JP4684925B2 - Field emission display - Google Patents

Description

The present invention is provided between the anode electrode and the cathode electrode, it relates to a field emission display equipment to the control electrode or the like is provided with a shielding electrode plate to prevent the destruction caused by discharge between the electrodes.

  In general, a field emission display includes a cathode substrate, a cathode electrode formed on the cathode substrate, an insulating layer formed on the cathode substrate and the cathode electrode, and a control formed on the insulating layer. An electrode, an emitter layer formed in the opening formed through the control electrode and the insulating layer, exposed at the bottom of the opening, and formed on the cathode electrode; and disposed in front of the control electrode A known anode substrate and an anode electrode and a phosphor formed on the surface of the anode substrate on the control electrode side are known (see Patent Document 1).

  In this type of field emission display device, a shielding electrode plate having an electron passage hole is further disposed between the control electrode and the anode electrode, and an electron beam flows from the emitter layer to the phosphor through the electron passage hole. The thing is known (refer patent document 2).

  In addition, there is also known a method in which a plate-like member is used as a shielding electrode plate and a method for simplifying the process is formed by forming it independently of the emitter structure on the cathode substrate (see Patent Document 3).

US Pat. No. 4,857,799 (see FIGS. 2 and 3) JP 7-29484 A Japanese Patent Laid-Open No. 9-274845

Constructing the shielding electrode plate with a member made of a metal plate has an advantage that the cathode substrate process can be simplified.
Furthermore, when an unexpected discharge occurs between the anode electrode and the cathode electrode to which a high voltage of about 5 kV to 10 kV is normally applied, the shielding electrode destroys the fine structure such as the electron source and the control electrode. It can be expected to work to prevent this.
That is, since the plate-shaped shielding electrode plate has a low resistance value and a large heat capacity, there is no risk of being easily evaporated and deformed unlike a thin film electrode.

  However, in this field emission display device, the insulation between the shield electrode plate and the control substrate is made by securing a space, but it is necessary to ensure the space distance and ensure the insulation. There was a problem that it was difficult.

This invention has been made and an object of the invention is to solve the problems described above, obtaining the field emission display equipment which can reliably ensure the insulation between the control board and the shielding electrode plate It is for the purpose.

A field emission display device according to the present invention includes a cathode substrate, a plurality of cathode electrodes formed on a surface of the cathode substrate, an emitter layer formed on the cathode electrode,
A plurality of control electrodes formed through an insulating layer on the cathode substrate and having openings formed in a portion facing the emitter layer; an anode substrate disposed facing the cathode substrate;
The phosphor formed on the surface of the anode substrate on the cathode substrate side, the anode electrode formed on the surface of the phosphor, the control electrode, and the anode electrode are disposed between the emitter layer and the emitter substrate. In a field emission display device including a shielding electrode plate formed with a plurality of electron passage holes through which electrons passing through the opening and going to the phosphor pass,
Wherein the shielding electrode plate, at least on the excluding the anode electrode side and the control electric pole surface, the entire surface is formed a dielectric layer which is fixed by an adhesive in surface contact,
A plurality of holes are formed in the entire outer peripheral area of the shielding electrode plate that does not face the emitter layer.
The field emission display device according to the present invention includes a cathode substrate, a plurality of cathode electrodes formed on the surface of the cathode substrate, an emitter layer formed on the cathode electrode, and an insulation on the cathode substrate. A plurality of control electrodes formed through a layer and having openings formed in a portion facing the emitter layer, an anode substrate disposed facing the cathode substrate,
The phosphor formed on the surface of the anode substrate on the cathode substrate side, the anode electrode formed on the surface of the phosphor, the control electrode, and the anode electrode are disposed between the emitter layer and the emitter substrate. In a field emission display device including a shielding electrode plate formed with a plurality of electron passage holes through which electrons passing through the opening and going to the phosphor pass,
In the shielding electrode plate, a dielectric layer is formed at least on the surface on the control electrode surface side excluding the anode electrode side,
In addition, the insulating layer is provided with a rib whose tip surface is bonded to the dielectric layer with an adhesive.
A plurality of holes are formed in the entire outer peripheral area of the shielding electrode plate that does not face the emitter layer.

