JP2000011915A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount a built-in resistor to an insulating support rod, without narrowing the distance between terminal leads and the inside wall of a neck part. SOLUTION: This cathode-ray tube is formed from a vacuum envelope composed of a neck part receiving a panel part constituting a phosphor screen and an electron gun and a funnel part making the panel part communicate with the neck part, and the electron gun is composed of a negative electrode, multiple grid electrodes used for converging and accelerating an electron beam generated from the negative electrode and arranged in the tube axis direction and an insulating support rod 11 to fix the negative electrode and the grid electrodes with a predetermined arrangement and distance, is composed by providing an internal resistor 12 to feed voltages having different potentials to two or more of different grid electrodes out of the multiple grid electrodes on the surface, opposite to the inside wall of the neck part, on the insulating support rod 11. In this case, the internal resistor 12 has a resistor and two or more terminal leads 12b which are extracted from the resistor and connected to the grid electrodes straddling the insulating support rod 11 and recessed parts 20 to increase the distance between the terminal leads 12b, and the inside wall of the neck part are formed at positions where the terminal leads 12b of the insulating support rod 11 are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube,
In particular, the present invention relates to a cathode ray tube having a built-in resistor for applying voltages having different potential differences to two or more grid electrodes constituting an electron gun housed in the neck portion.

[0002]

2. Description of the Related Art A cathode ray tube, such as a color cathode ray tube used as a television picture tube or a monitor tube of an information terminal, includes:
An electron gun that emits one or more electron beams is built into one end of the vacuum envelope, and one or more color phosphor films are coated on the inner surface of the other end, and the electron beam is two-dimensionally scanned. A deflection yoke installed outside the vacuum envelope for displaying a required image. In addition, many color cathode ray tubes have a built-in shadow mask which is a color selection electrode provided in close proximity to a phosphor screen, and a plurality of electron beams emitted from the electron gun are projected to respective phosphor films to be required. Is displayed.

FIG. 10 is a cross-sectional view illustrating an example of the structure of a shadow mask type color cathode ray tube as an example of a cathode ray tube, 31 is a panel portion forming a screen, 32 is a neck portion for accommodating an electron gun, 33 Is a funnel portion connecting the panel portion and the neck portion, 34 is a phosphor screen which forms a screen on the panel portion by separately applying phosphors of three colors, 35 is a shadow mask which is a color selection electrode, and 36 holds a shadow mask 37, a magnetic shield for shielding external magnetism such as terrestrial magnetism, 38, a mask suspension mechanism for arranging a shadow mask in close proximity to the panel section, and 39, for emitting three electron beams into a common plane. An in-line type electron gun; 40, a deflection yoke for generating horizontal and vertical deflection magnetic fields; 41, an internal conductive film; Magnetic device, 43 stem pins to introduce a video signal or the focus voltage and the like from the signal source, 44 is an anode terminal for supplying a high voltage (maximum voltage Eb) inside conductive film.

In this color cathode ray tube, a panel 31, a neck 32, and a funnel 33 constitute a vacuum envelope. The color cathode ray tube emits three electron beams B emitted from an electron gun 39 housed in the neck 32. The fluorescent screen 34 is two-dimensionally scanned by being deflected in two directions by horizontal and vertical deflection magnetic fields formed by the deflection yoke 40.

The electron beam B is intensity-modulated by a modulation signal such as a video signal supplied from a stem pin 43, and
The color is selected by the shadow mask 35 set immediately before the target and collides with each phosphor to reproduce a predetermined color image.

In order to improve the electron beam formed on the phosphor screen over the entire screen, at least two different high voltages are applied to the focusing lens as a multi-stage lens system including a plurality of grid electrodes. There is known one provided with a built-in resistor for supplying to a grid electrode.

