JP2009134882A - Image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize electrical resistance of a spacer which keeps a space between an anode board and a cathode board against an atmospheric pressure. <P>SOLUTION: A spacer 4 is formed of glass and has a slight electrical conductivity. In order to stabilize resistance of the spacer 4, conductive particles 100 are coated on the surface of the spacer 4, forming a uniform irregularity on the surface of the spacer 4. Uniform particles are required to be coated to form the uniform irregularity. To form uniform particles, fine particles are made secondary particles having uniform diameters with a cyclone collecting machine, and then the secondary particles are dispersed in such solvent as alcohol to form a sol which is coated on the spacer 4. Since uniform particles are coated on the spacer surface, the resistance of the spacer 4 is stabilized, while releasing of secondary electrons from the spacer 4 is suppressed and dispersing of heat from the spacer 4 is promoted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flat display device in which the inside is evacuated, electron emission sources are arranged in a matrix on the rear substrate, and phosphors corresponding to the front substrate are arranged. Related to antistatic technology.

  A field emission display (FED) is a display device in which an inside sandwiched between two glass substrates is evacuated, electron emission sources are arranged in a matrix on one substrate, and phosphors are arranged on a counter substrate. The FED forms an image when electrons from an electron emission source strike a phosphor and emits light. In the future, brightness, contrast, moving image characteristics, etc. can provide excellent performance similar to a cathode ray tube. It is expected as a TV display.

  However, in the FED, it is necessary to accelerate electrons to make the phosphor shine by applying a high voltage of about 10 KV to the anode. Since a high voltage of about 10 KV is applied between the anode substrate on which the phosphor screen is formed and the cathode substrate on which the electron source is formed, a considerably high electric field is formed inside the display device. Accordingly, sparks are likely to occur between the anode substrate and the cathode substrate.

  A spacer for withstanding atmospheric pressure is installed between the anode substrate and the cathode substrate. If this spacer is an insulator, electrons are charged on the surface, which affects the trajectory of the electron beam from the electron source. Further, when the spacer is charged, sparks are likely to occur between the anode substrate and the cathode substrate. In order to prevent this, a technique is known in which the spacer itself has a certain degree of conductivity, or a conductive material is applied to the surface of the spacer.

  A technique for preventing the spacer from being charged by applying a conductive polymer to the surface of the insulating spacer is disclosed in “Patent Document 1”. Further, “Patent Document 2” has a technique for improving the heat conduction from the spacer and improving the antistatic effect by coating the surface of the conductive spacer with conductive crystallized glass to form irregularities on the surface. Are listed.

JP 2000-1003006 A Japanese Patent Application No. 2006-184531

  In the technique described in “Patent Document 1”, an insulating spacer is coated with a conductive polymer to prevent the spacer from being charged. If the resistance of the spacer is too small, the current flowing through the spacer increases and power consumption increases. Further, if the resistance of the spacer is too large, the effect of preventing charging cannot be sufficiently obtained. The FED is baked at a high temperature in processes such as sealing and exhausting the cathode substrate and the anode substrate. Organic substances such as polymers may be altered during baking, and the resistivity and the like may change. Therefore, it is difficult to control the resistance of the spacer with the polymer coating.

  As described in “Patent Document 2”, when conductive crystallized glass is applied to the surface of the spacer, irregularities are formed on the surface of the glass when the glass is crystallized. When unevenness is formed on the surface, it is possible to improve the heat dissipation effect from the spacer and to improve the antistatic effect. However, in order to form the necessary irregularities with crystallized glass, it is necessary to apply the glass thickly. When the conductive crystallized glass is applied thickly, the resistance of the spacer becomes too small, and the power consumption increases due to the current flowing through the spacer.

  The present invention has been made in order to solve the above-described conventional problems, and forms irregularities on the surface of the spacer by coating the surface of the spacer with relatively uniform particles. Relatively uniform particles can be formed by making primary particles having a small particle size into secondary particles in a cyclone collector using a binder. Specific means are as follows.

  (1) A cathode substrate having an electron source formed in a matrix and an anode substrate facing the cathode substrate and having an effective screen formed by forming a phosphor at a location corresponding to the electron source, the cathode substrate A conductive spacer is provided between the cathode substrate and the anode substrate to define a distance between the cathode substrate and the anode substrate. The display device is characterized in that the spacer is coated with conductive and insulating particles, and the surface of the spacer is formed with irregularities due to the particles.

