JPH03252030A - Flat display device, its manufacture and jig required - Google Patents

Abstract

PURPOSE:To hold an entire grid electrode by uniform tension in a simple configuration by making up the grid electrode out of metal whose thermal expansion coefficient is greater than those of a front and a rear panel, and thereby disposing it in a hermetic space with its tension state kept as it is provided in advance. CONSTITUTION:A panel shaped grid electrode 5 is made of metal whose thermal expansion coefficient is greater than those of a front panel 1 and a rear panel 2, and it is disposed in a hermetic space between the front and rear panels with its tension state kept as it is provided in advance. In addition, the grid electrode 5 is, if desirable, made up out of a plurality of grid electrode filaments 53 which are mutually kept in parallel, and each grid electrode filament 53 is connected to a grid voltage source via a grid switching means carrying out switching operations in response to an address electrode 44 which is in scanning operation in the horizontal direction. By this constitution, even when a device is subjected to external shock load, the grid electrode is only vibrated with small amplitude accompanied while being prevented from being brought in contact with an address electrode substrate so that an electric circuit is thereby protected.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a device that excites phosphors in a display using an electron beam to display an image, a manufacturing method thereof, and a treatment for installing grid electrodes in a display panel. It's about the ingredients.

(Prior Art) As a display device, the CRT system, in which a phosphor is irradiated with a high-speed electron beam to excite it, is the most excellent in terms of image quality. However, in the case of large-screen previews, if this is done using the CRT method, the weight of the device is 1
As it weighs over 70 kg and is over 850 mm deep, it is difficult to accommodate it for general household use.

Therefore, U.S. Patent No. 4,719,388 or Japanese Patent Publication Nos. 61-242489 and 62-90831
In this issue, an electron beam type flat display was proposed, which was equipped with a line-shaped filament cathode as an electron beam emission source, and a high-speed electron beam extracted by an XY matrix electrode struck a predetermined address on a phosphor screen. There is.

FIG. 12 shows the configuration of a flat display according to the above-mentioned US patent. This is a flat space formed by a front panel (1) with a fluorescent screen (10) on the back side and a back panel (2) with a back electrode (20) on the inside surface, and a linear filament cathode (3). and an address electrode substrate (4), and a filament cathode (
3) and an address electrode substrate (4), a grid-shaped accelerating electrode (5) is arranged in parallel thereto.

The address electrode substrate (4) has first address electrodes (
42), and a second address electrode (44) extending in a direction perpendicular to the address electrode (42) is provided on the other surface of the base (40). Apertures (41) are formed in the address electrode substrate (4) at points where the first address electrode (42) and the second address electrode (44) intersect, respectively. In this device, when a positive voltage is simultaneously applied to two selected address electrodes (42) and (44), an electron beam is extracted from an aperture (41) located at the intersection of these electrodes. , a predetermined address on the fluorescent screen of the front panel (1) to which a high voltage is applied is irradiated to emit light.

This method basically excites the fluorescent screen using the same principle as CRT, so it is similar to other flat display methods.
For example, plasma display panel (FDP) method, liquid crystal display (LCD) method, fluorescent display tube (VF) method, etc.
T) Higher image quality can be obtained compared to other methods.

(Problem to be solved) However, in the case of the conventional example shown in Fig. 12, the grid electrode (
5) is placed close to the address electrode substrate (4), so when an external shock is applied to the device, the grid electrode may vibrate and come into contact with the address electrode substrate (4). There was a problem that it adversely affected the electric circuit of the electrode substrate.

In addition, due to the grid electrode (5)'s own weight, heat generation due to grid current conduction, and temperature rise due to absorption of thermoelectrons emitted from the cathode (3), the grid electrode (5) thermally expands and deforms, causing the address electrode substrate to (4) The distance between them becomes uneven.

In order to further increase the brightness of the phosphor screen, it is necessary to increase the voltage of the address electrode and to increase the beam current by increasing the grid current. However, an increase in the beam current inevitably causes heat generation in the grid electrode, which poses a problem of promoting deflection of the grid electrode due to thermal expansion.

