JP3768697B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electron beam apparatus and an image forming apparatus such as a display apparatus as an application thereof.
[0002]
[Prior art]
Conventionally, two types of electron-emitting devices, a hot cathode device and a cold cathode device, are known. Among these, as the cold cathode device, for example, a surface conduction type emission device, a field emission type device (hereinafter referred to as FE type), a metal / insulating layer / metal type emission device (hereinafter referred to as MIM type) and the like are known. Yes.
[0003]
As surface conduction electron-emitting devices, for example, MIElinson, Radio Eng. Electron Phys., 10, 1290, (1965) and other examples described later are known.
[0004]
The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows in parallel to a film surface in a small-area thin film formed on a substrate. As this surface conduction electron-emitting device, SnO by Erinson et al. ₂ In addition to those using thin films, those using Au thin films [G. Dittmer: “Thin Solid Films”, 9,317 (1972)], In ₂ O _Three / SnO ₂ By thin film [M. Hartwell and CGFonstad: “IEEE Trans.ED Conf.”, 519 (1975)], or by carbon thin film [Hisa Araki et al .: Vacuum, Vol. 26, No. 1, 22 (1983)] Etc. have been reported.
[0005]
As a typical example of the device configuration of these surface conduction electron-emitting devices, the above-described M.P. FIG. 3 shows a plan view of a device by Hartwell et al. In the figure, reference numeral 3001 denotes a substrate, and 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. By applying an energization process called energization forming to be described later to the conductive thin film 3004, an electron emission portion 3005 is formed. The interval L in the drawing is set to 0.5 to 1 [mm], and W is set to 0.1 [mm]. For convenience of illustration, the electron emission portion 3005 is shown as a rectangular shape in the center of the conductive thin film 3004. However, this is a schematic shape and faithfully represents the actual position and shape of the electron emission portion. I don't mean.
[0006]
M.M. In the above-described surface conduction electron-emitting devices such as the device by Hartwell et al., It is common to form the electron-emitting portion 3005 by performing an energization process called energization forming on the conductive thin film 3004 before electron emission. there were. That is, the energization forming means that the conductive thin film 3004 is energized by applying a constant DC voltage or a DC voltage boosted at a very slow rate of, for example, about 1 V / min to both ends of the conductive thin film 3004. Is locally destroyed, deformed, or altered to form an electron emitting portion 3005 in an electrically high resistance state. Note that a crack occurs in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. When an appropriate voltage is applied to the conductive thin film 3004 after the energization forming, electrons are emitted in the vicinity of the crack.
[0007]
Examples of the FE type include, for example, WPDyke & W.W.Dolan, “Field Emission”, Advance in Electron Physics, 8, 89 (1956), or CASpindt, “Physical Properties of Thin-Film Field Emission Cathodes with Molybdenium. Cones ”, J. Appl. Phys., 47, 5248 (1976).
[0008]
As a typical example of the element configuration of the FE type, FIG. A. A cross-sectional view of the element according to Spindt et al. Is shown. In this figure, 3010 is a substrate, 3011 is an emitter wiring made of a conductive material, 3012 is an emitter cone, 3013 is an insulating layer, and 3014 is a gate electrode. This element causes field emission from the tip of the emitter cone 3012 by applying an appropriate voltage between the emitter cone 3012 and the gate electrode 3014.
[0009]
Further, as another element configuration of the FE type, there is an example in which an emitter and a gate electrode are arranged on a substrate substantially parallel to the substrate plane, instead of the laminated structure as shown in FIG.
[0010]
Further, as an example of the MIM type, for example, CAMead, “Operation of tunnel-emission Devices”, J. Appl. Phys., 32, 646 (1961) and the like are known. A typical example of the MIM type element configuration is shown in FIG. This figure is a sectional view, in which 3020 is a substrate, 3021 is a lower electrode made of metal, 3022 is a thin insulating layer having a thickness of about 100 mm, and 3023 is an upper electrode made of a metal having a thickness of about 80 to 300 mm. is there.
[0011]
In the MIM type, an appropriate voltage is applied between the upper electrode 3023 and the lower electrode 3021 to cause electron emission from the surface of the upper electrode 3023.
[0012]
Since the above-described cold cathode device can obtain electron emission at a lower temperature than a hot cathode device, a heater for heating is not required. Therefore, the structure is simpler than that of the hot cathode device, and a fine device can be produced. Further, even if a large number of elements are arranged on the substrate at a high density, problems such as thermal melting of the substrate hardly occur. Further, unlike the case where the hot cathode element operates by heating of the heater, the response speed is slow. In the case of the cold cathode element, there is also an advantage that the response speed is fast.
[0013]
For this reason, research for applying cold cathode devices has been actively conducted.
[0014]
For example, the surface conduction electron-emitting device has an advantage that a large number of devices can be formed over a large area because the structure is particularly simple and easy to manufacture among the cold cathode devices. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 64-31332 by the present applicant, a method for arranging and driving a large number of elements has been studied.
[0015]
As for the application of surface conduction electron-emitting devices, for example, image forming apparatuses such as image display apparatuses and image recording apparatuses, charged beam sources, and the like have been studied.
[0016]
In particular, as an application to an image display device, for example, as disclosed in US Pat. No. 5,066,883, JP-A-2-257551 and JP-A-4-28137 by the present applicant, An image display device using a combination of a conductive emission element and a phosphor that emits light when irradiated with an electron beam has been studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have characteristics superior to those of other conventional image display devices. For example, it can be said that it is superior in that it does not require a backlight and has a wide viewing angle as compared with a liquid crystal display device that has been widespread in recent years.
[0017]
A method for driving a plurality of FE types in a row is disclosed, for example, in US Pat. No. 4,904,895 by the present applicant. As an example of applying the FE type to an image display device, for example, R.I. A flat panel display device reported by Meyer et al. Is known [R. Meyer: “Recent Development on Microtips Display at LETI”, Tech. Digest of 4th Int. Vacuum Microele-ctronics Conf., Nagahama, pp. 6- 9 (1991)].
[0018]
An example in which a large number of MIM types are arranged and applied to an image display device is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-55738 by the present applicant.
[0019]
Among the image forming apparatuses using the electron-emitting devices as described above, a flat-type display device with a small depth is attracting attention as a replacement for a CRT type display device because it is space-saving and lightweight.
[0020]
FIG. 22 is a perspective view showing an example of a display panel portion constituting a flat type image display device, and a part of the panel is cut away to show the internal structure.
[0021]
In the figure, reference numeral 3115 denotes a rear plate, 3116 denotes a side wall, and 3117 denotes a face plate. The rear plate 3115, the side wall 3116 and the face plate 3117 provide an envelope (airtight container) for maintaining the inside of the display panel in a vacuum. Forming.
[0022]
A substrate 3111 is fixed to the rear plate 3115, and N × M cold cathode elements 3112 are formed on the substrate 3111. N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. Further, the N × M cold cathode elements 3112 are wired by M row direction wirings 3113 and N column direction wirings 3114 as shown in FIG. A portion constituted by the substrate 3111, the cold cathode element 3112, the row direction wiring 3113, and the column direction wiring 3114 is referred to as a multi-electron beam source. In addition, an insulating layer (not shown) is formed between both the wirings in the row direction wiring 3113 and the column direction wiring 3114 so that electrical insulation is maintained.
[0023]
A phosphor film 3118 made of phosphor is formed on the lower surface of the face plate 3117, and phosphors (not shown) of three primary colors of red (R), green (G), and blue (B) are separately applied. Yes. Further, a black body (not shown) is provided between the color phosphors forming the phosphor film 3118, and a metal back 3119 made of Al or the like is formed on the surface of the phosphor film 3118 on the rear plate 3115 side. ing.
[0024]
Dx1 to Dxm and Dy1 to Dyn and Hv are electrical connection terminals having an airtight structure provided to electrically connect the display panel and an electric circuit (not shown). Dx1 to Dxm are electrically connected to the row direction wiring 3113 of the multi electron beam source, Dy1 to Dyn are electrically connected to the column direction wiring 3114 of the multi electron beam source, and Hv is electrically connected to the metal back 3119.
[0025]
The inside of the above airtight container is 10 ^-6 As the display area of the image display device is increased because the vacuum is maintained at about [Torr], a means for preventing the deformation or destruction of the rear plate 3115 and the face plate 3117 due to the pressure difference between the inside and the outside of the hermetic container is necessary. It becomes. The method of increasing the thickness of the rear plate 3115 and the face plate 3116 not only increases the weight of the image display device, but also causes image distortion and parallax when viewed from an oblique direction. On the other hand, in FIG. 22, a structural support (called a spacer or a rib) 3120 made of a relatively thin glass plate for supporting atmospheric pressure is provided. In this way, the space between the substrate 3111 on which the multi-beam electron source is formed and the face plate 3116 on which the fluorescent film 3118 is formed is normally maintained at sub millimeters to several millimeters, and the inside of the hermetic container is maintained at a high vacuum as described above. ing.
[0026]
The image display apparatus using the display panel described above emits electrons from each cold cathode element 3112 when a voltage is applied to each cold cathode element 3112 through the external terminals Dx1 to Dxm and Dy1 to Dyn. At the same time, a high voltage of several hundred [V] to several [kV] is applied to the metal back 3119 through the container outer terminal Hv to accelerate the emitted electrons and collide with the inner surface of the face plate 3117. As a result, the phosphors of the respective colors forming the fluorescent film 3118 are excited to emit light, and an image is displayed.
[0027]
[Problems to be solved by the invention]
As described above, an electron beam apparatus such as an image forming apparatus includes an envelope for maintaining a vacuum atmosphere inside the apparatus, an electron source disposed in the envelope, and an electron beam emitted from the electron source. The target includes an accelerating electrode for accelerating the target to be irradiated and an electron beam toward the target, and a support member (spacer) for supporting the atmospheric pressure applied to the envelope from the inside of the envelope. May be placed inside.
[0028]
The display panel of such an image display device has the following problems.
