Deflection yoke apparatus

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a deflection yoke 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 used with an in-line type CRT, 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 convergence or purity of a CRT by tuning a position of such the multipolar magnetic ring.

FIG. 8

is a perspective view for explaining an example of a deflection yoke for a CRT. In

FIG. 8

, the deflection yoke comprises a pair of separators

1

a

and

1

b

made by an insulating material, a pair of horizontal deflection coils (not shown) in inside of the deflection yoke, a pair of vertical deflection coils

7

on the outside of the deflection yoke, and a pair of cores

2

on the outer side of the vertical deflection coil

7

. A flange if 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

. A clamp band

5

with a screw

6

is loaded on the upper portion of the neck portion

103

to stabilize deflection yoke on to CRT.

FIG. 9

is a partial perspective view for explaining the example of the deflection yoke shown in FIG.

8

. In

FIG. 9

, the cylindrical neck portion

103

having tongues

103

a

through

103

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

104

a

through

104

f

. A clamp band

5

for fixing the deflection yoke to a neck of the CRT is provided on the upper side of the neck portion

103

. The 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

. A prominence

14

is formed on the upper portion of tongues

103

c

and

103

f

to fit with a pair of hole

5

a

and

5

b

formed in the clamp band

5

. The prominence

14

has a slope in downward direction for leading the holes

5

a

and

5

b

to make the clamp band

5

easily fit with the neck portion

103

. The clamp band

5

with a screw

6

is loaded on the upper portion of the neck portion

103

to stabilize the deflection yoke on to the CRT.

A magnetic ring

10

and a magnetic ring

11

having a multipolar magnet respectively are provided between the clamp band

5

and the flange

1

f

of the first and second separators

1

a

and

1

b

.

FIG. 9

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 material dispersed with magnetic powder such as barium ferrite or the Alnico alloy substance evenly on a nylon plastic. As the magnetic ring has variety in size at manufacturing, the inner diameter of the magnetic rings

10

and

11

is 0.4 mm wider at maximum than the outer diameter of the neck portion

103

, in order to avoid the magnetic ring being tightfitting with the neck portion

103

.

More precisely, protrusions

12

a

and

12

b

are provided at the bottom of the neck portion

103

, and are flexible in the longitudinal direction of the neck of the CRT (i.e. the direction of a Z axis). A hook

13

having a claw

13

a

of triangular shape at their distal ends are formed in the tongues

103

c

and

103

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

between the protrusions

12

a

and

12

b

, and the claw

13

a.

FIG. 10

is a cross-sectional view of the neck portion

103

along with the direction of the Z axis. An edge side

13

a

1

of the claw

13

a

is almost orthogonal with the Z axis and a sloped side

13

a

2

of the claw

13

a

stick out with length d

1

which is about 1.3 mm long enough to hold the magnetic ring being attached between the protrusions

12

a

and

12

b

, and the claw

13

a

. An outer side

13

a

3

of the claw

13

a

is provided to maintain the strength of metal mold for molding the separators

1

a

and

1

b

. The outer side

13

a

3

is almost parallel to the Z axis and has length of approximately 0.3 mm.

Recently, there has been a need for small display monitor using CRT in the market. In order to provide such a small display, the length of CRT and the deflection yoke is required to be shorter. For this reason, the distance between the bottom side of the clamp band

5

and the bottom side of magnetic rings attached to the neck portion

103

is required to be shorter, and the length of the claw

13

a

in the direction of Z axis is required to be 1.3 mm at maximum. Under circumstance, the length of each side of the claw

13

a

should be set to make slope angle θ of the slope side

13

a

2

bigger so that the magnetic rings can be easily attached to the neck portion

103

.

A slope side

13

a

2

s

is a start position of the slope for the slope side

13

a

2

. The slope side

13

a

2

s

is not set to the position coming out of the outer diameter side of the neck portion

103

but contiguous the outer diameter portion of the neck portion

103

. The slope angle θ, for example, is 32 degrees. The reason why the slope side

13

a

2

s

does not start from the inner diameter side of the neck portion

103

(and the reason why the claw

13

a

has the edge side

13

a

1

) is because the slope angle θ will be maximum at this position.

