Abstract:
The invention provides a deflection yoke comprising: a funnel-shaped core (ii) being made of a magnetic material, (iii) having, on its inner wall, ridges each of which starts from the narrower end and extends toward the wider end for a part of the length of the core, the ridges being arranged circumferentially at intervals and thereby forming core slots, and (iv) in which the remaining inner wall near the wider end is smooth; a first deflection coil wound as partially guided by the core slots; second deflection coil positioned more inward than the first deflection coil; and an insulating frame that (i) is sandwiched between the first and second deflection coils, and (ii) has, in an area corresponding to the core&#39;s smooth area, guiding slots extending along the CRT axis direction and being arranged circumferentially, wherein the second deflection coil is wound as partially guided by the guiding slots.

Description:
This application is based on the applications Nos. 2002-167269, 2002-173755 filed in Japan, the contents of which are hereby incorporated by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to CRT (Cathode Ray Tube) devices used for TVs and computer displays, and deflection yokes used in such CRT devices, particularly to the structures of the deflection yokes. 
   2. Description of the Related Art 
   There is a type of deflection yoke that comprises what is called a slot core. A slot core denotes a type of a funnel-shaped ferrite core that has, on the inner wall thereof, a plurality of slots each of which extends from the narrower end to the wider end, the plurality of slots being arranged circumferentially. A vertical deflection coil and a horizontal deflection coil are wound so as to be guided by the slots of the ferrite core. 
   A deflection yoke with such an arrangement has the following advantageous effects over a deflection yoke including a ferrite core that is simply funnel-shaped and has a smooth inner wall: The deflection sensitivity is improved because it is possible to position the ferrite core closer to the cathode ray tube. Also, it is possible to reduce eddy-current loss and inhibit heat generation of the deflection yoke because the magnetic flux is less likely to have a flux linkage with the deflection coils. 
   One of the problematic issues concerning a deflection yoke to which a slot core is applied is how to provide insulation between the vertical deflection coil and the horizontal deflection coil while maintaining the productivity in the manufacturing of deflection yokes. To be more specific, in a case of a ferrite core that is simply funnel-shaped, the vertical deflection coil and the horizontal deflection coil disposed inside can be insulated by inserting, between those coils, an insulating frame that is simply funnel-shaped likewise. On the other hand, in a case of a slot core, since the vertical deflection coil and the horizontal deflection coil are wound so as to be disposed in each of the slots, insulation cannot be provided so simply as that. 
   One of the examples that have solved the aforementioned problem is a deflection yoke disclosed in the Japanese Unexamined Patent Application Publication No. 11-7891. In this deflection yoke, a funnel-shaped insulating frame as a whole is formed with ridges and slots to fit the ridges and slots in the slot core. Then, after winding a vertical deflection coil directly into the slots of the slot core, the aforementioned insulating frame gets fitted into the slots of the slot core. Subsequently, a horizontal deflection coil gets wound into the slots on the inner wall of the insulating frame. According to this arrangement, there is no loss in the productivity because the insulation between the deflection coils is made by a very simple operation of fitting, onto a slot core, an insulating frame that is shaped to fit the slots of the slot core, after a vertical deflection coil is wound. 
   Another problematic issue concerning a deflection yoke to which a slot core is applied is how to obtain a deflection magnetic field distribution as desired. This issue arises from circumstances as follows: In a case of a slot core, since the deflection coils are wound along the slots as mentioned above, the winding pattern of a deflection coil which determines the deflection magnetic field distribution is restricted by the ridges and slots (the slot pattern) of the slot core. This is because a slot core (a ferrite core) has a little flexibility in formation of a slot pattern due to its manufacturing process. The deflection yoke disclosed in the aforementioned Japanese Unexamined Patent Application Publication No. 11-7891 has a little flexibility because the winding pattern of not only the vertical deflection coil that is wound directly on the slot core, but also of the horizontal deflection coil, as a result, is restricted by the slot pattern of the slot cores. 
