Patent Publication Number: US-7211941-B2

Title: Deflection yoke and cathode-ray tube apparatus

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a deflection yoke, which is mounted on a funnel of a cathode-ray tube, for deflecting an electron beam in a horizontal direction and a vertical direction. The present invention also relates to a cathode-ray tube apparatus with the deflection yoke mounted thereon. 
   2. Description of the Related Art 
   A schematic configuration of a conventional deflection yoke (for example, see JP4(1992)-308634A) will be described with reference to  FIG. 6 . In  FIG. 6 , a Z-axis is a tube axis of a cathode-ray tube on which a deflection yoke  100  is mounted. The cross-sectional shape of the deflection yoke  100  is substantially symmetrical with respect to the Z-axis. Therefore,  FIG. 6  shows a partial cross-sectional view of the deflection yoke  100  on one side with respect to the Z-axis. 
   Reference numeral  11  denotes a saddle-type horizontal deflection coil,  12  denotes a vertical deflection coil wound around a ferrite core  14  in a toroidal shape, and  13  denotes an insulating frame made of resin for insulating the horizontal deflection coil  11  from the vertical deflection coil  12 . Reference numeral  20  denotes a plate-shaped deflection adjusting plate made of a magnetic material, for correcting a magnetic field generated by the horizontal deflection coil  11  and the vertical deflection coil  12 . 
   The deflection adjusting plate  20  is attached to be fixed to a predetermined position on an outer circumferential surface of the insulating frame  13  with an acetate tape  29  having a size larger than that of the deflection adjusting plate  20 . At this time, one surface of the deflection adjusting plate  20  comes into direct contact with the outer circumferential surface of the insulating frame  13 , and the other surface thereof is covered with the acetate tape  29 . After the deflection adjusting plate  20  is attached to the outer circumferential surface of the insulating frame  13 , an integrated body of the vertical deflection coil  12  and the ferrite core  14  is mounted so as to cover the insulating frame  13 . Thereafter, a hot-melt adhesive  25  is injected into a space between the integrated body of the vertical deflection coil  12  and the ferrite core  14 , and the insulating frame  13 . The ferrite core  14  and the insulating frame  13  are integrated with each other with the hot-melt adhesive  25 . 
   When a deflection current is supplied to the horizontal deflection coil  11  and the vertical deflection coil  12  of the deflection yoke  100 , the deflection adjusting plate  20  vibrates in accordance with an alternating magnetic field generated by the horizontal deflection coil  11  and the vertical deflection coil  12 . 
   In the conventional deflection yoke  100  shown in  FIG. 6 , the hot-melt adhesive  25  is of a quick drying type. Therefore, the hot-melt adhesive  25  is cured before spreading sufficiently to an entire region of the space between the ferrite core  14  and the insulating frame  13 . Thus, a gap may be formed between the acetate tape  29  and the hot-melt adhesive  25 . In this state, the force of binding the deflection adjusting plate  20  is relatively weak, so that the deflection adjusting plate  20  bumps into the insulating frame  13  and the hot-melt adhesive  25 , both of which have a high hardness, due to the vibration of the deflection adjusting plate  20 , thereby causing noise. 
   SUMMARY OF THE INVENTION 
   The present invention solves the above-mentioned problem of the conventional deflection yoke, and its object is to provide a deflection yoke and a cathode-ray tube apparatus with the generation of noise suppressed during the supply of a deflection current. 
   A deflection yoke of the present invention includes a horizontal deflection coil, a vertical deflection coil, an insulating frame made of an insulating material, a deflection adjusting plate attached to an outer circumferential surface of the insulating frame, and a ferrite core covering at least a part of an outer circumference of the insulating frame. The deflection adjusting plate is fixed to the outer circumferential surface of the insulating frame, under a condition of being surrounded by a high-soft resin material with a hardness of 10 to 60. 
   Furthermore, a cathode-ray tube apparatus of the present invention includes an envelope composed of a front panel and a funnel, an electron gun provided in a neck portion of the funnel, and a deflection yoke for deflecting an electron beam emitted from the electron gun in a horizontal direction and a vertical direction. The deflection yoke is the above-mentioned deflection yoke of the present invention. 
   These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial cross-sectional view showing a schematic configuration of a cathode-ray tube apparatus according to one embodiment of the present invention. 