As the magnetic rings

10

and

11

are inserted to the neck portion

103

from the narrower diameter side of the deflection yoke, the magnetic rings

10

and

11

contact the prominence

14

and the neck portion

103

flex inwardly to let the magnetic rings

10

and

11

pass through the prominence

14

. Then the magnetic rings

10

and

11

contact the slope side

13

a

2

and the tongue

13

flex inwardly. Eventually, the magnetic rings

10

and

11

are held between the protrusions

12

a

and

12

b

, and the claw

13

a

. The distance between the protrusions

12

a

and

12

b

, and the claw

13

a

is lesser than the thickness of the magnetic rings

10

and

11

so that the bounce force of the protrusion

12

a

and

12

b

holds the magnetic rings

10

and

11

.

The adjustment of a characteristic of a magnetic field of CRT can be accomplished by putting a deflection yoke on the CRT and rotating the magnetic rings

10

and

11

. The magnetic rings can be rotate at an appropriate torque (not too tight or not too loose) by the protrusions

12

a

and

12

b

, and the claw

13

a

holding the magnetic rings

10

and

11

so that the magnetic rings

10

and

11

can not easily rotate before they are being fixed with a glue after the adjustment. This torque is also caused by the bounce force of the protrusions

12

a

and

12

b

in the direction of the Z axis.

FIG. 11

is a cross-sectional view of the tongues

103

f

and

103

c

of the neck portion

103

along with the direction of the Z axis where the magnetic ring

11

is being inserted. When the magnetic rings

10

and

11

is inserted in the neck portion

103

by hands, the magnetic ring

11

will occasionally be pushed to the direction shown as an arrow A in

FIG. 11

which is the direction orthogonal to the Z axis. Then the tongue

103

f

flexes inwardly from the position shown in a dotted line. At this position, the inner circumference side of the magnetic ring

11

contacts the edge side

13

a

1

of the claw

13

a.

This will cause the insertion of magnetic ring

11

to the neck portion

103

difficult. Too much strength to insert the magnetic ring

11

in the neck portion

103

at this position may break the magnetic rings

10

and

11

. As explained above, the magnetic rings

10

and

11

may break in the way of inserting.

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 apparatus including neck portion (

3

) in a cylindrical shape formed on a subterminal portion of a funnel shaped separator having a narrower diameter portion and a wider diameter portion, a magnetic ring (

10

,

11

,

20

and

21

) rotatably mounted on the neck portion (

3

), a holding portion (

33

a

,

33

b

) for holding the magnetic ring from the narrower diameter portion side; and a protrusion (

80

a

,

80

b

,

81

) formed on the neck portion having a first slope surface (

80

a

1

,

80

b

1

) decline to the outer direction from the narrower diameter portion side to the wider diameter portion side of the neck portion, wherein the magnetic ring contacts the first slope surface before contacting the holding portion when the magnetic ring is inserted to the neck portion from the narrower diameter portion side, and the protrusion leads the magnetic ring to the holding portion.

Other objects and further features of the present invention provides the deflection yoke as mentioned above, wherein the holding portion (

33

a

,

33

b

) has a second slope surface (

33

a

0

,

33

b

0

) decline to the outer direction from the narrower diameter portion side to the wider diameter portion side of the neck portion (

3

), and the first slope surface (

80

a

1

,

80

b

1

) of the protrusion leads the magnetic ring to the second slope surface of the holding portion.

Other objects and further features of the present invention provides the deflection yoke including neck portion (

3

) having a cylindrical shape and formed on a subterminal portion of a funnel shaped separator with a narrower diameter portion and a wider diameter portion, first protrusion (

14

) formed on the neck portion, clamp band (

5

) having a hole to fit with the first protrusion, for being attached to and for tightening up the neck portion, magnetic ring rotatably mounted on the wider diameter portion side of the neck portion than the position of the clamp band being attached to the neck portion, holding portion (

33

a

,

33

b

) for holding the magnetic ring from the narrower portion side; and second protrusion (

80

a

,

80

b

,

81

) having a slope surface decline to the outer direction from the narrower diameter portion side to the wider diameter portion side of the neck portion, and formed on the neck portion between the first protrusion and the holding portion, wherein the magnetic ring being inserted to the neck portion contacts the slope surface before contacting the holding portion.