   In order to cope with this second problematic issue, a deflection yoke is disclosed in the Japanese Examined Utility Model Application Publication No. 7-35289, for example. A funnel-shaped ferrite core used in this deflection yoke has slots formed only in the area of the narrower half, and the inner wall of the wider half is smooth without ridges or slots, so that the flexibility of winding pattern can be achieved in the wider half; however, the Japanese Examined Utility Model Application Publication No. 7-35289 fails to disclose an insulating means between the deflection coils, let alone specific guiding means for the deflection coils. 
   SUMMARY OF THE INVENTION 
   A first object of the present invention is to provide a deflection yoke in which the insulation between the horizontal deflection coil and the vertical deflection coil is ensured and that has more flexibility in the winding pattern. 
   A second object of the present invention is to provide a CRT device comprising such a deflection yoke. 
   It is possible to achieve the first object of the present invention with a deflection yoke provided on an external surface of a cathode ray tube, comprising: a tube-shaped core (i) in which an opening at a first end is smaller than an opening at a second end, (ii) that is made of a magnetic material, (iii) that has, on an inner wall thereof, a plurality of ridges each of which starts from the first end and extends toward the second end for a part of a length of the core, the plurality of ridges being arranged circumferentially at predetermined intervals and thereby forming a plurality of core slots, and (iv) in which a remaining area of the inner wall thereof in a vicinity of the second end is finished to be smooth; a first deflection coil that is wound on the core so as to be partially guided by one or more of the core slots; a second deflection coil that is positioned more inward than the first deflection coil; and an insulating frame that (i) is sandwiched between the first deflection coil and the second deflection coil, and (ii) has, in an area thereof that corresponds to the smoothly-finished remaining area of the core and/or in an area thereof that extends off the second end of the core in a tube axis direction, a plurality of guiding slots extending along the tube axis direction of the cathode ray tube and being arranged circumferentially, wherein the second deflection coil is wound so as to be partially guided by one or more of the guiding slots. 
   It is possible to achieve the second object of the present invention with a cathode ray tube device including a cathode ray tube and a deflection yoke provided on an external surface of the cathode ray tube, the deflection yoke comprising: a tube-shaped core (i) in which an opening at a first end is smaller than an opening at a second end, (ii) that is made of a magnetic material, (iii) that has, on an inner wall thereof, a plurality of ridges each of which starts from the first end and extends toward the second end for a part of a length of the core, the plurality of ridges being arranged circumferentially at predetermined intervals and thereby forming a plurality of core slots, and (iv) in which a remaining area of the inner wall thereof in a vicinity of the second end is finished to be smooth; a first deflection coil that is wound on the core so as to be partially guided by one or more of the core slots; a second deflection coil that is positioned more inward than the first deflection coil; and an insulating frame that (i) is sandwiched between the first deflection coil and the second deflection coil, and (ii) has, in an area thereof that corresponds to the smoothly-finished remaining area of the core and/or in an area thereof that extends off the second end of the core in a tube axis direction, a plurality of guiding slots being arranged circumferentially at intervals that are different from the intervals at which the core slots are arranged, wherein the second deflection coil is wound so as to be partially guided by one or more of the guiding slots. 
