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Патент USA US2412965

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Dec. 24, 1946.
Filed July 10, 1941
Patented Dec. 24, 1946
maar orties
Georges Paul Chevigny, Kew Gardens, and Henri
G. Busignies, Forest Hills, N. Y., assignors to
International Standard Electric Corporation
Application July 10, 1941, Serial No. 401,740
S Claims. (Cl. Z50-_158)
This invention relates to improvements in elec
trodes for electron discharge devices, and in par
ticular to improved deflecting electrodes for cath
ode ray tubes.
of the spot extending along any entire radius of
the screen. It is thus possible, when desired, to
return the beam spot to the center of the screen
with each control Voltage impulse.
How such a ñeld may be set up and its effect
upon a pair of electrons may be appreciated by
referring to the schematic showing of Fig. 1.
deflection of a cathode ray beam.
In this drawing three relatively short sets of con
Another object is to increase the sensitivity of
centric conical electrodes I0, II, I2 illustrate
cathode ray devices.
A further object is to provide improved means 10 what sort of effect may be expected of the pro
posed non-conical concentric electrode structure.
for controlling the amount of deflection of a
The beam of electrons I3 may have a normal
cathode ray beam for given applied deflecting
trajectory sweeping circularly so as to describe
a generally circular orbit I4, I5 on the fluorescent
Other objects and various further features of
screen of the tube. Now the effect of a relatively
novelty and invention will hereinafter be pointed
positive potential on the inner electrode I0' with
out or will become apparent from a reading of the
respect to the corresponding outer one I0 will be
following specification in conjunction with the
to set up a radially inwardly extending potential
drawing included herewith. In said drawing
gradient in the generally annular intervening
Figs. l and 2 are schematic showings illustrat~
ing principles of operation of devices according 20 space. A sudden application of this relative po
tential will therefore deflect the beam a slight
to the invention, and
amount to make it follow a new course I6 and
Figs. 3 and 4 are partly broken away and partly
to strike radially inwardly to some circumferen
sectionalized showings of preferred forms of the
tial point on the orbit Il, I8.
A corresponding or similar relative potential
When a cathode ray tube is employed as a 25
applied between the next set of elements II, Il’
device for indicating some quantity such as a
may have a like deiiecting effect upon the beam,
phase angle, it is customary to set up a circular
It is an object of the invention to provide irn
proved means for controlling the magnitude of
sweep of the ray by means of quadrature cur
rents applied to the deflection plates and to mod
ulate this sweep radially with a control Voltage 3
proportional to the quantity in question. Such
a control voltage may be applied to various elec
trodes, and as a rule it is applied between a pair
causing redeflection; and the simultaneous appli
cation of such potentials to elements I0, I0', I I, I I'
may cause further deflection of the beam so as
to strike orbit I9 peripherally. By applying addi
tionally a strong enough potential between ele
' ments l2, i2', it appears clear that the beam may
be caused to extend to the center of the screen,
flecting plates and the screen. These concen- i Ol or even further, if so desired.
While the above described electrode arrange
tric electrodes may be of generally conical form
ment may seem feasible, we vconsider it far too
and are considered undesirable because they per
complex to be practical and, accordingly, prefer
mit only a very limited degree of radial modu~
a more unitary construction, as shown in Fig. 2.
lation of the beam, and this to such an extent
In the form shown, the outer electrode 20 of the
that it is not possible to form a spot near the
structure is of generally conical form. A gener
center of the tube.
ally barrel-shaped concentric inner electrode ZI
It is well known that the extent of radial de
seems to be preferable as it will permit almost any
flection of a cathode ray depends upon the poten
degree of radial deflection that may be desired.
tial gradient transverse to the beam and upon
of concentric electrodes disposed between the de
the distance that the beam must traverse through
a field having this gradient. With the known
forms of concentric conical electrodes, both elec
trodes must be relatively closely spaced in order
to maintain a uniform control field therebetween.
As a result it is only possible to obtain relatively
limited radial deflections.
