JPS6129050A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To heighten resolution and reduce the distortion in deflection and the inclination of raster, by putting a deflecting yoke in a bulb net, securing the yoke to an electron gun, and mounting them at a proper angle. CONSTITUTION:The end portion of the final electrode 14 of an electron gun 10 is formed as a cylindrical electrodes 15 of small outside diameter in order to minimize the eccentricity and inclination of the axis of a deflecting yoke 17. The electrode 15 is inserted into the yoke 17 to make the discrepancy between the axes of the electron gun 10 and the yoke 17 small enough to reduce the overall deterioration in focusing, thereby heightening resolution. It is made possible that after a reflecting plate 34 provided on the yoke 17 is set in an appropriate position, such rotational position of the yoke as to maximize the output of a light receiver 36 at the time of the rotation of the yoke and the electron gun 10 together is determined. The distortion in deflection and the inclination of raster can thus be reduced with high resolution.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a cathode ray tube with high resolution and a small increase in deflection power, and is particularly suitable for use in index type color cathode ray tubes, cathode ray tubes for monochrome displays, etc. Related to cathode ray tube devices.

[Background of the invention]

As shown in Fig. 1, a conventional cathode ray tube has a phosphor screen formed on the inner surface of a panel 1, which generates an electron beam in a pulp neck 2 and generates an electrostatic field that focuses the electron beam on the phosphor screen. It consists of a gun 3 and a deflection yoke 4 that deflects the electron beam to form a raster on the phosphor screen.

By the way, in order to reduce the diameter of the electron beam impinging on the phosphor screen and achieve a high-resolution cathode ray tube, it is necessary to reduce the spherical aberration of the electron lens of the electron gun, especially the main lens. To achieve this, we increased the aperture of the electrodes that make up the main lens.

However, in order to accommodate a large-diameter electron gun, it is necessary to increase the diameter of the valve neck portion 2. but,
As shown in FIG. 1, when the deflection yoke 4 is provided on the outer periphery of the bulb neck, increasing the diameter of the bulb neck reduces the electron beam deflection sensitivity and increases the deflection power. For this reason, in the past, it was not possible to use an electron gun with a sufficient diameter, resulting in insufficient focusing characteristics.

In order to eliminate the above-mentioned drawbacks, as shown in FIG.

Connect the valve neck part of the electron gun to part 2 and deflect the yaw.

It has been proposed to change the diameter of the second section 2'. By enlarging the diameter of the bulb neck section 2 where the electron gun 6 is placed, a large zero diameter electron gun can be used, so it can be used as a main lens with low aberrations and has good focusing characteristics. By reducing the diameter of the portion 2', it is attempted to eliminate deterioration in the deflection sensitivity of the electron beam. However, unlike the conventional cathode ray tube shown in Figure 1, it is no longer possible to insert the deflection yoke 4 from the base 5 side of the cathode ray tube, so it is necessary to assemble the divided deflection yoke over the valve neck. There is. For this reason, it is difficult to assemble the deflection yoke with sufficient accuracy compared to when assembling the deflection yoke alone. Therefore, the shape of the electron beam becomes uneven depending on the direction of deflection of the electron beam, and the diameter of the deflected electron beam also increases.
The disadvantage is that it is not possible to obtain a high-resolution image across the entire screen.

There is.

A cathode ray tube that combines a large-diameter electron gun and electrostatic deflection is also considered, but since electrostatic deflection has lower electron beam deflection sensitivity than electromagnetic deflection using a deflection yoke, it is difficult to obtain the necessary amount of deflection. has the disadvantage that the total length of the cathode ray tube increases.

FIG. 3 shows a cathode ray tube having a large diameter electron gun 3 and a deflection yoke 4 built into the valve neck 2. In this cathode ray tube, since the deflection yoke 4 can be installed near the electron beam, the deflection sensitivity of the electron beam can be improved and a large diameter electron gun with little spherical aberration can be used. Therefore, it is expected that deflection power can be reduced and high resolution image quality can be obtained. However, the large-caliber electron gun 3 is supported in the valve neck 2 via a plurality of tongue-shaped spring pieces 6.
Electron gun caliber part 5' glass and bulb neck 2
Since the glass is welded and sealed, the central axis of the electron gun 3 and the central axis of the valve neck portion 2 tend to be eccentric or tilted.

Therefore, the center axis of the deflection yoke 4 and the valve neck.

Deflection yaw to reduce the eccentricity of the center axis of 2.

Even if RI4 is installed, it will still be an electron gun as mentioned above.

