US3807006A

US3807006A - Method of installing a mount assembly in a multibeam cathode-ray tube

Info

Publication number: US3807006A
Application number: US00302587A
Authority: US
Inventors: J Segro; G Fassett
Original assignee: RCA Corp
Current assignee: RCA Licensing Corp
Priority date: 1972-10-31
Filing date: 1972-10-31
Publication date: 1974-04-30
Anticipated expiration: 1991-04-30
Also published as: GB1453083A; DE2354338A1; DE2354338B2; JPS5331595B2; FR2204875A1; NL179430C; NL179430B; IT996901B; CA995736A; FR2204875B1; NL7314887A; DE2354338C3; JPS4979164A

Abstract

Method includes positioning a bulb assembly including a faceplate panel portion and a mount assembly including a multibeam electron-gun assembly in axial alignment on respective central longitudinal axes thereof. An orientation plane is then defined with reference to the structure of the electron-gun assembly, the orientation plane being at a prescribed angle with a reference plane through the apertures of at least two electron guns and parallel with the central longitudinal axis of the mount assembly. Then the bulb assembly and the mount assembly are rotated with respect to each other on the coincident longitudinal axes until the orientation plane is at a prescribed angle to one of the major or minor axes of the panel portion, thereby providing the desired rotational orientation between the bulb assembly and the mount assembly. Then, while maintaining the rotational orientation, the mount assembly is axially moved within the bulb assembly to a desired longitudinal location with respect to the faceplate panel portion. Then, the bulb assembly and mount assembly are permanently assembled.

Description

United States Patent [1 1 Segro et al.

[451 Apr. 30, 1974 5/l968 Reinvall, Jr 29/25.l3

'Primary Examiner-Roy Lake Assistant ExaminerJ. W. Davie 0r Firm-G. H. Bmestle; L.

Attorney, Agent,

Greenspan ABSTRACT Method includes positioning a bulb assembly including a faceplate panel portion and a mount assembly including a multibeam electron-gun assembly in axial alignment on respective central longitudinal axes thereof. An orientation plane is then defined with reference to the structure of the electron-gun assembly, the orientation plane being at a prescribed angle with a reference plane through the apertures of at least two electron guns and parallel with the central longitudinal axis of the mount assembly. Then the bulb assembly and the mount assembly are rotated with respect to each other on the coincident longitudinal axes until the orientation plane is at a prescribed angle to one of the major or minor axes of the panel portion, thereby providing the desired rotational orientation between the bulb assembly and the mount assembly. Then, while maintaining the rotational orientation, the mount assembly is axially moved within the bulb assembly to a desired longitudinal location with respect to the faceplate panel portion. Then, the bulb assembly and mount assembly are permanently assembled.

9 Claims, 6 Drawing Figures mewus n.

nAPR 30 1974 Min 2 a PATENTEBAPR 30 I974 I I 11807 L 0 sum 3 or 4' PATENTEDAPRBO m I 3807 0 SHEET t UP 4 METHOD OF INSTALLING A MOUNT ASSEMBLY IN A MULTIBEAM CATHODE-RAY TUBE BACKGROUND OF THE INVENTION The invention relates to an improved method of assembling a cathode-ray-tube bulb assembly and mount assembly, and particularly, but not exclusively, to a method of assembling an in-line multibeam electrongun assembly and a color-television-picture-tube bulb of the phosphor line screen type.

In a commercial color television picture tube of the apertured mask type having a three-color, viewingscreen structure, the viewing-screen structure is photographically printed using light centers simulative of the position of the axis of each of the three electron guns in the final tube. A mount assembly comprising three electron guns is subsequently installed in the tube. During the assembly of the electron-gun structure in the final tube, the axis of each electron gun must be oriented to coincide with the light centers used to print the viewing-screen structure within a desired rotational tolerance about the central longitudinal axis of the tube. In commercial color television picture tubes using dynamic convergence circuitry, a mount assembly having three electron guns in fixed orientation ordinarily must be positioned in the tube withinS degrees o f rotation. In a commercial color television picture tub e using no dynamic convergence circuitry or simplified dynamic convergence circuitry, a more accurate rotational positioning of the mount assembly is usually required.

