KR100852108B1 - Eelectron gun and CPT therewith - Google Patents

Abstract

According to the invention, a cathode for emitting an electron beam; A control electrode disposed close to the cathode and having an electron beam passing hole through which an electron beam passes, and an elongated slot formed around the electron beam passing hole formed at an exit surface that is a rear surface of an incident surface facing the cathode; A screen electrode disposed close to the control electrode and having an electron beam passing hole through which an electron beam passes, and a horizontal slot formed around the electron beam passing hole formed in an incident surface facing the control electrode; And at least one focus electrode disposed in front of the screen electrode.

Description

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

1 is a schematic cross-sectional view of a colored cathode ray tube according to the prior art;

FIG. 2 is a schematic cross-sectional view of an electron gun provided in the color cathode ray tube of FIG. 1. FIG.

3 is an exploded perspective view of a portion of FIG. 2;

Figure 4 is an exploded perspective view of a part of the electron gun for color cathode ray tube according to the present invention.

5 is a cross-sectional view of the electrodes of FIG. 4.

6 shows the change in the focus tracking voltage according to the depth of the slot in the control electrode and the size of the diameter of the electron beam.

7 shows the change in the focus tracking voltage according to the depth of the slot in the screen electrode and the size of the diameter of the electron beam.

<Brief Description of Major Codes in Drawings>

12.Panel 14.Neck

16. Funnel 18. Display Screen

36. Control electrode 38. Screen electrode

51. Control electrode 52. Screen electrode

The present invention relates to an electron gun for a color cathode ray tube and a color cathode ray tube having the same, and more specifically, for a color cathode ray tube having an elongated slot formed on an exit surface of the control electrode and a transverse slot formed on an incident surface of the screen electrode. An electron gun and the color cathode ray tube provided with the same are provided.

Typically, the color cathode ray tube is equipped with an electron gun. The electron beam incident from the electron gun is deflected to enter the fluorescent film formed on the inner surface of the panel to excite the phosphor, thereby displaying a predetermined image. The electron gun is provided with a cathode for emitting an electron beam, a control electrode, a screen electrode, and a focus electrode.

1 and 2 are views of the color cathode ray tube disclosed in US Pat. No. 4,523,123 and an electron gun provided therein.

1 is a schematic cross sectional view of a conventional colored cathode ray tube.

Referring to the drawings, the color cathode ray tube 10 includes a bulb 11 composed of a funnel 16 and a panel 12, a shadow mask 24 provided inside the panel 11, and the funnel 16. The deflection yoke 30 provided in the outer side and the electron gun 16 provided in the neck 14 of the funnel 16 are provided. The fluorescent film 22 is formed in the inner surface of the panel 11.

In the color cathode ray tube 10 having the above-described configuration, the electron beam 28 incident from the electron gun 26 is deflected by the deflection yoke 30 to the fluorescent film 22 through the through hole formed in the shadow mask 24. Will be reached. The electron beam reaching the fluorescent film 22 can display an image by exciting the phosphor, and the observer can recognize the display screen by observing the display screen 18.

Shown in Figure 2 is a schematic cross-sectional view of a conventional electron gun provided in the color cathode ray tube.

Referring to the drawings, the electron gun is disposed in order in front of the cathode assembly 34, the cathode assembly 34, the control electrode 36, the screen electrode 38, the first acceleration and the focus electrode ( 40, a second acceleration, and a focus electrode 42. In the second acceleration and in front of the focus electrode 42, a shield cup 48 is disposed, and the electrodes and the shield cup 48 are supported by each other by being fused to the bead glass support 32. As is known, the electrodes are labeled G1, G2, G3 and G4, respectively.

The control electrode 36 has an electron beam passing hole 56 through which an electron beam incident from each cathode assembly 34 corresponding to red, green, and blue passes. In addition, an electron beam through hole 58 corresponding to the screen electrode 38 is formed. The first acceleration and focus electrode 40 is formed by welding two cup members 44 and 46 to each other, and electron beam through holes 54 and 52 are formed in each of them. Similarly, the electron beam passage hole 50 is also formed in the second acceleration and focus electrode 42.

Meanwhile, slots 60, 62, and 64 are formed in the screen electrode 38 corresponding to each of the electron beam through holes 58. The slots 60, 62, 64 are formed on the exit side of the electron beam, which is the upper surface of the screen electrode 38 as seen in the figure.                         

3 shows a schematic exploded perspective view of the control electrode 36 and the screen electrode 38 of the electrodes of FIG. 2.

