JPH10275575A - Spacer and image forming apparatus - Google Patents

Abstract

(57) [Summary] [Problem] It is difficult to increase the height and obtain a low-cost spacer. SOLUTION: In a spacer for holding a space between opposing substrates, the height is d, and the length of a vertical side surrounding a shape viewed from the top when the area of a quadrangle that is a quadrangle is the minimum is set as the length. When L1 and the length of the side are L2, L1>
L = L2 for L2, L = L1 for L1 <L2,
When L1 = L2, when L = L1 = L2, d ≦
It satisfies the condition of L and is manufactured by a molding method. When the length of the upper base of the cross-sectional shape is a and the length of the lower base is b, 0
It satisfies the condition of ≦ a ≦ b (except when a = b = 0) and is manufactured by a molding method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer and an image forming apparatus using the spacer.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus using an electron-emitting device, an electron source substrate on which a large number of cold cathode electron-emitting devices are formed and an anode substrate provided with a transparent electrode and a phosphor are opposed in parallel to each other. 2. Description of the Related Art A flat-type electron beam display panel that has been exhausted is known. In such an image forming apparatus, the one using a field emission type electron emitting element is, for example,
I. Brodie, “Advanced techno
logy: flat cold-cathode CR
Ts ", Information Display, 1
/ 89, 17 (1989). Also, those using the surface conduction electron-emitting device, for example,
It is disclosed in U.S. Pat. No. 5,066,883 and the like. A flat-type electron beam display panel can achieve a lighter weight and a larger screen than a cathode ray tube (CRT) display device which is widely used at present, and a flat-type display using liquid crystal. As compared with other flat display panels such as a panel, a plasma display, and an electroluminescent display, an image with higher brightness and higher quality can be provided. FIGS. 49 and 50 show schematic configuration diagrams of a conventional flat-type electron beam display panel as an example of an image forming apparatus using an electron-emitting device. Here, FIG. 50 is a sectional view taken along the line AA ′ in FIG.

The structure of the conventional flat type electron beam display panel shown in FIGS. 49 and 50 will be described.
1 is a rear plate which is an electron source substrate, 102 is a face plate which is an anode substrate, 103 is an outer frame, and these constitute a vacuum envelope. 104 is a glass substrate which is a base of the rear plate, 105 is an electron-emitting device, and 106a and 106b are electrodes for applying a voltage to the electron-emitting device 105. 107a (scanning electrode) and 107b (signal electrode) are electrode wirings, which are connected to the electrodes 106a and 106b, respectively. 10
8 is a glass substrate which is a base of the face plate, 109
Is a transparent electrode, and 110 is a phosphor. Reference numeral 111 denotes a spacer which holds the rear plate 101 and the face plate 102 at a predetermined interval and is arranged as a support member for atmospheric pressure.

In order to form an image on this electron beam display panel, scanning lines 107 arranged in a matrix are used.
a, a predetermined voltage is sequentially applied to the signal wiring 107b to selectively drive a predetermined electron-emitting device 105 located at the intersection of the matrix, and emit the emitted electrons to the phosphor 11
By irradiating 0, a bright point is obtained at a predetermined position. Note that a high voltage is applied to the transparent electrode 109 so that the transparent electrode 109 has a positive potential with respect to the element 105 in order to accelerate the emitted electrons and obtain a bright spot having higher luminance. Here, the applied voltage is a voltage of several hundred V to several tens kV, depending on the performance of the phosphor. Therefore, the rear plate 101 and the face plate 1
02 (more precisely, the wiring 107b and the transparent electrode 109)
Is generally set to about 100 μm to several mm in order to prevent vacuum breakdown (ie, discharge) from occurring due to the applied voltage.

[0005] As the display area of the display panel increases, the rear plate substrate 104 and the face plate substrate 108 need to be thickened in order to suppress the deformation of the substrate due to the difference between the vacuum inside the envelope and the atmospheric pressure outside. Have been.
Increasing the thickness of the substrate not only increases the weight of the display panel, but also causes distortion when viewed from an oblique direction. Therefore, by disposing the spacer 111, the substrate 10
4,108 can reduce the strength load, and can reduce the weight, cost, and size of the screen, so that the advantages of the flat-type electron beam display panel can be fully exhibited.

[0006] The material used for the spacer 111 is to have sufficient atmospheric pressure resistance (compressive strength), and to have heat resistance enough to withstand the heating process in the manufacturing process and the high vacuum forming process. The thermal expansion coefficient of the panel must be matched with that of the panel frame, outer frame, etc.-It must be a high-resistance body (insulator) with a withstand voltage that can withstand high voltage application.-To maintain a high vacuum , A low gas release rate, and a requirement for processing with high dimensional accuracy and excellent mass productivity. Generally, a glass material is used.

[0007] On the other hand, "Advanced technology"
logy: flat cold-cathode CR
Ts "(Information Display 1
/ 89, pp. 17-19) and U.S. Patent No. 5,063,32.
In No. 7, Ivor Brodie discloses a spacer using polyimide. In this method, a photosensitive polyimide is applied to a substrate by a spin method, pre-baked, and then vacuum baked through a photolithography (mask exposure, development, washing) process, and finally applied to the cathode substrate surface. A 100 micron high polyimide spacer is being made. U.S. Pat. No. 5,371,433 can also be cited as an example utilizing photosensitive polyimide.

