US3631902A

US3631902A - Deflection system for triad-beam cathode-ray tube

Info

Publication number: US3631902A
Application number: US841782A
Authority: US
Inventors: Charles Edward Torsch
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1969-07-15
Filing date: 1969-07-15
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04
Also published as: US3643125A; DE2035082A1; GB1324412A; GB1324413A; GB1324414A; FR2051764A1; FR2051764B1; DE7026618U; CA961543A; CA945267A; BE753426A

Abstract

A cathode-ray tube deflection system includes a triad-type cathode-ray tube and a torrid-type deflection yoke having horizontal and vertical axes with first and second horizontal windings symmetrical to the horizontal axis in mirror image of one another about the vertical axis and first and second vertical winding symmetrical to the vertical axis in mirror image of one another about the horizontal axis and said first and second horizontal and vertical windings each including a flux-altering means for enhancing vertical convergence of horizontal trace lines. The deflection yoke is formed by a process wherein a core of magnetic material is wrapped with wire turns applied in toroidal fashion to form first and second horizontal windings and first and second vertical windings advanced in opposite circumferential direction to form a mirror-image relationship. Also, ''''ringing'''' is inhibited by circuitry wherein a specific terminal of each of the horizontal and the vertical windings associated with the start of electron beam scanning of the cathode-ray tube is connected to a potential reference level while the other extremities of the horizontal and vertical windings are connected to a source of deflection signals whereby undesired distortions appearing on the trace lines of the viewing screen are minimized.

Description

Waited States Patent [72] Inventor Charles Edward Torsch Rochester, N.Y.

[21] Appl. No. 841,782 a [22] Filed July 15, 1969 [45] Patented Jan. 4, 1972 [73] Assignee Sylvania Electric Products Inc.

[5 4] DEFLECTION SYSTEM FOR TRIAD-BEAM Primary ExaminerLowell A. Larson Att0rneysNorman J. OMalley, Donald R. Castle and Thomas H. Buffton ABSTRACT: A cathode-ray tube deflection system includes a triad-type cathode-ray tube and a torrid-type deflection yoke having horizontal and vertical axes with first and second horizontal windings symmetrical to the horizontal axis in mirror image of one another about the vertical axis and first and second vertical winding symmetrical to the vertical axis in mirror image of one another about the horizontal axis and said first and second horizontal and vertical windings each including a flux-altering means for enhancing vertical convergence of horizontal trace lines. The deflection yoke is formed by a process wherein a core of magnetic material is wrapped with wire turns applied in toroidal fashion to form first and second horizontal windings and first and second vertical windings ad vanced in opposite circumferential direction to form a mirrorimage relationship. Also, ringing" is inhibited by circuitry wherein a specific terminal of each of the horizontal and the vertical windings associated with the start of electron beam scanning of the cathode-ray tube is connected to a potential reference level while the other extremities-of the horizontal and vertical windings are connected to a source of deflection signals whereby undesired distortions appearing on the trace lines of the viewing screen are minimized.

PAKNTED JAN 4 I972 SHEET 1 [IF 6 GREEN RED RED GREEN l g I 7 l I I I l I i I i fi r L n L GREEN RED RED REEN INVENTOR. CHARLES E.TORSCH ATTORNEY PAIENTEUJAN M972 SHEET 2 BF 6 INVEN'IOR. CHARLES E.TORSCH ATTORNEY PATENTEI] JM 4 E72 SHEET 3 UF 6 LEFT HORIZONTAL l INVLNTOR. CHARLES E. ORSC BOTTOM VERTICAL ATTORNEY PAIEN TED JAN 4 I972 SHEET I (IF 6 .EwUmmkZ Q3010 :00 J FZONEOI wQw FIOE ZBEMQW86 2O DEGREES FROM HORIZONTAL AXIS 90 IN VEN T0 R.

CHARLES E. TORSCH 4O 50 DEGREES FROM HORIZONTAL AXIS ATTORNEY VERTICAL COIL W GROUP INTERCEPT IATENIEIIJAI 4872 3531 902 SHEET S []F 6 I8 I I6 W I4 X 0 so so so a0 DEGREES FROM VERTICAL AXIS INVENTOR. CHARLES E.TORSCH ATTORNEY DEFLECTION SYSTEM FOR TRIAD-BEAM CATHOIDE- RAY TUBE BACKGROUND OF THE INVENTION Cathode-ray tube deflection systems normally include a cathode-ray tube and an asociated deflection yoke. The cathde-ray tube has a viewing screen which is impinged by one or more electron beams to provide a so-called scan raster and the deflection yoke creates a magnetic field of altering strength and polarity which causes the electron beam to scan the viewing screen to effect the scan raster.

In present day television receivers and especially in receivers employing a cathode-ray tube wherein the electron guns and phosphors of the viewing screen are of a triad arrangement, the most common type of deflection yoke is the so-called saddle yoke. In the saddle yoke construction, a pair of horizontal deflection windings are mounted on the top and bottom respectively of the cathode-ray tube to produce a magnetic field parallel to a vertical axis. Also, a pair of vertical deflection windings are mounted on opposite sides of the cathode-ray tube to effect a magnetic field parallel to a horizontal axis.