  (2) The display device according to (1), wherein the spacer is made of conductive glass.

  (3) The display device according to (1), wherein the particles include particles having a positive temperature coefficient of resistance.

  (4) The display device according to (4), wherein the particles having a positive resistance temperature coefficient are barium titanate, strontium titanate, or PZT.

  (5) The display device according to (1), wherein the insulating fine particles include any one of iron oxide, chromium oxide, and titanium oxide.

  (6) a cathode substrate having an electron source formed in a matrix, and an anode substrate facing the cathode substrate and having an effective screen formed by forming a phosphor at a location corresponding to the electron source; A conductive spacer is provided between the cathode substrate and the anode substrate to define a distance between the cathode substrate and the anode substrate. Is a display device that is maintained in a vacuum, wherein the spacer is coated with secondary particles bound with a plurality of primary particles, and the surface of the spacer is formed with irregularities due to the particles. A display device.

  (7) The display device according to (6), wherein the secondary particles include conductive primary particles and insulating primary particles.

  (8) The display device according to (6), wherein the diameter of the primary particles is 1 μm or less.

  (9) The display device according to (6), wherein the diameter of the secondary particles is 10 μm or less.

  (10) The display device according to (6), wherein the diameter of the secondary particles is 5 μm or less.

  (11) The display device according to (6), wherein the spacer is made of conductive glass.

  According to the present invention, since the spacer is coated with relatively uniform secondary particles, the unevenness formed on the surface of the spacer can be made relatively uniform. Further, since the unevenness is formed on the surface of the spacer by the particles, it is not necessary to increase the thickness of the coating film, and the resistance of the spacer and the surface unevenness can be set appropriately.

  Since the primary particles, which are fine particles, are formed in the cyclone collector via the binder, uniform secondary particles can be formed, and as a result, the unevenness on the surface of the spacer can be easily controlled. I can do it.

  Since uniform unevenness can be formed by conductive particles on the spacer base material, an appropriate resistance value to the spacer can be ensured, and emission of secondary electrons from the spacer can be suppressed by the unevenness. Therefore, charging of the spacer by secondary electrons can be prevented. Moreover, the effect of heat radiation from the spacer can be increased by forming irregularities on the spacer surface.

  In addition, by using a thermally stable material as the secondary particles, a change in the resistance value of the spacer during the FED manufacturing process can be suppressed, and the resistance of the spacer can be appropriately controlled.

  The best mode of the present invention will be described below in detail with reference to the drawings of the embodiments.

  FIG. 1 is a plan view showing a first embodiment of the present invention. In FIG. 1, an anode substrate 2 is installed on a cathode substrate 1 via a sealing portion 3. On the cathode substrate 1, scanning lines extend in the horizontal direction, and data signals extend in the vertical direction. A signal is supplied to the scanning line and the data signal line from the outside via the terminal 5. An electron emission source is disposed near the intersection of the scanning line and the signal line. Therefore, a large number of electron emission sources are arranged in a matrix. Various electron emission sources such as the so-called MIM system, SED system, Spindt system, and carbon nanotube have been developed. The present invention can be applied to any electron emission source.

  The inside of the sealing part 3 surrounding the cathode substrate 1 and the anode substrate 2 and the periphery is kept in a vacuum. Therefore, the anode substrate 2 and the cathode substrate 1 are bent by the atmospheric pressure, and the interval between the cathode substrate 1 and the anode substrate 2 cannot be secured. Alternatively, the cathode substrate 1 or the anode substrate 2 is destroyed. In order to avoid this, a spacer 4 is provided between the cathode substrate 1 and the anode substrate 2. The spacer 4 is made of ceramic or glass and is generally installed on the scanning line so as not to hinder image formation.

  The spacer 4 is installed on the scanning line of this effective screen area. On the anode substrate 2, red, green, and blue phosphors 21 that emit light by an electron beam projection are formed corresponding to the electron emission sources. A black matrix (BM22) is formed around the phosphor 21 to improve image contrast. A metal back 23 made of Al is formed so as to cover the black matrix. A high voltage is applied to the metal back 23, and the electron beam emitted from the cathode is accelerated and projected onto the phosphor 21.