A deflection yoke incorporating the principles of the present invention will be described in detail with reference to the accompanying drawings, in which the same reference numerals and symbols are used to denote like or equivalent elements used in the aforementioned prior art deflection yoke, and the detailed explanation of such elements are omitted for simplicity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1

is a perspective view of a deflection yoke according to a first embodiment of the present invention.

FIG. 2

is a partial perspective view of a deflection yoke shown in

FIG. 1

according to the present invention.

FIG. 3

is a partial perspective view of a substantial portion of a deflection yoke according to the first embodiment of the present invention.

FIG. 4

is a cross-sectional view of a substantial portion of a deflection yoke shown in FIG.

3

.

FIG. 5

is a cross-sectional view of a substantial portion of a deflection yoke for explaining a clamp band and a magnetic ring being inserted in a deflection yoke according to the present invention.

FIG. 6

is a cross-sectional view of a substantial portion of a deflection yoke for explaining an insertion of a magnetic ring to a deflection according to the present invention.

FIG. 7

is a partial perspective view of a substantial portion of a deflection yoke according to a second embodiment of the present invention.

FIG. 8

is a perspective view of a deflection yoke according to the prior art.

FIG. 9

is a partial perspective view of a deflection yoke according to the prior art.

FIG. 10

is a cross-sectional view of a deflection yoke for explaining the prior art.

FIG. 11

is a cross-sectional view of a deflection yoke for explaining the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[First Embodiment]

FIG. 1

is a perspective view of a deflection yoke according to the present invention. In

FIG. 1

, a deflection yoke for a CRT comprises a pair of separator

1

a

and

1

b

made by an insulating material to form an infundibular shape, a pair of horizontal deflection coils (not shown) in an inner side of the deflection yoke, a pair of vertical deflection coils

7

in outer side thereof, a pair of cores

2

in outer side of the vertical deflection coil

7

, a flange If on a minor diameter side of the separators

1

a

and

1

b

with a cylindrical neck portion

3

, forming on the flange

1

f

. There also provided a clamp band

5

on the neck portion

3

, and the clamp band

5

comprises a hole

5

a

in its ring portion and a screw

6

. The deflection yoke also comprises a pair of magnetic rings

10

and

11

and another pair of magnetic rings

20

and

21

to control the magnetic characteristic of the deflection yoke, and a spacer ring

22

between each pair of magnetic rings

10

,

11

and

20

,

21

.

FIG. 2

is a partial perspective view of the deflection yoke shown in

FIG. 1

according to the present invention. The neck portion

3

has a cylindrical shape with tongues

3

a

through

3

d

and is formed on the flange

1

f

with a pair of separators

1

a

and

1

b

. The neck portion

3

is not limited to have four tongues that it may have six tongues as described in the prior art and more or less. The neck portion

3

is flexible inwardly by a plural of slits

4

a

through

4

d

formed on thereof. The clamp band

5

is attached to the neck portion

3

to stabilize the deflection yoke on a neck portion of a CRT. The clamp band

5

has a hole

5

a

on its ring portion to fit with a prominence (not shown) formed on the side of neck portion

3

. The screw

6

tighten an inner circumference of the clamp band

5

as it screws to stabilize the deflection yoke on the neck portion of the CRT.

The magnetic rings

10

,

11

,

20

and

21

are attached to the neck portion

3

between the clamp band

5

and flange if with separators

1

a

and

1

b

. The spacer ring

22

is inserted unrotatablly between each pair of magnetic rings

10

,

11

and magnetic rings

20

,

21

to make each pair of magnetic rings rotate independently. The magnetic rings

10

,

11

,

20

and

21

comprise of material dispersed with magnetic powder such as barium ferrite or the Alnico alloy substance evenly on a nylon plastic. There provided an upper holding portions

33

a

0

and

33

b

0

, and holding portions

32

a

and

32

b

on the side of neck portion

3

to hold the magnetic rings

10

,

11

and

20

,

21

, and there also provided a protrusion

80

a

and

80

b

between the clamp band

5

and magnetic rings

10

and

11

. Z axis shown in

FIG. 2

is identical to the coaxial axis of the CRT to which the neck portion

3

is attached.

