JP4077972B2 - 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 an image display apparatus using the electron beam apparatus.
[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 element, for example, a surface conduction type emission element, a field emission type element called “FE type”, a metal / insulating layer / metal type emission element called “MIM type”, and the like are known. ing.
[0003]
As the surface conduction electron-emitting device, for example, those described in “MI Elinson, Radio Eng. Electron Phys., 10, 1290, (1965)” and other examples described later are known. .
[0004]
This surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows in parallel to a film surface of a small-area thin film formed on a substrate. As the surface conduction electron-emitting device, SnO by Erinson et al.₂In addition to those using thin films, those using Au thin films “G. Dittmer:“ Thin Solid Films ”, 9, 317 (1972)”, In₂O_Three/ SnO₂"M. Hartwell and C. G. Fonstad:" IEEE Trans. ED Conf. ", 519 (1975)", and "Three Araki et al .: Vacuum, Vol. 26, No. 1, 22 (1983)" are known. Of the image forming apparatuses using the electron-emitting devices as described above, the flat-type image forming apparatus with a small depth is attracting attention as a replacement for a cathode ray tube type display apparatus because it is space-saving and lightweight. .
[0005]
FIG. 14 is a perspective view showing an example of a display panel portion constituting a conventional flat type image forming apparatus, with a part of the display panel cut away in order to show the internal structure.
[0006]
In FIG. 14, reference numeral 2014 denotes a rear plate, reference numeral 2016 denotes a side wall, and reference numeral 2012 denotes a face plate. The rear plate 2014, the side wall 2016 and the fuse plate 2012 are used to maintain the inside of the display panel in a vacuum. (Airtight container) is formed.
[0007]
A cold cathode element 2022 is formed on the rear plate 2014, and further, row direction wiring (not shown) and column direction wiring (not shown) are wired. An insulating layer is formed between the wirings at least at a portion where the row direction wirings and the column direction wirings intersect, and electrical insulation is maintained. A portion constituted by the cold cathode elements 2022, the row direction wiring and the column direction wiring is referred to as a multi-electron beam source.
[0008]
A phosphor film (not shown) made of a phosphor is formed on the lower surface of the face plate 2012, and phosphors (not shown) of three primary colors of red (R), green (G), and blue (B) are coated. It is divided. Further, a black body (not shown) is provided between the above-described phosphors forming the fluorescent film, and a metal back (not shown) made of Al or the like is provided on the surface of the fluorescent film on the rear plate 2014 side. Is formed.
[0009]
The inside of the above airtight container is 10^-6A vacuum of about Torr is maintained, and as the display area of the image forming apparatus increases, a means for preventing deformation or destruction of the rear plate 2014 and the face plate 2012 due to a difference in atmospheric pressure between the inside and outside of the hermetic container is required. Means for preventing deformation and destruction due to a pressure difference by increasing the thickness of the rear plate 2014 and the face plate 2012 not only increases the weight of the image forming apparatus, but also causes distortion and parallax of the image when viewed from an oblique direction. Is produced. On the other hand, in the prior art shown in FIG. 14, a structural support (referred to as a spacer or a rib) 2020 made of a relatively thin glass plate for supporting atmospheric pressure is provided. In this way, the space between the rear plate 2014 on which the multi-beam electron source is formed and the face plate 2012 on which the fluorescent film is formed is usually maintained at a submillimeter to several millimeters, and the inside of the hermetic container is kept in a high vacuum as described above. Is retained.
[0010]
The image forming apparatus using the display panel described above emits electrons from each cold cathode element 2022 when a voltage is applied to each cold cathode element 2022. At the same time, a high voltage of several hundred [V] to several [kV] is applied to the metal back to accelerate the emitted electrons and collide with the inner surface of the face plate 2012. As a result, the phosphors of the respective colors forming the fluorescent film are excited to emit light, and an image is displayed.
[0011]
[Problems to be solved by the invention]
However, in the image forming apparatus described above, a high voltage of several hundred volts or more (that is, a high voltage of 1 kV / mm or more) is applied between the multi-beam electron source and the face plate in order to accelerate the emitted electrons from the cold cathode elements. Since an electric field is applied, there is a concern about creeping discharge on the spacer surface. In particular, when a part of the electrons emitted from the vicinity of the spacer hits the spacer or ions generated by the action of the emitted electrons adhere to the spacer, the spacer may be charged and discharge may be induced. is there.
[0012]
In order to solve this problem, a first means has been proposed in which charging is removed so that a minute current flows through the spacer. Specifically, by forming a high resistance film on the surface of the insulating spacer, a minute current flows on the surface of the spacer. The antistatic film used here is tin oxide, a mixed crystal thin film of tin oxide and indium oxide, or a metal film.