   It is also possible to achieve the second object of the present invention with a cathode ray tube device including a cathode ray tube and a deflection yoke provided on an external surface of the cathode ray tube, the deflection yoke comprising: a tube-shaped core (i) in which an opening at a first end is smaller than an opening at a second end, (ii) that is made of a magnetic material, (iii) that has, on an inner wall thereof, a plurality of ridges each of which starts from the first end and extends toward the second end for a part of a length of the core, the plurality of ridges being arranged circumferentially at predetermined intervals and thereby forming a plurality of core slots, and (iv) in which a remaining area of the inner wall thereof in a vicinity of the second end is finished to be smooth; a first deflection coil that is wound on the core so as to be partially guided by one or more of the core slots; a second deflection coil that is positioned more inward than the first deflection coil, and is wound so that part of its length is disposed in one or more of the core slots; and an insulating frame that (i) is sandwiched between the first deflection coil and the second deflection coil, and (ii) has, in an area thereof that corresponds to the smoothly-finished remaining area of the core and/or in an area thereof that extends off the second end of the core in a tube axis direction, a plurality of guiding slots extending along a central axis direction of the core and being arranged circumferentially, wherein the guiding slots are provided being a predetermined distance apart, in the central axis direction, from the core slots, and the second deflection coil is wound so as to be partially guided by one or more of the guiding slots. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate a specific embodiment of the invention. 
     In the drawings: 
       FIG. 1  is a side view to illustrate the general structure of the CRT device; 
       FIG. 2  is a front view to illustrate the general structure of the deflection yoke; 
       FIG. 3  is the A—A cross section of  FIG. 2 ; 
       FIG. 4  is the B—B cross section of  FIG. 2 ; 
       FIG. 5  is a front view of the ferrite core on which a vertical deflection coil is wound; 
       FIG. 6  is a front view of the insulating frame; 
       FIG. 7  is a side view of a part of the insulating frame; 
       FIG. 8  is a cross section of the deflection yoke, being sectioned at a plane perpendicular to the tube axis of the cathode ray tube; 
       FIG. 9  is a side view of the insulating frame in the deflection yoke of the second embodiment; 
       FIG. 10  shows an end of the insulating frame of the second embodiment on the electron gun side, being viewed from the electron gun side; 
       FIG. 11  is a cross section of the deflection yoke of the second embodiment, being sectioned at a plane perpendicular to the tube axis of the cathode ray tube; 
       FIG. 12  is a side view of a part of the insulating frame in the deflection yoke of the third embodiment; and 
       FIG. 13  is a cross section of the deflection yoke of the third embodiment, being sectioned at a plane perpendicular to the tube axis of the cathode ray tube. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following describes embodiments of the present invention, with reference to the drawings. 
   First Embodiment 
     FIG. 1  is a schematic side view of a color CRT device  10  of an embodiment. The color CRT device  10  comprises: an evacuated envelope  16  in which (a) a front flat panel  12  whose inner surface has a phosphor screen formed thereon and (b) a funnel  14  are joined together; an electron gun  18  disposed in the neck of the funnel  14 ; a deflection yoke  20  disposed on the external surface of the funnel  14 ; and a convergence yoke  22 .  FIG. 1  merely shows the positional relationship among the aforementioned members, and the members such as the deflection yoke  20  are illustrated in very simplified forms. 
     FIG. 2  is a front view of the deflection yoke  20  being viewed from the phosphor screen side. In the present application, X denotes a horizontal axis, and Y denotes a vertical axis. Further, an axis that perpendicularly intersects both the X axis and the Y axis at the origin (the zero point) at which the X axis intersects the Y axis will be referred to as the Z axis (the tube axis). 
   Additionally,  FIG. 3  is the A—A cross section of FIG.  2 .  FIG. 4  is the B—B cross section of FIG.  2 . 
   As shown in  FIGS. 2 ,  3 , and  4 , the deflection yoke  20  is made of a magnetic material and includes a core  24  which as a whole is substantially tube-shaped. Inside the core  24 , a vertical deflection coil  26 , an insulating frame  28 , and a horizontal deflection coil  30  are disposed in the stated order. Ferrite is used as a magnetic material in the present embodiment. Hereafter, the core  24  will be referred to as a ferrite core  24 . 
   As shown in  FIG. 1 , the ferrite core  24  is funnel-shaped, more specifically, the diameter at the end on the phosphor screen (the front flat panel  12 ) side is larger than the diameter at the other end on the electron gun  18  side. In other words, the ferrite core  24  is substantially tube-shaped and whose diameter gets larger beginning from the electron gun  18  side thereof (the narrower end) toward the phosphor screen side thereof (the wider end). 