  According to the field emission display device of the present invention, it is possible to reliably ensure insulation between the shield electrode plate and the control substrate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent members and parts will be described with the same reference numerals.
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a main part of the field emission display device according to the first embodiment. The field emission display device is fixed to the cathode substrate 1 and the cathode substrate 1 using an adhesive (not shown). The emitter structure 2, the shielding electrode structure 3, the light emitter structure 5, and the anode substrate 4 are provided.
The emitter structure 2 includes a plurality of cathode electrodes 6 formed on the cathode substrate 1 so as to be spaced apart in parallel, and an emitter layer (electron emitting material layer) 7 formed on the cathode electrode 6 so as to be spaced apart from each other in parallel. The plurality of insulating layers 10 and the control electrode 8 formed on the surface of the insulating layer 10 are provided. In the control electrode 8, an opening 9 a is formed in the upper facing portion of the emitter layer 7.
An insulating layer 10 is provided on both edges of the cathode substrate 1 and the cathode electrode 6, and a control electrode 8 is provided on the insulating layer 10. An emitter layer 7 is provided on the exposed cathode electrode 6 at the bottom of the openings 9 a and 9 b that penetrate the control electrode 8 and the insulating layer 10.
The cathode electrode 6 and the control electrode 8 have a linear strip shape and are arranged so as to be orthogonal to each other. A plurality of openings 9a of the control electrode 8 are formed in each control electrode 8 at equal intervals.
FIG. 2 is a plan view showing the positional relationship between the cathode electrode 6 and the control electrode 8.
In FIG. 2, the insulating layer 10 is omitted. Since the unit of driving is the intersection of the cathode electrode 6 and the control electrode 8, there may be a plurality of openings in this intersection. In this case, the openings in the same intersection are driven simultaneously.

The shield electrode structure 3 includes a shield electrode plate 12 having an electron passage hole 11 through which an electron beam emitted from the emitter layer 7 through the opening 9a of the control electrode 8 and radiated toward the light emitter structure 5 passes. A dielectric layer 13 fixed to the surface of the shielding electrode plate 12 on the control electrode 8 side using an adhesive (not shown) is provided. The dielectric layer 13 is not formed on the anode electrode 4 side of the shielding electrode plate 12.
The entire surface of the dielectric layer 13 and the control electrode 8 are in surface contact and fixed by an adhesive, and the dielectric layer 13 ensures insulation between the shield electrode plate 12 and the control electrode 8.
Further, a part of the inner wall surface of the electron passage hole 11 on the emitter structure 2 side is covered with a dielectric layer 13, which is caused by scattering of the emitter material between the control electrode 8 and the shielding electrode plate 12 or the emitter layer. 7 and the shielding electrode plate 12 have an effect of reducing the risk of occurrence of a short circuit.

  The light emitter structure 5 includes a phosphor 14 and a black matrix 15 provided on the surface of the anode substrate 4 on the cathode substrate 1 side, and an anode electrode 16 made of aluminum or the like covering the upper surface thereof.

The space between the cathode substrate 1 and the anode substrate 4 is evacuated and maintained at a vacuum lower than 1 × 10 ⁻⁴ Pa, for example. In order to ensure long-term operational stability, getters are often placed inside.

Next, the operation of the field emission display device having the above configuration will be described.
When the control electrode 8 is used as a scanning line and the potential is lowered at the time of selection and the cathode electrode 1 is used as a data line and a light is emitted to the selected scanning line, a positive voltage is applied and electrons are emitted from the emitter layer 7 by the tunnel effect. Pull out.
When light is not emitted, the potential may be lower than that necessary for electron emission.
The extracted electrons do not always go straight in the vertical direction of the cathode substrate 1 but also spread in the radiation direction, so that the trajectory is slightly corrected by the shielding electrode plate 12 and goes almost straight toward the anode substrate 4. A positive high voltage is applied to the anode electrode 16, the emitted electrons are accelerated and collide with the phosphor 14, and the phosphor 14 is excited to emit light. The anode electrode 16 also serves to reflect light emitted from the phosphor 14 toward the cathode substrate 1 side to the anode substrate 4 side (display surface side).
The shield electrode plate 12 has an action of protecting the emitter structure 2 such as the emitter layer 7 from collision of positive ions due to a high voltage applied to the anode electrode 16 and vacuum discharge. The control electrode 8 functions as an extraction electrode (gate electrode) for emitting (extracting) electrons from the emitter layer 7.

