Abstract:
The present invention relates to a deflection yoke. According to the invention, in particular, anti-release means is provided in upper hook pieces formed in sides of a rear cover thereby preventing a printed circuit board from easy separation from the rear cover in fixing therebetween so that the assembling ability and productivity can be enhanced.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a deflection yoke, in particular, which can improve an assembly structure of a printed circuit board thereby preventing release thereof while enhancing the productivity.  
           [0003]    2. Description of the Prior Art  
           [0004]    In general, a Cathode Ray Tube (CRT) in a television or a monitor has a deflection yoke for correctly deflecting RGB beams scanned from an electron gun to a fluorescent screen applied on a screen of the CRT. Such a deflection yoke as one of the most important magnetic components in the CRT serves to deflect the electron beams from the electron gun so that electric signals transmitted in time sequence can be reproduced as images on the screen of the CRT.  
           [0005]    In other words, since the electron beams projected from the electron gun directly move onto the screen via a high voltage to light only central phosphors in the screen, the deflection yoke externally deflects the electron beams in the order of scanning. Here, the deflection yoke forms a magnetic field to deflect the electron beams correctly to the fluorescent screen applied on the screen of the CRT based on the fact that the electrons are forced to change the path thereof while passing through the magnetic field.  
           [0006]    [0006]FIG. 1 is a side elevation view for showing a general CRT. As shown in FIG. 1, a deflection yoke  4  is placed in an RGB electron gun section  3  of the CRT  1  to deflect electron beams scanned from an electron gun  3   a  to a fluorescent screen applied on a screen surface  2 .  
           [0007]    Such a deflection yoke  4  comprises coil separator  10  constituted by a pair of symmetric upper and lower parts which are coupled into one unit.  
           [0008]    The coil separator  10  is provided to insulate a horizontal deflection coils  15  and a vertical deflection coils  16  while assembling the positions thereof in a suitable degree, and comprised of a screen portion  11   a  for being coupled to a screen surface side of the CRT  1 , a rear cover  11   b  and a neck portion  12  integrally extended from a central surface of the rear cover  11   b  for being coupled to the electron gun section  3  of the CRT  1 .  
           [0009]    The coil separator  10  is respectively provided in the inner and outer peripheries with the horizontal deflection coils  15  and the vertical deflection coils  16  for forming a horizontal magnetic field and a vertical magnetic field via externally applied power.  
           [0010]    Further, a pair of ferrite cores  14  made of a magnetic substance are installed to wrap the vertical deflection coil  16  to strengthen a vertically deflected magnetic field generated from the vertical deflection coil  16 .  
           [0011]    The deflection yoke  4  configured like this is installed in the neck portion  12  of the CRT  1 , and when the horizontal deflection coil  15  and the vertical deflection coil  16  are applied with a sawtooth wave pulse, generates the magnetic field based on the Fleming&#39;s left hand rule to deflect the RGB electron beams emitted from the electron gun  3   a  of the CRT for determination of scanning positions on the screen through.  
           [0012]    Meanwhile, the deflection yoke as shown in FIG. 1 is classified into a saddle-saddle type deflection yoke as shown in FIGS. 2 and 3 and a saddle-toroidal type deflection yoke as shown in FIGS. 4 and 5 according to the winding structure of the coils.  
           [0013]    In this case, the saddle-saddle type deflection yoke as shown in FIGS. 2 and 3 comprises saddle type deflection coils  15  installed in the upper and lower sides of the inner periphery of a screen portion of a substantially conical coil separator and saddle type vertical deflection coils  16  installed in right and left sides of the outer periphery thereof.  
           [0014]    In order to strengthen the magnetic field of the vertical deflection coils  16 , the coil separator  10  is provided in the outer periphery of the screen portion  11   a  with a substantially cylindrical ferrite core  14 .  
           [0015]    Further, around the outer periphery of the neck portion  12  of the coil separator  10  is provided a coma-free coil (not shown) for compensating coma generated from the vertical deflection coils  16 .  
