Abstract:
A deflection yoke including a separator for holding a horizontal deflection coil and/or a vertical deflection coil, wherein the separator is formed by a combination of a separator main body formed into an approximately funnel shape similar to the contour of the horizontal deflection coil or the vertical deflection coil, and an approximately cylindrically shaped neck portion, formed separately from the separator main body, for holding the horizontal deflection coil and the vertical deflection coil on a neck of a cathode-ray tube. The deflection yoke is simpler in shape and easier to assemble.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a deflection yoke used for a CRT, for example, of a type in which a horizontal deflection coil formed by die winding is arranged. In particular, the present invention relates to a deflection yoke having a separator which is formed by combining a separator main body formed in an approximately funnel shape similar to the contour of a deflection coil with a neck portion for holding the deflection coil on the neck of a cathode-ray tube, to thereby simplify the shape of the separator and also simplify its assembling works. 
     In a related art deflection yoke described in Page 259 of the Proceedings of the 5th Sony Research Forum &#39;95, as shown in FIG. 1, a deflection coil is held on the neck of a cathode-ray tube via a separator, and various correction coils for correcting deflection magnetic fields and the like are arranged on the separator. 
     A separator is, for example, injection-molded from a resin into a shape similar to the contour of the cathode-ray tube between a funnel portion and a neck portion, that is, an approximately funnel shape, and a cylindrical shape connected to the approximately funnel shape on its small diameter side. 
     In a deflection yoke, a horizontal deflection coil wound in, for example, a saddle shape by using a die is arranged inside an approximately funnel portion of a separator, and a vertical deflection coil wound around a core is arranged outside the approximately funnel portion of the separator. Further, in the deflection yoke, a flange is formed at a connection portion between the approximately funnel portion and a cylindrical portion, and correction mechanisms for correcting a convergence characteristic and a terminal board for connecting the correction mechanisms to the deflection coil are arranged on the flange and further on the cylindrical portion. In the deflection yoke, a band is arranged at an end portion of the cylindrical portion. The neck of a cathode-ray tube is inserted into the cylindrical portion, and then the band is fastened to certainly hold the cylindrical portion with the neck of the cathode-ray tube. 
     In recent years, there has been a tendency to arrange various convergence correction mechanisms on a deflection yoke for improving the convergence characteristic. 
     The arrangement of the various convergence correction mechanisms on a deflection yoke causes problems that the shape of a separator is correspondingly complicated, and that it takes a lot of time to mount these convergence correction mechanisms and correspondingly it take a lot of time to assemble the deflection yoke. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a deflection yoke capable of simplifying the shape thereof and also simplifying the assembling works therefor. 
     To achieve the above object, according to the present invention, there is provided a deflection yoke including: a separator for holding a horizontal deflection coil and/or a vertical deflection coil, wherein the separator is formed by a combination of: a separator main body formed into an approximately funnel shape similar to the contour of the horizontal deflection coil or the vertical deflection coil; and an approximately cylindrical shaped neck portion, formed separately from the separator main body, for holding the horizontal deflection coil and the vertical deflection coil on a neck of a cathode-ray tube. 
     Since the separator is formed by a combination of the separator main body and the neck portion, the separator main body and the neck portion can be separately pre-assembled, accordingly making simple the works of mounting convergence correcting mechanisms and the like. Further, since the separator main body and the neck portion can be separately formed, it is possible to lessen various restricting conditions in design such as the releasing direction of a die or the like, and hence to accordingly simplify the shape of the separator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view showing a prior art deflection yoke; 
     FIG. 2 is an exploded perspective view showing a separator used for a deflection yoke according to an embodiment of the present invention; 
     FIG. 3 is an exploded perspective view showing a configuration of a neck portion shown in FIG. 2; 
     FIG. 4 is a plan view of a separator shown in FIG. 2; and 
     FIG. 5 is a sectional view taken on line H—H of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 2 is an exploded perspective view showing a separator used for a deflection yoke according to an embodiment of the present invention. The deflection yoke in this embodiment is of a type in which a pair of horizontal deflection coils wound in a saddle-shape are arranged inside a separator  1  and a vertical deflection coil wound around a core is arranged outside the separator  1 . 
     The separator  1  is prepared by a combination of a separator main body  2  and a neck portion  3 . The separator main body  2  is prepared by a combination of a pair of separator main body portions  4  and  5 . 