In one prior method for assembling a multiple electron-gun structure, the alignment is accomplished by two separate assembly operations. During the mountassembly operation, the central longitudinal axis of the electron-gun assembly is aligned with the stem axis, and the electron guns are rotationally aligned with the stem leads. Them, the electron-gun assembly is attached to the stem leads with metal wires and ribbons to form a mount assembly. In the subsequent mount-sealing operation, the preassembled mount assembly is positioned and oriented with respect to the bulb assembly and then sealed to the bulb assembly on a sealing unit. The sealing unit holds and orients the bulb assembly rotationally with respect to the major and minor axes and axially with respect to the longitudinal axis of the bulb assembly. The sealing machine also holds and orients the mount assembly axially with respect to the stem, and rotationally with respect to the stern leads. Although this method of alignment is suitable for angular positioning of a mount assembly in some type cathoderay tubes, it is not sufficiently accurate for others.

In the mount-sealing operation, the mount assembly is held rotationally with the stem leads positioned within aligned holes on the sealing machine. Since the holes include a clearance for loading and the mount assembly includes assembly tolerances, the rotational alignment of the mount assembly with respect to the screen structure can only be maintained within 3 of rotation. In addition, since the mount assembly is preassembled and transported to the sealing machine, the fragile wires supporting the electron-gun assembly may be accidentally bent, thereby misaligning the electrongun assembly with the stem leads. This may result in angular misalignment of the electron-gun assembly when the stem leads are used to angularly align the bulb as sembly and the mount assembly. Furthermore, gauging of the amount of angular rotation of the preassembled mount assembly after assembly and gauging of the amount of angular rotation of the mount assembly in the assembled tube may be required to ensure accurate rotational positioning of the electron guns with respect to the viewing-screen structure in the finished tube.

SUMMARY OF THE INVENTION The novel method of assembling a bulb assembly and a mount assembly for a cathode-ray tube is disclosed wherein the mount assembly is oriented rotationally with reference to the electron-gun structure instead of with reference to the stem leads. The bulb assembly has a central longitudinal axis and includes a substantially rectangularly-shaped faceplate portion having a major axis and a minor axis. The mount assembly has a cental longitudinal axis and includes a multibeam electrongun assembly. The novel method includes 1. positioning a bulb assembly in a particular orientation with respect to the central longitudinal axis thereof and one of the major or minor axes thereof,

2. positioning a mount assembly in a location spaced from the bulb assembly with the central longitudinal axis thereof coincident with the central longitudinal axis of the bulb assembly,

3. defining an orientation plane parallel to said axes through at leasttwo spaced points on the structure of the multibeam electron-gun assembly, the orientation plane being at a prescribed angle with a reference plane through the apertures of at least two electron guns and parallel with the central longitudinal axis of the mount assembly,

f}. rotatingthe mount assembly and the bulb assembly on the coincident longitudinal axes with respect to each other until the orientation plane is at a prescribed angle with respect to one of the major or minor axes, thereby providing the desired rotational orientation between the bulb assembly and the electron-gun assembly,

5. then, while maintaining the rotational orientation, moving the mount assembly along the longitudinal axis to a desired longitudinal location with respect to the faceplate panel of the bulb assembly 6. and the permanently fixing the mou r 1 t assembly to the bulb assembly. Y h

Assembling the mount assembly to the bulb assembly with direct rotational alignment of the electron-gun structure with respect to one of the major or minor axes of the faceplate portion eliminates any accumulation of error from preassembly of the mount assembly and from clearance tolerances necessary for loading of the mount assembly on a sealing unit. Also, since the rotational alignment is accomplished immediately prior to the sealing of the bulb assembly and the mount assem bly, accidental misalignment of the preassembled mount assembly does not affect the final tube alignment. In addition, additional requirements of prior gauging of the rotational alignment of a preassembled mount assembly and subsequent gauging of the finished tube after assembly of the mount may be eliminated. The novel method results in accurate rotational alignment of a multiple electron-gun assembly and bulb assembly, eliminates mount rotation scrap and provides economies in manufacture. Furthermore, the accurately rotationally aligned electron-gun assembly and bulb assembly result in a viewed picture of improved quality.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken-away sectional elevational view of a bulb assembly and a mount assembly for a cathoderay tube positioned on a head assembly for a main sealing unit.