[0029]
First, there is a possibility that spacer charging is caused when a part of electrons emitted from the vicinity of the spacer hits the spacer or ions ionized by the action of the emitted electrons adhere to the spacer. Furthermore, there is a possibility that the electrons reaching the face plate are partly reflected and scattered, and a part of the electrons hits the spacer, thereby causing spacer charging. The electrons emitted from the cold cathode device due to the charging of the spacer are bent in the trajectory, reach a place different from the normal position on the phosphor, and the image near the spacer is distorted and displayed.
[0030]
In order to solve this problem, proposals have been made to remove the charge (hereinafter referred to as charge removal) so that a minute current flows through the spacer. There, a high resistance film is formed as a high resistance layer on the surface of the insulating spacer so that a minute current flows on the spacer surface.
However, the high resistance layer is caused by a problem of mechanical stability such as film peeling in a heat process at the time of assembling the image forming apparatus, a change in state due to surface oxidation, and diffusion of a material contained in the spacer material (for example, alkali element). There is a problem that chemical damage occurs, often causing a problem of characteristic deterioration.
[0031]
An object of the present invention is to provide an electron beam apparatus having a spacer in which a high resistance layer on the surface is mechanically and chemically stable.
[0032]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have determined that at least one of the electron source substrate and the face plate substrate has a coefficient of thermal expansion of 80 × 10 as a countermeasure against the above-described problems. ^-7 / ℃ to 90 × 10 ^-7 The spacer has a value between 75 ° C / 75 ° C ^-7 / ° C to 95 × 10 ^-7 It has been found that it is effective to use a ceramic material having a thermal expansion coefficient of / ° C. Moreover, it discovered that the ceramic which has these thermal expansion coefficients is realizable with the mixed baked material material which added the zirconia to the alumina. At this time, a desired thermal expansion coefficient is obtained by setting the weight mixing ratio of alumina and zirconia to a value between 70:30 and 10:90.
[0033]
Further, when the spacer substrate has an alkali or alkaline earth metal content of 0.1% or less, the influence on the high resistance film can be prevented.
[0034]
Furthermore, by treating the high resistance layer in advance at a temperature higher than the temperature at the time of assembling the spacer, it becomes possible to form a highly stable high resistance film in subsequent processes such as at the time of assembly.
[0035]
Ceramics generally have higher heat resistance than glass. This enables high-temperature processing by using ceramics as a spacer substrate during high resistance formation or subsequent heat treatment, and is stable with excellent mechanical strength such as thermal stability, chemical stability, and resistance to peeling. A high resistance film can be formed.
[0036]
In addition, the thermal expansion coefficient can be adjusted without adding an alkali element according to the configuration of the present invention. This can prevent deterioration of the high-resistance layer and prevent defects in the upper and lower connection portions of the spacer due to alkali diffusion.
[0037]
The present invention improves the above-mentioned drawbacks of conventional spacers and provides a spacer exhibiting excellent static elimination characteristics with excellent life characteristics.
[0038]
The electron beam apparatus of the present invention may have the following form.
[0039]
(1) In the electron beam apparatus, the electrode is an accelerating electrode for accelerating electrons emitted from the electron source, and an image emitted by irradiating the target with electrons emitted from the cold cathode device according to an input signal. Forming an image forming apparatus. In particular, an image display device in which the target is a phosphor is made.
[0040]
(2) The cold cathode device is a cold cathode device having a conductive film including an electron emitting portion between a pair of electrodes, and is particularly preferably a surface conduction electron-emitting device.
[0041]
{Circle around (3)} The electron source is an electron source arranged in a simple matrix having a plurality of cold cathode elements matrix-wired by a plurality of row direction wirings and a plurality of column direction wirings.
[0042]
(4) The electron source has a plurality of cold cathode element rows each having a plurality of cold cathode elements arranged in parallel connected at both ends (referred to as a row direction), and a direction perpendicular to the wiring (column direction). A control electrode (also referred to as a grid) disposed above the cold cathode device is used as a ladder-shaped electron source for controlling electrons from the cold cathode device.
[0043]
(5) Further, according to the idea of the present invention, the present invention is not limited to an image forming apparatus suitable for display, but as an alternative light source such as a light emitting diode of an optical printer composed of a photosensitive drum and a light emitting diode. The above-described image forming apparatus can also be used. At this time, by appropriately selecting the above-mentioned m row-directional wirings and n column-directional wirings, the present invention can be applied not only to a line-shaped light source but also to a two-dimensional light source. In this case, the image forming member is not limited to a material that directly emits light, such as a phosphor used in the following embodiments, and a member that forms a latent image by charging with electrons can also be used.
[0044]
Further, according to the idea of the present invention, the present invention can be applied to a case where a member to be irradiated with electrons emitted from an electron source is other than an image forming member such as a phosphor as in an electron microscope. . Therefore, the present invention can take the form of a general electron beam apparatus that does not specify the irradiated member.
[0045]
DETAILED DESCRIPTION OF THE INVENTION
Next, the configuration and manufacturing method of the display panel of the image display device to which the present invention is applied will be described with reference to specific examples.
[0046]
FIG. 1 is a perspective view of a display panel used in this embodiment, and a part of the panel is cut away to show the internal structure.
[0047]
In the figure, 1015 is a rear plate, 1016 is a side wall, 1017 is a face plate, and 1015 to 1017 form an airtight container for maintaining the inside of the display panel in a vacuum. When assembling an airtight container, it is necessary to seal the joints of each member in order to maintain sufficient strength and airtightness. For example, frit glass is applied to the joints, and in the air or in a nitrogen atmosphere, Celsius. Sealing was achieved by baking at 400 to 500 degrees for 10 minutes or more. A method for evacuating the inside of the hermetic container will be described later. The inside of the above airtight container is 10 ^-6 Since a vacuum of about [Torr] is maintained, a spacer 1020 is provided as an atmospheric pressure resistant structure for the purpose of preventing the airtight container from being destroyed by atmospheric pressure or unexpected impact. A substrate 1011 is fixed to the rear plate 1015, and N × M cold cathode elements 1012 are formed on the substrate. N and M are positive integers of 2 or more, and are appropriately set according to the target number of display pixels. For example, in a display device for the purpose of displaying high-definition television, it is desirable to set numbers of N = 3000 and M = 1000 or more. The N × M cold cathode elements are simply matrix-wired by M row-directional wirings 1013 and N column-directional wirings 1014. The portion composed of 1011 to 1014 is called a multi-electron beam source.
[0048]
The multi-electron beam source used in the image display apparatus of the present invention is not limited in the material, shape or manufacturing method of the cold cathode element as long as it is an electron source in which cold cathode elements are wired in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction electron-emitting device, FE type, or MIM type can be used.
[0049]
Next, the structure of a multi-electron beam source in which surface conduction electron-emitting devices (described later) are arranged as a cold cathode device on a substrate and wired in a simple matrix will be described.
[0050]
FIG. 6 is a plan view of the multi-electron beam source used in the display panel of FIG. On the substrate 1011, surface conduction electron-emitting devices similar to those shown in FIG. 4 described later are arranged, and these devices are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. An insulating layer (not shown) is formed between the electrodes at the intersecting portions of the row direction wiring electrodes 1013 and the column direction wiring electrodes 1014 so that electrical insulation is maintained.
[0051]
FIG. 5 shows a cross section taken along the line BB ′ of FIG.
[0052]
The multi-electron source having such a structure includes a row-direction wiring electrode 1013, a column-direction wiring electrode 1014, an inter-electrode insulating layer (not shown), and element electrodes 1102 and 1103 of surface conduction electron-emitting devices on a substrate in advance. After the conductive thin film 1104 was formed, each element was supplied through the row direction wiring electrode 1013 and the column direction wiring electrode 1014 to perform energization forming processing (described later) and energization activation processing (described later).
[0053]
In the present embodiment, the multi-electron beam source substrate 1011 is fixed to the rear plate 1015 of the hermetic container. However, if the multi-electron beam source substrate 1011 has sufficient strength, the hermetic container The multi-electron beam source substrate 1011 itself may be used as the rear plate.
[0054]
A fluorescent film 1018 is formed on the lower surface of the face plate 1017. Since this embodiment is a color display device, the phosphor film 1018 is coated with phosphors of three primary colors red, green and blue used in the field of CRT. For example, as shown in FIG. 17A, the phosphors of the respective colors are separately applied in stripes, and a black conductor 1010 is provided between the stripes of the phosphors. The purpose of providing the black conductor 1010 is to prevent the display color from shifting even if there is a slight shift in the irradiation position of the electron beam, or to prevent the reflection of external light and reduce the display cost last. For example, preventing the phosphor film from being charged up by an electron beam. For the black conductor 1010, graphite is used as a main component, but other materials may be used as long as they are suitable for the above purpose.
[0055]
Further, the method of separately applying the phosphors of the three primary colors is not limited to the stripe arrangement shown in FIG. 17 (a). For example, a delta arrangement as shown in FIG. It may be an array.
[0056]
Note that when a monochrome display panel is formed, a monochromatic phosphor material may be used for the phosphor film 1018, and a black conductive material is not necessarily used.
[0057]
Further, a metal back 1019 known in the field of CRT is provided on the surface of the fluorescent film 1018 on the rear plate side. The purpose of providing the metal back 1019 is to improve the light utilization rate by specularly reflecting a part of the light emitted from the fluorescent film 1018, to protect the fluorescent film 1018 from the collision of negative ions, and the electron beam acceleration voltage. For example, to act as an electrode for applying a voltage, or to act as a conductive path for excited electrons in the fluorescent film 1018. The metal back 1019 was formed by forming a fluorescent film 1018 on the face plate substrate 1017, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon. Note that when a low-voltage phosphor material is used for the phosphor film 1018, the metal back 1019 may not be used.
[0058]
Although not used in this embodiment, a transparent electrode made of, for example, ITO is provided between the face plate substrate 1017 and the fluorescent film 1018 for the purpose of applying an acceleration voltage and improving the conductivity of the fluorescent film. May be.