           [0016]    [0016]FIGS. 4 and 5 show a general saddle-toroidal type deflection yoke. In the saddle-toroidal type deflection yoke, horizontal deflection coils  15  are installed in the upper and lower sides of the inner periphery of a screen portion  11   a  of a substantially conical coil separator  10 , a substantially cylindrical ferrite core  14  is provided in the outer periphery, and vertical deflection coils  16  are wound along the upper and lower sides of the ferrite core  14 .  
           [0017]    Further, around the outer periphery of a neck portion  12  of the coil separator  10  is additionally installed a coma-free coil (not shown) for compensating coma generated from the vertical deflection coils  16 .  
           [0018]    Besides, each of the saddle-saddle type and saddle-toroidal type deflection yokes has a printed circuit board installed in one side of the coil separator  10  for supplying power to the foregoing horizontal deflection coils  15  and the vertical deflection coils  16 .  
           [0019]    [0019]FIGS. 6 and 7 show an assembly structure of a printed circuit board in a deflection yoke of the prior art. As shown in FIGS. 6 and 7, a coil separator  10  has a rear cover  11   b  coupled with the printed circuit board  100  for electrically connecting deflection coils and various electric instruments.  
           [0020]    The printed circuit board  100 , as shown in FIG. 6, comprises slide grooves  110  formed in an upper part with a predetermined interval and through-holes  120  formed at a predetermined interval under the slide groove  110 , in which the slide grooves  110  and the through-holes  120  are typically provided in a pair. Mean while, as shown in FIG. 6, each of the slide grooves  110  has a U-shape, and each of the through-holes is provided as a substantially rectangular hole.  
           [0021]    Such a printed circuit board  100  is fitted and coupled into a number of hook pieces  200  provided on the rear cover  11   b , in which the hook pieces  200  are constituted by upper hook pieces  210  and lower hook pieces  220  respectively formed at positions corresponding to the slide grooves  110  and the through-holes  120 .  
           [0022]    In this case, the upper and lower hook pieces  210  and  220  are inserted into the slide grooves  110  and the through-holes  120  formed in the printed circuit board  100  to fix the printed circuit board to the rear cover  11   b . Such upper and lower hook pieces  210  and  220  have ribs r 1  and r 2  and triangular piece-shaped protrusions p 1  and p 2  which are integrally formed at an interval corresponding to the thickness of the printed circuit board  100  for contacting to front and rear sides of the printed circuit board  100  for support thereof.  
           [0023]    Meanwhile, the protrusions p 1  and p 2  are projected from the leading ends of the upper and lower hook pieces  210  and  220  in triangular shape and have sizes that allow interference fit into the slide grooves  110  and the through-holes  120 , and in particular, the protrusions p 1  in the upper hook pieces  210  are projected as opposed to the protrusions p 2  in the lower hook pieces  220 . Further, the ribs r 1  and r 2  are projected at positions distanced from the protrusions p 1  and p 2  at an interval corresponding to the thickness of the printed circuit board.  
           [0024]    The upper and lower hook pieces  210  and  220  with the foregoing protrusions pl and p 2  and the ribs r 1  and r 2  have an interval that is slightly wider than that of the pair of slide grooves  110  and the pair of through-holes  120  for enabling elastic fastening thereof.  
           [0025]    The conventional deflection yoke configured as above can be fixed through insertion of the slide grooves  110  and the through-holes  120  of the printed circuit board  100  into the upper and lower hook pieces  210  and  220  which are integrally projected from the rear cover  11   b.    
           [0026]    However, in the convention deflection yoke like this, the printed circuit board  100  and the rear cover  11  are coupled through a fitting structure, in which assembly thereof is extraordinarily difficult due to the structures of the upper and lower hook pieces  210  and  220 , the slide grooves  110  and through-holes  120  so that a problem is incurred that the workability and the productivity are degraded.  
           [0027]    In other words, when the printed circuit board  100  is assembled to the rear cover  11   b , as shown in FIG. 7, the lower end of the printed circuit board  100  is moved toward the lower hook pieces  220  as the upper end thereof is inclined at a certain angle toward the upper hook pieces  210  and temporarily supported in this posture. In this case, the slide grooves  110  of the printed circuit board  100  may not maintain stable support from the upper hook pieces  210  thereby tending to be easily released or separated.  
