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Патент USA US3094659

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June 18, 1963
J. MARLEY
3,094,649
MAGNETIC DEFLECTION YoKEs l
Original Filed Aug. 23, 1955
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June 18, 1963-
.LMARLEY
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3,094,649
MAGNETIC DEFLECTION YoxEs
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Original Filed Aug. 23, 1955
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United States Patent O
3,094,649
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VPatented June 18, 1963
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converter, provide linear scanning, develop uniform de
-flection fields which do not cause defocusing, and be free
3,094,649
John Marley, Wayne, NJ., assigner to Hazeltine Re
search, Inc., Chicago, lill., a corporation of Illinois
MAGNETIC DEFLECTIQN YOKES
from resonant ringing and from undesired interaction of
the vertical and horizontal fields. In addition, the yoke
should be inexpensive and there should be a high degree
of consistency between the deflection fields developed by
Original application Aug. 23, 1955, Ser. No. 530,029, now
Patent No. 3,015,152, dated Jan. 2, 1962.
Divided
and this application Apr. 20, 1961, Ser. No. 104,359
7 Claims. (Cl. 317--200)
General
yokes of the same construction. With the advent of the
wide-angle picture tubes having deflection angles
approaching 90° and having an extremely short neck por
10 tion, it has become difficult to satisfy these requirements.
The invention is directed to a method of manufacturing
electron-beam deflection yokes utilized -to effect lateral
motion of beams of electrons or similar electr-ical particles
and is particularly directed to a method of manufacturing
magnetic deflection yokes of this type. These yokes are
particularly useful for dellecting «the electron beams in
cathode-ray Ytubes of the types conventionally employed
in Oscilloscopes, target indicators, and most commonly
used in television receivers. To a large degree the strin 20
gency of the requirements of deflection yokes determines
It has been conventional to utilize “saddle” yokes, so
called because of the “saddle”-like configuration of each
of the four coils which combine to form the yoke. Be
cause of the complex configuration of these coils, “saddle”
yokes require complex winding apparatus which indi
vidually winds each of the’four coils and which, in spite
of its complexity, fails to maintaina uniform or any other
desired spatial relationship to the turns in each coil or
to wind coils which are consistently the same. After the
»winding process, .the coils usuallyrequire additional shap
ing by manual or mechanical means to assume the “sad
the methods of manufacturing these yokes. Since tele
dle” form. The latter operationintroduces additional
vision deflection yokes have the most exacting require
inconsistencies betweencoils and addi-tional irregularities
ments, the process of manufacturing such a yoke will be
within each coil. "Pour coils so formed are then nested
described herein. However, it should be understood that 25 with a winding of one coil in the cavity or window of
the method of manufacturing deflection yokes in accord
another Eto provide the complete deflection yoke. The
ance with the present invention may be employed in other
latter assembly operation introduces additional incon
than the manufacture of television yokes.
sistency characteristics between yokes of the same type.
This application is a division of application Serial No.
As a result of the above-mentioned factors, “saddle”
530,029, filed August 23, 1955, now Patent No. 3,015,152 30 yokes have field irregularities and a lack of consistency
and entitled “Process of Manufacturing Magnetic Dedec
in fields developed by yokes of the same time. To com
tion Yokes.”
pensate for the field irregularities and the variations be
The fundamental principles underlying television trans
tween lields developed by. differentcoils of thesame type,
mission and reception and the details of the apparatus
only a small segment at 'the center of the field pattern
employed are so well known it is deemed unnecessary for
developed by a yoke is used for deflection. The inner sur
the purpose of the present invention to describe a com
faces of the coils forming the yoke are spaced from the
plete television transmitter or receiver. It is well knovm
in the art to employ cathode-ray tubes of various forms
neck of the tube in order to minimize the effects of field
irregularities which are strongest in the vicinity of the
coil surfaces. Since only a relatively small portion of
in conventional television receivers to reproduce televised
images. To effect such reproduction, the cathode-ray 40 the total field developed by a yoke is employed, conven
tubes include means for emitting an electron beam which
is intensity modulated -by video-frequency information.