[0059]
FIG. 2 is a schematic cross-sectional view taken along the line AA ′ of FIG. 1, and the numbers of the respective parts correspond to FIG. The spacer 1020 has a high resistance film 11 as a first layer for the purpose of preventing charging on the surface of the insulating member 1. In addition, low resistance films 3a and 3b are provided on a part of the contact surface and side surface of the spacer facing the inside of the face plate 1017 (metal back 1019 and the like) and the surface of the substrate 1011 (row direction wiring 1013 or column direction wiring 1014). .
[0060]
The spacers are arranged in the necessary number and at the necessary intervals to achieve the above object, and are fixed to the inside of the face plate and the surface of the substrate 1011 by the bonding material 1041.
[0061]
The high resistance film 11 is formed on at least the surface of the insulating member 1 exposed in the vacuum in the airtight container, and the low resistance films 3a, 3b, 5a on the spacer 1020 are formed. 5b and the bonding material 1041 are electrically connected to the inside of the face plate 1017 (metal back 1019 and the like) and the surface of the substrate 1011 (row direction wiring 1013 or column direction wiring 1014). In the embodiment described here, the spacer 1020 has a thin plate shape, and the spacer 1020 is arranged in parallel to the row direction wiring 1013 and is electrically connected to the row direction wiring 1013.
[0062]
The spacer substrate 1 has an electrical resistance sufficient to withstand a high voltage applied between the row direction wiring 1013 and the column direction wiring 1014 on the substrate 1011 and the metal back 1019 on the inner surface of the face plate 1017. It is necessary to have conductivity sufficient to prevent charging of the surface of 1. The spacer substrate 1 is preferably an insulating member, and preferably has a thermal expansion coefficient close to that of the member forming the hermetic container and the substrate 1011.
[0063]
The high resistance film 11 constituting the spacer 1020 has a current obtained by dividing the acceleration voltage Va applied to the high potential side face plate 1017 (metal back 1019 or the like) by the resistance value Rs of the high resistance film 11 as an antistatic film. Will be washed away. Therefore, the resistance value Rs of the spacer is set in a desirable range from antistatic and power consumption. From the viewpoint of antistatic, sheet resistance R / □ is 10 ¹² It is preferable that it is below Ω / □. 10 to obtain sufficient antistatic effect ¹¹ More preferably less than Ω / □. The lower limit of the sheet resistance depends on the spacer shape and the voltage applied between the spacers. ^Five It is preferable that it is Ω / □ or more.
[0064]
The thickness t of the antistatic film formed on the insulating material is preferably in the range of 10 nm to 1 μm. Although it varies depending on the surface energy of the material, adhesion to the substrate, and substrate temperature, a thin film of 10 nm or less is generally formed in an island shape, and its resistance is unstable and reproducibility is poor. On the other hand, when the film thickness t is 1 μm or more, the film stress increases, the risk of film peeling increases, and the film formation time increases, resulting in poor productivity. Therefore, the film thickness is desirably 50 to 500 nm.
[0065]
The sheet resistance R / □ is ρ / t, and the specific resistance ρ of the antistatic film is 0.1 [Ωcm] to 10 to 10 from the preferable range of the sheet resistance R / □ and the film thickness t described above. ⁸ [Ωcm] is preferred. Furthermore, in order to realize a more preferable range of sheet resistance and film thickness, ρ is 10 ² Thru 10 ⁶ It is good to use Ωcm. As described above, the temperature of the spacer rises when a current flows through the antistatic film formed thereon or when the entire display generates heat during operation. When the resistance temperature coefficient of the antistatic film is a large negative value, the resistance value decreases when the temperature rises, the current flowing through the spacer increases, and the temperature rises further. The current continues to increase until it exceeds the power supply limit. The value of the resistance temperature coefficient at which such a current runaway occurs is empirically a negative value and the absolute value is 1% or more. That is, the resistance temperature coefficient of the antistatic film is desirably less than −1%.
[0066]
As a material of the high resistance film 11 having antistatic properties, for example, a metal oxide such as tin oxide or nickel oxide can be used.
[0067]
As another material of the high resistance film 11 having antistatic properties, the nitride of aluminum and transition metal alloy can control the resistance value in a wide range from a good conductor to an insulator by adjusting the composition of the transition metal. It is a suitable material. Furthermore, it is a stable material with little change in resistance value in the manufacturing process of the display device described later. In addition, the temperature coefficient of resistance is less than -1%, and it is a material that is practically easy to use. Examples of the transition metal element include Ti, Cr, Ta and the like.
[0068]
The alloy nitride film is formed on the insulating member by thin film forming means such as sputtering, reactive sputtering in a nitrogen gas atmosphere, electron beam vapor deposition, ion plating, or ion assist vapor deposition. The metal oxide film can also be produced by a similar thin film formation method, but in this case, oxygen gas is used instead of nitrogen gas. In addition, a metal oxide film can be formed by a CVD method or an alkoxide coating method. The carbon film is produced by vapor deposition, sputtering, CVD, or plasma CVD. In particular, when producing amorphous carbon, the atmosphere during film formation should contain hydrogen or be used as a film formation gas. Use hydrocarbon gas.
[0069]
The low resistance films 3a and 3b constituting the spacer 1020 electrically connect the high resistance film 11 to the face plate 1017 (metal back 1019 and the like) on the high potential side and the substrate 1011 (wirings 1013 and 1014 etc.) on the low potential side. In the following, the name of an intermediate electrode layer (intermediate layer) is also used. The intermediate electrode layer (intermediate layer) can have a plurality of functions listed below.
[0070]
(1) The high resistance film 11 is electrically connected to the face plate 1017 and the substrate 1011.
[0071]
As already described, the high-resistance film 11 is provided for the purpose of preventing charging on the surface of the spacer 1020. However, the high-resistance film 11 is applied to the face plate 1017 (metal back 1019 or the like) and the substrate 1011 (wiring 1013). 1014) directly or via the bonding material 1041, a large contact resistance is generated at the interface of the connection portion, and there is a possibility that charges generated on the spacer surface cannot be removed quickly. In order to avoid this, a low-resistance intermediate layer is provided on the contact surface or side surface of the spacer 1020 that contacts the face plate 1017, the substrate 1011, and the bonding material 1041.
[0072]
(2) The potential distribution of the high resistance film 11 is made uniform.
[0073]
Electrons emitted from the cold cathode element 1012 form an electron trajectory according to a potential distribution formed between the face plate 1017 and the substrate 1011. In order to prevent disturbance of the electron trajectory in the vicinity of the spacer 1020, it is necessary to control the potential distribution of the high resistance film 11 over the entire region. When the high-resistance film 11 is connected to the face plate 1017 (metal back 1019, etc.) and the substrate 1011 (wirings 1013, 1014, etc.) directly or via the bonding material 1041, the connection state is uneven due to the contact resistance at the interface of the connection portion. May occur, and the potential distribution of the high resistance film 11 may deviate from a desired value. In order to avoid this, a low resistance intermediate layer is provided in the entire length region of the spacer end portion (contact surface 3 or side surface portion 5) where the spacer 1020 contacts the face plate 1017 and the substrate 1011. By applying a potential, the potential of the entire high resistance film 11 can be controlled.
[0074]
(3) Control the orbit of emitted electrons.
[0075]
Electrons emitted from the cold cathode element 1012 form an electron trajectory according to a potential distribution formed between the face plate 1017 and the substrate 1011. With respect to electrons emitted from the cold cathode device in the vicinity of the spacer, restrictions (wiring, change of device position, etc.) associated with the installation of the spacer may occur. In such a case, in order to form an image without distortion or unevenness, it is necessary to control the trajectory of the emitted electrons to irradiate the desired position on the face plate 1017 with electrons. By providing a low resistance intermediate layer on the side surface portion 5 of the face plate 1017 and the substrate 1011 in contact with the surface plate 1017, the potential distribution in the vicinity of the spacer 1020 can have desired characteristics and the trajectory of emitted electrons can be controlled. I can do it.
[0076]
For the low resistance films 3a and 3b, a material having a sufficiently low resistance value as compared with the high resistance film 11 may be selected, and metals such as Ni, Cr, Au, Mo, W, Pt, Ti, Al, Cu, and Pd are used. Or alloys, and Pd, Ag, Au, RuO ₂ , Pd-Ag and other printed conductors composed of metal or metal oxide and glass, or In ₂ O _Three -SnO ₂ The material is appropriately selected from a transparent conductor such as polysilicon and a semiconductor material such as polysilicon.
[0077]
The bonding material 1041 having conductivity needs to have conductivity so that the spacer 1020 is electrically connected to the row direction wiring 1013 and the metal back 1019. That is, a frit glass to which a conductive adhesive, metal particles, or a conductive filler is added is suitable.
[0078]
In FIG. 1, Dx1 to Dxm, Dy1 to Dyn, and Hv are electrical connection terminals having an airtight structure provided to electrically connect the display panel and an electric circuit (not shown). Dx1 to Dxm are electrically connected to the row-direction wiring 1013 of the multi-electron beam source, Dy1 to Dyn are electrically connected to the column-direction wiring 1014 of the multi-electron beam source, and Hv is electrically connected to the metal back 1019 of the face plate.
[0079]
Further, in order to evacuate the inside of the hermetic container, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is ^-7 The air is exhausted to a degree of vacuum of [Torr]. Thereafter, the exhaust pipe is sealed. In order to maintain the degree of vacuum in the hermetic container, a getter film (not shown) is formed at a predetermined position in the hermetic container immediately before or after sealing. A getter film is a film formed by, for example, heating and vapor-depositing a getter material mainly composed of Ba by a heater or high-frequency heating, and the inside of an airtight container is 1 × 10 6 by the adsorption action of the getter film. ^-Five To 1 × 10 ^-7 The degree of vacuum is maintained at [Torr].