           [0028]    Therefore, in carrying out the processes of assembly, an operator should pay considerable attention so that the slide grooves  110  may not be separated from the upper hook pieces  210  when the lower end is displaced toward the lower hook pieces  220  as the upper end of the printed circuit board  100  is temporarily assembled, so that the workability and productivity are degraded in a large margin as drawbacks.  
         SUMMARY OF THE INVENTION  
         [0029]    Accordingly, the present invention has been proposed to solve the foregoing problems of the prior art and it is an object of the invention to provide a deflection yoke which can prevent release of a printed circuit board in fixing the same on a rear cover thereby enhancing the assembling ability and the productivity.  
           [0030]    According to an embodiment of the invention to solve the foregoing object, it is provided a deflection yoke, comprising: a coil separator a screen portion coupled to a screen surface of a CRT, a rear cover and a neck portion extended from a central surface of the rear cover for being coupled to an electric gun of the CRT; horizontal and vertical deflection coils provided in the inner and outer peripheries of the coil separator for forming horizontally and vertically deflected magnetic fields; a printed circuit board coupled to the rear cover of the coil separator, and having a number of slide grooves with a certain size of separator piece in an upper part, the slide grooves being connected to an edge, and a plurality of through-holes at a certain interval under the slide grooves; upper hook pieces projected from a side of the rear cover, each of the upper hook pieces having a rib at one ends contacting to one side of the printed circuit board and a protrusion for penetrating one of the slide grooves to contact to aid printed circuit board; lower hook pieces provided at one sides of the upper hook pieces, each of the lower hook pieces having a rib and a protrusion for penetrating the through-holes of the printed circuit board to support both sides thereof; and anti-release means for projecting the protrusions of an adjacently arranged pair of the upper hook pieces to a mutually opposed direction to supportingly receive the separator piece provided between a pair of the slide grooves.  
           [0031]    It is preferred that the anti-release means are anti-release fitting lugs integrally extended from the protrusions of the upper hook pieces.  
           [0032]    According to another embodiment of the invention to solve the foregoing object, it is provided a deflection yoke, comprising: a coil separator a screen portion coupled to a screen surface of a CRT, a rear cover and a neck portion extended from a central surface of the rear cover for being coupled to an electric gun of the CRT; horizontal and vertical deflection coils provided in the inner and outer peripheries of the coil separator for forming horizontally and vertically deflected magnetic fields; a printed circuit board coupled to the rear cover of the coil separator, and having a number of slide grooves with a certain size of separator piece in an upper part, the slide grooves being connected to an edge, and a plurality of through-holes at a certain interval under the slide grooves; upper hook pieces projected from a side of the rear cover, each of the upper hook pieces having a rib at one ends contacting to one side of the printed circuit board and a protrusion for penetrating one of the slide grooves to contact to the printed circuit board; lower hook pieces provided at one sides of the upper hook pieces, each of the lower hook pieces having a rib and a protrusion for penetrating the through-holes of the printed circuit board to support both sides thereof; and anti-release means for mutually connecting the protrusions of an adjacently arranged pair of the upper hook pieces to supportingly receive the separator piece between the pair of upper hook pieces.  
           [0033]    It is preferred that the anti-release means is an anti-release connector piece in which the protrusions of the pair of upper hook pieces are connected in a mutually opposed direction.  
           [0034]    According to still another embodiment of the invention to solve the foregoing object, it is provided a deflection yoke, comprising: a coil separator a screen portion coupled to a screen surface of a CRT, a rear cover and a neck portion extended from a central surface of the rear cover for being coupled to an electric gun of the CRT; horizontal and vertical deflection coils provided in the inner and outer peripheries of the coil separator for forming horizontally and vertically deflected magnetic fields; a printed circuit board coupled to the rear cover of the coil separator, and having a number of slide grooves with a certain size of separator piece in an upper part, the slide grooves being connected to an edge, and a plurality of through-holes at a certain interval under the slide grooves; upper hook pieces projected from a side of the rear cover, each of the upper hook pieces having a rib at one ends contacting to one side of the printed circuit board and a protrusion for penetrating one of the slide grooves to contact to the printed circuit board; lower hook pieces provided at one sides of the upper hook pieces, each of the lower hook pieces having a rib and a protrusion for penetrating the through-holes of the printed circuit board to support both sides thereof; and anti-release means for projecting the protrusions of the upper hook pieces in an opposed direction to contact to one sides of the slide grooves.  
