in accordance with a first embodiment of this invention;

FIG. 2 is a transverse sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a view similar to that of FIG. 1, but showing a single-gun, plural-beam color picture tube constructed in accordance with a second embodiment of this invention;

FIG. 4 is a transverse sectional vieW taken on line 4-4 of FIG. 3;

FIG. 5 is another view similar to that of FIG. 1, but showing a single-gun, plural-beam color picture tube constructed in accordance with a third embodiment of this invention;

FIG. 6 is a transverse sectional view taken along line 6--6 of FIG. 5;

FIG. 7 is an enlarged longitudinal sectional view of the neck portion of color picture tubes in the nature of those depicted in FIGS. 1, 3 and 5, and particularly shows means to provide a deecting voltage to a conductive member disposed in such neck portion; and

FIG. 8 is a transverse sectional view taken along line 8 8 in FIG. 7.

Referring now to the color picture tube embodiment of FIGS. 1 and 2, it will be understood that the arrangement and manner of operation thereof are similar to those disclosed in the copending United States application Ser. No. 697,414 which is more fully identified above. The color picture tube of the embodiment of FIGS. 1 and 2 is of the single-gun, plural-beam type and includes the conventional tube envelope as indicated generally at E and which comprises in turn a generally cylindrical, tube neck portion N and an integral generally conical tube portion C constructed from any suitable, non-conductive material in the nature of glass.

A single gun is disposed in the tube neck portion N and, at the end of the latter remote from the conical portion C, includes a cathode assembly K which comprises :beam generating sources KR, KG and KB, respectively. A iirst control grid G1 is provided to substantially surround the electron beam generating sources, and such control grid has apertures gu' g12 and g13 which are respectively aligned as shown with the beam generating sources.

A common grid G2, having apertures g2b g22 and g23, is disposed as shown in opposed, adjacent relationship to the grid G1, and the respective apertures of the common grid G2 are formed in substantial alignment with the respective apertures in the control grid G1. Arranged in order following the grid G2 in the direction away from the cathode assembly K are successive, openended generally tubular grids or electrodes G3, G4 and G5. The several electrodes G3, G4 and G5, grids G1 and G2 and cathode assembly K are assembled together and maintained in the relative positions shown by means of longitudinally extending insulating beads 22 and 22 arranged at circumferentially spaced locations around the gun structure and being connected to the several parts thereof by radial pins anchored in the beads. The gun structure is `positioned within the neck portion N of the tube envelope by slidable engagement of beads 22 and 22 with the inner surface of neck portion N and further by the engagement with such inner surface of the peripheries of axially spaced rings 30 and 31 fixed on an extension of electrode G5.

A plurality of conductive pins 21 extend as shown through the end wall 20 of neck portion N, and conductive leads 21 are provided to connect such pins to control grid G1, common grid G2, and electrode G4 for the provision of suitable operating voltages thereto. Further, a conductor 19 connects electrodes G3 and G5 so that the latter will have the same potential applied thereto.

With the supply of appropriate opearting voltages to control grid G1, common grid G2, and electrode G4 through the medium of the interconnected pins 21 and leads 21', and the supply of an appropriate operating voltage to the electrodes G3 and G5 in the manner described in detail hereinbelow, an electron lens field is established between grid G2 and the adjacent end of electrode G3, which electron lens eld will correspond to an auxiliary lens as indicated in dashed lines at L', and further an electron lens field corresponding to a main focusing lens as indicated in dashed lines at L is formed at the axial center of the electrode G2 by the electrodes G3, G4 and G5. Thus, the electron beams BB, BR Which emanate from the electron beam generating sources KB and KB will be made to converge by auxiliary lens L to cross each other at the optical center of the main focusing lens L, with the central electron beam BG which extends along the optical axis of lens L emerging from the latter undeected, and the electron beams BB and BR emerging therefrom, as shown, along diverging paths.

In order to subsequently reconverge the electron beams BB and BR with the electron beam BG at a common spot in a nonillustrated grid or shadow mask which is disposed just before the nonillustrated face or color screen of the color picture tube, all in a manner disclosed in detail in the copendng application for United States patent Ser. No. 697,414 referred to hereinabove, the gun structure of the color picture tube shown in FIGS. 1 and 2 further comprises electron beam deflecting means as indicated generally at F. The deflecting means F may comprise a pair of spaced, opposed shielding plates P and P which extend axially of the color picture tube, and a pair of spaced, convergence deecting plates Q and Q which are disposed in spaced, opposed relationship with the respective outer surfaces of the shielding plate P and P.