[0008]

However, when the above-mentioned spacer material is used, there are the following problems.

[0009] General glass materials are relatively good in mechanical strength, thermophysical properties and outgassing properties.
In addition, the material is easy to use as a spacer because of good workability and mass productivity. However, regarding the dielectric strength,
In particular, charging of the surface (probably due to secondary electron emission)
, A creeping discharge is likely to occur, so that a very high voltage cannot be applied, and it is difficult to display with sufficient brightness.

On the other hand, when a spacer is formed from a polyimide resin by photolithography, mechanical strength is inferior to that of a glass material, but it is easy to increase the number of spacers to be arranged, so that atmospheric pressure resistance can be obtained.
Although heat resistance and outgassing characteristics may be slightly inferior to those of glass materials, they can be used in glass envelopes without any problem by performing appropriate annealing treatment or the like. Regarding the electrical properties, the insulation resistance is good and the creepage withstand voltage is high. However, the workability has the following problems.

According to the photolithography process described above,
The height of the polyimide spacer that can be made in one process is at most several to several tens of microns, to make a height of several millimeters,
The process had to be repeated many times.

On the other hand, as described above, the height of the spacer is required to some extent in order to efficiently evacuate the inside of the display to a high vacuum and to prevent discharge. Therefore, repeating the process many times leads to an increase in cost, which has been a problem.

In this step, the spacers may fall or break as d increases, leading to a reduction in the yield of the step.

Further, in order to prevent the yield from decreasing, it is necessary to increase the width of the spacer itself. However, if the width of the spacer is increased, it becomes impossible to produce a high-definition image forming apparatus.

Further, when coating the substrate or the front glass with polyimide, a baking step is always required,
The manufacturing process (order) of the substrate or the front glass is restricted.

If a failure occurs during the step of preparing the polyimide spacer, both the polyimide spacer and the glass substrate have to be discarded, resulting in an increase in cost and waste of resources.

Accordingly, the height of the spacer which can be actually used is at most several hundred microns or less, and the voltage which can be applied to the face plate is limited. For this reason, high-acceleration phosphors with high performance (acceleration voltage of several kV to several tens of kV) used in current CRTs are difficult to use, and low-acceleration phosphors with inferior performance such as luminance and color purity must be used. I had to.

Further, since the spacer forming step is performed on the rear plate or the face plate, a residue of polyimide may remain on the rear plate or the face plate or damage the electron-emitting device during the step. I was worried.

Therefore, in the present invention, compared with the glass material,
Focusing on spacers using resin with poor mechanical strength but excellent dielectric strength and creepage strength, alternative to the photolithography method of resin spacers, height can be formed higher, and low cost suitable for mass production It is an object to provide a simple spacer and an image forming apparatus. At the same time, it is another object of the present invention to provide a spacer and an image forming apparatus which eliminate the complexity of a process in which a large number of spacers are required due to poor mechanical strength.

[0020]

The above object is achieved by the following spacer and image forming apparatus of the present invention.

The spacer according to the first aspect of the present invention is a spacer for maintaining a space between opposing substrates, wherein the height is d, and the area of a square having a rectangular shape surrounding a shape viewed from above is minimized. When the length of the vertical side is L1 and the length of the horizontal side is L2, when L1> L2, L = L
2. L = L1 when L1 <L2, L = L1 = L2 when L1 = L2, and satisfy the condition of d ≦ L and are manufactured by a molding method. It is.

The spacer according to the second aspect of the present invention is a spacer for maintaining a space between opposing substrates, wherein a is 0 ≦≦ a when the length of the upper base is a and the length of the lower base is b. It satisfies the condition of a ≦ b (except when a = b = 0) and is manufactured by a molding method.

According to a third aspect of the present invention, the first or second spacer is made of a polyimide.
Or it consists of polybenzimidazoles (polybenzimidazoles).

The spacers according to the fourth, fifth and sixth aspects of the present invention are characterized in that the third spacer is manufactured by an injection molding method, a compression molding method or a casting method.

A first image forming apparatus according to the present invention is an image forming apparatus having a structure in which a substrate on which a plurality of electron-emitting devices are formed and a substrate on which an image forming member is formed are opposed to each other via a spacer. The spacer is any one of the first to sixth spacers.

The second image forming apparatus of the present invention is characterized in that the electron-emitting device of the first image forming device is a surface conduction electron-emitting device.

According to the present invention, the spacer is self-supporting, can be manufactured without falling down or breaking, can be manufactured, has heat resistance, has a small amount of released gas, has a large gap height, and has strength. This makes it possible to produce a low-cost spacer excellent in mass productivity, and also to improve the performance of a display device using the spacer.

[0028]

FIG. 1 shows an example of the spacer of the present invention.