FIG. 3

is a partial perspective view of a substantial portion of a deflection yoke according to the first embodiment of the present invention. There provided holding portions

32

a

and

32

b

in the bottom portion of the center of neck portion

3

with tongues

3

d

and

3

c

. The holding portions

32

a

and

32

b

are formed in arm shape and flexible to the direction parallel to the Z axis. The edge portion of holding portion

32

a

has a protrusion

32

a

1

and the edge portion

32

b

has a protrusion

32

b

1

in the upward direction. There also provided a holding portion similar to the holding portions

32

a

and

32

b

in the opposite side of the neck portion

3

with tongues

3

a

and

3

b.

The neck portion

3

comprises L-shaped upper holding portions

33

a

and

33

b

. The upper holding portions

33

a

and

33

b

are connected with tongues

3

c

and

3

d

, and they are substantially independent portions. The upper holding portions

33

a

and

33

b

have substantially the same function of the tongue

13

shown in FIG.

9

. The edge portion of each upper holding portion

33

a

and

33

b

has claw shaped protrusions

33

a

0

and

33

b

0

. The protrusions

33

a

0

and

33

b

0

have edge surface

33

a

1

and

33

b

1

respectively, which surface is orthogonal with the Z axis. Slope surfaces

33

a

2

and

33

b

2

are the prominent surface of the upper holding portions

33

a

and

33

b

in outer side of the neck portion

3

, and each surface

33

a

4

of the protrusion

33

a

0

and surface

34

b

4

of the protrusion

33

b

0

is opposed to the holding portions

32

a

and

32

b

respectively, each of which is orthogonal with the Z axis. The slope surfaces

33

a

2

and

33

b

2

have a downslope from the edge surface

33

a

1

and

33

b

1

towards the direction of holding portions

32

a

and

32

b

. More precisely, the slope surfaces

33

a

2

and

33

b

2

decline to the outer side towards the direction of the narrower diameter portion of the infundibular shaped deflection yoke to the wider diameter portion thereof.

The upper holding portions

33

a

and

33

b

, except for the protrusions

33

a

0

and

33

b

0

, are placed in substantially the same circumference of the neck portion

3

, There also provided an upper holding portion similar to the upper holding portion

33

a

and

33

b

on the opposite side of the tongues

3

d

and

3

c

. The upper holding portions

33

a

and

33

b

, and the holding portions

32

a

and

32

b

hold the magnetic rings

10

,

11

,

20

and

21

.

In

FIG. 3

, there are provided protrusions

80

a

and

80

b

with rib shape on the tongues

3

c

and

3

d

. There is also provided a rib shaped protrusion similar to the protrusions

80

a

and

80

b

on each of the tongues

3

a

and

3

b

. The protrusions

80

a

and

80

b

are formed on positions lower (i.e. the wider diameter portion) than the upper position where the clamp band

5

is clamped to the neck portion

3

, and contiguous to the protrusion

33

a

0

and

33

b

0

.

Each protrusion

80

a

and

80

b

has a slope surface

80

a

1

and

80

b

1

of which slope starts from a position

80

a

1

s

and

80

b

1

s

respectively, and inclines to the outer side towards the direction of the holding portions

32

a

and

32

b

. Each slope surface

80

a

1

and

80

b

1

is connected with an outer surface

80

a

2

and

80

b

2

respectively, and side surfaces

80

a

3

and

80

b

3

are connected with the outer surfaces

80

a

2

and

80

b

2

respectively, in the position opposed to the holding portion

32

a

and

32

b.

FIG. 4

is a cross-sectional view of the tongues

3

a

and

3

b

of the neck portion

3

towards the direction parallel to the Z axis. The protrusions

80

a

and

80

b

are formed above the protrusions

33

a

0

and

33

b

0

of the upper holding portions

33

a

and

33

b

as also shown in FIG.

3

.