The shielding plates P and P are maintained in the depicted positions thereof by conductive angle members 23 which function to support the plates P and P from the adjacent end of the previously mentioned extension of electrode G5. Further, laterally spaced bridging members 26 connect the ends of plates P and P remote from electrode G5 to establish electrical connections between such plates and to maintain the connected ends of the plates in the desired spaced relationship. The convergence detiecting plates Q and Q are supported from beads 25 and 25 of any suitably insulative material which are in turn supported from the respective shielding plates P and P by support pins 24 and 24', respectively. Thus, the convergence deecting plates Q and Q' will be supported from the dellecting plates P and P without electrical connection therebetween. By this construction, the respective shielding plates and convergence deflecting plates P, P', Q and Q are disposed in such manner that the electron beam BB will pass between the convergence deflecting plate Q andthe shielding plate P, the electron beam BG will pass between the shielding plates P and P', and the electron beam BR will pass between the shielding plate P and the convergence defiecting plate Q.

For operation of the electron beam defiecting means F, it will be understood that the application of suitable operating voltages thereto will be required. More specifically, it will be required that a first high voltage, for example of the order of 13 to 20 kv., be applied to shielding plates P and P', and that a second high voltage which differs somewhat from the first voltage, for example, by 200 to 300 V., be applied to the convergence deecting plates Q and Q whereby potential differences of 200 to 300 v. will be established between the respective plates Q and P, and Q and P to thus provide for the desired electrostatic deflection of the respective electron beams BB and BR, while enabling the undeflected passage of the electron beam BG between the shielding plates P and P' which will be maintained at the same potential.

As seen in FIG. 1, a conductive layer 28 is applied to the interior surface of the conical portion C and extends into the adjacent part of neck portion N of the color picture tube envelope E. It is to be understood that the tube anode voltage is applied at an anode button (not shown) to the conductive layer 28 to be available thereat. Since, in this instance, it is desired that this anode voltage be applied to shielding plates P and P', and therefrom, through the conductive angle members 23 and 23 to the electrode G5, and from the latter through connecting lead 19 to the electrode G3, a coil spring 27 of any suitably conductive material is connected, in any convenient manner, to one of the bridging members 26 and extends therefrom in the manner best seen in FIG. 2 into firm surface contact with conductive layer 28. Thus, as a result of the application of the anode voltage to conductive layer 28, the provision of the coil spring 2'7, and the interconnection of the respective shielding plates P and P' with the electrodes G5 and G3, application of the said anode voltage to the said shielding plates and electrodes Will be accomplished.

For application of a convergence deecting voltage to the respective convergence deflecting plates Q and Q', a lead 40 is provided and extends as shown to connect the said deflecting plates to each other, and a lead 36 is connected to the defecting plate Q to extend therefrom rearwardly of the tube neck portion N. A getter chamber support member 32 is mounted between support rings 30 and 31, and in turn supports getter chamber container means 33 to provide for the formation of a getter chamber 34. The getter chamber 34 functions in conventional manner to remove traces of free gases from the interior of the tube envelope E. The lead 36 is passed through the getter chamber 34 as shown by the extension of the said lead through aligned apertures provided in support rings 30- and 31, and an insulating sleeve 35 surrounds the lead 36 as shown for obvious purpose.

A conductive member or button 39 is disposed in the neck portion N of the color picture tube envelope E and button 39 terminates in a shoe 38 which extends somewhat as shown circumferentially of the tube neck portion N. As best seen in FIG. 7, the outer extremity of the button 39 and the inner surface of the button shoe 38 are disposed substantially flush with the respective ex ternal and internal surfaces of the tube neck portion N, it being understood, however, that although this substantially flush disposition of the button 39 relative to the external and internal tube neck portion surfaces is preferably from the standpoint of ease of electrical connection thereto, the primary concern, for reasons made clear hereinbelow, is that no portion of button 39 project beyond either of the said tube neck portion surfaces.