Therefore, a portion of the electron beam hits the address electrode substrate, causing problems such as variations in luminance and deformation of the cross-sectional shape of the beam.

To deal with this problem, it is necessary to support the grid electrode in a tensioned state in advance in the airtight space of the flat display, but it is difficult to deploy the grid electrode tension support mechanism in the flat airtight space. This is difficult and requires a complicated device.

The purpose of the present invention is to clarify a flat display, manufacturing method, and jig in which the entire grid electrode is held with uniform tension using a relatively simple configuration.

(Means for Solving the Problems) The flat display of the present invention has a fluorescent screen (10
), a rear panel (2) arranged parallel to the front panel and forming a flat airtight space between it and the front panel, and a rear panel (2) arranged parallel to the inner surface of the rear panel. A plurality of linear filament cathodes (3) are provided, and an address electrode is provided between the cathodes (3) and the front panel (1) to control and irradiate electrons to specific positions on the phosphor screen (10). A flat panel consisting of a substrate (4) and a panel-shaped grid electrode (5) arranged between the address electrode substrate (4) and the cathode (3) and having a grid surface (50) in which a large number of through holes are arranged. In a display, the grid electrode is formed of a metal material having a coefficient of thermal expansion larger than that of the front panel and the rear panel, and is placed in advance in an airtight space under tension.

Furthermore, the flat display of the present invention includes a plurality of grid electrode strips (53) (53a) parallel to each other.
) (53b), and each grid electrode strip is composed of:
It is connected to a grid voltage source via a grid switching means (7) which switches according to the address electrodes in the horizontal scanning direction during operation.

When manufacturing a flat display, the present invention provides a jig (6) for attaching a grid electrode (5) having a grid surface (50) in which a large number of through holes are arranged above a back panel (2) having a fibment cathode (3). ) to place the address electrode substrate (4) in a tensioned state parallel to the back panel;
A step of arranging the front panel (1) having a fluorescent screen (10) on the back surface in parallel above the address electrode substrate (4).
A step of arranging them in parallel upwardly, and heating the back panel (2), grid electrode (5), address electrode substrate (4), and front panel (1) assembled by the above steps to integrate their respective peripheral edges. a step of removing the jig (6) from the grid electrode (5) and placing the grid electrode (5) under tension in the sealed space between the front panel (1) and the back panel (2); This is a method for manufacturing flat displays.

The jig used to carry out the method of the present invention has a pair of mounting rods (61) (61) arranged in parallel;
(61) are connected by tension rods (60) (60) to form a rectangular frame, and each mounting rod (61)
The presser rods (63) are arranged oppositely, and the mounting rods (61)
A protrusion (62) is provided on one side of each opposing surface of the presser rod (63).
, a concave groove (64) is formed on the other side, and the mounting rod (61) and the holding rod (63) are fitted through the tensioning margin (52) at both ends of the grid electrode (5) between them, and the tensioning rod (60) is characterized in that it is formed of a metal material having a coefficient of thermal expansion larger than that of the grid electrode (5) to be stretched.

(Function/Effect) In the flat display of the present invention, the grid electrode is formed of a metal material with a large coefficient of thermal expansion and is kept in a tensioned state in advance, so even if an external shock is applied to the device, the grid electrode will remain small. It simply vibrates with an amplitude of
The grid electrode no longer comes into contact with the address electrode substrate, and the electrical circuit is protected.

Furthermore, the grid electrode is held in a tensioned state by a jig in advance during manufacturing, assembled between the front panel and the back panel in that state, and integrated by heating, so that when the flat display cools to room temperature, the grid electrode
The greater the amount of contraction of the grid electrode due to the difference in coefficient of thermal expansion between the grid electrode and both panels, the greater the tension, and the tension of the grid electrode can be further strengthened.