FIG. 2 is a plan view of the head assembly and bulb assembly shown in FIG. 1.

FIG. 3 is an enlarged elevational view of a portion of FIG. 1 further illustrating a mount alignment apparatus.

FIG. 4 is a sectional plan view along section lines 4-4 of the apparatus shown in FIG. 3 showing an inline electron gun.

FIG. 5 is an alternative embodiment similar to that shown in FIG. 4 showing a delta electron gun.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a sectional view of a bulb assembly 21 and a mount assembly 22 for a color television picture tube of the apertured-mask type positioned on an apparatus known in the art as a main sealing unit 23 (only partially shown). The main sealing unit 23 is used to install the mount assembly 22 in a precise location and orientation within the bulb assembly 21 to make a color television picture tube assembly, as will be described in the novel method.

COLOR TELEVISION PICTURE TUBE BULB ASSEMBLY A color television picture tube bulb assembly 21 comprises a glass envelope 24, a three-color-phosphor viewing screen structure 25, and an apertured-mask electrode 26. The glass envelope 24 includes a faceplate portion 27, funnel portion 28, and a neck portion 29. The three-color-phosphor viewing screen structure 25 is supported on the inner surface of the faceplate portion 27. The viewing-screen structure 25 is preferably a line-screen structure with phosphor lines extending parallel to the minor axis YY of the bulb assembly 21. The apertured-mask electrode 26 is positioned in the envelope 24 in a predetermined spaced relationship with the viewing-screen structure 25. The apertured-mask electrode 26 used with the line-screen structure 25 includes slot-shaped apertures (not shown). The slot-shaped apertures are positioned parallel to the phosphor lines of the viewing-screen structure 25.

The faceplate panel portion 27 is of a rectangular shape and includes three reference surfaces 30a, 30b and 300 as shown in FIG. 2. The reference surface 30a defines one of the small sides, and the reference surfaces 30b and 30c define one of the large sides of the rectangularly-ahaped faceplate portion 27. The reference surfaces also define the position of a major axis XX and a minor axis YY for the faceplate portion 27. In a VUR90 color television picture tube, the relationship of the position of the major and minor axes to the reference surfaces 30a, 30b and 300 is shown in FIG. 2. The reference surface 30a is at an angle of 3 30 minutes clockwise with respect to a normal line to one of the short sides at the reference surface 30a, and the reference surfaces 30b and 300 are at an angle of 4 clockwise and counterclockwise respectively with respect to a normal line to one of the long sides at the reference surfaces 30b and 300, as shown in FIG. 2. The major axis XX is a distance 31 of 5.332 inches from a line 32, which intersects the references surfaces 30b and 300 at a distance 33 of l0.396 inches. The minor axis YY is a distance 34 of 6.396 inches from an intersection of the 3- 30-minute line, and the reference surface 30a. The minor axis YY is also perpendicular to the major axis XX. The bulb assembly 21 also includes a central longitudinal axis AA, which passes centrally through the neck portion 29 and the intersection of the major axis XX and minor axis YY.

COLOR TELEVISION PICTURE TUBE MOUNT ASSEMBLY The mount assembly 22 comprises a stem assembly 35 and an electron-gun assembly 36. The stem assembly 35 includes a stem 37, exhaust tubulation 38, and stem leads 39. The stem leads 39 are on a 0.600-inchdiameter pin circle and are made of 0.040-inchdiameter wire. The outside diameter of the stem lead circle is concentric with the central longitudinal axis Ar-A of the mount assembly 22.

The electron-gun assembly 36 includes three electron guns and support means between the stem leads 39 and the electron guns 40. An electron gun 40 includes a cathode 41, a control grid or G1 grid 42, a screen grid or G2 grid 43, a first accelerating and focusing grid or G3 grid 44, a second accelerating and focusing grid or G4 grid 45, and a shield cap 46. The various grids are mounted on glass support rods 47. The shield cap 46 may also include bulb spacers 48 for centering the gun assembly within the neck portion 29.