     The separator main body portions  4  and  5  are injection-molded from a resin into shapes identical with each other, more specifically, equivalent to halves of an approximately funnel shape similar to the contour of both a neck portion and a funnel portion of a cathode-ray tube, divided along a virtual plane containing the tube axis of the cathode ray-tube. The separator main body portions  4  and  5  have circular-arc flanges  4 A and  5 A at end surfaces on the display screen side and rectangular flanges  4 B,  4 C and  5 B,  5 C on the neck side, respectively. 
     With respect to these separator main body portions  4  and  5 , claws  6 A and engagement portions  6 B into which the claws  6 A are to be engaged are oppositely formed on the flanges  4 A and  5 A on the display screen side and on the outer flanges  4 B and  5 B on the neck side. By pressingly inserting the claws  6 A into openings of the associated engagement portions  6 B as shown by an arrow A in FIG. 2, the separator main body portions  4  and  5  are integrated with each other to form the separator main body  2 . 
     The inner sides of the neck side flanges  4 B,  4 C and  5 B,  5 C of the separator main body portions  4  and  5  are each curved in a circular-arc shape similar to the contour of the cathode-ray tube. The separator main body portions  4  and  5  hold the neck portion  3  by clamping it with the circular-arc shaped inner end surfaces of the flanges  4 B,  4 C, and  5 B,  5 C. 
     In regard to the outer flanges  4 B and  5 B of the separator main body portions  4  and  5 , approximately central portions of the circular-arc inner end surfaces project inwardly, to form projections  4 D and  5 D, respectively. The inner end surfaces of the projections  4 D and  5 D are each formed into a circular-arc shape. The projections  4 D and  5 D are inserted in openings  9 B (which will be described later) of the neck portion  3  as shown by an arrow B in FIG. 2 for preventing the displacement of the neck portion  3 . 
     The neck side surfaces of the flanges  4 B and  5 B of the separator main body portions  4  and  5  are partially raised and folded to form approximately U-shaped walls  4 E and  5 E opened toward the center side, respectively. As shown by an arrow C, coils  8  formed on the neck portion  3  are to be inserted in spaces formed in the U-shaped walls  4 E and  5 E for preventing the turning of the neck portion  3 . 
     As shown in FIG. 3, the neck portion  3  is composed of a bobbin  9  and a correction coil holding portion  10 . 
     The correction coil holding portion  10 , which is injection-molded from a resin, has an approximately cylindrical main body  10 A and a rectangular flange  10 B arranged on the funnel side. The correction coil holding portion  10  also has a pair of coil bobbins  10 C formed in the direction perpendicular to the extending direction of the flange  10 B. The main body  10 A is formed so as to cover the side surface of the bobbin  9  for preventing coils  15 A,  15 B,  15 C, . . . (which will be described later) wound on the bobbin  9  from being exposed. 
     Each of the pair of coil bobbins  10 C of the correction coil holding portion  10  has a flange for allowing a magnet wire  11  to be wound around the coil bobbin  10 C. The coil bobbin  10 C also has at its center an opening for holding a core. In a pre-assembly of the correction coil holding portion  10  before being assembled with the bobbin  9 , the magnet wires  11  are wound around the pair of coil bobbins  10 C to form coils  8  for generating a magnetic field crossing the tube axis of the cathode-ray tube, and the cores  12  are arranged in the openings at the centers of the coil bobbins  10 C. The coils  8  are thus allowed to generate the magnetic field for correction of the convergence characteristic, crossing the tube axis of the cathode-ray tube, with a good efficiency. 
     As shown in FIG. 4, when the correction coil holding portion  10  is assembled with the separator main body  2 , the flanges of the pair of coil bobbins  10 C are clamped in the walls  4 E and  5 E of the separator main body portions  4  and  5  for preventing the displacement of the correction coil holding portion  10  turned around the tube axis as shown by an arrow D. 
     The flange  10 B of the correction coil holding portion  10  holds other convergence correction coils  13  (see FIG.  3 ). At this time, the correction coils  13  are held on the surface, on the separator main body  2  side, of the flange  10 B of the correction coil holding portion  10 , in order that when the neck portion  3  is assembled with the separator main body  2  into a deflection yoke, the correction coils  13  are covered with the flange  10 B for preventing the correction coils  13  from being easily touched by an operator. 
