JPS6282629A - image display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an image display device, in particular, a linear cathode extending parallel to and perpendicular to the screen, and an electrical connection located at the back of the linear cathode and perpendicular to the linear cathode and electrically connected to each other. Regarding an image display device including an electron beam generating section in which a vertical scanning electrode divided into vertical scanning electrodes and a planar grid electrode located in front of a linear cathode and having an electron beam passing hole in a portion facing the linear cathode are arranged, for example,
It is used in flat cathode tubes used in color television receivers, computer terminal displays, etc.

2. Description of the Related Art Conventionally, as shown in FIG. 6, an electron beam generating section in an image display device of this type has a vertical scanning electrode B attached directly to a frame A at its base C, and a planar grid. The electrode is attached via a stay E, and the linear cathode F is attached via a spring G and a fixed base H.

Problems to be Solved by the Invention In the configuration as described above, the portion consisting of the linear cathode F, which is the source of the electron beam, the vertical scanning electrode B, and the planar grid electrode, is the source of the electron beam from the linear cathode F. O of
In order to lower the voltage controlling N, OFF, the mutual distance between the vertical scanning electrode B and the linear cathode F is set to 0.2ffl.
ff, the distance between the linear cathode F and the planar grid electrode is 0.2
MM is extremely small, and at the same time, the linear cathode F
is not in direct contact with the vertical scanning electrode B and the planar grid electrode, and the vertical scanning electrode B must be electrically insulated and positioned, and the assembly accuracy is very high. strict.

However, since each component of the electron beam generating section is individually attached to the frame A either directly or via a fixture, it is difficult to achieve mutual positional accuracy, especially parallelism.

For example, the positional accuracy of the vertical scanning electrode B, the linear cathode F, and the planar grid electrode is 0.2 MM → 0.2+ overall.
If the change is uniform like α, it can be corrected by changing the voltage, but for example, if the position accuracy differs between the center and both ends in the vertical direction, there will be bright and dark areas in the image. A so-called luminance unevenness phenomenon occurs, and there is no means to correct it. Also, if the mutual position accuracy is extremely poor,
Even mutual conduction and generation of an electron beam becomes difficult.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides that the linear cathode does not contact the vertical scanning electrode and the planar grid electrode, and that the linear cathode does not contact the vertical scanning electrode, the linear cathode and the planar grid electrode. It has a structure that satisfies electrical insulation between the electrodes and assembly accuracy, and ensures electrical insulation of each member and images with uniform brightness. , a vertical scanning electrode located at the back of the linear cathode and perpendicular to it and electrically divided from each other, and a planar grid electrode located at the front of the linear cathode and having an electron beam passage hole in the opposite part thereof. A linear cathode is stretched on the back side of a planar grid electrode through an insulated thin wire for positioning the front part of the linear cathode,
Between the planar grid electrode and the vertical scanning electrode, a two-piece spacer that does not interfere with the front part of the linear cathode [the thin deciding wire] is interposed, and the back of the linear cathode is placed on the overlapping surface of one of the spacers. A thin linear insulated wire for positioning the back of the cathode that is received is held in contact with the thin wire for positioning the back of the cathode, and a relief portion for the thin insulated wire for positioning the back of the cathode is provided on the overlapping surface of the spacer.

Function: Due to the structure described above, the linear cathode and the planar grid electrode are insulated by the insulating thin wire for positioning the front side of the linear cathode, and at the same time, the distance between them is maintained at the diameter of the insulating thin wire. In addition, an insulated thin wire for positioning the back side of the linear cathode,
The two-piece spacer that supports and fixes this thin insulating wire prevents the linear cathode from deflecting toward the vertical scanning electrode and insulates the linear cathode and the vertical scanning electrode.

In addition, the two-piece spacer regulates the insulated wire for positioning the back side of the linear cathode at a predetermined position on one overlapping surface,
The relief portion for the thin insulating wire on the other overlapping surface also serves as a portion for holding and positioning the thin insulating wire during assembly. Furthermore, the two-piece spacer overlaps the thin insulating wire with a relief part, so that the distance between the linear cathode and the vertical scanning electrode is regulated by the thickness of the thin insulating wire without being affected by the thin insulating wire. The thickness of each positioning thin insulated wire and spacer is ±2 to the standard value.
Since the accuracy is as high as 3 μm, as a result, the mutual positional accuracy between the vertical scanning electrode, the linear cathode, and the planar grid electrode can be maintained uniformly in the vertical and horizontal planes.

Embodiment FIGS. 1 to 5 show an example of a flat cathode ray tube. In reality, each electrode is housed in a vacuum envelope (glass container), but FIG. 3 shows the entire structure with the vacuum envelope omitted to make the internal electrodes clear. Furthermore, in order to clarify the horizontal and vertical directions of the screen on which two characters, etc. are displayed, the horizontal and vertical directions are illustrated in the face grating section.

