Abstract:
Disclosed is a deflection yoke which provides a structure for uniformly supporting a PCB on a rear cover of the deflection yoke in order to prevent any damage due to the assembling force when the PCB is assembled onto the rear cover.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a deflection yoke, in particular, which provides an improved structure of a PCB in order to prevent any damage due to assembling force.  
           [0003]    2. Description of the Related 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 toward a fluorescent screen applied on a screen of the CRT. Such a deflection yoke functions as one of the most important magnetic components in the CRT 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 linearly move toward the screen under a high voltage to light only central phosphors in the screen, the deflection yoke externally deflects the electron beams in the order of scanning. The deflection yoke generates a magnetic field to deflect the electron beams correctly onto the fluorescent screen applied on the screen of the CRT based upon the fact that the electrons change their courses when they are forced from the magnetic field while passing through the same.  
           [0006]    [0006]FIG. 1 is a side elevation view illustrating 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  toward a fluorescent screen applied on a screen surface  2 .  
           [0007]    Such a deflection yoke  4  comprises a coil separator  10  constituted of a pair of symmetric upper and lower parts which are coupled into one unit. The coil separator  10  is provided to mutually insulate horizontal deflection coils  15  and vertical deflection coils  16  while assembling the same in place, and comprised of a screen section  11   a  for coupling with one side of a screen surface of the CRT  1 , a rear cover  11   b  and a neck section  12  integrally extended from a central surface of the rear cover  11   b  for coupling with the electron gun section  3  of the CRT  1 .  
           [0008]    In the inner and outer peripheries of the coil separator  10 , the horizontal deflection coils  15  and the vertical deflection coils  16  are respectively provided to generate horizontal and vertical magnetic deflections with an external power source.  
           [0009]    Further, a pair of ferrite cores  14  are installed to wrap the vertical deflection coils  16 . The ferrite cores  14  are made of a magnetic substance to strengthen the vertical magnetic deflection generated from the vertical deflection coils  16 .  
           [0010]    The deflection yoke configured as above is provided at one side with a Printed Circuit Board (PCB; not shown) to electrically connect with the horizontal deflection coils, the vertical deflection coils and various electric equipments.  
           [0011]    [0011]FIGS. 2 and 3 are front elevation views illustrating a coil separator coupled with a PCB of the prior art.  
           [0012]    As shown in FIGS. 2 and 3, the PCB  200  has slide grooves  210  provided in the upper section with a predetermined interval and through-holes  220  distanced under the slide grooves  210  with a certain space, in which the slide grooves  210  and the through-holes  220  are generally provided in pairs.  
           [0013]    In the meantime, the slide grooves  210  are U-shaped as shown in FIG. 3, and the through-holes  220  are substantially quadrangular.  
           [0014]    The PCB  200  is coupled with a number of hook pieces provided on a rear cover  11   b , in which the hook pieces are constituted of upper hook pieces  310  and lower hook pieces  320  provided in positions corresponding to the slide grooves  210  and the through holes  220 .  
           [0015]    The upper hook pieces  310  and the lower hook pieces  320  constructed as above are fit into the slide grooves  210  and the through holes  220  to fix the PCB  200  onto the rear cover  11   b .  
           [0016]    In the meantime, the upper hook pieces  310  and the lower hook pieces  320  are provided in positions which are substantially in the range of the diameter of the neck section  12 .  
           [0017]    However, such a conventional deflection yoke has a drawback that the PCB  20  is easily damaged at both ends due to the assembling force of a worker when it is assembled to the rear cover  11   b  as shown in FIG. 3. Since the pair of the upper hooks  310  and lower hooks  320  applying a supporting force to the PCB  200  are constructed within the diameter of the neck section  12 , the PCB  200  having the upper and lower hooks  310  and  320  is applied at a central portion thereof with the stable supporting force, but not at both sides of the upper end thereof. So, the both sides of the upper end are easily cracked and broken.  