FIG. 11 is a side view of a main part viewed from a direction perpendicular to an in-line direction for explaining an example of the structure of an electron gun having a built-in resistor. FIG. 12 is a main view of the electron gun shown in FIG. 1 is an anode (sixth grid electrode) to which the highest voltage is applied, 2 is a second fifth grid electrode to which a voltage obtained by superimposing a DC voltage and an AC voltage is applied, and 3 is a fifth grid electrode. The second fifth grid electrode 2 and the first forming the quadrupole electron lens.
A fifth grid electrode, 4 is a fourth grid electrode, 5 is a third grid electrode electrically connected to the second fifth grid electrode 2, and 6 is a fourth grid electrode.
A second grid electrode electrically connected to the grid electrode 4, 7 a first grid electrode, 8 a cathode, 9 a heater, 10 an anode 1
A shielding cup 11 fixed to the cathode and each of the grid electrodes in a predetermined order and at a predetermined interval; and 12, a DC voltage from the third grid electrode 5 to the second fifth grid electrode 2 and a second DC voltage. Between the third grid electrode 5 and the first fifth grid electrode 3 in order to apply to the first fifth grid electrode 3 a voltage in which about one third of the AC voltage of the fifth grid electrode 2 is superimposed. Is a built-in resistor electrically connected to. In addition, 14 is an electrostatic quadrupole lens, and 15 is a metal ring for reducing the potential of the inner wall of the neck.

Here, for example, when a DC voltage of 6000 V and an AC voltage of 300 V are applied to the third grid electrode 5, the DC voltage is applied to the first fifth grid electrode 3 via the internal resistor 12. An AC voltage of almost 6000 V, which is almost zero, is applied, and the electrostatic quadrupole lens 14 is formed between the first fifth grid electrode 3 and the second fifth grid electrode 2, so that the focus performance is improved. Improvement can be realized.

FIG. 12 shows a state in which the electron gun shown in FIG. The introduction of a high voltage from the internal conductive film 41 to the anode 1 of the electron gun is performed via a spring contact terminal (not shown) attached to the shield cup.

The high voltage introduced from the internal conductive film 41 to the anode 1 is 20 to 30 kV, and the second fifth grid electrode 2
First fifth grid electrode 3, fourth grid electrode 4, third grid electrode 5, second grid electrode 6, first grid electrode 7, built-in resistor 12
In some cases, a discharge may occur between a low-potential electrode and an anode.

Such a discharge is often induced by an increase in the inner wall potential of the neck portion 41. Therefore, in order to suppress the rise in the potential of the inner wall of the neck portion, the metal ring 15 is provided so as to cross the insulating support, and is heated by high-frequency heating in the manufacturing process of the cathode ray tube, and a part thereof is evaporated to form the neck portion. A technique is employed in which a metal film is vapor-deposited on the inner wall and the insulating support rod to suppress a rise in the potential of the inner wall of the neck portion to prevent discharge.

[0012]

Normally, a built-in resistor in which a stem pin for supplying a focus voltage is connected between the third grid electrode 5 and the first fifth grid electrode 3 by one electrostatic quadrupole lens. Since the metal ring 12 is attached to the first grid electrode 7 from the metal ring 15, it is considered that the discharge from the high voltage side can be prevented by the effect of the deposited film of the metal ring 15.

FIG. 13 is an explanatory view of a state before attachment to a conventional built-in resistor and an insulating support rod, and FIG. 14 is an arrow B in FIG.
FIG. 15 is a sectional view of the insulated support rod of FIG. 13 taken along line A1-A2. FIG. 16 is a perspective view of a main part showing a state where the built-in resistor is attached.

Before mounting, the built-in resistor 12 is formed by coating or embedding a resistor on an insulating plate. As shown in FIG. 14, terminals 12a are provided at both ends of the resistor so as to be parallel to the bottom surface of the insulating plate. A terminal lead (tab) 12b is fixed to the terminal 12a by welding at a welding point 12c. The circled portion in the figure indicates the connection between the resistor and the terminal 12a.

On the other hand, since the cross section of the insulating support rod 11 is substantially rectangular as shown in FIG. 15, as shown in FIG.
A terminal lead 12 for securing connection between the first fifth grid electrode 3 and the third grid electrode 5 to which a voltage is applied from this built-in resistor.
b is the distance between the welding point of the first fifth grid electrode 3 and the third grid electrode 5 and the center of the internal resistor 12.
The width is larger than 1 1/2 and the radial distance from the central axis (tube axis) of the electron gun protrudes from the outer shape of the other grid electrode.