In the 15VUR90 color television picture tube previously described, it is preferred to use an in-line electron-gun assembly 36. An in-line electron-gun assembly 36 includes three electron guns in which the apertures of all of the electron guns are in a line. In one preferred in-line electron-gun assembly 36, such as described in US. patent application to R. H. Hughes, Ser. No. 217,758, dated Jan. 14, 1972, the various electrodes for all three electron guns are each formed in one piece. For example, the G1 grid 42, G2 grid 43, G3 grid 44, and G4 grid are each one piece for the three electron guns.

In the in-line electron-gun assembly 36, the G3 grids are formed in the shape of a lower cup 49a and an upper cup 49b attached at their open ends. Each of the cups includes three in-line apertures 50, one for each of the three in-line electron guns 40. The cups are formed with sides 51 parallel with the center-line 52 through the apertures within O.l of rotation about a central longitudinal axis A A, of the mount assembly. The central longitudinal axis A,-A, of the mount assembly 22 is also coincident with the axis of the center electron gun. The sides of the G3 grid cups 49a and 49b are a distance 53 of 0.190 inch from the centerline 52 through the apertures, and the spacing between the apertures of the two end in-line electron guns is 0.562 inch.

SEALING UNIT It is preferred that a multihead rotary sealing unit 23 (partially shown in FIG. 1) be used to practice the novel method. The rotary unit includes separate processing stations for loading, preheating, sealing, annealing and unloading. The sealing unit 23 includes a rotatable head assembly 54 for each processing station. The head assembly 54 includes a support-frame assembly 55, a bulb-alignment assembly 56, a neck chuck 57, a mount-support assembly 58, a tubulation-lock assembly 59 and a sealing-fire assembly (schematically shown by arrow 60).

The support-frame assembly 55 includes a lower support 61 and an upper support 62. The lower support 61 is rotatably mounted on a main sealing unit 23 in bearings (not shown). The lower support 61 includes two vertical support rods 63. The upper support 62 is mounted at the top of the two support rods 63. The upper support 62 includes a bulb-support member 64 formed to hold the bulb assembly at the yoke reference line as shown in FIG. 1.

The bulb-alignment assembly 56 is also mounted on the upper support 62. The bulb-alignment assembly 56 includes a C-shaped support 65 having three

reference units

66a, 66b, and 66c for orienting the bulb assembly 21 and a bulb-clamp assembly 67 for retaining the bulb assembly 21 against the three reference units.

The neck chuck 57 is mounted on the two vertical rods 63 as shown in FIG. 1. The neck chuck 57 comprises two jaws 68 and actuating means 69 for equally moving the jaws.

The mount-support assembly 58 is mounted on the lower support 61. The mount-support assembly 58 includes a mount-pin support 70 and a mount pin 71. The mount-pin support is slidably mounted in the lower support 61. The lower end of the mount-pin support 70 slides on a vertically displaced track (not shown) during indexing of the sealing unit 23.

An exhaust-tubulation lock 59 is mounted on the mount-support assembly 58. The tubulation lock 59 includes three jaws and means for operating the jaws for equal movement thereof.

The main sealing unit 23 also includes means attached thereto for adjusting the rotational orientation of the mount assembly 22 and the major axis XX of the bulb assembly 21 prior to the insertion of the mount assembly 22 in the neck portion 29 of the bulb assembly 21. The adjusting means 72 comprises a movable support frame 73, an alignment member 74, a gauging unit 75, and actuating means 76 (schematically shown in FIG. 3). The alignment member 74 includes one V- shaped surface 77 and one flat surface 78. The gauging unit 75 includes two gauges 79 attached to the alignment member 74 and a comparator unit 80.

The alignment member 74 is constructed to contact the two vertical rods 63 when in measurement position. The two gauges 79 are mounted on the alignment member 74 on axes normal to a plane parallel to the vertical rods and centered on the central longitudinal axis A-A of the head assembly 54 as established by the engagement of the V-shaped surface 77 with one of the vertical rods 63. In the preferred main sealing unit 23, the vertical rod spacing 81 is 4.500 inches. The normal line 82 perpendicular to the plane of the rods is a distance 81a of 2.250 inches from the center of the V- shaped surface 77. The gauges 79 are mounted a distance 83 apart of 0.562 inch and a distance 83a of 0.281 inch from the normal line 83. The normal line 83 passes through the central longitudinal axis AA of the head assembly 54.