[0080]
In the image display device using the display panel described above, electrons are emitted from each cold cathode element 1012 when a voltage is applied to each cold cathode element 1012 through the external terminals Dx1 to Dxm and Dy1 to Dyn. At the same time, a high voltage of several hundred [V] to several [kV] is applied to the metal back 1019 through the container outer terminal Hv to accelerate the emitted electrons and collide with the inner surface of the face plate 1017. Thereby, the phosphors of the respective colors forming the fluorescent film 1018 are excited to emit light, and an image is displayed.
[0081]
Usually, the applied voltage to the surface conduction electron-emitting device 1012 of the present invention, which is a cold cathode device, is about 12 to 16 [V], and the distance d between the metal back 1019 and the cold cathode device 1012 is 8 from 0.1 [mm]. The voltage between the metal back 1019 and the cold cathode element 1012 is about 0.1 [kV] to about 10 [kV].
[0082]
The basic configuration and manufacturing method of the display panel according to the embodiment of the present invention and the outline of the image display device have been described above.
[0083]
Next, the manufacturing method of the multi electron beam source used for the display panel of the embodiment will be described. The multi-electron beam source used in the image display apparatus of the present invention is not limited in the material, shape or manufacturing method of the cold cathode element as long as it is an electron source in which cold cathode elements are wired in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction electron-emitting device, FE type, or MIM type can be used.
[0084]
However, a display conduction type emitting element is particularly preferable among these cold cathode elements under a situation where a display device having a large display screen and a low price is required. That is, in the FE type, the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics, and thus an extremely accurate manufacturing technique is required. This achieves a large area and a reduction in manufacturing cost. This is a disadvantageous factor. Further, in the MIM type, it is necessary to make the insulating layer and the upper electrode thin and uniform, but this is also a disadvantageous factor in achieving a large area and a reduction in manufacturing cost. In that respect, since the surface conduction electron-emitting device is relatively simple to manufacture, it is easy to increase the area and reduce the manufacturing cost. Further, the inventors have found that among the surface conduction electron-emitting devices, those in which the electron emission portion or its peripheral portion is formed of a fine particle film are particularly excellent in electron emission characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron beam source of a high-luminance and large-screen image display device. Therefore, in the display panel of the above embodiment, a surface conduction electron-emitting device in which the electron emission portion or its peripheral portion is formed of a fine particle film is used. First, the basic configuration, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described, and then the structure of a multi-electron beam source in which a number of devices are wired in a simple matrix will be described.
[0085]
[Suitable Device Configuration and Manufacturing Method for Surface Conduction Emitting Device]
There are two types of typical structures of the surface conduction electron-emitting device in which the electron emission portion or the peripheral portion thereof is formed of a fine particle film, a planar type and a vertical type.
[0086]
[Plane type surface conduction electron-emitting devices]
First, the device configuration and manufacturing method of a planar surface conduction electron-emitting device will be described.
[0087]
FIG. 4 is a plan view (a) and a cross-sectional view (b) for explaining the configuration of a planar surface conduction electron-emitting device. In the figure, 1011 is a substrate, 1102 and 1103 are element electrodes, 1104 is a conductive thin film, 1105 is an electron emission portion formed by energization forming treatment, and 1113 is a thin film formed by energization activation treatment.
[0088]
The device electrodes 1102 and 1103 provided on the substrate 1011 so as to face the substrate surface in parallel are formed of a conductive material. For example, metals such as Ni, Cr, Au, Mo, W, Pt, Ti, Cu, Pd, Ag, etc., or alloys of these metals, or In ₂ O _Three -SnO ₂ A material may be appropriately selected from metal oxides such as silicon, semiconductors such as polysilicon, and the like. In order to form the electrode, it can be easily formed by using a combination of a film forming technique such as vacuum deposition and a patterning technique such as photolithography and etching, but it can be formed by using other methods (for example, a printing technique). No problem.
[0089]
The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device. In general, the electrode interval L is usually designed by selecting an appropriate numerical value from a range of several hundreds to several hundreds of μm, and among them, it is preferably several μm to several tens of μm for application to a display device. Range. For the thickness d of the device electrode, an appropriate value is usually selected from the range of several hundred to several μm.
[0090]
A fine particle film is used for the conductive thin film 1104. The fine particle film described here refers to a film (including an island-like aggregate) containing a large number of fine particles as a constituent element. If the fine particle film is examined microscopically, usually, a structure in which individual fine particles are arranged apart from each other, a structure in which the fine particles are adjacent to each other, or a structure in which the fine particles overlap each other is observed.
[0091]
The particle diameter of the fine particles used in the fine particle film is in the range of several to several thousand, and the preferable one is in the range of 10 to 200. The film thickness of the fine particle film is appropriately set in consideration of various conditions as described below. That is, the conditions necessary for making a good electrical connection with the element electrode 1102 or 1103, the conditions necessary for performing the energization forming described later, and the electric resistance of the fine particle film itself to an appropriate value described later. The conditions necessary for Specifically, it is set within the range of several to thousands of tons, but is preferably between 10 to 500 tons.
[0092]
Examples of materials that can be used to form the fine particle film include Pd, Pt, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, Ta, W, and Pb. Metals such as PdO, SnO ₂ , In ₂ O _Three , PbO, Sb ₂ O _Three , And other oxides, and HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB _Four , GdB _Four , Borides such as TiC, ZrC, HfC, TaC, SiC, WC, etc., nitrides including TiN, ZrN, HfN, etc., Si, Ge, etc. And the like, carbon, and the like, which are appropriately selected from these.
[0093]
As described above, the conductive thin film 1104 is formed of a fine particle film. ^Three To 10 ⁷ It was set to be included in the range of [Ohm / □].
[0094]
Note that it is desirable that the conductive thin film 1104 and the element electrodes 1102 and 1103 be electrically connected to each other, and thus a structure in which a part of the conductive thin film 1104 and the element electrodes 1102 and 1103 overlap each other is employed. In the example of FIG. 4, the overlapping is performed in the order of the substrate, the device electrode, and the conductive thin film from the bottom. However, in some cases, the substrate, the conductive thin film, and the device electrode are stacked in this order. No problem.
[0095]
In addition, the electron emission portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has an electrical property higher than that of the surrounding conductive thin film. The crack is formed by performing an energization forming process to be described later on the conductive thin film 1104. There are cases where fine particles having a particle diameter of several to several hundreds are arranged in the crack. In addition, since it is difficult to accurately and accurately illustrate the actual position and shape of the electron emission portion, it is schematically shown in FIG.
[0096]
The thin film 1113 is a thin film made of carbon or a carbon compound, and covers the electron emission portion 1105 and the vicinity thereof. The thin film 1113 is formed by performing an energization activation process described later after the energization forming process.
[0097]
The thin film 1113 is one of single crystal graphite, polycrystalline graphite, amorphous carbon, or a mixture thereof, and the film thickness is 500 [Å] or less, but is preferably 300 [Å] or less. preferable. In addition, since it is difficult to accurately illustrate the position and shape of the actual thin film 1113, it is schematically shown in FIG. In addition, in the plan view (a), an element from which a part of the thin film 1113 (the upper layer part of 1105) is removed is shown.
[0098]
The basic configuration of a preferable element has been described above. In the embodiment, the following element is used.
[0099]
That is, blue plate glass was used for the substrate 1011 and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrode was 1000 [Å], and the electrode interval L was 2 [μm].
[0100]
Pd or PdO was used as the main material of the fine particle film, the fine particle film had a thickness of about 100 [Å] and a width W of 100 [μm].
[0101]
Next, a preferred method for manufacturing a planar surface conduction electron-emitting device will be described.
[0102]
FIGS. 9A to 9E are cross-sectional views for explaining the manufacturing process of the surface conduction electron-emitting device, and the notations of the respective members are the same as those in FIG.
[0103]
1) First, device electrodes 1102 and 1103 are formed on a substrate 1011 as shown in FIG.
[0104]
In the formation, the substrate 1011 is sufficiently washed in advance with a detergent, pure water, and an organic solvent, and then a material for the element electrode is deposited. (For example, a vacuum film forming technique such as a vapor deposition method or a sputtering method may be used as a deposition method.) Thereafter, the deposited electrode material is patterned using a photolithography / etching technique, and (a) is formed. The pair of element electrodes (1102 and 1103) shown are formed.
[0105]
2) Next, a conductive thin film 1104 is formed as shown in FIG.
[0106]
In forming the film, first, an organic metal solution is applied to the substrate (a), dried, heated and fired to form a fine particle film, and then patterned into a predetermined shape by photolithography and etching. Here, the organometallic solution is a solution of an organometallic compound whose main element is a fine particle material used for the conductive thin film. (Specifically, Pd is used as the main element in this embodiment. Further, in this embodiment, the dipping method is used as the coating method, but other methods such as spinner method and spray method may be used. )
In addition, as a method for forming a conductive thin film made of a fine particle film, for example, a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, or the like other than the method by applying an organometallic solution used in this embodiment is used. Sometimes used.
[0107]
3) Next, as shown in FIG. 5C, an appropriate voltage is applied between the forming power supply 1110 between the device electrodes 1102 and 1103, and energization forming processing is performed to form the electron emission portion 1105.
[0108]
The energization forming process is a process in which a conductive thin film 1104 made of a fine particle film is energized, and a part thereof is appropriately destroyed, deformed, or altered, and changed into a structure suitable for electron emission. That is. In a portion of the conductive thin film made of the fine particle film that has been changed to a structure suitable for electron emission (that is, the electron emission portion 1105), an appropriate crack is formed in the thin film. Note that the electrical resistance measured between the device electrodes 1102 and 1103 significantly increases after the formation, compared to before the electron emission portion 1105 is formed.