FIG. 1A shows an L-shaped spacer. Hereinafter, FIG. 1 (B) is a wave type, FIG. 1 (C) is a rectangular wave type, FIG. 1 (D) is a wave type plus rectangular wave type, FIG.
(E) shows a cross type. When the area surrounding the square (rectangular or square) spacer in the plane supported by the spacer is minimized in a state where the spacer is self-standing, the vertical side of the square is defined as L1 and the horizontal side is defined as L2. When the shorter one of L1 and L2 is L (square, ie, L1 = L2, L = L1 = L2), and the height of the spacer is d, this spacer satisfies the following relationship. .

D ≦ L By satisfying this condition, the spacer becomes self-supporting. This condition was determined by the following method. The spacers were prepared by varying the values of L and d of the spacers described above, and indeed, independence and ease of assembling when used for assembling a display panel described later were indicated by 、 and ×. This is the graph of FIG. In FIG. 2, the vertical axis indicates L of the spacer shown above, and the horizontal axis indicates the height of the spacer. The symbol “場合” indicates a case where the display device did not fall down during the assembling work and there was no problem in handling. × indicates a case where the display device has fallen, shifted, or broken during the display device assembling work. From this result, it can be seen that if the condition of d ≦ L is satisfied, the spacer satisfies autonomy.

FIG. 27 shows another example of the spacer of the present invention. FIG. 28 is a diagram in which a spacer having the shape shown in FIG. 27 is applied to an image display device.

FIG. 27A shows a trapezoid type spacer. FIG. 27B shows a triangular type spacer. When the length of the upper base is a and the length of the lower base is b, 0 ≦ a ≦ b (where a = b = 0)
). If the spacer is slightly tapered, it can be easily removed from the mold. Also, when assembling the spacer to the panel, if the cross section is trapezoidal or triangular, there is an advantage that the spacer is less likely to fall down due to vibration during assembly.

The spacer of the present invention is not particularly limited to an image forming apparatus such as a display device, but can be applied to any spacer that maintains a space between opposing substrates. In an image forming apparatus using an electron-emitting device, since the space between the substrates is maintained in a vacuum, the spacer must be capable of withstanding atmospheric pressure, but is not necessarily in a vacuum state.
For example, the spacer of the present invention can be used even when the pressure between the substrates is lower than the atmospheric pressure as in a plasma display. Further, the present invention can be used for an application in which an external force is applied to the substrates even if the pressure between the substrates is not lower than the atmospheric pressure.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. Embodiment 1 FIG. 3 is a perspective view of a display panel used in the present embodiment. As the spacer, a spacer having the shape shown in FIG. 1C was used. In FIG. 3, a part of the panel is cut away to show the internal structure.

In the figure, 2 is a face plate, 2-1 is a glass substrate, 2-2 is a phosphor, 2-3 is an anode electrode,
Is a rear plate, and 6 is a side wall. The face plate 2, the rear plate 5, and the side wall 6 form an airtight container for maintaining the inside of the display panel in a vacuum. When assembling the airtight container, it is necessary to seal the joint of each member to maintain sufficient strength and airtightness,
For example, sealing was achieved by applying frit glass to the joint and baking it in the air or in a nitrogen atmosphere at 400 to 500 degrees Celsius for 10 minutes or more.

A substrate 7 is fixed to the rear plate 5, and N × M electron-emitting devices 3 are formed on the substrate. In the present embodiment, N = 160 and M = 780 (N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. For example, display of a high-definition television is performed. In the intended display device, N =
It is desirable to set the number to 3000, M = 1000 or more. ).

The electron-emitting devices are simply wired by M row-directional wirings (lower wiring 4-2) and N column-directional wirings (upper wiring 4-1). The row wiring (lower wiring 4-
The portion constituted by 2) and the column direction wiring (upper wiring 4-1) is called a multi-electron beam source.

D0x1 to D0xm and D0y1
D0yn and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel to an electric circuit (not shown). D0x1 to D0xm are wirings in the row direction of the multi-electron beam source (lower wiring 4-2), and D0y1 to D0y1.
D0yn is a column-directional wiring (upper wiring 4) of the multi-electron beam source.
-1), Hv is electrically connected to the anode electrode of the face plate. The electron-emitting device 3 of the present embodiment includes:
For example, a surface conduction electron-emitting device described in JP-A-7-45221 was used.
A field-emission electron-emitting device, a MIM-type device, or the like made of a carbon material containing a conical, pyramidal or acicular metal, silicon, or diamond can also be used.

In this embodiment, the substrate 7 of the multi-electron beam source is fixed to the rear plate 5 of the airtight container. However, if the substrate 7 of the multi-electron beam source has a sufficient strength, Alternatively, the substrate 7 of the multi-electron beam source may be used as the rear plate of the airtight container.

FIG. 4A is a schematic sectional view taken along the line AA 'of FIG. 3, and the numbers of the respective parts correspond to those of FIG. The spacer 1 is connected to the upper wiring 4-1 and the face plate 2 via a bonding material (not shown) such as frit glass, and supports the atmospheric pressure received by the face plate 2 and the rear plate 5. 4-1-1 is an upper wiring electrode, and 4-2-1 is a lower wiring electrode.

FIG. 4B is a schematic cross-sectional view taken along line BB ', and the spacer 1 is disposed on the lower wiring 4-2. Reference numeral 1-2 denotes an exhaust hole for efficiently exhausting the gas inside the display device, but may not be provided when assembling the display device in a vacuum.