     FIG. 5  is a front view of the ferrite core  24  on which the vertical deflection coil  26  is wound. 
   Formed on the inner wall of the ferrite core  24  are a plurality of ridges “Rs” (hereafter referred to as core ridges) each of which extends along the Z axis (the tube axis) direction so as to protrude toward the Z axis, the plurality of core ridges being arranged circumferentially at regular intervals. In the present example, twenty core ridges are formed at 18-degree intervals. As shown in  FIGS. 4 and 5 , each of the core ridges Rs extends substantially halfway from the narrower end (the end on the electron gun side) to the larger end (the end on the phosphor screen side). As shown in  FIG. 5 , viewing the ferrite core  24  from the front (from the phosphor screen side) helps you understand that the core ridges Rs are provided in a radial pattern. As for the core ridges Rs on the X axis, the core ridge that is on the right side as we face  FIG. 5  will be referred to as R 1 , and serial numbers will be given counterclockwise starting from R 1 , in order to identify each of the core ridges as R 1  to R 20 . 
   As a result of the core ridges Rs being formed, a slot (hereafter referred to as a core slot) “S” is formed between the ridges positioned adjacent to each other. The core slot formed by the core ridge R 1  and the core ridge R 2  will be referred to as the core slot S 1 , and serial numbers will be given counterclockwise starting from S 1 , in order to identify each of the core slots as S 1  to S 20 . 
   The remainder of the inner wall of the ferrite core  24  in the Z axis (tube axis) direction where no core ridges Rs are formed (i.e. where no core slots Ss are formed) is finished to be smooth. 
   Hereafter, of the inner wall of the ferrite core  24 , the area in which core slots Ss are formed will be referred to as a core slot area, and the area that is finished to be smooth will be referred to as a smooth area. 
   Further, projections “Ps” are provided on the external surface of the ferrite core  24  at the vicinity of the wider end at such positions to which the lines extended from the core ridges R 1  to R 20  correspond respectively. The projections Ps are pins made of synthetic resin that are adhered to the external surface of the ferrite core  24 . Here again, the projections Ps are identified by serial numbers like the core ridges Rs. 
   A vertical deflection coil  26  is wound into the shape of a saddle directly on the ferrite core  24  that has the aforementioned arrangements. 
   In the core slot area, the vertical deflection coil  26  is wound so as to be disposed in the core slots S 2  to S 9 , and S 12  to S 19 , and not in the core slots S 1 , S 10 , S 11 , and S 20 . Thus, in the core slot area, the vertical deflection coil  26  is wound with a winding angle defined by the core slots S 2  to S 9 , and S 12  to S 19 . 
   On the external surface of the ferrite core  24  at the vicinity of the wider end, the vertical deflection coil  26  is wound so as to hook around the projections Ps. In other words, as the vertical deflection coil  26  is wound with a winding angle defined by the projection Ps, the winding distribution as desired can be achieved in the smooth area. The positions of the projections Ps are not limited to the ones mentioned above, and it is also acceptable to dispose the projections Ps at arbitrary positions, being irrelevant to the positions of the core ridges. According to this arrangement, it is possible to achieve, in the smooth area, winding distribution that is not restricted so much by the positions of the core slots. 
     FIG. 6  is a partially cut-out front view of the insulating frame  28 .  FIG. 7  is a plan view of the insulating frame  28 . 
   The insulating frame  28  includes a main body  29  that is substantially in the shape of a truncated cone so as to fit the external shape of the funnel  14 , and is made of synthetic resin. The insulating frame  28  electrically insulates the vertical deflection coil  26  from the horizontal deflection coil  30 . 
   The main body  29  is made up of an insulating frame cone  32  that widens toward the phosphor screen side and an insulating frame neck  34  that extends toward the electron gun side. 