Referring to the figure, an electron beam passing hole 36c through which electron beams of red, green, and blue pass is formed in the incident surface 36a of the control electrode 36. In addition, a longitudinal slot 30b extending in the longitudinal direction is formed corresponding to the electron beam through hole 36c. The elongated slot 30b is formed by partially thinning the thickness of the control electrode 36. The incident surface 36a of the control electrode 36 is a surface facing the cathode 34 in FIG. 2, and the electron beam generated from the cathode 34 is directed to the incident surface 36a of the control electrode 36. Incident. The back surface of the incident surface 36a of the control electrode 36 shown in the figure becomes an exit surface.

On the other hand, the screen electrode 38 disposed adjacent to the exit surface of the control electrode 36 is formed with an electron beam through hole 38c through which electron beams of red, green, and blue pass. A crosswise slot 38b extending laterally in correspondence with 38c is formed. The horizontal slot 38b is also formed by partially thinning the thickness of the screen electrode 38. The lateral slot 38b is formed in the exit surface of the screen electrode 38, consequently facing the cup-shaped member of the next focus electrode 40. As shown in FIG.

The electron gun for the color cathode ray tube as shown in FIGS. 1 to 3 has different paths of the red, blue, and green electron beams generated in the low current region and the high current region, so that the incident angle of the electron beam incident on the main lens is different. As a result, each focus voltage has a different characteristic, that is, a different focus tracking voltage. Therefore, there is a problem in that it is difficult to secure a good quality focus quality in both the low current region and the high current region. For example, in the case of the horizontal electron beam, the low current focus voltage (50 µA / gun) is 8.27 kV, whereas the high current focus voltage (200 µA / gun) is 8.10 kV, resulting in a voltage difference of 0.17 kV. In the case of the vertical electron beam, the low current focus voltage is 7.89 kV, whereas the high current focus voltage is 7.57 kV, with a voltage difference of about 0.32 kV. Here, the focus tracking voltage is different from the incident angle to the main lens due to the difference in focus voltage between the high voltage range and the low voltage range of the electron beam. The difference in focus voltage between the high voltage range and the low voltage range is referred to as the focus tracking voltage. Therefore, there is a need for a method of reducing the focus tracking voltage before entering the focus lens.

The present invention has been made to solve the above problems, an object of the present invention is to ensure that the focus tracking voltage has a relatively constant characteristics, an electron gun that ensures good focus quality in both low current region and high current region, It is to provide a color cathode ray tube.

It is another object of the present invention to provide an electron gun and a color cathode ray tube in which an elongated depression is formed on the exit surface of the control electrode, and an elongated depression is formed on the entrance surface of the screen electrode.

Another object of the present invention is to provide an electron gun and a color cathode ray tube capable of adjusting the focus tracking voltage through adjustment in the control electrode and the screen electrode.

In order to achieve the above object, according to the present invention, a cathode for emitting an electron beam; A control electrode disposed close to the cathode and having an electron beam passing hole through which an electron beam passes, and an elongated slot formed around the electron beam passing hole formed at an exit surface that is a rear surface of an incident surface facing the cathode; A screen electrode disposed close to the control electrode and having an electron beam passing hole through which an electron beam passes, and a horizontal slot formed around the electron beam passing hole formed in an incident surface facing the control electrode; And at least one focus electrode disposed in front of the screen electrode.

According to one feature of the invention, the slots are formed to form a thin part of the thickness of the control electrode and the screen electrode.

According to another feature of the invention, the depth of the slot formed in the control electrode is 40 to 50% of the thickness of the control electrode.

According to another feature of the invention, the depth of the slot formed in the screen electrode is 30 to 50% of the screen electrode thickness.

According to another feature of the invention, the depth of the slot formed in the control electrode is 38 to 67% of the depth of the slot formed in the screen electrode.

Also according to the present invention, a cathode for emitting an electron beam; A control electrode disposed close to the cathode and having an electron beam passing hole through which an electron beam passes, and an elongated slot formed around the electron beam passing hole formed at an exit surface which is a rear surface of the incident surface facing the cathode; A screen electrode disposed close to the control electrode and having an electron beam passing hole through which an electron beam passes, and a horizontal slot formed around the electron beam passing hole formed in an incident surface facing the control electrode; And at least one focus electrode disposed in front of the screen electrode. A color cathode ray tube having an electron gun is provided.

