KR101044410B1 - Cathode ray tube - Google Patents

Abstract

The present invention relates to a cathode ray tube including an electron gun in which the resolution of the cathode ray tube electron gun structure is effectively improved.

The cathode ray tube according to the present invention has a panel having a phosphor screen formed on its inner surface, a funnel coupled to the panel, an electron gun from which an electron beam is emitted, a deflection yoke for deflecting the electron beam in horizontal and vertical directions, and color screening. A cathode ray tube including a shadow mask, wherein the electron gun comprises: a tripole portion for generating an electron beam, a prefocus lens for preliminarily focusing and accelerating the electron beam generated at the tripole portion, and focusing through the prefocus lens. And a main lens for finally focusing and accelerating the accelerated electron beam, and among the electrodes forming the triode, an electron beam through hole of a control electrode is formed in a horizontal shape, and an electron beam through hole of an acceleration electrode is formed in an elongated shape. Among the electrodes forming the focus lens, the first prefocus electrode is formed in a form in which two plate electrodes are combined. Group first free focus electron beam passage hole in the electrode opposing the accelerating electrode in the electrode is formed in a longitudinal elongate second focus electrode-free electron beam passage hole in the electrode opposing the is characterized in that formed in a circular shape.

Cathode ray tube, electron gun

Description

Cathode Ray Tube {CATHODE RAY TUBE}

1 is a view for explaining a conventional cathode ray tube structure.

2 is a view for explaining the structure of a conventional electron gun.

3 is a view for explaining the shape of the anode viewed in the direction D of FIG.

4 is a view illustrating a shape of the main focusing electrode viewed in the C direction.

5 is a diagram illustrating a magnetic field distribution of a self-focusing deflection yoke.

6 is a view for explaining a control electrode of a conventional electron gun.

7 is a view for explaining an acceleration electrode of a conventional electron gun.

8 is a diagram illustrating a first prefocus electrode of a conventional electron gun.

9 is a view for explaining a second prefocus electrode of a conventional electron gun.

10 and 11 illustrate electron beam spots on a screen when high and low currents are applied.

12 and 13 illustrate spots formed on a screen when a divergence angle of an electron beam is reduced in a conventional electron gun.

14 is a view for explaining the cathode ray tube structure of the present invention.

Fig. 15 is a diagram for explaining the structure of an electron gun of the present invention.

Fig. 16 is a diagram explaining a control electrode of an electron gun of the present invention.                 

Fig. 17 is a diagram explaining an acceleration electrode of the electron gun of the present invention.

FIG. 18 is a diagram for explaining a first prefocus electrode facing the acceleration electrode. FIG.

19 is a diagram illustrating a first prefocus electrode facing the second prefocus electrode.

20 is a diagram for explaining a second prefocus electrode.

21 and 22 illustrate electron beam spots on a screen when high and low currents are applied in the present invention.

Description of the Related Art

31; Panel 32; Funnel

33; Shadow mask 34; Mask frame

35; Mask spring 36; Stud pins

37; Inner shield 38; Electron gun

39; Deflection yoke 40; CPM

41; Phosphor screen 42; Reinforcement band

50; Heater 51; cathode

52; Control electrode 53; Acceleration Electrode

54; A first prefocus electrode 55; Second prefocus electrode

56; Focusing electrode 57; anode

The present invention relates to a cathode ray tube, and more particularly, to a cathode ray tube including an electron gun in which the resolution of the cathode ray tube electron gun structure is effectively improved.

1 is a view for explaining a conventional cathode ray tube structure.

Referring to FIG. 1, the conventional cathode ray tube is a panel 1, which is a front glass, and a funnel 2, which is a panel and a rear glass, are coupled to each other to form a vacuum tube. A phosphor screen 11 is formed on the inner surface of the panel 1, and an electron gun 8 is installed on the funnel 2 facing the phosphor screen 11.

In addition, a shadow mask 3 spaced apart from the phosphor screen 11 at predetermined intervals to perform color screening of the electron beam is installed, and the shadow mask 3 is coupled to the mask frame 4.

The mask frame 4 is welded to the mask spring 5 and coupled thereto, and the mask spring 5 is supported on the panel 1 by engaging the stud pin 6.

In addition, the mask frame 4 is combined with an inner shield 7 made of a magnetic material to reduce the movement of the electron beam by an external magnetic field, thereby reducing the influence of the geomagnetic field behind the cathode ray tube.

On the other hand, a neck of the funnel 2 is provided with a convergence purity correction magnet (CPM) 10 for adjusting the R, G, B electron beams so that the electron beam emitted from the electron gun 8 converges at one point. A deflection yoke 9 is provided for deflection of the electron beam.                         