Therefore, in the high voltage processing step in the manufacture of the cathode ray tube, the inner wall of the neck portion whose potential has been raised by the high voltage applied to the anode or the internal conductive film and the terminal lead 12
There is a high possibility that a discharge will occur between the b. When a discharge current flows through the built-in resistor 12, the structure of the resistor changes and the resistance value decreases, and normal voltage cannot be applied.
There is a problem that the disconnection occurs and the voltage is not applied.

When the voltage applied to the focus grid electrode system changes, the focus performance is remarkably deteriorated, resulting in a poor characteristic of the cathode ray tube.

In order to prevent such discharge, there is a method of reducing the voltage in the high-voltage processing step. However, this has the side effect of deteriorating the withstand voltage characteristics of the cathode ray tube and deteriorating the yield. .

An object of the present invention is to provide a highly reliable cathode ray tube having good focus characteristics by solving the above-mentioned problems of the prior art.

[0020]

In order to achieve the above object, the present invention provides at least a plurality of grid electrodes for generating, accelerating, and converging an electron beam, and an insulating support rod fixedly holding each grid electrode. In a cathode ray tube containing an electron gun equipped with a resistor, a concave portion is provided in a portion corresponding to a lead portion of a terminal lead for connecting the built-in resistor to a grid electrode of the insulating support rod, and an inner wall of a neck portion is provided. The distance was secured.

That is, the present invention comprises a vacuum envelope comprising a panel constituting a phosphor screen, a neck for accommodating an electron gun, and a funnel connecting the panel and the neck. A gun, a cathode, a plurality of grid electrodes arranged in a tube axis direction for focusing and accelerating an electron beam generated from the cathode, and an insulating support rod for fixing the cathode and the grid electrodes at a predetermined arrangement and interval. A built-in resistor for supplying a voltage having a different potential difference to two or more different grid electrodes of the plurality of grid electrodes on a surface of the insulating support rod facing the inner wall of the neck portion. The resistor has a resistor, and two or more terminal leads that are drawn out of the resistor and connected to the grid electrode while straddling the insulating support rod, and an arrangement portion of the terminal lead of the insulating support rod. In, and having a recess for separating the spacing between the said terminal lead inner wall of the neck portion.

With this configuration, the connection lead drawn from the built-in resistor does not protrude from the outer shape of the connected grid electrode to the inner wall of the neck portion, thereby preventing discharge.

Further, the present invention is characterized in that the terminal lead of the built-in resistor is drawn out from the surface of the resistor on the insulating support rod side.

According to this configuration, the terminal lead serving as the discharge end does not protrude from the external shape of the built-in resistor, and the effect of preventing discharge is further obtained. If the external shape of the terminal lead does not protrude toward the inner wall of the neck portion when the built-in resistor is mounted on the insulating support rod, the position of the portion where the terminal lead is taken out from the built-in resistor is the above-mentioned insulating support. Needless to say, it is not limited to the rod side cotton.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples.

FIG. 1 is a view for explaining a first embodiment of a cathode ray tube according to the present invention, showing an electron gun in a state before being mounted on a built-in resistor and an insulating support rod, and FIG. 2 is viewed from the direction of arrow C in FIG. FIG. 3 is a side view of the built-in resistor, and FIG.
It is sectional drawing cut | disconnected by C2 line. FIG. 4 is a perspective view of a main part showing a state where the built-in resistor is attached.

The built-in resistor 12 before mounting is formed by coating or embedding a resistor on an insulating plate in the same manner as described with reference to FIG. 13, and as shown in FIG. On the surface facing the insulating support rod 11 so as to be parallel to the bottom surface of the terminal, it is fixed to the resistor portion by caulking or welding, and a terminal lead (tab) 12b is fixed to the terminal 12a by welding. The part shown by a circle in the figure shows this fixed part.

In this embodiment, the concave portion 20 is formed by cutting off the corner of the insulating support rod 11 slightly wider than the width of the terminal lead 12b at the portion where the terminal lead 12b is led to the grid electrode. The concave portion 20 can be easily obtained by forming a convex portion on a press mold at the time of hot press molding of an insulating support rod made of multi-form glass. The concave portion 20 has a shape in which a corresponding portion of the insulating support rod 11 is cut off linearly at an angle α.