           [0035]    It is preferred that the anti-release means are anti-release fitting lugs which are integrally provided to the protrusions of the upper hook pieces.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0036]    [0036]FIG. 1 is a side elevation view for showing a general CRT;  
         [0037]    [0037]FIGS. 2 and 3 are front and plan sectional views for showing a general saddle-saddle type deflection yoke;  
         [0038]    [0038]FIGS. 4 and 5 are front and plan sectional views for showing a general saddle-toroidal type deflection yoke;  
         [0039]    [0039]FIGS. 6 and 7 show an assembly structure of a printed circuit board in a deflection yoke of the prior art;  
         [0040]    [0040]FIGS. 8 and 9 are perspective and plan views for showing an embodiment of a rear cover and a printed circuit board in a deflection yoke of the invention;  
         [0041]    [0041]FIGS. 10 and 11 are perspective and plan views for showing another embodiment of a rear cover and a printed circuit board in a deflection yoke of the invention;  
         [0042]    [0042]FIGS. 12 and 13 are perspective and plan views for showing further another embodiment of a rear cover and a printed circuit board in a deflection yoke of the invention; and  
         [0043]    [0043]FIG. 14 is a side elevation view for showing assembly of a rear cover and the printed circuit board in a deflection yoke of the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0044]    First, referring to FIGS.  1  to  5 , each of general deflection yokes  4  is placed in an RGB electron gun section  3  of a CRT  1  for deflecting electron beams scanned from an electron gun  3   a  to a fluorescent screen coated on a screen surface  2 , and generally classified into a saddle-saddle type deflection yoke as shown in FIGS. 2 and 3 and a saddle-toroidal type deflection yoke as shown in FIGS. 4 and 5 according to the winding structure of coils.  
         [0045]    Such a deflection yoke  4  functions to deflect the electron beams that are projected from the RGB electron gun  3   a  installed in a neck portion  12  of the CRT  1  rightward, leftward, upward and downward to be collided on correct positions on the fluorescent surface of the CRT.  
         [0046]    [0046]FIGS. 2 and 3 show a general saddle-saddle type deflection yoke. As shown in FIGS. 2 and 3, the saddle-saddle type deflection yoke has saddle-type horizontal deflection coils  15  installed in upper and lower sides of the inner periphery of a screen portion  11   a  of a substantially conical-shaped coil separator  10  and saddle-type vertical deflection coil  16  installed in right and left sides of the outer periphery of the coil separator  10 .  
         [0047]    The coil separator  10  is provided in the outer periphery of the screen portion  11   a  with a substantially cylindrical ferrite core  14  for reinforcing a magnetic field of the vertical deflection coils  16 .  
         [0048]    Further, the coil separator  10  is provided around the outer periphery of the neck portion  12  with a coma-free coil (not shown) for compensating coma generated by the vertical deflection coils  16 .  
         [0049]    [0049]FIGS. 4 and 5 show a general saddle-toroidal type deflection yoke. As shown in FIGS. 4 and 5, the saddle-toroidal type deflection yoke has horizontal deflection coils  15  in upper and lower sides of the inner periphery of a screen portion  11   a , a substantially cylindrical ferrite core  14  in the outer periphery of the screen portion  11   a  and toroid-shaped vertical deflection coils  16  wound along upper and lower sides of the ferrite core  14 .  
         [0050]    Further, the coil separator  10  is additionally provided around the outer periphery of a neck portion  12  with a coma-free coil (not shown) for compensating coma generated from the vertical deflection coils  16 .  
         [0051]    In addition, each the saddle-saddle type and saddle-toroidal type deflection yokes is provided at one side of the coil separator  10  with a printed circuit board for supplying power to the foregoing horizontal deflection coils  15  and the vertical deflection coils  16 .  
