Abstract:
A deflection yoke for a cathode ray tube comprises a funnel shaped separator means  1   a,    1   b  having a cylindrical neck portion  3  where a magnetic ring is attached. The magnetic ring is engaged with upward holding portions  33   a,    33   b  and with downward holding portions  32   a,    32   b,  which hold such magnetic ring. Root portions  33   a   3  and  33   b   3  of the downward holding portions  32   a  and  32   b  are substantially inflexible, where the inner circumference of the magnetic ring substantially contacts the root portions  33   a   3  and  33   b   3,  and the root portions  33   a   3  and  33   b   3  restrict the position of magnetic ring from being disengaged from the protrusions  33   a   1  and  33   b   1  when the downward holding portions  33   a  and  33   b  are forced to disengage the magnetic ring.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    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.  
           [0003]    2. Description of the Related Art  
           [0004]    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.  
           [0005]    [0005]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.    
           [0006]    [0006]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.    
           [0007]    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 .  
           [0008]    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 .  
           [0009]    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.    
           [0010]    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.    
           [0011]    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.  
           [0012]    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.  
           [0013]    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  
         [0014]    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.  
           [0015]    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.  
           [0016]    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.  
           [0017]    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.  
           [0018]    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.  
           [0019]    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  
       [0020]    [0020]FIG. 1 is a perspective view of a deflection yoke common to all embodiments according to the present invention.  
         [0021]    [0021]FIG. 2 is a partial perspective view of a deflection yoke shown in FIG. 1 according to a first embodiment of the present invention.  
         [0022]    [0022]FIG. 3 is a partial perspective view of a deflection yoke according to the first embodiment of the present invention.  
         [0023]    [0023]FIG. 4 is an enlarged view of a substantial portion of a deflection yoke shown in FIGS. 2 and 3.  
         [0024]    [0024]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.  
         [0025]    [0025]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.  
         [0026]    [0026]FIG. 7 is for explaining an operation of a magnetic ring for a deflection yoke shown in FIG. 6 according to the present invention.  
         [0027]    [0027]FIG. 8 is an enlarged view of a substantial portion of a second embodiment of a deflection yoke according to the present invention.  
         [0028]    [0028]FIG. 9 is an enlarged view of a substantial portion of a third embodiment of a deflection yoke according to the present invention.  
         [0029]    [0029]FIG. 10 is an enlarged view of a substantial portion of a fourth embodiment of a deflection yoke according to the present invention.  
         [0030]    [0030]FIG. 11 is a perspective view for explaining an example of a deflection yoke for a cathode ray tube according to the prior art.  
         [0031]    [0031]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  
       [0032]    [0032]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.  
         [0033]    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.  
         [0034]    [0034]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.  
         [0035]    [0035]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.    
         [0036]    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.  
         [0037]    [0037]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 .  
         [0038]    [0038]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 .  
         [0039]    [0039]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.  
         [0040]    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.  
         [0041]    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 if 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.  
         [0042]    [0042]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 .  
         [0043]    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  
       [0044]    [0044]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 .  
         [0045]    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  
       [0046]    [0046]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.    
         [0047]    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.  
         [0048]    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  
       [0049]    [0049]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 .  
         [0050]    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 bold position of the inner circumference surface of the magnetic rings  10  and  11 .  
         [0051]    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.  
         [0052]    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 if 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.  
         [0053]    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.  
         [0054]    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.