KR20020063326A - Electron gun and CPT therewith - Google Patents

Abstract

PURPOSE: An electron gun for color cathode ray tube and a color cathode ray tube having the same are provided to improve a focus characteristics of a peripheral part of a screen by forming different intervals among electron beam through-holes of electrodes. CONSTITUTION: Red, green, and blue electron beam through-holes(71R,71G,71B) are formed on a plate-shaped electron member(26b) of the third focus electrode. The red, green, and blue electron beam through-holes(71R,71G,71B) have a vertical side longer than a horizontal side, respectively. Red, green, and blue electron beam through-holes(72R,72G,72B) are formed on a cup-shaped electrode member(27a) of the fourth focus electrode. The red, green, and blue electron beam through-holes(72R,72G,72B) have a horizontal side longer than a vertical side, respectively. The cup-shaped electrode member(27a) of the fourth focus electrode has stepped portions in order to form different intervals among the electron beam through-holes.

Description

Electron gun for color cathode ray tube and color cathode ray tube provided with it {Electron gun and CPT therewith}

The present invention relates to an electron gun for a color cathode ray tube, and more particularly, for a color cathode ray tube which is arranged in an inline type and has a different distance between each electron beam passing holes of electrodes arranged in close proximity to each other to form a quadrupole lens. A dynamic focus electron gun and a color cathode ray tube having the same.

Typically, the electron gun for the color cathode ray tube is installed in the neck portion of the cathode ray tube to emit hot electrons, the performance of the cathode ray tube depends on the state in which the electron beam emitted from the electron gun is landing on the fluorescent film. Therefore, many electron guns have been developed to reduce the focus characteristic and the aberration of the electron lens so that the electron beam emitted from the electron gun can be accurately landed at the fluorescent point of the fluorescent film.

1 shows an example of a conventional electron gun.

This is the first, second, third, fourth and fifth focus electrodes 5, which are sequentially arranged adjacent to the cathode 2, the control electrode 3, and the screen electrode 4, which form an anterior triode, and form an auxiliary electrostatic lens. (6) (7) (8) (9) and the final acceleration electrode (10) provided adjacent to the fifth focus electrode (9) to form a main electron lens.

2 and 3, an elongated electron beam for forming a first quadrupole lens is formed on the emission side of the third focus electrode 7 and the incident side of the fourth focus electrode 8, as shown in FIGS. 2 and 3. The through hole 7b and the transverse electron beam through hole 8a are formed on the same plane, respectively, on the exit side of the fourth focus electrode 8 and the incident side of the fifth focus electrode 9 of the focus electrodes. An elongated electron beam through hole 8b and another electron beam through hole 9a for forming the second quadrupole lens are formed on the same plane, respectively.

On the other hand, when looking at the voltage applied to each of the electrodes, a first constant voltage (V1) is applied to the control electrode 3, the screen electrode 4 and the second focus electrode 6 is higher than the first constant voltage The second constant voltage V2 is applied. A focus voltage VF higher than the second constant voltage is applied to the first focus electrode 5 and the fourth focus electrode 8, and the focus voltage VF is applied to the third and fifth focus electrodes 7 and 9. A parabola type dynamic focus voltage VFd that is equal to or higher than the deflection signal is applied, and a high-voltage enowood voltage VE is applied to the final acceleration electrode 10. (V1 <V2 <VF≤VFd <VE)

As can be seen in FIGS. 2 and 3, the electron beam through holes formed in each focus electrode are formed on the same plane. Thus, the distances between corresponding electron beam through holes formed in different focus electrodes are all the same. For example, the distance between each electron beam through hole of the third focus electrode 7 and the corresponding electron beam through hole of the fourth focus electrode 8 are all set equal.

On the other hand, US Patent No. 4,814,670 also discloses an electron gun having a quadrupole lens as described above, wherein the electron beam passing holes of each electrode are formed on the same plane of each electrode, and in particular, of the electrode constituting the quadrupole lens Since the electron beam through holes are also formed on the same plane, the distance between the corresponding electron beam through holes in the adjacent electrodes is set equal.