tional “saddle”y yokes tend to be expensive, large, >and
heavy, and they develop deflection fields which are less
This beam is focused into an extremely narrow beam to
uniform than is desired and which fail to provide the
provide the high definition required in reproducing the
degree of control of deflection of the beam required for
televised image and is deflected in two orthogonal direc
best reproduction of the image. The present methods of
tions to scan a rectangular raster on the image screen of
physically windingl wire into complex coil forms -and then
the picture tube to provide a two-dimensional reproduced
assembling the complex coils into a “saddle” yoke make
image. Focusing of the electron beam is ordinarily
the elimination of the above-described undesired factors
accomplished by providing nonuniform magnetic or elec
extremely difficult. Therefore, it is desirable to practice
ftric fields of regular conñguration in the space traversed 50 new methods of manufacturing deflection yokes, thereby
by the electron beam between the cathode and the image
producing improved deflection yokes.
screen. Deflection of the focused electron beam is effected
It is, therefore, an object of the present invention to
by developing varying electric or magnetic fields in the
provide deflection yokes which do not have the defi
space traversed by the beam between the point of focusing
ciencies and limitations of prior yokes.
and the image screen. The present invention is directed 55
It is an additional object of the present invention to
to deflection yokes for developing such varying magnetic
provide deflection yokes utilizing printed wiring tech
deflection fields.
niques.
As is well known, a beam of electrons passing through
n It is still another object of the present invention to pro
a magnetic field is deflected in a direction perpendicular
vide deflection yokes which are easily and simply pro
00
to the instantaneous direction of motion of the electrons
duced to have constant kmagnetic characteristics.
in the beam and to the lines of magnetic force cut by the
It isy a further >object of the present invention to provide
beam. In order to effect continuous and uniform deflec
deflection yokes in which a plurality «of windings lare
tion of the beam in the horizontal and vertical directions,
preformed in fixed spatial relationship.
the intensities of the components of the magnetic field in
In accordance with the present invention, a cathode
these two directions are Varied, usually by employing sep 65 ray tube deflection-'yoke comprises a'yoke core including
arate coils of complex configurations with their axes
individual core Walis land a ldielectric sheet bearing a con
mutually perpendicular in which the magnitudes of the
tinuous loop-type conductor pattern encircling a wall of
currents in the separate coils are varied independently to
the yoke c_ore so that the two coils formed by the two
provide mutually perpendicular ñelds.
lsides of the loop-type conductorpattern fall in different
Progressive advancements in the art of «television have 70
'radial quadrants of the core.
imposed rather stringent requirements upon deflection
Referring to the drawings:
yokes. A deflection yoke should be an efficient power
3,094,649
3
4
FIG. l is a perspective view of a deflection yoke in ac
cordance with the present invention, mounted on the neck
ture, will fan out radially from the cathode-ray tube axis.
It will be noted that the coil 12, when viewed in its un
of a cathode-ray tube shown in fragmentary form;
folded form as shown in FIG. 3, is a continuous coil
FIG. 2 is a front elevation view of the yoke of FIG. l,
Vwith la portion cut away to show interior detail;
winding having a plurality of elongated rectangular-like
FIG. 3 is a plan view of a strip of dielectric material
including one of the coils utilized in Ithe yoke of FIGS.
l and 2, and
FIG. 4 is a plan view of a strip of dielectric material
including a modified form of coil winding.
10
Description of Deflection Yoke
In FIG. 1 a perspective view of a deflection yoke 10
manufactured in accordance with the present invention
turns which progress in a spiral-like manner towards the
center region of the unfolded coil winding.
The conductors in each of the coils 12-15, inclusive, are
formed by employing printed circuit techniques and are,
for example, approximately 15 mils wide, 1.5 mils thick,
and are separated from each other «by approximately 15
mils. For simplicity of representation, in FIGS. 1 and
3 only a few conductors have been shown representing
each `of the windings and the relative conductor sizes and
spacings are not to scale. In practice, the density of the
is shown, mounted on the neck of .a cathode-ray tube 11 15 conductors, as well as the total number and size of the
which may be, for example, the picture tube of a television
conductors, is controlled by the field strength desired.
receiver. The yoke V10 is circular in cross section and
The pattern of the spacings of the conductors is deter
preferably tits closely around the neck of the tube 11
mined .by the field pattern desired. For example, if a
with one end of the yoke, more specifically the beam-exit
cosine ñeld pattern is needed to correct lfor such problems
end, extending over at least a small length of the flared
as pin-cushion or barrel distortion, then the windings are
portion of the tube 11. The yoke 10 includes four com
spaced or have distributed -density according to a cosine
plete coils 12-15, inclusive, which are identical in shape
pattern.
