KR100235998B1 - A converging electrode of electron gun for color crt - Google Patents

Abstract

The present invention relates to an electron gun used in a large color TV or a high-definition industrial water tube, and more particularly, by changing the shape of the first focusing electrode to which a fixed voltage is applied among the focusing electrodes composed of the first and second focusing electrodes. To accommodate the design variation and design limitation of the first focusing electrode designed according to the thickness change of the raw member or the design of the electron gun which constitute the focusing electrode of the electron gun, and the first focusing electrode is firmly fixed by Mandrel during the beading process. The present invention relates to a focusing electrode of an electron gun for a color cathode ray tube which reduces the error of electron gun assembly by providing a fixing means to the first focusing electrode.

According to the present invention, a first electron beam passing hole of the first focusing electrode facing the second focusing electrode is formed in a vertical shape, and an internal electrode having a third electron beam passing hole is provided inside the first focusing electrode, and a third electron beam is provided. The through hole can achieve the object by making the second electron beam through hole coincide with the central axis thereof, and having the same diameter as the second electron beam through hole.

Description

Focusing electrode of electron gun for color cathode ray tube

The present invention relates to an electron gun used in a large color TV or a high-definition industrial receiving tube, and more particularly, to change the shape of the first focusing electrode to which a fixed voltage is applied among the focusing electrodes divided into first and second focusing electrodes. To accommodate the design variation and design limitation of the first focusing electrode designed according to the thickness change of the raw member or the design change of the electron gun which constitute the focusing electrode of the electron gun, the first focusing electrode is The present invention relates to a focusing electrode of an electron gun for a color cathode ray tube, which provides a fixing means to a first focusing electrode so as to be firmly fixed to reduce an electron gun assembly error.

The electron gun is one of the components forming the water tube, and focuses three electron beams emitted from the cathode on the red, green, and blue fluorescent surface applied inside the front of the water tube to cause the phosphor to react in response to each electron beam. It is a device for forming pixels in front.

1 is a cross-sectional view showing a schematic installation of an electron gun in a general color water tube, in which the color water tube deflects the electron gun 2 and the electron beam 1 generating the electron beam 1 to all directions of the screen up, down, left, and right. It is roughly divided into the deflection yoke 3 and the water column 4 which forms a pixel in response to the electron beam 1.

A screen 5 is formed in front of the water pipe 4, and a phosphor surface 6 coated with a phosphor is formed on an inner surface thereof.

A funnel 7 is formed around the screen 5 and converges to the rear, and the converging portion is formed with a tubular neck 8 having a predetermined diameter.

An electron gun 2 is provided inside the neck portion 8 and a deflection yoke 3 is provided outside, and an electron beam 1 emitted from the electron gun 2 is disposed between the fluorescent surface 6 and the electron gun 2. A shadow mask 9 having a plurality of electron beam passing holes is fixed along the front inner circumferential surface of the funnel 7 so as to be selectively projected onto the red, green, blue fluorescent surface 6.

FIG. 2 is a cross sectional view showing a schematic structure of the color water tube electron gun, wherein the electron gun 2 is roughly divided into a triode 21 and a main lens unit 22, and the tripole 21 is an inherent heater 23a. The order of the cathode 23 which emits hot electrons according to the heat source, the control electrode 24 which controls the hot electrons emitted from the cathode 23 and the acceleration electrode 25 which accelerates the hot electrons emitted from the cathode 23. The main lens unit 22 includes a focusing electrode 26 for focusing the electron beam generated by the triode 21 and an anode electrode 27 for finally accelerating.

Here, the control electrode 24 is grounded, a low voltage of 500 to 1000 V is applied to the acceleration electrode 25, a high voltage of 25 to 35 kv is applied to the anode electrode 27, and the anode electrode voltage is applied to the focusing electrode 26. A medium voltage corresponding to 20-30% of is applied.

In the electron gun for the color cathode ray tube configured as described above, while a predetermined voltage is applied to each electrode, an equipotential surface is formed between the focusing electrode 26 and the anode electrode 27 by a potential difference due to a voltage difference, and the assembly of the equipotential surfaces is electrostatic The electron beam 1 formed at the triode 21 by acting as a lens passes through the electron beam passing hole of the shadow mask 9 after being focused by the main lens.