[0109]
In order to describe the energization method in more detail, FIG. 10 shows an example of an appropriate voltage waveform applied from the forming power supply 1110. When forming a conductive thin film made of a fine particle film, a pulsed voltage is preferable. In this embodiment, a triangular wave pulse having a pulse width T1 is continuously applied at a pulse interval T2 as shown in FIG. Applied. At that time, the peak value Vpf of the triangular wave pulse was boosted sequentially. Further, a monitor pulse Pm for monitoring the formation state of the electron emission portion 1105 was inserted between the triangular wave pulses at an appropriate interval, and the current flowing at that time was measured by an ammeter 1111.
[0110]
In the present embodiment, for example, 10 ^-Five In a vacuum atmosphere of about [torr], for example, the pulse width T1 was set to 1 [msec], the pulse interval T2 was set to 10 [msec], and the peak value Vpf was increased by 0.1 [V] for each pulse. Then, every time 5 pulses of the triangular wave were applied, the monitor pulse Pm was inserted at a rate of once. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. The electric resistance between the device electrodes 1102 and 1103 is 1 × 10 ⁶ At the stage when [Ω] is reached, that is, when the monitor pulse is applied, the current measured by the ammeter 1111 is 1 × 10 ^-7 [A] The energization for the forming process was terminated at the following stage.
[0111]
The above method is a preferable method for the surface conduction electron-emitting device of the present embodiment. For example, when the design of the surface conduction electron-emitting device such as the material and film thickness of the fine particle film or the element electrode interval L is changed. Accordingly, it is desirable to change the energization conditions accordingly.
[0112]
4) Next, as shown in FIG. 9D, an appropriate voltage is applied between the activation power supply 1112 between the device electrodes 1102 and 1103, and the energization activation process is performed to improve the electron emission characteristics. Do.
[0113]
The energization activation process is a process of energizing the electron emission portion 1105 formed by the energization forming process under appropriate conditions and depositing carbon or a carbon compound in the vicinity thereof. (In the figure, a deposit made of carbon or a carbon compound is schematically shown as the member 1113.) Note that, by conducting the energization activation process, the emission current at the same applied voltage is typically compared to before the conducting. Specifically, it can be increased 100 times or more.
[0114]
Specifically, 10 ^-Four Thru 10 ^-Five By periodically applying a voltage pulse in a vacuum atmosphere within the range of [Torr], carbon or a carbon compound originating from an organic compound present in the vacuum atmosphere is deposited. The deposit 1113 is one of single crystal graphite, polycrystalline graphite, amorphous carbon, or a mixture thereof, and the film thickness is 500 [Å] or less, more preferably 300 [３００] or less.
[0115]
In order to describe the energization method in more detail, FIG. 11A shows an example of an appropriate voltage waveform applied from the activation power supply 1112. In this embodiment, the energization activation process is performed by periodically applying a rectangular wave having a constant voltage. Specifically, the rectangular wave voltage Vac is 14 [V] and the pulse width T3 is 1 [msec. The pulse interval T4 was 10 [msec]. The energization conditions described above are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, it is desirable to change the conditions accordingly.
[0116]
Reference numeral 1114 shown in FIG. 9D denotes an anode electrode for capturing the emission current Ie emitted from the surface conduction electron-emitting device, to which a DC high voltage power source 1115 and an ammeter 1116 are connected. (When the activation process is performed after the substrate 1011 is incorporated in the display panel, the phosphor screen of the display panel is used as the anode electrode 1114.) While the voltage is applied from the activation power supply 1112, the current is applied. The emission current Ie is measured by the total 1116 to monitor the progress of the energization activation process, and the operation of the activation power supply 1112 is controlled. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG. 11 (b). When a pulse voltage is applied from the activation power supply 1112, the emission current Ie increases with time, but eventually becomes saturated. Almost no increase. As described above, when the emission current Ie is almost saturated, the voltage application from the activation power supply 1112 is stopped, and the energization activation process is ended.
[0117]
The energization conditions described above are preferable conditions for the surface conduction electron-emitting device of the present embodiment, and when the design of the surface conduction electron-emitting device is changed, it is desirable to change the conditions accordingly.
[0118]
As described above, the planar surface conduction electron-emitting device shown in FIG. 9E was manufactured.
[0119]
[Vertical surface conduction electron-emitting devices]
Next, another typical configuration of the surface conduction electron-emitting device in which the electron emission portion or its periphery is formed of a fine particle film, that is, the configuration of a vertical surface conduction electron-emitting device will be described.
[0120]
FIG. 7 is a schematic cross-sectional view for explaining a vertical basic configuration, in which 1201 is a substrate, 1202 and 1203 are element electrodes, 1206 is a step forming member, and 1204 is a conductive film using a fine particle film. 1205 is an electron emission portion formed by energization forming treatment, and 1213 is a thin film formed by energization activation treatment.
[0121]
The vertical type is different from the planar type described above in that one of the element electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 covers the side surface of the step forming member 1206. There is in point. Therefore, the element electrode interval L in the planar type in FIG. 4 is set as the step height Ls of the step forming member 1206 in the vertical type. For the substrate 1201, the device electrodes 1202 and 1203, and the conductive thin film 1204 using a fine particle film, the materials listed in the description of the planar type can be used similarly. Further, the step forming member 1206 includes, for example, SiO. ₂ An electrically insulating material such as
[0122]
Next, a method for manufacturing a vertical surface conduction electron-emitting device will be described. 12A to 12F are cross-sectional views for explaining the manufacturing process, and the notation of each member is the same as in FIG.
[0123]
1) First, as shown in FIG. 12A, an element electrode 1203 is formed on a substrate 1201.
[0124]
2) Next, as shown in FIG. 2B, an insulating layer for forming a step forming member is laminated. For example, the insulating layer is made of SiO. ₂ May be laminated by sputtering, but other film forming methods such as vacuum deposition and printing may be used.
[0125]
3) Next, as shown in FIG. 3C, the device electrode 1202 is formed on the insulating layer.
[0126]
4) Next, as shown in FIG. 4D, a part of the insulating layer is removed using, for example, an etching method to expose the device electrode 1203.
[0127]
5) Next, as shown in FIG. 5E, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the planar type, for example, a film forming technique such as a coating method may be used.
[0128]
6) Next, as in the case of the planar type, an energization forming process is performed to form an electron emission portion. (The same process as the planar energization forming process described with reference to FIG. 9C may be performed.)
7) Next, as in the case of the planar type, a current activation process is performed to deposit carbon or a carbon compound in the vicinity of the electron emission portion. (A process similar to the planar energization activation process described with reference to FIG. 9D may be performed.)
As described above, the vertical surface conduction electron-emitting device shown in FIG.
[0129]
[Characteristics of surface conduction electron-emitting devices used in display devices]
The device structure and manufacturing method of the planar and vertical surface conduction electron-emitting devices have been described above. Next, the characteristics of the devices used in the display device will be described.
[0130]
FIG. 8 shows typical examples of (emission current Ie) vs. (element applied voltage Vf) characteristics and (element current If) vs. (element applied voltage Vf) characteristics of the elements used in the display device. The emission current Ie is remarkably smaller than the device current If and is difficult to show on the same scale, and these characteristics are changed by changing design parameters such as the size and shape of the device. Therefore, the two characteristics are shown in arbitrary units.
[0131]
The element used in the display device has the following three characteristics with respect to the emission current Ie.
[0132]
First, when a voltage greater than a certain voltage (referred to as a threshold voltage Vth) is applied to the device, the emission current Ie increases rapidly. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current Ie is almost not increased. Not detected.
[0133]
That is, it is a nonlinear element having a clear threshold voltage Vth with respect to the emission current Ie.
[0134]
Second, since the emission current Ie changes depending on the voltage Vf applied to the device, the magnitude of the emission current Ie can be controlled by the voltage Vf.
[0135]
Third, since the response speed of the current Ie emitted from the element is high with respect to the voltage Vf applied to the element, the amount of electrons emitted from the element can be controlled by the length of time for which the voltage Vf is applied.
[0136]
Due to the above characteristics, the surface conduction electron-emitting device can be suitably used for a display device. For example, in a display device in which a large number of elements are provided corresponding to the pixels of the display screen, display can be performed by sequentially scanning the display screen by using the first characteristic. That is, a voltage equal to or higher than the threshold voltage Vth is appropriately applied to the driven element according to the desired light emission luminance, and a voltage lower than the threshold voltage Vth is applied to the non-selected element. By sequentially switching the elements to be driven, it is possible to display by sequentially scanning the display screen.
[0137]
Further, by using the second characteristic or the third characteristic, the light emission luminance can be controlled, so that gradation display can be performed.
[0138]
[Structure of multi-electron beam source with multiple elements in simple matrix wiring]
Next, the structure of a multi-electron beam source in which the above-described surface conduction electron-emitting devices are arranged on a substrate and simple matrix wiring is described.
[0139]
FIG. 6 is a plan view of the multi-electron beam source used in the display panel of FIG. On the substrate, surface conduction electron-emitting devices similar to those shown in FIG. 4 are arranged, and these devices are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. In the portion where the row direction wiring electrode 1003 and the column direction wiring electrode 1004 intersect, an insulating layer (not shown) is formed between the electrodes, and electrical insulation is maintained.
[0140]
FIG. 5 shows a cross section taken along the line BB ′ of FIG.
[0141]
The multi-electron source having such a structure includes a row-direction wiring electrode 1013, a column-direction wiring electrode 1014, an inter-electrode insulating layer (not shown), and an element electrode and a conductive thin film of a surface conduction electron-emitting device on a substrate in advance. Then, as described above, power was supplied to each element through the row direction wiring electrode 1013 and the column direction wiring electrode 1014 to perform energization forming processing and energization activation processing.
[0142]
FIG. 13 is a block diagram showing a schematic configuration of a drive circuit for performing television display based on NTSC television signals. In the figure, a display panel 1701 corresponds to the display panel described above, and is manufactured and operated as described above. Further, the scanning circuit 1702 scans the display line, and the control circuit 1703 generates a signal and the like input to the scanning circuit. The shift register 1704 shifts the data for each line, and the line memory 1705 inputs the data for one line from the shift register 1704 to the modulation signal generator 1707. A synchronization signal separation circuit 1706 separates the synchronization signal from the NTSC signal.