Although such devices have been and still are widely employed in triad-type cathode-ray tube deflection systems, it has been found that such deflection yokes do leave something to be desired. More specifically, it has been found that saddle-type deflection yokes provide electron beam deflection which is lacking in uniformity and consistency. Also, such deflection yokes employ a relatively large amount of expensive copper and ferrite materials, are relatively cumbersome and bulky, and are most difficult, if not impossible, to fabricate with uniformity.

Further, cathode-ray tube deflection systems employing the above-mentioned saddle-type deflection yokes also include a convergence system whereby a plurality of electron beams emanating from a triad-gun arrangement are converged to provide a scan raster on a viewing screen of the cathode-ray tube. Moreover, well-known pincushion correction circuitry employed in all known traid-type deflection systems is utilized to effect a substantially straight-sided raster.

Although the above-mentioned triad-type deflection systems employing a saddle yoke do leave something to be desired, the only known attempt to overcome the above-mentioned problems is the provision of a so-called in-line deflec-,

tion system. Therein, a cathode-ray tube having a plurality of electron guns arrayed in a single plane is employed with a socalled toroid" type deflection yoke.

As set forth in US. Pat. No. 2,925,542 issued to R. B. Gethmann on Feb. 16, 1960 and US. Pat. No. 3,430,099 issued to R. B. Ashley on Feb. 25, 1969, an in-line gun-type of cathode-ray tube evolves special problems which require a specific form of deflection yoke as well as a special form of convergence apparatus. As set forth therein, the deflection yoke apparatus provides a substantially straight-sided scan raster unsuitable to the normally employed convergence and pincushion circuitry common to triad-gun deflection systems, but rather adapted to size-correction apparatus foreign to triad-gun systems.

Additionally, present day NTSC color television receivers employ horizontal scanning by the electron beam at a rate of about 15,734 cycles per second with the electron beam scanning from left to right of the viewing screen, as seen by an observer, and rapidly retracing or returning to repeat the scan cycle. Also, the electron beam is advanced in a vertical direction from the top to the bottom of the cathode-ray tube at a rate of about 60 cycles per second and rapidly returned to repeat the cycle.

As is well known, the abrupt change in value of a potential applied to the deflection windings to effect the rapid retrace of the electron beam and initiation of the following scan line causes the development of oscillations or spurious ringing" in the windings of the yoke. This undesired ringing" usually continues after the scanning period of the electron beam is started and appears as an undesired intensity variation or distortion at the left-hand portion of the viewing screen raster as observed by a viewer.

In order to minimize this undesired distortion due to ringing, it has been a common practice to employ circuitry such as set forth in US. Pat. No. 2,869,030 issued to M. Deranian et al. on Jan. 13, 1959. Therein, a pair of horizontal deflection windings of the so-called saddle"-type are series-connected, a pair of series-connected capacitors of substantially equal value are shunted across the series-connected windings, a resistor couples the junction of the series-connected capacitors to the junction of the series-connected deflection windings, one of the windings is coupled to a deflection signal source and the other winding to an AC potential reference level, and a capacitor is shunt-connected across the winding coupled to the deflection signal source. Moreover, vertical saddle" windings are usually shunted by resistors to damp the capacitively coupled charge flow from the horizontal coils during and after horizontal retrace.

Obviously, the above-mentioned circuitry is complex as well as expensive in components and assembly time and skill. Moreover, the circuit complexity reduces reliability while adding undesired bulk and cost.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide an enhanced cathode-ray tube deflection system. Another object of the invention is to provide an improved deflection yoke applicable to a television receiver deflection system. Still another object of the invention is to provide an enhanced process for fabricating improved deflection yokes for cathoderay tube deflection systems. A further object of the invention is to provide an improved deflection circuit arrangement for a television receiver. A still further object of the invention is to provide an improved process for fabricating an improved deflection yoke for use in an improved deflection circuitry arrangement. Still another object of theinvention is to provide a toroidally wound deflection yoke and a deflection circuit arrangement suitable for replacement of the well-known saddle yoke and deflection circuit arrangement employed in triad-gun-type cathode-ray tube systems.

These and other objects, advantages and capabilities are achieved in one aspect of the invention by a deflection yoke having a substantially circular core of magnetic material with first and second horizontal deflection windings toroidally wound thereon in mirror image of one another and oppositely disposed about a vertical axis. The deflection yoke is fabricated by a process wherein a circular core is selected and wrapped with toroidal wire turns to provide bank-wound wire groups which are intermittently spaced along the circumference of the core to provide a winding. Also, a deflection circuit arrangement for minimizing ringing currents in a deflection yoke includes a circuit means coupling one of a pair of series-connected deflection windings associated with the start of electron beam scanning to a potential reference level and the other deflection winding to a deflection signal source.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional elevation of a cathode-ray tube and associated toroidal deflection yoke;

FIG. 2 is a screen-end view diagram of the winding distribution of the exterior wires of a toroidal yoke embodiment of the invention;

FIG. 3 is a planar view illustrating the form of a pair of horizontal windings;

FIG. 4 is an elevation view illustrating the form of a pair of vertical windings;

FIGS. 5, 6 and 7 illustrate a cathode-ray tube raster as observed by a viewer;

FIGS. 8 and 9 are graphical representations of the horizontal deflection windings;

FIG. 10 is a graphical representation of a vertical deflection winding;

FIG. 11 is an illustration, in block and schematic form, of a television receiver and associated deflection circuit arrangement for a cathode-ray tube; and

FIG. 12 is a schematic illustration of the winding of a toroidal deflection yoke and associated deflection circuit arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENT For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in conjunction with the accompanying drawings.