The field emission display device having the above-described configuration has the following effects.
I. Since the dielectric layer 13 provided on the entire surface of the shielding electrode plate 12 on the control electrode 8 side is directly fixed on the control electrode 8 of the emitter structure 2 on the cathode substrate 1 by full-surface contact, the emitter structure 2 is surely provided. While securing the insulation between the shield electrode plate 12 and the shielding electrode plate 12, it is possible to secure a wide bonding area and obtain a strong structure. Therefore, for example, the shielding electrode plate 12 does not vibrate due to the driving voltage, which may occur when the electrode is partially fixed.
Further, by forming the dielectric layer 13 on the shield electrode plate 12, warpage deformation of the shield electrode plate 12 itself is suppressed.
Further, by forming the dielectric layer 13 on the shield electrode plate 12, the strength of the shield electrode plate 12 is remarkably reinforced, and the deformation amount due to handling until the alignment (alignment) step with the cathode substrate 1 is reduced. Can be made.
B. Since the dielectric layer 13 is not formed on the anode substrate 4 side of the shielding electrode plate 12, a part of the electron beam collides with the shielding electrode plate 12 and is directly emitted to the outside through the shielding electrode plate 12. It can be prevented that the electrode plate 12 is charged up (charged) and the trajectory of the electron beam drifts.
Even if a vacuum discharge occurs between the shield electrode plate 12 and the anode electrode 16 on the anode substrate 4, the discharge current flows directly through the shield electrode plate 12 to the outside.

  As a specific configuration, the cathode electrode 6 is made of a metal film such as Ag, Cr, Al, Mo, Ag—Pd, Al—Nd, or Ti, or an oxide conductor film such as ITO or ZnO. In order to obtain durability, these materials are appropriately combined to form a multilayer. In particular, when a carbon material having a fine structure such as carbon nanotube (CNT), carbon nanofiber, carbon nanowall, or graphite nanofiber is used for the emitter layer 7, Ti or ITO is used from the viewpoint of electrical resistance, adhesion, and heat resistance. Is suitable. Each film is generally a vapor-deposited film, but it may be formed by pasting fine particles and coating them by a method such as printing. In either case, a pattern is formed by performing exposure and development using a resist after film formation.

As an example of the laminated film of the cathode electrode 6, an underlayer of Mo, Ti or Cr is formed on a glass substrate constituting the cathode substrate 1, and Ag, Ag—Pd, Al, Al—Nd is formed thereon. Are stacked in a thickness of 1000 to 10,000 mm, and a layer of 100 to 1000 mm of the same material or TIN as the underlayer is formed. Further, in order to improve the adhesion with the carbon-based emitter, 1000 to 3000 mm of ITO is laminated. In particular, a laminated film using Al—Nd does not increase in electrical resistance even when fired at a high temperature of 500 ° C. in the atmosphere.
The total thickness of the laminated film should be an upper limit of 1 to 2 μm in consideration of the unevenness of the insulating layer 10 on the cathode substrate 1. The width of the cathode electrode 6 depends on the display pixel size, but when used as a single-plate display device, the range of 30 to 300 μm is suitable for practical use, and the distance between adjacent cathode electrodes 6 is also the capacitance or From the viewpoint of migration, it is about the same as the width or preferably 100 μm or more.