           [0018]    Therefore, the worker is required to carry out the assembly work while heavily paying attention not to damage the upper both ends of the PCB  200  so that the workability and the productivity are degraded as a problem.  
         SUMMARY OF THE INVENTION  
         [0019]    Accordingly the present invention has been made to solve the above problems of the prior art and it is an object of the invention to provide a deflection yoke capable of securely supporting upper both ends of a PCB to prevent any damage due to the assembling force thereby to improve the assembling ability and the productivity.  
           [0020]    According to an aspect of the invention to obtain the above objects, it is provided a deflection yoke comprising: a coil separator having a screen section, a rear cover, the screen section and the rear cover being coupled to one side of a screen surface of a CRT, and a neck section extended from a central face of the rear cover for coupling with an electric gun section of the CRT; horizontal and vertical deflection coils provided in inner and outer peripheries of the coil separator for generating horizontal and vertical magnetic deflections; a plurality of fixtures projecting from sides of the rear cover with intervals proportional to the diameter of the neck section; a PCB having a plurality of holes in positions corresponding to the fixtures for receiving the same, the PCB electrically connecting the horizontal deflection coils and the vertical deflection coils; and a plurality of support pieces projecting from the sides of the rear cover having the fixtures projecting therefrom and with projected distal ends contacting with a side of the PCB for applying a supporting force.  
           [0021]    The invention is preferably characterized in that the fixtures are upper and lower hook pieces which are arranged with a vertical interval.  
           [0022]    Preferably, the invention is also characterized in that the plurality of holes in the PCB are slide-grooves recessed from edges and through-holes arranged under the slide grooves with an interval.  
           [0023]    Also, the invention is preferably characterized in that the support pieces are provided in positions adjacent to edges of the rear cover at sides of the fixtures.  
           [0024]    Preferably, the invention is also characterized in that the support pieces are provided in a pair for respectively supporting both sides of an upper part of the PCB.  
           [0025]    Preferably, the invention is also characterized in that the support pieces are integral to the rear cover. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    [0026]FIG. 1 is a side elevation view illustrating a CRT adopting a general deflection yoke;  
         [0027]    [0027]FIGS. 2 and 3 are front elevation views illustrating the assembled position of a PCB in a deflection yoke of the prior art; and  
         [0028]    [0028]FIGS. 4 and 5 illustrate the assembled posture of a PCB in a deflection yoke of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]    The following detailed description will present a preferred embodiment of the invention in reference to the accompanying drawings.  
         [0030]    [0030]FIGS. 4 and 5 illustrate the assembled posture of a PCB in a deflection yoke of the invention, in which the same reference numerals are used to designate the same or similar components as in FIG. 1.  
         [0031]    First, as shown in FIG. 1, the deflection yoke  4  has a substantially cone-shaped coil separator  10 , in which the coil separator  10  comprises a screen section  11   a  with a large diameter coupled to one side of the screen surface  2  of the CRT  1 , a rear cover  11   b  and a neck section  12 . The neck section  12  is integrally extended from a central face of the rear cover  11   b  to couple with the electron gun section  3  of the CRT  1 .  
         [0032]    Such a coil separator  10  is provided in the inner periphery with the horizontal deflection coil  15  for generating the horizontal magnetic deflection due to the external power source and in the outer periphery with the vertical deflection coil  16  also for generating the vertical deflection coil  16  for generating the vertical magnetic deflection due to the external power source. The horizontal deflection coil  15  and the vertical deflection coil  16  are mutually insulated while positioned in place.  
         [0033]    In the outer periphery of the coil separator  10 , the magnetic ferrite core  14  is constructed to surround the vertical deflection coil  16  to strengthen the magnetic deflections.  
         [0034]    The deflection yoke  4  constructed as above is provided with a PCB for electrically connecting various electric equipments such as the horizontal deflection coil  15  and the vertical deflection coil  16 .  