     One end surface of the flange  10 B of the correction coil holding portion  10  projects and a rectangular terminal board holding portion  10 E is formed at the projecting end of the end surface of the flange  10 B. A terminal board  14  is held on the terminal board holding portion  10 E. 
     In the pre-assembly of the correction coil holding portion  10  before being assembled with the bobbin  9 , as described above, the magnet wires  11  and the cores  12  are arranged on the coil bobbins  10 C to form the coils  8  for correction of the convergence characteristic, then the correction coils  13  are arranged on the flange  10 B and the terminal board  14  is arranged on the terminal board holding portion  10 E, and the coils  8  and the correction coils  13  are wired to the terminal board  14 . 
     The bobbin  9  has flanges extending in parallel to its center axis, which flanges are arranged on the outer peripheral surface of the bobbin  9  at intervals of a specific angle. Magnet wires are wound on the bobbin  9  using the flanges, whereby a plurality of coils  15 A,  15 B,  15 C, . . . are formed on the bobbin  9 . Here, the plurality of coils  15 A,  15 B,  15 C, . . . are formed by sequentially winding the magnet wires on the bobbin  9  at intervals of about 45°. The magnetic fields generated by the coils  15 A,  15 B,  15 C, . . . allows the bobbin  9  to form a magnetic field for correction of the convergence characteristic. 
     The outer periphery, on the separator main body  2  side, of the bobbin  9  is stepwise depressed to form a groove  9 A, and rectangular openings  9 B are formed in the groove  9 A. When the bobbin  9  is assembled with the separator main body  2 , as shown by a partial cross-section on a large scale (indicated by an arrow F in FIG.  4 ), the projections  4 D and  5 D of the separator main body portions  4  and  5  are inserted in the openings  9 B of the bobbin  9  for preventing the turning of the bobbin  9  around the tube axis as shown by an arrow G. As shown in FIG. 5 which is a sectional view taken on line H—H of FIG. 4, by meshing the flanges  4 B and  5 B of the separator main body portions  4  and  5  with the groove  9 A and also inserting the projections  4 D and  5 D of the separator main body portions  4  and  5  in the openings  9 B, the displacement of the bobbin  9  in the direction along the tube axis of the cathode-ray tube, indicated by an arrow I, is prevented. 
     A projection  9 C is formed on the outer side surface, opposite to the groove  9 A, of the bobbin  9  (see FIG.  3 ), and a band  18  for fixing the deflection yoke on the neck of the cathode-ray tube is attached around the bobbin  9  via the projection  9 C (see FIG.  5 ). After the bobbin  9  (see FIG. 3) is integrated with the separator main body portions  4  and  5 , the correction coil holding portion  10  and the band  18  are pressedly inserted around the bobbin  9  in sequence. At this time, the displacement of the band  18  in the direction of the tube axis is prevented by the projection  9 C, so that the displacement of the correction coil holding portion  10  in the direction along the tube axis as shown by an arrow J is prevented by the band  18  and the flanges  4 B and  5 B of the separator main body portions  4  and  5 . 
     In the deflection yoke according to this embodiment, the bobbin  9  and the correction coil holding portion  10  pre-assembled in the separate steps are integrated with the separator main body portions  4  and  5  and the horizontal defection coil, and then the vertical defection coil is mounted to the unit thus integrated. 
     The assembly of the deflection yoke having the above configuration will be described below. First, at the pre-assembly step of the bobbin  9  (see FIG.  3 ), the magnet wires are wound around the bobbin  9  to form the coils  15 A,  15 B,  15 C, . . . for correction of the convergence characteristic. 
     At the pre-assembly step of the correction coil holding portion  10 , the magnet wires are wound around the coil bobbins  10 C to arrange the coils  8  for correction of the convergence characteristic, and the cores  12  are arranged at the centers of the coil bobbins  10 C. Further, at the pre-assembly step of the correction coil holding portion  10 , the coils  13  for correction of the convergence characteristic are arranged on the surface, on the separator main body  2  side, of the flange  10 B, the terminal board  14  is arranged on the terminal board holding portion  10 E, and lead wires of these coils  8  and  13  are connected to the terminal board  14 . Thus, the pre-assembly of the correction coil holding portion  10  is accomplished. 
