KR20010002475A - Focus unbalance adjusting apparatus of cathode ray tube and cathode ray tube utilizing the same - Google Patents

Abstract

PURPOSE: A device for adjusting the focus unbalance and a color cathode ray tube using the same are provided to compensate the cross section distortion of an electron beam by compensating the nonuniformity of the deflection force of the electron beam emitted from an electron gun, thereby improving the focus property of the electron beam landed in a fluorescent film. CONSTITUTION: In a device for adjusting a focus unbalance, a magnet field is provided, wherein the magnet field does not affect the cross section of the center electron beam from three electron beams emitted from an electron gun of a cathode ray tube and arranged in line, and the magnet field allows to transfer the locations of the electron beams. A magnet group forms a quadrupole magnet field which compensates the distortion of the electron beam in the both sides due to the nonuniform magnetic field of a deflection york.

Description

Focus unbalance adjusting apparatus of cathode ray tube and cathode ray tube utilizing the same}

The present invention relates to a cathode ray tube, and more particularly, to an apparatus for adjusting focus unbalance of a color cathode ray tube for adjusting the focus unbalance of an electron beam deflected by a deflection yoke and landing on a fluorescent film.

Typically, in the color cathode ray tube, three electron beams emitted from the electron gun enclosed in the neck portion are selectively deflected by the deflection yoke to excite the phosphor of the fluorescent film formed on the inner surface of the panel. In order to obtain a clear image, the electron beams must be accurately landed on each phosphor of the fluorescent film, but the deflection yoke causes pin-cushioned deflection and barrel deflection fields to be formed by vertical and horizontal deflection coils for self-convergence of the electron beam. do.

This non-uniform deflection magnetic field distorts the cross section of the electron beam when deflecting to each part of the screen surface of the electron beam. In more detail, the deflection magnetic field of the deflection yoke for deflecting the electron beam includes a pincushion magnetic field 11 formed by a horizontal deflection coil and a barrel magnetic field formed by a vertical deflection coil as shown in FIG. 12). However, as shown in the drawing, three electron beams emitted from an electron gun (not shown), that is, three electron beams for exciting red, green, and blue phosphors (hereinafter, R electron beam (R), G electron beam (G), and B electron beam (B)) Since they are arranged inline, the magnetic fields applied to the electron beams are not all the same. Accordingly, the R, G, B electron beams R, G, and B, which are subjected to deflection while passing through the non-uniform pincushion magnetic field 11 and the barrel magnetic field 12, land on the fluorescent film of the panel (not shown). In this case, the electron beam spot is crushed by the low lens effect, or as shown in FIG. 2, the R and B electron beams R and B located at both sides of the electron beam spot are changed in the size of the cross section of the electron beam at the periphery of the fluorescent film 100. For example, R, B electron beams (R) (B) located on both sides of the three electron beams, that is, R, B electron beams (R) emitted from the electron gun 40 to excite the red phosphor and the blue phosphor as shown in FIG. (B) tends to have a smaller cross section of the electron beam due to a difference in deflection force due to the pincushion magnetic field when deflecting in a direction away from the side where the electron beam is located (in the case of the B battery beam, the R electron beam side).

In order to solve such a problem, conventionally, the cross section of the electron beam emitted from the electron gun is distorted in the reverse direction of the nonuniform magnetic field direction of the deflection yoke, and the focal lengths of the electron beam scanned to the center of the fluorescent film and the electron beam scanned to the edge of the fluorescent film are different. A way to do this was presented.

