JPH06260106A - Electron gun structure - Google Patents

Abstract

PURPOSE:To deflect electron beam toward a prescribed direction without increasing the outer diameter of an electrode and the astigmatism in horizontal direction. CONSTITUTION:An electron gun consists of at least a pair of opposite electrodes; a first electrode means to generate electron beam and a second electrode means which is installed coaxially with the first electrode means composing the first electrode and which composes main lens to converges the electron beam. The aperture center 1301 of the electrode in the low potential side of a pair of opposite electrodes 130, 140 composing the second electrode means is set unevenly to one side to the center axis 170 of the electron beam and at the same time the aperture center 1401 of the electrode 140 in the high potential side of the pair of the opposite electrodes is set unevenly to the other side, the reverse side to the electrode in the low potential side, to the center axis 170 of the electron beam. Consequently, since electron beam passes the part out of the initial passing route direction of the scattering lens formed in the inside of the electrode in the high potential side, the unevenness of the astigmatism to the deflecting direction of the center axis of the electrode in the high potential side is suppressed and the astigmatism is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun assembly, and more particularly, to an electron gun assembly constructed so as to deflect and emit a single electron beam in a predetermined direction, or to a fluorescent screen.
The present invention relates to an electron gun assembly in an in-line type color cathode ray tube configured to horizontally emit an electron beam of a book.

[0002]

2. Description of the Related Art An outline of a conventional cathode ray tube and its electron gun assembly will be described by taking a color cathode ray tube as an example. A cathode ray tube used for color image display is composed of a panel portion which is an image screen, a neck portion which accommodates an electron gun structure, and a funnel portion which connects the panel portion and the neck portion. The funnel portion is fired from an electron gun. A deflecting device for scanning the formed electron beam on the fluorescent screen formed by coating on the inner surface of the panel is mounted.

The electron gun assembly housed in the upper neck portion is provided with various electrodes such as a cathode (cathode electrode), a control electrode, a focusing electrode, and an accelerating electrode. An electron beam from the cathode is applied to the control electrode by a signal. It is modulated and given a required cross-sectional shape and energy through the converging electrode and the accelerating electrode, and is projected onto the phosphor screen. The electron beam is deflected in the horizontal direction and the vertical direction by the deflection device mounted on the funnel portion on the way to reach the fluorescent screen, thereby forming a two-dimensional image on the fluorescent screen (Japanese Patent Laid-Open No. 59-215640). ).

[0004]

In the electron gun assembly having the above-described conventional structure, the central axis of the high potential side electrode of the counter electrode forming the two sets of main lenses for focusing the two electron beams arranged on the outer side. Is displaced to the outside with respect to the central axis of the low-potential side electrode, thereby realizing an asymmetric lens.

That is, a color cathode ray tube using a conventional in-line type electron gun structure in which each of the three electron beams is focused by independent main lenses to excite the three primary color phosphors of red, green and blue. Then, as a means for superimposing reproduced images of three primary colors by three electron beams, the high potential side electrode of the counter electrode forming two sets of main lenses for focusing two electron beams arranged outside The non-axisymmetric lens is realized by displacing the central axis outward with respect to the central axis of the low potential side electrode.

Since an axisymmetric lens is used for focusing the central electron beam, the central electron beam travels straight along a trajectory parallel to the initial passage, while the outer electron beam is diverged inside the high potential side electrode. It passes through a portion deviated from the central axis of the lens in the direction of the central electron beam. This allows the outer two
The electron beams of the book receive a focusing force in the direction of the central electron beam, and the three electron beams are concentrated at one point on the fluorescent screen.

However, since the two electron beams arranged on the outer side pass through the non-axisymmetric lens, three electron beams are generated on the fluorescent screen.
There was a problem that astigmatism in the horizontal direction increased when the electron beam of the present invention was concentrated on one point. The same applies to the case where the single electron beam is deflected in a predetermined direction. An object of the present invention is to solve the above-mentioned problems of the prior art and to deflect the electron beam in a predetermined direction without increasing the outer diameter of the electrode or increasing the astigmatism in the horizontal direction, or An object of the present invention is to provide an electron gun structure capable of concentrating a plurality of electron beams that are substantially parallel to each other at one point on the phosphor screen without increasing the outer diameter of the electrode and increasing the horizontal astigmatism.

