US3305807A

US3305807A - Convergence apparatus with convergence members on opposite surfaces of flat members

Info

Publication number: US3305807A
Application number: US469161A
Authority: US
Inventors: Robert B Ashley; Raymond S Joseph; James V Vaccaro
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1965-07-02
Filing date: 1965-07-02
Publication date: 1967-02-21
Anticipated expiration: 1984-02-21
Also published as: DE1279068B; NL6609206A; GB1147218A

Description

Feb. 21, 1967 5, ASHLEY ET AL. 3,305,807

CONVERGENCE APPARATUS WITH CONVERGENCE MEMBERS ON OPPOSITE SURFACES OF FLAT MEMBER 2 Sheets-Sheet 1 Filed July 2, 1965 INVENTORS: ROBERT B. ASHLEY, RAYMOND S. JOSEPH, JAMES V. VACCARO, BY

THEIR ATTORNEY.

3,305,807 BERS 2 Sheets-Sheet 2 TUS WITH CONVERGENCE MEM SURFACES OF FLAT MEMBER R. B. ASHLEY ET AL APPARA ON OPPOSITE CONVERGENCE Eli].

Feb. 21, 1967 Filed July 2, 1965 INVENTORS: ROBERT B. ASHLEY, RAYMOND S. JOSEPH JAM ES V. VACCARO, BY 7 5%? I THEIR ATTORNEY.

United States Patent CONVERGENCE APPARATUS WITH CONVER- GEN CE MEMBERS 0N OPPOSITE SURFACES OF FLAT MEMBERS Robert E. Ashley, Raymond S. Joseph, and James Vaccaro, Syracuse, N.Y., assignors to General Electric Company, a corporation of New York Filed July 2, 1965, Ser. No. 469,161 Claims. (Cl. 335-210) The present invention relates to apparatus for controlling the electron beams of cathode ray tubes and more specifically to an apparatus for controlling the convergence of the various electron beams in a color cathode ray tube.

It is necessary in color cathode ray tubes of the multibeam type to effect convergence of the various electron beams at the appropriate points of the aperture mask. In this regard magnetic core members have been commonly employed to achieve static convergence of the various beams, suitable windings also being positioned on the core members to provide dynamic convergence.

More specifically, where in-line electron guns and thus linearly arrayed electron beams are employed a pair of generally U shaped core members can be utilized to effect horizontal convergence, suitable means for adjustment being provided and coils being wound on the arms of each U shaped core member to provide horizontal size correction. Similarly, a pair of generally E shaped core members can be employed to achieve vertical convergence, suitable means for adjustment again being provided and a coil being wound on the central arm of each E shaped core member to achieve vertical size correction.

The prior art convergence assemblies in general have been both complex and expensive and in many instances did not afford the requisite ease of adjustment. Further, the prior art assemblies have required special fabrication techniques and have not been compatible with the use of standard mass production techniques. Indeed, no suit able convergence assemblies whatsoever have been available for positioning the core members in the desired relationship to the various electron beams of an in-line gun tube.

Accordingly, an object of the invention is to provide an improved convergence assembly for use with a cathode ray tube employing multiple electron beams.

Another object is to provide an improved convergence assembly which employs a minimum number of elements and which is less complex than prior art devices.

Yet another object is to provide an improved convergence assembly which is less expensive than prior art devices.

A further object is to provide an improved convergence assembly which may be fabricated through the use of standard mass production techniques.

Still another object is to provide an improved convergence assembly which is easily and exactly adjustable to achieve the requisite convergence.

Yet another object is to provide an improved convergence assembly suitable for use with a color cathode ray tube employing plural linearly arrayed electron beams.

These and other objects are achieved in one embodiment of the invention through the use of a molded convergence assembly comprising a generally cylindrical support member adapted to receive the neck of the cathode ray tube, the generally cylindrical member including integral spring portions which provide an interference fit between the generally cylindrical member and the tube neck. A generally fiat body member is formed integrally with the generally cylindrical member and extends generally transverse with respect thereto.

A pair of E shaped magnetic core members are Patented Feb. 21, 1967 mounted on one surface of the body portion, the E shaped magnetic core members being positioned on opposite sides of the generally cylindrical member in diametrical opposition with each other. The body portion is provided with a suitable receptacle for the E shaped core members and includes integrally formed spring fingers for retaining the core members in the desired position.

A pair of generally U shaped magnetic core members are slideably mounted on the opposite surface of the generally fiat body member in a position similar to that of the E shaped core members. Each of the U shaped core members is mounted to an adjustable slide member, the slide member being molded and including integrally formed spring fingers for retaining the U shaped core in the desired position and for biasing the slide against the body member.