[0013]
Further, in order to solve the above problems, a second means for forming a stripe-shaped conductive film on the spacer in order to eliminate the influence on the potential distribution from the rear plate to the fluorescent film is the application of the present application. This is proposed in Japanese Patent Application Laid-Open No. 8-180821, filed by a person.
[0014]
On the other hand, as a means for fixing the spacer, a means for fixing using an insulating fixing member (not shown) outside the image forming area which is an electron beam emitting area is disclosed in US Pat. No. 5,731,660. Yes.
[0015]
The present applicant made an examination using both or one of the first means and the second means and the spacer fixing means, and as a result, a high voltage was applied between the rear plate and the fluorescent film. In this case, if the antistatic film or the stripe-like conductive film on the spacer exists up to the spacer fixing region (the region fixed by the fixing member), the potential distribution around the spacer fixing member becomes as shown in FIG. The problem was that electric field concentration occurred between the upper end of the substrate and the face plate, and discharge was induced by this electric field concentration. Such a discharge occurs suddenly during image formation, which not only disturbs the image but also significantly deteriorates the cold cathode device and the phosphor film in the vicinity of the discharge site.
[0016]
The present invention overcomes the conventional drawbacks due to the provision of spacers, and an electron beam that can prevent electric field concentration from occurring at the boundary between a high-resistance film or stripe-shaped conductive film and a spacer fixing member. It is an object of the present invention to provide a generator and an image forming apparatus using the electron beam generator.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, the present inventionImage formationThe device emits electronsregionTheRear plate withAnd saidWith rear plateOppositeShiThe electronicEmission areaElectrons emitted fromFace plate with electron irradiation areaAnd saidRear plateAnd saidFace plateWas installed betweenInsulativeWith support, Provided outside a space sandwiched between the electron emission region and the electron irradiation region, and having an insulating property for fixing the support to the rear plateFixed memberAnd havingOf the supportA region of the space and a region outside the space of the support;Conductive member is formedThe conductive member is not formed in a region where the support is fixed by the fixing member and a region between the fixing member and the face plate.It is characterized by that.The image forming apparatus of the present invention includes a rear plate having an electron emission region, a face plate having an electron irradiation region facing the rear plate and irradiated with electrons emitted from the electron emission region, An insulating support provided between the face plate and an insulating support for fixing the support to the face plate provided outside a space sandwiched between the electron emission region and the electron irradiation region. A conductive member is formed in a region of the space of the support and a region outside the space of the support, and the conductive member includes the fixing member. It is not formed in the area | region fixed with the said fixing member, and the area | region between this fixing member and the said rear plate, It is characterized by the above-mentioned.
[0018]
Of the present inventionImage formationAccording to the configuration of the apparatus, since the support is not fixed to the fixing member in the portion where the conductive member is formed, electric field concentration is prevented from occurring at the boundary between the conductive member and the fixing member. As a result, the discharge is prevented from being induced between the electron source or the electron irradiated member and the fixing member.
[0020]
In addition, the conductive memberIsThe electronEmission areaAnd the electronIrradiation areaElectric field betweenofdirectionWhenIt is good also as a structure provided with two or more along the perpendicular direction.
[0021]
Further, the conductive member has a sheet resistance of 10⁷-10¹⁴It is preferable that the high resistance film be Ω / □.
[0022]
Furthermore, the electrons of the supportEmission areaAnd the electronIrradiation areaAbutYouA low resistance film is formed on a portion including at least one of the surfaces on which the high resistance film is formedEmission areaAnd said electricChild irradiation areaThe high resistance film and the electrons are configured to be electrically connected to at least one of the two via the low resistance film.Emission areaOr electronicIrradiation areaAre electrically connected, and the electrons charged in the high-resistance film are electrons.Emission areaOr electronicIrradiation areaThe high resistance film becomes more difficult to be charged.
[0023]
Further, at least a part of the low resistance film may be covered with the high resistance film, and the low resistance film is covered with the high resistance film at a boundary portion with the high resistance film. A configuration is preferable. Thereby, the electric field concentration in the edge portion of the low resistance film is alleviated.
[0024]
Further, the electrons of the low resistance filmEmission areaOr the electronicIrradiation areaA portion other than the portion in contact with the high resistance film may be covered with the high resistance film, and further, the low resistance film may be configured such that all portions are covered with the high resistance film.
[0025]
The support may be constituted by forming the high resistance film after the low resistance film is formed.
[0026]
Furthermore, the outermost surface of the support has the electronsEmission areaAnd the electronIrradiation areaElectric field betweenofdirectionWhenMultiple along vertical directionStripedIt is good also as a structure provided with the electroconductive film.
[0032]
According to the image forming apparatus of the present invention configured as described above, electric field concentration is prevented from occurring at the boundary between the conductive film and the fixing member, and between the electron source or the electron irradiated member and the fixing member. As a result, it is possible to prevent a discharge from being induced, so that an image disturbance due to the discharge does not occur and a good image is formed.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0035]
First, a display panel in an embodiment of the image forming apparatus of the present invention will be described.