and form, -but which ldiffer in size and may differ in the
The side windings 12a and 12b, specifically the narrow
size or number of conductors. Each of these coils sur
sections 18 of these windings, provide the deflection
rounds 180“ of the surface of a ring core 16. For ex 25 energy for dellecting the cathode-ray tube beam, the
ample, as represented in FIG. 2, the coil 12 occupies
wide, flaring and converging sections 19' and 20 Serving
the first 4and fourth quadrants, the coil 13 the second and
lonly to complete Ithe current path for the narrow sections.
third, the coil 14 the first and second, and the coil 15
The center portion of the dielectric sheet may be omitted
»the third and fourth quadrants of the circle formed by
when the sheet is manufactured or may be cut out before
the core 16. As is lapparent from the drawing, the di 30 or after the conductors have been formed on the sheet,
mensions of the coils 14 and 15 are such that they may
thus leaving an open region 21 as shown in FIG. 3. In
be placed within the outer coils -12 and 13.
addition, slits, represented by the dashed lines in FIG. 3,
Each of the coils `12~-15, inclusive, is supported on a
are made between conductors in Vthe converging and
dielectric sheet and, when in their assembled form as
flaring sections 20 to facilitate the winding of the sheet
shown in FIG. l, each includes a pair of distinct, though 35 of conductors into a tubular form and the bending of
interconnected, windings. Referring to FIGS. 1 and 2,
the tube to fit over an `arc of the core 16. The lengths
the coil 12, for example, has a pair of distinct windings
of the different sections in the coil sides are made pro
12a and 12b. These windings are shown in FIG. 3
gressively longer. That is, for example, the length of
in more detail and in unfolded form. The two distinct
the second narrow section, counting yfrom the end 12d
windings result when the dielectric sheet 17 of -FIG. 3
is rolled up around, for example, the end turns 12d, the
40 in a coil side such as side 12b, is longer than that of the
winding 12a being formed by the rolled-up side 12a;
while the winding 12b is formed by the rolled-up side
first, and -the third is longer than that of the second. The
difference in length is determined by the thickness of the
dielectric sheet, resulting in the successive circumferences
or" the layers of the sheet when wound in tubular form
12b. It is apparent that these two- -windings are inter
connected by the end turns 12C and 12d.
45 becoming progressively larger.
The coils 12-15, inclusive, are so disposed with respect
A group of coils of the type represented by FIG. 3,
to each other around the neck of the tube as to develop
after each has been rolled into a ñattened or rectangular
mutually perpendicular magnetic axes to effect horizon
tube about an axis parallel to the coil ends, for example,
tal yand vertical deñection of the beam in the tube. For
the ends 12C and 12d, are combined on the ring core 16
example, assuming the coils 12 and `13 having windings 50 in
the order represented in FIG. 1 to provide a complete
12a, I12b and 13a, 13b develop the vertical deñection iield,
deflection yoke. The core 16 may be, for example, of
then windings 14a, 14b and 15a, 15b of coils 14 and 15,
ferromagnetic material such as ferrite in order to provide
respectively, are utilized to develop the horizontal deflec
a low reluctance return path for the magnetic flux de
tion field. Each of the coil windings such as, for example,
veloped by the coils and preferably is separable into
the winding 12a of coil 12 occupies approximately 60° 55 quadrant
pieces to facilitate the threading of the tubular
of the circumference of the ring core 16, the windings
coil structure onto the core in the desired order. The
12a, 12b and 13a, 13b individually overlapping portions
of the windings I14a, 14b and 15a, 15b.