Referring to the drawings, FIG. 1 illustrates a typical cathode-ray tube deflection system including a triad-type cathode-ray tube 5, a deflection yoke coil 9. The cathode-ray tube 5 includes a viewing screen 11 which is impinged by one or more electron beams 13 derived from one or more electron guns 15. I

In cathode-ray tube systems wherein the cathode-ray tube 5 includes a plurality of electron beams 13 derived from a plurality of electron guns 15, a convergence coil 9 is normally disposed rearwardly, as viewed by a cathode-ray tube observer, of the viewing screen 11 and of the deflection yoke 7. This convergence coil 9 serves to effect convergence of the plurality of electron beams 13 at or near the surface of the viewing screen 1 1 of the cathode-ray tube 5.

Also, the deflection yoke 7 is afi'rxed to the cathode-ray tube 5 and located rearwardly of the viewing screen 11. This deflection yoke 7 is generally operable in a manner well known in the art to effect deflection of the electron beams 13 in both horizontal and vertical directions. Moreover, the deflection yoke 7, as employed in all known present-day television receivers, causes electron beam scanning which progresses from left to right and top to bottom of the viewing screen 11.

Further, the deflection yoke 7 is of the toroidal type having a substantially circular core 16 of a magnetic material having a relatively high-permeability factor, one hundred or more for instance, and a plurality of windings of wire turns 17 wrapped in toroidal fashion on the circular core 16. As to the wire turns 17 and toroidal windings, reference is made to the schematic illustration of FIG. 2.

In FIG. 2, a preferred wire configuration form includes a substantially circular core 16 of magnetic material supporting a plurality of toroidal-wrapped wire turns. For clarity, only those turns in abutting relationship to the outer surface of the core 16 are illustrated. Also, a preferred wire configuration form includes at least one of such features as interlaced deflection windings, sawtoo "-wound deflection windings, mirror-image deflection windings, intermittent bank-wound deflection windings, deflection windings having a flux-altering means, intermittent bank-wound deflection windings having added turns, and deflection windings afiixed by a process which includes advancement in opposite circumferential directions. Moreover, the above-mentioned features will be explained hereinafter.

More specifically, the wire configuration of FIG. 2 includes a horizontal axis H-I-I' and a vertical axis designated V-V'. A first or left horizontal deflection winding 19, represented by blackened dots, is disposed to the left of the vertical axis V- V and a second or right horizontal deflection winding 21, represented by blackened dots, is disposed to the right of the vertical axis V-V. Moreover, the wire configuration and

windings

19 and 21 of FIG. 2 are illustrated in the same positional location as they would appear to a viewer of the display screen 11 of the cathode-ray tube 5 of FIG. 1, with the deflection yoke 7 attached thereto.

As can be seen, each of the horizontal deflection windings I9 and 21 is not only substantially symmetrical with respect to the horizontal axis HH but also in substantially mirrorimage relationship on opposite sides thereof. Moreover, each of the horizontal deflection windings l9 and 21 includes a 7, and a convergence flux-altering means 23 and 25 respectively, centrally disposed about the horizontal axis HH' which, in this instance, is illustrated as a winding gap. Obviously, short-circuited turns, shielded turns, and similar techniques for altering a flux pattern would be equally appropriate.

Also, each of the horizontal deflection windings l9 and 21 includes a plurality of wire groups or groups of wire turns in intermittent circumferential-spaced relationship about the circular core 16. Each of these groups of wire turns has a centrally located force of magnetic influence and is preferably in the form of an intermittent bank-winding wherein a first layer of turns includes at least one pair of adjacent turns and a second layer of turns includes at least one pair of adjacent turns and a second layer of turns includes a wire turn contacting and supported by the pair of adjacent turns of the first layer of turns. Should the wire group include more than a single pair of adjacent turns in the first layer of turns, the second layer of turns would include a wire turn contacting and supported by each pair of turns of the first layer.

These particular intermittent bank-wound horizontal deflection windings l9 and 21 each include added turns 27/28 and 29/30 respectively, disposed on opposite sides of the fluxaltering means 23 and 25. Moreover, these added turns 27/28 and 29/30 are preferably disposed in substantially similar but not necessarily identical circumferential-spaced relationship to the flux-altering means 23 and 25, and serve to enhance electron beam convergence, as will be explained hereinafter.

Further, the first and second horizontal deflection windings l9 and 21 are preferably, not necessarily, in complete mirrorimage relationship to one another about the vertical axis V V'. As can readily be seen in the illustrative example of FIG. 3, the first horizontal deflection winding 19 and the second horizontal deflection winding 21 are affixed in reversed progression to effect the above-described mirror-image relationship about the vertical axis V-V', as observed on the exterior surface of the core member 16.