The lead 36 terminates adjacent the button shoe 39, and a second conductive coil spring 37 is there connected to conductive lead 36 to extend therefrom into firm surface contact with the button shoe 38 to provide for an electrical connection therebetween. Thus, a defiecting voltage which is applied to the button 39 in the envelope neck portion N will in turn be applied, through coil spring 37 and lead 36, to deflecting plates Q and Q'.

For a typical application of the color picture tube according to the embodiment of FIG. l, the anode voltage, which is applied through the conductive layer 28, coil spring 27 and bridging member 26, to shielding plates P and P', will be in the range of 13 to 20 kv., while the deflecting voltage which is applied, through button 39, coil spring 37 and conductive lead 36, to deflecting plates Q and Q' will be generally equivalent to the anode voltage minus 200l to 300 v.

Application of the deiiecting voltage to the conductive member or button 39 is effected by the appropriate connection thereto of a lead carrying such voltage. More specifically, and as best seen in FIGS. 7 and 8, a shoe 70 of any suitably insulative and readily bendable material in the nature, for example, of a suitable plastic or synthetic rubber, is provided to extend around the exterior surface of the tube neck portion N, and the shoe 70 has flanges 72 and 74 through which attachment means in the nature of bolts 76 may be extended and tightened to firmly secure the shoe around the tube neck portion. A generally bulbous portion 78 extends from shoe 70 and has an aperture 79 formed therein through which a suitably insulated lead '80 which carries the defiection voltage extends. A female-type connector member 82 is disposed as shown in an enlarged extremity of shoe aperture 79, and the end of lead 80, and a straight end portion of a coil spring 84 of any suitably conductive material, are soldered and/or pressed together, as illustrated, into firm surface contact within female-type conductive member 82. The coil spring 84 extends from member `82 beyond the inner surface of shoe 70 and into firm contact with the button 39, whereby the defiecting voltage carried on lead 82 will be applied to button 39 for subsequent application to the deflecting plates Q and Q' as described hereinabove.

An electron beam deflection yoke assembly, indicated in dashed lines at D in FIG. l, includes the usual horizontal and vertical deflection coils to cause beams BB, BG and BR to scan the color screen (not shown) on the tube face. Such yoke assembly D is of generally toroidal configuration and its internal dimensions are selected so that the yoke assembly will fit closely on the tube neck portion N. Since the conductive member or button 39 does not extend beyond the outer surface of neck portion N, the button 39 does not interfere with sliding of previously fabricated yoke assembly D onto neck portion N to its normal operative position as shown. After such positioning of the yoke assembly, shoe 70` can be secured around neck portion N for providing the electrical connection from lead 80 to button 39.

Further, since the shoe 38 of button 39 does not project substantially beyond the inner surface of neck portion N, the gun structure of the tube can be assembled as a unit outside the tube envelope and merely slidably inserted axially into neck portion N to engage the resilient contacts 27 and 37 of the gun structure with con ductive layer 28 and button shoe 38, respectively. When thus positioned within neck portion N, the gun structure is firmly and accurately located by engagement of in beads 22 and 22' and its rings 30- and 31 with the internal surface of the neck portion. Thus, manufacture of the color picture tube is substantially facilitated.

It will also be noted that button 39 by which the high convergence deflection voltage is applied for transmission to plates Q and Q is substantially spaced from yoke assembly D on neck portion N whereby to inhibit the possibility of external electrical discharge becharge between button 39, or the lead 80` connected thereto, and the deflection yoke assembly. Further, since button 39 is provided in the side Wall of neck portion N, such button for supplying the high convergence deflecting voltage to plates Q and Q is substantially spaced from the terminal joint 21 extending through end wall 20 of the neck portion and which supply the very substantially smaller voltages to cathode assembly K, grids G1 and G2 and lens electrode G4. Thus, external electrical discharge between button 39 and pins 21 is also inhibited.

Within neck portion N, the engagement of resilient contact 37 with the shoe 38 of button 39 occurs at a location adjacent an electrode of the gun structure having7 applied thereto a voltage that is not very substantially different from the voltage applied at button 39. Thus, in the embodiment of FIG. l, button 39 is located adjacent electrode G5 which has applied thereto a voltage, for example of 13 to 20 kv., which is only 200 to 300 v. greater than the voltage applied by wayV of button 39. Thus, electrical discharge between the point of contact of spring 37 with shoe 38 and electrode G5 is not a serious danger.