[0008]

In order to achieve the above object, the present invention comprises a first electrode means for generating an electron beam, and an electrode constituting the first electrode means, which is arranged coaxially with the first electrode means. In an electron gun assembly including at least a pair of counter electrodes forming second electrode means for forming a main lens for focusing the electron beam, a low potential side electrode of the pair of counter electrodes forming the second electrode means. While displacing the center of the aperture in one direction with respect to the center axis of the electron beam, and the center of the aperture of the high potential side electrodes of the pair of counter electrodes with respect to the center axis of the electron beam It is characterized by being displaced in the other direction opposite to.

In addition, the present invention provides an inline array of 3
First electrode means for generating an electron beam of a book and directing the electron beam toward the phosphor screen along initial paths parallel to each other; and each electron beam for focusing the electron beam on the phosphor screen An electron gun assembly having a second electrode means consisting of a pair of counter electrodes having three openings for forming the substantially individual main lenses in the passage of the three electron beams. The low-potential-side electrodes of the pair of counter electrodes forming the second electrode means have electron beam passage holes for the outer electron beam of the electron beam whose trajectory is the initial passage away from the central axis of the electron gun. The high potential side electrodes of the pair of counter electrodes, which have a central axis deviated inward from the central axis of the initial passage and constitute the second electrode means, are the central axes of the electron gun of the electron beam. The initial passage away from Wherein the electron beam apertures of the outer electron beams to the road becomes a central axis which is offset outwardly with respect to the central axis of the initial path.

[0010]

The first electrode means for generating the electron beam and the second electrode means for forming a main lens for focusing the electron beam are arranged coaxially with the electrodes forming the first electrode means. In the above-described configuration of the pair of opposing electrodes, the electron beam passing through the asymmetric main lens formed inside the low-potential side electrode and the high-potential side electrode has an initial path from the central axis of the opening of the high-potential side electrode. Deflected in the direction. At this time, since the electron beam passes through a portion of the divergence lens formed inside the high potential side electrode, which is offset in the initial passage direction, the deviation of astigmatism in the direction of deviation of the central axis of the high potential side electrode is Suppressed. Therefore, the astigmatism that occurs in the conventional electron gun assembly is reduced.

Further, first electrode means for generating three electron beams arranged in-line and directing these electron beams along initial paths parallel to each other toward the fluorescent screen, and each of the above electron beams. Second electrode means comprising a pair of counter electrodes having three apertures forming substantially individual main lenses for the three electron beams in the path of each electron beam for focusing the light on the phosphor screen. And the low-potential-side electrodes of the pair of counter electrodes that constitute the second electrode means of the outer electron beam whose orbit is the initial passage away from the central axis of the electron gun of the electron beam. In the electron gun structure in which the electron beam passage hole has a central axis that is deviated inwardly with respect to the central axis of the initial passage, the central electron beam is focused by an axisymmetric lens and is moved along the central axis of the electron gun. Go straight, outside Since the electron beam passes outside from the central axis of the focusing lens formed in the low-potential electrode, and passes through a portion deviated from the central axis of the diverging lens formed inside the high-potential side electrode in the central electron beam direction, The deviation of astigmatism in the horizontal direction (in-line arrangement direction) is suppressed, and the three electron beams are concentrated at one point on the fluorescent screen due to the concentration force in the horizontal direction.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a cross-sectional view of a main lens forming electrode portion for explaining a first embodiment of an electron gun assembly according to the present invention, in which 130 is a low potential side electrode which constitutes a pair of electrodes forming a main lens, and 140. Is a high potential side electrode forming a pair of electrodes forming a main lens, 1120 is an opening of the low potential side electrode 130, 1150 is a pair of shield plates provided in the opening 1120, and 1301 is an opening center axis of the low potential side electrode 130. Reference numeral 1220 is the opening of the high potential side electrode 140, 1250 is a pair of shield plates provided in the opening 1220, 1401 is the central axis of the opening of the high potential side electrode 140, and AR is the deflection direction of the electron beam. Incidentally, 170 is an initial passage of the electron beam.