The connection of the spacer to the face plate 2 or the rear plate 5 can be performed not only by using a bonding material but also by providing a protrusion or a concave portion on the spacer and performing a corresponding process on the plate.
Furthermore, the spacer does not need to be fixed up and down with respect to both plates, and only one may be fixed.

The number of spacers is designed to be sufficient to support the atmospheric pressure in consideration of the strength of the spacers.

Further, a phosphor 2-2 and a metal back (anode electrode) 2-3 are formed on the lower surface of the glass substrate 2-1. Since the present embodiment is a color display device, phosphors of three primary colors of red, green, and blue used in the field of CRT are separately applied to a portion of the phosphor 2-2. The phosphors of each color are separately applied in stripes as shown in FIG. 5A, for example, and a black light absorber 2-4 is provided between the stripes of the phosphors. Black light absorber 2-
The purpose of providing 4 is to prevent the display color from being shifted even if the irradiation position of the electron beam is slightly shifted,
The purpose is to prevent reflection of external light to prevent a decrease in display contrast, and to prevent charge-up of the phosphor by an electron beam when the black light absorber is conductive. Although graphite is used as a main component for the black light absorber 2-4, any other material may be used as long as it is suitable for the above purpose.

The method of applying the phosphors of the three primary colors is not limited to the stripe arrangement shown in FIG. 5A, but may be, for example, a delta arrangement as shown in FIG. Other arrangements may be used.

When a monochrome display panel is produced, a monochromatic phosphor material may be used for the phosphor 2-3-1 and a black light absorber may not necessarily be used.

Further, for the purpose of applying an acceleration voltage and improving the conductivity of the phosphor, the face plate 2 and the phosphor 2-2 are used.
And a transparent electrode (not shown) made of, for example, ITO.

The purpose of providing the metal back 2-3 is to improve the light utilization rate by mirror-reflecting a part of the light emitted from the phosphor 2-2 and to protect the phosphor 2-2 from the collision of negative ions. To act as an electrode for applying an electron beam acceleration voltage, and to act as a conductive path for the excited electrons of the phosphor 2-2. The metal back was formed by forming the phosphor 2-2 on the face plate 2, smoothing the surface of the phosphor, and vacuum-depositing aluminum thereon. When a phosphor material for exciting low-acceleration electron beams is used for the phosphor 2-2, the metal back may not be used in some cases.

The above-mentioned phosphor, phosphor and metal back, phosphor, metal back and transparent electrode correspond to the image forming member.

In order to evacuate the inside of the hermetic container, after the hermetic container is assembled, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is evacuated to a degree of vacuum of about 10 ^-7 [Torr]. Exhaust until After that, the exhaust pipe is sealed,
In order to maintain the degree of vacuum in the airtight container, a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after sealing. The getter film is, for example, a film formed by heating and depositing a getter material containing Ba as a main component by a heater or high-frequency heating, and the inside of the hermetic container is 1 × 10 ⁻⁵ or 1 × by the adsorption action of the getter film.
The degree of vacuum is maintained at about 10 ^-7 [Torr].

The basic configuration and manufacturing method of the display panel according to the embodiment of the present invention have been described above.

Hereinafter, the spacer used in the present embodiment will be described.

The spacer 1 made by injection molding is shown in FIG.
(A) and its modification is shown in FIG. The material used was polyimide (PI: trade name: AURUM / Mitsui Toatsu Chemical Co., Ltd.). Further, PEEK resin is used as a binder for smoothly performing injection molding. In FIG. 6A, the spacer 1 is composed of a rib 1-1, and the rib is designed so as to sandwich 10.times.10 electron-emitting devices. The size of the opening is 4.6 × 6.
9 mm. The width of the rib (W ₂ ) is 20
0 μm, the thinner (W ₁ ) is 150 μm, and the height (d) is 1 mm. Further, as shown in FIG. 6B, a plurality of the spacers can be connected by ribs 1-3 to improve the handling at the time of assembly. Further in Figure 1
-2 is an opening for improving the conductance when a vacuum is applied to the inside of the panel. The opening can be easily formed on the wall surface of the rib only after the spacer can be formed by injection molding. It is.

FIG. 7 is a view showing an actual horizontal injection molding machine, in which 9 is a hopper, 10 is a plunger, 11 is a material, and a polyimide, a binder,
Consists of plasticizers, lubricants and auxiliaries. 12 is Topy Doe, 1
3 is a heater, 14 is a heating cylinder, 15 is a nozzle,
Reference numeral 16 denotes a sprue, and 17 denotes a mold. In such a configuration, the material 11 in the hopper 9 is heated and melted in the heating cylinder 14 and injected into the mold 17 closed by the plunger 10 to be molded. The mold 17 is constantly cooled, and the material 11 in the mold 17 is cooled and solidified.

More specifically, the heating cylinder 14 is required to have a low local heating and a uniform temperature while the material 11 passes therethrough, and to have a high pressure (0.75 ton / cm). ² or more).