[0143]
Hereinafter, functions of each part of the apparatus of FIG. 13 will be described in detail.
[0144]
First, the display panel 1701 is connected to an external electric circuit through terminals Dx1 to Dxm, terminals Dy1 to Dyn, and a high voltage terminal Hv. Among these, the terminals Dx1 to Dxm sequentially drive a multi-electron beam source provided in the display panel 1701, that is, cold cathode elements arranged in a matrix of m rows and n columns, one row (n elements) at a time. Then, a scanning signal for applying is applied. On the other hand, modulation signals for controlling the output electron beams of n elements for one row selected by the scanning signal are applied to the terminals Dy1 to Dyn. The high voltage terminal Hv is supplied with a DC voltage of, for example, 5 [kV] from the DC voltage source Va, which is sufficient to excite the phosphor with the electron beam output from the multi-electron beam source. This is the acceleration voltage for applying energy.
[0145]
Next, the scanning circuit 1702 will be described. The circuit includes m switching elements (schematically shown by S1 to Sm in the figure), and each switching element has an output voltage of a DC voltage source Vx or 0 [V] ( Any one of (ground level) is selected and electrically connected to terminals Dx1 to Dxm of the display panel 1701. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 1703. In practice, however, it can be easily configured by combining switching elements such as FETs. . The DC voltage source Vx outputs a constant voltage so that the drive voltage applied to the element not scanned based on the characteristics of the electron-emitting device illustrated in FIG. 8 is equal to or lower than the electron-emitting threshold voltage Vth voltage. It is set to do.
[0146]
The control circuit 1703 has a function of matching the operations of the respective units so that appropriate display is performed based on an image signal input from the outside. Based on a synchronization signal Tsync sent from a synchronization signal separation circuit 1706 described below, Tscan, Tsft, and Tmry control signals are generated for each unit. The synchronization signal separation circuit 1706 is a circuit for separating a synchronization signal component and a luminance signal component from an NTSC television signal input from the outside. The synchronization signal separated by the synchronization signal separation circuit 1706 is composed of a vertical synchronization signal and a horizontal synchronization signal as is well known, but is shown here as a Tsync signal for convenience of explanation. On the other hand, the luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience, and this signal is input to the shift register 1704.
[0147]
The shift register 1704 is for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and operates based on the control signal Tsft sent from the control circuit 1703. . In other words, the control signal Tsft can be rephrased as a shift clock of the shift register 1704. Data for one line (corresponding to drive data for n electron-emitting devices) subjected to serial / parallel conversion is output from the shift register 1704 as n signals Id1 to Idn.
[0148]
The line memory 1705 is a storage device for storing data for one line of an image for a necessary time, and appropriately stores the contents of Id1 to Idn according to a control signal Tmry sent from the control circuit 1703. The stored contents are output as I ′d 1 to I′dn and input to the modulation signal generator 1707.
[0149]
The modulation signal generator 1707 is a signal source for appropriately driving and modulating each of the electron-emitting devices 1012 according to each of the image data I′d1 to I′dn, and the output signals thereof are terminals Doy1 to Doyn. And applied to the electron-emitting devices 1012 in the display panel 1701.
[0150]
As described with reference to FIG. 8, the surface conduction electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, there is a clear threshold voltage Vth for electron emission (8 [V] in the case of a surface conduction electron-emitting device described later), and electron emission occurs only when a voltage equal to or higher than the threshold Vth is applied. Further, for a voltage equal to or higher than the electron emission threshold, the emission current Ie also changes according to the voltage change as shown in the graph of FIG. For this reason, when a pulse voltage is applied to the element, for example, no electron emission occurs even when a voltage equal to or lower than the electron emission threshold Vth is applied, but when a voltage equal to or higher than the electron emission threshold Vth is applied, the surface An electron beam is output from the conductive emission element. At that time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. Further, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.
[0151]
Therefore, a voltage modulation method, a pulse width modulation method, or the like can be adopted as a method for modulating the electron-emitting device in accordance with the input signal. When implementing the voltage modulation method, a voltage modulation method circuit is used as the modulation signal generator 1707, which generates a voltage pulse of a certain length and appropriately modulates the peak value of the pulse according to the input data. be able to. Further, when implementing the pulse width modulation method, the modulation signal generator 1707 generates a pulse pulse having a constant peak value, and appropriately modulates the width of the voltage pulse according to the input data. A circuit of the type can be used.
[0152]
The shift register 1704 and the line memory 1705 can be either a digital signal type or an analog signal type. That is, it is only necessary to perform serial / parallel conversion and storage of the image signal at a predetermined speed.
[0153]
When the digital signal system is used, it is necessary to convert the output signal DATA of the synchronization signal separation circuit 1706 into a digital signal. For this purpose, an A / D converter may be provided at the output portion of the synchronization signal separation circuit 1706. . In this connection, the circuit used in the modulation signal generator is slightly different depending on whether the output signal of the line memory 1705 is a digital signal or an analog signal. That is, in the case of a voltage modulation method using a digital signal, for example, a D / A conversion circuit is used as the modulation signal generator 1707, and an amplifier circuit or the like is added as necessary. In the case of the pulse width modulation method, a modulation signal generator 1707 includes, for example, a high-speed oscillator and a counter that counts the wave number output from the oscillator, and a comparator that compares the output value of the counter with the output value of the memory. A circuit combining (comparators) is used. If necessary, an amplifier for amplifying the pulse width-modulated modulation signal output from the comparator to the driving voltage of the electron-emitting device can be added.
[0154]
In the case of a voltage modulation method using an analog signal, for example, an amplifier circuit using an operational amplifier or the like can be adopted as the modulation signal generator 1707, and a shift level circuit or the like can be added if necessary. In the case of the pulse width modulation method, for example, a voltage controlled oscillation circuit (VOC) can be adopted, and an amplifier for amplifying the voltage up to the driving voltage of the electron-emitting device can be added as necessary.
[0155]
In the image display apparatus to which the present invention can be applied, electron emission is generated by applying a voltage to each electron-emitting device via the external terminals Dox1 to Doxm and Doy1 to Doyn. A high voltage is applied to the metal back 1019 or transparent electrode (not shown) via the high voltage terminal Hv to accelerate the electron beam. The accelerated electrons collide with the fluorescent film 1018, and light is emitted to form an image.
[0156]
Next, the ladder-type arranged electron source substrate and the image display apparatus using the same will be described with reference to FIGS.
[0157]
In FIG. 14, 1011 is an electron source substrate, 1012 is an electron-emitting device, and Dx1 to Dx10 of 1126 are common wirings connected to the electron-emitting device. A plurality of electron-emitting devices 1012 are arranged in parallel in the X direction on the substrate 1011 (this is referred to as an element row). A plurality of these element rows are arranged on a substrate to form a ladder type electron source substrate. By appropriately applying a driving voltage between the common wirings of each element row, each element row can be driven independently. That is, an electron beam having a voltage equal to or higher than the electron emission threshold may be applied to an element row that emits an electron beam, and a voltage equal to or lower than an electron emission threshold may be applied to an element row that does not emit an electron beam. Further, the common wirings Dx2 to Dx9 between the element rows may be the same wiring, for example, Dx2 and Dx3.
[0158]
FIG. 15 is a diagram illustrating a structure of an image forming apparatus including an electron source having a ladder arrangement. 1120 is a grid electrode, 1121 is a hole for electrons to pass through, and 1122 is D _ox 1, D _ox 2 ... D _ox The container outer terminal 1123 is composed of G1, G2,... Gn connected to the grid electrode 1120, and 1011 is an electron source substrate in which the common wiring between the element rows is the same wiring as described above. In addition, the same code | symbol as FIG. 14, FIG. 15 shows the same member. A difference from the image forming apparatus (FIG. 1) having the simple matrix arrangement described above is that a grid electrode 1120 is provided between the electron source substrate 1011 and the face plate 1017.
[0159]
In the above-described panel structure, a spacer 120 can be provided between the face plate 1017 and the rear plate 1015 as required in terms of the atmospheric pressure structure regardless of whether the electron source arrangement is a matrix wiring or a ladder type arrangement.
[0160]
A grid electrode 1120 is provided between the substrate 1011 and the face plate 1017. The grid electrode 1120 can modulate the electron beam emitted from the surface conduction electron-emitting device 1012, and allows the electron beam to pass through a striped electrode provided perpendicular to the ladder-type device row. Therefore, one circular opening 1121 is provided corresponding to each element. The shape and installation position of the grid do not necessarily have to be as shown in FIG. 15, and there may be a large number of mesh openings as openings, and for example, it may be provided around or in the vicinity of the surface conduction electron-emitting device. Good.
[0161]
The container outer terminal 1122 and the grid container outer terminal 1123 are electrically connected to the drive circuit of FIG.
[0162]
In this image forming apparatus, each electron beam is applied by simultaneously applying a modulation signal for one image line to the grid electrode array in synchronization with the sequential driving (scanning) of each element row (one line). It is possible to control the irradiation of the phosphor and display an image line by line.
[0163]
The configurations of the two image display apparatuses described above are examples of the image forming apparatus to which the present invention can be applied, and various modifications can be made based on the idea of the present invention. Although the NTSC system is mentioned as the input signal, the input signal is not limited to this, and a TV signal (high quality TV) system including a larger number of scanning lines can be adopted besides the PAL and SECAM systems.
[0164]
Further, according to the present invention, it is possible to provide an image forming apparatus suitable not only for a television broadcast display device but also for a display device such as a video conference system or a computer. Furthermore, it can also be used as an image forming apparatus as an optical printer composed of a photosensitive drum or the like.
[0165]
【Example】
Examples will be given below to further explain the structure of the spacer, which is a feature of the present invention.