The electron beam 1 that has passed through the electron beam through hole of the shadow mask is focused to the center of the screen and hits the fluorescent surface 6 to form a pixel.

Concentration of the electron beam 1 at the center of the screen is finished by the electrostatic lens as described above, but in order to sequentially scan the electron beam to each area of the screen, deflection of the electron beam by the deflection yoke is required.

The following problem appears when deflecting an electron beam with the deflection yoke.

Inline electron guns commonly used in color TV receivers are arranged in the same axis as the neck (8) in a horizontal line to emit the electron beam (1) to the fluorescent surface, except for slight pincushion distortion on the fluorescent surface (6) during up and down deflection. While there is almost no deviation in concentration, the deviation of the electron beam increases in the left and right sides of the screen as shown in FIG. 3 in the place away from the deflection point during left and right deflection.

As described above, a deflection yoke composed of a vertical deflection coil of a troidal winding and a horizontal deflection coil of a saddle winding to correct the pincushion distortion in the vertical direction and the misalignment of the electron beam in the horizontal direction according to the deflection of the electron beam. Parabolic current was applied to 3) to form a barrel-type magnetic field on the vertical coil, and to form a pincushion magnetic field on the horizontal deflection coil so that the deviation of concentration in the fluorescent surface 6 was corrected.

However, this is because the overfocus component appearing in the distance difference in the horizontal direction when the electron beam is deflected to the periphery can be accurately focused by offsetting the pincushion type magnetic field caused by the deflection yoke, that is, the underfocus component, but in the vertical direction, The over-focusing component due to the distance difference of overlaps with the focusing of the barrel-type magnetic field due to the deflection yoke, that is, the overfocus component, causing a problem in that the vertical spreading phenomenon occurs severely.

In more detail, as shown in FIGS. 4A and 4B, a non-uniform magnetic field divided into a vertical barrel and a horizontal pincushion magnetic field is a bipolar component that deflects the electron beam in the vertical and horizontal directions, as shown in FIG. 4C. It can be divided into quadrupole components with horizontal divergence of the electron beam by the pincushion magnetic field and vertical focusing of the electron beam by the barrel magnetic field. In particular, the quadrupole component acts as a kind of lens so that the electron beam is deflected toward the periphery of the screen. As shown in FIG. 4C, a phenomenon in which the focus of the screen is distorted in the vertical or horizontal shape, that is, astigmatism is generated.

This causes high resolution horizontal cores diverging in the horizontal direction at the periphery of the screen and over-focusing in the vertical direction, and high density haze, which is a low density of superimposition phenomenon, at the periphery of the screen, resulting in degradation of the resolution at the periphery of the screen.

Fig. 6A shows in detail the deviation of the electron beam exhibited by the deflection yoke.

Although astigmatism occurs due to the components of the fine pincushion or barrel magnetic field, even in the case of near-uniform magnetic fields, it is natural to cause further distortion in the periphery of the screen when non-uniform magnetic fields are adopted.

This means that the larger the water tube, or the larger the deflection angle, the larger the astigmatism becomes.

This is one of the problems that must be solved in consideration of the tendency of consumers who prefer large floating tubes and the increasing deflection angle according to the size of the receiving tubes.

In order to solve the above problems, there have been methods of correcting astigmatism in synchronization with a deflection signal when the electron beam is deflected to the periphery of the screen. The general method is to divide the focusing electrode into two and configure the first and second focusing electrodes. In addition, a potential difference is generated in the quadrupole electrode provided between the electrodes so that astigmatism is corrected as a magnetic field by the quadrupole lens.

As shown in FIGS. 5A and 5B, the conventional exemplary embodiment divides the focusing electrode 26 into two and receives the first focused electrode 261 and the first focused electrode 261 which are always applied with the same fixed voltage. The second focusing electrode 262 is disposed next to and receives a variable voltage, and the second focusing electrode 262 has a variable voltage such that a potential difference of about 300V to 1000V may occur depending on the amount of deflection of the electron beam. 5C, a dynamic lens was formed on the first and second focusing electrodes 261 and 262 so that astigmatism could be corrected.