         [0052]    Meanwhile, in each the foregoing deflection yokes  4 , the printed circuit board  100  is coupled to a side of a rear cover  11   b  of the coil separator  10  for electrically connecting the horizontal deflection coils  15 , the vertical deflection coils  16  and various electrical instruments, and externally supplied with power.  
         [0053]    FIGS.  8  to  14  are drawings for showing various embodiments for assembly of a rear cover and a printed circuit board according to the invention.  
         [0054]    As shown in FIGS.  8  to  14 , the printed circuit board  30  has a plurality of slide grooves  31  with a predetermined interval at both upper sides, in which each of the slide grooves  31  is provided in the form of a slit downwardly extended from the upper edge of the printed circuit board  30 . Such slide grooves  31  are provided in plural having the predetermined interval, and in a pair according to the invention.  
         [0055]    Further, the printed circuit board  30  is provided under the slide grooves  31  with a pair of through-holes  32 , each of which has a substantially rectangular shape.  
         [0056]    Like this, in positions corresponding to the slide grooves  31  and the through-holes in the printed circuit board  30 , a plurality of hook pieces  40  are provided in a rear cover  11   b  for enabling stable fixture with the printed circuit board  30 .  
         [0057]    In this case, the hook pieces  40  are generally constituted by upper hook pieces  41  corresponding to the slide grooves  31  and lower hook pieces  42  corresponding to the through-holes  32 .  
         [0058]    In this case, the upper hook pieces  41  are provided in a side of the rear cover  11   b  corresponding to the slide grooves of the printed circuit board  30 , and in a pair also for enabling respective insertion into the pair of slide grooves  31 . Further, the lower hook pieces  42  are provided under the slide grooves  31  in one side of the rear cover  11   b  corresponding to the foregoing through-holes  32  of the printed circuit board  30 .  
         [0059]    Meanwhile, as shown in the drawings, the upper hook pieces  41  and the lower hook pieces  42  are adapted to have protrusions p 1  and p 2  and ribs r 1  and  42  at a predetermined interval so that the upper hook pieces  41  and the lower hook pieces  42  can effect a supporting force as contacted to both sides of the printed circuit board while penetrated the slide grooves  31  and the through-holes  32 .  
         [0060]    In this case, the protrusions p 1  and p 2  are respectively projected with a predetermined size from the ends of the hook pieces  40 , and the ribs r 1  and r 2  are provided at predetermined positions with a predetermined interval from the protrusions p 1  and p 2  for supporting the other side of the printed circuit board  30  so as to prevent play of the printed circuit board  30  together with the protrusions p 1  and p 2 .  
         [0061]    In other words, the protrusions p 1  and p 2  and the ribs r 1  and r 2  contact to the front and rear sides of the printed circuit board about the slide grooves  31  and the through-holes  32  to prevent play of the printed circuit board  30 , and the protrusions p 1  and p 2  and the ribs r 1  and r 2  have an interval substantially proportional to the thickness of the printed circuit board  30 .  
         [0062]    Meanwhile, the mutual interval of the pair of upper hook pieces  41  and the lower hook pieces  42  configured as above is slightly wider than that of the pair of slide grooves  31  and the through-holes  32  so that the hook pieces  41  and  42  can be elastically inserted into the slide grooves  31  and the through-holes  32 .  
         [0063]    In the upper and lower hook pieces  41  and  42  configured as above, when the protrusions p 1  and p 2  in the ends penetrate the slide grooves  31  and the through holes  32 , one sides of the protrusions p 1  and p 2  contact to one sides of the printed circuit board  30 , and the ribs r 1  and r 2  having the predetermined interval from the protrusions p 1  and p 2  contact to the other side of the printed circuit board  30 .  
         [0064]    Therefore, the both sides of the printed circuit board  30  contact to the protrusions p 1  and p 2  and the ribs r 1  and r 2  of the hook pieces  41  and  42  about the slide grooves  31  and the through-holes  32  to prevent play of the printed circuit board  30  when coupled to the rear cover  11   b.    
