Deflection yoke with inflexible holding part

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 and said inflexible holding means are formed in identical position of circular direction of said neck 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 common to all embodiments according to the present invention.

FIG. 2

is a partial perspective view of a deflection yoke shown in

FIG. 1

according to a first embodiment of the present invention.

FIG. 3

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

FIG. 4

is an enlarged view of a substantial portion of a deflection yoke shown in

FIGS. 2 and 3

.

FIG. 5

is a cross-sectional view taken substantially along X and Y axis of

FIG. 3

for explaining an operation of a deflection yoke according to the present invention.

FIG. 6

is a cross-sectional view of a magnetic ring taken substantially along X and Y axis of

FIG. 3

for a deflection yoke according to the present invention.

FIG. 7

is for explaining an operation of a magnetic ring for a deflection yoke shown in

FIG. 6

according to the present invention.

FIG. 8

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

FIG. 9

is an enlarged view of a substantial portion of a third embodiment of a deflection yoke according to the present invention.

FIG. 10

is an enlarged view of a substantial portion of a fourth embodiment of a deflection yoke according to the present invention.

FIG. 11

is a perspective view for explaining an example of a deflection yoke for a cathode ray tube according to the prior art.

FIG. 12

is a partial perspective view for explaining an example of a deflection yoke shown in

FIG. 11

for a cathode ray tube according to 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, 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

1

f

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

, a clamp band

5

to fix a deflection yoke to a neck of the CRT, a screw

6

to fasten deflection yoke to the neck of CRT by tightening the clamp band

5

about the neck portion

3

, and a pair of magnetic rings

10

and

11

to control magnetic characteristic of a deflection yoke.

The neck portion

3

is formed on the flange

1

f

with a pair of separators

1

a

and

1

b

. The neck portion

3

is flexible inwardly by a plural of slits

4

a

through

4

f

formed on the neck portion

3

. 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

is screwed with a bolt

6

to tighten an inner circumference of the clamp band

5

to stabilize the deflection yoke on the neck portion of the CRT.

FIG. 2

is a partial perspective view of substantial portion of a deflection yoke shown in

FIG. 1

according to the present invention, in which a flange

1

f

with a clamp band

5

, and a pair of magnetic rings

10

and

11

attached onto a neck portion

3

. A pair of multipolar magnetic rings

10

and

11

are attached between the clamp band

5

and the pair of the separators

1

a

and

1

b

, of the flange

1

f

by a head portion

33

a

1

of a holding portion

32

a

and a head portion

33

b

1

of a holding portion

32

b

, and by a head portion not shown but formed on the upper holding portions

33

a

and

33

b

. Generally, the pair of magnetic rings

10

and

11

comprises material dispersed with magnetic powder such as Barium ferrite or Alnico alloy substance evenly on a nylon plastic.

FIG. 3

is a partial perspective view of substantial portion of a deflection yoke shown in

FIG. 1

according to the present invention, wherein the clamp band

5

and the pair of magnetic rings

10

and

11

removed from the neck portion

3

in comparison with

FIG. 2. A

holding portion

32

a

and a holding portion

32

b

are formed on the flange

1

f

with brachial shape, and they can flexibly bend to the direction of Z axis or the longitudinal direction of the neck of the CRT. There formed a protuberance

32

a

1

and a protuberance

32

b

1

in the head portion of the holding portions

32

a

and

32

b

respectively. Each holding portion

32

a

and

32

b

is placed on the outer side of the neck portion

3

to hold a tongue

3

d

. There formed a pair of protrusions, which is not visible in

FIG. 3

, symmetric to the holding portions

32

a

and

32

b

behind the tongue

3

a

to hold the tongue

3

a.

On the flange

1

f

, there formed an ell shaped upper holding portions

33

a

and

33

b

. There formed a protuberance

33

a

1

and a protuberance

33

b

1

in the head portion of the holding portions

32

a

and

32

b

respectively. Each protuberance

33

a

1

and

33

b

1

is inclined from the narrower to the wider diameter direction as the raised portion extends to the outer direction. The upper holding portions

33

a

and

33

b

, and the tongues

3

a

through

3

f

are placed on the same circumference surface surrounding the tongues

3

a

and

3

b

. Each protuberance

32

a

1

and

32

b

1

of the holding portion

32

a

and

32

b

opposes to each protuberance

33

a

1

and

33

b

1

of the upper holding portion

33

a

and

33

b

. The holding portion

32

a

and the upper holding portion

33

a

, and the holding portion

32

b

and the upper holding portion

33

b

hold the magnetic rings

10

and

11

as shown in FIG.