In addition, since polyimide is a poor conductor of heat, in order to heat a large amount of material uniformly in a short time, it is necessary to narrow a passage and speed up heat conduction. In this sense, Topy Doe 12 has been devised. The torpedo 12 has a function of uniformly heating the molding material 11 by a torpedo type device mounted inside the heating cylinder 14.

Furthermore, the nozzle is an important part in terms of pressure and temperature. It is essential to avoid pressure losses in the nozzle, and the material 11 must be kept at a uniform temperature in this region.

As shown in FIG. 8A, the polyimide injected from the nozzle into the split mold 17 through the sprue is injected into the injection hole 21-1 of the injection plate 21 shown in FIG. And is guided to the cavity 20. The injection hole 21-1 has a diameter of 200 to 300 μm at the bottom and 50 at the top.
It has a tapered shape of about 100 μm. At this time, the injection plate 21 is sucked by an air hole (not shown) inside the arm 19 and is fixed to the upper portion of the cavity. The arm 18 is an arm for spacer ejection.

Next, after the polyimide in the mold is cooled and cured, as shown in FIG.
9 descends from above and removes the molded article 1 from the cavity 20. Then, as shown in FIG.
8 descends further, and the molded article 1
And the spacer 1 is completed.

Finally, the suction inside the arm 19 is stopped, and the spacer is recovered. The spacer manufactured through such a process is shown in FIG. Here, a diagram in which three spacers are simultaneously formed is shown for easy understanding.

By performing such a manufacturing method by injection molding, the ribs of the spacer are thin, and high-profile ones can be easily mass-produced. Further, conventionally, the base portions of the ribs were removed one by one by a cutting process. However, in a series of steps for removing the product from the split mold, the separation can be performed. As a result, there is an effect that the process can be shortened and the manufacturing cost can be reduced. In addition, by using the self-supporting spacer manufactured by such a method in a display device using a cold cathode type electron-emitting device such as a surface conduction type electron-emitting device, handling becomes easier and assembly performance is significantly improved. The effect of doing it also comes out. As a result, there is an effect that the process can be shortened and the manufacturing cost can be reduced.

As a material for the spacer, polybenzimidazole (PBI: trade name Celazole T)
F-60V / Hoechst Industry Co., Ltd.) may be used. In this case, the thermal decomposition temperature is 314 ° C., which is higher than that of polyimide, and there is also an effect that heat resistance is improved.

Further, the release gas rate of polyimide or polybenzimidazole in vacuum is 10 ^-7 torr.
It is preferably used because it is very small at 1 / cm ² sec or less and has a good withstand voltage, which has the effect of extending the life of the display device. (Embodiment 2) In the present embodiment, the manufacturing method and the shape of the spacer of Embodiment 1 are changed.

FIGS. 11 to 16 show a method of forming a spacer by a compression molding method. This is a method in which a granule or powder material is placed in a mold and subjected to pressure and heat to mold.
The material is polybenzimidazole (PBI: trade name Ce)
lazole / Hoechst Industry Co., Ltd.) having a particle size of 30 μm. As a material, polyimide (PI: VESPEL / Dupont Co., Ltd.) having heat resistance and a small amount of released gas may be used.

In FIG. 11, 17 is a mold and 22 is a shoe, which is a device for pouring a material into the mold, from which polybenzimidazole as a material is sent to the mold. Numeral 10 is a plunger for pressurizing the material, and 23 is a device for sucking the completed spacer, and the inside thereof can be made negative pressure by a pump (not shown). Reference numeral 24 denotes a mesh for supporting the sucked spacer.

In such a configuration, first, the shoe 2
From 2, polybenzimidazole is supplied to the mold 17. Next, as shown in FIG. 12, after the shoe 22 returns to the home position, the plunger 10 descends and starts pressurizing. The pressing force at this time is 1000 kgf
/ Cm ² or more. Further, as shown in FIG.
With the plunger 10 pressurized, the heater 13 rises from the direction of the arrow and starts heating. The temperature at this time is about 425 ° C., which is the glass transition point of polybenzimidazole, and the time is 5 to 10 hours.

Next, as shown in FIG. 14, at the same time as the heater 13 descends in the direction of the arrow, the suction nozzle 23 moves. Then, as shown in FIG. 15, the inside of the suction nozzle 23 becomes a negative pressure due to the suction of the motor (not shown), and the spacer 1 is sucked upward. afterwards,
The sucked up spacer 1 is held by the mesh 24. Finally, it is collected on the tray 25 shown in FIG. The shape of the spacer 1 will be described later.

By performing such a manufacturing method by compression molding, a large number of high-profile spacers having thin ribs can be easily produced. As a result, there is an effect that the process can be shortened and the manufacturing cost can be reduced. Furthermore, according to this method, compared to injection molding,
Since there is no binder, there is no gas released from the binder at the time of high vacuum, and the effect that the life of the display device is prolonged also occurs. It also has heat resistance, and has a heat deformation temperature of 360 ° C., which can withstand up to 480 ° C. in an instant, and has an effect that it can sufficiently withstand a baking process of a display device. Further, the secondary electron emission efficiency σm is 1.9, which is slightly smaller than 2.1 of soda lime (blue plate) conventionally used for the spacer. This indicates that it is difficult to charge up when electrons collide with the spacer, which is also advantageous from this point.