         [0065]    Meanwhile, one side of the each protrusion p 1  is extendedly projected to provide anti-release means for easier assembly of the printed circuit board  30 .  
         [0066]    [0066]FIGS. 8 and 9 show an embodiment of the anti-release means in the deflection yoke according to the invention, in which the anti-release means has a predetermined size of space L 1  between the pair of hookpieces  41  and a separator piece L 2  provided between the pair of slide grooves  31  so that the separator piece L 2  can be inserted into the space L 1 .  
         [0067]    In the foregoing anti-release means, the protrusions p 1  in the adjacently arranged pair of upper hook pieces  41  are extended as opposed at a predetermined length to integrally provide anti-release fitting lugs  45 . In this case, each of the anti-release fitting lugs  45  may have the sectional shape of triangle, rectangle or circle.  
         [0068]    When the anti-release fitting lugs  45  are provided in the adjacent pair of upper hook  41 , the space L 1  for receiving the separator piece L 2  is formed as shown in FIG. 9 thereby preventing easy release of the printed circuit board  30  from the pair of upper hook pieces  41  during the assembly.  
         [0069]    [0069]FIGS. 10 and 11 show another embodiment of the anti-release means in the deflection yoke according to the invention. As shown in FIGS. 10 and 11, in the anti-release means may, the protrusions p 1  of the adjacently arranged pair of upper hook pieces  41  may be connected along a direction opposed to each other to provide an anti-release connector pin  46 .  
         [0070]    When the anti-release connector pin  46  is provided like this, a space L 1  is formed between the pair of upper hook pieces so that a separator piece L 2  can be inserted, such a configuration prevents the printed circuit board  30  from easy release from the rear cover  11   b  during the assembly thereof.  
         [0071]    Such anti-release means can be modified into various configurations if it has a structural feature of being integrally extended from the protrusions p 1  to contact to one sides of the slide grooves  31  of the printed circuit board  30  for prevention of release.  
         [0072]    As an instance, as shown in FIGS. 12 and 13, the anti-release means can be provided in the form of an anti-release protrusion  47  in which the protrusions p 1  are projected in a mutually opposed horizontal direction. The anti-release protrusion  47  has a configuration of contacting to one sides of the slide grooves  31  as in the foregoing embodiments to prevent release of the printed circuit board  30  from the upper hook pieces  31  during the assembly.  
         [0073]    In the deflection yoke of the invention configured as above, the printed circuit board is assembled according to the following processes. Hereinafter, the processes will be described in reference to the anti-release means shown in FIGS. 8 and 9 of the various embodiments of the invention.  
         [0074]    In order to assemble the foregoing printed circuit board  30  to the rear cover  11   b , as shown in FIG. 14, the separator piece L 2  formed in the upper end of the printed circuit board  30  is inserted into the space L 1  provided in the upper hook pieces  41  as the upper end of the printed circuit  30  is obliquely inclined toward the rear cover  11   b.    
         [0075]    In this case, as the separator piece L 2  of the printed circuit board  30  is inserted into the space L 1 , the printed circuit board is prevented from playing to other directions excepting for an insertion direction of the separator piece L 2 .  
         [0076]    In sequence, when the upper end of the printed circuit board  30  is temporarily fixed by the pair of upper hook pieces  41 , the rear end of the printed circuit board  31  is pivoted toward the rear cover  11   b  about the temporarily fixed portion, i.e., the upper hook pieces  41  and the slide grooves  31 .  
         [0077]    Therefore, the lower hook pieces  42  are inserted and coupled into the through-holes  32  while carrying out slightly elastic displacement along an inclined surface of the printed circuit board  30  and at the same time the upper end of the printed circuit board  30  is completely inserted and coupled to the upper hook pieces  41  by means of vertically positioning the printed circuit board  30  so that the processes of assembling the printed circuit board  30  are resultantly completed.  
         [0078]    According to the deflection yoke of the invention as described hereinbefore, when the processes of assembly are carried out as the printed circuit board is temporarily fixed to the rear cover, the upper hook pieces having the anti-release means prevent the printed circuit board from easy release or separation so that the overall workability and productivity of assembly are remarkably improved as advantages.