Referring now to the embodiment of FIGS. 3 and 4, it may be seen that the construction and arrangement of the color picture tube there illustrated are substantially the same as described hereinabove with respect to FIGS. l and 2, except for the convergence depicting means thereof. Accordingly, the several components of the tube in FIGS. 3 and 4 are identified by the same reference characters as the like components in FIGS. 1 and 2.

In the embodiment of FIGS. 3 and 4, the electron beam convergence dellecting means are again indicated generally at F but, in this instance, are seen to comprise first electron beam deilecting means as indicated generally at F1, and second electron beam deflecting means arranged in succession thereto and indicated generally at F2. Divergent-convergent electron beam deflection means of this nature are disclosed in detail, for example in the copending application of Ohgoshi et al., entitled New and Improved Color Picture Tube System, Ser. No. 718,738, filed Apr. 4, 1968, now Pat. No. 3,467,881, and assigned to the assignee hereof. Included in the electron beam deilecting means F1 are spaced, opposed shielding plates P and P which extend as shown from an adjacent end face of the tube electrode G5 and are supported therefrom and electrically connected thereto through conductive angle brackets 23 and 23.

The dellecting means F1, which are effective to cause additional divergence of the beams BB and BR emerging from the focusing lens along divergent paths, further comprise divergence deflecting plates Q1 and Q1', which are disposed in spaced, opposed relationship to the outer surfaces of shielding plates P and P', respectively, and are supported in the depicted positions from the shielding plates by support pins 56 and 56' extending therebetween and insulative beads 55 and 55' which connect the respective dellecting plates Q1 and Q1' to the support pins while maintaining the plates Q1 and Q1' electrically insulated from the plates P and P'.

The dellecting means F2 which function to converge beams BB and BR comprise a first pair of spaced deflecting plates H and H' which are disposed in spaced opposed relationship to the outer surfaces of shielding plates P and P', and a second pair of deflecting plates Q2 and Q2' which are disposed in spaced, opposed relationship to the outer surfaces of dellecting plates H and H', respectively. The dellectng plates Q2 and Q2' are supported from shielding plates P and P' by conductive angle plates 53 and 53' extending therebetween, while dellecting plates H and H' are supported from the respective deilecting plates Q2 and Q2' by insulative beads 57 and 57' disposed therebetween. Leads 51 and 51' electrically connect the deilecting plates H and Q1, and deflecting plates H and Q1', respectively. With this construction, and upon the application of appropriate voltages thereto as described in detail directly hereinbelow, the shielding plates P and P and the dellecting plates Q2 and Q2' will be at the same potential. In like manner, deflecting plates Q1, Q1', H, and H', will also be at the same potential.

For application of the anode voltage from the conductive layer 28 to deflecting plates Q1, Q1', H and H', coil springs 52 and 52 of any suitably conductive material, are connected as indicated to each of leads 51 and 51 and arranged to extend therefrom into firm surface contact with the conductive layer 28 in neck portion N of tube envelope E.

Application of the dellecting voltage from the conductive member or button 39 disposed in neck portion N to extend therethrough and be flush with, or in any event not project beyond, the external and internal surfaces thereof, is effected by a conductive coil spring 54 which is connected to the electrode G5 and extends therefrom into firm surface contact button shoe 38. Accordingly, with the application of the deflecting voltage to the button 39 effected through the use of insulated lead 80 in the manner described hereinabove with reference to FIGS. 7 and 8, such voltage is transmitted through conductive spring 54, electrode G5 and conductive angle brackets 23 and 23', to shielding plates P and P' and therefrom, through conductive angle plates 53 and 53', to deflecting plates Q2 and Q2. Thus, suitable potential differences will be established between the shielding plates P and P' and the divergence dellecting plates Q1 and Q1', and suitable potential differences will also be established between convergence dellecting plates Q2 and H, and Q2' and H.