On the other hand, the strength is inferior to the soda lime spacer, but this can be dealt with by increasing the number of spacers. Further, if the shape of the spacer is made into an “L-shape” as shown in FIG. 1 (A) or a “cross-shaped” as shown in FIG. 1 (E), the number of spacers can be further reduced. It is possible to make the number less than or equal to that of the spacer. In addition, handling is easier than glass spacers, and benefits are more apparent when considering assembly costs.

17 to 22, a direct forming method will be described as a more advanced molding method than the compression molding method. This is intended to improve the efficiency of the process by separating the pressurizing step and the heating step in the above-mentioned compression molding method. 17 to 23 are pressurizing steps, which can be performed at room temperature.

The polybenzimidazole powder used at this time was prepared by spraying a DMAc solvent in which 12% by weight of polybenzimidazole was melted in a water mist and precipitated. Polybenzimidazole has a particle size of 30 μm and is impregnated with 10% of DMAc.

As shown in FIG. 17 to FIG.
Pressure was applied at a pressure of kpsi to form the shape of the spacer 1. All of these steps can be performed in a room temperature environment.
As shown in FIG. 23, the spacer 1 manufactured in the above process
Is designed to surround 10 × 10 electron-emitting devices, and the size of the opening is 4.6 × 6.9 m.
m. The larger the width of the rib is, W ₂ = 200 μm
m, W ₁ = 150 μm for the thinner _one , and d = 1 mm for the height. 17 to 22 correspond to the steps shown in FIG.
16 are the same as those in FIGS. 1 to 16 except that there is no heating step by the heater 13.

The spacer 1 thus produced is connected to the spacer 1 shown in FIG.
And pressurized and heated at the same time. 10 is a plunger, 26 is a nut, 27 is a pressurizing plate, 31 is a lid, 28 is a pressurizing / heating container having an inner diameter of 90 mm,
It has an outer diameter of 180 mm and a height of 300 mm. 29 is a bolt, 1 is a spacer, 30 is graphite, and 32 is a bottom plate. In such a configuration, first, the spacer 1 is preheated at 200 ° C. to evaporate water. Next, 1-3 k is applied to the pressing plate 27 via the plunger 10.
After applying a pressure of psi for 15 minutes, heat at 425-500 ° C. for several hours at a pressure of 10 kpsi. Since the graphite 30 is contained in the pressurizing / heating container 28, uniform pressure and temperature are applied to the spacer from all directions. Thereafter, the pressurizing / heating container 28 is cooled and the spacer is taken out.

With such a direct forming method,
If the spacer is made, the pressurizing step and the heating step can be separated, so that there is an advantage that a large amount of the spacers 1 can be simultaneously pressed and heated at room temperature, and then a large amount can be simultaneously heated. Further, the ribs of the spacer 1 are thin, and a high object can be easily mass-produced. In addition, by using the self-supporting spacer manufactured by such a method in a display device using a cold cathode type electron-emitting device such as a surface conduction type electron-emitting device, handling becomes easier and assembly performance is significantly improved. The effect of doing it also comes out. As a result, there is an effect that the process can be shortened and the manufacturing cost can be reduced. Further, according to this method, since there is no binder as compared with injection molding, there is no gas released from the binder at the time of high vacuum, and the effect of extending the life of the display device is also produced. It also has heat resistance, and has a heat deformation temperature of 435 ° C., and can withstand up to 760 ° C. at an instant, and has an effect of sufficiently withstanding a baking process of a display device. (Embodiment 3) This embodiment is also a modification of the manufacturing method and the shape of the spacer of Embodiment 1.

FIG. 25 is a view showing a state of the casting method, in which a polyimide varnish (trade name: pyre-ML / IS.
T [stock]), and a cock 34 for controlling the flow of the polyimide varnish into the mold 17. In such a configuration, the cock 34 is opened, and the polyimide varnish is injected from the tank 33 into the mold 17. The injected polyimide varnish enters the cavity 20 through the injection hole 21-1 (not shown) of the injection plate 21. Next, as shown in FIG. 26A, the inside of the processing chamber 35 is evacuated to a negative pressure by a vacuum pump 36. By doing so, air bubbles in the polyimide varnish are removed, and at the same time, every corner of the cavity 20 is filled with the polyimide varnish. After the air bubbles are sufficiently removed in this manner, the heater 13 is
By heating at 30 ° C. for 30 minutes or more, the spacer 1 is cured.

Next, after the polyimide varnish in the mold is cooled and hardened, as shown in FIG.
8 and 19 come up from below and remove the molded article 1 from the cavity 20. Then, as shown in FIG. 26 (C), when the arm 18 is further raised, the molded product 1 is cut off by the injection plate 21, and the varnish spacer 1 is completed.

Finally, the suction inside the arm 19 is stopped, and the spacer is recovered. For example, the size of the spacer manufactured through such a process has a rib width of 50 μm, a rib height of 1 mm, a vertical pitch of the rib of 4.6 mm, and a horizontal pitch of 9.6 mm. As shown in the figure, a cross-shaped spacer can be obtained.