Since it is not possible to reduce the eccentricity or inclination of the central axis of the valve neck 2 and the central axis of the electron gun 3, the deflection of the electron gun 3 and the central axis of the valve neck 2 cannot be reduced.

- There is a limit to reducing the eccentricity and inclination of the hook 4. Furthermore, in the case of Fig. 3, the inner diameter of the deflection yoke 4 is made smaller to increase the electron beam deflection sensitivity compared to the case where the deflection yoke is installed around the outer periphery of the bulb neck as shown in Fig. 1. hand.

Therefore, the electron gun 3 relative to the inner diameter of the deflection yoke.

Relative eccentricity between the central axis and the central axis of the deflection yoke 4.

The ratio becomes larger than when a deflection yoke is installed around the outer circumference of the valve neck. For this reason, the electron beam is easily affected by deflection distortion that occurs when the electron beam is deflected, and the shape of the electron beam spot tends to be non-uniform depending on the direction of deflection, resulting in problems in that the overall focusing characteristics deteriorate.

Furthermore, since the deflection yoke 4 is built into the cathode ray tube during manufacture, if the raster is tilted with respect to the phosphor screen after the cathode ray tube is completed, it is impossible to correct the raster tilt.

As a result, the yield of cathode ray tubes decreases. child.

To solve this problem, it is necessary to improve the accuracy of the installation when the deflection yoke 4 is built into the cathode ray tube, but it is not possible to adjust the installation position with the deflection yoke 4 inside the tube. Due to poor workability, the cost of manufacturing cathode ray tubes increases.

Furthermore, the deflection yoke 4 must be fixed after adjustment, but it is difficult to securely fix it because the coefficient of friction of the glass tube is small, and the deflection yoke 4 is also fixed due to vibrations when transporting the cathode ray tube. There is a problem in that the mounting position tends to fluctuate and the raster tends to tilt even after adjustment.

A cathode ray tube having a built-in deflection yoke as shown in FIG. 3 has the disadvantage that the raster inclination is likely to occur, and that the raster inclination cannot be corrected after the cathode ray tube is completed.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned drawbacks and achieve high resolution.

degree, the deflection distortion without increasing the deflection power.

To provide a cathode ray tube with reduced raster inclination.

[Summary of the invention]

In order to achieve the above object, the present invention incorporates a deflection yoke into the valve neck.

Therefore, the deflection power increases when using a large-caliber electron gun.

The outer diameter of the final electrode of the electron gun is reduced.

It has a small cylindrical shape, is inserted into the deflection yoke, and the deflection yoke is fixed to the electron gun via an insulating holder. The integrated electron gun and deflection yoke can be rotated within the tube, and the rotation angle of the deflection yoke can be detected to ensure that the deflection yoke is attached at the correct angle.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. A cathode 10 that emits an electron beam is a cylindrical first grid electrode 11.
It is built into the inside of the device and is heated by a heater (not shown). A cylindrical second electrode facing the first grid electrode 11
A grid electrode 12 is arranged.

be placed. The focus electrode 13 is arranged opposite to the second grid electrode 12°. Best to apply anode voltage.

The final electrode 14 is arranged opposite to the focus electrode 13.

An electron lens is formed in the gap between the focus electrode 13 and the final electrode 14 to focus the electron beam. Each electrode is supported by an insulated support rod 16 and a valve neck 19
Acquired within the department. The final electron gun.

The end of the electrode 14 (the side of the electrode that does not form an electron lens is a cylindrical small-diameter electrode 15 with a small outer diameter. Small-diameter electrode 15
is inserted into the deflection yoke 17, and the fixing band 2 is attached to the small diameter electrode 15 via the insulating material holder 18.
By fixing at 8, the eccentricity between the central axis of the electron gun W and the central axis of the deflection yoke 17 can be reduced. A conductive tongue piece 24 is attached to the tip of the small-diameter electrode 15 as the final electrode, and a conductive film 24 is applied to the anode voltage introduced from the anode button 22 of the bulb by depositing it inside the bulb.
Power is supplied to the final electrode 14 through. In addition, the conductive tongue piece 2
A gator container 25 is attached to the tip of the cathode ray tube to maintain the vacuum level of the cathode ray tube.

After evacuating and sealing, the getter material is evacuated.

Perform a so-called getter flush).

The electron beam emitted from the cathode 10 is the first lattice.

The electric field formed by the electrode 11 and the second grid electrode 12 is focused to create a crossover. .