The method of distorting the cross section of the electron beam in the opposite direction of the non-uniform magnetic field has an electron lens (not shown) provided between the electrodes of the electron gun by having different focusing and diverging forces respectively acting in the vertical direction and the horizontal direction. The cross section of the electron beam passing through) is distorted in the opposite direction to the direction distorted by the deflection yoke. However, since the electron lens distorting the electron beam is made by modifying the shape of the electron beam passing hole formed in the electrode of the electron gun, it is difficult to manufacture the electron gun. Therefore, there is a limit to deforming the cross section of the electron beam by using the difference between the focusing force and the diverging force of the electron lens as described above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and focus unbalance that can improve the focus characteristic of the electron beam landing on the fluorescent film by correcting the cross-sectional distortion of the electron beam by correcting the unevenness of the deflection force of the electron beam emitted from the electron gun. It is an object to provide a regulating device and a color cathode ray tube using the same.

An object of the present invention is to provide a color cathode ray tube capable of making the size of the electron beam spot uniform in typical fluorescent light.

1 is a view showing a magnetic field formed by the vertical and horizontal deflection coils of a general deflection yoke.

2 is a view showing the size of a cross section of an electron beam deflected by deflection yoke and landing in a horizontal direction of a fluorescent film in a conventional cathode ray tube.

3 is a view illustrating a state in which a conventional R, G, B electron beam is landed on a fluorescent film;

4 is a partial ablation side view showing a color cathode ray tube equipped with a focus unbalance adjusting device according to the present invention;

5 is a partial ablation perspective view of a deflection yoke equipped with a focus unbalance adjusting device according to the present invention;

FIG. 6 is a front view illustrating a focus unbalance adjusting device and shows a magnetic field by a magnet; FIG.

7 to 9 show magnetic field distribution by the focus unbalance compensation means;

10 is a view showing a cross-sectional change of the electron beam by the magnetic field distribution on both electron beams,

11 and 12 are views showing the movement trajectory of the electron beam by the lens of the electron gun and the compensation means;

13 is a graph showing the vertical just focusing state according to the fluorescent film position;

14 is a front view showing a focus unbalance adjusting device, showing a magnetic field by a magnet;

The present invention to achieve the above object,

A magnet field emitted from the electron gun of the cathode ray tube and capable of transferring the position of the electron beam without affecting the center electron beam cross section among the three electron beams arranged inline;

And magnet groups forming a quadrupole magnet field for compensating distortion of both electron beams due to a nonuniform magnetic field of the deflection yoke.

And the color cathode ray tube of the present invention for achieving the above object,

A panel having a fluorescent film formed thereon, a panel encapsulated with the panel and encapsulated with an electron gun, an electron gun mounted on the neck portion of the panel to emit three electron beams arranged in-line to excite the fluorescent film, and an electron gun mounted to the funnel A deflection yoke for deflecting the electron beam emitted from the

Distortion of both electron beams by non-uniform magnetic field of deflection yoke by forming magnet field and quadrupole magnet field which are installed on the outer circumferential surface of the neck portion or deflection yoke without affecting the center electron beam cross section of three electron beams Characterized in that it is provided with a focus unbalance adjusting device including magnet groups to compensate for.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 and 5 show an embodiment of a color cathode ray tube equipped with a focus unbalance adjusting device according to the present invention.

As shown in the drawing, the color cathode ray tube includes a panel 20 having a fluorescent film 21 formed on an inner surface thereof, and a neck portion 31 encapsulated with the panel 20 and provided with an electron gun 40 and a deflection yoke 34, respectively. ) And a funnel 30 having a cone portion 32. The deflection yoke 34 or the neck portion is provided with a magnet group 50 that is a focus unbalance adjusting device.

The magnet group 50, which is the focus unbalance adjusting device, is mounted on the electron gun side of the separator 34a when the magnet group 50 is mounted on the deflection yoke 34 of the electron beam due to the non-uniform magnetic field formed by the deflection yoke 34. Compensation for cross section distortion. When the focus unbalance compensator 50 is mounted on the neck part, the focus unbalance compensator 50 is fixed to an outer circumferential surface of the neck part opposite to the electrode on one side of at least two electrodes constituting the main lens of the electron gun by a separate fixing member (not shown). In the magnet group 50 is provided on the outer peripheral surface of the neck portion corresponding to the electrode located on the screen side.