  In order to generate light from the phosphor 21 by the electron beam, the electron beam must have a certain amount of energy, and therefore, a high voltage of 8 KV to 10 KV is applied to the metal back 23 of the anode substrate 2. In this embodiment, a high voltage introduction terminal 60 for supplying a high voltage from the outside is provided on the cathode substrate 1 side, and a high voltage is supplied to the anode substrate 2 through a contact spring. Since the inside of the display device must be kept in vacuum, an exhaust hole 81 and an exhaust pipe 8 are provided on the back side of the display device in FIG.

  FIG. 2 is a side view of FIG. 1 viewed from the D direction. In FIG. 2, the cathode substrate 1 and the anode substrate 2 face each other with a predetermined distance through the sealing portion 3. The cathode substrate 1 is formed larger as the terminals 5 and the like are installed. Under the cathode substrate 1, an exhaust substrate 6 for attaching the exhaust pipe 8 and a high voltage introduction terminal is attached. The exhaust substrate 6 is attached to the cathode substrate 1 through an exhaust substrate sealing portion. In FIG. 2, an exhaust pipe 8 for evacuating the inside of the display device is drawn on the exhaust substrate 6 in a state where the chip is turned off.

  3 is a cross-sectional view taken along the line AA in FIG. In FIG. 3, the data signal line 12 extends in a direction perpendicular to the paper surface. In this embodiment, an electron emission source 14 is formed on the data signal line 12. The scanning line 11 is formed in a direction perpendicular to the data signal line 12 through the insulating film 13. In FIG. 3, the scanning line 11 extends outside the sealing portion 3. A spacer 4 for maintaining the distance between the cathode substrate 1 and the anode substrate 2 is provided on the scanning line 11. The spacer 4 is fixed to the metal back 23 by a frit glass 41 on the anode substrate 2 side and on the scanning line by a frit glass 42 on the cathode substrate 1 side.

As the spacer base material, conductive glass described later is used. Although the spacer base material is conductive, the side surfaces of the spacer 4 are coated with conductive particles as described in detail later in order to stabilize the resistance value and suppress secondary electrons. The spacer base material can also be made of insulating glass. In this case, the conductivity of the spacer 4 can be obtained from conductive fine particles coated on the surface. The spacer 4 is provided with a conductivity of about 10 ⁷ to 10 ¹¹ Ω · cm, preferably about 10 ⁸ to 10 ⁹ Ω · cm, in a state where conductive particles are coated.

  In order to keep the inside of the display device in a vacuum, the anode substrate 2 and the sealing frame 31 are sealed by the sealing material 32, and the cathode substrate 1 and the sealing frame 31 are sealed by the sealing material 33. In this embodiment, the sealing material 32 and the sealing material 33 use different types of frit glass having different bonding temperatures.

  On the anode substrate 2 side, phosphors 21 such as red, green, and blue are arranged at locations corresponding to the electron emission sources 14, and the phosphors 21 emit light by being projected onto the electron beam, and an image is displayed. It is formed. The space between the phosphors 21 is filled with BM 22 and contributes to the improvement of the contrast of the image. For example, the BM 22 has a two-layer structure of chromium and chromium oxide. A metal back 23 made of Al is formed so as to cover the phosphor 21 and the BM 22. A high voltage of about 8 KV to 10 KV is applied to the metal back 23 to accelerate the electron beam. The accelerated electron beam penetrates the metal back 23 and strikes the phosphor 21 to cause the phosphor 21 to emit light.

  In FIG. 3, after the anode substrate 2 and the cathode substrate 1 are sealed through the sealing frame 31 and the frit glass, the inside of the FED is evacuated to a vacuum through the exhaust pipe. The thickness of the cathode substrate 1 and the thickness of the anode substrate 2 are about 3 mm. The distance between the cathode substrate 1 and the anode substrate 2 is about 2.8 mm. In order to apply a high voltage of 8 KV to 10 KV at this narrow interval, a high electric field is formed inside the display device, and there is a danger of sparking. In order to prevent sparks, the spacer 4 and the frit glass to which the spacer 4 is fixed are provided with electrical conductivity to prevent the spacer 4 from being charged.