The novel and distinctive features of the invention are set forth in the appended claims. The invention itself together with further objects and advantages thereof, may best be understood by reference to the accompanying drawings in which:

FIGURE 1 is a partially exploded perspective view of the convergence assembly of the invention,

FIGURE 2 is a front view of the convergence assembly shown in FIGURE 1,

FIGURE 3 is a back view of the assembly shown in FIGURE 1, and

FIGURE 4 is a top view of the assembly shown in FIGURE 1.

Referring to the partially exploded view of FIGURE 1, the convergnece apparatus of the invention comprises an integrally molded support assembly including a generally cylindrical member 1 adapted to engage the neck of a cathode ray tube and a generally flat body member 3 extending transversely from the member 1. A pair of molded slide assemblies 5 are provided for slideably mounting suitable core members to the support assembly. In accordance with an important feature of the invention the support assembly and slide assemblies are easily fabricated by injection molding of a suitable plastic material such as polypropylene.

The generally cylindrical member 1 comprises first and second portions 7 and 8 respectively, the portions 7 and 8 being joined by a pair of intermediate integral spring loop portions 9. The generally cylindrical member 1 further includes suitable apertures 11 for receiving the ends of the associated core members. A plurality of longitudinally extending fingers 13 are provided as shown more clearly in FIGURE 4, a circular clamp being placed ove1r( these fingers to rigidly afiix the apparatus to the tube nec The generally flat body member 3 includes two essentially identical portions extending from opposite sides of the cylindrical member 1 and formed integrally therewith. For purposes of simplicity, similar elements on each side of the generally cylindrical member 1 are given identical reference numerals. Each portion of the generally fiat body member 3 is provided with a deck portion 14 having a pair of side rails 15 formed integrally therewith and at right angles thereto. Each side rail 15 is provided with a lip 17 to thereby define a pair of tracks for slideably receiving the slide assembly 5. A pair of integral outwardly extending spring members 19 are provided on the deck portion 14, as shown more clearly in FIGURE 3, the spring members 19 having a pair of apertures 21 associated therewith and serving to maintain the associated core members in the desired position.

Each portion of the body member 3 is provided with a suitable terminal board 23 having electrical terminals 25 associated therewith to which may be connected the leads of the various coils which are associated with the magnetic core members. In addition each deck portion 14 of the body member 3 is provided with a screw receiving boss 27 having a hole 28 therein for mounting the slide assembly in the desired position.

Identical slide assemblies 5 are positioned on opposite sides of the generally cylindrical member 1, the corresponding elements of each slide assembly being given identical numerals. For the purposes of clarity, one of the slide assemblies 5 is shown removed from the body member 3 while the remaining slide assembly 5 is shown partially inserted in the tracks defined by side rails and the associated lips .17.

Each slide assembly 5 comprises a fl'at body member 29 having a pair of rails 31 formed on the under surface thereof. The flat body member 29 is provided with a plurality of outwardly extending integral spring fingers 33 at the side edges thereof, the spring fingers 33 being adapted to engage the under surface of the lip 17 to spring bias the rails 31 against the deck portion -14.

The slide assembly 5 is adapted to receive and retain a U shaped core member generally shown at 35 by the provision of a plurality of outwardly extending positioning tabs 37 and a pair of integrally formed spring members 39 having apertures 40 associated therewith. An elongated slot 41 is provided for receiving a suitable screw 43, the screw in turn being received by the hole 28 of boss 27. In this manner the slide assembly 5 is adjustable along the tracks defined by side rails 15 and the associated lips 17 to an extent determined by the length of the slot 41 in order to control the convergence of the various beams. A pair of outwardly extending finger tabs 45 are further provided to facilitate adjustment of the slide assembly 5 along the tracks.

The U shaped core member 35 comprises first and second L shaped

portions

47 and 49 respectively and a ferrite magnet 51 rotatably positioned therebetween. The surfaces of

core portions

47 and 49 abutting the magnet '51 are slotted at 52 and "53 respectively to rotatably receive the magnet 51. The magnet 51 is polarized across its diameter so that rotation of the magnet 51 between the

core portions

47 and 49 controls the magnitude and direction of the magnetic flux traversing the ends of the core portions to thereby provide a finer control of convergence than is easily achieved by adjusting the slide assembly 5 alone. 7

The U shaped core is positioned on the slide assembly 5 between the various outwardly extending positioning tabs 37, the

core portions

47 and 49 with the magnet 51 therebetween being retained bet-wen the positioning tabs 1 37 by the action of the integral spring fingers 39 in exerting opposing forces thereon. With the U shaped core 35 assembled to the slide assembly 5 in this manner, the top portions of certain of the positioning tabs 37 may be deformed by heat to lock the U shaped core 35 in place. As an alternative cement or wax might be employed to lock theU shaped core 35 to the slide assembly 5 and to maintain the magnet 51 in the desired angular position with respect to the

core portions

47 and 49 after convergence is achieved.