The rotatable head assembly 54 is initially aligned with an alignment gauge (not shown) to center the central longitudinal axis A A of the head assembly respectively on each of the mount pin 71, the two vertical support rods 63, the neck chuck 57 and the bulbalignment assembly 56. The alignment gauge is also used to establish the location of the reference surfaces 60a, 60b and 600 to rotationally position the major axis XX parallel to the two support rods 63.

THE NOVEL METHOD A bulb assembly 21 is positioned in the head assembly 54 on a bulb-support assembly 55 adapted to hold and orient the bulb assembly 21 with respect to the major and/or minor axes of the faceplate-panel portion 27. The reference surfaces 30a, 30b, and 300 are engaged with the

reference units

66a, 66b and 660 respectively, and the bulb clamp assembly 67 and the neck chuck 57 are operated to position the central longitudinal axis AA of the bulb assembly 21 coincident with the central longitudinal axis A A of the head assembly 54.

The position of the bulb assembly 21 in the head assembly 54 establishes a reference plane 84 containing the longitudinal central axis AA of the bulb assembly 21, the plane of the two support rods 63, the major axis X-X, and the central longitudinal axis A A of the head assembly 54.

A mount assembly 22 is then positioned on a mount support assembly 58 adapted to hold and orient the mount assembly 22 with the central longitudinal axis A,A of the mount assembly 22 coincident with the central longitudinal axis A-A of the bulb assembly 21 and central longitudinal axis A -A of the head assembly 54. The mount assembly 22 is positioned on the mount pin 71 with the bottom of the stem 37 substantially in full surface contact (not tilted) with the top surface of the mount pin 71. The exhaust tubulation 38 and the stem leads 39 are engaged within the mount pin 71 to substantially center the central longitudinal axis A A, of the mount assembly 22 coincident with the central longitudinal axis A A of the head assembly 54, and consequently coincident with the central longitudinal axis A--A of the bulb assembly 21.

An orientation plane 85 is then defined with respect to the structure of the in-line electron-gun assembly 36. The orientation plane 85 is at a prescribed angle with the reference plane 84. The reference plane 84 is-defined to pass through the apertures of at least two electron guns 40 and is parallel with the central longitudinal axis A,-A, of the mount assembly 22. For an inline electron-gun assembly 36, it is preferred that the orientation plane 85 is parallel to the reference plane 84.

In the mount assembly 22, the orientation plane 85 is defined by selecting two points 86a and 86b on the multiple in-line electron-gun structure. The two points are spaced from each other and radially spaced around the central longitudinal axis A,--A of the mount assembly 22. The two points 86a and 86b are an equal distance from the reference plane 84 and an equal radial distance from the aperture of the center in-line electron gun. In the in-line electron-gun assembly 36 previously described, the two points 86a and 86b are each on a line substantially normal to the reference plane 84 and located at the exterior surface of the upper G3 cup 49b. Since two of the G3 exterior surfaces are formed substantially parallel to the reference plane 84 as previously described, each of these surfaces contains the two reference points which define the orientation plane 85.

The bulb assembly 21 and the mount assembly 22 are rotated with respect to each other on the coincident central longitudinal axes A-A and A A, respectively until the orientation plane 85 is substantially parallel to the major axes.

The mount assembly 22 is first manually rotated until the reference plane of the three in-line electron guns is nearly aligned with the two vertical rods 63, the blue electron gun is on the left, and the reference surfaces 30b and 300 are behind the central longitudinal axis A-A of the bulb assembly 21. The alignment means 72 is then operated to engage the alignment member 74 with the two vertical rods 63, and to move the two gauges 79 into contact with the flat surface of the upper G3 cup 49b. The gauges 79 each contact the upper G3 cup 49b at one of the two points 86a and 86b previously described.

At this time, the mount assembly 22 is not precisely at the desired rotational alignment. The readings of the two gauges 79 on a comparator 80 will disclose any rotational misalignment. The two gauges 79 each measure the actual dimension between the reference plane 84 and one of the two points 86a or 86b on the in-line electron-gun assembly 36. The comparator 80 permits balancing or equalizing of the two measured dimensions by rotating the electron-gun assembly 22, thereby determining when the orientation plane 85 defined by the two contact points 86a and 86b is aligned parallel to the reference plane 84. The mount assembly 22 is then rotated until the measurements determined by the comparator for the two gauges 79 are equal. This occurs when the two points 86a and 86b are each an equal distance from the reference plane 84. With the two points 86a and 86b an equal distance from the reference plane 84, the reference plane 84 is parallel to the major axis XX within less than 05 of rotation about the coincident central longitudinal axes.