Additionally, the above-mentioned mirror-image relationship between the first and second deflection windings is preferably, not necessarily, an identical relationship. In this specific illustration, referring back to FIG. 2, the circumferential spacing of the added turns 27 and 28 of the first deflection winding 19 with respect to the horizontal axis H- H differs from the circumferential spacing of the added turns 29 and 34) of the second deflection winding 21. Thus, the abovedescribed mirror-image relationship is effected except for this slight deviation of the added turns 27 and 28 and 29 and 30.

Interleaved with the first and second

horizontal deflection windings

19 and 21 and symmetrically disposed about the vertical axis V-V' is a first or top vertical deflection winding 31 and a bottom or second vertical deflection winding 33, both represented by white circles in the illustration of FIG. 2. Each of these

vertical deflection windings

31 and 33 is symmetrical to the vertical axis V-V' and disposed in mirror-image relationship about the horizontal axis II-H'. Also, each vertical deflection winding 31 and 33 includes a flux-altering means 35 and 37 which is also symmetrically disposed about the vertical axis V-V.

As was previously explained with respect to the

horizontal deflection windings

19 and 21, each of the

vertical deflection windings

31 and 33 is in the form of intermittent circumferentially spaced wire groups. However, the

vertical deflection windings

31 and 33 are in the form of intermittent-spaced wire groups which are electrically connected in a sawtooth manner. Therein, the first layer of turns of the total winding are serially connected and advanced in one circumferential direction. The second layer of turns is applied to the first layer and advanced in the same circumferential direction. As a result, the potential difference between adjacent turns of the first and second layers is more nearly constant.

Also, as can be readily seen in the illustrative example of FIG. 4, the first vertical deflection winding 31 and the second vertical deflection winding 33 are affixed to the core member 16 in reversed progression. in this manner, the first and second

vertical deflection windings

31 and 33 provide a mirror-image relationship with respect to one another about a horizontal axis H-H' as observed from the exterior surface of the core member 16, from either left or right side of the yoke.

Thus, there has been provided a toroid deflection yoke having interleaved first and second horizontal and first and second vertical deflection windings, l9 and 21 and 31 and 33. The

horizontal deflection windings

19 and 21 are each in vertical symmetrical relationship about the horizontal axis HH' and in substantial mirror-image relationship to one another about the vertical axis VV'. Also, each of the

horizontal deflection windings

19 and 21 is in bank-wound form and respectively includes a flux altering means 23 and 2S and added turns 27/28 and 29/30 symmetrically disposed about the horizontal axis H-H'.

Similarly, the

vertical deflection windings

31 and 33 are horizontally symmetrical about the vertical axis V-V and in mirror-image of one another about the horizontal axis 11-1-1. Moreover, the

vertical deflection windings

31 and 33 are of sawtooth-connected form and respectively include a flux-altering means 35 and 37 As to the fabrication of a toroid-type deflection yoke, a substantially circular core 16 of magnetic material having a horizontal and a vertical axis is selected. Wire turns are wrapped in toroidal fashion on opposite sides of the horizontal axis Hl-i of the core 16 and advanced in opposite circumferential directions to provide first and second

vertical deflection windings

31 and 33. Also, wire turns are wrapped in toroidal fashion on opposite sides of the vertical axis VV' of the core 16 and advanced in opposite circumferential directions to provide first and second

horizontal deflection windings

19 and 21. Moreover, the windings are circumferentially spaced such that interleaving of the vertical and horizontal windings is effected.

More specifically, a preferred process for fabricating a toroid-type deflection yoke of the type illustrated in FIG. 2 includes selecting a substantially circular core 16 of a magnetic material. Then, the first layer of turns of the

vertical deflection windings

31 and 33 are wrapped in toroidal fashion about the circular core 16. This first layer of turns includes intermittent circumferentially spaced pairs of wire turns which are advanced in opposite circumferential directions on the core 16 and disposed on opposite sides of the horizontal axis of the core 16. Thus, the first layer of turns of both the first and second

vertical deflection windings

31 and 33 define intermittent circumferential spaces along the core 16.

Following, the first and second

horizontal deflection windings

19 and 21 are applied to the core 16 in interleaved relationship with the first and second

vertical deflection windings

31 and 33. The first and second horizontal deflection windings l9 and 21 are formed by wrapping wire turns in toroidal fashion about the core 16 and affixing these toroidalwrapped wire turns to the core 16 in the intermittent circumferential spaces defined by the first layer of wire turns of the first and second

vertical deflection windings

31 and 33. Moreover, the first and second

horizontal deflection windings

19 and 21 are oppositely disposed with respect to the vertical axis V-V and are advanced in opposite circumferential directions.

in the actual application of one of the horizontal deflection.

windings

19 and 21, at least one pair of toroidal-wrapped wire turns is affixed to the core 16 within a space defined by the

vertical deflection windings

31 and 33. Then, a toroidalwrapped turn of a second layer contacts and is supported by the pair of wire turns of the first layer to provide a wire group. Also, the wire turns of the first and second layers are serially connected to minimize the potential difference therebetween which, in turn, minimizes insulation requirements.