Referring to FIGURE 2, there is shown a front view of the assembly of FIGURE 1 with both slide assemblies 5 in place and the entire convergence assembly positioned on the neck 54 of a cathode ray tube having a plurality of linearly arrayed electron beams 55 passing therethrough. For purposes of simplicity, the pole pieces internal to the tube neck 54 have been omitted; however, it will be appreciated that such internal pole. pieces would normally'be employed to complete the various magnetic circuits and achieve the necessary convergence.

tions 7 and 8 are overlapped so that the distance across The convergence assembly of the invention is retained on the, tube neck by an interference fit between the portions 7 and 8 of the generally cylindrical member 1. In order to achieve the interference fit the radii of the portions 7 and 8 are chosen to be equal to the maximum radius to be encountered within the tolerances of the tube neck. However, the centers of the radii defining pordiameter to be encountered within the tolerances of the tube neck. Thus, the intermediate integral spring loop portions 9 bias the portions 7 and 8 toward each other so that an interference fit exists between these portions and the tube neck 54. It will be appreciated that, due to the presence of the spring loop portions 9, the assembly of the invention is easily assembled to the neck of the tube by sliding the assembly along the neck to the desired position, the aforementioned interference fit subsequently maintaining the assembly in the desired position.

The slide assemblies 5 are shown assembled to the deck portion 14 by the screw 43 passing through the slots 41 and being received by the holes 28 in bosses 27. In this manner, the position of the U shaped core 35 with respect to the electron beams 55 can be changed by loosening the screws 43 and slid-ing the slide assembly 5 in the desired direction, the ends of the U shaped core 35 being received by the apertures 11 in the cylindrical member 1 at the extreme of the travel of slide 5 to allow the U shaped cores 35 to be brought into close proximity to the various electron beams. Similarly, the angular position of the magnets 51 with respect to the

core members

47 and 49 can be varied to control the flux to thereby allow fine adjustment to achieve the necessary horizontal convergence.

Additionally, windings 5 7 are positioned on the arms of the U shaped core 35 to provide for horizontal size correction. Suitable connections (not shown) are made between the windings 57 and the appropriate terminals 25.

Referring to FIGURE 3 there is shown a rear view of the convergence assembly of FIGURE 1 showing the positioning of a pair of vertical convergence controlling E *shaped core members 58 at opposite sides ofthe gen} manner to the magnet 51. A winding 65 is positioned on each central arm 61 to provide for vertical size correction, connections (not shown) being utilized to connect 'each winding 65 to the appropriate terminals 25.

An integral receptacle generally shown at 66 is pro vided on the deck portion 14 for each E shaped core member 58. Each receptacle 66 comprises "an end wall portion 67 and a pair of side wall portions 69. In addition, outwardly extending locating tabs 71 are provided for accurately positioning the E shaped core members. The integral spring fingers 21 serve to bias the U shaped member 59 against the central arm 61 with the ferrite magnet 6-3 interposed therebetween and to maintain the E shaped core member in the desired position. The ends of the E shaped core in this position are interposed in the spaces between adjacent one-s of the longitudinally extending fingers 13 so that proximity between the E shaped core and the various electron beams is assured;

In addition, as with the U shaped core members 35, certain of the elements of the receptacle 66' can be deformed to rigidly fix the E shaped core in the desired position or cement or wax might be employed for this purpose. Again,.as with the ferrite magnets 51, the ferrite magnets 63 can be rotated to control the magnitude of the flux :and thus the convergence of the various beams. It is found that the provision of the magnet 63 in this manner is suflicient to effect vertical convergence in nearly all situations so. that a slide is not necessary as is the case for horizontal convergence. However, in

. some applications it might 'be necessary to employ a slide for the E shaped core members 58 similar to slide assembly 5.

Referring to FIGURE 4, there is shown a top view of the convergence assembly of the invention as positioned on the neck 54 of the cathode ray tube. As shown, a circular clamp 73 is utilized to encircle the longitudinally extending fingers 13 to rigidly afiix the assembly to the tube neck.

