Electric lamp and discharge devices – Cathode ray tube – Beam deflecting means
Reexamination Certificate
2001-02-16
2002-10-29
Patel, Vip (Department: 2879)
Electric lamp and discharge devices
Cathode ray tube
Beam deflecting means
C335S210000, C335S212000
Reexamination Certificate
active
06472809
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a deflection yoke, which is used with an in-line type cathode ray tube (CRT), and particularly relates to a deflection yoke for adjusting a characteristic of a magnetic field, such as convergence or purity, by rotating a multipolar magnetic ring mounted on a cylindrical neck portion of such deflection yoke.
2. Description of the Related Art
Generally, a deflection yoke, which is used with an in-line type CRT (cathode ray tube), has a multipolar, for example, dipole or quadrupole magnetic ring. The multipolar magnetic ring is used for adjustment of a magnetic field characteristic such as the convergence or the purity of CRT by tuning a position of such multipolar magnetic ring.
FIG. 11
is a perspective view for explaining an example of a deflection yoke for a CRT. In
FIG. 11
, the deflection yoke for a CRT comprises a pair of separators
1
a
and
1
b
made by an insulating material on the narrower diameter portion of the deflection yoke, a pair of horizontal deflection coils (not shown) in inside of the deflection yoke, and a pair of vertical deflection coils
7
on the outside and the wider diameter portion of the deflection yoke, and a pair of cores
2
on the outer side of the vertical deflection coil
7
, a flange
1
f
is formed in a narrower diameter side of the first separator
1
a
and the second separator
1
b
, and a cylindrical neck portion
103
is formed in the flange
1
f.
FIG. 12
is a partial perspective view for explaining the example of the deflection yoke shown in
FIG. 11
for a CRT. In
FIG. 12
, the cylindrical neck portion
103
having tongues
3
a
through
3
f
, is formed on a flange
1
f
with the first and second separators
1
a
and
1
b.
The cylindrical neck portion
103
is inwardly flexible as it has slits
4
a
through
4
f
. A clamp band
5
for fixing the deflection yoke to a neck of the CRT is provided on the neck portion
103
. A screw
6
is screwed to the clamp band
5
, and fastens the deflection yoke to the neck of the CRT by tightening the clamp band
5
about the neck portion
103
.
Each magnetic ring
10
and
11
has multipolar magnet and is provided between the clamp band
5
and the flange
1
f
of the first and second separators
1
a
and
1
b
.
FIG. 12
shows the clamp band
5
and the magnetic rings
10
and
11
being removed from the neck portion
103
. Generally, the magnetic rings
10
and
11
comprise of material dispersed with magnetic powder such as Barium ferrite or Alnico alloy substance evenly on a nylon plastic. The inner diameter of the magnetic rings
10
and
11
is nearly equal to the outer diameter of the neck portion
103
.
More precisely, protrusions
12
a
and
12
b
are flexible in the direction of the Z axis or the longitudinal direction of the neck of the CRT, and are provided at the bottom of the neck portion
103
. A hook
13
having a claw
13
a
of triangular shape at their distal ends are formed on the tongues
3
c
and
3
f
of the neck portion
103
. The magnetic rings
10
and
11
are inserted from the rear side of the deflection yoke, about the neck portion
103
having a cylindrical shape, between the protrusions
12
a
and
12
b
, and the claw
13
a.
A prominence
14
is formed on the upper area of the tongues
3
c
and
3
f
for engaging with holes
5
a
and
5
b
of the clamp band
5
respectively. The prominence
14
is sloped away from the neck portion
103
and toward the bottom thereof. As. the hook
13
, is flexible, the magnetic rings
10
and
11
are easily set to a predetermined position of the neck portion
103
. The distance between the protrusions
12
a
and
12
b
, and the claw
13
a
is shorter than the thickness of the magnetic rings
10
and
11
put together, so that a bounce force of the protrusions
12
a
and
12
b
is applied on the magnetic rings
10
and
11
when such rings are inserted between the protrusions
10
and
11
, and the claw
13
a.
A deflection yoke is attached to a CRT to control magnetic filed characteristic such as convergence, and such control is performed by rotating the position of magnetic rings
10
and
11
. An adequate (rotational) torque is added for tuning position of the magnetic rings
10
and
11
by the protrusions
12
a
and
12
b
, and the claw
13
a
, so that the magnetic rings
10
and
11
may not loosely rotate after the tuning and until a glue fixes the appropriate position of the magnetic rings
10
and
11
. The rotating torque is obtained by a frictional force occurred by a bounce force of the protrusions
12
a
and
12
b
in upward direction of Z axis in FIG.
12
.
According to the above prior art mentioned, a width of a slit between the tongues
3
a
through
3
f
and the pair of magnetic rings
10
and
11
becomes bigger as the neck portion
103
becomes narrower by tighten a bolt
6
to make inner circle of the clamp band
5
smaller. A neck portion of the CRT has a variation of the thickness, and the width of a slit between the tongues
3
a
through
3
f
and the pair of magnetic rings
10
and
11
becomes more bigger when the deflection yoke is attached to the neck portion, which has thinner circle. As a result, a pair of tongues
13
holds the pair of the magnetic rings
10
and
11
from the inner circumference of the magnetic ring in the radial direction.
However, the tongues
13
is flexible inwardly to the neck portion
103
as a inward force pushes one of the tongues
13
at the tuning of the magnetic rings
10
and
11
that the magnetic rings
10
and
11
are released from the tongue
13
. Then the magnetic rings
10
and
11
are disengaged from the attached position between the protrusions
12
a
and
12
b
, and the claw
13
a.
SUMMARY OF THE INVENTION
Accordingly, in consideration of the above-mentioned problem of the related art, an object of the present invention is to provide a deflection yoke of which a magnetic ring is attached to the neck portion, to control convergence by tuning such magnetic ring, and which can prevent a magnetic ring from being disengaged from a neck portion without losing smooth attachment to the neck portion.
In order to achieve the above object, the present invention provides, according to an aspect thereof, a deflection yoke for a cathode ray tube comprising: separator means in a funnel shape having a narrower diameter portion and a wider diameter portion, wherein a neck portion in a cylindrical shape is formed on said narrower diameter portion; magnetic ring means rotatably mounted on said neck portion; holding means having at least a pair of holding portions for holding said magnetic ring means from said narrower diameter portion side and said wider diameter portion side respectively, wherein said holding portion of narrower diameter portion side has an inwardly flexible portion; and inflexible holding means having a substantially inflexible portion for restricting position of said magnetic ring means where said inflexible holding means substantially contacts the inner circumference surface of said magnetic ring means after said magnetic ring means is attached to thereto.
Other objects and further features of the present invention provides the deflection yoke as mentioned above, wherein said inflexible holding means is combined with said flexible holding means, and wherein said flexible holding means and said inflexible holding means are formed in distant position on circular direction of said neck portion.
Other object and further features of the present invention provides the deflection yoke as mentioned above, wherein said inflexible holding means is formed separately with said flexible holding means, and wherein said flexible holding means and said inflexible holding means are formed in distant position on circular direction of said neck portion.
Other object and further features of the present invention provides the deflection yoke as mentioned above, wherein said inflexible holding means is formed separately with said flexible holding means, and wherein said flexible holding means
Morimoto Keiji
Motomiya Yoji
Connolly Bove & Lodge & Hutz LLP
Patel Vip
Victor Company of Japan Ltd.
LandOfFree
Deflection yoke with inflexible holding part does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Deflection yoke with inflexible holding part, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Deflection yoke with inflexible holding part will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2999950