For example, the emitter layer 7 may be formed by patterning by screen printing or other printing methods using a kneaded carbon emitter material in a base form, or by vapor phase growth by CVD using Fe or Mo as a catalyst. .
For the insulating layer 10, a method using a glass paste in which a ceramic fine particle filler and a photosensitive material, a solvent, a binder resin, etc. are mixed with a low melting glass powder is suitable, and the other is called a silicon ladder polymer (chemical name: polyphenylsiloxane). , (—Si—O—Si—) may be used as a polymer material having a siloxane bond as a main skeleton. Although the thickness of the insulating layer 10 depends on the thickness (height) of the emitter layer 7, it is lower than the emitter layer 7 and is suitably in the range of 5 to 20 μm. The opening width can be about several μm to 100 μm. The control electrode is suitably an Al thin film or an Al—Si thin film, but may be other metal materials.
There is also a method in which the insulating layer 10 has a two-layer structure of a low-melting glass layer and a polymer layer. For example, a small hole is formed in a photosensitive low melting point glass layer and a carbon emitter is embedded therein, followed by polishing to smooth the surface, and then forming a polymer layer to form a small hole again. Good. This method has an advantage that the pattern formation of the carbon emitter becomes easy.

The shielding electrode plate 12 is suitably a low expansion nickel alloy, for example, Ni48-Fe. The thickness is suitably 50 to 300 μm in consideration of workability and mechanical strength, but is practically 100 to 200 μm.
The dielectric layer 13 is similar to the insulating layer 10 described above, and a method using a glass paste obtained by mixing a low-melting glass powder with a filler of ceramic fine particles, a solvent, a binder resin and the like is appropriate. In addition, there is a method in which a dielectric material is attached by vacuum deposition to form an insulating layer. For the adhesion between the surface of the dielectric layer 13 and the control electrode 8 of the emitter structure 2, a glass paste can be similarly used, but polyimide may also be used. Polyimide has low outgassing and good adhesion.

  The dielectric layer 13 is prepared by preparing a tank filled with a paste (or slurry) containing a dielectric powder, dipping only one side by floating the shielding electrode plate 12 in the tank so that the coated surface is in contact with the paste surface. There is a method of forming by drying, baking.

Alternatively, it may be formed by pasting and firing a dielectric sheet that has been processed into a film shape in advance. In either case, the dielectric layer 13 needs to have an opening in accordance with the opening of the shielding electrode plate 12, but ultraviolet rays are applied from the opposite side of the dielectric layer 13 from the state where there is no opening by coating or pasting. The opening can be formed by irradiation and exposure and development. The paste or film must contain a photosensitive material that can be etched by exposure.
Note that up to ½ of the depth of the opening of the shield electrode plate 12 may be covered with a dielectric, but it is not preferable that the entire cross section of the opening is covered because it becomes difficult to control the electron beam.

  Further, since the shield electrode plate 12 undergoes relatively large shrinkage deformation by the first annealing, it is desirable to form a dielectric layer before annealing. Since the low melting point glass also has a characteristic that it is greatly shrunk by the first annealing, the deformation amount of the shield electrode plate 12 after firing can be suppressed. At this time, by setting the expansion coefficient of the dielectric in the vicinity of room temperature to be slightly larger than the expansion coefficient of the shielding electrode plate 12, warping after firing can be reduced to an extent that does not affect the subsequent assembly process. The difference between the coefficients is preferably 2% to 15%.

The black matrix 15 on the anode substrate 4 has a function of improving the contrast of the display device, clarifying the outline of the subpixel, and a function of preventing charge-up by an electron beam due to conductivity. Used. It is formed by exposing and developing a uniform graphite layer having a thickness of 1 to 2 μm.
The phosphors 5 that emit light of the three primary colors red, blue, and green are separately applied by an electron beam of 5 to 15 kV. Y ₂ O ₂ S: Eu is suitable as a red phosphor, ZnS: Au, Cu, Al or ZnS: Cu, Al is suitable as a green phosphor, and ZnS: Ag or ZnS: Ag, Cl is suitable as a blue phosphor. The thickness of the phosphor layer is appropriately 4 to 8 μm, although it depends on the particle size.
Further, the anode electrode 16 is formed by vacuum deposition of a film of Al or the like. A suitable thickness of Al is 500 to 1500 mm.