Further, the winding then advances to the following space defined by the first layer of the

vertical deflection windings

31 and 33. Moreover, a plurality of pairs of turns may be afiixed to the core 16 with the second layer of turns including a first turn supported by the first pair of turns of the first layer and following turns advancing in the same circumferential direction as the first layer of turns with a second layer turn contacting and supported by each advancing pair of turns of the first layer.

Thus, each of the

horizontal deflection windings

19 and 21 is of the so-called bank-wound form wherein each turn of a second layer of turns is supported by a pair of turns of a first layer of turns. Also, the turns of the first and second layers of turns are advanced in the same circumferential direction. Moreover, the wire turns of the

vertical deflection windings

31 and 33 serve to confine the wire groups of the

horizontal deflection windings

19 and 21 to a restricted space preventing undesired distortion and spreading of the first layer of turns by the force exerted thereon by the second layer of turns.

Following, a second layer of toroidal-wrapped wire turns is applied to the

vertical deflection windings

31 and 33. This second layer of turns starts in the same location and advances in the same direction as the first layer of turns of each of the

vertical deflection windings

31 and 33. Also, the final turn of the first layer of turns of each of the

vertical deflection windings

31 and 33 is connected electrically to the first turn of the second layer of turns. This type connection is normally referred to as a sawtooth connection whereby the potential difierence intermediate adjacent turns of the first and second layers is substantially constant throughout the total winding.

Thus, the first and second

vertical deflection windings

31 and 33 are affixed to the core 16 by applying a first layer of spaced turns advanced in opposite circumferential direction. The first and second

horizontal deflection windings

19 and 21 are interleaved with the

vertical deflection windings

31 and 33 within the spaced provided by the first layer thereof. These

horizontal deflection windings

19 and 21 are of a bank-wound form with first and second layers of wire turns forming wire groups and the wire turns and wire groups serially connected. Then, the second layer of turns of the

vertical deflection windings

31 and 33 are applied to the first layer to form wire groups advancing in opposite circumferential directions and electrically connected in a sawtooth connection.

As to operation of a toroidal-wound deflection yoke 7 in conjunction with a triad-type cathode-ray tube 5, it may first be assumed that the flux-altering means 23 and 25 of the first and second

horizontal deflection windings

19 and 21 are omitted, as well as the flux-altering means 35 and 37 of the first and second

vertical deflection windings

31 and 33. Also, it is assumed that the added turn pairs 27/28 and 29/30 have not been included in the first and second

horizontal deflection windings

19 and 21.

Under these conditions, it was found that the observer of the viewing screen 11 of a triad-gun-type color cathode-ray tube 5 tended to see a substantially straight-sided raster, illustrated in FIG. 5. However, the raster has what is commonly referred to as a reverse red trapazoid wherein the red and green traces have opposing slopes with the separation of the green traces at a minimum to the right of the viewing screen 1 1 as observed by a viewer. Moreover, it was found that convergence of the traces of a color receiver wherein the abovementioned reverse red trapazoid is present was most dif ficult, if not impossible, with convergence circuitry normally available in present-day television receivers utilizing triadgun-type cathode-ray tubes.

Further, it was found that the inclusion of the flux-altering means 23 and 25 in the

horizontal deflection windings

19 and 21 and centered about the horizontal axis H-1-1' tended to cause what is classically described as a barrel effect or overcorrection of the magnetic flux within the toroid deflection yoke 7 of FIG. 1. This barreF effect of the magnetic flux appears as a so-called "pincushioned" raster (see FIG. 6) as seen by a viewer of the screen 11 of a color cathode-ray tube 5. Moreover, such over-correction of the magnetic flux field tended to provide what is known as a forward red trapazoid" wherein the red and green traces have opposing slopes with the separation of the red traces at a minimum to the right of the viewing screen 11. Again, convergence with available apparatus was difiicult, if not impossible.

However, it was found that the above-mentioned reverse red trapezoid effect, due to under-correction of the magnetic flux field and the forward red trapazoid efi'ect due to overcorrection of the magnetic flux field, could be virtually eliminated by the proper selection of flux corrective measures. Thus, the employment of the flux-altering means 23 and 25 in conjunction with the pairs of added turns 27, 28 and 29, 30 properly spaced therefrom, provide a raster with red and green traces having substantially coincident arcs as illustrated in FIG. 7. Having rendered the slopes of the red and green arcs substantially coincident, it was found that the pincushioned raster is readily correctable by pincushion and convergence circuitry already available in most present-day color television receivers.

Thus, the pincushion circuitry readily available in triad-guntype color television receivers is employed, in the usual manner, to effect pincushion correction and convergence of the red and green traces of the electron beams of a color cathode-ray tube. Therefore, the toroid deflection yoke 7 is employable with a television receiver having the usual triadgun-type cathode-ray tube, pincushion-correction circuitry and convergence apparatus to provide a desired color-image display.

It should perhaps be further noted that the specific embodiment of a toroid-wound deflection yoke illustrated in FIG. 2 includes the added turns 27 and 28 of the first or left horizontal deflection winding 19, as well as the added turns 29 and 30 of the second or right horizontal deflection winding 21. Also, the added turns 27 and 28 are at a slightly different circumferential spacing from the horizontal axis I-I-I-I' than the added turns 29 and 30 due to the effect of the earth magnetic field in the Northern Hemisphere.