2

.

FIG. 4

is an enlarged view of the upper holding portion

33

a

which is a substantial portion of a deflection yoke, according to the present invention. The upper holding portion

33

b

has symmetric shape of the upper holding portion

33

a

and substantially has the same functionality of the upper holding portion

33

a

. Accordingly,

FIG. 4

shows only the upper holding portion

33

a

for explanation. The upper holding portion

33

a

comprises a protuberance

33

a

1

in a head portion

33

a

2

, and a root portion

33

a

3

to combine with the flange

1

f

, and an intermediate portion

33

a

4

to connect the head portion

33

a

2

with the root portion

33

a

3

. The upper holding portion

33

b

also comprises a head portion

33

b

2

with a protuberance

33

b

1

, a root portion

33

b

3

to combine with the flange

1

f

, and an intermediate portion

33

b

4

to connect the head portion

33

b

2

with the root portion

33

b

3

.

FIG. 5

is a cross-sectional view of the neck portion

3

shown in

FIG. 3

in orthogonal direction of Z axis for explaining an operation of a deflection yoke according to the present invention. In

FIG. 5

, X is a horizontal axis for the deflection yoke being attached to the CRT, and Y is a vertical axis for the same. As shown in

FIG. 5

, the upper holding portions

33

a

and

33

b

, and the tongues

3

a

through

3

f

of the neck portion

3

are formed in the same circle face except for the protuberances

33

a

1

and

33

b

1

.

FIG. 6

is a cross-sectional view of a magnetic ring

10

attached to the neck portion

3

of the deflection yoke according to the present invention. The magnetic ring

11

can also be attached to the neck portion

3

of the deflection yoke as shown in FIG.

6

. The magnetic ring

10

is inserted from the narrower diameter side of the neck portion

3

, and pushes the protuberances

33

a

1

and

33

b

1

to the inner side of the neck portion

3

. The protrusions

33

a

and

33

b

are formed on the flange

1

f

, and have flexibility so that the head portions

33

a

2

and

33

b

2

can inwardly flex.

However, the upper holding portions

33

a

and

33

b

are different from the tongue

13

as shown in

FIG. 12

that they have a root portion

33

a

3

and a root portion

33

b

3

in a distant place from the protuberances

33

a

1

and

33

b

1

in circle direction. Accordingly, the root portions

33

a

3

and

33

b

3

are inflexible. The intermediate portion

33

a

4

and

33

b

4

is little more flexible than this and the head portions

33

a

3

and

33

b

2

are inwardly flexible. The magnetic rings

10

and

11

are attached between the holding portions

32

a

and

32

b

, and the protuberances

33

a

1

and

33

b

1

by the head portions

33

a

2

and

33

b

2

inwardly flexed.

The root portions

33

a

3

and

33

b

3

will be inflexible even the thickness of the head portions

33

a

2

and

33

b

2

to the root portion

33

a

3

and

33

b

3

is constant respectively. It is more favorable

1

f

the thickness of each root portions

33

a

3

and

33

b

3

is bigger than the intermediate portions

33

a

4

and

33

b

4

so that the root portions

33

a

3

and

33

b

3

will be even more inflexible.

FIG. 7

is for explaining an operation of a magnetic ring for a deflection yoke shown in

FIG. 6

according to the present invention. As a screw

6

is screwed to tighten the clamp band

5

and fasten the neck portion

3

, the tongues

3

a

through

3

f

are inwardly flexed (to the direction of the arrows shown in FIG.

7

), and the inner circumference of the neck portion becomes smaller than that of the magnetic rings

10

and

11

. In this sense, The holding portions

33

a

and

33

b

, and the tongues

3

a

through

3

f

independently hold the magnetic rings

10

and

11

.

