JPH03225733A - Cathode ray tube device and its driving - Google Patents

Abstract

PURPOSE:To obtain a better picture image on the whole surface of a picture plane by changing the strength of an electron lense with synchronizing with the deflection of an electron beam during one scanning period of the deflection scanning of the electron beam. CONSTITUTION:Prescribed voltage is supplied to intermediate electrodes 70 and 80 with a resistor 100, and a variable resistor 105 is connected to the lower end of the resistor 100 to permit the variation of the voltage of the electrodes 70 and 80. A main lense is formed with a fifth electrode 50, the intermediate electrodes 70 and 80, and a sixth electrode 60 to focus the electron beam on a picture plane. The curvature of an equpotential line in a vertical direction becomes smaller than that in a horizontal direction by the effect of the electrode 50 side wall, and a focussing action in the vertical direction becomes stronger than that in the horizontal direction. Consequently the changing of focusing voltage permits giving distortion, so as to offset deflection distortion, to the electron beam to obtain a better picture image in the whole surface of the picture plane.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a cathode ray tube device, and particularly to a cathode ray tube device that makes it possible to obtain a good image over the entire screen of the cathode ray tube, and the cathode ray tube device. This relates to a driving method.

(Prior art) A color picture tube, which is a type of cathode ray tube, needs to reproduce a good image over the entire screen, but generally, even if a good image is obtained in the center of the screen, the periphery is inferior to

The main reason for this is that the deflection magnetic field for deflecting the electron beam is distorted into a pincushion or barrel shape, and as a result, the electron beam is also subjected to deflection distortion.

FIG. 12 shows the shape of an electron beam spot on the screen of such a color picture tube. Even though the beam spot (121) is approximately circular in the center of the screen, the beam spot (123) is a high-brightness area with a long axis in the horizontal direction at the periphery of the screen.
) is a distorted beam spot (122) consisting of halo parts (124) of low brightness above and below.

Therefore, the image quality at the periphery of one screen deteriorates.

A so-called dynamic focus method is known as one of the means for solving this problem. This method aims to eliminate deflection distortion at the periphery of the screen by increasing the focusing voltage and changing the strength of the electron lens in synchronization with the deflection of the electron beam.

There are two known dynamic focus methods: one that simply lengthens the focal length of a rotationally symmetrical electron lens, and the other that applies distortion to the electron beam that cancels out the deflection distortion (Japanese Patent Laid-Open No. 63-943). reference). However, in both cases, a parabolic voltage as shown in FIG. 13, which increases with the square of the amount of deflection, is generally applied to the focusing electrode.

Recently, the screen size of color picture tubes has become extremely large, around 30 inches, and the deflection angle has also increased from 90 degrees to 110 degrees. Also, the curvature of the screen is made flatter, and these factors will further increase the deflection distortion.

When these picture tubes are operated using the dynamic focus method, it is no longer possible to obtain a good image over the entire screen by simply applying a focusing voltage that fluctuates in a parabolic manner as in the past.

In particular, high-definition televisions or picture tubes for high-definition televisions are designed so that the beam spot in the center of one screen is as small as possible, resulting in excessive deflection distortion and fluctuations in the conventional parabolic shape. Focused voltage does not provide sufficient performance.

(Problems to be Solved by the Invention) As mentioned above, when operating modern color picture tubes using the dynamic focus method, it is not possible to simply apply a focusing voltage that fluctuates in a parabolic manner as in the past. It is no longer possible to obtain good images.

In other words, as will be described later, the deflection distortion rapidly increases in the peripheral area of one screen, so that with the conventional parabolic voltage, the deflection distortion is insufficiently corrected, and a good image cannot be obtained.

The method of the present invention was developed in view of the above problems, and it is possible to obtain good images with less deflection distortion over the entire screen even when the screen size and deflection angle are increased, especially in high definition or high quality applications. An object of the present invention is to provide a cathode ray tube device and a method for driving the same.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an electron gun comprising a cathode and a plurality of electrode groups,
In this cathode ray tube device, at least one electron lens is formed by the plurality of electrode groups, and the intensity of the electron lens changes in synchronization with the deflection, and varies at a plurality of rates of change during a single scanning period.

In addition, the electron gun of a cathode ray tube device consists of a cathode and a plurality of electrode groups, and among these electrode groups, the electrode that forms the electron lens changes in synchronization with the deflection of the electron beam, and during one scanning period, the electrode that forms the electron lens changes. A method of driving a cathode ray tube device that supplies variable voltages with different rates of change.