The mount assembly 22 is then maintained in the rotationally aligned position by closing the tubulation lock 59. Closing the tubulation lock 59 clamps the tubulation with respect to the mount pin 71 and the central longitudinal axis A A of the head assembly 54. The alignment means 72 is then retracted to a standby position.

The mount assembly 22 is then moved along the central longitudinal axis A -A of the head assembly 54 to a desired longitudinal location with respect to the faceplate portion 27 of the bulb assembly 21. The mount assembly 22 is guided within the neck portion 29 by bulb spacers 48 which substantially maintain the center of the in-line electron-gun assembly on the central longitudinal axis A-A of the bulb assembly 21. At the desired longitudinal location, the stem 37 is sealed within the neck portion 29. The mount assembly 22 is moved into the neck portion 29 during the cycle of the sealing machine 23 by the vertically displaced track previously described.

Finally,.the bulb assembly 21 and the mount assembly 22 are permanently fixed together. It is preferred that they are fixed by a seal between the stem 37 and the neck portion 29. During the sealing, the lower part of the neck portion 29, known as the collet, is removed. The sealing of the bulb assembly 21 and the mount assembly 22 also includes preheating and annealing of the glass, as is well known.

GENERAL CONSIDERATIONS AND ALTERNATIVES The novel method describes that the preferred location of the in-line electron-gun assembly is parallel to the major axis XX. The position may also be parallel to the minor axis YY or at any angle between. This may be accomplished with the novel method with the two vertical rods 63 rotated or any angle between 0 and 90 with respect to the bulb-alignment assembly.

Although the method describes positioning an inline electron-gun assembly having common electrodes, the novel method also may be used for other multiple electron-gun assemblies having separate individual electrodes for each gun. For example, the novel method may be used on an in-line or delta electron gun having individual cylindrical electrodes.

Where a mount assembly having three individual cylindrical in-line electron guns is used, the two points which define the orientation plane for the electron-gun structure are each chosen to be at the point of tangency on each electron gun of a line tangent to at least two electron guns. It is preferred that the tangent points are selected with one point on each of the two end in-line electron guns. The cylindrical electrodes must be round and concentric with the electron-gun aperture to permit the use of the novel method. Other gauging surfaces may also be selected or formed on the electrongun structure with the surfaces being precisely positioned a known dimension from the reference plane and the central longitudinal axis A A of the mount assembly 22 to establish an orientation plane parallel or coincident with a first plane through the apertures of the electron guns.

Where a delta electron-gun assembly 88 (shown in FIG. 5) having three cylindrical electron guns surrounding the theoretical center of the mount assembly at separation isused, the two points are the points of

tangency

89a and 89b on each of the two individual electron guns. For the delta electron-gun assembly 88, it is preferred that the blue gun be at the top or bottom of the viewing-screen structure. The tangent line 90 defining the orientation plane 91 then contacts the red and green individual electron-gun structure, and a reference plane 92 is defined by the apertures of the individual red and green electron guns. For a delta electron-gun assembly 88, the reference plane 92 is not coincident with the plane of the major axis XX and the two vertical rods 63 as in the in-line electron-gun assembly 36 previously described, but is parallel to the plane of the major axis XX and the vertical rods 63. Where the diameters of the two electron guns are different, the orientation plane 91 is tangent to the two electron guns and at a known angle with respect to the reference plane 92 through the apertures of the two electron guns.

The multiple-head main sealing machine is described only as the preferred apparatus for practicing the novel method. The novel method may also be practiced on a single-head sealing machine. Also, in either apparatus, the head may be held stationary and the tires rotated to make the mount-bulb seal.