       FIG. 2  is a partial cross-sectional view showing a schematic configuration of a deflection yoke according to Embodiment 1 of the present invention. 
       FIG. 3  is a partial cross-sectional view showing a schematic configuration of a deflection yoke according to Embodiment 2 of the present invention. 
       FIG. 4  is a partial cross-sectional view showing a schematic configuration of a deflection yoke according to Embodiment 3 of the present invention. 
       FIG. 5  is a front view showing an attachment state of a pair of auxiliary coil apparatuses in the deflection yoke according to Embodiment 3 of the present invention. 
       FIG. 6  is a partial cross-sectional view showing a schematic configuration of a conventional deflection yoke. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   According to the present invention, the deflection adjusting plate is surrounded by a high-soft resin material with a hardness of 10 to 60. Therefore, even when the deflection adjusting plate vibrates during driving, the deflection adjusting plate does not directly bump into the insulating frame and the hot-melt adhesive. This reduces the noise generated by the deflection yoke during driving significantly. 
   In the above-mentioned deflection yoke of the present invention, it is preferable that a low-soft adhesive with a hardness higher than that of the high-soft resin material is provided between the ferrite core, and the insulating frame and the high-soft resin material. According to this configuration, the noise generated by the deflection yoke due to the vibration of the ferrite core, which is likely to be conspicuous mainly when a vertical deflection current with a high frequency is supplied, can be reduced significantly. 
   Furthermore, the above-mentioned deflection yoke of the present invention may further include an auxiliary coil apparatus composed of a core made of a metallic magnetic substance and an auxiliary coil wound around the core, and attached to the insulating frame. In this case, it is preferable that a high-soft resin material with a hardness of 10 to 60 is interposed in at least a part between the auxiliary coil apparatus and the insulating frame. By providing the auxiliary coil apparatus, a high-precision image display can be performed. Furthermore, due to the presence of the high-soft resin material between the auxiliary coil apparatus and the insulating frame, the noise generated by the bump between the auxiliary coil apparatus and the insulating frame upon the application of an alternating current to the auxiliary coil can be reduced. 
   Hereinafter, the present invention will be described in detail by way of specific embodiments. 
   Embodiment 1 
     FIG. 1  is a view showing a configuration of a cathode-ray tube apparatus according to Embodiment 1 of the present invention. In  FIG. 1 , a Z-axis corresponds to a tube axis of a cathode-ray tube. In  FIG. 1 , a cross-sectional view and an outer appearance view are shown on an upper side and a lower side of the Z-axis, respectively. 
   A cathode-ray tube (CRT) includes an envelope composed of a front panel  2  and a funnel  3 , and an electron gun  4  provided in a neck portion  3   a  of the funnel  3 . A cathode-ray tube apparatus  1  includes the cathode-ray tube and a deflection yoke  10  mounted on an outer circumferential surface of the funnel  3 . On an inner surface of the panel  2 , a phosphor screen  2   a  is formed, in which respective phosphor dots (or phosphor stripes) of blue (B), green (G), and red (R) are arranged. A shadow mask  5  is attached to an inner wall surface of the front panel  2  so as to be opposed to the phosphor screen  2   a . The shadow mask  5  is made of a metallic plate with a number of substantially slot-shaped apertures, which are electron beam passage apertures, formed by etching, and three electron beams  7  emitted from the electron gun  4  pass through the apertures to strike predetermined phosphor dots. 
   Reference numeral  31  denotes a convergence and purity unit (CPU), which adjusts a static convergence and purity of electron beams at the center of a screen. The CPU  31  includes a dipole magnet ring, a quadrupole magnet ring, and a hexapole magnet ring. The respective dipole, quadrupole, and hexapole magnet rings are configured by stacking two annular magnets. 
   Reference numeral  30  denotes a substantially cylindrical holder for holding the CPU  31 . The holder  30  is externally placed on an outer circumference of the neck portion  3   a.    
   Reference numeral  32  denotes a pair of beam velocity modulation (BVM) coils provided so as to be substantially symmetrical with respect to a horizontal plane including the Z-axis with the horizontal plane interposed therebetween. Windings thereof are placed along the outer circumferential surface of the holder  30  to generate a magnetic field in a substantially vertical direction. 
   Reference numeral  33  denotes a magnetic substance ring for enhancing a magnetic field density of the BVM coils  32 . The magnetic substance ring  33  is held by the holder  30 . 