     In the assembly of the deflection yoke of this embodiment, a horizontal deflection coil is wound using a die and a vertical deflection coil is wound around a specific core, separately from the above pre-assembly steps. As shown in FIG. 2, in a state in which the horizontal deflection coil is arranged inside the separator main body portions  4  and  5 , the bobbin  9  and the correction coil holding portion  10  are sequentially integrated with the separator main body portions  4  and  5 . Thus, the various components pre-assembled are integrated with each other, to form the separator  1 . 
     In this deflection yoke, since the neck portion  3  and the separator main body  2  are separately formed as described above, restricting conditions in design, for example, the releasing direction of a die and the fluidity of a resin, can be relaxed. The configurations of the neck portion  3  and the separator main body portions  4  and  5  can be thus correspondingly simplified, and the productivity in injection-molding can be improved. The period of time required for preparation of a die can be also shortened. 
     The neck portion  3  can be pre-assembled separately from the separator main body  2 , to correspondingly simplify the assembling works of the deflection yoke. 
     At the step of integrating the neck portion  3  with the separator main body  2 , the bobbin  9  is held between the separator main body portions  4  and  5 , and the claws  6 A and the engagement portions  6 B arranged on the flanges  4 A,  5 A and the like of the separator main body portions  4  and  5  are pressedly engaged with each other. Accordingly, the bobbin  9  can be simply assembled with the separator main body portions  4  and  5 . 
     When the separator main body portions  4  and  5  are integrated with the neck portion  3  while holding it therebetween, the circular-arc portions of the flanges  4 B and  5 B of the separator main body portions  4  and  5  are meshed with the groove  9 A of the bobbin  9  (see FIG. 5) and the projections  4 D and  5 D formed on the circular-arc portions are engaged with the openings  9 B formed in the groove  9 A. This makes it possible to prevent the bobbin  9  of the neck portion  3  from turning around the tube axis and the displacement of the bobbin  9  in the direction along the tube axis. 
     The bobbin  9  is then inserted in the correction coil holding portion  10  to be integrated therewith. The band  18  is attached around the bobbin  9  via the projection  9 C, and the lead wires of the coils  15 A,  15 B,  15 C, . . . on the bobbin  9  are connected to the terminal board  14 . 
     At this time, the displacement of the band  18  is prevented by the projection  9 C of the bobbin  9 , and the displacement of the correction coil holding portion  10  in the direction along the tube axis is prevented by the band  18  and the flanges  4 B and  5 B of the separator main body portions  4  and  5 . The flanges of the coil bobbins  10 C formed on the correction coil holding portion  10  are clamped in the U-shaped walls  4 E and  5 E formed in the separator main body portions  4  and  5 , to prevent the turning of the correction coil holding portion  10  around the tube axis. 
     In the deflection yoke thus assembled, the correction coils  13  are arranged on the surface, on the separator main body  2  side, of the flange  10 B (see FIG. 3) and the outsides of the coils  15 A,  15 B,  15 C, . . . are covered with the correction coil holding portion  10 , and accordingly, an accident such as erroneous contact of an operator with the coils  13  and the coils  15 A,  15 B,  15 C, . . . can be prevented. Further, since such an accident can be prevented without an additional protective mechanism using such a cover, heat radiation from the coils  13  and the coils  15 A,  15 B,  15 C, . . . is improved. 
     With this configuration, the separator main body formed into the approximately funnel shape similar to the contour of the horizontal deflection coil is formed separately from the approximately cylindrical neck portion for holding the horizontal deflection coil and the vertical deflection coil on the neck of the cathode-ray tube, and the separator main body and the neck portion are assembled with each other, to form the separator. Accordingly it is possible to relax the restricting conditions in design, for example, the releasing direction of a die and the fluidity of a resin and thereby simplify the configurations of the neck portion and the separator main body, and also to improve the productivity in injection-molding and shorten the period of time for preparation of a die. Since the neck portion can be pre-assembled separately from the separator main body, the assembling works of the deflection yoke can be correspondingly simplified. A neck portion different in shape depending on the kind of the deflection yoke can be assembled with the separator main body according to this embodiment, and also a neck portion having the coils  15 A,  15 B,  15 C, . . . different in characteristic can be assembled with the separator main body of this embodiment. As a result, it is possible to produce a larger number of types deflection yokes using a smaller number of dies. In addition, since the combination of the neck portion and the separator main body can be changed, it is possible to improve the design efficiency. 
     In this embodiment, the separator main body is composed of the separator main body portions divided along a virtual plane containing the tube axis of the cathode-ray tube and the neck portion is held between the separator main body portions to form the separator, and consequently, the deflection yoke can be simply assembled. 