   Formed on the inner wall of the insulating frame cone  32  are a plurality of projections “Qs” (hereafter referred to as guiding projections) each of which extends along the Z axis (the tube axis) direction so as to protrude toward the Z axis, the plurality of guiding projections being arranged circumferentially at predetermined intervals. The guiding projections Qs are curved bars made of synthetic resin that are adhered to the inner wall of the main body  29 . As shown in  FIGS. 6 and 7 , the guiding projections Qs are provided on the wider end side (the end on the phosphor screen side) of the main body  29 . As shown in  FIG. 6 , viewing the insulating frame  28  from the front (from the phosphor screen side) helps you understand that the guiding projections Qs are provided in a radial pattern. As for the guiding projections Qs on the X axis, the guiding projection that is on the right side as we face  FIG. 6  will be referred to as Q 1 , and serial numbers will be given counterclockwise starting from Q 1 , in order to identify each of the guiding projections as Q 1  to Q 26 . The end of each of the guiding projections Q 1  to Q 26  on the phosphor screen side is apart from the inner wall of the main body  29  (the insulating frame cone  32 ) so as to form a space therebetween. As will be explained later, the horizontal deflection coil  30  is wound so as to hook around each of the parts of the guiding projections Qs that form such spaces. 
   As a result of the guiding projections Qs being formed as mentioned above, a slot (hereafter referred to as a guiding slot) “G” is formed between the guiding projections Qs adjacent to each other. The guiding slots are formed in an area of the insulating frame  28  that corresponds to the smooth area of the ferrite core  24  and/or in an area that is relatively more on the phosphor screen side. The guiding slot formed by the guiding projection Q 1  and the guiding projection Q 2  will be referred to as the guiding slot G 1 , and serial numbers will be given counterclockwise starting from G 1 , in order to identify each of the guiding slots as G 1  to G 26 . 
   Provided in the insulating frame neck  34  are a plurality of slits each of which extends along the Z axis (the tube axis) direction, and has a predetermined width and a predetermined length. The width will be determined according to the width of the core ridges Rs in the ferrite core  24 . The length will be determined according to the length of the core ridges Rs in the ferrite core  24 . 
   As a result of such slits being provided, the insulating frame cone  32  has a plurality of belt-shaped members protruding. As shown in  FIG. 7 , with such belt-shaped members protruding, the insulating frame neck  34  looks like it has teeth of a comb. Here, the slits are identified with the letters Ls, and the belt-shaped members are identified with the letters Ts. In addition, as shown in  FIG. 6 , serial numbers are given in the same manner as mentioned earlier, in order to identify each of the slits and the belt-shaped members. 
   The insulating frame  28  with the aforementioned arrangements will be attached to the ferrite core  24  ( FIG. 5 ) on which the vertical deflection coil  26  is wound. The procedure of attaching the insulating frame  28  to the ferrite core  24  is done by inserting the insulating frame  28 , with its end on the insulating frame neck  34  side first, into the wider end of the ferrite core  24 . At this time, the insulating frame  28  and the ferrite core  24  will be attached to each other by relatively being slid in the Z axis (the tube axis) direction, so that the slits L 1  to L 20  are fitted into the corresponding core ridges R 1  to R 20  respectively, in other words, so that the belt-shaped members T 1  to T 20  go into the corresponding core slots S 1  to S 20  respectively. 
   After the insulating frame  28  and the ferrite core  24  are attached together, the free ends (the ends on the electron gun side) of the belt-shaped members T 1  to T 20  of the insulating frame  28  will be linked together. Also, a donut-shaped ring  36  made of synthetic resin will be attached in the vicinity of the linking position in order to provide insulation between the vertical deflection coil  26  and the horizontal deflection coil  30 . The linking is done by arching from one free end to another. In addition to the aforementioned effect, the ring  36  also serves to ensure mechanical strength of the ends of the belt-shaped members T 1  to T 20 , as well as to provide dimensional stability. It is acceptable to join the ring with the belt-shaped members T 1  to T 20  by adhesion; alternatively it is also acceptable to provide male couplings on one of the ring and the belt-shaped members and female couplings on the other of those two, so that the male couplings and the female couplings can be fitted into each other. 