  4 is a cross-sectional view taken along the line BB of FIG. In FIG. 4, a through hole 10 is formed in the cathode substrate 1, and the display device is exhausted or a high voltage is supplied through the through hole 10. An exhaust substrate 6 is installed through the exhaust substrate sealing portion 7 so as to cover the through hole 10 of the cathode substrate 1, and the inside of the display device is kept in vacuum. The exhaust substrate sealing portion 7 has the same basic configuration as the cathode substrate 1 and the anode substrate 2 sealing portion 3. That is, the exhaust substrate frame 71 is sealed with the frit glass 32, and the exhaust substrate frame 71 is sealed with the cathode substrate 1 with the frit glass 33. In this embodiment, the frit glass 32 has a higher bonding temperature than the frit glass 33. In this embodiment, the frame 31 for sealing the anode substrate 2 and the cathode substrate 1 and the frame for sealing the cathode substrate 1 and the exhaust substrate 6 have the same thickness, but the thickness of the frame is as required. Can be set freely.

The high voltage introduction terminal 60 penetrates the exhaust board 6 while maintaining airtightness with the outside. The high voltage introduction terminal 60 is sealed with the exhaust substrate 6 by the frit glass 32.
An Fe—Ni alloy is used for the high voltage introduction terminal 60, but the ratio of Fe and Ni is determined in consideration of the thermal expansion of the exhaust substrate 6. In this example, Ni is 48%. An exhaust hole 81 is formed in the exhaust substrate 6, and an exhaust pipe 8 is sealed in the exhaust hole 81 via a frit glass 32. The inside of the display device is evacuated through the exhaust pipe 8, and then the exhaust pipe 8 is chipped off and the inside of the display device is kept in vacuum. FIG. 4 shows a state in which the exhaust pipe 8 is chipped off.

  The frit glass 32 has a higher bonding temperature than the frit glass 33, and accordingly, the reliability of sealing the exhaust pipe and the high voltage introduction terminal is increased. In other words, since the exhaust pipe and the high voltage introduction terminal are sealed regardless of the baking of the cathode terminal on which the electron source is formed, the reliability of the sealing is increased by using frit glass having a high bonding temperature. ing.

  An anode terminal 24 for contacting the contact spring 50 is formed on the anode substrate 2. Since a relatively large current flows through the anode terminal 24, reliability is important. In this embodiment, the structure near the anode terminal 24 is as follows. A BM 22 of chromium and chromium oxide is formed on the anode substrate 2, and a metal back 23 made of Al is formed so as to cover the BM 22. This is the same configuration as the effective screen of the screen. In this embodiment, a conductive film as the anode terminal 24 is formed on the metal back 23 with a thickness of about 10 μm.

  In this embodiment, the anode terminal 24 is formed by applying a silver paste by printing and then baking it. There is no need to provide a special process for firing the anode terminal 24. For example, the anode terminal 24 may be performed simultaneously with the firing process when the spacer 4 is fixed.

  The silver paste is obtained by dispersing silver particles having a diameter of 1 μm to several μm in an organic solvent having a high viscosity. After firing, the silver particles are connected to each other to have conductivity. In some cases, the conductive film should have some resistance. In such a case, the resistance can be adjusted by further mixing a paste for frit glass with a normal silver paste. Note that the material of the conductive film is not limited to silver paste, and Ni paste in which Ni particles are dispersed, Al paste in which Al particles are dispersed, and the like can also be used. A graphite film bonded with a binder can also be used. The graphite in this case is preferably graphite. The resistance of the graphite film can be adjusted, for example, by mixing bengara (iron oxide) with graphite.

  FIG. 5 is a schematic view showing a CC cross section of FIG. In FIG. 5, data signal lines 12 extend in the horizontal direction on the cathode substrate 1. The scanning line 11 extends in the normal direction of the paper surface at right angles to the data signal line 12. An electron source 14 is disposed on the data signal line 12 between the scanning lines. The electron source 14 includes a data signal line 12 serving as a lower electrode and an upper electrode that is electrically connected to the scanning line 11 via a tunnel insulating film. In this embodiment, an MIM electron source is used as the electron source 14, but the present invention is not limited to the MIM electron source but can be applied to other electron sources.