   The deflection yoke  10  deflects the three electron beams  7  emitted from the electron gun  4  in horizontal and vertical directions to allow them to scan the phosphor screen  2   a . The deflection yoke  10  of the present embodiment will be described with reference to  FIG. 2 . The cross-sectional shape of the deflection yoke  10  is substantially symmetrical with respect to the Z-axis. Therefore,  FIG. 2  shows a partial cross-sectional view of the deflection yoke  10  on one side with respect to the Z-axis. 
   The deflection yoke  10  includes a saddle-type horizontal deflection coil  11 , a toroidal vertical deflection coil  12 , and a ferrite core  14 . An insulating frame  13  made of an insulating material (e.g., resin) is provided between the horizontal deflection coil  11  and the vertical deflection coil  12 . The insulating frame  13  plays the role of maintaining electrical insulation between the horizontal deflection coil  11  and the vertical deflection coil  12 , as well as holding the horizontal deflection coil  11 . 
   A deflection adjusting plate  20  in a plate shape surrounded by a high-soft resin material  21  is placed at a predetermined position on an outer circumferential surface of the insulating frame  13 . The deflection adjusting plate  20  adjusts the distribution of a deflection magnetic field (in particular, a vertical deflection magnetic field) generated by the deflection yoke  10 . There is no particular limit on the material for the deflection adjusting plate  20 . For example, a high-permeability material (a metal plate, a sintered body of metal powder, etc.) with a permeability of 500 or more (preferably, 1000 or more) can be used. Herein, the permeability refers to an A.C. initial permeability (μ iac ) measured at a frequency of 100 kHz and a current of 0.5 mA. The deflection adjusting plate  20  is made of, for example, a silicon steel plate, a permalloy, or the like. The hardness (Asker hardness, Type C) of the high-soft resin material  21  is 10 to 60. 
   There is no particular limit on a method for attaching the deflection adjusting plate  20  surrounded by the high-soft resin material  21  to the insulating frame  13 . The deflection adjusting plate  20  can be fixed, for example, using an adhesive (or sticky) tape such as an acetate tape in the same way as in the conventional example. Furthermore, in the case where the high-soft resin material  21  itself has stickiness, it may be attached to the insulating frame  13  using its sticking force. 
   After the deflection adjusting plate  20  surrounded by the high-soft resin material  21  is attached to the outer circumferential surface of the insulating frame  13 , a hot-melt adhesive  25  is injected into a space between an integrated body of the vertical deflection coil  12  and the ferrite core  14 , and the insulating frame  13  in the same way as in the conventional example. The ferrite core  14  and the insulating frame  13  are integrated with each other with the hot-melt adhesive  25 . 
   The function of the deflection yoke  10  of Embodiment 1 thus configured will be described. 
   In the same way as in the conventional example, even in the present embodiment, the ferrite core  14  and the insulating frame  13  are fixed to each other by injecting the hot-melt adhesive  25  therebetween. The hot-melt adhesive  25  cannot completely fill the space between the ferrite core  14  and the insulating frame  13  due to its quick drying property, and a gap may be formed between the hot-melt adhesive  25  and the high-soft resin material  21  surrounding the deflection adjusting plate  20 . Thus, when a deflection current is supplied to the horizontal deflection coil  11  and the vertical deflection coil  12  of the deflection yoke  10 , the deflection adjusting plate  20  vibrates in the gap in accordance with an alternating magnetic field generated by the horizontal deflection coil  11  and the vertical deflection coil  12 . However, the periphery of the deflection adjusting plate  20  is covered with the high-soft resin material  21 , so that the deflection adjusting plate  20  does not directly bump into the insulating frame  13  and the hot-melt adhesive  25 , both of which have a high hardness. This reduces the noise generated by the deflection yoke  10  during driving significantly. 
   When the hardness (Asker hardness, Type C) of the high-soft resin material  21  is less than 10, the high-soft resin material  21  is too soft, which makes it difficult for the high-soft resin material  21  to hold the deflection adjusting plate  20  at a predetermined position of the insulating frame  13 . Consequently, a desired magnetic field adjusting effect by the deflection adjusting plate  20  cannot be obtained, whereby an image is degraded. Furthermore, when the hardness of the high-soft resin material  21  is larger than 60, the high-soft resin material  21  is too hard. Therefore, when the deflection adjusting plate  20  vibrates, the noise caused by the bump of the high-soft resin material  21  into the insulating frame  13  and the hot-melt adhesive  25  is increased. 