(Function) In the present invention, the intensity of the electron lens is changed during a so-called one scanning period in which the electron beam is deflected and scanned from one periphery of the screen to the center, and then from this center to the other periphery of the screen. By changing it in synchronization with the deflection of the electron beam and having a plurality of rates of change corresponding to the deflection distortion, the deflection distortion that rapidly increases at the periphery of the screen is corrected.

(Example) Examples of the present invention will be described in detail below.

First, FIG. 1 is a schematic sectional view of a color picture tube device to which the present invention is applied. This color picture tube device consists of a panel part (9) coated with a phosphor screen part (9) made of a phosphor that is excited and emits red, green, and blue colors when struck by an electron beam.
8), a shadow mask (11) which is a color selection electrode,
It has a funnel part (12) joined to the panel (8) and a tubular neck part (13) extending thereto.

An electron gun section (14) is inserted into the neck section (13), and a deflection section (15) is attached to the fan and flannel section (12). The three electron beams (B), (G), and (R) emitted from the electron gun section (14) are directed to the deflection section (15).
As a result, the entire screen is converged to approximately one point while being deflected and scanned.

It also includes an operating voltage supply device (16) for driving the color picture tube. The anode voltage, which is the final acceleration voltage, is supplied to a predetermined electrode via an anode button and an internal conductive film (not shown). Other voltages are supplied to predetermined electrodes from a conduction terminal (17) provided at the end of the neck (13).

Next, the above-mentioned electron gun section will be explained. FIG. 2 is a schematic cross-sectional view of the electron gun section. In Fig. 2, a heater (not shown) is installed, and - three cathodes arranged in a straight line (
K), first electrode (10), second electrode (20), third electrode (30), fourth electrode (40), fifth electrode (50),
Two intermediate electrodes (70), (80), a sixth electrode (60), and a convergence cup (90) are arranged in this order and supported and fixed by an insulating support rod (not shown).

This electron gun section is equipped with a resistor (ioo), one end (110) of which is connected to the sixth electrode (60), and the other end (
120) is the ground, and the intermediate point (130), (140
) are connected to predetermined intermediate electrodes (70) and (80), respectively.

Further, an operating voltage supply device (16) is connected to one end (110) of the resistor (100).

The first electrode (10) and the second electrode (20) are thin plate-shaped electrodes, and three electron beam passage holes of small diameter are bored therein. The third electrode (30) and the fourth electrode (40) each have two
The cup-shaped electrodes are arranged so that their open ends are butted against each other.

The fifth electrode (50) is composed of a plurality of cup-shaped electrodes, each of which has three large-diameter openings. The intermediate electrodes (70) and (80) have three large-diameter holes formed in a thick plate electrode. The sixth electrode (60) is composed of two cup-shaped electrodes, each of which has three openings. Note that all the holes are circular holes from the first electrode to the sixth electrode.

A DC voltage of, for example, about 150 V and a modulation signal corresponding to an image are applied to the cathode (K). The first electrode (10) is in contact, and approximately 600V is applied to the second electrode (20). The third electrode (30) and the fifth electrode (50) are connected within the tube, and approximately 7 kV is applied to provide a focusing voltage. Fourth electrode (4
0) is connected to the second electrode (20) inside the tube.

6th electrode (60) 4. : 25kV ~ 30
A final acceleration voltage on the order of kV is applied.

The resistor (100) supplies the intermediate electrode (70) with a voltage that is approximately 40% of the high voltage, and the intermediate electrode (80) with a voltage that is approximately 65% of the high voltage. Resistor (10
A variable resistor (105) is connected to the lower end of the tube outside the tube, and the voltage of the intermediate electrodes (70) and (80) can be varied by this variable resistor (105). . Fifth electrode (50), intermediate electrode (70), (8
0) and the sixth electrode (60) form a main lens that finally focuses the electron beam onto the screen. Since the main lens area of such a main lens is expanded by the intermediate electrodes (70) and (80), it is called an extended electric field lens and can be made into a long focal length lens.

When looking at the focused electric field penetrating into the fifth electrode (50), this electron gun section has the following effects due to the influence of the side wall of the fifth electrode (50):
The curvature of the vertical equipotential lines becomes smaller than the curvature of the horizontal equipotential lines, and the focusing effect in the vertical direction becomes relatively stronger than in the horizontal direction. In other words, this electron gun has two quadrupole acids with orthogonal polarities in the main lens, and by changing the focusing voltage, it applies distortion to the electron beam that cancels out the deflection distortion. ing.