We have found that, by varying the shape of
these concentric electrodes whereby a barrel
shaped path is prescribed for the electron'beam,
it will be possible to provide for radial deflection
Furthermore, if desired an electronéintercepting
disc-shaped plate electrode 22 may be provided,
and this electrode may serve to limit the degree
of radial deiiection. In the form shown, electrode
2i intercepts all electrons that are deflected so
much that they otherwise would form images on
the fluorescent screen on both sides of the center
of the screen.
. The embodiment just describedmay ñnd par
ticular application in radiogoniometric systems
in which it is desired to obtain a veryv clear an--
gular indication upon a cathode ray tube screen.
A circular sweep will continuously rotate the
beam about an outer orbit 23; and, if angular
indication impulse energy is applied between
members 2| and 2|), a sharply defined radial in
dication may be obtained. In other applications
it may be desirable to show two angular indica
tionsv simultaneously on the screen.
radial deflection structure 24', 26’.
'I'he mag
netic deñection means for one axial sense is
shown schematically to comprise a pair of coils
3l), 3|. For purposes of clarity the other pair
of coils for deflection, say, in a sense perpen
dicular to that of coils 39, 3|, is omitted from
the drawing. It is clear that by providing mag
In such a
netic means for generating the circular sweeping
energy, it is possible to arrange this circular de
members 20 and 2| to a mean biasing gradient, 10 flection to take place at substantially the same
a de?lecting potential in one polarity sense could
axial position as the radial deflection, due to
serve to produce outward radial deflection mo
members 24', 2t’. This arrangement is consid
mentarily, and a deflecting potential in the op
ered preferable inasmuch as members 24', 26'
posite polarity sense could serve to produce an
may extend into close proximity with the electron
inward momentary deñection. Thus, two simul 15 gun and circular sweeping may be performed
taneous indications could be obtained with ut«
simultaneously with radial deflection.
most clarity on the screen; and there could be no
Fig. 4 additionally illustrates a preferred means
case, by properly adjusting the potential between
confusion as to the identity of each, inasmuch
or manner of supporting our novel electrode
as each indication would extend radially in an
opposite sense with respect to the other.
As indicated above, certain features of the in
vention relate to electrode means whereby effec
tlve cathode ray tube magniñcation may be in
Since electrons pass within member
25S', this electrode may be supported in a conven
tional manner by a relatively rigid lead in mem
ber 32. Appropriate support for the inner elec
trode 2è’ presents more of a problem, but this
creased or decreased as desired. It is thus con
may `be accomplished by means of a rigid lead-in
templated that electrode means may be made to
line 33, sealed to the center of the bulb or screen
adapt the applied signal indications to a showing
Y end 34 of the tube. In order not to have poten
utilizing the entire cathode ray screen to best
tials impressed on line 33 in any way interfere
advantage. - To this end, concentric electrodes
with the passage of electrons as controlled by
analogous to those above discussed in connec
members 2li’ and 2&3’ and the magnetic coils, we
tion with the forms of Figs. 1 and 2 may be em
propose that line 33 comprise a yconcentric line,
ployed. However, for maximum deflecting effl
as shown clearly in the broken-away portion.
ciency it is preferred that these concentric elec
Control potentials may be supplied to electrode
trodes be disposed as near as possible to the out~
24’ by means of inner conductor 35. The outer
let of the electron gun.
‘conductor 36 may be electrically spaced from
Such an arrangement, utilizing electrostatic 35 electrode 2li’ by means of an insulating washer
deflection throughout, is shown in Fig. 3. In the
3l', and if it is given a potential equal to sub
form shown the inner member 2li of the concen
stantially that of the fluorescent screen, varying
tric electrode structure is of tear drop shape
potentials on inner conductor 35 will have no
with the pointed end directed toward the electron
el-Iect upon the electron lbeam except as applied
gun 25. In order to locate the concentric ele-c 40 to electrode 24’.