To this end, first and second electron beam through holes 263 and 264 are formed at opposing end surfaces 265 and 266 of the first and second focusing electrodes 261 and 262, where the size of the first electron beam through holes 263 is formed. Is formed larger than the electron beam through hole 264 of the second focusing electrode 262 so that the burring portion 267 formed in the second electron beam through hole 264 may be inserted into the first electron beam through hole 263. The burring portion 267 includes a pair of upper and lower burring portions whose horizontal portions are cut off.

In the conventional electron gun provided with such a correction means, the electron beam 1 formed in the triode 21 passes through the first and second electron beam through holes 263 and 264 of the first and second focusing electrodes 26. After focusing by the electrostatic lens according to the voltage difference between the voltages of the first and second focusing electrodes 26 and the positive electrode, the deflection yoke 3 is deflected to each area of the screen, wherein the electron beam 1 is centered on the screen. In case of scanning, the same voltage is applied to the first and second focusing electrodes 26 so that a potential difference does not occur between the first and second focusing electrodes 261 and 262, but the electron beam 1 When deflecting to the peripheral portion, the voltage of the second focusing electrode 262 is dynamically changed according to the amount of deflection of the electron beam 1, so that a potential difference occurs between the first and second focusing electrodes 261 and 262.

Accordingly, the quadrupole lens operates between the first and second focusing electrodes 261 and 262 to change the electron beam 1 into an elongate shape before the electron beam 1 passes through the main lens, so that the transverse yoke is generated by the deflection yoke. The long astigmatism could be corrected.

When the quadrupole lens is used as described above, the correction process of the electron beam caused by the deflection yoke is shown in detail in FIG. 6B.

However, despite the advantage that the astigmatism can be corrected by applying a quadrupole lens to the focusing electrode as described above, there are three problems that are difficult to produce an electron gun by applying the conventional astigmatism correction means to the focusing electrode as follows. have.

First, as described above, since the difference between the voltages applied between the first and second focusing electrodes 261 and 262 is about 300V to 1000V, when the discharge occurs between the two electrodes, the life of the water pipe and the driving chassis may be fatally damaged. do.

In order to prevent this, the first and second focusing electrodes 261 and 262 must maintain a gap of about 0.6 mm, which is a discharge preventing interval, and a burring portion 267 and a first inserted into the first electron beam through hole 263. The spacing of the electron beam through holes 263 should also be maintained so as not to cause a discharge depending on the width of the burring portion 267.

Like the electron gun currently applied in production, this means that the pitch S, which is the distance between the electron beam through holes 263 and 264 and their central axes, is 5.5 mm, and the diameter D2 of the second electron beam through hole 264 is 4.0. mm, the thickness t of the member constituting the electron gun is 0.33 mm, the bridge width (bmm), which is an interval between the first electron beam through holes 263, and the first electron beam through holes 263 and the burrs are discharged. In the case where the electron gun must be designed by restricting the distance to the ring portion 267 (α> 2mm), the diameter D1 of the first electron beam through hole 263 should be at least 5.06 mm (4 mm (D2) + 0.33 mm). T) × 2 + 2mm (α) × 2} or more, so that the bridge width b remains only 0.46mm.

Accordingly, heat is applied to the bridge b in the beading process of assembling the electron gun, and deformation occurs in the bridge b.

In order to form a burring inside the electron beam through hole to prevent deformation of the bridge (b), two burring electrodes are formed between the electron beam through holes, that is, on both sides of the bridge (b). The contradiction of having to form a mm burring electrode makes it impossible to manufacture an electron gun.

Second, it is assumed that an electron gun is manufactured with the above specifications more relaxed.

A mandrel was inserted into each of the electron beam through holes 263 and 264 from the control electrode to the anode electrode, and a pair of bead glasses were fused on both sides of the electrode to fix each electrode relatively to complete the electron gun. Since the inner diameter of the electron beam passing hole 263 of the first focusing electrode 261 is larger than the outer diameter of the mandrel, the first focusing electrode 261 is not securely fixed to the mandrel, and shaking occurs in the first focusing electrode 261 during the beading. There is a problem that does not exhibit the characteristics of the electron beam as designed during operation.