When the grid electrode is divided into multiple grid electrode strips,
One grid electrode row (53) corresponds to a predetermined number of address electrode rows in the horizontal direction. The switching means (7) connects one grid electrode strip to the grid voltage source in correspondence with the address electrode in the horizontal scanning direction during operation, and does not apply the grid voltage to the other grid electrode strips.

The range of the grid electrode to which the grid voltage is applied is
Since the width is limited to one grid electrode strip, thermionic electrons emitted from the cathode concentrate on the grid electrode strip to which voltage is being applied, increasing the electron beam density.

Furthermore, even if the amount of power applied to the grid electrode is the same,
By dividing the grid electrode into n pieces and configuring it with n grid lines, the current that can be passed can be increased by n times compared to the case where the grid electrode is not divided, so that the brightness of the phosphor screen can be increased.

(Preferred Embodiment) FIG. 1 shows an example of a color display device configured according to the present invention, in which a front panel (1) and a rear panel (3) are constructed.
) between the address electrode substrate (4) and the grid electrode (
5) are placed.

Front panel (1) has a width of 880 mm and a height of 497 mm.
It is a large panel with a thickness of 3 to 4 mm and a thickness of 3 to 4 mm, and as is well known, the inner surface has a phosphor screen (10 ).

Carbon is coated on the inner surface of the front panel and between the phosphor dots to improve contrast, and these surfaces are covered with an aluminum metal back layer (11) as shown in FIG. 2 to prevent charging.

The back panel (2) is formed by a 3-4 mm glass plate, and its periphery is integrally joined to the inner surface of the front panel (1),
Configures the display panel unit.

On the inside of the back panel (2), attach anchors (30) at both ends.
Line-shaped filament cathode (3) fastened to (30)
is stretched under tension. The cathode has a diameter of 30~
It is a 50 μm tungsten wire coated with an electron emitter material such as barium oxide, and is supported by an anchor (30) away from the rear panel (2) as shown in FIG. The cathodes (3) are stretched in parallel at close intervals, with one cathode corresponding to every three rows of phosphor dots arranged in the horizontal direction (horizontal direction in the drawing).

As shown in FIG. 2, the inner surface of the back panel (16) is covered with a metal film to form a back electrode (20).

The cathode (3) has an amplitude of ±2V with the center voltage at zero volts.
An alternating current of 100 KHz is applied in the range of , emitting free electrons, while the back electrode (20) is kept at zero volts DC or a slightly higher potential to facilitate the emission of electrons from the surface of the cathode (3). do.

The address electrode substrate (4) has a first address electrode (42) extending in the Y direction (vertical direction) of the XY matrix on one surface of a base (40) formed of glass or ceramic. In addition to forming each row of phosphor dots, on the other surface of the base (40),
The X direction (horizontal direction) of the XY matrix, that is, the first
A second address electrode (44) facing in a direction perpendicular to the address electrode (42) is formed for each row of phosphor dots existing in that direction.

3143 first address electrodes (42) are arranged in parallel, corresponding to the number of phosphor dots lined up in the horizontal direction of the front panel (1), and address signal voltages in the horizontal scanning direction are sequentially applied to these electrodes. is applied.

On the other hand, 1035 second address electrodes (44) are arranged in parallel, corresponding to the number of phosphor dots arranged in the vertical direction.
Address signal voltages in the vertical scanning direction are sequentially applied to these electrodes.

The intersecting position of the picture electrodes (42) and (44) corresponds to each phosphor dot, and at the intersecting position, an aperture (41) penetrating the electrode and the substrate is inserted into the address electrode substrate (4) as shown in FIG. Form over the entire surface.

Lead terminals (43) (45) electrically connected to each address electrode are formed on the outer periphery of both surfaces of the address electrode substrate (4), and a frit glass (45) is formed on the lead terminals (43) (45). 47) Frame glass (12) via (47)
) (46), and a flexible wiring board (not shown) is connected to each lead terminal.