As for the operating voltage, assuming that the voltage of the control electrode 8 at the time of scanning line selection is 0V, a data pulse of about −30 to −150V is applied to the cathode electrode 6 during light emission. This voltage value depends on the electron emission characteristics of the material of the emitter layer 7 and the distance between the emitter layer 7 and the control electrode 8. A high voltage of 5 to 15 kV is applied to the anode electrode 16 or the anode electrode 16 on the phosphor 14.
However, it is needless to say that a low voltage can be used as appropriate when a phosphor that emits light with a low-voltage electron beam is used.
If the acceleration voltage is low, element deterioration due to an internal discharge phenomenon can be prevented, and insulation of the drive circuit system of the display device can be simplified.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional view of a main part of the field emission display device of the second embodiment.
In this embodiment, a plurality of ribs 17 are erected on the emitter structure 2, and the shield electrode structure 3 and the top of the rib 17 are opposed to each other. Although there is a gap between the dielectric layer 13 of the shield electrode structure 3 and the top of the rib 17, an adhesive material (not shown) is interposed in part or all of this region. That is, the shield electrode structure 3 is supported and fixed on the cathode substrate 1 via the ribs 17.
The rib 17 has a stripe shape parallel to the control electrode 8 shown in FIG. 3 (direction perpendicular to the cross section), and is disposed at a position between the control electrodes 8.
However, each rib 17 does not need to be completely continuous, and a plurality of line segments may be distributed on a straight line. By arranging the line segments, the stress generated when the ribs 17 are formed can be reduced, and the fixing position and the fixing area of the shielding electrode structure 3 can be controlled.
In addition, it is also possible to use a grid-like rib if there is a margin in the pitch of the openings 9a and 9b. By using the lattice shape, the mechanical strength can be increased.

Using the ribs 17 to support and fix the shield electrode structure 3 has the following effects.
I. The region to which the adhesive is applied is away from the control electrode 8, and it is possible to prevent the excess adhesive from flowing into the openings 9a and 9b and inhibiting emission when the adhesive is applied. As the adhesive, a highly viscous material such as a highly thixotropic paste may be used.
B. The distance between the emitter structure 2 and the shield electrode structure 3 can be increased. Further, the distance can be adjusted by the height of the rib 17. As a result, it is possible to make it difficult to cause a short circuit between the control electrode 8 and the shielding electrode plate 12, which is likely to be a problem due to factors such as the scattered material of the emitter layer 7 and deformation of the control electrode 8.

A specific configuration of the rib 17 is formed by a method such as screen printing using a paste obtained by kneading a filler, a binder, a solvent, and the like made of oxide fine particles into low melting glass. The width of the rib 17 depends on the row pitch (pitch of the control electrode 8), but in the case of a single-plate display device, 50 to 200 μm is appropriate. The height of the rib 17 may be about 10 μm, but it can be used up to about 150 μm in consideration of the distance from the shielding electrode plate 12 as described above. A height higher than that is not preferable because the strength of the rib 17 is lowered, but is applicable if the height / width is 1.5 or less.
When CNT is used as the emitter material, the above-described short circuit is less likely to occur if the height is set to be equal to or greater than the maximum length of the CNT. In view of the safety factor, if the height is 1.5 to 2 times the CNT length, the design becomes more practical.

Embodiment 3 FIG.
In the first and second embodiments described above, the shielding electrode plate 12 is made of a metal plate. However, the following problems occur with the use of the metal plate.
I. When manufacturing the shield electrode plate 12 by processing the metal plate, the metal plate larger than the outer dimension of the shield electrode plate 12 is etched to bridge the frame-shaped metal plate peripheral portion and the shield electrode plate 12. Although a process of cutting the thin bridge portion is necessary, the shielding electrode plate 12 may be distorted by the tension accompanying the shearing at the time of cutting.
B. When a large number of electron passage holes 11 are formed, the mechanical strength of the shielding electrode plate 12 is lowered, and there is a risk of deformation due to handling until the dielectric layer 13 is formed. If the shielding electrode plate 12 is made thick in order to increase the strength, it becomes difficult to perform drilling by etching with high accuracy.
C. When heating is performed in the process of bonding the shield electrode plate 12 onto the control electrode 8, the cathode substrate 1 is temporarily deformed by the stress of the insulating layer 10 of the emitter structure 2 and the like. At this time, since the shielding electrode plate 12 is also deformed by its own stress, the cathode substrate 1 formed of the glass substrate may be destroyed by the mutual action force.
D. Since the electric field tends to concentrate at the corners of the shield electrode plate 12, vacuum discharge (low-pressure gas discharge) may occur.
E. When the dielectric layer 13 is formed on one side surface of the shield electrode plate 12, the shield electrode structure 3 is distorted due to the internal stress of the dielectric layer 13. Although the stress can be minimized by aligning the expansion coefficients of the shielding electrode plate 12 and the dielectric layer 13, complete matching cannot be expected in the thermal process in a high temperature range in the formation process of the dielectric layer 13.