-Referring now to FIG. 3, each of the coils .i12-15,
inclusive, as represented by coil 11 in FIG. 3, is supported 60
on a sheet of dielectric material 17 and has rectangularly
coils enclose the walls of the core, land the coil sides 12a
and 12b are parallel to the axis of the core. The beam
deflection or narrow sections 18 of the coil sides are super
posed on the inner and the wide or current-return sections
19 superposed on the outer walls of the core 16. The
coils are secured about the circumference of the core, after
disposed ñat ends corresponding to the ends 12e and 12d
as well as ñat sides corresponding to the sides 12a and
being adjusted in proper spatial relationship, by means of
12b. ‘By “flat” is meant that the ends and sides of the
an adhesive on the core or by adhesive tape.
coil lay iiat against the surface of the dielectric sheet 17. 65
Method of Manufacturing Deflection Yoke
The sides of these coils, as represented by the sides 12a
tand 12b in FIG. 3, have alternate beam-deflection sec
The process of manufacturing a deflection yoke in ac
tions 18 and current-return sections 19, connected by al
cordance with the present invention commences with the
ternate ñaring and converging sections 20. For the form
preparation of an elongated rectangular-like coil winding,
of coil construction shown in FIG. 3, the beam-deflection 70 such as represented by FIG. 3, on each of a plurality of
sections 18 are relatively narrow in the vertical dimension
dielectric sheets. These sheets may be, for example, of
of the drawing, while the current-return sections 19 are
some thin flexible plastic material, such as vinylite or a
relatively wide sections. This configuration is desirable
phenolic Fiberglas, and are either of a rectangular shape,
so that the conductors of the flaring and converging sec
including a center portion, or of similar shape, without
tions 20, which form the end turns of the assembled struc 75 the center portion. By means of conventional printed
..
,5
3,094,649
.
wiring processes a coil, for example coil 12 having sides
Modijîed Coil Structure of FIGÍ. 4
12a and 12b and ends 12C and 12d and in which the
sides. have alternate wide and narrow sections connected
Referring now to FIG». 4 of the drawings, there is shown.`
an alternative form- of conductor pattern that- may be
printed on the dielectric .sheet 11 and which should be
mentioned iny detail because `of the reduced. energy losses`
associated with` a deflection- yoke which utilizes suchl a>
conductor pattern. The conductor pattern, as shown on
the unfolded dielectric. sheet 1'7- of FIG. 4, is similar to»
by alternate flaring and converging sections, is formed on
each dielectric sheet. The printing process may, for ex
ample, comprise etching the conductors for each coil out
of a thin copper plating coating the dielectric sheet, con
ventionally known as copper-clad. Alternatively, each
coil may be impressed’ or sprayed onto the dielectric sheet
to form copper, silver, or other conductive material. `Con
ventional printing or spraying processes can be employed.
In forming the coils on. the dielectric sheet, each setV of
four sections of a coil', for example the sections including.
a wide, a narrow, a flaring, and a converging portion, is'
the pattern on the unfolded dielectric sheet shownin FIG.
core. The length of the ñrst narrow section is determined
lay on top of one another onY the outside of lthe core
3,v except that the current-return sections 19 on» opposite
sides 12a and 12b of the conductor pattern` havev beenl
positioned more closely to one another.
The conductor pattern on the dielectric sheet 1T of
FIG. 4> is` rolled up in thev samev manner as previously
made progressively longer to compensate for the addition 15 describe-d, so asV to ‘form` a flattened tubular structurey
al circumference in each coil layer of four. sections. The
which may be placed on> the ring coreV 16 of. the deflec
lengths of the first four sections are determined by the
tion yoke. It will be apparent that when this is done,
length of the ñrst narrowy section and the thickness of the
the more closelyy spaced current-return sections 19 will-
by the deflection force desiredl and is limited by the. avail 20 16. Now, as. the current flow in the current-return> sec
able length on the neck of the picture tube. Each coil is
tions =19 making up the» side 12a is ñowing in a direction
one continuous loop of conductors having terminals as
opposite to the current flowing4 in the sections. 19 making,
indicated by the reference letters` T and T’ in FIG. 3.
up the side 12b, the magnetic fields produced by adjacent
If desired, slits, as represented by the dashed lines, are
sections'on the two sides 12m and Á12b of the conductor
cut or otherwise formed between the conductors in the 25 pattern will partially cancel one another.
flaring and converging sections to facilitate the forming
of the dielectric sheet and the coil thereon into a flattened
tube. If slits are provided, they should be slightly longer
than the flaring and converging sections, but not so long
means that>
less-energy will be stored in the magnetic fields produced
by the current-return sections and, hence, the energy
losses due to eddy currents, etc.,> Will be reduced, thus
resulting in a more efficient operation. of a deflection
as to disturb- the fixed spacing of at least the conductors 30 yoke utilizing such conductor patterns.
in each narrow section.
