KR100447648B1 - Electron gun for CRT - Google Patents

Abstract

The present invention relates to an electron gun for color cathode ray tubes.

The configuration of the present invention, a cathode that includes a plurality of electrodes, such as a cathode for emitting an electron beam toward the phosphor screen, a first electrode, a second electrode, a third electrode and a fourth electrode sequentially arranged at a predetermined interval from the cathode. In a conventional electron gun, a connector for applying a voltage to the electrode is composed of a voltage conductor portion for applying a voltage and an electrode connector portion for maintaining a gap between the electrodes; The voltage conductor part and the electrode connector part have different stiffness and thickness from each other, and the electrode connector part has a bent part.

Therefore, according to the present invention, the sameness of luminance and color coordinates of the back raster of the initial monitor screen can be obtained, and the effect of preventing the change over time can be obtained.

Description

Electron gun for color cathode ray tube {Electron gun for CRT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to an electron gun for a color cathode ray tube for stabilizing luminance and color coordinates of a back raster of a monitor screen at an early stage.

1 is a view showing a schematic configuration of a general color cathode ray tube, the front glass of the panel 1 and the rear glass of the funnel (2) are combined, the inner surface of the panel 1 is a fluorescent surface that plays a predetermined light emitting role ( 4), a shadow mask 3 for screening the color of the electron gun 9, which is the source of the electron beam 6 that emits the fluorescent surface 4, and a predetermined phosphor, and the shadow mask 3 being supported. It consists of a frame assembly (7), and a reinforcing band (11) wrapped around the funnel (2) to ensure safety.

The spring (8) for coupling the frame assembly (7) with the shadow mask (3) to the funnel (2), and the inner shield for shielding so that the cathode ray tube is less affected by the external geomagnetic field during operation, the main It is sealed with high vacuum while fixed to the frame.

The operating principle of the color cathode ray tube disclosed in FIG. 1 is as follows.

In the electron gun embedded in the neck of the funnel 2, the electron beam 6 strikes the fluorescent surface formed on the inner surface of the panel 1 by the anode voltage applied to the cathode ray tube, before the electron beam reaches the fluorescent surface. The deflection yoke 5 is deflected up and down and left and right to form a screen.

In addition, there are 2, 4, and 6 pole magnets that modify the trajectory of the electron beam 6 so as to strike a predetermined phosphor, thereby preventing poor color purity.

Since the cathode ray tube is made of high vacuum, it can easily be deflated due to external impact, so that the stress band of the cathode ray tube in a high vacuum state is dispersed and introduced by installing a reinforcing band 11 in the skirt of the funnel 2 to prevent this. Secure impact performance.

FIG. 2 is a view illustrating the inside of the electron gun 9, and a voltage conductor portion 19 for applying a voltage to the second electrode 14 and the fourth electrode 18 is attached to the stem pin 16. It is a figure which shows the electron gun.

In FIG. 2, the cathode assembly 12 of the electron gun, the first electrode 13, and the second electrode 14 are called a three-pole portion, and the structural connection of the three-pole portion is a back raster of a monitor screen of a color cathode ray tube. Raster) brightness and color coordinates are affected.

That is, the wiring method of each of the electrodes becomes a factor influencing the back raster of the screen, and thus changes over time in the luminance and color coordinates of the back raster of the screen.

When the voltage for which the cathode 15 and the cathode assembly 12 are thermally stabilized is higher than the voltage Ekco at which the cathode 15 starts hot electron emission, when the power is applied to drive the color cathode ray tube, the cathode 15 is driven. More current than the current of the voltage (Ekco) starting the hot electron emission flows to the cathode, the overshoot as shown in Figure 3 occurs in the back raster of the initial monitor screen.

In FIG. 3, section I is a section in which the cathode rapidly thermally expands. In section II, the expansion of the cathode is slowed and the first electrode and the cathode assembly are thermally expanded. In section III, the second electrode is expanded as the first electrode is slowed. And a section that contracts.

In addition, undershoot shown in FIG. 3 is caused by the current flowing in the cathode less than the current in the voltage (Ekco) state in which the cathode 15 starts hot electron emission due to the opposite reason of the overshoot. will be.

Thermal expansion occurs due to overshoot of the cathode, and the gap between the cathode 15 and the first electrode 13 is widened due to the generated thermal expansion.

Equation 1 below shows the effect of the spacing of the electrodes on the cathode current.

* Ec2

D: pore size of the first electrode

d1: cathode to first electrode spacing

d2: thickness of the first electrode

k: Constant (Aging condition, cathode material assembly error)

In order to prevent the gap between the first electrode 13 and the cathode 15 from being widened due to the overshoot phenomenon, conventionally, a loose welding of a plate-shaped connector of 0.3 mm or less is performed on the first electrode. The connection was made.