   In Embodiment 1, the space between the ferrite core  14  and the insulating frame  13  is filled with the hot-melt adhesive  25 . However, the present invention is not limited thereto. For example, the hot-melt adhesive  25  may be provided to only the vicinity of each opening on a small diameter side and a large diameter side in the space between the ferrite core  14  and the insulating frame  13 . 
   Embodiment 2 
     FIG. 3  shows a partial cross-sectional view of a deflection yoke according to Embodiment 2. The same elements as those of the deflection yoke  10  according to Embodiment 1 shown in  FIG. 2  are denoted with the same reference numerals as those therein, and the description thereof will be omitted here. 
   Embodiment 2 is different from Embodiment 1, in that the space between the integrated body of the vertical deflection coil  12  and the ferrite core  14 , and the insulating frame  13  is filled with a low-soft adhesive  22  with a hardness higher than that of the high-soft resin material  21 . The hot-melt adhesive  25  is provided to the vicinity of each opening on a small diameter side and a large diameter side between the ferrite core  14  and the insulating frame  13 , whereby the ferrite core  14  and the insulating frame  13  are integrated with each other. 
   As the low-soft adhesive  22 , for example, an epoxy resin adhesive, a silicon adhesive, resin containing a silyl group (e.g., “Super X8008” produced by Cemedine Co., Ltd.) can be used. 
   The function of the deflection yoke  10  of Embodiment 2 thus configured will be described. 
   It takes a longer time for the low-soft adhesive  22  to be cured, compared with the hot-melt adhesive  25 . Thus, during assembly of the deflection yoke  10 , the low-soft adhesive  22  is likely to spread sufficiently to an entire region of the space between the ferrite core  14  and the insulating frame  13 . Furthermore, the hardness of the low-soft adhesive  22  after being cured is lower than that of the hot-melt adhesive  25 . 
   In the case where the frequency of a deflection current supplied to the deflection yoke  10  is high, the vibration of the ferrite core  14  as well as that of the deflection adjusting plate  20  cannot be ignored. In the conventional deflection yoke  100 , when the ferrite core  14  vibrates, the ferrite core  14  and the peripheral members thereof bump into each other to generate noise. However, according to the present embodiment, the low-soft adhesive  22  between the ferrite core  14  and the insulating frame  13  is provided at a filling density higher than that of the hot-melt adhesive  25 , and has a low hardness. Therefore, the action of absorbing the vibration of the ferrite core  14  by the low-soft adhesive  22  is much larger than that by the hot-melt adhesive  25 . Thus, during driving, the noise generated by the deflection yoke  10  due to the vibration of the ferrite core  14  can be reduced significantly. 
   Furthermore, the high-soft resin material  21  surrounding the deflection adjusting plate  20  comes into contact with the low-soft adhesive  22 . Thus, compared with Embodiment 1 in which the high-soft resin material  21  comes into contact with the hot-melt adhesive  25  with a hardness higher than that of the low-soft adhesive  22 , the action of absorbing the vibration of the deflection adjusting plate  20  is increased. Therefore, during driving, the noise generated by the deflection yoke  10  due to the vibration of the deflection adjusting plate  20  can be reduced further. 
   In the present embodiment, the low-soft adhesive  22  and/or the hot-melt adhesive  25  do not need to fill the entire space between the ferrite core  14  and the insulating frame  13 , and a gap that is not filled with the adhesive may be present in the space. 
   Embodiment 3 
     FIG. 4  shows a partial cross-sectional view of a deflection yoke according to Embodiment 3. The same elements as those of the deflection yoke  10  according to Embodiment 1 shown in  FIG. 2  are denoted with the same reference numerals as those therein, and the description thereof will be omitted here. 
   Embodiment 3 is different from Embodiment 1, in that a pair of auxiliary coil apparatuses  40  are attached to a rear surface plate  13   a  of the insulating frame  13 , positioned on the CPU  31  side with respect to the horizontal deflection coil  11  in the Z-axis direction, so as to be symmetrical with respect to the Z-axis.  FIG. 5  shows a state in which the pair of auxiliary coil apparatuses  40  attached to the rear surface plate  13   a  of the insulating frame  13  are seen from the CPU  31  side. 