Numeral 3 denotes a plurality of linear cathodes, which are long in the V direction and are formed by coating the surface of a tungsten wire with an oxide cathode material, and are arranged independently at equal intervals in the horizontal direction.

On the opposite side of the face plate portion 28 across the linear cathode 3, there are horizontally elongated strips that are electrically divided at equal pitches in the vertical direction on the insulating support θ in close proximity to the linear cathode 3. Vertical scanning electrodes 14 are arranged. These vertical scanning electrodes 14 are formed as independent electrodes corresponding to % of the number of horizontal scanning lines in the vertical direction (approximately 480 in the case of the NTSC system) if a normal television image is to be displayed.

Next, between the linear cathode 3 and the face plate portion 28, the linear cathode 3. A planar electrode with an opening in a portion corresponding to the vertical scanning electrode 14,
The first grid electrode is divided between adjacent linear force swords 3 and has an opening similar to that of the first grid electrode 7 so that a video signal is applied to each electrode to perform beam modulation. , a second grid electrode 15° and a third grid electrode 16 which are not divided in the horizontal direction are arranged. The second grid electrode 15 is used to generate an electron beam from the linear cathode 3, and the third grid electrode 16 is used to shield the beam generation electric field from the electric field generated by the subsequent electrode.

Next, a fourth grid electrode 1a is arranged, the opening of which is larger in the horizontal direction than in the vertical direction. FIG. 4A shows a horizontal section of FIG. 3, and FIG. 4B shows a vertical section of the pot. At the rear of the fourth grid electrode 17, two electrodes 18.8 having openings that are sufficiently wider in the horizontal direction than in the vertical direction, similar to the openings in the fourth grid electrode 17, are arranged. As shown, a vertical deflection electrode is formed by vertically shifting the opening center axes of the two electrodes 18.8. After the vertical deflection electrode 18.8, a plurality of vertically long electrodes are provided between each of the linear cathodes 3 toward the face plate portion 28 side. In this embodiment, a three-stage case is shown as an example, and each electrode is connected to the first horizontal deflection electrode 19. Second horizontal deflection electrode 20. A third horizontal deflection electrode 21 is used, and each horizontal deflection electrode 19, 20° 21 is connected to a common bus line 2 every other horizontal direction.
2,23°24. Third horizontal deflection electrode 2
1 includes a metal bypass electrode 26 of the face plate portion 28.
The same voltage as the DC voltage applied to the first horizontal deflection electrode 19. A voltage for horizontal focusing of the beam is applied to the second horizontal deflection electrode 2Q. A light-emitting layer consisting of a fluorescent surface 27 and a metal back electrode 26 is formed on the inner surface of the zero-face plate portion 28. . On the phosphor surface, in the case of color display, phosphor stripes of light @), green q, and blue (B) are sequentially formed in the horizontal direction via a black guard band.

To explain the operation of such a color cathode ray tube,
The linear cathode 3 is heated by passing a current through it, and the first grid electrode 7. A voltage approximately the same as the potential of the cathode 3 is applied to the vertical scanning electrode 14 . At this time, the first. Second
The beam advances from the cathode 3 toward each grid electrode 7°15, and a voltage higher than the potential of the cathode 3 (e.g. 1 o - 300 V) is applied so that the beam passes through each electrode aperture.
is applied to the second grid electrode 16. Here, the amount by which the beam passes through each aperture of the first and second grid electrodes 7, 15 is controlled by changing the voltage of the first grid electrode 7. The beam that has completely passed through the aperture of the second grid electrode 150 is transferred to the third grid electrode 16 → the fourth grid electrode 1 → the vertical deflection electrodes 18, 8 → the horizontal deflection electrodes 19, 20
．． 21, a predetermined voltage is applied to these electrodes so that the electron beam forms a small spot on the fluorescent surface 26. Here, the beam focus in the vertical direction is determined by the third grid electrode 16. The beam focusing in the horizontal direction is performed by an electrostatic lens formed between the fourth grid electrode 17° and the vertical deflection electrodes 18, 8. This is done with an electrostatic lens formed between each of the third horizontally polarized electrodes 19, 20, 21. The two electrostatic lenses are formed only in the vertical and horizontal directions, respectively, so that the vertical and horizontal spot sizes of the beam can be adjusted individually.

Still number 1. Second. Third horizontal deflection electrode 19°20.21
A sawtooth wave, triangular wave, or staircase wave deflection voltage of the same voltage with a horizontal scanning period is applied to the connected bus bars 22, 23, and 24, and the electron beam is deflected by a predetermined width in the wateron direction, A luminescence image is obtained by scanning the fluorescent surface 26 with an electron beam.

Next, vertical scanning will be explained using FIG. 5.