And, in order to enable automatic welding of the second electrode 14 and the fourth electrode 18 in the stem pin 16 to improve productivity, as shown in FIGS. 2 and 4 (a) and (b). In order to apply a voltage, the voltage conductor part 19 is thicker than a thin plate member and has a larger rigidity. Used.

However, when driving the color cathode ray tube, as shown in FIG. 2, the assembly 12 and the first electrode 13 supporting the cathode are thermally expanded (①, ②) in the screen direction, and the second electrode 14 is made of the first electrode. Thermal expansion (③) in the direction of one electrode 13 changes the spacing of the electrodes.

That is, when the second electrode 14 of the triode is thermally expanded (③) toward the first electrode 13, the amount of thermal expansion of the portion B which is not connected to the portion A connected by the circular wire 19 is changed. A problem arises in that the interval between the first electrode 13 and the second electrode 14 does not become parallel.

The portion (A) connected by the strong and thick wire-shaped voltage conductor portion 19 holds the second electrode 14 when the voltage conductor portion 19 thermally expands so that the spacing hardly changes, while the wiring is not connected. Since the uninterrupted portion B has no elements that are hindered during thermal expansion of the second electrode 14, the portion B is thermally expanded toward the first electrode 13 so that the interval between the first electrode 13 and the second electrode 14 becomes parallel. Cause problems.

The problem of non-uniform spacing between the first electrode 13 and the second electrode 14 as described above is based on Equation 1, and the luminance and color coordinates of the back raster of the initial monitor screen of R, G, and B. To be different.

5 shows an overshoot when attaching the voltage conductor unit according to the prior art.

As shown in FIG. 5, the cathode current of each of R, G, and B changes in an initial 1 minute or so. However, it has been shown that the cathode current of R, G, and B is not stabilized and the cathode current is continuously changed even up to 30 minutes when the thermal expansion is stabilized.

The change of the cathode current causes a change in the luminance of the back raster of the screen over time after the initial white balance setting, and the change in the current of the three cathodes of R, G, and B is not constant. Is different.

Accordingly, an object of the present invention is to solve the conventional problems, and to stabilize the brightness and color coordinates of the back raster of the monitor screen at an early stage by paralleling the distance between the first electrode and the second electrode of the electron gun. There is a purpose.

1 is a cross-sectional view of a typical color cathode ray tube.

2 is a view showing an electron gun with a voltage conductor portion according to the prior art.

3 is a graph showing overshoot.

Figure 4 (a) is a plan view of an electron gun with a voltage conductor portion according to the prior art,

(b) is a side view of an electron gun with a voltage conductor portion according to the prior art;

5 is a graph showing an overshoot when applying the prior art.

6 is a view showing an electron gun with a voltage conductor portion and an electrode connector portion according to the present invention.

7 (a) is a plan view of an electron gun with a voltage conductor portion and an electrode connector according to the present invention;

(b) is a side view of the electron gun attached to the voltage conductor portion and the electrode connector according to the present invention.

8 is a graph showing overshoot when applying the present invention.

*** Explanation of symbols for the main parts of the drawing ***

12: cathode assembly 13: first electrode

14: second electrode 15: cathode

16: Stempin 17: Third electrode

18: fourth electrode 19: voltage conductor portion

20: electrode connection part

The present invention for achieving the object as described above, the cathode, which emits an electron beam toward the phosphor screen, the first electrode, the second electrode, the third electrode, the fourth electrode and the like sequentially disposed with a predetermined distance from the cathode An electron gun for a cathode ray tube including a plurality of electrodes, comprising: a connector for applying a voltage to the electrode comprising a voltage conductor portion for applying a voltage and an electrode connector portion for maintaining an interval between the electrodes; The stiffness of the material of the voltage conductor portion and the electrode connector portion is different. Another technical solution of the present invention includes a cathode which emits an electron beam toward a phosphor screen, and a plurality of first and second electrodes arranged at a predetermined interval from the cathode. In an electron gun for a cathode ray tube including a plurality of electrodes such as one electrode, a second electrode, a third electrode, and a fourth electrode, a connector for applying a voltage to the electrode maintains a distance between the electrode and the voltage conductor portion for applying the voltage. An electrode connector portion; The thickness of the voltage conductor portion and the electrode connector portion is different.

Another technical solution of the present invention is a cathode, which emits an electron beam toward a phosphor screen, a plurality of electrodes such as a first electrode, a second electrode, a third electrode, and a fourth electrode sequentially disposed with a predetermined distance from the cathode. An electron gun for a cathode ray tube comprising: a connector for applying a voltage to the electrode comprises a voltage conductor portion for applying a voltage and an electrode connector portion for maintaining a gap between the electrodes; A bent portion is formed in the electrode connector.

Hereinafter, with reference to the accompanying drawings, the present invention to achieve the above object will be described in detail.