  A phosphor 21 is formed on the anode substrate 2 and the space between the phosphor and the phosphor is covered with a BM 22. A metal back 23 is formed by sputtering Al over the phosphor 21 and the BM 22. An anode voltage that is a high voltage of about 8 KV to 10 KV is applied to the metal back 23. The electron beam emitted from the electron source 14 is accelerated by the anode voltage. The electron beam emitted from the electron source 14 penetrates the metal back 23 and strikes the phosphor 21 to cause the phosphor 21 to shine, thereby forming a color image. The electron beam spreads when emitted from the electron source 14, but is designed to be slightly larger than each phosphor on the phosphor screen.

  In order to maintain the distance between the anode substrate 2 and the cathode substrate 1, the spacer 4 is installed as described with reference to FIG. The spacer 4 is disposed between the scanning line 11 on the cathode substrate 1 and the metal back 23 on the anode substrate 2. At this position, the spacer 4 does not interfere with image formation.

  The base material of the spacer 4 uses conductive glass. The conductive glass contains a transition metal, and particularly contains at least one selected from vanadium oxide, tungsten oxide, and molybdenum oxide as a transition metal oxide. In addition, barium oxide, antimony oxide, and the like can be included. Among these oxides, vanadium oxide has the highest conductivity. On the other hand, tungsten oxide has an effect of improving the heat resistance of glass, and molybdenum oxide has an effect of reducing secondary electrons of glass.

  In addition to the transition metal oxides described above, phosphorus oxide is used as a material for the spacer 4 as an oxide for vitrification. Moreover, it is also possible to contain barium oxide together with the phosphorus oxide. Moreover, the thermal expansion coefficient of glass can be controlled by the content of barium oxide.

  In this embodiment, WVPO glass containing tungsten oxide and vanadium oxide as the base material of the spacer 4 and containing phosphorus oxide as the glass component is used. In addition, WVVMo-PO glass containing molybdenum oxide can also be used.

  In order to keep the inside of the FED in a vacuum, the cathode substrate 1 and the anode substrate 2 are sealed in the manufacturing process, the inside of the FED is evacuated, and the like. When exposed to such a high temperature, the resistance of the conductive glass changes. The current flowing through the spacer 4 must be set appropriately from the viewpoint of power consumption of the spacer 4 and prevention of charging of the spacer 4. That is, the resistance of the spacer 4 must be properly controlled. However, if the resistance of the spacer 4 changes in the FED manufacturing process, the current flowing through the spacer 4 cannot be controlled, which is a problem.

  In the present invention, by coating the surface of the spacer 4 with conductive fine particles, the spacer base material can be protected from the oxidizing atmosphere, and the resistance of the spacer 4 can be controlled appropriately. That is, in the present invention, the primary particles 110 shown in FIG. 6 are bound to form secondary particles 100 having a relatively uniform particle diameter, and the secondary particles 100 are coated on the spacers 4 to form the spacer base material. It protects the surface.

  According to the present invention, since the secondary particles 100 are coated on the surface of the spacer 4, irregularities are formed on the coating surface. If irregularities are formed on the surface of the spacer 4, the following advantages are obtained. First, since the surface area of the spacer 4 is increased, the heat dissipation effect from the spacer 4 can be increased. When the temperature of the spacer 4 rises, the conductivity generally increases, so that the current flowing through the spacer 4 increases, and the temperature of the spacer 4 is further raised, and this cycle is repeated, so that the temperature and current of the spacer 4 portion are increased. Runaway may occur. According to the present invention, since the temperature rise of the spacer 4 can be suppressed, such runaway can be suppressed.

  The second is the effect of suppressing secondary electrons from the spacer. When the electrons hit the spacer 4, secondary electrons are emitted from the spacer 4. It is difficult to predict how much secondary electrons are emitted by primary electrons. However, the potential of the spacer 4 changes depending on the amount of secondary electrons emitted. When the potential of the spacer 4 changes depending on the amount of secondary electron emission, the trajectory of the electron beam is affected. Therefore, in order to keep the trajectory of the electron beam constant, the smaller the amount of secondary electron emission, the better. If irregularities are formed on the surface, emission of secondary electrons can be suppressed. This is presumably because secondary electrons from the concave and convex portions are trapped before being emitted to the outside.

  In order to stabilize the heat dissipation of the spacer 4 and to suppress secondary electrons stably, it is desirable that the unevenness formed on the surface of the spacer 4 is uniform. In the present invention, uniform particles can be coated by a method described later, so that the operation of the spacer 4 can be stabilized.