   Each auxiliary coil apparatus  40  is composed of a U-shaped core  41  made of a metallic magnetic substance, a bobbin  43  in a substantially hollow cylindrical shape placed on the core  41 , and an auxiliary coil  42  wound around an external circumferential surface of the bobbin  43 . The auxiliary coil  42  is connected in series or in parallel to the vertical deflection coil  12 , and generates a magnetic field synchronized with a vertical deflection magnetic field to correct the coma aberration in a beam spot shape on the phosphor screen  2   a  and the convergence of the three electron beams  7 . 
   The auxiliary coil apparatus  40  is attached to the insulating frame  13 , for example, by fitting or engaging the core  41  with respect to an attachment mechanism such as a groove, a hook, or the like formed in the insulating frame  13 . An adhesive may be provided between the auxiliary coil apparatus  40  and the attachment mechanism. 
   In the present embodiment, a high-soft resin material  50  with a hardness (Asker hardness, type C) of 10 to 60 is interposed between the auxiliary coil apparatus  40  and the insulating frame  13 . The function obtained by this configuration will be described. 
   When a current synchronized with the vertical deflection coil  12  is supplied to the auxiliary coil  42 , the core  41  vibrates in accordance with an alternating magnetic field generated by the auxiliary coil  42 . In the conventional deflection yoke in which the high-soft resin material  50  is not interposed, there is a problem that the vibration of the core  41  causes the auxiliary coil apparatus  40  and the insulating frame  13  to bump into each other to generate noise. According to the present invention, the high-soft resin material  50  is interposed between the auxiliary coil apparatus  40  and the insulating frame  13 . Therefore, the auxiliary coil apparatus  40  and the insulating frame  13  do not directly bump into each other, which can suppress the generation of noise during driving. 
   It is preferable that the hardness of the high-soft resin material  50  is 10 to 60. When the hardness of the high-soft resin material  50  is less than 10, the high-soft resin material  50  is too soft, which makes it difficult for the high-soft resin material  50  to maintain a desired shape for a long period of time. Furthermore, when the hardness of the high-soft resin material  50  is larger than 60, the high-soft resin material  50  is too hard. Therefore, the effect of suppressing noise when the core  41  vibrates is decreased. 
   There is no particular limit on the material for the high-soft resin material  50 , as long as it has a hardness of 10 to 60, and the same material as the high-soft resin material  21  surrounding the deflection adjusting plate  20  can be used. 
   The high-soft resin material  50  only need be provided at least in a portion that is effective for reducing noise generated when the core  41  vibrates, in a region where the auxiliary coil apparatus  40  is opposed to the insulating frame  13 . 
   In the above description, the case where the core  41  has a U-shape has been shown. However, the shape of the core is not limited thereto, and the core  41  may be in a I-shape, an E-shape, or the like. Furthermore, the pair of auxiliary coil apparatuses  40  only need be placed so as to sandwich the Z-axis (i.e., three electron beams  7 ), and can be attached on a vertical axis, a horizontal axis, or the like in accordance with a desired effect. 
   EXAMPLES 
   An example will be described in which the present invention is applied to a deflection yoke for a color cathode-ray tube apparatus with an diagonal size of 29 inches and an aspect ratio of a screen of 4:3. 
   Example 1 
   As shown in  FIG. 2 , the insulating frame  13  made of resin with the saddle-type horizontal deflection coil  11  wound on an inner circumferential surface, and the ferrite core  14  with the toroidal vertical deflection coil  12  wound were prepared. As the deflection adjusting plate  20 , a silicon steel plate (length: 30 mm, width: 5 mm, thickness: 0.5 mm) was used, which was deformed into a curved surface so as to be matched with the radius of curvature of the outer circumferential surface of the insulating frame  13  to which the deflection adjusting plate  20  is to be attached. As the high-soft resin material  21 , “ThreeSealer U0” (Asker hardness (Type C): 25±5 degrees in terms of a catalog value) produced by ThreeBond Co., Ltd., containing butyl rubber as a main component was cut into two sheets each having a size larger than the deflection adjusting plate  20 . 