Hereinafter, the configuration of the shielding electrode plate 20 that solves these problems will be described.
FIG. 4 shows an example of the shielding electrode plate 20 provided with the electron passage holes 11 corresponding to the positions where the emitter layers 7 are arranged. In this example, it is assumed that the planar shape of the emitter layer 7 is rectangular, and the shape of the electron passage hole 11 is substantially the same as the shape of the emitter layer 7.
If the area where the electron passage holes 11 are arranged is called a “display area”, the electron passage holes 11 are not formed outside the “display area”.
The one shown in FIG. 4 is chamfered into straight lines at the four corners of the shield electrode plate 20.
By adopting this configuration, it is possible to suppress the vacuum discharge from the corner as will be described later. However, as described in the above problem (e), due to thermal expansion at a high temperature, particularly outside the display area. Distortion increases.
On the other hand, in FIG. 5, a hole 21 is formed in almost the entire “outside the display area”. By adopting such a structure, the expansion characteristics of the entire shielding electrode plate 20 are made more uniform, so that the above problem can be solved.

FIG. 6 is a first modification of what is shown in FIG. 5, and the holes 21 “outside the display area” are arranged radially. By adopting such a configuration, the strength against the pulling force increases in a radial manner, which is a solution to the problem (A).

  FIG. 7 shows a second modification of what is shown in FIG. 5, and a plurality of round holes 22 are arranged “outside the display area”. The round hole 22 is not easily reduced in strength with respect to the pulling force, and in this structure, as shown by an arrow A in the figure, the strength in the oblique direction is increased. Therefore, the shielding electrode is used in the direction in which the strength cannot be secured in the “display region”. The plate 3 can be reinforced.

FIG. 8 is a cross-sectional view showing a third modification of what is shown in FIG.
Since the control electrode 8 on the cathode substrate 1 is formed on the insulating layer 10, it is necessary to provide an electrical connection with the lead terminal on the cathode substrate 1. The connecting portion 23 is formed by providing an opening 24 in the insulating layer 10 on the cathode electrode 6 and dropping a paste material such as Ag with a dispenser or a stamping machine so as to contact the control electrode 8 and the cathode electrode 6. The For this reason, there is a problem that a region on which the Ag paste is placed is formed on the control electrode 8 and the shield electrode plate 12 is warped when coming into contact with the shield electrode structure 3.
This is caused by interference between the connection portion 23 and the periphery of the shielding electrode plate 12 in order to reduce the size of the image device by narrowing the “outside display area” area.
In order to avoid this problem, as shown in FIG. 8, a hole 25 larger than the facing area of the connecting portion 23 is formed in the shielding electrode plate 12 so that the connecting portion 23 does not contact the shielding electrode plate 12. .

FIG. 9A shows a rectangular shielding electrode plate 12 having the above problem (d).
FIG. 9B shows the shape of the shielding electrode plate 20 that suppresses the vacuum discharge from the corner 18, and the corner 18 is chamfered in an arc shape so as to have R. Since the angle of the corner 18 is gentle, the rate of occurrence of vacuum discharge can be significantly reduced. In a practical vacuum at a pressure of 1 × 10 ⁻⁴ to 1 × 10 ⁻⁶ Pa, if R is at least 10 mm, vacuum discharge can be effectively suppressed against an anode voltage of 5 kV.
The corner 18 in FIG. 9C is chamfered in a straight line, and the same effect as in FIG. 9B can be obtained.