As described above, by controlling the voltage of the vertical scanning electrode 14 so that the potential of the space surrounding the linear cathode 3 is more positive or negative than the potential of the linear cathode 3, the linear cathode The generation of electrons from 3 is controlled. At this time, if the distance between the linear cathode 3 and the vertical scanning electrode 14 is small, a beam is generated from the cathode 3 (hereinafter referred to as ON).
The voltage for controlling the cutoff (hereinafter referred to as 0FF) may be small. In the case of the current television system that uses an interlaced system, the vertical deflection electrode 1 is
A predetermined deflection voltage is applied to 8.8 for one field, a beam ON voltage is applied to 14A of the vertical scanning electrode 14 for one horizontal scanning period, and the other vertical scanning electrodes (14B,
14C, . . . , 14Z), a beam OFF voltage is applied. After one horizontal scanning period has elapsed, a beam ON voltage for one horizontal scanning period is applied only to the vertical scanning electrode 14B, and then a voltage is applied to the vertical scanning electrode 14 so that the beam is ON only for one horizontal scanning period. When this is completed, the vertical scanning of the first field is completed. In the next second field, the polarity of the deflection voltage applied to the vertical deflection electrode 18.8 is reversed, and this is applied for one field.

The signal voltage applied to the vertical scanning electrode 6 is applied in the same manner as in the first field.

At this time, the amplitude of the deflection voltage applied to the vertical deflection electrode 18.8 is adjusted so that the horizontal scanning line of the second field is located between the horizontal scanning line positions of the beam caused by the vertical scanning of the first field. As described above, the vertical scanning electrode 14 has the first. The same vertical scanning signal voltage is applied to the second field, and the deflection voltage applied to the vertical deflection electrode 18.8 is changed to the first field.
By changing between the first field and the second field,
One frame of vertical scanning is completed.

To further explain the points of the embodiments related to the improvement of the present invention, as shown in FIGS. A plurality of them are arranged independently at equal intervals in the direction, and an appropriate tension is applied in the vertical direction. The number of linear cathodes 3 and the spacing between them are design matters. For example, if the display area is 1
Assuming that it is 0 inch, the horizontal spacing is about 10H pitch, and 20 linear cathodes 3 are arranged horizontally with a length of about 160 mm in the vertical direction.

On the opposite side of the face plate 28 with the linear cathode 3 in between, there are horizontal electrodes disposed adjacent to the linear cathode 3 on the insulating support 6 at equal pitches in the vertical direction and electrically divided. An elongated vertical scanning electrode 14 is arranged. These vertical scanning electrodes 14 are formed as 490 independent electrodes in the vertical direction if normal TV images are to be displayed. Next, the linear force node 3 and the face plate 28
A planar first grid electrode 7 in which an opening for focusing and accelerating the electron beam is formed in a portion corresponding to the linear cathode 3 is arranged sequentially from the linear cathode 3 side. Next, a second grid electrode 16 that is electrically independent and has an electron beam passage hole is arranged corresponding to each linear cathode 3, and a second grid electrode 16 having the same shape as the first grid electrode 16 is arranged. Three grid electrodes 16 are arranged.

Next, horizontal deflection electrodes 19, 20° 21 are used to deflect the electron beam in the horizontal direction (c) as it passes through the electron beam passing hole provided in each electrode 16, 17.8.
are arranged electrically and independently facing the electron beam passing through the aperture of each electrode. Here, the horizontal deflection electrodes 19, 20, 21 are provided with electrically independent metal films on both surfaces of a base such as an insulating support. Next, a layer that emits light when stimulated by an electron beam is formed on the inner surface of the face plate 28 by the phosphor 27 and the metal back layer 26. The phosphor may be formed in one layer for black and white display, but for color display, it is formed as stripes or dots of red, green, and blue sequentially in the east horizontal direction.

In FIG. 1, the part from the first grid electrode to the second vertical deflection electrode 8 is omitted by broken lines, and the parts after the second vertical deflection electrode 8 are also omitted. The portion from the first grid electrode to the second vertical deflection electrode 8 is supported by an insulating stay 12 on a frame 9. Spring 10 and fixing base 11 on both sides of the back of frame 9
The linear cathode 3 is stretched and fixed while applying a constant tension, and the distance between it and the back surface of the first grid electrode 7 is adjusted by the interposition of glass fibers attached above and below with metal pieces 29. There is. Spacer 1゜2 is coated with alumina on both sides for insulation, but since it is necessary to spot-fix the glass fibers N4 and 6 with small metal pieces 13.29, alumina is coated only on the spot-fixed part. It has not been. A pair of spacers 1.2 that are in close contact with the back surface of the first grid electrode 7 and the front surface of the back vertical scanning electrode 14 are interposed, and these spacers 2.3 are also attached to the back surface of the frame body 9 and the front surface of the back vertical scanning electrode 14. It is fixed by 12. The spacer 2 has a mesh shape that does not interfere with the glass fiber 5, and a glass fiber 4 for positioning the back of the linear cathode 3 is attached to the back surface of the spacer 2 by a small metal piece 13. Make a spacer, now 1
When the two spacers 1 are combined, they form a spacer between the back vertical scanning electrode 14 and the first grid electrode 7.