In the operation of the color picture tube of the ernbodiment of FIGS. 3 and 4, the central electron beam BG is again passed undeflected between shielding plates P and P', while the electron beam BB is initially passed between the shielding plate P and the dellecting plate Q1, for initial deflection in a direction which is divergent to the central electron beam BG and then the electron beam BB is passed between the deflecting plates Q2 and H for deflection in a direction convergent with the central electron beam BG. In like manner, the electron beam BR is initially passed between shielding plate P' and dellecting plate Q1' for deflection in a direction divergent to the central electron beam BG, and is passed therefrom between dellecting plates H and Q2' for convergent deflection relative to the electron beam BG. As discussed hereinabove with regard to the operation of the embodiment of FIGS. l and 2, it may be understood that the operation of the dellecting means F of the embodiment of FIGS. 3 and 4 is effective to provide for convergence of the electron beams BB, BG and BR at a common spot in a nonillustrated grid or shadow mask disposed just prior to the nonillustrated face or color screen of the color picture tube.

Consideration of the construction and manner of operation of the embodiment of FIGS. 3 and 4 is believed to make clear that the color picture tube thereof offers the same significant advantages with regard to ease of anode and deflection voltage application, inhibition of external voltage discharge between the deflection voltage applying means and the deflection yoke means, and ease of tube color picture manufacture, as are discussed in detail hereinabove with regard to the embodiment of FIGS. l and 2.

Referring now to FIGS. 5 and 6, it will be seen that the construction and arrangement of the gun structure in a color picture tube, as there illustrated, are substantially the same as described in detail hereinabove with regard to the embodiment of FIGS. 1 and 2. Accordingly, like reference characters are again utilized to identify like tube components. In the embodiment of FIGS. 5 and 6, it is, however, desired to apply the anode voltage to the plates Q and Q' rather than the shielding plates P and P', and, for this purpose, a conductive leaf spring 90 is connected to the deilecting plate Q' and extends therefrom into firm surface contact with the conductive layer 28 to which is again applied the anode voltage.

In this embodiment, the deflecting voltage is again applied by means of the insulated lead 80 (FIG. 7) to conductive member or button 39 in the tube neck portion N and, in this instance, the conductive coil spring 37 is connected as indicated to the electrode G3 to extend therefrom into firm surface contact with the button shoe 38 to effect application of the deflecting voltage to electrode G3. From electrode G3, this deflecting voltage is supplied, by means of a lead 60, to the electrode G5, and the deilecting voltage is applied from the latter, through the conducive angle members Z3 and 23', to the respective shielding plates P and P.

In the embodiment of FIGS. 5 and 6, the voltage applied to button 39 is greater than the anode voltage carried by conductive layer 28. Thus, shielding plates P and P' will be at the same potential, while potential differences will be established between plates Q and P, and plates Q' and P', whereby the central electron beam BG will pass undeflected between the said shielding plates and electron beams BB and BR will be deflected toward the central electron beam by the respective passages thereof between the plates Q and P and plates Q and P' for ultimate convergence of all of the electron beams in the manner described hereinabove.

In addition to the significant advantages discussed hereinabove with regard to the embodiments of FIGS. l and 2, and FIGS. 3 and 4, respectively, which advantages are, of course, also provided 'by the embodiment of FIGS. 5 and 6, it may be understood that, in the latter embodiment, the connection of button 39 to electrode G3 makes possible the disposition of such button even further rearwardly of the deection yoke D to thus even further inhibit external electrical discharge between the latter and the deflection yoke.

It will be apparent that many modifications and variations in addition to those noted above may be effected in the described embodiments without departing from the spirit and scope of this invention as defined in the appended claims.

We claim:

1. In a color picture tube having a neck portion and a generally conicalportion terminating in a face having a color screen thereon, electron gun means disposed in said neck portion for directing a plurality of electron beams toward said color screen, electron beam focusing lens means disposed in said neck portion intermediate said electron gun means and said screen for focusing said electron beams on said color screen and having an optical center through which said beams are all passed with at least two of said beams emerging from said lens means along paths divergent to the optical axis thereof, said focusing lens means comprising a plurality of successively arranged electrodes, electron beam deflecting means disposed in said neck portion intermediate said focusing lens means and said screen and being operative to deflect said beams emerging along said divergent paths for convergence of said beams at a common point on said screen, said deflecting means compn'sing a plurality of pairs of spaced plates, and a conductive layer on the interior surface of said conical portion having an anode voltage applied thereto and extending at least adjacent to said tube neck: the improvements comprising, means for applying said anode voltage to at least one of said plate pairs and comprising conductive resilient means which are electrically connected to said at least one plate pair and extend into contact with said conductive layer, and means for applying a different voltage to at least another of said plate pairs, the last-mentioned means comprising a conductive member disposed in a side wall of said tube neck portion at a location corresponding generally to the location therein of said electron beam focusing lens means and which does not project beyond the external surface of said tube neck portion.