In addition, the reinforcing band 12 is installed to strengthen the front glass according to the vacuum state inside.

Referring to the operation of the cathode ray tube configured as described above, the electron beam emitted from the electron gun 8 is deflected in the vertical and horizontal directions by the deflection yoke 9, and the deflected electron beam is directed to the beam passing hole of the shadow mask 3. By passing through and hitting the phosphor screen 11 on the front, a desired image is displayed.

2 is a view for explaining the structure of a conventional electron gun.

Referring to FIG. 2, the conventional electron gun 8 is largely divided into a tripolar portion and a main lens, and a prefocus lens between the tripolar portion and the main lens.

The three-pole portion includes a cathode 21 in which the heater 20 is embedded and arranged inline, and a control electrode 22 and an acceleration electrode 23 to control and accelerate electrons emitted from the cathode 21.

The main lens includes a main focusing electrode 26 and an anode 27 for focusing and finally accelerating the electron beam generated at the triode. The main focusing electrode 26 forming the main lens includes a cap electrode 261 and a electrostatic field control electrode body 262 provided with a rim having a race track shape. 27 is composed of a cup (CUP) electrode 271 and a electrostatic field control electrode body 272 with a rim in the form of a race track (RACE TRACK). In this case, the electrostatic field control electrode bodies 262 and 272 are made to have the same focusing force of the three electron beams, and are formed in a shape retracted from the cap electrode 261 or the cup electrode 271 in a predetermined direction. 3 is a view of the anode 27 in the D direction, and FIG. 4 is a view of the main focusing electrode 26 in the C direction.

The prefocus lens includes a first prefocus electrode 24 and a plate-shaped second prefocus electrode 25.

Here, the control electrode 22 is grounded, a voltage of 500 to 1000 V is applied to the acceleration electrode 23, a high voltage of 25 to 35 KV is applied to the anode electrode 27, and the main focusing electrode 26 is applied. ), An intermediate voltage of 20-30% of the voltage applied to the anode 27 is applied.

In the electron gun 8 configured as described above, as a predetermined voltage is applied to each electrode, the electron beam generated at the triode is focused and accelerated to strike the phosphor screen 11.

In general, since the red, green, and blue electron beams are arranged horizontally in the cathode ray tube using the inline electron gun 8, a self-convergence type deflection yoke 9 for converging three electron beams in one place. Is used.

As shown in FIG. 5, the self-focusing yoke 9 has a distribution of magnetic fields, and the horizontal deflection magnetic field HB is a pin cushion (PIN-CUSHION) type, and the vertical deflection magnetic field VB is a barrel. The mold prevents misconvergence in the phosphor screen 11.

The magnetic field can be described by dividing into two-pole and four-pole components, the two-pole component to deflect the electron beam in the horizontal and vertical direction, the four-pole component to focus the electron beam in the vertical direction and diverge in the horizontal direction As a result, astigmatism is generated to deteriorate the shape of the spot of the electron beam.                         

6 is a view for explaining a control electrode of a conventional electron gun.

Referring to FIG. 6, the electron beam through hole 221 of the control electrode 22 has a circular or square shape and has a diameter of about 0.5 mm to 0.7 mm. The electrode thickness around the electron beam through hole 221 is formed to be 0.08 mm to 0.1 mm.

In addition, the accelerating electrode 23 illustrated in FIG. 7 has a slot 232 formed around the electron beam through hole 231, which is formed on a surface of the acceleration electrode 23 facing the first prefocus electrode 24. The electron beam through hole 231 is formed in a circular or square shape. The acceleration electrode 23 has a thickness of about 0.37 mm, and the depth of the slot 232 is about 0.15 mm, and the depth of the slot 232 is about 40% of the entire thickness of the acceleration electrode 23. The slot 232 has a horizontal size larger than the vertical size, and the horizontal slot 232 acts to reduce the haze phenomenon at the periphery of the screen.

8 illustrates the first prefocus electrode 24, and the electron beam through hole 241 of the first prefocus electrode 24 has a diameter of about 0.9 mm to about 1.5 mm.

FIG. 9 illustrates a second prefocus electrode 25. The second prefocus electrode 25 is formed in a plate shape, and the electron beam passage hole 251 has a diameter of about 3.0 mm to 4.0 mm. The second prefocus electrode 25 may be formed of an electrode having a cap shape or an electrode having a cup CUP shape. Since the voltage applied to the second prefocus electrode 25 is low, a prefocus lens is formed around the second prefocus electrode 25.