The configuration of the magnet group as the focus unbalance adjusting device is shown in FIGS. 6 and 7.

Referring to the drawing, the compensator is a magnet field which transfers the position to the separator 34a of the deflection yoke without affecting the cross section of the central electron beam G among the three electron beams R, G and B emitted from the electron gun. And magnet groups 50 that form a quadrupole magnet field to compensate for distortion of both electron beams due to the nonuniform magnetic field of the deflection yoke 34.

The magnet group 50 includes first and second magnets 51 and 52 positioned above and below the central electron beam G, and third and fourth installed adjacent to the electron beams R and B on both sides. And mastnets 53 and 54. The first, second, third and fourth magnets 51 to 54 are made of an electromagnet having N and S poles.

The magnetic pole arrangement of the first, second, third and fourth magnets 51-54 constituting the magnet group 50 has the S pole of the first magnet 51 positioned above the central electron beam G. The north pole of the two magnets 52 is located below the central electron beam G. In addition, the north poles of the third and fourth magnets 53 and 54 are positioned to face the south poles of the first magnets 51, and the south poles of the third and fourth magnets 53 and 54 are formed. It is located at the bottom so as to face the north pole of the two magnets (52). Here, the first and second magnets 51 and 52 may be installed above and below the center electron beam G. However, the first and second magnets 51 and 52 may be installed above and below the electron beam through hole. When the electron beam emitted from the electron gun 40 is deflected by the deflection yoke 34 and scanned to the edge of the fluorescent film 21, the electron beam 40 deflects to the coils of the magnets 51-54 constituting the magnet group 50. A current synchronized with the signal is applied.

Referring to the operation employing the focus unbalance device configured as described above is as follows.

When the electron beam emitted from the electron gun 40 is deflected by the deflection yoke 34 and scanned to the edge of the fluorescent film 21, it is deflected to each coil of each magnet 51-54 constituting the magnet group 50. A current in which a current synchronized with a signal is synchronized is applied.

When a current is applied to the electromagnet coil, a magnet field is formed by each of the first and second magnets 51 and 52 and the second and fourth magnets 53 and 54. The magnetic field components of the magnet field are shown in Figs. As shown, the magnetic field component of the X-axis acts outward (FIG. 8), the magnetic field component of the Y-axis acts downward on the center electron beam side and the electron beams of both sides alternately act up and down (FIG. 9). And the magnetic field distribution in the combined X and Y directions acts largely downward on the central electron beam side and radially on both sides of the electron beam side as shown in FIG.

The forces on the electron beam passing through them by their magnetic field components are briefly represented by the vector components as shown in FIG. 10.

That is, when the electron beam is deflected toward the periphery of the fluorescent film, the B electron beam receives divergence force in the vertical direction and focusing force in the horizontal direction and is lengthened, and the R electron beam receives the focusing force in the vertical direction and divergence force in the horizontal direction, It is lengthened. Therefore, when the electron beam is deflected to the periphery of the fluorescent film by the deflection magnetic field, the size of the electron beam spot is compensated for.

In more detail, in the case of an electron gun using quadrupole, the effects of the quadrupole lens and the focusing lens on both sides of the electron gun are larger than the B electron beam located on the inside, and the R electron beam located on the outside becomes larger due to the uneven magnetic field of the deflection yoke. However, the magnet group 50 installed to compensate for the focus distortion phenomenon of the R and B electron beams can compensate for the trajectory (indicated by the dotted lines) of the electron beam shown in FIGS. 11 and 12.

As described above, the compensation lens 50L is formed by the quadrupole magnet field formed by the first, second, third, fourth and fourth magnets 51, 52, 53, and 54 of the magnet groups 50. Is made by.