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

The electron gun provided with the screen electrode and the color cathode ray tube according to the present invention are basically the same as those described with reference to FIGS. 1 and 2. In more detail, as shown in FIG. 1, the color cathode ray tube includes a bulb 11 including a panel 12 and a funnel 16 having a fluorescent film 22 formed on an inner surface thereof, and the panel 12. ), A shadow mask (24) provided on the inner side, an electron gun (26) provided on the neck (14) of the funnel (16), and a deflection yoke (30) provided on the outside of the funnel (15). Meanwhile, as shown in FIG. 2, the electron gun includes cathode assemblies 34, a plate-shaped control electrode 36, a screen electrode 38, and the screen electrode sequentially disposed in front of the cathode assembly 34. A first acceleration and focus electrode 40 and a second acceleration and focus electrode 42 disposed in front of 38 and formed of at least one cup-shaped electrode.

4 is an exploded perspective view showing a control electrode and a screen electrode provided in the electron gun for the color cathode ray tube according to the present invention.                     

Referring to the drawing, an electron beam passing hole 51c through which the electron beams of red, green, and blue pass is formed in the emission surface 51a of the control electrode 51. Moreover, the longitudinal slot 51b extended in the longitudinal direction is formed corresponding to the electron beam through hole 51c. The elongated slot 51b is formed by partially thinning the thickness of the control electrode 51. The emission surface 51a of the control electrode 51 is the back surface of the surface facing the cathode 34 in FIG. 2, and the electron beam generated from the cathode 34 has the back surface of the emission surface 51a at the entrance surface. Incident, it exits from the exit surface 51a through the electron beam through-hole 51c.

On the other hand, the screen electrode 52 disposed adjacent to the exit surface of the control electrode 51 is formed with an electron beam through hole 52c through which red, green, and blue electron beams pass, and the electron beam through hole A horizontal slot 52b extending laterally corresponding to 52c is formed. The horizontal slot 52b is also formed by partially thinning the thickness of the screen electrode 52. Since the horizontal slot 52b is formed at the entrance surface of the screen electrode 38, the concave slot 51b formed at the exit surface 51a of the control electrode 51 and the screen electrode 52 are formed. The horizontal slots 52b formed in the incident surface 52a face each other.

5 is a cross-sectional view of the control electrode and the screen electrode shown in FIG.

Referring to the drawings, the thickness of the control electrode 51 is indicated by t1, and the depth of the slot 51b formed therein is indicated by s1. In addition, the thickness of the screen electrode 52 is denoted by t2, and the depth of the slot 52b formed therein is denoted by s2.                     

According to one feature of the invention, the thickness t1 of the control electrode 51 is 0.2 mm, the depth s1 of the slot 51b is 40 to 50 of the thickness t1 of the control electrode 51. Is preferably%. In addition, the thickness of the screen electrode 52 is 0.4 to 0.5 mm, and the depth s2 of the slot 52b formed therein is preferably 30 to 50% of the thickness t2 of the screen electrode 52. At this time, the depth s1 of the slot 51b formed in the control electrode 51 is preferably maintained in the range of 38 ml to 67% of the depth s2 of the slot 52b formed in the screen electrode 52. Both the electrode thickness and the slot depth are experimentally obtained.

6 shows the change in the focus tracking voltage according to the depth of the slot in the control electrode and the size of the diameter of the electron beam.

Referring to the figure, the reference numeral 61 denotes the horizontal focus tracking voltage, and the reference numeral 62 denotes the vertical focus tracking voltage. The horizontal focus tracking voltage 61 increases as the depth of the slot increases, and the vertical focus tracking voltage 62 also increases as the depth of the slot increases. Therefore, in the control electrode 51 shown in FIG. 4, as the depth of the slot 51b increases, the focus tracking voltage increases, which means that the smaller the depth of the slot 51b is advantageous to the focus tracking characteristic. .

On the other hand, the reference numeral 63 denotes the electron beam diameter in the horizontal direction, and the reference numeral 64 denotes the electron beam diameter in the vertical direction. As shown in the figure, it can be seen that as the depth of the slot 51b in the control electrode 51 increases, the diameter of the horizontal electron beam decreases while the diameter of the vertical electron beam increases. Accordingly, it can be seen that the smaller the depth of the slot 51b is, the more favorable for the diameter of the vertical electron beam, but the disadvantage for the diameter of the horizontal electron beam.

Indeed, in selecting the depth of the slot, other conditions such as the degree of degradation of the diameter of the horizontal electron beam and the characteristics of the dynamic voltage should be considered. Therefore, as described above, the depth of the slot 51b that satisfies various conditions is preferably about 0.08 to 0.1 mm corresponding to about 40 to 50% of the thickness of the control electrode 51.

7 shows the change in the focus tracking voltage according to the depth of the slot 52b in the screen electrode 52 and the size of the diameter of the electron beam.