As shown in the side view of FIG. 2, the built-in resistor 12 bends an end of a terminal 12a attached to the lower surface of the insulating plate at an angle α, and connects a terminal lead 12b to the bent end at a welding point 12c. Weld and fix. Therefore, the insulating support rod 11
By mounting the built-in resistor 12 on the base plate and aligning the terminal lead 12b thereof with the recess 20 formed in the insulating support rod 11,
The open end of the terminal lead 12b comes into contact with the grid electrode.

As shown in FIG. 4, the terminal leads 12b of the internal resistor 12 are welded to the first fifth grid electrode 3 and the third grid electrode 5. As a result, the terminal lead 12b does not protrude from the insulating support rod 11 toward the inner wall of the neck portion.
A sufficient distance from the inner wall of the neck portion can be secured, and the occurrence of discharge is prevented.

If the terminal 12a can be made sufficiently short, the terminal lead 12b may be bent instead of bending the end at the angle α.

FIG. 5 is a view for explaining a cathode ray tube according to a second embodiment of the present invention in a state before the electron gun is mounted on a built-in resistor and an insulating support rod, and FIG. −
It is sectional drawing cut | disconnected by the D2 line. FIG. 7 is a perspective view of a main part showing a state where a built-in resistor is attached.

The built-in resistor 12 before mounting is formed by coating or embedding a resistor on an insulating plate in the same manner as that described with reference to FIG. 13, and as shown in FIG. On the surface facing the insulating support rod 11 so as to be parallel to the bottom surface of the terminal, it is fixed to the resistor portion by caulking or welding, and a terminal lead (tab) 12b is fixed to the terminal 12a by welding. The circled portions in the figure indicate the fixed portions of the resistor and the terminal.

In this embodiment, the corners of the insulating support rod 11 are cut off substantially in the length direction of the built-in resistor 12 at the portion where the terminal lead 12b of the portion where the built-in resistor 12 is mounted is routed to the grid electrode. 20 is formed. The concave portion 20 can also be easily obtained by forming a convex portion corresponding to the concave portion in the press mold at the time of hot press molding of the insulating support rod made of multi-form glass. This recess 20 is used for the insulating support rod 11.
Is cut off linearly at an angle α.

The structure of the built-in resistor 12 is the same as that of FIG. 2 described above. An end of a terminal 12a attached to the lower surface of the insulating plate is bent at an angle α, and a terminal lead 12b is welded to the bent end at a welding point 12c. And fix it. Therefore, by mounting the built-in resistor 12 on the insulating support rod 11 and aligning the terminal lead 12b with the concave portion 20 formed on the insulating support rod 11, the open end of the terminal lead 12b contacts the grid electrode. become.

As shown in FIG. 7, the terminal leads 12b of the internal resistor 12 are welded to the first fifth grid electrode 3 and the third grid electrode 5. As a result, the terminal lead 12b does not protrude from the insulating support rod 11 toward the inner wall of the neck portion.
A sufficient distance from the inner wall of the neck portion can be secured, and the occurrence of discharge is prevented.

In this embodiment, if the terminal 12a can be made sufficiently short, the terminal lead 12b may be bent instead of bending the end portion at the angle α.

In the above embodiment, the inner surface of the concave portion formed at the corner of the insulating support rod 11 is linear, but the present invention is not limited to this.

FIG. 8 is a perspective view of an insulating support rod for explaining another embodiment of the cathode ray tube according to the present invention. FIG. 8 (a) is a third embodiment modified from the first embodiment, and FIG. Shows a fourth embodiment obtained by modifying the second embodiment. FIG. 9 shows FIG.
It is sectional drawing cut | disconnected along line E1-E2 and line F1-F2 of (a) and (b).

FIG. 8A shows a concave portion 20 'having a convex curved inner surface of the concave portion 20 formed in the insulating support rod 11 described in the first embodiment. FIG. 8B shows the insulating support rod 11 described in the second embodiment.
2 in which the inner surface of the recess 21 formed in the shape 2 is a convex curved surface
1 '. These recesses 20 'or 2
FIG. 9 shows a cross section of the insulating support rod 11 on which 1 ′ is formed.