The light is then focused by the main lens formed by the focus electrode 13 and the final electrode 14 and projected onto the phosphor screen 21 on the inner surface of the panel 20. The larger the inner radius of the focus electrode 13 and the final electrode 14 constituting the main lens, the smaller the spherical aberration, the smaller the diameter of the electron beam on the phosphor screen, and the higher the resolution of the image. I can do it. In this embodiment, the deflection yoke 17 is placed around the outer circumference of the valve neck.As described above, it is possible to increase the diameter of the valve neck without causing the problem of an increase in deflection power as in a cathode ray tube in which a deflection yoke is installed around the outer circumference of the valve neck. Therefore, a large-diameter electron gun with low aberration can be used.

8・ FIG. 5 is for explaining the spherical aberration of the electron gun.

It is a diagram. In the same figure, the horizontal axis is the electric current in the main lens.

The child beam diameter r is the inner diameter of the electrode that constitutes the electron lens.

The value normalized by D is shown. The vertical axis indicates the value of the electron beam diameter on the fluorescent screen. In an ideal main lens without spherical aberration, the electron beam diameter at the phosphor screen -F does not increase even if the electron beam diameter in the main lens increases, as shown by the chain line A. However, a main lens without spherical aberration does not actually exist, and as the electron beam diameter in the main lens increases, as shown by the curved aperture, the electron beam diameter on the phosphor screen increases. electron beam diameter d
It is known that the relationship between the electron beam diameter r in the main lens and the electron beam diameter r is dωr3).

As mentioned above, in order to reduce the electron beam diameter due to spherical aberration on the phosphor screen, it is effective to reduce the electron beam diameter in the main lens. There are two methods for this purpose: making the electron beam incident on the main lens narrower, or increasing the inner diameter D of the electrodes constituting the main lens. Although the former method can reduce the influence of spherical aberration, the diameter of the electron beam on the phosphor screen expands due to the influence of mutual repulsion due to the charges of the electrons themselves. Therefore, it is desirable to increase the inner diameter of the electrode constituting the latter main lens.

However, when the deflection yoke is externally attached, the deflection power increases as explained in the conventional example, so the diameter of the electrode cannot be increased. Therefore, in the embodiment of the present invention, in order to solve the above-mentioned problem, a deflection yoke is built into the tube and the latter method is adopted. The ratio of the electrode inner diameter to the electron beam diameter r is approximately r/
By setting D < 0.2, spherical aberration can be practically ignored.

The electron beam 26 focused by the large-diameter main lens is projected onto the phosphor screen 21 with a small electron beam diameter. On the other hand, the electron beam 2 deflected by the deflection yoke 17
7 is also projected onto the fluorescent screen 21.

In this embodiment, as described in the conventional example, the central axis of a large-diameter electron gun produced during the manufacture of a cathode ray tube and the center of the deflection yoke 17 built into the valve neck 19.

In order to minimize the eccentricity and inclination of the axis, the end of the final electrode 14 of the electron gun W is connected to a cylindrical small-diameter electrode 15 with a small outer diameter.
shall be. Then, the small diameter electrode 15 is inserted into the deflection yoke 17, and the deflection yoke 17 is inserted through the holder 18 made of insulating material.
of the electron gun W by fixing it to the small diameter electrode 15 using the fixing band 28.

Eccentricity between the central axis and the central axis of the deflection yoke 17 is reduced.

As mentioned above, since the tip of the electron gun W is inserted into the deflection yoke 17 and the deflection yoke 17 is fixed, the electron beam generated due to the eccentricity and centering of the center axis of the electron gun and the center axis of the deflection yoke 17 is It is possible to reduce the non-uniformity of the spot diameter over the whole surface, that is, the non-uniformity of the electron beam spot shape depending on the deflection direction of the electron beam, and to reduce the deterioration of the focus over the whole surface.

Therefore, it is possible to obtain a small electron beam diameter over the entire screen using a large-diameter electron gun with little spherical aberration, and to achieve high resolution image quality611.

Wear.

On the other hand, the outer periphery of the deflection yoke 17 is provided with a plurality of tongue-like grooves.

A bling piece 29 is provided and the bias is fixed to the electronic readout.

The facing yoke 17 is located within the valve neck 19 and is connected to the electron gun 1.
Make sure that it can be rotated in unison with 0. FIG. 6 shows a state in which the integrated electron gun and deflection yoke 17 are installed on a rotary table steel having a rotating mechanism when the electron M1o is sealed in the valve neck portion 19 during the manufacture of a cathode ray tube. A support base 32 is provided to which the holder 36 is fitted, and the support base 32 is rotatable.