The focusing voltage applied to this electron gun (14) is applied to a dynamic focus circuit (150) that generates a parabolic waveform, and a third electrode (30) and a fifth electrode (5) to which the focusing voltage is applied.
0) through a diode element (160) that clamps the parabolic waveform, as shown in FIG.
In the area where the amount of deflection is approximately one-third of the amount at the center of the screen, the voltage is the same as that at the center of the screen, that is, a straight line, and when the amount of deflection increases beyond that, it increases approximately in a square curve of the amount of deflection. There is.

Next, the optimum focusing voltage on the screen of the color picture tube according to the present invention will be explained.

The curve indicated by the dotted line A in FIG. 4 has a parabolic shape, that is, a square curve, with its origin at the center of the screen.

If the color picture tube is operated by applying a focusing voltage VD that fluctuates in a parabolic manner, for example, as shown in FIG.
), a good electron beam spot can be obtained, but the electron beam spot becomes large in diameter due to insufficient focusing in the middle part of the screen (261). Further, the peripheral portion (263) becomes an electron beam spot where deflection distortion is not sufficiently eliminated.

On the other hand, in the area near the center of the screen indicated by the solid line B in Figure 4, the fluctuation is a straight line (B-1), and in the area where the deflection distance is large, it is a parabolic waveform, that is, a squared curve (B-2). When the focusing voltage VD is applied and the operation is performed, as shown in FIG.
63), a small-diameter, high-quality electron beam spot can be obtained over the entire screen.

Here, in a 32-inch color picture tube, the present inventors
Screen horizontality when a conventional parabolic waveform focusing voltage (A) shown in FIG. 4 and a waveform focusing voltage (B) in which the rate of change is different in the vicinity of the center of the screen and in the periphery during one scanning period according to the present invention are applied. FIG. 7 shows the electron beam diameter measured along the axis expressed as a relative value with respect to the value at the center of the screen.

That is, the data indicated by dotted line A in FIG. 7 is the electron beam diameter when a conventional parabolic waveform is applied, and as explained using FIG. , the electron beam diameter becomes significantly large due to insufficient focusing.

On the other hand, the electron beam diameter when applying focusing voltages with different rates of change during one scanning period according to the present invention is shown by the solid line B, but the electron beam diameter at the middle part of the screen is reduced by more than 20%, and This is because the electron beam diameter gradually increases from the center to the periphery.

I was able to obtain clear images with almost no discomfort.

Furthermore, by applying the focusing voltage shown in Fig. 3,
The main electron lens of the electron gun shown in Figure 2 has a different rate of change in intensity at the middle of the screen and at the periphery of the screen, and therefore has two rates of change during one scanning period. .

Furthermore, the rate of change of the focusing voltage with respect to the amount of deflection shown in FIG. 3 also has a straight line and a square curve.
This results in a rate of change of two.

In the above explanation, a case has been described in which the focused voltage varies in a straight line and a square curve during one scanning period, but the present invention is not limited to this. For example, as shown in FIG. 8, The intensity of the main lens increases by 2 during the above-mentioned one scanning period.
Even if the focusing voltage waveform has two rates of change, a square curve and a cube curve may be combined as the focused voltage waveform. Furthermore, as shown in FIG. 9, a variable voltage may be formed such as a straight line, that is, a 1.0th power curve in the central part of the screen, a 2.5th power curve in the middle part, and a 4th power curve in the peripheral part. In the embodiment shown in FIG. 9, the intensity of the main electron lens will have three rates of change during one scan period.

Such a fluctuating voltage having a plurality of different rates of change during one scanning period produces isolated rectangular pulses A and B as shown in FIG.
, C, etc. can be easily generated by superimposing them.

In the conventional example shown in FIG. 13, the focusing voltage changes in a parabola shape instead of a square curve during one scanning period, and therefore the rate of change in the intensity of the electron lens is constant at the square power, and the focusing voltage The rate of change of the voltage with respect to the amount of deflection is also constant as the square.

Although the above explanation has been made regarding horizontal deflection, it goes without saying that the present invention can also be applied to vertical deflection.