Similarly, in these embodiments, the terminal lead 12b of the built-in resistor 12 does not protrude from the insulating support rod 11 toward the inner wall of the neck portion, and a sufficient distance is secured between the terminal lead 12b and the inner wall of the neck portion. Discharge can be prevented.

The present invention is not limited to the above-described color cathode ray tube having the in-line type three-electron gun, but can be similarly applied to various cathode ray tubes in which a built-in resistor is mounted on a similar insulating support rod. .

[0043]

As described above, according to the present invention,
In the case where a built-in resistor having at least two or more terminals for supplying or taking out voltage is mounted on the insulating support rod, a sufficient gap between the internal support and the inner wall of the neck portion can be ensured. Discharge generation in the processing step can be suppressed, and a highly reliable cathode ray tube with a built-in resistor can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state before a cathode ray tube according to a first embodiment of the present invention is attached to a built-in resistor and an insulating support rod of an electron gun.

FIG. 2 is a side view of the built-in resistor viewed from the direction of arrow C in FIG. 1;

FIG. 3 is a sectional view of the insulating support rod of FIG. 1 taken along line C1-C2.

FIG. 4 is a perspective view of a main part showing a state where a built-in resistor is attached.

FIG. 5 is an explanatory view showing a state before a cathode ray tube according to a second embodiment of the present invention is attached to a built-in resistor and an insulating support rod of an electron gun.

FIG. 6 is a sectional view of the insulating support rod of FIG. 1 taken along line D1-D2.

FIG. 7 is a perspective view of a main part showing a state where a built-in resistor is attached.

FIG. 8 is a perspective view of an insulating support rod for explaining another embodiment of the cathode ray tube according to the present invention.

9A and 9B are lines E1-E2 and F1-F of FIGS.
It is sectional drawing cut | disconnected along 2 lines.

FIG. 10 is a sectional view illustrating a structural example of a shadow mask type color cathode ray tube as an example of a cathode ray tube.

FIG. 11 is a side view of an essential part for explaining an example of a structure of an electron gun provided with a built-in resistor, viewed from a direction perpendicular to an in-line direction.

12 is a main part plan view of the electron gun shown in FIG. 11 as viewed from an inline direction.

FIG. 13 is an explanatory diagram of a state before attachment to a conventional built-in resistor and an insulating support rod.

FIG. 14 is a side view of the built-in resistor viewed from the direction of arrow B in FIG. 13;

FIG. 15 is a sectional view of the insulating support rod of FIG. 13 taken along line A1-A2.

FIG. 16 is a perspective view of a main part showing a state where a built-in resistor is attached.

[Explanation of symbols]

Reference Signs List 1 anode to which maximum voltage is applied (sixth grid electrode) 2 second fifth grid electrode 3 first fifth grid electrode 4 fourth grid electrode 5 third grid electrode 6 second grid electrode 7 first grid electrode Reference Signs List 8 cathode 9 heater 10 shield cup fixed to anode 1 11 insulating support rod 12 built-in resistor 12a terminal 12b terminal lead 12c welding point 14 electrostatic quadrupole lens 15 metal ring 20, 20 ', 21, 21' insulating support A recess formed in the rod.

Claims (2)

[Claims] 1. A vacuum envelope comprising a panel constituting a phosphor screen, a neck for accommodating an electron gun, and a funnel connecting the panel and the neck, wherein the electron gun comprises a cathode. And a plurality of grid electrodes arranged in a tube axis direction for focusing and accelerating an electron beam generated from the cathode, and an insulating support rod for fixing the cathode and the grid electrodes at a predetermined arrangement and at intervals. A cathode ray tube having a built-in resistor for supplying a voltage having a different potential difference to two or more different grid electrodes of the plurality of grid electrodes on a surface of an insulating support rod facing an inner wall of the neck portion, A resistor connected to the grid electrode extending from the resistor and straddling the insulating support rod;
A cathode ray tube having the above-mentioned terminal lead, and having a concave portion for separating a space between the terminal lead and the inner wall of the neck portion in a portion of the insulating support rod where the terminal lead is arranged; . 2. The cathode ray tube according to claim 1, wherein said terminal lead is extended from a surface of said resistor on a side of said insulating support rod.