As described above, by setting the electron beam passing holes of the electrodes constituting the quadrupole lens on the same plane, setting the distance to the corresponding electron beam passing holes of the neighboring electrodes the same, At the left and right ends, the magnitude of the parabolic type dynamic focus voltage VFd is different. This difference tends to become larger as the size of the screen becomes larger. That is, as shown in FIG. 4, the parabola-type voltage for the electron beam of blue (R) is greater than the electron beam for the electron beam of red (R) at the left end of the effective screen, while the opposite is opposite at the right end. Can be. This is because the deflection force demand of the electron beam due to the deflection yoke for deflecting the electron beam is different from the left and right sides due to the characteristics of the in-line electron gun, and there is a problem in that the focus characteristic of the electron beam is deteriorated due to the difference in parabolic voltage. In order to improve this, the voltage of the actually required waveform must be applied. However, the current general electron gun structure has a limitation in applying symmetrical waveforms to the left and right sides of the green electron beam through-hole. This causes the difference between the waveforms of the red and blue electron beams required by the CRT to appear unbalanced on the left and right sides, resulting in deterioration of the focus quality around it.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electron gun for a color cathode ray tube with improved focus characteristics at the periphery of the screen, and a color cathode ray tube having the same.

Another object of the present invention is to provide an electron gun for a color cathode ray tube, and a color cathode ray tube having the same, in which a difference in parabolic voltage for each electron beam at the screen periphery can be minimized.

1 is a side view showing an electron gun for a conventional color cathode ray tube;

2 and 3 is an exploded perspective view showing the shape of the electrode and the electron beam through-hole forming the quadrupole lens shown in FIG.

4 is a schematic graph of the distribution of parabolic voltages for red, green, and blue electron beams on the screen side of a color cathode ray tube with a conventional electron gun.

5 is a side view showing an electron gun for a color cathode ray tube according to the present invention;

6 and 7 are schematic exploded perspective views of electrode members provided in FIG. 5.

FIG. 8 is a schematic exploded perspective view of another example of electrode members that may be provided in FIG. 5; FIG.

9 is a schematic perspective view of a color cathode ray tube according to the present invention;

10 is a graph of the distribution of parabolic voltages for red, green and blue electron beams in the screen of a color cathode ray tube according to the present invention.

<Brief Description of Major Codes in Drawings>

21. cathode 22. control electrode

23. Screen electrode 24. First focus electrode

25. Second Focus Electrode 26. Third Focus Electrode

27. Fourth focus electrode 28. Fifth focus electrode

29. Final Acceleration Electrode

In order to achieve the above object, according to the present invention, the cathode, the control electrode and the screen electrode constituting the pre-triode part, and the first to third focus electrodes respectively formed between the first and second quadrupole lenses And a final accelerating electrode formed adjacent to the third focus electrode to form the main lens with the third focus electrode, wherein the electrode of any one of the focus electrodes constituting the quadrupole lens; The electron beam passing holes of red, green, and blue formed in the electrodes are formed in different planes of the electrode member, so that the distances to the corresponding red, green, and blue electron beam passing holes of neighboring electrodes are set differently. An electron gun for a color cathode ray tube is provided.

According to another feature of the invention, the first focus electrode is formed with a flat electrode member, the second focus electrode is provided with a cup-shaped electrode member adjacent to the flat electrode member, the second On the cup-shaped electrode member of the focus electrode, each electron beam through hole is formed on a different plane.

According to another feature of the invention, the second focus electrode is formed with a cup-shaped electrode member, the third focus electrode is made with a flat electrode member adjacent to the cup-shaped electrode member of the second focus electrode In the cup-shaped electrode member of the second focus electrode, the respective electron beam passing holes are formed on different planes.

According to another feature of the invention, the mutually neighboring electrodes of the first to third focus electrodes are formed of a cup-shaped electrode member, and the electron beam through holes of the cup-shaped electrode members are formed in different planes.

According to another feature of the invention, the distance between the electron beam through holes of the neighboring electrode members is increased in the order of the red electron beam through hole, the green electron beam through hole, and the blue electron beam through hole.

According to another feature of the present invention, a dynamic focus voltage synchronized with a deflection signal is applied to the first and third focus electrodes, and a constant voltage lower than the dynamic focus voltage is applied to the second focus electrode.

According to another feature of the present invention, the cup-shaped electrode member is manufactured by welding each electrode portion in a separated state in which one electron beam through hole is formed.