The electron gun of the present invention, as in the prior art, in order to prevent the gap between the cathode 15 and the first electrode 13 due to overshoot of the back raster of the screen, the first electrode ( 13) Loosely weld the plate-shaped connector of 0.3mm or less.

As shown in FIGS. 6 and 7 (a) and (b), a voltage conductor portion 19 for applying a voltage to the electrode between the stem pin 16 and the second electrode is provided. The electrode connector 20 is welded and connected between the second electrode and the fourth electrode to maintain the gap between the electrodes by connecting the electrodes with the electrodes.

Between the stem pin 16 and the second electrode 14, a voltage conductor portion 19 using a conductor having a diameter of 0.5 mm or a thickness is welded as in the prior art, and the second electrode 14 and the fourth electrode are welded. Between the electrodes 18, the electrode connector 20 having the plate-shaped bent portion 21 is welded and connected.

The electrode connector 20 welded between the second electrode 14 and the fourth electrode 18 is a plate-shaped conductor having a thickness of 0.3 mm or less, and is formed between the stem pin 16 and the first electrode 13. It is thinner than the thickness of the welded voltage conductor portion 19.

The electrode connector 20 welded between the second electrode 14 and the fourth electrode 18 is a voltage conductor 19 welded between the stem pin 16 and the first electrode 13. It is weaker than the material stiffness of, and elongation is also 2 times or more.

When driving the color cathode ray tube, as shown in FIG. 2, the cathode 15 thermally expands (1) toward the screen and the first electrode 13 thermally expands (2) in the screen direction.

Thereafter, when the second electrode 14 starts thermal expansion (③) toward the first electrode 13, the second electrode portion B, in which the electrode connector 20 is not connected, is connected to the first electrode 13 without any interference. Heat expansion (③) toward).

In addition, according to the present invention, the second electrode portion A connected to the electrode connector 20 having the plate-shaped bent portion 21 also thermally expands (③) toward the first electrode 13.

When the second electrode portion A thermally expands (③) toward the first electrode 13, the bent portion 21 of the electrode connector 20 to which the second electrode portion A is connected is the second electrode. The portion A is stretched to allow thermal expansion.

Therefore, the second electrode portion A connected to the electrode connector 20 is thermally expanded in parallel with the second electrode portion B not connected to the electrode connector 20.

8 is a graph showing overshoot when the present invention is applied.

According to the present invention, even if the electrode connecting portion 20 is connected to only one side, the movement of the electrode due to heat during thermal expansion becomes free, as shown in FIG. The interval is kept constant.

This achieves the sameness of the screen raster characteristics of the screen and prevents time-varying changes in the luminance and color coordinates of the back raster.

Therefore, according to the present invention, by welding a thin plate-shaped conductor having a bent portion between the second electrode and the fourth electrode with the electrode connector, the gap between the first electrode and the second electrode during thermal expansion due to overshoot. In parallel, there is an effect of stabilizing the luminance and color coordinates of the back raster of the monitor screen early.

Claims (9)

In a cathode ray tube electron gun including a cathode for emitting an electron beam toward the phosphor screen, a plurality of electrodes such as a first electrode, a second electrode, a third electrode and a fourth electrode sequentially arranged at a predetermined interval from the cathode, A connector for applying a voltage to the electrode includes a voltage conductor portion for applying a voltage and an electrode connector portion for maintaining a gap between the electrodes; Electron gun for cathode ray tube, characterized in that the rigidity of the material of the voltage conductor portion and the electrode connector portion. The method of claim 1, The electron gun for a cathode ray tube, characterized in that the rigidity of the material of the electrode connector portion is less than the rigidity of the material of the voltage conductor portion. The method of claim 2, Electrode gun for cathode ray tube, characterized in that the electrode connector is a plate. The method of claim 2, And an elongation of the voltage conductor portion is more than twice the elongation of the electrode connector portion. In a cathode ray tube electron gun including a cathode for emitting an electron beam toward the phosphor screen, a plurality of electrodes such as a first electrode, a second electrode, a third electrode and a fourth electrode sequentially arranged at a predetermined interval from the cathode, A connector for applying a voltage to the electrode includes a voltage conductor portion for applying a voltage and an electrode connector portion for maintaining a gap between the electrodes; Electron gun for cathode ray tube, characterized in that the voltage conductor portion and the electrode connector portion is different in thickness. The method of claim 5, The electron gun for a cathode ray tube, characterized in that the thickness of the voltage conductor portion is thicker than the thickness of the electrode connector portion. The method according to claim 1 and 6, Electron gun for the cathode ray tube, characterized in that the bent portion formed in the electrode connector. delete The method according to claim 1 or 5, And the voltage conductor portion is formed between the stem pin and the second electrode, and the electrode connector is formed between the second electrode and the fourth electrode.