The cathode (3) is connected to the aperture (
41), the intensity of the electron beam emitted from the cathode (3) and focused on the aperture (41) varies depending on the position of the aperture.
Due to the presence of spots, the brightness of the screen is not uniform. However, by providing a grid electrode, the grid electrode (5
) acts as a planar electron emission source, and the cathode (3)
The purpose is to alleviate the above-mentioned problem caused by the linear shape of the luminance, and to average the luminance as much as possible.

The grid electrode (5) has first and second address electrodes (42) (44) formed by forming a large number of through holes in a fine density on the surface of a thin metal plate.
) is provided with a grid surface (50) arranged in a grid pattern in the direction of . When the voltage of the aperture (41) to a specific position on the phosphor screen increases due to the operation of the address electrodes (42) (44), thermionic electrons emitted from the cathode (3) are diffused and attracted to the grid surface (50). , accelerate and pass through the through holes distributed on the grid surface (50).

The grid electrode attracts and sends out thermoelectrons not only from the cathode closest to the aperture, but also from cathodes located far away, so the intensity of the electron beam is stabilized and the brightness of the screen is uniform.

The grid electrode (5) has terminals (51) protruding from both ends, and as shown in FIG. 6 Place it on the edge of the frame glass (21) as shown in Figure 6, and connect the upper and lower frame glasses (46) (21) with the frit glass.
It is attached to the body and stretched under tension into an airtight space.

FIG. 3 shows another embodiment of mounting the grid electrode (5), in which a pair of support stands (55) are provided protruding from the inner surface of the back panel (2) on the sides of the cathode (3). The edge of the grid electrode (5) is placed on the support base (55), a holding glass (56) is placed on top of the edge, frit glass is provided on both sides of the edge of the grid electrode, and the edge of the grid electrode is melted. The edges are fixed onto a support base.

In the embodiment shown in FIG. 4, the support base (5) is connected to the address electrode substrate (
4) The edge of the grid electrode (5) is fixed to the support base (5) by providing it on the lower surface.

Grid electrodes (5) are located on the front and back panels (1) (2)
A combination of metal materials is selected that has a larger coefficient of thermal expansion than the glass that makes up the glass.

For example, panels (1) and (2) are made of silicate glass (82X10
-'/℃) (However, the number in parentheses is the coefficient of thermal expansion.)
In this case, the grid electrode is made of 42-6 alloy (42N
i, 6Cr, remainder Fe) (90X 10-'/
'C), panel is soda glass (90X 10-'/”
In case of C), the grid electrode is made of stainless steel (S
US410), 50%Ni-50%Fe alloy, 26
%Cr-Fe alloy, Fernico alloy (30%Ni-2
5%ω-8%Cr-37%Fe) (all 95~
100×10−'/'C) is selected.

Since the coefficient of thermal expansion of the grid electrode (5) is larger than that of the front and back panels, the display unit is assembled and heated in a furnace to melt the frit glass, and both ends of the grid electrode are connected to the edges between the front and back panels. Once integrated with the edges, when the display unit is subsequently taken out of the oven and cooled to room temperature, the grid electrode (5) is stretched under tension in the airtight space due to the difference in thermal expansion coefficients.

In order to further increase the tension of the grid electrode (5), the grid electrode (5) is assembled using the jig (6) shown in FIGS. 7 and 8 when manufacturing the display unit.

The jig (6) includes a pair of mounting rods (61) arranged in parallel.
It is constructed by a combination of a rectangular frame whose both ends are connected by tension rods (60) (60) and a presser rod (63), and the mounting rod (61) and the presser rod (63) A protrusion (62) is provided on one side of each opposing surface, and a groove (64) is provided on the other side. The tension rod (60) is selected from a suitable material having a coefficient of thermal expansion larger than that of the grid electrode. As shown in FIG. 8, the grid electrode (5) has a slightly large extension (52) on the outside of the grid surface (50) and the terminal (51). When this tensioning allowance (52) is placed between the mounting rod and the holding rod, and both rods (61) and (63) are pressed to fit together, the tensioning allowance (52) is moved by the convex strip (62) into the concave groove (64). It is pushed down and stretched under tension within the frame of the jig.