  In order to make the unevenness of the surface of the spacer 4 uniform, it is necessary to make the diameter of the particles to be coated uniform. In the coating of the particles on the spacer 4, the particles are dispersed in a solvent such as alcohol, and this dispersion is sprayed onto the spacer 4. When the fine particles are dispersed in a solvent, the fine particles are aggregated, and the diameter of the aggregated fine particles becomes very uneven. Even if such non-uniform particles are coated, it is difficult to form uniform irregularities on the surface of the spacer 4.

  In the present invention, before forming the coating liquid, the secondary particles 100 having a required diameter are formed from the primary particles 110 that are fine particles using a binder. FIG. 6 shows an example in which the secondary particles 100 are formed by binding the primary particles 110. FIGS. 6A, 6 </ b> B, and 6 </ b> C are examples of the shape of the secondary particle 100. The secondary particles 100 as shown in FIG. 6A, FIG. 6B, and FIG. 6C can be set according to the manufacturing conditions of the secondary particles 100 in the cyclone collector SD shown in FIG. Here, the primary particle 110 is about 0.1 μm to about 1 μm. The primary particles 110 are bound to form secondary particles 100 of 10 μm or less, preferably 5 μm or less. Since the secondary particles 100 are already bound with the primary particles 110, even when dispersed in a solvent such as alcohol, further aggregation is unlikely to occur.

FIG. 7 is a schematic diagram of a cyclone collector SD showing a method for producing the secondary particles 100. In FIG. 7, the sol-like mixture of the primary particles 110 and the binder is sprayed into the cyclone collector SD from the spray nozzle SP formed in the cyclone collector SD. As the binder, for example, silane SiH ₄ or a material containing a silane coupling agent can be used. As the binder, a compound that vitrifies by a sol-gel reaction may be used.

  In FIG. 7, hot air of 100 ° C. to 250 ° C. is introduced into the cyclone collector SD from the hot air introduction nozzle HW at the lower left portion of the cyclone collector SD. The hot air rotates along the cylinder in the cyclone collector SD. The sol in which the primary particles 110 injected from the spray nozzle SP and the binder are mixed reacts with hot air to form secondary particles 100. The formed secondary particles 100 gradually descend while being caught in hot air, and are collected from a collection hole GT formed in the lower part of the cyclone collector SD. The hot air is collected from the exhaust nozzle EX formed in the upper part of the cyclone collector SD and reused.

  In the cyclone collector SD, the secondary particles 100 gradually descend while being entrained in hot air, but particles having a larger weight settle faster. Therefore, the diameter of the secondary particles 100 to be collected can be more accurately selected by selecting the timing at which the sol in which the primary particles 110 and the binder are mixed and the timing at which the secondary particles 100 are collected from the spray nozzle SP. Can be controlled.

  On the other hand, the diameter of the secondary particles 100 varies depending on the pressure of the sol injected from the spray nozzle SP into the cyclone collector SD, that is, the flow rate of the sol, and the temperature and air volume of the hot air. If drying of the sol in which the primary particles 110 and the binder are mixed is slow, the secondary particles 100 become large. Thus, the particle size of the secondary particles 100 can be designed according to the unevenness formed on the spacer 4.

  The secondary particles 100 thus formed are dispersed in a ketone or an alcohol solvent, and the spacer 4 is coated by spraying. Then, preliminary baking is performed at 100 ° C. to 250 ° C. The coated material needs to be fired at 350 ° C. to 500 ° C. for about 30 to 120 minutes to form a strong film. Since the baking conditions necessary for the main baking are present in the sealing or exhausting process in the FED manufacturing process, this process may be used.

  The above is a general method for producing secondary particles 100. In the present invention, the coating on the spacer 4 must be a conductor having an appropriate resistance. In order for the coated material to have an appropriate resistance, the fine particles to be coated must be a mixture of an insulating material and a conductive material.

As the insulating particles, iron oxide, chromium oxide, or the like can be used. Titanium oxide also has very high resistance and can be used as insulating particles. On the other hand, the conductive particles may be oxide metal such as ATO or ITO, metal such as gold, silver or Ni, or high resistance carbide such as TiC or SiC. Furthermore, barium titanate, strontium titanate, and PZT (Pb (Tix, Zr1-x) _O3 ) exhibiting the properties of PTC (Positive Temperature Coefficient) can be used as the conductive fine particles. Since the fine particles having properties increase in resistance as the temperature of the spacer 4 rises, thermal runaway can be prevented.