On the other hand, the conventional electron gun configured as described above has a screen spot as shown in FIG. 10 when a high current is applied, and has a screen spot as shown in FIG. 11 when a low current is applied.

First, the spot formed at the center of the screen when the high current is applied is formed larger than the spot formed at the center of the screen when the low current is applied, so that the resolution according to the amount of current is not constant.

And, as shown in FIG. 11, when a low current is applied, a halo phenomenon occurs in the periphery of the screen, so that the resolution of the periphery of the screen is very deteriorated.

In order to solve the above problems, the divergence angle of the electron beam is reduced by reducing the pore diameter (radius of the electron beam passing hole) of the control electrode 22, the acceleration electrode 23, and the first prefocus electrode 24 or the spacing between the electrodes. A method of evenly improving the size of spots formed in the center and periphery of the screen by reducing α) has been proposed.

In general, factors affecting the spot size of the electron beam formed on the phosphor screen 11 among the design characteristics of the electron gun 8 include lens magnification, spatial charge repulsion force, and spherical aberration of the main lens. The influence of the spot size (Dx) due to the magnification is that the basic voltage condition, focal length, and the length of the electron gun are determined, so there are few parts that can be used as a design element in the electron gun, and the effect is minimal.

On the other hand, the influence of the spot size (Dic) due to the spherical aberration characteristics of the main lens refers to the expansion of the spot diameter due to the difference in focal length between the electrons passing through the paraxial axis of the lens and the electrons passing through the circular axis. In contrast, if the divergence angle at which the electron beam is incident to the main lens is small, a smaller spot size may be realized in the phosphor screen 11.

Therefore, it was intended to reduce the spot size of the screen by reducing the divergence angle of the electron beam.

12 and 13 are diagrams illustrating spots formed on the screen when the divergence angle of the electron beam is reduced in the conventional electron gun.

As shown in FIGS. 12 and 13, when the divergence angle of the electron beam is reduced, the electron beam spot size at the center of the screen becomes small when high current is applied.

However, when a low current is applied, the electron beam is strongly concentrated in the vertical direction by the deflection magnetic field of the deflection yoke, so that the electron beam spot size at the center of the screen is rather enlarged. In addition, the electron beam spot size of the screen periphery is considerably reduced. There is a problem in that an interference fringe is generated on the screen due to a correlation between the spot size of the reduced electron beam and the vertical width Pv of the electron beam through-hole of the shadow mask.

In general, such an interference fringe is called a moire, which acts as a factor that hinders the resolution of the screen.

In order to remove the moiré phenomenon as described above, a redesign of the shadow mask is required, such as shrinking the electron beam through hole of the shadow mask, but there is a problem that excessive development cost requires a period.

It is an object of the present invention to provide a cathode ray tube in which the resolution can be effectively improved by appropriately adjusting the shape and size of the electron beam passing hole of the electron gun.

The cathode ray tube according to the present invention has a panel having a phosphor screen formed on its inner surface, a funnel coupled to the panel, an electron gun from which an electron beam is emitted, a deflection yoke for deflecting the electron beam in horizontal and vertical directions, and color screening. A cathode ray tube including a shadow mask, wherein the electron gun comprises: a tripole portion for generating an electron beam, a prefocus lens for preliminarily focusing and accelerating the electron beam generated at the tripole portion, and focusing through the prefocus lens. And a main lens for finally focusing and accelerating the accelerated electron beam, and among the electrodes forming the triode, an electron beam through hole of a control electrode is formed in a horizontal shape, and an electron beam through hole of an acceleration electrode is formed in an elongated shape. Among the electrodes forming the focus lens, the first prefocus electrode is formed in a form in which two plate electrodes are combined. Group first free focus electron beam passage hole in the electrode opposing the accelerating electrode in the electrode is formed in a longitudinal elongate second focus electrode-free electron beam passage hole in the electrode opposing the is characterized in that formed in a circular shape.

More preferably, the horizontal size X1 and the vertical size Y1 of the electron beam passing hole of the control electrode satisfy a relationship of 1.1 ≦ X1 / Y1 ≦ 1.8.

More preferably, the electron beam through hole formed in the control electrode is characterized in that the rectangular shape.

More preferably, the horizontal size (X2) and the vertical size (Y2) of the electron beam through hole of the acceleration electrode satisfies the relationship of 0.6≤X2 / Y2≤0.9.

More preferably, the electron beam through hole formed in the acceleration electrode is characterized in that the rectangular shape.

More preferably, the horizontal size X3 and the vertical size Y3 of the electron beam passing hole of the acceleration electrode counter electrode of the first prefocus electrode satisfy a relationship of 0.2 ≦ X3 / Y3 ≦ 0.9.