[0166]
In each of the embodiments described below, as a multi-electron beam source, N × M (M = 3072, M = 1024) surface conduction type having the electron emission portion in the conductive fine particle film between the electrodes described above. A multi-electron beam source in which a matrix wiring (see FIGS. 1 and 6) was used as the emitting element by M row-directional wirings and N column-directional wirings was used.
[0167]
[Example 1]
In this example, a display panel in which the spacer 1020 shown in FIG. Hereinafter, a detailed description will be given with reference to FIGS. 1 and 2. First, the substrate 1011 in which the row direction wiring electrode 1013, the column direction wiring electrode 1014, the inter-electrode insulating layer (not shown), and the element electrodes of the surface conduction type emission element 1012 and the conductive thin film are formed on the substrate in advance is mounted on the rear plate 1015. Next, as will be described later, among the surfaces of the insulating member 1 made of alumina and zirconia, a high resistance film 11 described later is formed on four surfaces exposed in the airtight container, and a conductive film 3 (3a) is formed on the contact surface. 3b), the spacer 1020 (height 4 mm, plate thickness 0.2 mm, length 1 mm) was fixed on the row wiring 1013 of the substrate 1011 at equal intervals in parallel with the row wiring 1013. Thereafter, a face plate 1017 having a fluorescent film 1018 and a metal back 1019 provided on the inner surface is disposed 10 mm above the substrate 1011 via a side wall 1016, and each junction of the rear plate 1015, the face plate 1017, the side wall 1016, and the spacer 1020. Fixed. The joint between the substrate 1011 and the rear plate 1015, the joint between the rear plate 1015 and the side wall 1016, and the joint between the face plate 1017 and the side wall 1016 are coated with frit glass (not shown), and 400 ° C. to 500 ° C. in the atmosphere. And sealed for 10 minutes or more.
[0168]
The spacer 1020 is a conductive material in which a conductive material such as conductive filler or metal is mixed on the row direction wiring 1013 (line width 0.3 mm) on the substrate 1011 side and on the metal back 1019 surface on the face plate 1017 side. The glass substrate was placed through a conductive frit glass (not shown), and simultaneously sealed with the above airtight container, and baked at 400 ° C. to 500 ° C. for 10 minutes or more in the atmosphere to achieve adhesion and electrical connection. In the present embodiment, as shown in FIG. 18, the fluorescent film 1018 employs a stripe shape in which each color phosphor 1301 extends in the column direction (Y direction), and the black conductor 1010 has each color phosphor (R). , G, B) Fluorescent films arranged so as to separate not only between the pixels in the Y direction but also between the pixels in the Y direction are used, and the spacers 1020 are parallel to the row direction (X direction) of the black conductor 1010. In a region (line width 300 [μm]) through a metal back 1019. Note that, when performing the above-described sealing, each color phosphor 1301 and each element disposed on the substrate 1011 must correspond to each other, so that the rear plate 1015, the face plate 1017, and the spacer 1020 are positioned sufficiently. Combined.
[0169]
The inside of the airtight container completed as described above is evacuated by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, the row direction wiring electrode is passed through the container outer terminals Dx1 to Dxm and Dy1 to Dyn. A multi-electron beam source was manufactured by supplying power to each element through 1013 and the column direction wiring electrode 1014 and performing the above-described energization forming process and energization activation process.
[0170]
Next, 10 ^-6 The exhaust pipe (not shown) was welded by heating with a gas burner at a degree of vacuum of about [Torr], and the envelope (airtight container) was sealed.
[0171]
Finally, a getter process was performed to maintain the degree of vacuum after sealing.
[0172]
In this example, the spacer substrate 1 was prepared by mixing a mixing ratio of alumina and zirconia at a weight ratio of 35:65, forming a flat plate using a doctor blade method, and then cutting with a dicing saw.
[0173]
The thermal expansion coefficient of the spacer substrate 1 is 86 × 10 6 between room temperature and 400 ° C. ^-7 The value was / ° C. The maximum temperature when assembling the spacer in the image forming apparatus was 440 ° C. In this embodiment, both the electron source substrate 1011 and the face plate substrate 1017 have a thermal expansion coefficient of 88 × 10 8 between room temperature and 400 ° C. ^-7 The spacer 1020 was connected using the above-described conductive frit on the upper and lower sides thereof using blue plate glass having a value of / ° C.
[0174]
In the present example, the high resistance film 11 was produced as follows.
[0175]
A Ti—Al alloy nitride film was formed on the spacer 112 by simultaneously sputtering a Ti and Al target with a high frequency power source. Next, the film was stabilized by being kept at 480 ° C. in the atmosphere for 6 hours. Sputtering gas is Ar: N ₂ Is a 1: 2 gas mixture and the total pressure is 1 [mTorr]. At this time, it is possible to adjust the specific resistance of the alloy nitride film by adjusting the high frequency power applied to the Ti and Al targets and the annealing conditions after film formation. In this example, the area resistance of the high resistance film is adjusted. The value is 8x10 ⁹ [Ω / □].
[0176]
In the image display apparatus using the display panel as shown in FIG. 1 and FIG. 2 completed as described above, each cold cathode element (surface conduction type emitting element) 1012 has a container external terminal Dx1 to Dxm, Dy1. Electrons are emitted by applying a scanning signal and a modulation signal through signal generation means (not shown) through ~ Dyn, and a high voltage is applied to the metal back 1019 through a high voltage terminal Hv to accelerate the emitted electron beam. An image was displayed by causing electrons to collide with the fluorescent film 1018 and exciting and emitting each color phosphor 1301 (R, G, B in FIG. 18). The applied voltage Va to the high voltage terminal Hv was 5 [kV] to 30 [kV], and the applied voltage Vf between the wirings 1013 and 1014 was 14 [V].
[0177]
At this time, two-dimensionally arranged light emitting spot arrays are formed in two dimensions including the light emitting spots due to the emitted electrons from the cold cathode element 1012 located near the spacer 1020, and a clear color image display with good color reproducibility can be achieved. Even when the spacer 1020 is provided, it is possible to obtain a high-quality image without beam deviation.
[0178]
Further, in this embodiment, it is possible to assemble a good image forming apparatus, and the high resistance film 11 is free from defects such as alkali diffusion and film peeling due to heat, and has a spacer that is stable and excellent in mass productivity. A good image forming apparatus can be obtained.
[0179]
[Example 2]
In this example, the spacer substrate was prepared by mixing a mixture ratio of alumina and zirconia at a weight ratio of 30:70, forming a flat plate using a doctor blade method, and then cutting with a dicing saw.
[0180]
The coefficient of thermal expansion is 88 × 10 8 between room temperature and 450 ° C. ^-7 The value was / ° C. The maximum temperature when assembling the spacer in the image forming apparatus was 450 ° C. In this embodiment, the electron source substrate 1011 has a thermal expansion coefficient of 88 × 10 8 at a temperature between room temperature and 400 ° C. ^-7 As the blue plate glass / face plate substrate 1017 having a value of / ° C., the thermal expansion coefficient is 84 × 10 4 at a room temperature to 400 ° C. ^-7 PD200 (manufactured by Asahi Glass) having a value of / ° C. was used, and the spacer 1020 was connected only to the electron source substrate 1011 using a conductive frit. Also, the metal plate 1010 of the face plate was not fixed with a frit or the like, but was brought into contact with a vacuum pressure to achieve electrical connection and the atmospheric pressure resistant structure was maintained with a spacer.
[0181]
This will be described with reference to FIG.
[0182]
FIG. 3 is a schematic cross-sectional view taken along the line AA ′ of FIG. 1, and the reference numerals of the respective parts correspond to those of FIGS. In this embodiment, the low resistance film 21 and the metal back 1019 are directly connected without providing the bonding material 1041 on the face plate side.
[0183]
In the present example, the high resistance film 11 was produced as follows.
[0184]
A ruthenium oxide paste made by adding a binder to a powder containing ruthenium oxide and glass as main components to form a paste is applied to the spacer substrate by a screen printing method. Thereafter, after drying at 150 ° C. for 10 minutes, the paste was similarly applied to the back surface and dried, and then baked at 850 ° C. for 30 minutes, thereby forming the high resistance film 11.
[0185]
The resistance value can be adjusted by the mixing ratio of ruthenium oxide and glass components and additives. In this embodiment, the sheet resistance value of the high resistance film 11 is 1 × 10. ⁹ [Ω / □].
[0186]
The spacer height was 2.5 mm, the spacer length was 60 mm, and the spacer thickness was approximately 0.2 mm.
[0187]
Further, as the low resistance film (intermediate electrode layer) 21, Al formed by a sputtering method was used. Furthermore, the electrical connection and mechanical fixation between the spacer 1020 and the electron source substrate wiring portion are performed by dispersing a granular glass filler whose surface is plated with Au in a paste material mainly composed of PdO, as in the first embodiment. A conductive paste (not shown) formed in this manner was formed on the wiring, and the electrical connection was measured and fixed.
[0188]
When an acceleration voltage of 6 kV was applied to the image forming apparatus of the present invention, it was possible to obtain a high-quality image without beam deviation even in the vicinity of the spacer 1020.
[0189]
Also in this embodiment, it is possible to assemble a good image forming apparatus as in the other embodiments, and the high resistance film is formed at a temperature higher than the processing temperature at the time of assembling the image forming apparatus. Therefore, no defects such as film peeling are observed with respect to the heat treatment at the time of assembling the image forming apparatus, and a stable high resistance film can be formed. In addition, since the spacer substrate 1 does not contain an alkali component, there is no diffusion of alkali elements from the spacer substrate 1 to the high resistance film 11, and the high resistance film 11 is stable without exhibiting characteristic deterioration even for long-term use. Continue to exist. As described above, it is possible to obtain a good image forming apparatus having the spacer 1020 with little characteristic deterioration.
[0190]
[Example 3]
In this embodiment, an example in which a planar field emission (FE) type electron-emitting device is used as an electron-emitting device will be described.