  The formation method of the secondary particles 100 by the cyclone collector SD is the same for both the insulating particles and the conductive particles. Actually, a mixture of primary particles 110 of insulating particles and conductive particles is mixed with a binder and introduced into a cyclone collector SD as a sol to produce secondary particles 100. The finished secondary particles 100 include insulating particles and conductive particles. The conductivity of the film coated on the spacer 4 differs depending on the mixing ratio of the insulating primary particles 110 and the conductive primary particles 110. That is, the resistance value can be designed by the ratio of conductive particles and insulating particles.

  In the above description, an example of spraying is given as a method for coating the spacer 4 with the secondary particles 100. However, the coating of the secondary particles 100 on the spacer 4 can be performed not only by spraying but also by dipping, dicing (transfer) or the like. That is, a sol-gel coating liquid containing the secondary particles 100 may be prepared and the dipping or the like may be performed.

  The coating fine particles have a smaller resistance change due to baking than the spacer base material. Therefore, the resistance of the spacer 4 can be controlled more accurately, and the current flowing through the spacer 4 can be stabilized. Although the above description has been made on the assumption that the base material of the spacer 4 is conductive glass, the present invention can also be applied to insulating glass. Moreover, although the base material of the spacer 4 was demonstrated as glass, this invention is applicable also when the base material of the spacer 4 is formed with the ceramic.

It is a top view of FED of this invention. It is a side view of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is an example of the secondary particle of this invention. It is a schematic diagram of the cyclone collector which manufactures a secondary particle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cathode substrate, 2 ... Anode substrate, 3 ... Sealing part, 4 ... Spacer, 5 ... Terminal, 6 ... Exhaust substrate, 8 ... Exhaust pipe, 10. .. Through hole, 11... Scanning line, 12... Data signal line, 13 .. insulating film, 14... Electron source, 21. ..Metal back, 24 ... Anode terminal, 31 ... Sealing frame, 32, 33, 41, 42 ... Frit glass, 50 ... Contact spring, 100 ... Secondary particles, 110 ..Primary particles, SD ... Cyclone collector.

Claims (11)

A cathode substrate in which an electron source is formed in a matrix; and an anode substrate facing the cathode substrate and having a phosphor formed at a location corresponding to the electron source to form an effective screen, the cathode substrate and the anode A conductive spacer that defines the distance between the cathode substrate and the anode substrate is installed between the substrate and a sealing portion is formed around the cathode substrate and the anode substrate so that the inside is evacuated. A display device to be held,
A display device, wherein the spacer is coated with conductive and insulating particles, and the surface of the spacer is formed with irregularities due to the particles.   The display device according to claim 1, wherein the spacer is made of conductive glass.   The display device according to claim 1, wherein the particles include particles having a positive resistance temperature coefficient.   5. The display device according to claim 4, wherein the particles having a positive resistance temperature coefficient are barium titanate, strontium titanate, or PZT.   The display device according to claim 1, wherein the insulating fine particles include any one of iron oxide, chromium oxide, and titanium oxide. A cathode substrate in which an electron source is formed in a matrix; and an anode substrate facing the cathode substrate and having a phosphor formed at a location corresponding to the electron source to form an effective screen, the cathode substrate and the anode A conductive spacer that defines the distance between the cathode substrate and the anode substrate is installed between the substrate and a sealing portion is formed around the cathode substrate and the anode substrate so that the inside is evacuated. A display device to be held,
A display device, wherein the spacer is coated with secondary particles obtained by binding a plurality of primary particles, and the surface of the spacer is formed with irregularities due to the particles.   The display device according to claim 6, wherein the secondary particles include conductive primary particles and insulating primary particles.   The display device according to claim 6, wherein a diameter of the primary particles is 1 μm or less.   The display device according to claim 6, wherein a diameter of the secondary particles is 10 μm or less.   The display device according to claim 6, wherein a diameter of the secondary particles is 5 μm or less.   The display device according to claim 6, wherein a material of the spacer is conductive glass.

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