Even if the magnetic rings

10

and

11

, or the upper holding portions

33

a

and

33

b

are pushed inwardly to the radial direction, at the tuning or after the tuning of the magnetic rings

10

and

11

, the root portions

33

a

3

and

33

b

3

are inflexible so that the root portions

33

a

3

and

33

b

3

hold the magnetic rings

10

and

11

. Accordingly, the protuberances

33

a

1

and

33

b

1

still hold the magnetic rings

10

and

11

.

Second Embodiment

FIG. 8

is an enlarged view of a substantial portion of a second embodiment of a deflection yoke according to the present invention. In

FIG. 8

, an upper holding portion

43

a

can be a substitution for the upper holding portion

33

a

, and the upper holding portion

43

a

comprises a first tongue

43

a

2

having a protuberance

43

a

1

and a second tongue

43

a

3

. The first tongue

43

a

2

and the second tongue

43

a

3

are substantially separated from each other by a slit

43

a

4

. A substitution for the protrusion

33

b

will be referred to as a upper holding portion

43

b

which is not shown in FIG.

8

. The upper holding portion

43

b

has a symmetrical shape of the upper holding portion

43

a

and comprises of a first tongue

43

b

2

having a protuberance

43

b

1

, and a second tongue

43

a

3

, and a slit

43

b

4

.

The first tongues

43

a

2

and

43

b

2

are flexible inwardly, and the second tongues

43

a

3

and

43

b

3

are substantially inflexible. The first tongues

43

a

2

and

43

b

2

, and the second tongues

43

a

3

and

43

b

3

can be separated completely. As shown in

FIG. 8

, the root portion of the first tongues

43

a

2

and

43

b

2

, and the second tongues

43

a

3

and

43

b

3

are connected with each other but there provided the slits

43

a

4

and

43

b

4

respectively that the first tongues

43

a

2

and

43

b

2

, and the second tongues

43

a

3

and

43

b

3

, which are substantially separated, are all equal in this embodiment of the present invention. The upper holding portions

43

a

and

43

b

having inflexible second tongues

43

a

3

and

43

b

3

to restrict the position of inner circumference surface of the magnetic rings

10

and

11

in a distant place of the first tongues

43

a

2

and

43

b

2

having the protuberances

43

a

1

and

43

b

1

.

Third Embodiment

FIG. 9

is an enlarged view of a substantial portion of a third embodiment of a deflection yoke according to the present invention. In

FIG. 9

, a upper holding portion

53

a

is a substitution of the upper holding portion

33

a

. The upper holding portion

53

a

comprises a head portion

53

a

2

having a claw shaped protuberance

53

a

1

, a root-portion

53

a

3

combining with the flange

1

f

, an intermediate portion

53

a

4

connecting the head portion

53

a

2

with the root portion

53

a

3

. The upper holding portion

53

a

is similar to the ell shaped upper holding portions

33

a

and

33

b

shown in

FIG. 4

that the flexible portion and the inflexible portion is combined in one piece. An upper holding portion

53

b

is not shown in

FIG. 9

but it has a symmetric shape of the upper holding portion

53

a

. The upper holding portion

53

b

not shown in

FIG. 9

has a protuberance

53

b

1

, a head portion

53

b

2

, a root portion

53

b

3

and an intermediate portion

53

b

4

. The intermediate portions

53

a

4

and

53

b

4

in this embodiment are thicker than the other portions of the upper holding portions

53

a

and

53

b.

As the magnetic rings

10

and

11

are inserted in the neck portion

3

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

10

and

11

climb over the protuberances

53

a

1

and

53

b

1

, and the inner circumference surface of the magnetic rings

10

and

11

substantially touch the root portions

53

a

3

and

53

b

3

. In this situation, the head portions

53

a

2

and

53

b

2

will be flexible, and the root portions

53

a

3

and

53

b

3

, and the intermediate portions

53

a

4

and

53

b

4

will be inflexible. The root portions

53

a

3

and

53

b

3

, and the intermediate portions

53

a

4

and

53

b

4

will hold the position of the inner circumference surface of the magnetic rings

10

and

11

, and prevent the rings from disengaged from such position.

The flexible portion such as the head portions

53

a

2

and

53

b

2

, and the intermediate portions

53

a

4

and

53

b

4

, and the inflexible portion such as the root portions

53

a

3

and

53

b

3

shown in

FIG. 9

are formed in the same circular direction. The head portions

53

a

2

and

53

b

2

are more flexible inwardly. The flexible portion and the inflexible portion can be formed in the same circular direction.