   After the ring  36  is attached, the horizontal deflection coil  30  will be wound into the shape of a saddle on the insulating frame  28  as shown in FIG.  2 . 
   It is acceptable to provide the guiding projections Qs only in the area where the horizontal deflection coil  30  is wound.  FIGS. 2 and 6  illustrate an example in which the projections Qs are not provided in the vicinity of the Y axis. It is also acceptable to provide guiding slots in the main body  29  of the insulating frame  28 , instead of guiding projections Qs. 
     FIG. 8  shows a cross section of the deflection yoke  20  after the horizontal deflection coil  30  is wound thereon, the deflection yoke being sectioned at a plane perpendicular to the Z axis (the tube axis). The sectioning point of the cross section is positioned, in terms of the Z axis direction, at where the ferrite core  24  has the core slots. In  FIG. 8 , the sectional view of each of the deflection coils is simply indicated with hatching. As shown in  FIG. 8 , in the core slot area, the vertical deflection coil  26  and the horizontal deflection coil  30  are wound so as to be guided by the core slots S 1  to S 20 . These two kinds of coils are securely insulated from each other by the belt-shaped members Ts. 
   In the smooth area of the ferrite core  24 , the vertical deflection coil  26  is wound so as to hook around the projections Ps that may be provided irrelevant to the positions of the core slots, as mentioned earlier. Thus, it is possible to achieve flexible winding distribution which is not so much restricted by the pattern of the core slots. Also, in the smooth area of the ferrite core  24 , the horizontal deflection coil  30  is wound so as to be guided by the guiding slots Gs that may be provided irrelevant to the positions of the core slots. Thus, it is possible to achieve flexible winding distribution which is not so much restricted by the pattern of the core slots. 
   In the present embodiment, the guiding slots Gs are arranged at intervals that are different from the intervals at which the core slots Ss are arranged. This way, it is possible to achieve, in the smooth area, flexible winding distribution that is not so much restricted by the core slots Ss. 
   Additionally, in the present embodiment, the guiding slots Gs are provided being a predetermined distance apart, in the Z axis direction, from the core slots Ss. Hereafter, the area provided because they are apart from each other, which is indicated with the number  38  in  FIG. 2 , will be referred to as the “partitioning area”. Since  FIG. 2  is already crowded, indicating the partitioning area with lines in  FIG. 2  will make it more complicated; therefore, the equivalent of the partitioning area  38  is indicated in  FIG. 6 , which is an area between the two circles, a large one and a small one, drawn with dotted lines. With such an arrangement, even if the core slots Ss and the guiding slots Gs are arranged circumferentially at the same intervals, it is still possible to alter the winding direction of the horizontal deflection coil  30  when it comes to the partitioning area  38 . For example, it is possible to wind the horizontal deflection coil from a core slot S, not to a guiding slot G positioned on the line extended from the core slot S, but rather to another guiding slot positioned next to that guiding slot. Accordingly, it is possible to achieve, in the smooth area, winding distribution that is not restricted by the pattern of the core slots. 
   Second Embodiment 
   The second embodiment basically has the same arrangements as the first embodiment except for the structure of the insulating frame. Consequently, explanation on the arrangements in common will be omitted, and the explanation will focus on the insulating frame. 
     FIG. 9  is a side view of the insulating frame  40  of the second embodiment.  FIG. 10  shows an end of the insulating frame  40  on the electron gun side, being viewed from the electron gun side.  FIG. 11  is a cross section of the deflection yoke of the second embodiment, being sectioned at a plane perpendicular to the tube axis of the Z axis (the tube axis). The sectioning point of the cross section is positioned, in terms of the Z axis direction, at where the ferrite core  24  has the core slots. In  FIG. 9 , the guiding projections Qs are omitted from the drawing. 