   One sheet-shaped high-soft resin material  21  was attached to a predetermined position on the outer circumferential surface of the insulating frame  13 , using its stickiness. Then, the deflection adjusting plate  20  was attached to the high-soft resin material  21 , using the stickiness of the high-soft resin material  21 . Furthermore, the other sheet-shaped high-soft resin material  21  was attached to the deflection adjusting plate  20  attached to the high-soft resin material  21 . Thus, the deflection adjusting plate  20  was fixed to the outer circumferential surface of the insulating frame  13 , under the condition that the entire circumferential surface of the deflection adjusting plate  20  was covered with the high-soft resin material  21 . 
   After the ferrite core  14  was mounted so as to cover a part of the outer circumference of the insulating frame  13 , a hot-melt adhesive produced by Hirodine Co., Ltd. was injected to be cured in the space between the ferrite core  14  and the insulating frame  13 . Thus, the deflection yoke  10  shown in  FIG. 2  was obtained, in which the ferrite core  14  and the insulating frame  13  were fixed to each other with the hot-melt adhesive  25  provided therebetween. 
   The deflection yoke  10  was placed in an anechoic room, and a vertical deflection current of 50 Hz was supplied to the vertical deflection coil  12 . At this time, the noise generated by the deflection yoke  10  was measured with a microphone set at a position away from the deflection yoke  10  by 110 mm. Consequently, the noise level was 33.6 dB. 
   Example 2 
   An epoxy resin adhesive was applied to an inner circumferential surface of the ferrite core  14  as the low-soft adhesive  22 . Thereafter, the ferrite core  14  was mounted on the insulating frame  13 . Thus, the space between the ferrite core  14 , and the insulating frame  13  and the high-soft resin material  21  was almost filled with the low-soft adhesive  22 . Thereafter, the hot-melt adhesive  25  produced by Hirodine Co., Ltd. was provided to the vicinity of each opening on a small diameter side and a large diameter side between the ferrite core  14  and the insulating frame  13 . The deflection yoke  10  shown in  FIG. 3  was obtained in the same way as in Example 1 except for the above. 
   The noise generated when the deflection yoke  10  was driven was measured in the same way as in Example 1 except that the frequency of a vertical deflection current supplied to the vertical deflection coil  12  was set to be 100 Hz. Consequently, the noise level was 32.6 dB. 
   Comparative Example 1 
   One surface of the deflection adjusting plate  20  was brought into contact with the outer circumferential surface of the insulating frame  13 , and an acetate tape larger than the other surface of the deflection adjusting plate  20  was attached to the other surface, whereby the deflection adjusting plate  20  was fixed to the outer circumferential surface of the insulating frame  13 . The deflection yoke  100  shown in  FIG. 6  was obtained in the same way as in Example 1 except for the above. 
   The noise generated when the deflection yoke  10  was driven was measured in the same way as in Example 1, with the frequency of a vertical deflection current supplied to the vertical deflection coil  12  varied in two ways (i.e., 50 Hz and 100 Hz). Consequently, the noise level was 36 dB when the vertical deflection frequency was 50 Hz, and 37 dB when the vertical deflection frequency was 100 Hz. 
   When the vertical deflection frequency was 50 Hz, noise mainly caused by the vibration of the deflection adjusting plate  20  was generated in the deflection yoke  100  of Comparative Example 1. In contrast, in the deflection yoke  10  of Example 1, the noise level was reduced to 34 dB or less, which is considered to be the standard of low noise. 
   Furthermore, when the vertical deflection frequency was 100 Hz, in the deflection yoke  100  of Comparative Example 1, noise caused by the vibration of the ferrite core  14  as well as the vibration of the deflection adjusting plate  20  was generated. In contrast, in the deflection yoke  10  of Example 2, the noise level was reduced to 34 dB or less that was considered to be the standard of low noise. 
   The present invention is not limited to the above-mentioned embodiments and examples. For example, the shape and attachment position of the deflection adjusting plate  20  can be appropriately changed so as to adjust a deflection magnetic field. The vertical deflection coil  12  may be a saddle type, instead of a toroidal type. The present invention also is applicable to a cathode-ray tube apparatus of a monochromic display, instead of a color cathode-ray tube apparatus. 
   The applicable field of the deflection yoke and the cathode-ray tube apparatus with the deflection yoke mounted thereon of the present invention is not particularly limited. For example, the present invention can be used widely in a television, a computer display, or the like. 
   The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof The embodiments disclosed in this application are to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.