By performing such a manufacturing method by the casting method, the ribs of the spacer are thinner and the height of the spacer is easily produced in large quantities. In addition, the polyimide varnish has a heat deformation temperature of 400 ° C., and has an effect of sufficiently withstanding a temperature heated in a process of manufacturing a display device. Furthermore, conventionally, the base part of each rib was removed one by one by cutting, but in a series of steps of removing the product from the split mold,
It became possible to separate. In addition, by using the self-supporting spacer manufactured by this method for display devices using cold cathode type electron-emitting devices such as surface conduction type electron-emitting devices, handling becomes easier and assembly performance is significantly improved. The effect of doing it also comes out. As a result, there is an effect that the process can be shortened and the manufacturing cost can be reduced.

As a material for the spacer, polybenzimidazole varnish (trade name: PBI MR Solu)
Tion / Hoechst Industry [Ltd.]) may be used. In this case, the thermal decomposition temperature is 580 ° C., which is higher than that of polyimide, and there is also an effect that heat resistance is improved.

Further, the outgassing rate of polyimide varnish or polybenzimidazole varnish in vacuum is 1
It was very small at 0 ^-7 torr / cm ² sec or less, and an effect of extending the life of the display device was also recognized. (Embodiment 4) FIG. 28 is a perspective view of a display panel used in the present embodiment, using a spacer having the shape shown in FIG. Also, the panel is partially cut away to show the internal structure. Since the configuration of the panel except for the shape of the spacer shown in FIG. 28 is the same as that shown in FIG. 3 of the first embodiment, the same components are denoted by the same reference numerals and redundant description will be omitted. Also, the manufacturing method of each constituent member is the same as that of the first embodiment, and thus the duplicated description is omitted. FIG.
1 'of 8 shows a spacer.

FIG. 29A is a schematic sectional view taken along the line AA 'of FIG. The spacer 1 'is connected to the upper wiring 4-1 and the face plate 2 via a bonding material (not shown) such as frit glass, and the face plate 2 and the rear plate 5 are connected.
Supports the atmospheric pressure it receives. 4-1-1 is an upper wiring electrode. FIG. 29B is a schematic cross-sectional view taken along the line BB 'of FIG. 28, and the spacer 1' is disposed on the lower wiring 4-1.

The spacer used in this embodiment can be manufactured using the same apparatus, manufacturing method, and spacer material as those described in Embodiments 1 to 3 except that the shape of the spacer is different. Here, the drawings relating to the manufacturing apparatus and the manufacturing method are shown, and redundant description is omitted.

FIG. 30 is a view showing an actual horizontal injection molding machine, FIG. 31 is a view showing an injection molding process, FIG. 32 is a view showing a manufactured spacer, and FIG. 33 is a view showing an injection plate. The spacer material is guided to the cavity 20 through the injection hole 21-1 of the injection plate 21 in FIG. The injection hole 21-1 is tapered with a diameter of 200 to 300 μm at the bottom and 50 to 100 μm at the top.

FIGS. 34 to 39 show a compression molding method, FIGS. 40 to 46 show a direct homing method, and FIGS. 47 and 48 show an injection mold method.

[0085]

As described above, by using the spacer of the present invention, the spacer can stand alone, can be manufactured without falling down or bend, has heat resistance, and has a reduced amount of released gas. It is possible to produce spacers that are small, have a large gap height, are strong, have excellent mass productivity, and are inexpensive.

In particular, the use of the spacer of the present invention in an image forming apparatus has the following effects.

1) As a spacer material: Since polyimide and polybenzimidazole are used as the material, heat resistance can be obtained, so that the material can sufficiently withstand the frit step and the baking step.

The release gas rate of polyimide or polybenzimidazole in vacuum is 10 ^-7 torr / c
It was very small at m ² sec or less, and an effect of extending the life of the display device was also recognized.

2) As a manufacturing method, by performing a manufacturing method by a molding method, a large amount of thin and high spacers can be easily produced at a low cost including a demolding step. .

3) As a display device As a display device, the self-supporting spacer manufactured by such a method is used for a display device using a cold cathode type electron-emitting device such as a surface conduction type electron-emitting device. And the effect that the assembly performance is remarkably improved. As a result, there is an effect that the process can be shortened and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 shows L and d of a self-supporting spacer according to Embodiment 1 of the present invention.
FIG.

FIG. 2 is a graph showing a relationship between L and d according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a display device according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of the display device according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration of a phosphor according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration of a spacer according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating the injection molding apparatus according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating the injection molding apparatus according to the first embodiment of the present invention.

FIG. 9 is a view for explaining the injection molding apparatus according to the first embodiment of the present invention.

FIG. 10 is a view for explaining the injection molding apparatus according to the first embodiment of the present invention.

FIG. 11 is a sectional view illustrating a compression molding method according to a second embodiment of the present invention.

FIG. 12 is a cross-sectional view illustrating a compression molding method according to a second embodiment of the present invention.

FIG. 13 is a sectional view illustrating a compression molding method according to a second embodiment of the present invention.

FIG. 14 is a sectional view illustrating a compression molding method according to a second embodiment of the present invention.

FIG. 15 is a sectional view illustrating a compression molding method according to a second embodiment of the present invention.

FIG. 16 is a sectional view showing a compression molding method according to a second embodiment of the present invention.