FIG. 10 is a diagram showing the structure of the shielding electrode plate 27 that solves the above problem (b), FIG. 10 (a) is a partial front view of the shielding electrode plate 27, and FIG. 10 (b) is FIG. 10 (a). FIG. 10C is a cross-sectional view taken along the line C-C in FIG. 1A.
The thickness in the vicinity of the electron passage hole 11 in the “display region” is formed thinner than the outer peripheral edge of the shielding electrode plate 27, and is located at a position corresponding to the space between the control electrodes 8 along the longitudinal direction of each control electrode 8. A collar portion 28 is formed.
The thickness of the flange portion 28 is the same as the thickness of the outer peripheral edge portion of the shielding electrode plate 27, but may be slightly thinner. With this structure, it is possible to perform microfabrication of the electron passage hole 11 with high accuracy by thinning only the region of the electron passage hole 11 while minimizing a decrease in the strength in the longitudinal direction of the flange portion 28. . That is, the electron passage hole 11 may be formed after the plurality of flange portions 28 are formed on the base material of the shielding electrode plate 27.
In general, since the control electrode 8 is in the longitudinal direction (horizontal direction) of the screen, securing the strength in the longitudinal direction is advantageous for preventing deformation during the process.
In order to improve the strength of the control electrode 8 in the short direction (longitudinal direction of the cathode electrode 6), several vertical ribs that cross the control electrode 8 are provided so long as the influence on the image quality is not a problem. It may be formed. At the position where the vertical ridge portion is formed, the ridge is in a lattice shape.
The plate thickness in the vicinity of the electron passage hole 11 between the flange portions 28 is appropriately 5 to 100 μm. In the case of Ni48-Fe, 10 to 60 μm is an optimum range in consideration of strength and workability.

The materials of the cathode substrate 1 and the shielding electrode plate 27 are selected so that the coefficients of thermal expansion are approximately close to each other, but cannot be expected to take close values in the entire temperature region of the heating process. In addition, since each has a complicated structure, there is a problem of stress distribution.
For example, there is a problem of stress between the emitter structure 2 on the cathode electrode 6 and stress between the shielding electrode plate 27 and the dielectric layer 13.

These cause the above problem (c). FIG. 11 is a diagram showing the structure of the shielding electrode plate 29 that solves this problem, and has a structure in which the flange structure of the shielding electrode plate 27 shown in FIG.
By providing a thin region at the corner 18, temporary warpage deformation of the shielding electrode plate 29 at high temperatures is likely to occur, and cracking of the cathode substrate 1 at the corner where stress tends to concentrate can be reduced. it can.

Embodiment 4 FIG.
FIG. 12 is a cross-sectional view of a main part of the field emission display device of the fourth embodiment.
In this embodiment, the shield electrode plate 30 covers the entire surface including the front and back surfaces of the metal electrode plate 32 in which the electron transmission holes 31 are formed and the inner surface of the electron transmission holes 31 with the dielectric film 33. The entire surface on the anode substrate 4 side from above is covered with a metal film 34.
Even in this structure, the function as the shielding electrode plate 30 can be achieved while maintaining insulation from the cathode substrate 1.

  According to the shielding electrode plate 30, since the insulating layer 10 is formed on the entire front and back surfaces, it is easy to form a high-quality dielectric film 33 using a film forming method such as a thermal spraying method or a sputtering method. A method of forming the shielding electrode plate 30 by oxidizing it is also possible. Films obtained by thermal spraying, sputtering, and oxidation are dense and have high withstand voltage.

1 is a cross-sectional view of a main part of a field emission display device according to a first embodiment. It is a top view which shows the positional relationship of the cathode electrode of FIG. 1, and a control electrode. FIG. 6 is a cross-sectional view of a main part of a field emission display device according to a second embodiment. FIG. 10 is a partial front view of a shielding electrode plate in the field emission display device according to the third embodiment. It is a partial front view which shows the modification of the shielding electrode board of FIG. It is a partial front view which shows the other modification of the shielding electrode board of FIG. It is a partial front view which shows the other modification of the shielding electrode board of FIG. FIG. 10 is a partial cross-sectional view showing another form of the field emission display device according to the third embodiment. FIG. 9A is a front view of a rectangular shield electrode plate, FIG. 9B is a front view of the shield electrode plate having a rounded corner, and FIG. 9C is a shield electrode plate. It is a front view of the shielding electrode plate by which the corner | angular part was chamfered. 10 (a) is a partial front view of the shielding electrode plate, FIG. 10 (b) is a cross-sectional view taken along line BB in FIG. 10 (a), and FIG. 10 (c) is FIG. 10 (a). It is arrow sectional drawing along CC line. It is a partial front view which shows the modification of the shielding electrode board of FIG. FIG. 10 is a cross-sectional view of main parts of a field emission display device according to a fourth embodiment.