trodes 24, 26 as close to the origin of deflection
In designing electrode structures in accordance
as possible the lateral or sweep circuit deflection
with thev invention, it is considered preferable
plates 21 are preferably of minimum size, that is,
that the form of the outer electrode approximate
only large enough slightly to deflect the beam so
the shape of average ilight of the electron beam.
as to avoid collision with the inner electrode 2d. . Thus, in Fig. 2, outer electrode 2li is substan
It will be recalled by analogy of the form of elec
trode structure 24, 26 to those of the foregoing
figures, that its function will be of a biasing na
ture, determining in effect a magniñcation or
diminution of deiiections originating at the plates
It is lbelieved that, since deflection plates 21
are so small, their accuracy of control may not
be as great as desired. In this case, we propose
tially frusto-‘conicaL the electrode structure be
ing spaced substantially from the electron gun or
origin of deñection (not shown); and in Fig. 4
electrode 26’ is of the form of a generally inverse
hyper-bola or parabola of revolution, since it is
disposed near the origin of deiiection.
Although the invention has been described in
particular detail in connection with the preferred
forms illustrated, it is to be understood as not
the use of an additional set of relatively large
limited merely thereto.
plates 23 disposed in the same electrical sense or
phase relation as plates 21, whereby a more strict
What is claimed is:
and uniform control of sweeping may be assured.
Although this additional set of plates 28 seems
to us at present to have particular application in
cooperation with set 21 for generating a circular
sweep, it is clear that plates 28 may be energized
Wholly independent of plates 21 and employed for
other purposes.
In another` form of the invention it is possible
to eliminate any need for two sets of deflecting
plates, as in the case of Fig. 3, and at the saine
time to maintain as high eñ‘lciency and accuracy
of the sweeping operation. This alternate form
is shown in Fig. 4 in which the arrangement of
elements is substantially that of Fig. 3 with the
exception that magnetic means are used for de
flection rather than electrostatic means. The
tube of Fig. 4f thus comprises within an evacuated
envelope 29, an electron gun 25’ anda concentricl
1. In a cathode ray device, an electron gun,
lateral deñection means, a iluorescent screen, and
concentric electrostatic deflection means for
radial deflection, said last-mentioned means
comprising an inner generally cylindrical mem
ber and an outer generally cylindrical member,
said members diverging progressively with re
spect to each other toward said fluorescent
2. In a cathode ray device, an electron gun,
lateral deflection means, a iiuorescent screen, and
concentric electrostatic deflection means for
radial deiiection, said last-mentioned means com
prising inner generally cylindrical electrode
means and outer generally cylindrical electrode
means, said inner electrode means and said outer
electrode means diverging progressively with re
spect to each other toward said fluorescent
3. A cathode ray device according to claim 1,
`6. A cathode ray device according to claim 1,
further comprising a disc-shaped target electrode
in Which said inner member is of generally coni
cal form having an apex in proximity to said
electron gun.
4. A cathode ray device according to claim 1,
in Which said lateral deflection means comprises
coil means disposed about said device at sub
stantially the same axial location as said concen
-tric deflection means.
5. In a cathode ray device having a generally
between said concentric means and said ñuores
cent screen, said target electrode being coaxially
disposed with respect to said concentric means.
'7. In a cathode ray device, an electron gun, a
ñrst set of lateral deflection plates, a concentric
electrode structure concentric with said gun and
cylindrical electrode disposed coaXially of the de
more remote from said gun than said first set of
plates, and a second set of lateral deñection
plates more remote from said gun than said con
vice, a support for said electrode comprising a
centric structure,
relatively rigid lead-in secured to the center of
8. A cathode ray device according to claim 'I in
which said first and said second sets of deflection
plates are similar in number and are connected
in the same electrical phase relation.
one end of said device and to said electrode, said
lead-in including a coaxial line having an inner
conductor and an outer conductor, said inner
conductor being conductively associated with said
electrode, and said outer conductor being in
sulated from said electrode and providing a con
ducting shield for said inner conductor.
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