More preferably, the electron beam through hole of the acceleration electrode counter electrode of the first prefocus electrode is characterized in that the rectangular shape.

More preferably, the electron beam through hole of the second prefocus electrode among the electrodes forming the prefocus lens has a circular shape having a larger radius than the electron beam through hole of the electrode facing the second prefocus electrode among the first prefocus electrodes. It is characterized by that.

Hereinafter, a cathode ray tube according to the present invention will be described in detail with reference to the accompanying drawings.

It is a figure explaining the cathode ray tube structure of this invention.

Referring to FIG. 14, the cathode ray tube according to the present invention is coupled to a panel 31 which is a front glass, and a panel 31 and a funnel 32 which is a rear glass so that the inside thereof is maintained in a vacuum state and a vacuum tube is formed. Achieve. A phosphor screen 41 is formed on an inner surface of the panel 31, and an electron gun 38 is installed on the funnel 32 facing the phosphor screen 41.

In addition, a shadow mask 33 spaced apart from the phosphor screen 41 at predetermined intervals to perform color screening of the electron beam is installed, and the shadow mask 33 is coupled to the mask frame 34.

The mask frame 34 is welded to the mask spring 35 and coupled to the mask spring 35, and the mask spring 35 is supported on the panel 31 by engaging the stud pin 36.

In addition, the mask frame 34 is combined with an inner shield 37 made of a magnetic material to reduce the movement of the electron beam by an external magnetic field, thereby reducing the influence of the geomagnetic field behind the cathode ray tube.

On the other hand, the neck portion of the funnel 32 is provided with a convergence purity correction magnet (CPM) 40 for adjusting the R, G, B electron beams so that the electron beam emitted from the electron gun 38 converges at one point. A deflection yoke 39 is provided for deflection of the electron beam.

In addition, the reinforcing band 42 is installed to strengthen the front glass according to the vacuum state inside.

Referring to the operation of the cathode ray tube configured as described above, the electron beam emitted from the electron gun 38 is deflected in the vertical and horizontal directions by the deflection yoke 39, and the deflected electron beam passes through the beam passing hole of the shadow mask 33. By passing through and hitting the phosphor screen 41 on the front surface, a desired image is displayed.

It is a figure explaining the structure of the electron gun of this invention.

Referring to FIG. 15, the electron gun 38 of the present invention is largely divided into a tripole portion and a main lens, and a prefocus lens between the tripole portion and the main lens.

The three-pole portion includes a cathode 51 having a heater 50 embedded therein and arranged in-line, and a control electrode 52 and an acceleration electrode 53 for controlling and accelerating electrons emitted from the cathode 51. .

The main lens includes a main focusing electrode 56 and an anode 57 for focusing and finally accelerating the electron beam generated in the triode. The main focusing electrode 56 forming the main lens includes a cap electrode 561 having a rim having a race track shape, and an electrostatic field control electrode body 562. 57 is composed of a cup (UP) electrode 571 and a electrostatic field control electrode body 572 provided with a rim in the form of a race track (RACE TRACK). The electrostatic field control electrode bodies 562 and 572 are configured to equalize the focusing force of the three electron beams, and are formed in a shape in which the cap electrode 561 or the cup electrode 571 is retracted in a predetermined direction.

The prefocus lens includes a first prefocus electrode 54 and a plate-shaped second prefocus electrode 55.

Here, the control electrode 52 is grounded, a voltage of 500 to 1000 V is applied to the acceleration electrode 53, a high voltage of 25 to 35 KV is applied to the anode electrode 57, and the main focusing electrode 56 is applied. ), An intermediate voltage of 20 to 30% of the voltage applied to the anode 57 is applied.

In the electron gun 38 configured as described above, as a predetermined voltage is applied to each electrode, the electron beam generated at the triode is focused and accelerated to strike the phosphor screen 41.

Fig. 16 is a view for explaining the control electrode of the electron gun of the present invention.

Referring to FIG. 16, the electron beam through hole 521 of the control electrode 52 is formed in a horizontal shape. The electron beam through hole 521 of the control electrode 52 has a substantially rectangular shape, and the horizontal size X1 and the vertical size Y1 have a relationship of 1.1 ≦ X1 / Y1 ≦ 1.8.

In addition, the accelerating electrode 53 illustrated in FIG. 17 has a slot 532 formed around the electron beam through hole 531, and the slot 532 is formed on a surface opposite to the first prefocus electrode 54. The electron beam through hole 531 is formed in the shape of an elongate shape.