As shown in FIG. 6, the quadrupole magnet field forming the correction lens includes N electrons of the first and second magnets 51 and 52 provided at upper and lower portions of the central electron beam or the central electron beam through-hole. The F1 magnet field formed in the vertical direction inside the R electron beam is formed by S, and the F2 magnet field is formed by the S pole of the first magnet and the N pole of the third magnet. The F3 magnet field is formed between the N pole of the second magnet and the S pole of the third magnet, and is formed outwardly under the electron beam cross section, and the F4 magnet field is formed by the N and S poles of the second magnet. It is formed on the outside of the vertical down.

As described above, the cross section of the R electron beam has an elongated shape as shown in FIG. 10 by the F1, F2, F3, and F4 magnet fields.

And the cross section of the B electron beam located on the side corresponding to the periphery of the B electron beam by the first, second, third and fourth magnets 51-54 as shown in FIG. The magnet fields of F5, F6, F7, and F8 are formed in the cross section of the electron beam so as to be horizontal.

As described above, the cross-sectional changes of the longitudinal and transverse shapes of the R and B electron beams are alternated depending on the scanning direction of the electron beam toward the left and right sides of the screen. The R and B electron beams having the cross section as described above are compensated for in size of the cross section when scanning to the left and right sides of the screen by the nonuniform magnetic field of the deflection yoke.

According to the experiments of the present inventors, as shown in FIG. 13, when comparing the vertical just focus voltages of R and B electron beams according to the positions of the fluorescent films, R, B electron beam spots R at the edges of the fluorescent film in the conventional electron gun are shown. ), But it can be seen that in the case of the electron gun employing the magnet group 50 of the present application, the R, B electron beam spot R1 (B1) becomes uniform in size.

As another embodiment of the present invention, as shown in FIG. 14, the auxiliary magnets 55 are disposed in the diagonal direction with respect to the center of the electron gun (not shown) between the first, second, third and fourth magnets 51 to 54, respectively. -58) is installed. The auxiliary magnets 55-58 are preferably such that the north pole is located on the upper side and the south pole is located on the lower side.

The quadrupole magnet field is formed around the R, B electron beam cross section by the first, second, third and fourth magnets 51-54 and the auxiliary magnets 55-58 configured as described above. . As an example, the quadrupole magnet field acting on the R electron beam is applied to the left and right sides of the electron beam cross section by the first and second magnets 51 and 52 and the third magnet 53. The magnet fields F6 and F7 are formed in the upper and lower portions of the R electron beam cross section by the fifth and sixth auxiliary magnets.

The distortion correction of the electron beam cross section and the electron beam focus by the F5-F8 magnet field formed as described above is the same as in the above embodiment.

As described above, in the focus unbalance compensation device of a color cathode ray tube according to the present invention, the electron beam emitted from the electron gun is corrected in advance by applying an inverse magnetic field to the electron beam to compensate for the influence of the uneven pin cushion magnetic field of the deflection yoke. This allows the distortion of to cancel each other out. As a result, it is possible to compensate the uneven state of the cross section of the electron beam as the electron beam is scanned to the left and right sides of the screen, thereby improving the focus characteristic. In addition, the focus balance compensator has an advantage of compensating for miss convergence of the electron gun.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it can be modified by those skilled in the art within the technical scope of the present invention. And the cathode ray tube device as described above is applicable to a monitor, a television receiver, and the like.

Claims (16)