Fourth Embodiment

FIG. 10

is an enlarged view of a substantial portion of a fourth embodiment of a deflection yoke according to the present invention.

FIG. 10

shows an upper holding portion

63

a

which is a substitution of the upper holding portion

33

a

shown in

FIG. 4

, having a first tongue

63

a

2

with a claw shaped protuberance

63

a

1

in the head portion, and having a second tongue

63

a

3

hollowed out of the first tongue

63

a

2

. The first tongue

63

a

2

and the second tongue

63

a

3

is substantially separated by an opposite oxbow shaped slit

63

a

4

. An upper holding portion

63

b

not shown in

FIG. 10

has symmetric shape of the upper holding portion

63

a

, and it has a protuberance

63

b

1

, a first and second tongues

63

b

2

and

63

b

3

, and an opposite oxbow shaped slit

63

b

4

.

The first tongues

63

a

2

and

63

b

2

are flexible inwardly to the neck portion

3

, and the second tongues

63

a

3

and

63

b

3

are inflexible. The first tongues

63

a

2

and

63

b

2

, and the second tongues

63

a

3

and

63

b

3

can be separated substantially. The first tongue

63

a

2

and the second tongue

63

a

3

, and the first tongue

63

b

2

, and the second tongue

63

b

3

are connected with each other by the root portion respectively, but each first and second tongue is substantially separated by the slit

63

a

4

and

63

b

4

. The holding portions

63

a

and

63

b

having the first tongues

63

a

2

and

63

b

2

with the protuberances

63

a

1

and

63

b

1

, and having inflexible portion of the second tongues

63

a

3

and

63

b

3

in the same circular direction hold position of the inner circumference surface of the magnetic rings

10

and

11

.

Each embodiment of the present invention as explained above have the protuberances

33

a

1

,

33

b

1

,

43

a

1

,

43

b

1

,

53

a

1

,

53

b

1

,

63

a

1

and

63

b

1

as being formed flexible, which can easily attach the magnetic rings

10

and

11

on to the neck portion

3

. After the magnetic rings

10

and

11

are attached to the neck portion

3

, the inflexible portion such as the root portion

33

a

3

and

33

b

3

, the second tongue

43

a

3

and

43

b

3

, the root portion

53

a

3

and

53

b

3

, and the second tongue

63

a

3

and

63

b

3

can hold the position of the inner circumference surface of the magnetic rings

10

and

11

. Accordingly, the magnetic rings

10

and

11

can not be disengaged from the neck portion

3

. Additionally, the inflexible portion in accordance with the above explanation may be in actual contact with the magnetic rings

10

and

11

, but they may also be in a position contiguous and not in actual contact with each other.

The position of the upper holding portions

33

a

,

33

b

,

43

a

,

43

b

,

53

a

,

53

b

,

63

a

and

63

b

, i.e. the position of the upward protuberance

33

a

1

,

33

b

1

,

43

a

1

,

43

b

1

,

53

a

1

,

53

b

1

,

63

a

1

and

63

b

1

, and the position of the holding portions

32

a

and

32

b

, i.e. downward protrusions are opposed to each other. Accordingly, even

1

f

the magnetic rings

10

and

11

have an awkward or a curved shape, the rotation torque of the magnetic rings

10

and

11

can be constant and stable so that the convergence is effectively adjusted by rotating the magnetic rings

10

and

11

. It is preferable to keep an upward holding portion and a downward holding portion opposed to each other to hold a magnetic ring.

While the invention has been described above with reference to specific embodiment, the present invention is not limited to the embodiments explained herein. For example, there provided two pairs of holding portions in one side of the neck portion

3

which holds the magnetic rings

10

and

11

, but there also can be one pair of holding portion. Additionally, a magnetic ring attached to the neck portion

3

is not limited to number of two that there also can be single magnetic ring or more than three magnetic rings as well.

According to an aspect of the present invention, there provided a deflection yoke having a substantially inflexible portion which portion substantially touches the inner circle surface of a magnetic ring to restrict the position of such magnetic ring, so that the magnetic ring can be easily attached to a neck portion of a deflection yoke, and that the ring can not unexpectedly disengaged from the neck portion.

Deflection yoke with inflexible holding part

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)