When manufacturing display panels, grid electrodes (5
) are pre-tensioned and attached to the jig (6), as shown in Fig. ) etc.

A frit glass is interposed between the faces of the assembly to be joined, a part of the frame glass (21) is opened (22), an exhaust pipe (23) is placed, and the frit glass is heated in a furnace until it melts. do. The jig is thermally deformed by heating in the furnace, and at this time, since the coefficient of thermal expansion of the tension rod (60) is larger than that of the grid electrode, the grid electrode is tensed more and more.

The grid electrode is held under tension between the panels (1) and (2) by the melting and subsequent solidification of the frit glass.

After the display unit is integrated and cooled, it is taken out from the furnace, the jig (6) is removed from the grid electrode, the tensioning margin (52) is cut and removed, and the exhaust pipe (23) is removed.
The display unit is then evacuated and sealed to create a vacuum inside the display unit.

FIGS. 9, 10, and 11 show other embodiments of the grid electrode (5), in which the grid electrode (5) is pretensioned and stretched with a jig (6), and then a cut is made. It is separated into a plurality of parallel grid electrode strips (53). Each grid electrode strip (53) is close to each other but is independent from each other without contacting each other, and each has a terminal (54) at its end.

Each grid electrode strip (53) is connected to and regulated by a switching means (7), and the grid voltage is applied only to one grid electrode strip (53) determined by the switching means (7), and to other grid electrode strips (53). No grid voltage is applied to the electrode strip (53). Therefore, the first and second address electrodes (42) (4
4), when one of the horizontally arranged scan electrodes, for example the second electrode (44), is in operation, the ninth
As shown in the figure, the corresponding grid electrode strip (53)
Apply grid voltage only to Other grid electrode strips (
Since no grid voltage acts on 53a) (53b), the cathode (53b) directly below one grid electrode strip (53)
In addition to 3), it can also attract thermionic clouds from a wide range on both sides and emit a strong electron beam. Moreover, since the grid current can be concentrated and applied to one grid electrode strip (53), power consumption is low (the number of grid electrode divisions is n).
In the case of a book, the grid current can be increased n times to intensify the electron beam output and improve the brightness of the image.

In this embodiment, the time during which the grid voltage is applied to a particular grid electrode strip is short, and the energization is switched to the adjacent grid electrode strip (53b) at the next instant. Even if a high grid voltage and current are applied to 53), the amount of heat generated is small and thermal deformation of the grid electrode strips hardly occurs.

FIG. 11 shows an example of a switching means for a plurality of grid electrode strips (53), and shows a flat display unit (
14) of the address electrode protruding from the terminal (42) (
43), a data electrode drive circuit (75) and a scan electrode drive circuit (74) are connected through a flexible printed circuit board as is well known, and the memory, A
A known control circuit (70) having functions such as /D conversion, timing control, and video signal processing processes the video signal and drives each of the drive circuits (74) and (75). A part of the horizontal synchronization signal sent from the control circuit (70) is branched and input to a counter (71) to count the number of horizontal scans. One grid electrode strip (53
) corresponds to m address electrodes (44),
Outputs one pulse every m horizontal scans, and outputs one pulse to the encoder (7
2) outputs a signal specifying a predetermined grid electrode strip (53) to drive the grid drive circuit (73).

The grid drive circuit (73) connects the designated grid electrode strip (53) to the grid voltage source and applies the grid voltage. The number of divisions of the grid electrode is 2
Any number above may be used, and one or three address electrodes (
44), or one grid electrode strip (53) may correspond to each address electrode group.

The present invention has the effect that the grid electrode can be stretched in a tensioned state in a flat display unit with a simple structure, and that the output of the electron beam can be increased by the grid electrode to improve the brightness of the image.