More specifically, FIGS. 8 and 9 will serve to illustrate the winding distribution of the

horizontal deflection windings

19 and 21 in a quadrant to the left and right of the vertical axis V-V. Therein, the X-axis represents the angular degrees 0 from the horizontal axis H-I-I while the y-axis numerals W represent the rim-order intercept of a wire group with respect to the horizontal axis H-H. Each of the wire groups W is considered to be a unit, three toroid turns in this instance, having a central acting vector unit of force insofar as the magnetic effect and angular degrees are concerned. Moreover, the wire and turn content of each of the wire groups W is varied to provide variations in impedance and may include one or a number of turns depending upon the impedance value desired.

Referring to FIG. 8, the curve is representative of the upper left quadrant as well as the lower left quadrant of the first or left horizontal deflection winding 19 since the winding is substantially symmetrical with respect to the horizontal axis H- I-l'. This curve of FIG. 8 may be represented by the following formulation:

W1=*().07469-l0.4285586*0.00577l60 -+-().000()682560 0.000000384020 wherein 0 =degrees from the horizontal axis l-I-I-l' to the center of influence of a wire group W W1 intercept of a wire group W in the left horizontal deflection winding 19 The upper right quadrant of the second or right horizontal deflection winding 21 is illustrated by the diagram of FIG. 9. As mentioned above, the lower right quadrant of the horizontal deflection winding 21 is also represented by the diagram of FIG. 9. In a formulation of the curve:

Wr=0.05 l0lO.435250-0.006210%.000076430 ().00000042964 wherein dz =degrees from the horizontal axis H-I-I' to the center of influence of a wire group W Wr rim-order intercept of a wire group W in the right horizontal deflection winding 21.

Additionally, FIG. 10 will serve to illustrate the winding distribution of the

vertical deflection windings

31 and 33. Herein, the x-axis represents the angular degrees d: from the vertical axis V-V' while the y-axis numerals represent the rim-order intercept of a wire group W with respect to the vertical axis V-V'. As mentioned above, each of the wire groups W represent a central acting vector of force, three toroid turns in this instance, of the

vertical windings

31 and 33. FIG. 10 will serve to represent quadrants to the left and right of the vertical axis V-V, as well as above and below the horizontal axis H- H, since the windings are symmetrical.

As represented by formulation:

=degrees from the vertical axis V-V to thecenter of influence of a wire group W Wv =rim-order intercept of a wire group W in the first and second

vertical deflection windings

31 and 33.

It should be noted that toroid-wound deflection yokes have been fabricated wherein both the first and second

horizontal deflection windings

19 and 21 and the first and second

vertical deflection windings

31 and 33 are symmetrical. In this instance, it has been found that the formulation Wr representative of the right horizontal deflection winding 21 is also employed in fabricating the left horizontal deflection winding 19. Moreover, it has been found that satisfactory results have been obtained when the degrees 0 from the horizontal axis I-I--H' and the degrees 43 from the vertical axis V--V' to the center of influence of the wire group W are not varied from the above formulations by more than about three degrees (3).

As to the employment of the above-described toroidal deflection yoke, FIG. 11 illustrates a typical television receiver employing the usual antenna 38 whereat transmitted television signals are intercepted and applied to a signal receiver 39. The signal receiver 39 includes the usual RF and IF signal amplifier and detector stages and provides an output signal which is applied via an audio-amplifier stage 40 to a loudspeaker 41. Another output from the signal receiver 39 includes signals representative of both luminance and synchronizing information and is applied to a video-amplifier 43.

One output signal available from the video-amplifier stage 43 and representative of luminescence information is applied to a control electrode of a cathode-ray tube 45. Another output signal available from the video-amplifier stage 43 and representative of synchronizing information is applied to a synchronizing separator stage 47. Therein, signals representative of vertical and horizontal scan frequencies are derived and applied to vertical and horizontal deflection stages 49 and 51 respectively.

The vertical deflection stage 49 is coupled via an output transformer 53 to a pair of output terminals YY' and one of the output terminals Y is AC-coupled by a capacitor 54 to a potential reference level such as circuit ground. In turn, the output terminals Y-Y' are coupled to a pair of series-connected vertical deflection coil windings, 55 and 57 associated with a cathode-ray tube 45.

In a somewhat similar manner, the horizontal deflection stage 51 is coupled to a horizontal output transformer winding 59. One end of the transformer winding 59 is coupled by way of a rectifier stage 61 to a high-voltage electrode of the cathode-ray tube 45 while the other end of the transformer winding 59 is coupled via a capacitor 68 to a DC-potential source B+. Also, a series-connected damper stage 65 and alterable inductor 67, linearity control, shunted by a tuning capacitor are coupled intermediate a junction of the transformer winding 59 and the DC-potential source B+.

Further, a pair of series connected horizontal deflection coils 69 and 71 associated with the cathode-ray tube 45 have one end thereof connected to a junction 73 of the transformer winding 59 and the other end coupled via the capacitor 63 to the DC-potential source 8+ and to the transformer winding 59. Moreover, a capacitor 75 is shunted across the horizontal deflection coil 71 connected to the end of the transformer winding 59 via

capacitors

63 and 68 and to the potential source 3+.