In addition, according to the present invention, an outer container consisting of a panel having a fluorescent film formed on the inner surface, and a funnel sealed to the panel and having a neck portion; First to third focus electrodes each having a cathode, a control electrode and a screen electrode, and first and second quadrupole lenses disposed therebetween, and adjacent to the third focus electrode, wherein the first and third focus electrodes A red, green, and blue electron beam passing holes formed in any one of the focus electrodes forming the quadrupole lens are formed in different planes of the electrode member. An electron gun for a color cathode ray tube, wherein distances of corresponding red, green, and blue electron beam passing holes are set differently; And a deflection yoke disposed in the cone portion of the funnel over the neck portion and deflecting the electron beam emitted from the electron gun to each fluorescent position of the fluorescent film.

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

5 shows the overall structure of the electron gun for color cathode ray tube according to the present invention. The overall structure of the electron gun for color cathode ray tube according to the present invention is similar to that shown in FIG.

Referring to the drawings, the electron gun comprises the cathode 21, the control electrode 22, and the screen electrode 23 forming the pre-triode, and the first, second, third and fourth forming the auxiliary lens and the first and second quadrupole lenses. And a fifth focusing electrode 24, 25, 26, 27, 28 and adjacent to the fifth focusing electrode 28 to form a main lens including a focus lens and a convergence lens. The final accelerating electrode 29 is provided. Each of the electrodes has an electron beam through hole in which three electron beams pass through, or three electron beams pass through, in line.

Meanwhile, the third focus electrode 26 is formed of two electrode members 26a and 26b in which cup and plate electrode members are sequentially arranged, and the fourth focus electrode 27 also includes two cup electrode members 27a, 27b), and the fifth focus electrode 28 is formed of three electrode members 28a, 28b, and 28c so as to have a shape in which an internal electrode is installed inside the plate and cup.

In addition, a predetermined voltage is applied to each of the electrodes. A first constant voltage V1 is applied to the control electrode 22, and a higher than the first constant voltage is applied to the screen electrode 23 and the second focus electrode 25. The second constant voltage V2 is applied. A focus voltage VF higher than the second constant voltage is applied to the first and fourth focus electrodes 24 and 27, and the focus voltage VF is applied to the third and fifth focus electrodes 26 and 28. A parabola type dynamic focus voltage VFd that is equal to or higher than the deflection signal is applied, and a high voltage enowood voltage VE is applied to the final acceleration electrode. (V1 <V2 <VF≤VFd <VE)

The application of the voltage to each of the electrodes is not limited to the above embodiment, and any configuration can be used as long as the electron beam can be focused by forming at least two quadrupole lenses.

In the dynamic focus electron gun for the color cathode ray tube according to the present invention configured as described above, the first quadrupole lens is disposed between the electrode member 26b of the third focus electrode 26 and the electrode member 27a of the fourth focus electrode 27. And a second quadrupole lens is formed between the electrode member 27b of the fourth focus electrode 27 and the electrode member 28b of the fifth focus electrode 28. The third and fifth focus electrodes 26 and 28 are electrodes to which a dynamic focus voltage is applied, and the fourth electrode 27 corresponds to an electrode to which the focus electrode is applied.

According to a feature of the invention, the distance between the electron beam through holes formed in the electrodes constituting the quadrupole lens is formed differently for each of the electron beam through holes of red, green, and blue. For example, the first quadrupole lens is formed between the electrode member 26b of the third focus electrode 26 and the electrode member 27a of the fourth focus electrode 27, wherein red, green, and blue The distance between the electron beam passing holes is differently formed. In addition, the second quadrupole lens is formed between the other electrode member 27b of the fourth focus electrode 27 and the electrode member 28a of the fifth focus electrode 28, similarly passing through the red, green, and blue electron beams. Differently form the distance between the balls. The method of forming the distances of the electron beam passing holes differently may be implemented in various forms. The easiest method is to form the stepped surface of the cup-shaped electrode constituting the quadrupole lens.

6 and 7 are schematic perspective views illustrating some of the electrodes that may be provided in the electron gun of FIG. 5.

Referring to FIG. 6, the plate-shaped electrode member 26b of the third focus electrode has red, green, and blue electron beam through holes 71R, 71G, and 71B formed in an elongated shape, and the cup type of the fourth focus electrode. In the electrode member 27a, red, green, and blue electron beam through holes 72R, 72G, and 72B formed in a horizontal shape are formed. In order to form different distances between the electron beam passing holes for each electron beam passing hole, a step as shown in the cup-shaped electrode member 27a of the fourth focus electrode is formed. That is, three planes having different heights are provided on the surface where the electron beam passing holes are formed on the cup-shaped electrode member 27a to form respective electron beam passing holes on the three different planes. By this step, the respective electron beam passing holes are arranged on different planes from each other.