2. A tube as in claim 1, wherein said last-mentioned means further comprise conductive resilient means elec- 10 trically connected to said at least another plate pair and extending into contact with said conductive member.

3. A color picture tube as in claim 1, wherein said conductive member does not project substantially beyond the internal surface of said tube neck portion.

4. A color picture tube as in claim 1, wherein said last-mentioned means further comprise a lead connected to said at least another of said plate pairs and extending rearwardly therefrom to a location adjacent said conductive member, and conductive resilient means electrically connected to said lead and extending therefrom into contact with said conductive member.

5. A color picture tube as in claim 4, wherein said at least one plate pair comprises spaced shielding plates disposed in opposed relationship, and said at least another of said plate pairs comprise spaced deecting plates disposed in spaced, opposed relationship with the respective outer surfaces of said shielding plates.

6. A color picture tube as in claim 1, wherein said last-mentioned means further comprise means electrically connecting said at least another of said plate pairs to one of said focusing lens electrodes, said electrode extending rearwardly to a location adjacent said conductive member, and conductive resilient means electrically connected to said electrode and extending therefrom into contact with said conductive member.

7. A color picture tube as in claim 6, wherein said at least another of said plate pairs comprises spaced shielding plates disposed in opposed relationship, and a rst pair of spaced deflecting plates disposed in spaced, opposed relationship with the respective outer surfaces of said shielding plates and electrically connected thereto, and said at least one plate pair comprises second and third pairs of longitudinally spaced deflecting plates, said second pair of deflecting plates being disposed in spaced, opposed relationship with the respective outer surfaces of said shielding plates, and said third pair of deecting plates being disposed intermediate said shielding plates and said first pair of deecting plates and spaced therefrom, and means electrically connecting said second and third dellecting plate pairs.

8. A color picture tube as in claim 1, wherein said last-mentioned means further comprise means electrically connecting said at least another of said plate pairs to a lirst of said focusing lens eletcrodes, means extending rearwardly in said neck portion and electrically connecting said first focusing lens electrode to a second of said focusing lens electrodes which extends in turn rearwardly to a location adjacent said conductive member, said first and second focusing lens electrodes being spaced by at least a third focusing lens electrode, and conductive resilient means eletcrically connected to said second focusing lens electrode and extending therefrom into contact with said conductive member.

9. A color picture tube as in claim 8, wherein said at least another of said plate pairs comprise spaced shield ing plates which are disposed in opposed relationship, and said at least one plate pair comprises spaced deflecting plates which are disposed in spaced, opposed relationship with the outer surfaces of said shielding plates.

10. A color picture tube as in claim 1, wherein said last-mentioned means further comprise voltage applying means disposed externally of said tube neck portion and including conductive resilient means which extend into contact with said conductive member externally of said tube neck portion for applying said different voltage thereto.

11. A color picture tube as in claim 10, wherein said conductive resilent means to contact said conductive member is mounted in an insulating member removably wrapped around said neck portion of the tube.

12. A color picture tube as in claim 1, wherein deflection yoke means are disposed around said color picture tube at the juncture of said tube neck and conical portions, and said conductive member is disposed in said 11 12 tube neck portion substantially rearwardly of said de- 3,448,316 6/ 1969 Yoshida etal. ection yoke means. 2,721,287 10/1955 Ormer.

References Cited RICHARD A. FARLEY, Primary Examiner UNITED STATES PATENTS 5 M. F. HUBLER, Assistant Examiner 2,269,115 1/1942 Koch 315-15 2,347,797 5/1944 Posthumus et al. 315-15 U-S- C1- X-R- 2,887,598 5/1959 Benway 315-13X 174-5053; `3'13 7() 3,275,881 9/1966 Hynes et al. 315-13

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