By rotating the support base 32, the valve neck 1
The electron gun housing 9 and the deflection yoke 17 can be rotated as one unit. A reflecting plate 34 provided on the side surface of the deflection yaw 1' reflects light from a light projecting element 35 such as a laser installed outside the bulb.

The reflected light is received by a light receiver 36 provided outside the pulp.

An optical system composed of a cathode ray tube bulb, the light projecting element 35, and the light receiver 36 is placed in a predetermined position relative to the rotary base steel.

Electrical units arranged in a positional relationship and supported by the rotating table steel.

The child gun is deflected to the electron gun via the support stand 32.

When rotating around the center axis of the holder 17, the counter and receiver.

In order to increase the change in reflected light received by the light device 36,
It is desirable to arrange the optical system on a plane perpendicular to the central axis of the polarization yoke 17.

Next, as shown in FIG. 7, the vertical line to the reflection plate 34 provided on the deflection yoke 1B is the X axis (cathode ray tube).

θ is the angle between the axis parallel to the major axis of the phosphor screen 21 as the X axis and the axis parallel to the minor axis as the Y axis.

(Assuming that the angle shown by the solid line in FIG. 7 is negative), the support base 32 is rotated from a negative value of θ.

Turn the deflection yoke 17 in the forward direction (counterclockwise in FIG. 7).

When the light receiver 36 rotates, the amount of light received by the light receiver 36 changes depending on the rotation angle, as shown in FIG. 8 from the light receiver 36.

A detection output like this can be obtained. Therefore, the position of the reflection plate 34 provided on the deflection yoke 17 is set in advance to an appropriate position, and the deflection yaw is adjusted.

This is the time when the 17 and the electron gun W are rotated as one unit.

The output of the light receiver 36 changes depending on the rotation direction position.

Determine the rotational direction position of the deflection yoke 17 that is maximum.

I can do that. In this way, the deflection yoke 17 turns.

After setting the rotation angle to a correct angle that does not cause raster inclination, a sealing process is performed in which the glass of the diameter 37 portion of the electron gun W and the glass of the bulb neck 19 portion are welded. After sealing the electron gun, it is the same as before.

By performing the same exhaust process as polar ray tubes.

Therefore, a cathode ray tube with less raster inclination can be obtained.

In the above, a reflection plate was installed on the deflection yoke to detect the rotation angle of the deflection yoke, but this is only a part of the electron gun.

The electrodes are arranged in a cylindrical shape to a rectangular shape (for example, the first grid electrode 10
The shape of the electrode does not need to be cylindrical and can be rectangular, and the rotation angle of the deflection yoke is detected by using the side surface of the rectangular electrode as a reflector. You can also do it.

〔Effect of the invention〕

As described above, according to the present invention, the increase in deflection power and the non-uniformity of the electron beam shape due to deflection can be avoided.

It is possible to use a large-diameter electron lens with little spherical aberration without causing spherical aberration, and the resolution of the cathode ray tube can be improved over the entire screen.
Suitable for monochrome display cathode ray tubes and projection cathode ray tubes. Furthermore, since the raster inclination can be reduced, the yield of cathode ray Iif production can be increased, and the economic effects of the present invention are significant.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a conventional cathode ray tube. Figures 2 and 6 are explanatory diagrams of a cathode ray tube using a conventional large-diameter electron gun.
The figure is a sectional view of one embodiment of the present invention, FIG. 5 is an explanatory diagram of spherical aberration, FIG. A plan view showing the part,
FIG. 8 is a diagram showing the rotation angle of the deflection yoke and the output of the light receiver. DESCRIPTION OF SYMBOLS 10... Cathode, 11... First grid electrode 1, 15°12... Second grid electrode, 13... Focus electrode, 14... Final electrode, 16... Insulated support rod, 17 ... Deflection yoke, 20... Pulp panel, 21... Phosphor screen, 28... Fixing band, 30... Rotating table, 31... Base, 32... Support stand, 34...・Reflector, 36... Light receiver.

Claims (1)

[Claims] 1. A cathode ray tube has a single electron gun that generates an electron beam and forms an electrostatic focusing electric field, and a deflection yoke that electromagnetically deflects the electron beam from the electron gun to form a raster. The final electrode of the gun is made into a cylindrical electrode whose outer diameter is smaller than that of the part forming the electron lens, the final electrode with a small diameter is inserted into the deflection yoke, and an insulating material is used. 1. A cathode ray tube device, characterized in that a deflection yoke is fixed to a small-diameter electrode via a holder, and a plurality of tongue-shaped spring pieces are provided on the outer periphery of the deflection yoke.