As can be more readily seen in FIG. 12, a toroidal-wound deflection yoke is schematically illustrated in cooperation with a triad-type color cathode-ray tube. Herein, the neck portion 77 of a color cathode-ray tube includes the triad of electron guns 79 and is surrounded by the toroid-wound deflection yoke 81.

As observed by a viewer of the screen of a cathode-ray tube, the first or left horizontal deflection winding 71 is associated with the beginning of the usual left-to-right horizontal scanning of the cathode-ray tube. This winding 71 is AC-coupled by a capacitor 63 to a DC-potential source 8+. A capacitor 75 shunts the winding 71 and a second or right horizontal deflection winding 69 series connects the first horizontal deflection winding 71 to a horizontal deflection signal source, 73 of P10. 11. Moreover, a portion of the transformer winding 59 is coupled by the storage boost capacitor 68 to the DC- potential source B+.

In a somewhat similar manner, a first or top vertical deflection winding 57 associated with the beginning of vertical scanning is AC-coupled by a capacitor 54, to a potential reference level such as circuit ground. The first vertical deflection winding 57 is series connected to a second vertical deflection winding 55 coupled to a vertical deflection signal source Y ofFlG. 11.

As to the operation of the above-described circuitry illustrated in FIGS. 11 and 12 in conjunction with the toroid deflection yoke 7, it is to be noted that the left or first horizontal deflection winding 71 and the first or top vertical deflection winding 57 are concerned with the start of both horizontal and vertical scanning. Also, the previously mentioned opposing circumferential directions of advancement of the windings serves to effect neutralization of the electrostatic charging of the distributed capacitance between first and second

vertical deflection windings

57 and 55 and the first and second

horizontal deflection windings

71 and 69.

Further, the mirror-image relationship of the windings assists in neutralizing magnetic and electrostatic cross-induction between the

horizontal windings

69 and 71 and the

vertical windings

55 and 57. This neutralization of electrostatic and magnetic cross-induction between horizontal and vertical winding is also aided by the substantially sawtooth connection of the

vertical windings

57 and 55 as well as the intermittent bank-wound-type connections of the

horizontal windings

71 and 69.

Additionally, the first horizontal deflection winding 71 most closely associated with the ringing effect has one end thereof coupled via the capacitor 63 to a potential reference level 8+ with the other end closely associated with the grounded end of the vertical deflection winding 57. Moreover, the horizontal winding 71 and the vertical winding are interleaved which also assists in draining undesired energy from both the horizontal and

vertical windings

71 and 57 associated with the start of both horizontal and vertical scan.

Moreover, undesired energy drain of the horizontal deflection winding 71 is even further enhanced by the shunting capacitor 75. Again, the shunting capacitor 75 provides a rapid path for energy drain to the potential reference level 3+.

Thus, it has been found that a viewer is subjected to a minimum of ringing by employment of a circuit arrangement wherein the deflection winding associated with the beginning of electron beam scanning is coupled to a reference level while the winding associated with the end of electron beam scanning is coupled to the signal source. Moreover, the arrangement is inexpensive of parts and of enhanced reliability as a result of the relative simplicity of the structure.

While there has been shown and described what is at present considered the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.

I claim:

l. A deflection-yoke-fabricating process comprising the steps of:

selecting a substantially circular core of magnetic material having horizontal and vertical axes;

forming first and second vertical deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said horizontal axis, each of said windings advancing in opposite circumferential direction and said turns being intermittently spaced to define a plurality of circumferential spaces; and

forming first and second horizontal deflection windings by toroidally wrapping a plurality of wire turns on said core in mirror-image relationship on opposite sides of said vertical axis, each of said windings advancing in an opposite circumferential direction and disposed in said spaces of said spaced first and second vertical deflection windings and in interleaving relationship with said first and second vertical deflection windings.

2. The combination of claim 1 wherein said first and second vertical deflection windings are in mirror-image relationship to one another about said horizontal axis.

3. The combination of claim 1 wherein each of said first and second vertical deflection windings is in mirror-image relationship about said vertical axis of said core.

4. The combination of claim 1 wherein each of said first and second horizontal deflection windings is in substantially mirror-image relationship about said horizontal axis of said core.

5. A deflection-yoke-fabricating process comprising the steps of:

forming first and second vertical deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said horizontal axis and advancing in an opposite circumferential direction, each of said windings including a first layer of spaced turns and a second layer of turns supported by said first layer of turns and electrically connected thereto by a sawtooth connection to provide a substantially constant potential difference intermediate adjacent first and second layer turns of each winding; and

forming first and second horizontal deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said vertical axis, each of said windings advancing in an opposite circumferential direction with said wire turns disposed in interleaving relationship with said first and second vertical deflection windings.

6. The process of claim 5 wherein said first and second horizontal deflection windings includes wire groups circumt'erentially spaced along said core and formed from a plurality of toroidal-wound wire turns.

7, The process of claim 5 including the steps of affixing a first layer of said first and second vertical deflection windings to said core, interleaving said first and second horizontal deflection windings with said first layer of said first and second vertical deflection windings, and affixing a second layer to said first layer of said first and second vertical deflection windings.