The invention is not limited to the above description and drawings;
It goes without saying that those skilled in the art can make design changes within the scope of the claims, and such changes belong to the technical scope of the present invention.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the assembly status of the flat display, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Figs. 3 and 4 are cross sections of other embodiments of the grid electrode support part. Figure 5 is a perspective view showing how the grid electrode is attached to the glass frame, Figure 6 is a plan view of another embodiment same as above, and Figure 7 is how the jig is used to tension the grid electrode. Figure 8 is a slope view showing the jig covered with grid electrodes.■-■ in Figure 7
9 is an explanatory diagram of the operation of another embodiment of the grid electrode, FIG. 10 is a plan view of the same embodiment of the grid electrode, and FIG. 11 is an embodiment of the embodiment shown in FIGS. 9 and 10. FIG. 12 is a sectional view of a conventional example. (1)...Front panel (10)...Fluorescent screen (2)
... Rear panel (3) ... Cathode (4) ...
Address electrode substrate (40)...Base (41)...
Aperture (42)...First address electrode (44)...Second address electrode (5)...Grid electrode (53)...Grid electrode strip (6)...Jig (
7)...Switching section

Claims (1)

[Claims] [1] Front panel (1) with a fluorescent screen (10) on the back side
and a back panel (2) arranged parallel to the front panel and forming a flat airtight space between the front panel and the front panel;
A plurality of linear filament cathodes (3) arranged in parallel along the inner surface of the back panel; and the cathodes (3).
An address electrode substrate (4) is arranged between the front panel (1) and the phosphor screen (10) and controls the irradiation of electrons to a specific position on the phosphor screen (10), and the address electrode substrate (4) and the cathode (3)
), and a panel-shaped grid electrode (5) having a grid surface (50) arranged with a large number of through holes, the panel-shaped grid electrode (5) is arranged between the front panel ( 1) and back panel (2)
1. A flat display device, characterized in that it is formed of a metal material having a coefficient of thermal expansion larger than that of , and is previously disposed under tension in an airtight space between a front panel and a rear panel. [2] Front panel (1) with fluorescent screen (10) on the back
and a back panel (2) arranged parallel to the front panel and forming a flat airtight space between the front panel and the front panel;
A plurality of linear filament cathodes (3) arranged in parallel along the inner surface of the back panel; and the cathodes (3).
An address electrode substrate (4) is arranged between the front panel (1) and the phosphor screen (10) and controls the irradiation of electrons to a specific position on the phosphor screen (10), and the address electrode substrate (4) and the cathode (3)
) and a panel-shaped grid electrode (5) having a grid surface (50) in which a large number of through holes are arranged.
) is constituted by a plurality of grid electrode strips (53) parallel to each other, and each grid electrode strip (53) has a grid switching means (7) that switches and operates according to the address electrode (44) in operation in the horizontal scanning direction. ) A flat display device characterized in that it is connected to a grid voltage source via a [3] A porous surface (50
) is maintained in a tension state by a jig (6) and placed parallel to the back panel, and an address electrode substrate ( which controls the irradiation of electrons to a specific position on the phosphor screen (10)). 4), the grid electrode (5)
A step of arranging the front panel (1) having a fluorescent screen (10) on the back surface in parallel above the address electrode substrate (4).
A step of arranging them in parallel upwardly, and heating the back panel (2), grid electrode (5), address electrode substrate (4), and front panel (1) assembled by the above steps to integrate their respective peripheral edges. a step of removing the jig (6) from the grid electrode (5) and placing the grid electrode (5) under tension in the airtight space between the front panel (1) and the back panel (2); How to manufacture flat displays by. [4] For a pair of mounting rods (61) (61) arranged in parallel, both ends of each mounting rod (61) (61) are connected by tension rods (60) (60) to form a rectangular frame. A presser rod (63) is arranged opposite to each mounting rod (61), and a projection (62) is provided on one side of the opposing surface of each of the mounting rod (61) and the presser rod (63), and a protrusion (62) is provided on the other side. A concave groove (64) is formed in the mounting rod (61) and the holding rod (63), and the mounting rod (61) and the holding rod (63) are fitted through tensioning margins (52) at both ends of the grid electrode (5), and the tensioning rod (60) ) is formed of a metal material having a coefficient of thermal expansion larger than that of the grid electrode (5) to be stretched.