A magnet field emitted from the electron gun of the cathode ray tube and capable of transferring the position of the electron beam without affecting the center electron beam cross section among the three electron beams arranged inline; An apparatus for adjusting focus unbalance of a color cathode ray tube, comprising magnet groups forming a quadrupole magnet field for compensating distortion of both electron beams due to a nonuniform magnetic field of deflection yoke. The method of claim 1, Wherein the magnet group includes first and second magnets positioned above and below the central electron beam, and third and fourth magnets installed adjacent to the electron beams on both sides of the magnet group. . The method according to claim 1 or 2, And the magnetic poles of the magnet groups are arranged such that the compensation directions of the electron beam distortions are opposite to each other when the two electron beams are deflected. The method of claim 3, The first magnet is located above the central electron beam through hole, the S pole is located above the central electron beam, the second magnet is located below the central electron beam through hole, and the N pole is located below the central electron beam. Color cathode tube, characterized in that the N pole of the third and fourth magnets installed adjacent to the two electron beams is located on the upper side facing the S pole of the first magnet and the S pole is located on the lower side facing the second magnet. Focus unbalance adjuster. The method of claim 1, The fifth and sixth magnets are respectively located between the first and third magnets and between the first and fourth magnets, and between the second and third magnets, and between the second and fourth magnets. And a seventh and eighth magnet respectively positioned between the magnets. The method of claim 5, And the fifth, six, seven, and eight magnet groups are installed in a diagonal direction with respect to the center of the electron gun. The method according to claim 5 or 6, The first magnet is positioned above the central electron beam through hole, the S pole is located above the central electron beam, the second magnet is located below the N pole, and the N pole is located below the through hole of the central electron beam. N, poles of the third and fourth magnets disposed adjacent to each other are positioned on the upper side opposite to the S pole of the first magnet, and the S poles of the third and fourth magnets are positioned on the lower side facing the second magnet. 7,8 magnet magnetic pole is the focus unbalance adjusting device of the color cathode ray tube, characterized in that the first, second, third, and fourth magnets are arranged so as to face different magnetic poles. A panel having a fluorescent film formed thereon, a panel encapsulated with the panel and encapsulated with an electron gun, an electron gun mounted on the neck portion of the panel to emit three electron beams arranged in-line to excite the fluorescent film, and an electron gun mounted to the funnel A deflection yoke for deflecting the electron beam emitted from the Distortion of both electron beams by non-uniform magnetic field of deflection yoke by forming magnet field and quadrupole magnet field which are installed on the outer circumferential surface of the neck portion or deflection yoke without affecting the center electron beam cross section of three electron beams Color cathode ray tube, characterized in that it comprises a focus unbalance adjustment device including a group of magnets to compensate. The method of claim 8, And the magnet group includes first and second magnets positioned above the electron beam of the middle child, and third and fourth magnets installed adjacent to the electron beams on both sides of the magnet group. The method according to claim 8 or 9, And the magnetic poles of the magnet groups are arranged such that the compensation directions of the electron beam distortions are opposite to each other when the two electron beams are deflected. The method of claim 10, The first magnet is located above the central electron beam through hole, the S pole is located above the central electron beam, the second magnet is located below and the N pole is located below the center electron beam, adjacent to both electron beams. The N-poles of the third and fourth magnets are arranged in the upper portion facing the S pole of the first magnet, and the S-pole is located in the lower portion facing the second magnet. The method of claim 9, The magnet group further includes fifth and sixth magnets located between the first magnet and the third and fourth magnets, and seventh and eighth magnets located between the second and third and fourth magnets. Focus unbalance adjusting device of the color cathode ray tube, characterized in that. The method of claim 12, And the fifth, six, seven, and eight magnet groups are installed in a diagonal direction with respect to the center of the electron gun. The method according to claim 11 or 12, wherein The first magnet is located above the central electron beam through hole, the S pole is located above the central electron beam, the second magnet is located below and the N pole is located below the central electron beam and is installed adjacent to both electron beams. The north pole of the third and fourth magnets is located at the upper side opposite to the S pole of the first magnet, and the south pole is located at the lower side opposite to the second magnet, and the magnetic poles of the 5, 6, 7, and 8 magnets are the first poles. Color cathode ray tube, characterized in that the 1,2,3,4 magnet and the different magnetic poles are disposed to face. The method of claim 12, Electron gun for color cathode ray tube, characterized in that the first to eighth magnets are made of an electromagnet to which a current synchronized with the deflection signal is applied The method of claim 8, And said magnet group is located on a side opposite to at least one of the electrodes forming the main lens of the electron gun.