8. The process of claim 5 wherein each of said first and second horizontal deflection windings is in the form of circumferentially spaced bank-wound groups, each of said bankwound groups being formed by affixing at least one pair of wire turns to said core to provide a first layer and affixing a wire turn to said pair of wire turns of said first layer to provide a second layer.

9. The process of claim 8 wherein said wire turns of said first and second layers of each of said hank-wound wire groups are series-connected and advanced in the same circumferential direction.

10. The process of claim 8 wherein said bank-wound wire groups of each of said windings are series-connected and advanced in one circumferential direction.

11. A deflection-yoke-fabricating process comprising the steps of:

forming first and second vertical deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said horizontal axis; and

forming first and second horizontal deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said vertical axis, each of said first and second horizontal deflection windings being in the form of circumferentially spaced bank-wound groups with each of said bank-wound groups being formed by affixing at least one pair of wire turns to the core to provide a first layer and affixing at least one turn to said first layer to provide a second layer.

12. The process of claim 11 wherein said first and second vertical deflection windings each include spaced toroidally wrapped wire turns and said bank-wound groups of said first and second horizontal deflection windings are afi'lxed to said core and interleaved with said spaced first and second vertical deflection windings.

13. The process of claim 11 wherein said wire turns of each of said bank-wound groups are series-connected and advanced in the same circumferential direction.

14. The process of claim 11 including the steps of forming first and second vertical deflection windings by toroidally wrapping spaced wire turns about said core and interleaving first and second horizontal deflection windings in the form of wire groups within the spaces of said spaced wire turns of said first and second vertical deflection windings.

* t i t mg UNITED STATES PATENT OFFICE CERTIFICATE 6F CORRECTION Patent No. 3,631,902 Dated January 4, 1972 Inventor(s) Charles Edward Torsch.

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

In the Abstract, line 2, "torrid" should read "toroid" Col. 7, line 55, "-0.000000384029'.' should read "-0.000 00 Col. 7 line 59, "W1 intercept should read "Wl rim-order i intercept" Col. 7, line 66, "O.435259" should read "+0.435259" Col. 7 line 67 "-O .00OOOO42964" should read "-0.000 00 Col. line 13, "+O.345730.0Ol864l should read "+0.34673 O.0Ol864l Col. 8, lines 41-42, "amplifier 43" should read "amplifier stage 43" Signed and sealed this 1st day of August 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

1. A deflection-yoke-fabricating process comprising the steps of: selecting a substantially circular core of magnetic material having horizontal and vertical axes; forming first and second vertical deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said horizontal axis, each of said windings advancing in opposite circumferential direction and said turns being intermittently spaced to define a plurality of circumferential spaces; and forming first and second horizontal deflection windings by toroidally wrapping a plurality of wire turns on said core in mirror-image relationship on opposite sides of said vertical axis, each of said windings advancing in an opposite circumferential direction and disposed in said spaces of said spaced first and second vertical deflection windings and in interleaving relationship with said first and second vertical deflection windings.

5. A deflection-yoke-fabricating process comprising the steps of: selecting a substantially circular core of magnetic material having horizontal and vertical axes; forming first and second vertical deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said horizontal axis and advancing in an opposite circumferential direction, each of said windings including a first layer of spaced turns and a second layer of turns supported by said first layer of turns and electrically connected thereto by a sawtooth connection to provide a substantially constant potential difference intermediate adjacent first and second layer turns of each winding; and forming first and second horizontal deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said vertical axis, each of said windings advancing in an opposite circumferential direction with said wire turns disposed in interleaving relationship with said first and second vertical deflection windings.

6. The process of claim 5 wherein said first and second horizontal deflection windings includes wire groups circumferentially spaced along said core and formed from a plurality of toroidal-wound wire turns. 7, The process of claim 5 including the steps of affixing a first layer of said first and second vertical deflection windings to said core, interleaving said first and second horizontal deflection windings with said first layer of said first and second vertical deflection windings, and affixing a second layer to said first layer of said first and second vertical deflection windings.

8. The process of claim 5 wherein each of said first and second horizontal deflection windings is in the form of circumferentially spaced bank-wound groups, each of said bank-wound groups being formed by affixing at least one pair of wire turns to said core to provide a first layer and affixing a wire turn to said pair of wire turns of said first layer to provide a second layer.

9. The process of claim 8 wherein said wire turns of said first and second layers of each of said bank-wound wire groups are series-connected and advanced in the same circumferential direction.

11. A deflection-yoke-fabricating process comprising the steps of: selecting a substantially circular core of magnetic material having horizontal and vertical axes; forming first and second vertical deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said horizontal axis; and forMing first and second horizontal deflection windings by toroidally wrapping a plurality of wire turns on said core on opposite sides of said vertical axis, each of said first and second horizontal deflection windings being in the form of circumferentially spaced bank-wound groups with each of said bank-wound groups being formed by affixing at least one pair of wire turns to the core to provide a first layer and affixing at least one turn to said first layer to provide a second layer.

12. The process of claim 11 wherein said first and second vertical deflection windings each include spaced toroidally wrapped wire turns and said bank-wound groups of said first and second horizontal deflection windings are affixed to said core and interleaved with said spaced first and second vertical deflection windings.