FIG. 5

is a cross-sectional view of the tongues

3

a

and

3

d

of the neck portion

3

shown in

FIG. 4

where the clamp band

5

and the magnetic rings

10

and

11

are inserted on the neck portion

3

. In

FIG. 5

, the bottom portion side of the clamp band

5

abuts edges

80

a

1

s

and

80

b

1

s

when the clamp band

5

is inserted in the neck portion

3

. The slope

80

a

1

and

80

b

1

are formed in higher positions than the slope surfaces

33

a

2

and

33

b

2

.

The protrusions

80

a

and

80

b

should be in a position where the slope surfaces

80

a

1

and

80

b

1

contact the magnetic rings

10

and

11

before they contact the slope surfaces

33

a

2

and

33

b

2

of the protrusions

33

a

0

and

33

b

0

when they are inserted in the neck portion.

The magnetic rings

10

and

11

should be held by the upper holding portions

32

a

and

32

b

, and the holding portions

33

a

and

33

b

. Accordingly, the side surfaces

80

a

3

and

80

b

3

, and the surfaces

33

a

4

and

34

b

4

should be in the same surface orthogonal to the Z axis or the side surfaces

80

a

3

and

80

b

3

should be in the position nearer to the narrower diameter portion side of the deflection yoke than the surfaces

33

a

4

and

33

b

4

.

The outer side surfaces

80

a

2

and

80

b

2

are formed in the same circumference and the outer side of protrusions

33

a

0

and

33

b

0

are formed in the same circumference. The diameter of circumference for the outer side surfaces

80

a

2

and

80

b

2

is shorter than the diameter of circumference for the outer side of protrusions

33

a

0

and

33

b

0

. The diameter of circumference for the outer side surfaces

80

a

2

and

80

b

2

is bigger than the inner circumference of the magnetic rings

10

,

11

,

20

and

21

.

FIG. 6

is a cross-sectional view of a substantial portion of a deflection yoke for explaining an insertion of a magnetic ring to a deflection yoke according to the present invention. As the magnetic ring

11

is inserted to the neck portion

3

, the magnetic ring

11

passes through the prominence

14

(not shown in

FIG. 6

) and comes to the position shown in FIG.

6

. As the inner circumference of the magnetic ring

11

is shorter than the circumference of the outer side surfaces

80

a

2

and

80

b

2

, the magnetic ring

11

contacts the slope surfaces

80

a

1

and

80

b

1

. As the magnetic ring

11

moves to the direction D (shown as an arrow D), the tongues

3

c

and

3

d

(and tongues

3

a

and

3

b

) flex inwardly (to the direction shown as an arrow C) from the position shown in a dotted line to the position shown in a solid line. As the tongues

3

a

through

3

d

flex equally, the position of the magnetic ring

11

is set on the center of the neck portion

3

. The insertion of the magnetic rings

10

,

20

and

21

operates in exactly same manner.

As the magnetic ring

11

is inserted towards the direction D, the magnetic ring

11

contact the protrusions

80

a

and

80

b

, and then contact the slope sides

33

a

2

and

33

b

2

. As the magnetic ring

11

is further inserted to the direction D, the holding portions

33

a

and

33

b

flex inwardly to the direction C, and it overcomes the protrusions

33

a

0

and

33

b

0

. Consequently, the magnetic ring

11

is inserted between the protrusions

33

a

0

and

33

b

0

of the upper holding portions

33

a

and

33

b

, and the holding portions

32

a

and

32

b.

The magnetic rings

10

,

20

and

21

are inserted to the neck portion

3

as described above. As the pushing force is added to the neck portion

3

to the direction C, the bounce force pushes back the protrusions

80

a

and

80

b

to keep the center of magnetic rings

10

,

11

,

20

and

21

in the coaxial center of the neck portion

3

. Further, the protrusions

80

a

and

80

b

induce the magnetic rings to contact the slope side

33

a

2

and

33

b

2

of the upper holding portions

33

a

and

33

b.