Referring to the figure, the reference numeral 71 denotes the horizontal focus tracking voltage, and the reference numeral 72 denotes the vertical focus tracking voltage. The horizontal focus tracking voltage 71 increases as the depth s2 of the slot increases, and the vertical focus tracking voltage 62 also increases as the depth s2 of the slot deepens. Therefore, as in the control electrode 51, the focus tracking voltage increases as the depth of the slot 52b increases in the screen electrode 52. The smaller the depth of the slot 52b is advantageous to the focus tracking characteristic. It means.

Further, reference numeral 73 denotes the electron beam diameter in the horizontal direction, and reference numeral 74 denotes the electron beam diameter in the vertical direction. As with the control electrode, it can be seen that as the depth of the slot 52b in the screen electrode 52 increases, the diameter of the horizontal electron beam decreases while the diameter of the vertical electron beam increases. Thus, it can be seen that the smaller the depth of the slot 52b is, the more favorable for the diameter of the vertical electron beam, but the disadvantage for the diameter of the horizontal electron beam. However, the smaller the depth of the slot, the better, there is a limit to the range that satisfies other conditions.

In practice, the depth of the slot 51b which simultaneously satisfies various conditions in selecting the depth of the slot is about 0.25 mm, which is about 30 to 50% of the thickness t2 of the screen electrode 52 as described above. It is preferable. That is, when the thickness t2 of the screen electrode 52 is 0.4 mm, the depth s2 of the slot 52 is preferably 0.12 to 0.2, and the thickness t2 of the screen electrode 52 is 0.5 mm. In this case, the depth s2 of the slot 52 is preferably 0.15 mm to 0.25 mm.

As already mentioned above, the depth of the slots 51b and 52b is not necessarily the smaller the better, and not only the focus tracking voltage but also other parts to be considered in the electron gun design, such as COEK characteristics, must be considered. Therefore, it is desirable to be in the above range.

The following table shows how the focus tracking voltage and the diameter of the electron beam in the vertical direction change by changing the slot depths of the control electrode and the screen electrode, and the thickness of the screen electrode.

division Focus tracking voltage Electron beam diameter Control Electrode Slot Depth / Screen Electrode Slot Depth / Screen Electrode Thickness  level Perpendicular level Perpendicular 0.1 / 0.2 / 0.5mm 172 V 493 V 2.38mm 3.45mm 0.08 / 0.15 / 0.4mm 101 V 287 V 2.76 mm 3.02mm

As can be seen in the table above, the focus tracking voltage can be reduced by decreasing the depth of the slot. At this time, the horizontal mirror tends to slightly increase in the diameter of the electron beam, but this is not only insignificant compared to the reduction of the tracking voltage, but can be corrected at the focus electrode, and the beam diameter of the vertical mirror can be effectively reduced.

The electron gun for the color cathode ray tube according to the present invention has an advantage in that the focus angle is improved since the incident angles of the electron beams generated in the low current region and the high current region may be uniformly incident on the main lens.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely exemplary 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 (6)

A cathode that emits an electron beam; A control electrode disposed close to the cathode and having an electron beam passing hole through which an electron beam passes, and an elongated slot formed around the electron beam passing hole formed at an exit surface that is a rear surface of an incident surface facing the cathode; A screen electrode disposed close to the control electrode and having an electron beam passing hole through which an electron beam passes, and a horizontal slot formed around the electron beam passing hole formed in an incident surface facing the control electrode; And, An electron gun for a color cathode ray tube, comprising one or more focus electrodes disposed in front of the screen electrode in the direction of travel of the electron beam from the cathode. The method of claim 1, The slots are electron gun for color cathode ray tube, characterized in that the thickness of the control electrode and the screen electrode is formed to be partially thin. The method of claim 1, Electron gun for a color cathode ray tube, characterized in that the depth of the slot formed in the control electrode is 40 to 50% of the thickness of the control electrode. The method of claim 1, Electron gun for a color cathode ray tube, characterized in that the depth of the slot formed in the screen electrode is 30 to 50% of the thickness of the screen electrode. The method of claim 1, Electron gun for a color cathode ray tube, characterized in that the depth of the slot formed in the control electrode is 38 to 67% of the depth of the slot formed in the screen electrode. A cathode that emits an electron beam; A control electrode disposed close to the cathode and having an electron beam passing hole through which an electron beam passes, and an elongated slot formed around the electron beam passing hole formed at an exit surface that is a rear surface of an incident surface facing the cathode; A screen electrode disposed close to the control electrode and having an electron beam passing hole through which an electron beam passes, and a horizontal slot formed around the electron beam passing hole formed in an incident surface facing the control electrode; And, And at least one focus electrode disposed in front of the screen electrode in the direction of travel of the electron beam from the cathode.

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