Third, according to the conventional case, the electron beam through hole 263 of the first focusing electrode 261 or the burring part 267 of the second focusing electrode 262 should be designed according to the size of the receiving tube. There is a hassle to produce a mold.

SUMMARY OF THE INVENTION The present invention is to solve the problems described above, and changes the specifications such as the thickness of the member forming the electron gun by changing the shape of the first electron beam through hole of the first focusing electrode or the diameter of the second electron beam through hole of the second focusing electrode. It is an object of the present invention to provide a focusing electrode of an electron gun for a color cathode ray tube having a shape of a first electron beam through-hole which can have a design margin without limitation.

It is another object of the present invention to provide a focusing electrode of an electron gun for a color cathode ray tube which prevents the first focusing electrode from moving during a beading process, which is one of the electron gun assembly steps by providing a fixing means fixed by a mandrel in the first focusing electrode. Is in.

It is still another object of the present invention to provide a focusing electrode capable of accommodating to some extent an operating characteristic of an electron gun which varies according to the size of a receiver tube.

Features of the present invention for achieving the above object, the upper and lower burring portion of the second electron beam through hole inserted into the first electron beam through hole and the upper and lower portions of the first electron beam through hole affected by the raw material thickness of the burring portion The length of the left and right parts that are not affected by the thickness is a little longer.

Another feature for achieving the object of the present invention is to arrange the internal electrode having a third electron beam through hole coaxially with the first electron beam through hole in the interior of the first focusing electrode and the diameter of the third electron beam through hole is mandrel It is formed to be supported when is inserted.

Another feature for achieving the object of the present invention is to accommodate the operating characteristics according to the size of the electron gun by varying the depth of the inner electrode is installed in the first focusing electrode.

1 is a cross-sectional view showing the schematic installation of the electron gun in a general color water tube.

FIG. 2 is a cross-sectional view illustrating a schematic structure of the electron gun of FIG. 1.

3 is an exemplary diagram showing deviation of the focus when the deviation of the electron beam due to the deflection is not adjusted when the electron beam is deflected.

4A, 4B, 4C, and 4D show a non-uniform magnetic field of the deflection yoke,

4A is an exemplary diagram showing a distribution of a pincushion type magnetic field and a shape in which pixels formed by an electron beam are distorted in a horizontal direction.

4B is an exemplary diagram showing a distribution of a barrel-shaped magnetic field and a shape in which a pixel formed by an electron beam is distorted in the vertical direction.

4C illustrates an example in which pixels are distorted in the periphery of the screen due to astigmatism.

4D is an exemplary diagram illustrating a state in which pixels are corrected at the periphery of the screen by the astigmatism correction means of the present invention applied to the focusing electrode.

5A, 5B, and 5C show a focused electrode divided into two parts of a conventional electron gun.

5A is a perspective view.

5B is a longitudinal cross-sectional view illustrating a coupling portion of the first and second focusing electrodes.

FIG. 5C is an exemplary view showing that a quadrupole lens is formed between the first and second focusing electrodes to change the electron beam into an elongated shape.

6A and 6B show an electron beam deflection due to a deflection yoke,

6A is an electron beam trajectory illustrating a process of shifting focus when a quadrupole lens is not used.

6B is an electron beam trajectory showing a process of correcting focus when a quadrupole lens is used.

7A, 7B, and 7C illustrate electron gun focusing electrodes of the present invention.

7A is a perspective view.

7B is a front view of the first focusing electrode terminal opposite to the second focusing electrode.

7C is a front view of the second focusing electrode terminal opposite to the first focusing electrode.

8A, 8B, and 8C are exemplary diagrams showing another shape of the first electron beam through hole of the present invention.

9 is a graph showing the degree of deflection of the electron beam according to each dimension of the focusing electrode of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG.

A color cathode ray tube focusing electrode of the present invention disposed after a triode which forms three electron beams and focuses the electron beam is provided next to the first focusing electrode 1 and the first focusing electrode 1 to which a fixed voltage is applied. The second focusing electrode 2 is arranged in the second focusing electrode 2 and is applied with a variable voltage according to the deflection amount of the electron beam by the deflection yoke.