We claim:

1. A method of assembling a cathode-ray tube, said tube including a bulb assembly and a mount assembly, said bulb assembly having a central longitudinal axis and including a substantially rectangularly-shaped faceplate panel having transverse major and minor axes, said mount assembly having a central longitudinal axis and including a multibeam electron-gun assembly, said method comprising the steps of a. positioning said bulb assembly in a predetermined orientation,

b. positioning said mount assembly in a location spaced from said bulb assembly with the central longitudinal axis thereof coincident with said central longitudinal axis of said bulb,

c. sensing the rotational position of said electron-gun assembly about said coincident longitudinal axes with respect to said positioned bulb assembly,

d. rotating said mount assembly about said coincident longitudinal axes until said electron-gun assembly is at a prescribed rotational orientation with respect to said bulb assembly,

e. then, while maintaining said rotational orientation,

moving said mount assembly along said longitudinal axis to a desired longitudinal location with respect to the faceplate panel of said bulb,

f. and then permanently fixing said mount assembly to said bulb assembly.

2. The method defined in claim 1 wherein said step of defining an orientation plane comprises selecting two points on the structure of the electron-gun assembly, each of said points spaced from each other and radially spaced around said central longitudinal axis of said mount assembly.

3. The method defined in claim 2 wherein said electron-gun assembly comprises three in-line electron guns, said electron guns including at least one common grid, said step comprising locating at least one pair of spaced points on said common grid, each of said points being equally distant from said reference plane through the centers of said electron guns and of equal radial distance from the central electron gun.

4. The method defined in claim 2 wherein said electron-gun assembly comprises three electron guns, each of said electron guns having at least one cylindrical electrode, said step (c) comprising locating two points on an orientation plane tangent to two cylindrical electrodes, each of said two points being on one cylindrical electrode of a different electron gun.

5. The method defined in claim 3 wherein step ((1) comprises rotating said mount assembly until said two points are each an equal distance from a plane of said coincident central longitudinal axes and one of said major or minor axes.

6. The method defined in claim 2 wherein said reference plane of said in-line electron-gun assembly is parallel to one of said major or minor axes within less than 05 of rotation about said coincident central longitudinal axes.

7. The method defined in claim 1 wherein said tube includes a phosphor line screen and electron-gun assembly having three electron guns, said phosphor lines being substantially parallel to one of said major or minor axes, said step ((1) comprising rotating said inline gun to a rotational orientation whereby said reference plane is parallel to one of said major or minor axes.

8. The method defined in claim 1 wherein maintain ing said rotational orientation comprises clamping the exhaust tubulation of said mount assembly with respect to said central longitudinal axis of said mount assembly.

9. A method of assembling a color television picture tube, said tube including a bulb assembly having a central longitudinal axis, a rectangular-faceplate panel having a major and a minor axis, and a neck portion; and a mount assembly having a central longitudinal axis and including a multibeam electron-gun assembly and a stem assembly, said method comprising the steps of a. positioning a bulb assembly on a bulb support adapted to hold said bulb in a predetermined orientation with respect to the central longitudinal axis thereof and one of the major or minor axes thereof,

b. positioning said mount assembly on a rotatable mount support adapted to hold said mount assembly with the central longitudinal axis of said mount assembly coincident with said lingitudinal axis of said bulb assembly,

0. moving an alignment means into contact with said bulb support to orient said alignment means with respect to a plane through said longitudinal axis of said bulb assembly and one of said major or minor axes,

d. sensing two preselected, spaced points on the structure of said electron-gun assembly, said points defining an orientation plane that is at a prescribed angle with a reference plane that passes through the apertures of at least two electron guns and is parallel to the central longitudinal axis of said mount assembly,

e. comparing the dimensions from said alignment means to each of said two spaced points on said electron-gun assembly,

f. rotating said mount assembly in said mount support until each of said measured dimensions is a desired dimension, whereby said reference plane through said electron-gun apertures is substantially parallel to one of said major or minor axes,

g. then, while maintaining said rotational orientation and coincident longitudinal axes, axially moving said mount assembly into said bulb assembly until the stem assembly is in the desired longitudinal position with respect to said faceplate panel,

h. and then sealing said stem assembly and said neck to form a color television picture tube assembly.

UNITED STATES PATENT OFFICE @ETIFKQAT @F PATENTNO. 3 07 00 DATED 1 April 30, 1974 INVENTOFHS) Jacob Francis Segro et: al

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, Line 58 change "ahaped" to -shaped.