[0191]
FIG. 16 is a top view of a planar FE type electron emission electron source. 3101 is an electron emission portion, 3103 and 3104 are a pair of device electrodes for applying a potential to the electron emission portion 3101, and 3113 is a row wiring. Reference numeral 3114 denotes a column direction wiring, and 1020 denotes a spacer.
[0192]
In this example, the spacer substrate 1 was prepared by the following method. That is, first, a mixing ratio of alumina and zirconia is mixed as a weight ratio of 50:50, formed into a plate using a doctor blade method, fired to form a plate of 80 mm × 80 mm, and then a laser pulse is applied. Used to form a hole along the cut. Thereafter, using the same method as in Example 2, after forming the high resistance film 11, the spacer was separated by breaking the flat plate at the cut portion. Thereafter, the low resistance film 21 was formed by using the same method as in Example 1 by using the sputtering method to obtain a spacer. In this embodiment, the size of the spacer substrate 1 is 2.5 mm × 80 mm × 0.2 mm.
[0193]
The coefficient of thermal expansion is 83 × 10 5 between room temperature and 400 ° C. ^-7 The value was / ° C. The maximum temperature when assembling the spacer 1020 in the image forming apparatus was 430 ° C. In this embodiment, the electron source substrate 1011 and the face plate substrate 1017 are made of soda-lime glass, and the spacers 1020 are connected to the upper and lower portions thereof using the same conductive frit as in the first embodiment.
[0194]
By applying a voltage between the device electrodes 3103 and 3104, electrons are emitted from the sharp tip in the electron emission portion 3101, and the emitted electrons are an anode (not shown) provided to face the electron source. Is attracted to and collides with a phosphor (not shown) to cause the phosphor to emit light. In the present embodiment, spacers are formed and arranged in the same manner as in the first embodiment to form an image forming apparatus, and the same spacers as in the first embodiment are driven in the same manner. It was possible to obtain a high-quality image in which beam deviation was suppressed.
[0195]
Also in this embodiment, it is possible to assemble a good image forming apparatus as in the other embodiments, and the high resistance film 11 is formed at a temperature higher than the processing temperature at the time of assembling the image forming apparatus. Therefore, defects such as film peeling are not observed during the heat treatment at the time of assembling the image forming apparatus, and a stable high resistance film 11 can be formed. In addition, since the spacer substrate 1 does not contain an alkali component, there is no diffusion of an alkali element from the spacer substrate 1 to the high resistance film 11, and the high resistance film 11 is stable without deteriorating characteristics even for long-term use. Continue to exist. As described above, it is possible to obtain a good image forming apparatus having the spacer 1020 with little characteristic deterioration.
[0196]
[Other Examples]
In addition, the present invention can be applied to any electron-emitting device among cold-cathode electron-emitting devices other than a surface conduction electron-emitting device (SCE). As a specific example, there is a field emission type electron-emitting device in which a pair of opposed electrodes as described in Japanese Patent Laid-Open No. 63-274047 by the present applicant is configured along a substrate surface forming an electron source.
[0197]
The present invention can also be applied to an image forming apparatus using an electron source other than a simple matrix type. For example, in an image forming apparatus that performs SCE selection using a control electrode as described in JP-A-2-257551 by the applicant, the spacer of the present invention is used between the electron source and the control electrode. Can do.
[0198]
Further, according to the idea of the present invention, the image forming apparatus according to the present invention is not limited to display, but as a light emitting source that replaces a light emitting diode of an optical printer composed of a photosensitive drum and a light emitting diode, etc. The image forming apparatus of the present invention can also be used. At this time, by appropriately selecting the above-mentioned m row-directional wirings and n column-directional wirings, the present invention can be applied not only to a line-shaped light source but also to a two-dimensional light source.
[0199]
Further, according to the idea of the present invention, the present invention can also be applied to a case where a member to be irradiated with electrons emitted from an electron source is a member other than an image forming member, such as an electron microscope. Therefore, the present invention can take the form of an electron beam apparatus that does not specify the irradiated member.
[0200]
【The invention's effect】
As described above, in the image display device according to the present invention, by using the ceramic spacer substrate whose thermal expansion coefficient is almost equal to that of the electron source or the face plate substrate and whose main components are alumina and zirconia, a high temperature during the spacer manufacturing is obtained. This makes it possible to impart high stability to the high resistance film provided in the spacer. At the same time, it has been possible to prevent the defective characteristics of the high resistance film due to the diffusion of alkali elements into the high resistance film, and to supply spacers that can withstand long-term use.
[0201]
In addition, according to the present invention, it is possible to obtain a good image forming apparatus having a spacer that is excellent in mass productivity and excellent in long-term stability.
[0202]
Furthermore, the present invention does not specify the electron irradiation object, and the same effect is also obtained in an electron generator that forms a multi-plane electron source such as an apparatus for forming a latent image or an electron microscope.
[Brief description of the drawings]
FIG. 1 is a perspective view of an image display device according to an embodiment of the present invention, with a part of a display panel cut away.
FIG. 2 is a cross-sectional view taken along the line AA ′ of the display panel according to the embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along line AA ′ of a display panel according to a second embodiment of the present invention.
4A is a plan view of a planar surface conduction electron-emitting device according to an embodiment of the present invention, and FIG.
FIG. 5 is a partial cross-sectional view of a substrate of a multi-electron beam source according to an embodiment of the present invention.
FIG. 6 is a plan view of a substrate of a multi-electron beam source according to an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a vertical surface conduction electron-emitting device according to an embodiment of the present invention.
FIG. 8 is a graph showing typical characteristics of a surface conduction electron-emitting device according to an embodiment of the present invention.
9 is a cross-sectional view showing a manufacturing process of the planar surface conduction electron-emitting device of FIG.
FIG. 10 shows an applied voltage waveform during energization forming processing.
FIG. 11 shows an applied voltage waveform (a) and a change (b) in emission current Ie during energization activation processing.
12 is a cross-sectional view showing a manufacturing process of the vertical surface conduction electron-emitting device of FIG.
FIG. 13 is a block diagram showing a schematic configuration of a drive circuit of the image display device according to the embodiment of the present invention.
FIG. 14 is a schematic plan view of a ladder-type array of electron sources according to an embodiment of the present invention.
FIG. 15 is a perspective view of a flat display device having a ladder-type array of electron sources according to an embodiment of the present invention.
FIG. 16 is a view for explaining a third embodiment of the present invention, and is an explanatory view of an electron source.
FIG. 17 is a plan view illustrating the phosphor array of the face plate of the display panel.
FIG. 18 is a plan view illustrating the phosphor array of the face plate of the display panel.
FIG. 19 is a surface conduction electron-emitting device according to a conventional example.
FIG. 20 shows an FE type element according to a conventional example.
FIG. 21 shows a conventional MIM type element.
FIG. 22 is a perspective view in which a part of a display panel of an image display device according to a conventional example is cut away.
[Explanation of symbols]
1 Insulating material (spacer substrate)
11 High resistance film
3a, 3b Low resistance film (intermediate electrode layer, intermediate layer)
1011 Electron source substrate
1013 Row direction wiring
1014 Wiring in column direction
1012 Electron emitting device
1017 Face plate
1018 Fluorescent film
1019 Metal back
1041 Bonding material

Claims (11)

In an electron beam apparatus comprising an electron source, a plate facing the electron source, and a spacer disposed between the electron source and the plate,
The spacer includes a spacer substrate and a film covering at least a part of the spacer substrate,
The thermal expansion coefficient of at least one of the electron source or the plate has a value between 80 × 10 ⁻⁷ / ° C. and 90 × 10 ⁻⁷ / ° C., and the spacer substrate is made of a mixed fired product of alumina and zirconia. a ceramic, an electron beam apparatus according to claim and Turkey from 75 × 10 ^-7 / ℃ having a thermal expansion coefficient of 95 × 10 ^-7 / ℃. 2. The electron beam apparatus according to claim 1 , wherein a weight mixing ratio of the alumina and the zirconia is between 70:30 and 10:90. 3. 3. The electron beam apparatus according to claim 1, wherein the content of alkali metal in the spacer substrate is 0.1% or less. Keep electron beam apparatus according to any one of claims 1 to 3, an electron beam apparatus in which the film than the temperature at the time of the spacer assembly, is characterized in that substantially formed by previously treated with the same or higher temperature . The electron beam apparatus according to any one of claims 1 to 4, wherein the spacer has a first intermediate electrode layer, the intermediate electrode layer of the first is connected to the film and electrically, and the An electron beam apparatus, wherein the electron beam apparatus is electrically connected to a wiring portion disposed in an electron source. The electron beam apparatus according to any one of claims 1 to 5, wherein the spacer has a second intermediate electrode layer, the intermediate electrode layer of the second is connected to the film and electrically, and the An electron beam apparatus, wherein the electron beam apparatus is electrically connected to a wiring portion disposed on a plate. The electron beam apparatus according to any one of claims 1 to 6 , wherein the electron-emitting device includes a pair of opposing device electrodes and a thin film including an electron-emitting portion straddling the pair of device electrodes. An electron beam apparatus characterized by being an electron-emitting device. 8. The electron beam apparatus according to claim 7 , wherein the thin film is a film made of conductive fine particles. The electron beam apparatus according to any one of claims 1 to 8, a plurality of row wirings and column wirings for supplying a current to the electron-emitting devices on the electron source is arranged via an insulating layer The plurality of electron-emitting devices are arranged in a matrix on the electron source, and each of the plurality of electron-emitting devices is connected to each of the row-direction wirings and each of the column-direction wirings. A featured electron beam apparatus. The electron beam apparatus according to any one of claims 1 to 8, wherein the plurality of row wirings are arranged on the electron source, the plurality of electron-emitting devices arranged in a matrix on the electron source Each of the plurality of electron-emitting devices is connected to a pair of row-direction wirings among the plurality of row-direction wirings. The electron beam apparatus according to any one of claims 1 to 10, characterized in that the image forming member on which an image is formed by the collision of an electron beam accelerated by an acceleration voltage is arranged on the plate Image forming apparatus.

Images