FIG. 17 is a sectional view illustrating a direct forming method according to a second embodiment of the present invention.

FIG. 18 is a sectional view illustrating a direct forming method according to a second embodiment of the present invention.

FIG. 19 is a sectional view illustrating a direct forming method according to a second embodiment of the present invention.

FIG. 20 is a sectional view showing a direct forming method according to a second embodiment of the present invention.

FIG. 21 is a cross-sectional view illustrating a direct forming method according to a second embodiment of the present invention.

FIG. 22 is a sectional view illustrating a direct forming method according to a second embodiment of the present invention.

FIG. 23 is a view showing a spacer manufactured by the direct forming method according to the second embodiment of the present invention.

FIG. 24 is a diagram illustrating an apparatus used for a direct forming method according to a second embodiment of the present invention.

FIG. 25 is a sectional view showing a casting method according to the third embodiment of the present invention.

FIG. 26 is a sectional view showing a casting method according to the third embodiment of the present invention.

FIG. 27 is a perspective view showing a spacer according to Embodiment 4 of the present invention.

FIG. 28 is a perspective view illustrating a display device according to a fourth embodiment of the present invention.

FIG. 29 is a cross-sectional view illustrating a configuration of a display device according to a fourth embodiment of the present invention.

FIG. 30 is a sectional view showing an injection molding apparatus according to a fourth embodiment of the present invention.

FIG. 31 is a sectional view showing an injection molding apparatus according to Embodiment 4 of the present invention.

FIG. 32 is a view showing a spacer of the present invention.

FIG. 33 is a view illustrating an injection molding apparatus according to a fourth embodiment of the present invention.

FIG. 34 is a cross-sectional view illustrating a compression molding method according to Embodiment 4 of the present invention.

FIG. 35 is a cross-sectional view showing a compression molding method according to Embodiment 4 of the present invention.

FIG. 36 is a sectional view showing a compression molding method according to a fourth embodiment of the present invention.

FIG. 37 is a cross-sectional view illustrating a compression molding method according to Embodiment 4 of the present invention.

FIG. 38 is a cross-sectional view showing a compression molding method according to Embodiment 4 of the present invention.

FIG. 39 is a cross-sectional view showing a compression molding method according to Embodiment 4 of the present invention.

FIG. 40 is a cross-sectional view showing a direct forming method according to the second embodiment of the present invention.

FIG. 41 is a cross-sectional view showing a direct forming method according to the second embodiment of the present invention.

FIG. 42 is a cross-sectional view showing the direct forming method according to the second embodiment of the present invention.

FIG. 43 is a cross-sectional view showing a direct forming method according to the second embodiment of the present invention.

FIG. 44 is a cross-sectional view showing a direct forming method according to the second embodiment of the present invention.

FIG. 45 is a cross-sectional view showing the direct forming method according to the second embodiment of the present invention.

FIG. 46 is a diagram showing an apparatus used for the direct forming method according to the second embodiment of the present invention.

FIG. 47 is a sectional view showing a casting method according to the third embodiment of the present invention.

FIG. 48 is a sectional view showing a casting method according to the third embodiment of the present invention.

FIG. 49 is a diagram illustrating a configuration of a conventional display device.

FIG. 50 is a diagram showing a configuration of a display device of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spacer 2 Face plate 3 Surface conduction type electron-emitting device 5 Rear plate 6 Side wall 7 Substrate 9 Hopper 10 Plunger 11 Material 12 Topido 13 Heater 14 Cylinder 15 Nozzle 16 Sprue 17 Mold 18 and 19 Arm 20 Cavity 21 Injection plate 22 Shoe 23 suction nozzle 24 mesh 25 tray 27 pressurizing plate 28 pressurizing / heating container 30 graphite 31 lid 33 material tank 35 chamber 36 vacuum pump

Claims (8)

[Claims] 1. A spacer for maintaining a space between opposing substrates, wherein a height is d, and a length of a vertical side surrounding a shape viewed from the top thereof when a square of a square having a right angle is a minimum. To L
1, when the length of the horizontal side is L2, L = L2 when L1> L2, and L =
When L1 and L1 = L2, when L = L1 = L2, the spacer satisfies the condition of d ≦ L and is manufactured by a molding method. 2. A spacer for maintaining an interval between opposing substrates, wherein the length of the upper base of the sectional shape is a, and the length of the lower base is b, 0 ≦ a ≦ b (where a = b = 0), and manufactured by a molding method. 3. The spacer according to claim 1, wherein the spacer is made of polyimide or polybenzimidazole. 4. The spacer according to claim 3, wherein the spacer is manufactured by an injection molding method. 5. The spacer according to claim 3, wherein the spacer is manufactured by a compression molding method. 6. The spacer according to claim 3, wherein the spacer is manufactured by a casting method. 7. An image forming apparatus having a structure in which a substrate on which a plurality of electron-emitting devices are formed and a substrate on which an image forming member is formed are opposed to each other with a spacer interposed therebetween. An image forming apparatus, comprising the spacer according to any one of the above. 8. The image forming apparatus according to claim 7, wherein said electron-emitting device is a surface conduction electron-emitting device.