Column 9, Line 26 change "'of defining an orientation plane" to (c)-;

Line 36 change "said" to a;

Line 48 change "of" to -through-;

Line 51 change '2 to 3-;

Line 56 change "1" to -3.

Column 10, Line 28 change "lingitudinal" to longitudinal-.

an flalfid this A ttest:

RUTH C. MASON C. MARSHALL DANN Alu'sling Officer (mnmissivm'r uj'lalenls and Trademarks

Claims

1. A method of assembling a cathode-ray tube, said tube including a bulb assembly and a mount assembly, said bulb assembly having a central longitudinal axis and including a substantially rectangularly-shaped faceplate panel having transverse major and minor axes, said mount assembly having a central longitudinal axis and including a multibeam electron-gun assembly, said method comprising the steps of a. positioning said bulb assembly in a predetermined orientation, b. positioning said mount assembly in a location spaced from said bulb assembly with the central longitudinal axis thereof coincident with said central longitudinal axis of said bulb, c. sensing the rotational position of said electron-gun assembly about said coincident longitudinal axes with respect to said positioned bulb assembly, d. rotating said mount assembly about said coincident longitudinal axes until said electron-gun assembly is at a prescribed rotational orientation with respect to said bulb assembly, e. then, while maintaining said rotational orientation, moving said mount assembly along said longitudinal axis to a desired longitudinal location with respect to the faceplate panel of said bulb, f. and then permanently fixing said mount assembly to said bulb assembly.

3. The method defined in claim 2 wherein said electron-gun assembly comprises three in-line electron guns, said electron guns including at least one common grid, said step (c) comprising locating at least one pair of spaced points on said common grid, each of said points being equally distant from said reference plane through the centers of said electron guns and of equal radial distance from the central electron gun.

5. The method defined in claim 3 wherein step (d) comprises rotating said mount assembly until said two points are each an equal distance from a plane of said coincident central longitudinal axes and one of said major or minor axes.

6. The method defined in claim 2 wherein said reference plane of said in-line electron-gun assembly is parallel to one of said major or minor axes within less than 0.5* of rotation about said coincident central longitudinal axes.

7. The method defined in claim 1 wherein said tube includes a phosphor line screen and electron-gun assembly having three electron guns, said phosphor lines being substantially parallel to one of said major or minor axes, said step (d) comprising rotating said in-line gun to a rotational orientation whereby said reference plane is parallel to one of said mAjor or minor axes.

8. The method defined in claim 1 wherein maintaining said rotational orientation comprises clamping the exhaust tubulation of said mount assembly with respect to said central longitudinal axis of said mount assembly.

9. A method of assembling a color television picture tube, said tube including a bulb assembly having a central longitudinal axis, a rectangular-faceplate panel having a major and a minor axis, and a neck portion; and a mount assembly having a central longitudinal axis and including a multibeam electron-gun assembly and a stem assembly, said method comprising the steps of a. positioning a bulb assembly on a bulb support adapted to hold said bulb in a predetermined orientation with respect to the central longitudinal axis thereof and one of the major or minor axes thereof, b. positioning said mount assembly on a rotatable mount support adapted to hold said mount assembly with the central longitudinal axis of said mount assembly coincident with said lingitudinal axis of said bulb assembly, c. moving an alignment means into contact with said bulb support to orient said alignment means with respect to a plane through said longitudinal axis of said bulb assembly and one of said major or minor axes, d. sensing two preselected, spaced points on the structure of said electron-gun assembly, said points defining an orientation plane that is at a prescribed angle with a reference plane that passes through the apertures of at least two electron guns and is parallel to the central longitudinal axis of said mount assembly, e. comparing the dimensions from said alignment means to each of said two spaced points on said electron-gun assembly, f. rotating said mount assembly in said mount support until each of said measured dimensions is a desired dimension, whereby said reference plane through said electron-gun apertures is substantially parallel to one of said major or minor axes, g. then, while maintaining said rotational orientation and coincident longitudinal axes, axially moving said mount assembly into said bulb assembly until the stem assembly is in the desired longitudinal position with respect to said faceplate panel, h. and then sealing said stem assembly and said neck to form a color television picture tube assembly.