Furthermore, as for the electron gun method, the case where the main electron lens section of the resistor built-in compound electron gun shown in FIG. It can also be applied to That is, JP-A-61-742
The present invention can also be applied to an electron gun as shown in FIG. 11 proposed in Publication No. 46. In this electron gun method, the intensity of the auxiliary electron lens section, indicated by G4, changes in synchronization with the deflection, and the main electron lens section formed by the electrodes G and Gs is supplied with a constant voltage. The strength of the main electron lens portion is constant regardless of the deflection. In this case, a voltage is applied to the electrode forming the auxiliary electron lens such that the intensity of the lens portion varies at a plurality of rates of change in synchronization with the deflection.

Furthermore, like the electron gun proposed in Japanese Patent Publication No. 59-53656, the second electrode, which is the accelerating electrode, is divided into three electrode elements, and the middle electrode element is charged with a voltage that changes in synchronization with the deflection. In this case as well, the voltage that changes in synchronization with the deflection changes at multiple rates of change to prevent an increase in deflection distortion around the screen. This is similar to the example.

The embodiments of the present invention can be applied not only to the main electron lens section of an electron gun as described above, but also to all systems in which the electron lens section formed by other electrode groups is changed in synchronization with deflection.

Further, in the above embodiment, a three-electron beam system has been described, but the present invention is also applicable to a one-electron beam system, a two-electron beam system, and the like.

Furthermore, the present invention is applicable regardless of whether the electron beam arrangement is a so-called in-line type or a delta type.

Furthermore, the present invention can be applied to a conventional in-shell electron gun system such as a pi-potential type or a uni-potential type.

[Effects of the Invention] As described above, according to the present invention, a very good image can be obtained not only in the center of the screen but also throughout the middle and peripheral areas of the screen, resulting in high definition and high resolution images. Since a high quality color receiver can be provided, its industrial value is extremely high.

[Brief explanation of drawings]

1 is a schematic configuration diagram of a color picture tube device according to the present invention, FIG. 2 is a schematic sectional view showing an enlarged electron gun of the color picture tube device of FIG. 1, and FIG. 3 is a diagram of the color picture tube device shown in FIG. FIG. 4 is a diagram showing the state of change in focusing voltage for explaining the driving method of the color picture tube device of the present invention, and FIG. FIG. 5 is a diagram showing the electron beam spot on the screen when operating with a conventional focusing voltage, FIG. 6 is a diagram showing the electron beam spot on the screen when operating with the focusing voltage according to the present invention, FIG. 7 is a diagram showing the electron beam diameter when applying a focusing voltage according to the conventional method and the present invention, FIGS. 8 and 9 are diagrams showing changes in the focusing voltage according to other embodiments of the present invention,
FIG. 1O is a diagram for explaining the generation principle for obtaining the focused voltage waveforms shown in FIGS. 8 and 9, FIG. 11 is a schematic diagram of another electron gun that can implement the present invention, and FIG. This figure shows the shape of an electron beam spot on the screen of a conventional color picture tube, and FIG. 13 is a diagram showing changes in the focusing voltage for operating the conventional color picture tube.

Claims (4)

[Claims] (1) A phosphor screen section, an electron gun section that emits an electron beam that causes the phosphor screen section to emit light, a deflection section that deflects and scans the electron beam in the vertical and horizontal directions, and a predetermined part of the electron gun section. a cathode ray tube device comprising an operating voltage supply device for supplying an operating voltage of A cathode ray tube device characterized in that the intensity of the electron lens changes in synchronization with the deflection of the electron beam and has a plurality of different rates of change during one scanning period. (2) The intensity of the electron lens is characterized in that the amount of deflection of the electron beam is the same as the intensity at the center of the phosphor screen in a region of at least 1/3 or less of one scanning period from the center of the phosphor screen. The cathode ray tube device according to claim 1. (3) a phosphor screen unit; an electron gun unit that emits an electron beam that causes the phosphor screen unit to emit light; a deflection unit that deflects and scans the electron beam in vertical and horizontal directions; A method for driving a cathode ray tube device comprising an operating voltage supply device for supplying an operating voltage, wherein the electron gun section includes a cathode and a plurality of electrode groups, and the electrode group forms at least one electron lens. , at least one electrode forming the electron lens is supplied with a variable voltage that changes in synchronization with the deflection of the electron beam and has a different rate of change during one scanning period by the operating voltage supply device; A method for driving a cathode ray tube device characterized by: (4) The variable voltage is the same as the voltage at the center of the phosphor screen in a region where the amount of deflection of the electron beam is at least 1/3 or less of one scanning period from the center of the phosphor screen. Item 3. A method for driving a cathode ray tube device according to item 3.