In the figure, the shield plate 1150 is arranged so as to be slightly eccentric from the initial passage (center axis of the opening 1120) 170 of the electron beam in the direction of deflection AR, and the shield plate 1250.
Are arranged so as to be slightly eccentric from the initial passage 170 in the deflection direction AR. When the shield plate is eccentric in this way, the farther the part of the inner wall of the shield plate becomes in the direction eccentric to the central axis, the higher the potential is at the low potential side electrode and the lower potential is at the high potential side electrode. Penetrate deeply, and the equipotential line 200 has a shape inclined in the bending direction AR as shown in the drawing.

As described above, according to this embodiment, the shield plate 1
The central axis 1301 of 150 is eccentrically arranged from the initial passage 170 in the eccentric direction AR, and the central axis of the shield plate 1250 is eccentrically arranged from the initial passage 170 in a direction opposite to the eccentric direction AR. It is possible to suppress the deviation of astigmatism in the bending direction AR and to apply the bending force in the bending direction AR.

FIG. 2 is a sectional view of a main portion of a main lens forming electrode portion for explaining a second embodiment of the present invention in which the electron gun assembly according to the present invention is applied to an in-line type color electron gun having three electron beams. 13 is a low-potential side electrode forming a pair of electrodes forming the main lens, 14 is a high-potential side electrode forming a pair of electrodes forming the main lens, 112, 11
3, 114 are openings of the low potential side electrode 13, 115, 11
6, 117 are shielding plates made of cylinders having the same diameter as the openings 112, 113, 114, and 131 and 133 are central axes of the openings of the low potential side electrode 13, 122, 123, 124.
Is an opening of the high-potential side electrode 14, 125, 126, 127 are shield plates made of cylinders having the same diameter as the openings provided in the openings 122, 123, 124, and 141, 143 are high-potential side electrodes 1.
4 is the central axis of the opening. Note that reference numerals 17, 18, and 19 are initial passages of the electron beam.

In the figure, outer electron beam shield plates 115 and 117 are used to form an electron beam initial passage (opening 112,
The central axis of 114) is slightly eccentric in the central electron beam direction, and the shield plates 125, 127 are slightly eccentric from the initial passage 170 in the central electron beam direction. When the shield plate is eccentric in this way, the farther the part of the inner wall of the shield plate becomes in the direction eccentric to the central axis, the higher the potential is at the low potential side electrode and the lower potential is at the high potential side electrode. Penetrate deeply, and the equipotential lines are inclined toward the central electron beam.

As described above, according to this embodiment, the shield plate 1
The central axes 131 and 133 of 15 and 117 are set to the initial passage 17,
19 are arranged so as to be eccentric in the direction of the central electron beam, and the central axes 141 and 143 of the shield plates 125 and 127 are arranged in the initial passage 1.
By eccentrically arranging from 7 and 19 in the direction opposite to the central electron beam, it is possible to suppress the deviation of astigmatism in the central electron beam direction and to apply the bending force in the bending direction AR.

As a result, the three electron beams can be concentrated on one point on the phosphor screen without astigmatism. FIG. 3 is a schematic cross-sectional view illustrating the structure of an example of a color cathode ray tube having an electron gun assembly according to the present invention, in which 1 is a glass envelope, 2 is a face plate panel, and 3 is a phosphor of three colors. Phosphor screen, 4 a shadow mask, 5 an internal conductive film,
6, 7 and 8 are cathodes, 9 is a first grid electrode, 10 is a second grid electrode, 11 is a third grid electrode, 12 is a fourth grid electrode, 13
Is a fifth grid electrode, 14 is a sixth grid electrode, 15 is a shield cup, 16 is a deflection yoke, and 17, 18 and 19 are initial passages of an electron beam.