When the electrode member 26b and the electrode member 27a are assembled, the distance between the red electron beam through hole 71R of the electrode member 26b and the red electron beam through hole 72R of the electrode member 27a is relatively relative to each other. It will be arranged with the shortest distance. On the contrary, the distance between the blue electron beam passing hole 71B of the electrode member 26b and the blue electron beam passing hole 72B of the electrode member 27a will be arranged as the distance that extends with respect to each other relatively. On the other hand, the distance between the green electron beam through hole 71G and the green electron beam through hole 72G is disposed as an intermediate distance.

Meanwhile, referring to FIG. 7, red, green, and blue electron beam through holes 73R, 73G, and 73B are formed in the cup-shaped electrode member 27b of the fourth focus electrode, and the fifth focus electrode is formed. The plate-shaped electrode member 28a has red, green, and blue electron beam through holes 74R, 74G, and 74B formed in a horizontal shape. In order to form different distances between the electron beam passing holes for each electron beam passing hole, a step as shown in the cup-shaped electrode member 27b of the fourth focus electrode is formed. As described above, the respective electron beam passing holes are arranged on different planes from each other.

When the electrode member 27b and the electrode member 28a are assembled, the distance between the red electron beam through hole 73R of the electrode member 27b and the red electron beam through hole 74R of the electrode member 28a is relatively relative to each other. It will be arranged with the shortest distance. On the contrary, the distance between the blue electron beam through hole 73B of the electrode member 27b and the blue electron beam through hole 74B of the electrode member 28a will be disposed as the distance that extends with respect to each other relatively. On the other hand, the green electron beam through hole 73G and the green electron beam through hole 74G are arranged at an intermediate distance.

The electrode members described with reference to FIGS. 6 and 7 above may both be provided in the electron gun, or only one of them may be provided in the electron gun. That is, both the first quadrupole lens and the second quadrupole lens may be made of electrode members having different electron beam forming surfaces, or only one lens may be made of electrode members having different electron beam forming surfaces. In addition, although the electron beam through holes formed in the electrode members are illustrated in the vertical or horizontal shape, the shape of the electron beam through holes is not limited thereto and may be other shapes. For example, it may be formed into a circle, an oval, a rectangle, or a polygon.

In the example described with reference to FIGS. 5 to 7, only an example in which the electron beam through hole forming surface of the cup-shaped electrode member forming the quadrupole lens is stepped is formed, which is manufactured integrally using conventional mold technology. . That is, by using a mold having a predetermined shape, it can be produced in the required shape having different planes of electron beam through hole formation through various operations such as pressing and punching.

8 is a schematic separated perspective view of another example of an electrode member that may be provided in the electron gun according to the present invention.

Referring to the drawings, the electrode member 27a may be of a separate type, and may be assembled into electrode members as shown in FIG. 6 by mutual welding. The red, green, and blue electron beam through holes 85R, 85G, 85B formed in each of the electrode portions 81, 82, 83 will be placed on different planes when the electrode portions 81, 82, 83 are mutually assembled. will be.

In another example, a flat electrode may not be used, and neighboring electrodes may be provided as cup electrodes. For example, the same effect can be expected when the flat electrode 26b of FIG. 6 is replaced with the cup-shaped electrode 27b of FIG. On the contrary, the same applies to the case where the plate-shaped electrode 28a of FIG. 7 is replaced with the cup-shaped electrode 27a of FIG. 6.

Shown in FIG. 9 is a schematic partial cutaway perspective view of a color cathode ray tube equipped with an electron gun as described above.

Referring to the drawings, the color cathode ray tube 50 is a panel 51 formed on the inner surface of the fluorescent film 51a formed of a red or blue green phosphor formed in a dot or stripe pattern, and the panel 51 is sealed to the panel 51. A funnel 52 having a neck portion 52a and a cone portion 52b, an electron gun 60 mounted on the neck portion 52a to excite the fluorescent film 51a, and the funnel 52 And a deflection yoke 53 mounted over the neck portion 52a and the cone portion 52b.

Hereinafter, the operation of the electron gun for color cathode ray tube according to the present invention will be described.