While the conductor configuration shown in FIG. 4
Each sheet so prepared is rolled on a mandrel or by
indicates one manner in which the current-return sections
other means about .an axis parallel to the ends of the
19 of the coil 12 may be spaced more closely to onecoil so that the coil sides are normal to this axis and form
another, it Will be apparent to those skilled in the art
rings at the ends of the tube formed by the sheet. The
folding process is such that corresponding sections in eachv
side, as well as the two end sections, are superposed. In
other words, each layer in the flattened tube includes a
set of the four coil sections with, for example, all of the
that other configurations are possible for producing the
desired magnetic field cancellation. Any conductor pat
tern whereink the current-return sections on opposite sides
of the conductor pattern are brought into a closely adja
cent relationship with one another will produce the de
beam-deflectiony or narrow sections 18 in the different 40
layers superposed. For coils 14 and 15, the interior di
mensions of the tubes formed by the coils are approxi
mately equal to the outside dimensions of the coil 16.
sired results.
In deflection yokes of any of the foregoing types,.the
conductors in each of the coils areA constrained asa
result of being printed in `fixed position to have fixed
Coils 12 and 13 form tubes in which the internal dimen
and consistent spatial relationships with- respect to each
45
sions are approximately equal to the outside dimensions
other. As a result, uniform coils or coils with conductors
of the coils 14 and 15. 'In view of the difference in size
nonuniformly distributed in any desired pattern are con
ofthe tubes formed by the-different coils, coils 12 and 13
sistently manufactured. The magnetic fields developed-by
have longer sides andv each ofthe-sections in each side is
coils
manufactured in the manner described herein are
correspondingly longer than the sides and the sections of
50 as exact and controlled »in pattern as desired and are
coils 14 and 15.
consistently duplicated. This results in a relatively inex
As previously mentioned, the core 16 is preferably
broken into four quadrant pieces having irregular rather
than machined mating edges. The irregular mating edges
of adjacent pieces provide greater contact surfaces, there
pensive and light-weight deflection yoke which provides
cross over at intermediate points to delete the total num
without departing from the invention, and it is, therefore,
greatly improved deflection and has a minimum disturb
ing effect on the focusing of an electron beam.
Though relatively simple deflection yokes and their
by decreasing interface effects. One quadrant of the core 55
manufacture have been described and no extensive dis
16 is threaded through the internal openings in the tubes
cussion of techniques for correcting for Well-known de
formed by the coils 14 and 12 in the order mentioned to
ñciencies
in 'yokes has been presented, it should be ap
provide the upper right-hand or first quadrant of the yoke
parent to those skilled in the art that many of the prac
of FIGS, l and 2. In a similar manner, the second
quadrant of the core 16 is threaded through the tubes 60 tices which are conventionally employed to develop mag
netic field patterns of suitable distribution to correct for
formed by coils 14 and 13, the third quadrant through
field deficiencies may equally well be employed in the
the tubes formed by coils 15 and 13, and the fourth
preparation `of a yoke such as described herein. In fact,
quadrant through the tubes formed by coils 1S and 12 in
the use of printed-wiring techniques facilitates the ob
that order. The quadrant sections of the core are then
65 taining of many of these corrective effects `by simplifying
fitted together to form the cylindrical or ring core 16 and
the grading of conductor size and spacing of conductors
are secured in that position by use of adhesive or by tape
in any »desired manner to obtain field patterns which pro
which secures the different coils in proper position. A
vide the corrective effects desired.
dust cover (not shown) and a magnetic shield (not shown)
While there have been described what are, at present,
may be added to enclose and protect the coils. In addi 70 considered to be the preferred embodiments of this in
tion, considering PIG. 3, not all of the end turns at ends
vention, it will be obvious to those skilled in the art that
various changes and modifications may be made therein
12e .and 12d need cross over at the very ends. Some may
aimed to cover .all such changes and modifications as fall
ber of turns per layer of coil as the layers build up.
This saves cost and space with little loss in magnetic iiux. 75 within the true spirit and scope of the invention.