Although the invention has been described with respect to certain specific embodiments, it will be appreciated that modifications and changes may be made by those skilled in the art Without departing from the true spirit and scope of the invention. In particular, although the depicted embodiment of the invention has been directed toward use with a cathode ray tube employing in-line guns, it will be appreciated that the depicted device might be easily modified for use with the more conventional triad gun tube.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An electron beam convengence apparatus for use with a cathode ray tube including a neck traversed by a plurality of electron beams, said apparatus comprising;

(a) a generally cylindrical member adapted to encircle the neck of the cathode ray tube in engagement there with,

(b) a generally fiat body member integral with said generally cylindrical member and extending generally transverse thereto,

, (c) a plurality of magnetic core members mounted to opposite surfaces of said body member and arranged about said cylindrical member in spaced relationship one with the other to control the convergence of the electron beams.

2. The convergence apparatus defined in claim 1 wherein said generally cylindrical member includes an integral spring loop portion for biasing said generally cylindrical member against the neck of the cathode ray tube.

3. The convergence apparatus defined in claim 1 wherein said generally cylindrical member includes first and second semicylindrical portions having first and second integral spring loop portions therebetween.

4. The convergence apparatus defined in claim 3 wherein the radius of each of said semi-cylindrical portions is substantially equal to the maximum radius of the tube neck Within the tolerances thereof and the centers of the radii of each semi-cylindrical portion are overlapped so that the distance betwen said semi-cylindrical portions through said centers is less than the minimum diameter of the tube neck within the tolerances thereof.

5. The convergence apparatus defined in claim 1 wherein said generally cylindrical member is provided with a plurality of axially extending fingers adapted to be clamped to the tube neck to rigidly mount said convergence apparatus thereto,

6. An electron beam convergence apparatus for use with a cathode ray tube including a neck traversed by a plurality of linearly arrayed electron beams, said apparatus comprising;

(a) a generally cylindrical member adapted to encircle the neck of the cathode ray tube in engagement therewith,

(b) a generally fiat body member integral with said generally cylindrical member and extending gener-ally transverse thereto,

(c) first and second generally E shaped magnetic cores,

each comprising first and second core elements having a permanent magnet interposed therebetween.

(d) said first and second generally E shaped magnetic cores, being disposed in diametrically opposed relationship with respect to said generally cylindrical member and being mounted to a first surface of said body member, and

(e) first and second generally U shaped magnetic cores, each comprising first and second core elements having a permanent magnet interposed therebetween,

(f) said first and second generally U shaped magnetic cores being disposed in diametrically opposed relationship with respect to said generally cylindrical member and being slideably mounted to the surface of said body member opposite said first surface.

7. The convergence apparatus defined in claim 6 wherein said body member includes first and second slide assemblies having said first and second U shaped cores respectively positioned thereon and said body member further includes channel members adapted to slideably receive said slide assemblies.

8. The convengence apparatus defined in claim 7 wherein each of said slide assemblies includes a plurality of integral spring fingers engaging said channel members to bias the slide assembly against said body member.

9. The convergence apparatus defined in claim 7 wherein each of said slide assemblies includes a plurality of integral spring members ena ging the first and second core elements of the associated U shaped core to exert retaining forces thereon.

10. The convergence apparatus defined in claim 6 wherein said first surface of said body member is provided With a plurality of integral spring members engaging the first and second core elements of the associated E shaped cores to exert retaining forces thereon.

No references cited.

JAMES W. LAWRENCE, Primary Examiner. R. SEGAL, Assistant Examiner,

Claims

1. AN ELECTRON BEAM CONVERGENCE APPARATUS FOR USE WITH A CATHODE RAY TUBE INCLUDING A NECK TRAVERSED BY A PLURALITY OF ELECTRON BEAMS, SAID APPARATUS COMPRISING; (A) A GENERALLY CYLINDRICAL MEMBER ADAPTED TO ENCIRCLE THE NECK OF THE CATHODE RAY TUBE IN ENGAGEMENT THEREWITH, (B) A GENERALLY FLAT BODY MEMBER INTEGRAL WITH SAID GENERALLY CYLINDRICAL MEMBER AND EXTENDING GENERALLY TRANSVERSE THERETO, (C) A PLURALITY OF MAGNETIC CORE MEMBERS MOUNTED TO OPPOSITE SURFACES OF SAID BODY MEMBER AND ARRANGED ABOUT SAID CYLINDRIAL MEMBER IN SPACED RELATIONSHIP ONE WITH THE OTHER TO CONTROL THE CONVERGENCE OF THE ELECTRON BEAMS.