   The insulating frame  40  is different from the insulating frame  28  in the shape of the cross section of the insulating frame neck. More specifically, it is different in the shape of the cross section of the parts where the vertical deflection coil is insulated from the horizontal deflection coil inside each of the slots (hereafter the parts will be referred to as the “insulating parts inside the core slots”). 
   As shown in  FIG. 11 , each of the insulating parts inside the core slots  42  has a pair of ribs  44  on the sides and is in the shape of a U. Thus, the insulating parts inside the core slots  42  serve to enhance the mechanical strength as well as to increase the insulation level between the vertical deflection coil  26  and the horizontal deflection coil  30 . 
   The ring  46  is provided in the same manner as in the first embodiment. 
   Third Embodiment 
   The third embodiment basically has the same arrangements as the first embodiment except that the structure of the insulating frame is different from the ones in the first and second embodiments. Consequently, explanation on the arrangements in common will be omitted, and the explanation will focus on the insulating frame. 
     FIG. 12  is a side view of the insulating frame  50  of the third embodiment.  FIG. 13  is a cross section of the deflection yoke of the third embodiment, being sectioned at a plane perpendicular to the Z axis (the tube axis). The sectioning point of the cross section is positioned, in terms of the Z axis direction, at where the ferrite core  24  has the core slots. In  FIG. 12 , the guiding projections Qs and the ring are omitted from the drawing. 
   The insulating frame  50  is different from the insulating frames  28  and  40  in the shape of the cross section of the insulating frame neck. As shown in  FIG. 13 , slits are not provided in the insulating frame  50 , unlike in the insulating frames  28  and  40 ; the insulating frame  50  therefore is a continuum circumferentially. The insulating frame neck  52  of the insulating frame  50  extends from the insulating frame cone  54 , and is formed into a tube with corrugation that fits into the ridges and slots in the core slot area. 
   The following provides detailed explanation: 
   The insulating frame  50  has slots  56  (protruding inwardly) and insulating parts  58  (protruding outwardly) that are arranged so as to alternate circumferentially. The slots  56  of the insulating frame  50  fit to the core ridges Rs of the ferrite core  24 , respectively. The insulating parts  58  of the insulating frame  50  fit to the core slots Ss, respectively. There is a space for winding the vertical deflection coil  26  provided between each of the core slots Ss of the ferrite core  24  and each of the insulating parts  58  of the insulating frame  50 . There is a space for winding the horizontal deflection coil  30  provided on the internal wall side of each of the insulating parts  58  of the insulating frame  50 . 
   With such arrangements, it is possible to further enhance the mechanical strength of the insulating frame neck as well as to further ensure the insulation between the deflection coils. 
   The procedure for assembling the deflection yoke is the same as in the first embodiment; it will be therefore partially redundant, but the explanation on the procedure is provided below. 
   First, the vertical deflection coil  26  is wound so as to be in the core slots Ss of the ferrite core  24 . Next, the insulating frame  50  will be inserted into the end of the ferrite core  24  on the phosphor screen side (the wider end). As shown in  FIG. 13 , the opening width of each of the core slots Ss (in the circumferential direction) is smaller than the width of each of the tips of the insulating parts  58  of the insulating frame  50 . Accordingly, the core slots Ss are positioned to fit the positions of the insulating parts  58 , and the core slots Ss and the insulating parts  58  are slid against each other to the Z axis direction, so that the insulating parts  58  of the insulating frame  50  are inserted into each of the corresponding core slots Ss, respectively. After the ferrite core  24  and the insulating frame  50  are joined together this way, a ring (not shown in the drawing) will be attached, and the horizontal deflection coil  30  will be wound along the inner wall of the slots of the insulating parts  58 . 
   Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.