The electron beam through hole 531 of the acceleration electrode 53 has a substantially rectangular shape, and the horizontal size X2 and the vertical size Y2 have a relationship of 0.6 ≦ X2 / Y2 ≦ 0.9.

FIG. 18 illustrates a first prefocus electrode 541 facing the acceleration electrode 53, and FIG. 19 illustrates a first prefocus electrode 542 facing the second prefocus electrode 55. .

As shown in FIG. 18 and FIG. 19, the first prefocus electrode 54 is formed by joining two plate electrodes, and the electron beam of the first prefocus electrode 541 facing the acceleration electrode 53 is formed. The through hole 5411 is formed in a substantially rectangular shape, and the horizontal size X3 and the vertical size Y3 have a relationship of 0.2 ≦ X3 / Y3 ≦ 0.9.

The electron beam through hole 5251 of the first prefocus electrode 542 facing the second prefocus electrode 55 is formed in a circular shape similar to a horizontal size and a vertical size.

20 illustrates the second prefocus electrode 55, wherein the second prefocus electrode 55 is formed in a plate shape, and the electron beam through hole 551 is the electron beam through hole of the first prefocus electrode 542. It has a circular shape larger than the radius of 5221.

On the other hand, the electron gun of the present invention configured as described above has a screen spot as shown in FIG. 21 when high current is applied, and has a screen spot as shown in FIG. 22 when low current is applied.

First, a spot formed at the center of the screen when high current is applied is formed to a size similar to a spot formed at the center of the screen when low current is applied.

In addition, as shown in FIG. 22, the spot formed at the center of the screen when the low current is applied is formed in a small size unlike the spot shown in FIG. 13, and the spot formed at the periphery of the screen is somewhat larger than the spot shown in FIG. 13. Is formed.

Weak halo phenomenon occurs at the periphery of the screen when low current is applied, but it does not affect the resolution and removes the interference pattern on the screen by the relationship between the spot size of the electron beam and the vertical width (Pv) of the electron beam through-hole of the shadow mask. can do.

As such, the present invention provides a method for evenly improving the size of spots formed in the center and periphery of the screen.

The present invention can improve the resolution of the cathode ray tube by appropriately adjusting the electron beam through hole formed in the electrode of the electron gun to improve the size of the spot formed on the screen evenly in the center and periphery of the screen.

Claims (8)

Cathode rays including a panel having a phosphor screen formed on an inner surface thereof, a funnel coupled to the panel, an electron gun from which an electron beam is emitted, a deflection yoke for deflecting the electron beam in horizontal and vertical directions, and a shadow mask that performs color screening. In the tube, The electron gun includes a tripole portion for generating an electron beam, a prefocus lens for preliminarily focusing and accelerating the electron beam generated from the tripole portion, and a main body for finally focusing and accelerating the electron beam focused and accelerated through the prefocus lens. A lens is included, Of the electrodes forming the three-pole portion, the electron beam through hole of the control electrode is formed in the horizontal shape, the electron beam through hole of the acceleration electrode is formed in the longitudinal shape, Among the electrodes forming the prefocus lens, the first prefocus electrode is formed in the form of a combination of two plate-shaped electrodes, and the electron beam through hole of the electrode facing the acceleration electrode in the first prefocus electrode is formed in an elongated shape. A cathode ray tube, characterized in that the electron beam passing hole of the electrode facing the second prefocus electrode is formed in a circular shape. The method of claim 1, And a horizontal size (X1) and a vertical size (Y1) of the electron beam passing hole of the control electrode satisfy a relationship of 1.1 ≦ X1 / Y1 ≦ 1.8. 3. The method of claim 2, The electron beam passing hole formed in the control electrode is a cathode ray tube, characterized in that the rectangular shape. The method of claim 1, And a horizontal size (X2) and a vertical size (Y2) of the electron beam passing hole of the acceleration electrode satisfy a relationship of 0.6 ≦ X2 / Y2 ≦ 0.9. The method of claim 4, wherein Cathode ray tube, characterized in that the electron beam through hole formed in the acceleration electrode has a rectangular shape. The method of claim 1, And a horizontal size (X3) and a vertical size (Y3) of the electron beam through hole of the acceleration electrode counter electrode of the first prefocus electrode satisfy a relationship of 0.2≤X3 / Y3≤0.9. The method of claim 6, The cathode ray tube of claim 1, wherein the electron beam through hole of the counter electrode of the first prefocus electrode has a rectangular shape. The method of claim 1, The electron beam through hole of the second prefocus electrode among the electrodes forming the prefocus lens has a circular shape having a radius larger than that of the electron beam through hole of an electrode facing the second prefocus electrode among the first prefocus electrodes. Cathode ray tube.

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