Consequently, even when the tongues

3

a

through

3

d

flex, the magnetic rings

10

,

11

,

20

and

21

do not contact the edge surfaces

33

a

1

and

33

b

1

of the upper holding portions

33

a

and

33

b

, but contact the edge surfaces

33

a

4

and

33

b

4

. This is a simple and easy way to attach the magnetic rings

10

,

11

,

20

and

21

on the neck portion

3

. In addition, the magnetic rings

10

,

11

,

20

and

21

will not break since they do not contact the edge surfaces

33

a

1

and

33

b

1

.

Further more, the protrusions

80

a

and

80

b

induce the clamp band

5

to the appropriate position and restrict the position towards the direction of the Z axis. Even if the clamp band

5

contact the slope surfaces

80

a

1

and

80

b

1

before tightening up the bolt

6

, the clamp band

5

will slip the slope surfaces

80

a

1

and

80

b

1

to the direction towards the neck as the bolt

6

is being tightening up. Eventually, the clamp band

5

is induced to the position

80

a

1

s

and

80

b

1

s

as shown in FIG.

5

.

In addition, as the clamp band

5

does not contact the protrusions

33

a

0

,

33

b

0

when the clamp band

5

is tightened up, the slope angle of the slope sides

33

a

2

and

33

b

2

(equivalent to the slope angle θ shown in

FIG. 10

) can be increased to make the insertion of the magnetic rings

10

,

11

,

20

and

21

easier.

The present invention is not limited to the embodiment described above and can be modified in various ways. The protrusions

80

a

and

80

b

can be formed in any place as long as the physical relationship between the protrusion

80

a

and

80

b

, and the protrusions

33

a

0

and

33

b

0

in the direction of the Z axis is the same as the first embodiment. However, it is preferable that the position of the protrusions

80

a

and

80

b

are formed contiguous the protrusions

33

a

0

and

33

b

0

. The slope sides

80

a

1

and

80

b

1

may not necessarily be flat. They can be curved surface as long as they help the insertion of the magnetic rings

10

,

11

,

20

and

21

easier. The other sides of the protrusions

80

a

and

80

b

are not necessarily flat that the edge line can be rounded off which is preferable for the purpose of molding the neck portion

3

. The number of the protrusions

80

a

and

80

b

is not limited to two which is same as the number of the upper holding portions

33

a

and

33

b

in this embodiment. There can be more than two protrusions

80

a

and

80

b

formed in the neck portion

3

.

[Second Embodiment]

FIG. 7

is a partial perspective view of a substantial portion of a deflection yoke for second embodiment according to the present invention. In

FIG. 7

, a circular protrusion

81

is formed on the neck portion

3

in the direction of circumference. The circular protrusion

81

is equivalent to the protrusions

80

a

and

80

b

shown in

FIG. 3

formed continuously around the neck portion

3

. In this sense, the cross-sectional view of the circular protrusion

81

in the direction parallel to the Z axis is the same as the cross-sectional view of the protrusion

80

a

or protrusion

80

b

in the direction parallel to the Z axis. Although it is not shown, the protrusion can also be an arc shape.

The first embodiment above describes that the upper holding portions

33

a

and

33

b

, and the holding portions

32

a

and

32

b

are formed in two pairs in one side of the neck portion

3

but there can be only one pair of the upper holding portion and the holding portion. The magnetic rings

10

,

11

,

20

and

21

to be inserted on the neck portion

3

are not limited to be four (4) and could be more or less. The present invention is not limited to the above embodiments and can be modified within the scope of the purpose of the present invention.

According to an aspect of the present invention, there provided a deflection yoke having a protrusion on a neck portion of the deflection yoke where such protrusion has a slope surface decline to the outer direction from the narrower diameter side to the wider diameter side of the deflection yoke, and contacts a magnetic ring being inserted to the neck portion from the narrower diameter side before the magnetic ring contacts holding portion, and the magnetic ring is held by the holding portion wherein the magnetic ring contacts a second protrusion and the holding portion, and the second protrusion is formed between a first protrusion to stable a clamp band and the holding portion formed on the neck portion, to easily insert the magnetic ring on the neck portion and to avoid the magnetic ring from being damaged.

Deflection yoke apparatus

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Term Extension

Abstract

Description

Claims

Priority Claims (1)