8,094,649
7
What is claimed is:
l. A cathode-ray tube deflection yoke comprising: a
8
are spaced nearer to and farther from one another and
are connected by intervening oblique sections, the dielec
yoke core including individual core walls and a dielectric
tric sheet encircling a wall of the yoke core so that for
sheet, bearing a continuous loop-type conductor pattern
each elongated side of the loop-type conductor pattern
encircling a wall of the yoke core so that the two coils 5 the farther-spaced sections are superimposed on top of
formed by the two sides of the loop-type conductor pat
one another on the inner side of the core, the nearer
tern fall in different radial quadrants of the core.
spaced sections are superimposed on top of one another
2. A cathode-ray tube deñection yoke comprising: a
on the outer `side of the core, and the oblique sections
yoke core including individual core walls and a dielectric
are superimposed on top of one another on the two ends
sheet, having printed thereon a continuous loop-type con
of the core and so that the inner portions of the two
ductor pattern, encircling a wall of the yoke core so
deflection coils thus formed fall in diiîerent radial quad
that the two coils formed by the two sides of the loop
rants of the core with the nearer-spaced outer portions
type conductor pattern fall in diiîerent radial quadrants
closely adjacent one another so that their magnetic fields
of the core.
tend to cancel each other.
3. A cathode-ray tube deflection yoke comprising: a
6. A cathode-ray tube deflection yoke comprising: a
yoke core including individual core Walls and a dielectric
yoke core including individual core walls and two sets
sheet, bearing a continuous loop-type conductor pattern
having two elongated sides joined by two short sides,
of coils comprising a plurality of dielectric sheets, each
bearing a continuous loop-type conductor pattern,
encircling »a Wall of the yoke core so that the two coils
wrapped around the yoke core so that the two coils formed
formed by the two elongated sides of the loop-type con 20 by the two sides of each of the loop-type conductor pat
ductor pattern fall in diiîerent radial quadrants of the
terns fall in `different radial quadrants of the core, one
core with the short sides positioned on top of one another
set of the coils encircling a wall of the core to produce
on the outer side of the core so that their magnetic fields
a first deflection Íield and the other set surrounding the
tend to cancel each other.
'
core wall to produce a second deñection ñeld at right
4. A cathode-ray tube deflection yoke comprising: a 25 angles to the ñrst field.
yoke core including individual core walls Iand a dielectric
7. A cathode-ray tube deflection yoke comprising: a
sheet, fbearing a continuous loop-type conductor pattern
yoke core including individual core walls, a ñrst set of
having two elongated sides joined by two short sides with
coils for producing a first deflection ñeld and comprising
the elongated sides having alternate wide and narrow
two dielectric sheets, each bearing a continuous loop-type
30
sections connected by alternate ñaring land converging sec
conductor pattern, encircling a wall of the yoke core so
tions, the dielectric sheet encircling a Wall of the yoke
that the two coils formed by the two sides of each of
core so that for each elongated side of the loop-type con-`
the loop-type conductor patterns fall in adjacent radial
ductor pattern the narrow sections are superimposed on
top of one another on the inner side of the core, the
quadrants of the core with one pair on one half of the
core and the other pair on the other half; and a second
wide sections are superimposed on top of one another 35, set of coils for producing a second deflection ñeld at
on the outer side of the core, the flaring sections are
right angles to the íirst dellection ñeld and comprising
superimposed on top of one another on one end of the
core, and the converging sections are superimposed on
top of one another on the other end of the core and
two dielectric sheets, each bearing a continuous loop-type
conductor pattern, surrounding the wall of the yoke core
40 on top of the iirst set of coils to form two pairs of coils
so that the two deflection coils thus formed fall in dif
similar to the coils of the first set except that the posi
ferent radial quadrants of the core with the conductors
tioning of the second set is displaced 90 degrees relative
in the ñaring and converging sections directed radially of
to that of the ñrst set.
the core to minimize the effects of their magnetic ñelds.
5. A cathode-ray tube deñection yoke comprising: a
References Cited in the file of this patent
yoke core including individual core walls and a dielectric
UNITED STATES PATENTS
sheet, bearing a continuous loop-type conductor pattern
having two elongated sides joined by two short sides
with the elongated sides having alternate sections which
2,817,782
2,830,212
Over et a1. __________ __ Dec. 24, 1957
Hanlet _______________ __ Apr. 8, 1958
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