First and second electron beam passing holes 5 and 6 through which three electron beams pass are formed in opposing end surfaces 3 and 4 of the first focusing electrode 1 and the second focusing electrode 2, respectively.

In addition, an internal electrode 7 is provided inside the first focusing electrode 1 to which the same voltage as the first focusing electrode 1 is applied, and the first and second focusing electrode ends are disposed on the inner electrode 7. Similarly to 3 and 4, the third electron beam through hole 8 through which three electron beams pass is formed.

In particular, the third electron beam through hole 8 has a central axis coinciding with the second electron beam through hole 6, and is formed in the same length as the second electron beam through hole 8 to fix the electron gun. By this, the first focusing electrode 1 can be fixed.

The second electron beam through hole 6 is burring, but the horizontal portion is cut off to form a pair of upper and lower burring portions 9 in the second electron beam through hole 6, the direction of which is the first electron beam through hole 5. The burring part 9 is inserted into the first electron beam through hole 5 so that the difference between the fixed voltage applied to the first focusing electrode 1 and the variable voltage applied to the second focusing electrode 2 As a result, a quadrupole lens is formed between the burring portion 9 and the second electron beam passing hole 6.

In addition, since the main lens component is weakened by the magnetic field during the operation of the 4-pole lens, the focusing ability of the main lens with respect to the outer electron beam is lowered, so that the eccentric distance S 'of the first electron beam passing hole 5 is reduced to the second electron beam. It is made smaller than the eccentric distance S of the through-hole 6 so that the fall of the main lens focusing ability with respect to an outer electron beam can be corrected.

That is, since the distance between the outer portion 9 of the outer passage hole 5 of the first electron beam passage hole 5 and the outer portion of the burring portion 9 is narrowed, the focusing ability of the outer electron beam is enhanced when the quadrupole lens is operated. The deterioration of focusing ability can be corrected.

Since the burring portion 9 formed in the second electron beam through hole 6 is inserted into the first electron beam through hole 5, its size is larger than that of the second electron beam through hole 6, and the shape thereof has a horizontal diameter Rs. The vertical diameter Rv is larger in length to accommodate the thickness of the upper and lower burring portions, and to prevent the discharge phenomenon between the burring portion 9 and the first focusing electrode end 3. Keep the gap.

The elongated first electron beam through hole 5 may be formed in a straight polygon or a curved circle as shown in FIG. 8, and may be formed by curved a portion of the polygon as a combination thereof. have.

As such, the design values for each component of the present invention can be obtained through computer three-dimensional simulation, and the process is as follows.

The quadrupole lens operates by the potential difference when the fixed voltage is about 300V to 1000V lower than the variable voltage.The quadrupole lens can correct the astigmatism by generating a correction magnetic field on the quadrupole lens as much as the astigmatism that occurs when the electron beam is deflected to the periphery of the screen. have.

The computer three-dimensional simulation method measures the focus voltage at the screen center, top, edge, and corner portions when the astigmatism correcting means does not operate.

When the focus voltage is measured, the focus voltage for the change in the horizontal direction is almost constant, and the focus voltage in the vertical direction changes exponentially.

,

,

라고 할때 이들 값이 최종적으로 개선해야할 수차성분이 된다.Therefore, the horizontal aberration component is excluded from each aberration component to be improved, and the focus voltage at each point minus the focus voltage of the center is obtained.

,

,

These values are the aberration components to be finally improved.

The components of the aberration to be improved are divided into focal length, divergence angle, electron beam radius, and the like. The correction is performed by the gap between the first and second focusing electrodes, the depth of the internal electrode, and the size of the burring portion, that is, the length ( Hei), thickness (t) and angle (Alp) are adjusted to obtain approximate dimensions of the quadrupole lens by computer simulation to produce the same aberration component values as are caused by the deflection yoke.