Electrodes provided in the electron gun shown in FIG. 5 and constituting the quadrupole lens can be interpreted as a kind of capacitance. The capacitance is inversely proportional to the distance between the electrodes, which decreases as the distance between the electrodes increases, so that the capacitance between red electron beam through holes (ie, between 71R and 72R and between 73R and 74R) is the blue electron beam through hole. Is greater than the capacitance between them (i.e., between 71B and 72B and between 73B and 74B). In addition, when the capacitance increases between the electron beam through holes forming the quadrupole lens, the voltage between them decreases, so that the voltage between the through holes of the red electron beam becomes smaller than the voltage applied between the through holes of the blue electron beam. That is, when the same parabolic voltage (VFd) and the focus voltage (VF) are applied to each electrode forming the quadrupole lens, the difference in the parabolic voltage occurring at the left and right ends of the screen is measured by the electrodes as described above. This can be compensated by the difference in capacitance between them.

That is, as described with reference to FIG. 4, the phenomenon in which the parabola voltage for the red electron beam at the right end of the screen is greater than the parabola voltage for the blue electron beam is shown in FIGS. 6 to 8. By forming as described above, the parabolic voltage for the electron beam of blue becomes larger than the parabola voltage for the electron beam of red, so that the parabolic voltage for the blue electron beam can be formed symmetrically as shown in FIG. 10.

In the electron gun for color cathode ray tube according to the present invention, parabolic voltages are symmetrically formed at the left and right ends of the screen by differently forming heights of planes on which the electron beam passing holes are formed on the electrode member forming the quadrupole lens. Therefore, the focus quality may be improved at the periphery of the screen.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, these are only examples, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the present invention should only be limited by the appended claims.

Claims (8)

A cathode, a control electrode, a screen electrode, a first to third focus electrode each having first and second quadrupole lenses forming therebetween, and adjacent to the third focus electrode; In the electron gun for a color cathode ray tube comprising a final acceleration electrode constituting the third focus electrode and the main lens, The red, green, and blue electron beam passing holes formed in one of the focus electrodes constituting the quadrupole lens are formed in different planes of the electrode member, so that the corresponding red, green, and blue electron beams of neighboring electrodes are formed. Electron gun for color cathode ray tube, characterized in that the distance to the through hole is set differently. The method of claim 1, The first focus electrode includes a plate electrode member, and the second focus electrode includes a cup electrode member adjacent to the plate electrode member, and each of the second focus electrodes on a cup electrode member. An electron gun for a color cathode ray tube, wherein the electron beam passing holes are formed on different planes. The method of claim 1, The second focus electrode includes a cup type electrode member, and the third focus electrode includes a plate type electrode member adjacent to the cup type electrode member of the second focus electrode, and the cup type of the second focus electrode. An electron gun for a color cathode ray tube, wherein the electron beam passing holes in the electrode member are formed on different planes. The method of claim 1, The neighboring electrodes of the first to third focus electrodes are formed of a cup-shaped electrode member, and the electron beam passing holes of the cup-shaped electrode members are formed in different planes. The method according to any one of claims 2 to 4, And the distance between the electron beam passing holes of the neighboring electrode members is increased in the order of the red electron beam passing hole, the green electron beam passing hole, and the blue electron beam passing hole. The method according to any one of claims 2 to 4, And a dynamic focus voltage synchronized with a deflection signal is applied to the first and third focus electrodes, and a constant voltage lower than the dynamic focus voltage is applied to the second focus electrode. The method according to any one of claims 2 to 4, The cup-shaped electrode member is an electron gun for a color cathode ray tube, characterized in that the manufacturing by welding each of the electrode portion of the separated state in which one electron beam through-hole is formed. An outer container comprising a panel having a fluorescent film formed on an inner surface thereof, and a funnel sealing the panel and having a neck portion; First to third focus electrodes each having a cathode, a control electrode and a screen electrode, and first and second quadrupole lenses disposed therebetween, and adjacent to the third focus electrode, wherein the first and third focus electrodes The red, green, and blue electron beam through holes formed in one of the focus electrodes forming the quadrupole lens are formed in different planes of the electrode member. An electron gun for a color cathode ray tube in which distances to corresponding electron beam passing holes of red, green, and blue are set differently; And a deflection yoke disposed in the cone portion of the funnel over the neck portion and deflecting the electron beam emitted from the electron gun to each fluorescent position of the fluorescent film.