         [0035]    In this case, the PCB is fixed by fixtures provided at sides of the rear cover as shown in FIGS. 4 and 5, in which the fixtures are constituted of a number of upper and lower hook pieces.  
         [0036]    That is to say, as can be seen in the drawings, the PCB  20  fixed by the fixtures is so constructed to have U-shaped slide grooves  21  connected to the edge of the upper part of the PCB  20  and having a predetermined interval from each other and substantially quadrangle-shaped through-holes spaced downward from the slide grooves  21  with a predetermined distance.  
         [0037]    In this case, the interval between the pair of slide grooves  21  is so formed not to exceed the diameter of the neck section  12 , and the pair of through-holes  22  are formed in positions that do not exceed the diameter of the neck section  12  also.  
         [0038]    The PCB  20  as set forth above is coupled by fitting with the fixtures, i.e. the number of upper hook pieces  31  and the lower hook pieces  32 , which are provided at the sides of the rear cover  11   b . The upper hook pieces  31  and the lower hook pieces  32  are formed at such positions corresponding to the slide grooves  21  and the through-holes  22  of the PCB  20 .  
         [0039]    In the meantime, in the sides of the rear cover  11   b  having the upper hook pieces  31  and the lower hook pieces  32 , project a plurality of support pieces  40  which are substantial characteristic components of the invention. The support pieces  40 , as shown in FIG. 5, are integrally provided at the sides of the rear cover  11   b , from which the upper and lower hook pieces  31  and  32  project, in positions where they can respectively support both sides of the upper part of the PCB  20 .  
         [0040]    The pair of support pieces  40  project so much that they can contact with one side of the PCB  20  as shown in FIG. 4, in which the distal ends thereof preferably form flat faces so as to contact with the PCB  20  with large areas.  
         [0041]    In the meantime, the support pieces  40  are provided in the positions adjacent to the edge of the rear cover  11   b  at both sides of the fixtures, substantially exceeding the diameter of the neck section  12 . As the support pieces  40  are provided adjacent to the edge of the rear cover  11   b , the edge of the PCB  20  is applied with a supporting force from the support pieces  40 .  
         [0042]    In the meantime, although the support pieces  40  are illustrated as a pair of projections, the present invention is not restricted by the above construction. However, it shall be understood that the configuration and position of the support pieces  40  can be variously modified as long as they have structural characteristics which can apply secure supporting force to the upper both sides of the PCB  20  while buffering the assembling force of the PCB  20 .  
         [0043]    Hereinafter brief description will present a process of assembling the PCB in the deflection yoke of the invention as set forth above.  
         [0044]    First, the PCB  20  is arranged at the side of the rear cover  11   b  having the upper and lower hook pieces  31  and  32 . It is required to place the PCB  20  so that the upper and lower hook pieces  31  and  32  can be inserted into the slide grooves  21  and the through-holes  22 .  
         [0045]    Then, as the PCB  20  is moved toward the rear cover  11   b , the upper and lower hooks  31  and  32  are respectively fit into the slide grooves  21  and the through-holes  22  so that the PCB  20  is fixed on the rear cover  11   b.    
         [0046]    In the meantime, the supporting force from the pair of supporting pieces  40  provided at the both distal ends in the sides of the rear cover  11   b  is applied to the PCB  20  so as to prevent the damage due to the external force applied to the both upper ends of the PCB  20  in assembling the same.  
         [0047]    That is to say, since the pair of supporting pieces  40  are so constructed that the distal ends thereof closely contact with one side of the PCB  20 , the supporting force reduces the external force applied to the both upper ends of the PCB  20  in assembling the same, resultantly preventing any deformation or damage of the PCB  20  due to the assembling force.  
         [0048]    According to the deflection yoke of the invention as constructed above, the PCB is widely supported by the plurality of support pieces provided at the sides of the rear cover, and thus can be relieved from the damage due to the assembling force when it is assembled.  
         [0049]    Therefore, the invention improves the assembling ability of the PCB so as to provide an advantageous effect of enhancing the productivity.