In order to prevent the glass fiber 4 from affecting this spacer function, a relief part 30 is provided by half etching in the portion of the spacer 1 facing the fiber 4. In this embodiment, the distance between the back scanning electrode 14 and the linear cathode 3 is 0.2ff.
ff, there is also Q between the linear cathode 3 and the first grid electrode 7,
2fflJr. This is determined by the optimum electrode configuration that minimizes the spot diameter of the electron beam when it reaches the fluorescent surface 27. In order to obtain this distance with high accuracy, in this embodiment, the first grid electrode 7 has a diameter of 0.0 mm at both ends.
Rear linear cathode 3 with two glass fibers 5 fixed
By stretching and fixing the linear cathode 3, the linear cathode 3 is positioned 02H from the first grid electrode 7. In this state, a fiber fixing spacer 2 in which the glass fiber 4 is fixed with a small metal piece 13 is placed next. The thickness of the fiber fixing spacer 2 is 0.0 mm including the alumina layer coated on both sides.
28, the glass fiber 4 contacts the linear cathode 3 from the vertical scanning electrode 14 side. Next, a back spacer 1 whose portion facing the glass fiber 4 is half-etched is placed. The back spacer 1 has a thickness of 0.2 mm including alumina layers coated on both sides, and the distance from the linear cathode 3 to the vertical scanning electrode 14 is maintained at 0.2 mm.

With this structure, the assembly accuracy from the vertical scanning electrode 14 including the linear cathode 3, which is the source of the electron beam, to the first grid electrode 7 is maintained uniformly in the vertical and horizontal planes, so the brightness on the screen is A uniform image without unevenness can be obtained.

Finally, although glass fiber is used in this text, any thin wire made of insulating material that can be manufactured easily with a predetermined precision may be used.4) Effects of the Invention According to the present invention, the following effects are achieved by the above-mentioned structure and operation.

(1) The mutual positional accuracy from the back vertical scanning electrode centering on the linear cathode, which is the source of the electron beam, to the planar grid electrode has to be determined with good single-item accuracy, such as the thickness of the metal plate and the diameter of the glass fiber. High precision can be achieved by a simple method of combining spacers and insulating IfB wires.

(2) Since both or one side of each of the two spacers is coated with an insulating film, the electrical insulation between the back vertical scanning electrode and the planar grid electrode is also satisfied.

(3) When the internal structure is deformed by external pressure, the linear cathode deforms while maintaining the mutual positional relationship between the back vertical scanning electrode and the planar grid electrode, so there is little effect on the image.

(4) The relief part for the thin insulating wire on one spacer of the two-piece spacer and the other spacer also serves to hold and properly position the thin insulating wire when assembling them, making the assembly work easier. make it easier.

[Brief explanation of drawings]

FIG. 1 is a partially schematic cross-sectional view of an image display device showing an embodiment of the present invention, FIG. 2 is a partially schematic horizontal plan view of the image display device, and FIG.
The figure is a schematic perspective view of the entire image display device, FIG. 4A is a cross-sectional view of FIG. 3, FIG. 4B is a longitudinal sectional view of the same, FIG. 5 is an explanatory diagram of the drive operation of FIG. 3, and FIG. is a partial cross-sectional view showing a conventional example. 1, 2...2 spacers, 3...
Linear cathode, 4, 5... Glass fiber (insulated thin wire), 7... Planar grid electrode, 14...
... Back vertical scanning electrode, 30 ... Relief part. Name of agent: Patent attorney Toshi Nakao and one other person αPatsu! t Fig. 4 Fig. 5 fδ I2c /2Y h

Claims (1)

[Claims] A linear cathode extending vertically parallel to the screen, a vertical scanning electrode located at the back of the linear cathode and perpendicular to it and electrically divided from each other, and a vertical scanning electrode located at the front of the linear cathode and facing it. An electron beam generating part is provided in which a planar grid electrode having an electron beam passage hole is arranged in a part thereof, and a linear cathode is applied to the back surface of the planar grid electrode via an insulated thin wire for positioning the front part of the linear cathode. A pair of spacers that do not interfere with the linear cathode front positioning thin wire are interposed between the planar grid electrode and the vertical scanning electrode, and the linear cathode is placed on the overlapping surface of one of the spacers. An image display device characterized in that a thin insulating wire for positioning the back of a linear cathode is held in contact with the back of the spacer, and an escape portion for the thin insulating wire for positioning the back of the linear cathode is provided on the overlapping surface of the other spacer.