In the figure, the electrode forming the main lens of the electron gun assembly housed in the neck portion of the glass envelope 1 has the structure described in the embodiment of FIG. Modulation is performed by a signal applied to the control electrode, and a desired cross-sectional shape and energy are applied through the main lens to cause the phosphor screen 103 to project. On the way to reach the fluorescent screen 3, the electron beam is deflected in the horizontal and vertical directions by the deflection yoke 16 mounted on the funnel portion of the glass envelope 1, and reaches the fluorescent screen 3 through the shadow mask 4 which is a color selection electrode. , A two-dimensional image is formed on the phosphor screen 3.

According to the color cathode ray tube equipped with the electron gun assembly of the present invention, it is possible to reproduce a high-quality color image having a high resolution over the entire phosphor screen and the pre-current region.

[0021]

As described above, according to the present invention,
Since the electron beam passes through a portion of the divergence lens formed inside the high potential side electrode, which is offset in the initial passage direction, the deviation of astigmatism in the direction of deviation of the central axis of the high potential side electrode is suppressed,
Astigmatism is reduced. Also, inlined 3
In an electron gun assembly configured to generate a book electron beam, the central electron beam is focused by an axisymmetric lens and travels straight along the central axis of the electron gun, while the outer electron beam is formed inside the low potential electrode. Since it passes through the outside of the central axis of the focusing lens and passes through a portion deviated in the central electron beam direction from the central axis of the divergence lens formed inside the high potential side electrode,
The deviation of astigmatism in the horizontal direction (in-line arrangement direction) is suppressed, and the three electron beams are concentrated at one point on the fluorescent screen due to the concentration force in the horizontal direction.

This makes it possible to provide an electron gun assembly for a cathode ray tube capable of obtaining a reproduced image of high quality.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a main lens forming electrode portion for explaining a first embodiment of an electron gun assembly according to the present invention.

FIG. 2 is a cross-sectional view of a main lens forming electrode portion for explaining a second embodiment of the present invention in which the electron gun assembly according to the present invention is applied to an in-line type color electron gun having three electron beams.

FIG. 3 is a schematic sectional view illustrating the structure of an example of a color cathode ray tube including an electron gun assembly according to the present invention.

[Explanation of symbols]

130 Low-potential-side electrodes that form a pair of electrodes that form the main lens 140 High-potential-side electrodes that form a pair of electrodes that form the main lens 1120 Openings 1150 of the low-potential-side electrodes 130 A pair of shielding plates provided in the openings 1120 1301 Opening central axis of low potential side electrode 130 1220 Opening of high potential side electrode 140 1250 Pair of shield plates provided in opening 1220 1401 Opening center axis of high potential side electrode 140 AR deflection direction of electron beam 170 Initial stage of electron beam aisle.

Claims (2)

[Claims] 1. A first electrode means for generating an electron beam,
A second lens arranged coaxially with the electrode forming the first electrode means to form a main lens for focusing the electron beam.
In the electron gun assembly including at least a pair of counter electrodes forming the electrode means, the opening center of the low potential side electrode of the pair of counter electrodes forming the second electrode means is set with respect to the central axis of the electron beam. In addition to being displaced in one direction, the opening center of the high potential side electrodes of the pair of counter electrodes is displaced in the other direction opposite to the low potential side electrodes with respect to the central axis of the electron beam. An electron gun structure characterized by the above. 2. A first electrode means for generating three electron beams arranged in-line and directing these electron beams along initial paths parallel to each other toward a phosphor screen, and each electron beam. Second electrode means comprising a pair of counter electrodes having three apertures forming substantially individual main lenses in the path of each electron beam for the three electron beams to focus the light on the phosphor screen. And a low-potential-side electrode of the pair of counter electrodes forming the second electrode means is an outer side of the electron beam whose trajectory is an initial passage away from the central axis of the electron gun. The electron beam passage hole of the electron beam has a central axis displaced inward with respect to the central axis of the initial passage, and the high potential side electrodes of the pair of counter electrodes forming the second electrode means are Out of the electron beam An electron beam passage hole for an outer electron beam having an orbit in an initial passage distant from the central axis of the electron gun has a central axis that is displaced outward with respect to the central axis of the initial passage. Electron gun structure.