     The displacement of the bobbin  9  can be prevented by a restricting mechanism due to engagement of the projections  4 D and  5 D of the separator main body portions  4  and  5  with the openings  9 B of the bobbin  9  and another restricting mechanism due to meshing of the circular-arc portions of the flanges  4 B and  5 B of the separator main body portions  4  and  5  with the groove  9 A of the bobbin  9 . As a result, a change with elapsed time and a variation in convergence characteristic and the like can be reduced irrespective of the simple assembling configuration in which the neck portion and the separator main body separately formed are assembled. 
     The displacement of the correction coil holding portion  10  can be prevented by a restricting mechanism due to holding of the correction coil holding portion  10  from the upper and lower sides by the band  18  attached around the bobbin  9  via the projection  9 C and the flanges  4 B and  5 B of the separator main body portions  4  and  5 , and another restricting mechanism due to clamping of the flanges of the coil bobbins  10 C formed on the correction coil holding portion  10  in the walls  4 E and  5 E formed on the flanges  4 B and  5 B. As a result, a change with elapsed time and a variation in convergence characteristic and the like can be reduced irrespective of the simple assembling configuration in which the neck portion and the separator main body separately formed are assembled. 
     Since the coils  8  and  13  and the coils  15 A,  15 B,  15 C, . . . for correction of the convergence characteristic are arranged on the neck portion  3 , the works for mounting these coils can be performed in the separate steps. This makes it possible to correspondingly simplify the assembling works of the deflection yoke, and hence to shorten the time required for the assembly of the deflection yoke. 
     In the above arrangement of the coils, by arranging the coils  13  on the surface, on the separator main body  2  side, of the flange  10 B and by covering the coils  15 A,  15 B,  15 C, . . . wound on the bobbin  9  with the correction coil holding portion  10 , the coils  13  and the coils  15 A,  15 B,  15 C, . . . can be prevented from being exposed. As a result, an accident such. as an operator&#39;s erroneous contact with these coils can be effectively prevented and heat radiation from these coils can be improved with a temperature rise of the neck portion reduced. 
     Since the terminal board  14  is held on the correction coil holding portion  10  and the coils  8  and  13  are wired to the terminal board  14 , the wiring works for the coils  8  and  13  can be performed at the pre-assembly step for the correction coil holding portion  10 , to correspondingly simplify the assembling works of the deflection yoke. 
     In the above embodiment, description has been made of the restricting mechanisms, for preventing various displacements, due to engagement of the projections  4 D and  5 D of the separator main body portions  4  and  5  with the openings  9 B of the bobbin  9  and due to meshing of the circular-arc portions of the flanges  4 B and  5 B of the separator main body portions  4  and  5  with the groove  9 A of the bobbin  9 . However, the above description is for illustrative purposes only and it is to be understood that various other restricting mechanisms may be widely used as needed. 
     In the above embodiment, description has been made of the assembling step in which the bobbin  9  is integrated with the separator main body portions  4  and  5  and then the correction coil holding portion  10  is mounted to the unit thus integrated. However, the present invention is not limited thereto. For example, the bobbin  9  may be first integrated with the correction coil holding portion  10  to form the neck portion  3 , followed by integration of the neck portion  3  with the separator main body portions  4  and  5 . 
     Also in the above embodiment, description has been made of the configuration in which the neck portion  3  is composed of the bobbin  9  and the correction coil holding portion  10 . However, the present invention is not limited thereto. For example, the neck portion may be formed of a single molded part as needed. 
     Although in the above embodiment, description has been made of a configuration arranging the horizontal deflection coil that prepared by die winding inside the separator, the present invention is not limited thereto but may be widely applied, for example, to a separating winding system employing the horizontal deflection coil is prepared by winding separately, that is the so-called section winding. 
     In the above embodiment, description has been made of the configuration in which the separator main body is formed into the shape similar to the contour of the horizontal deflection coil prepared by die winding for arranging the horizontal deflection coil inside the separator; however, the present invention is not limited thereto but may be widely applied, for example, to the configuration in which the vertical deflection coil is formed into a saddle shape. Further, a separator in which the saddle-shaped vertical deflection coil is arranged may be composed of a separator main body and a neck portion formed separately from the separator main body. In this case, the separator main body is formed into a shape similar to the contour of the vertical deflection coil.