The sensitivity of the electron beam that changes according to the dimensions of the focusing electrode thus obtained is shown in the graph of FIG. 9, where the X axis represents the amount of dimensional change by 0.1 mm, and the Y axis represents the amount of change in the focal length of the electron beam. The upper part shows the horizontal focusing characteristic of the electron beam, and the lower part shows the horizontal focusing characteristic of the electron beam, and the results can be summarized as shown in the following table.

division Internal electrode depth Horizontal Height of burring electrode Burling Angle Spacing between the first and second focusing electrodes Horizontal focusing force diffusion diffusion Focus Focus diffusion Vertical focusing force Focus Focus diffusion diffusion Focus

In particular, as can be seen in the graph of FIG. 9, the height Hei of the upper and lower burring portions 9 and the horizontal diameter Rs of the first electron beam passing hole 5 are most sensitive to the change in the X-axis, and the first electron beam As the size of the horizontal diameter Rs of the through hole 5 decreases, the action of the quadrupole lens becomes stronger.

In the present invention, in order to correct the main lens focusing ability with respect to the outer electron beam, the eccentric distance S 'of the first electron beam passing hole 5 is smaller than the eccentric distance S of the second electron beam passing hole 6 to make the outer electron beam. This is also the reason why the main lens focusing ability deterioration is reduced.

The horizontal diameter Rs and the burring length Hei are diverged and focused on the amount of change in the X-axis, and appear as much as the change value of the depth Dep of the internal electrode. It is possible to change the focal length simply by the depth of the internal electrode without special change of (Hei).

On the other hand, the schematic design dimensions of the present invention are as follows.

* Long electrode

. Horizontal diameter (Rs): 4.6mm

. Vertical diameter (Rv): 7.0mm

. Thickness (t): 0.4mm

. Depth of Distance (S '): 5.46mm

Burring

. Length: 0.5mm

. Alp: 60 °

. Thickness (t): 0.4mm

* Depth of internal electrode: 3.5mm

* Spacing between the first and second focusing electrodes: 0.5 mm

As described above, the present invention extends the upper and lower portions of the first electron beam passing hole into which the burring portion is inserted, that is, to form a longitudinal shape, thereby providing a free space in which the burring portion can be formed in the bridge. It is possible to apply it in actual operation, and to obtain an effect of eliminating astigmatism generated at the periphery of the screen as shown in Fig. 4D.

In addition, by providing an internal electrode having a third electron beam through hole fitted into the outer diameter of the mandrel inside the first focusing electrode, it is possible to prevent the first focusing electrode from shaking in the beading process, thereby producing a precise electron gun. By adjusting the depth at which the inner electrode is installed on the focusing electrode, even if the specification of the electron gun changes according to the size of the receiving tube, only the focusing electrode can accommodate the change of the capacity of the electron gun without any other design change.

Claims (5)

The first focusing electrode disposed after the triode forming the electron beam and focusing the electron beam is applied with a fixed voltage, and the second focusing electrode is placed next to the first focusing electrode and receives a variable voltage according to the deflection amount of the electron beam. The first and second electron beam through-holes and the second electron beam through-holes are formed by dividing the second focusing electrode and formed on opposite ends of the first focusing electrode and the second focusing electrode, respectively, and are inserted into the first electron beam through-hole. In the electron gun for color cathode ray tube which consists of a pair of upper and lower burring part which the horizontal part which cut | disconnected, and a 4-pole lens is formed between the said burring part and the 1st focusing electrode end which opposes a 2nd focusing electrode when a variable voltage is applied, The first electron beam passing hole is formed in an elongated shape, And an inner electrode having a third electron beam through hole which is coaxial with the second electron beam through hole in the first focusing electrode, and is arranged in the coaxial line. The method of claim 1, The focus distance of the electron gun for color cathode ray tube, characterized in that the eccentric distance of the second electron beam through hole is less than or equal to the eccentric distance of the first electron beam through hole. The method of claim 1, The focusing electrode of the electron gun for color cathode ray tube, characterized in that the first electron beam passing hole has a curved shape. The method of claim 1, The focusing electrode of the electron gun for color cathode ray tube, characterized in that the first electron beam passing hole is a polygon. The method of claim 1, The focusing electrode of the electron gun for color cathode ray tube, characterized in that the first electron beam passing hole is a polygon in which a portion is curved.

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