Explanation of symbols

  1 cathode substrate, 2 emitter structure, 3 shielding electrode structure, 4 anode electrode, 5 phosphor structure, 6 cathode electrode, 7 emitter layer, 8 control electrode, 9a, 9b opening, 10 insulating layer, 11, 31 electron passage hole , 12, 20, 27, 29, 30 Shield electrode plate, 13 Dielectric layer, 14 Phosphor, 16 Anode electrode, 17 Rib, 18 Corners, 21, 22, 25 holes, 28 Grooves, 33 Dielectric film, 34 Metal film.

Claims (8)

A cathode substrate;
A plurality of cathode electrodes formed on the surface of the cathode substrate;
An emitter layer formed on the cathode electrode;
A plurality of control electrodes formed through an insulating layer on the cathode substrate and having openings formed in portions facing the emitter layer;
An anode substrate disposed opposite the cathode substrate;
A phosphor formed on the surface of the anode substrate on the cathode substrate side;
An anode electrode formed on the surface of the phosphor;
A shielding electrode plate disposed between the control electrode and the anode electrode and having a plurality of electron passage holes through which electrons passing from the emitter layer through the opening and toward the phosphor pass. In a field emission display device,
Wherein the shielding electrode plate, at least on the excluding the anode electrode side and the control electric pole surface, the entire surface is formed a dielectric layer which is fixed by an adhesive in surface contact,
A field emission display device, wherein a plurality of holes are formed in the entire outer peripheral edge region of the shielding electrode plate which does not face the emitter layer. A cathode substrate;
A plurality of cathode electrodes formed on the surface of the cathode substrate;
An emitter layer formed on the cathode electrode;
A plurality of control electrodes formed through an insulating layer on the cathode substrate and having openings formed in portions facing the emitter layer;
An anode substrate disposed opposite the cathode substrate;
A phosphor formed on the surface of the anode substrate on the cathode substrate side;
An anode electrode formed on the surface of the phosphor;
A shielding electrode plate disposed between the control electrode and the anode electrode and having a plurality of electron passage holes through which electrons passing from the emitter layer through the opening and toward the phosphor pass. In a field emission display device,
In the shielding electrode plate, a dielectric layer is formed at least on the surface on the control electrode surface side excluding the anode electrode side,

In addition, the insulating layer is provided with a rib whose tip surface is bonded to the dielectric layer with an adhesive.
A field emission display device, wherein a plurality of holes are formed in the entire outer peripheral edge region of the shielding electrode plate which does not face the emitter layer.   3. The field emission type according to claim 1, wherein the shielding electrode plate has a substantially rectangular overall shape, and a corner portion of the shielding electrode plate is chamfered into a linear shape or an arc shape. 4. Display device.   The thickness of the shielding electrode plate is not opposite to the emitter layer, and the thickness around the electron passage hole formed in the inner region of the outer peripheral region of the shielding electrode plate is larger than the thickness of the outer peripheral region. The field emission display device according to claim 1, wherein the field emission display device is thin. The plurality of holes, a field emission display device according to any one of claim 1 to 4, characterized in that the longitudinal direction of the opening shape are arranged radially from the center of the shield electrode plate. The shield electrode plate, any thickness of the region facing the region between the control electrode of claim 1 to 5, characterized in that it has a thick ridge compared to the thickness of the periphery of the electron passing hole The field emission display device according to claim 1. A connecting portion for electrically connecting the control electrode and the control electrode lead electrode between the control electrode and the control electrode lead electrode on the cathode substrate;
It said shielding electrode plate, field emission display device according to any one of claim 1 to 6, characterized in that the hole in a portion facing the connecting portion is formed. The field emission display device according to claim 7 , wherein an outer diameter of the hole is larger than a facing area of the connection portion facing the hole.

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