[0036]
FIG. 1 is a perspective view showing a display panel used in one embodiment of the image forming apparatus of the present invention, with a part cut away to show the internal structure.
[0037]
In FIG. 1, reference numeral 1015 denotes a rear plate, reference numeral 1016 denotes a side wall, and reference numeral 1017 denotes a face plate, and these form an airtight container for maintaining the inside of the display panel in a vacuum. When assembling this hermetic container, it is necessary to seal it in order to maintain sufficient strength and hermeticity at the joint of each member. Therefore, for example, frit glass is applied to the joint portion, and sealing is achieved by firing at 400 to 500 degrees Celsius for 10 minutes or more in the air or a nitrogen atmosphere. The inside of the above airtight container is 10^-6Since a vacuum of about Torr is maintained, a spacer 1020 as a support is provided in the image forming region for the purpose of preventing destruction of the airtight container due to atmospheric pressure or unexpected impact. Here, the image forming region is a region surrounded by a thick line shown in FIG. 2, and specifically, an electron emission region in the substrate 1011 as an electron source and an electron in a fluorescent film 1018 as an electron irradiation region are irradiated. It is a space that is sandwiched between areas to be created. Note that the spacer 1020 also has a function of maintaining a constant distance between the substrate 1011 serving as an electron source and the fluorescent film 1018 serving as an electron irradiation region.
[0038]
Next, the electron source substrate used in the image forming apparatus of this embodiment will be described.
The electron source substrate used in the image forming apparatus of this embodiment is configured by arranging a plurality of cold cathode elements 1012 on a substrate 1011. The cold cathode element arrangement method includes a ladder arrangement in which cold cathode elements are arranged in parallel and both ends of each element are connected by wiring, and X-directional wiring and Y-directional wiring of a pair of cold cathode element electrodes A simple matrix arrangement in which each is connected. An image forming apparatus having a ladder-type electron source substrate requires a control electrode (grid electrode) that is an electrode for controlling the flight of electrons from the electron-emitting device.
[0039]
A substrate 1011 is fixed to the rear plate 1015, and N × M cold cathode elements 1012 are formed on the substrate 1011. 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 the numbers N = 3000 and M = 1000 or more. The N × M cold cathode elements 1012 are simply matrix-wired by M row-direction wirings 1013 and N column-direction wirings 1014. A portion constituted by the substrate 1011, the cold cathode element 1012, the row direction wiring 1013, and the column direction wiring 1014 is referred to as a multi-electron beam source (electron source).
[0040]
The multi-electron beam source used in the image forming apparatus of the present embodiment is a cold cathode device as long as the cold cathode device 1012 is an electron source wired in a simple matrix or an electron source in which the cold cathode device 1012 is arranged in a ladder shape. There are no restrictions on the material, shape or manufacturing method of 1012. Therefore, for example, a surface conduction electron-emitting device, a FE type, or a MIM type cold cathode device can be used as the multi-electron beam source.
[0041]
Next, the structure of a multi-electron beam source in which surface conduction electron-emitting devices as cold cathode devices are arranged on a substrate and wired in a simple matrix will be described.
[0042]
FIG. 3 is a plan view showing a multi-electron beam source (electron source) used in the image forming apparatus shown in FIG. Surface conduction electron-emitting devices are arranged on a substrate 1011 (see FIG. 1), and these devices are wired in a simple matrix by row direction wiring electrodes 1013 and column direction wiring electrodes 1014. At portions where the row direction wiring electrodes 1013 and the column direction wiring electrodes 1014 cross each other, an insulating layer (not shown) is formed between the respective electrodes, and electrical insulation is maintained.
[0043]
The multi-electron beam 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), a device electrode of a surface conduction electron-emitting device, a conductive thin film, Is formed, and power is supplied to each element via the row direction wiring electrode 1013 and the column direction wiring electrode 1014 to perform energization forming processing and energization activation processing.
[0044]
In this 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.
[0045]
Referring to FIG. 1, a fluorescent film 1018 is formed on the lower surface of the face plate 1017. Since a color display panel is used in the image forming apparatus of this embodiment, phosphors of three primary colors red, green, and blue used in the field of CRT are separately applied to the fluorescent film 1018. For example, as shown in FIG. 4, the phosphors of the respective colors are separately applied in a stripe shape, and a black conductor 1010 is provided between the stripes of the phosphors of the respective colors. The purpose of providing the black conductor 1010 is to prevent the display color from being shifted even if there is a slight shift in the irradiation position of the electron beam, or to prevent the reflection of external light and prevent the display contrast from being lowered. This is for preventing the fluorescent film 1018 from being charged up by the electron beam. The black conductor 1010 can use graphite as a main component, but other materials may be used as long as they are suitable for the above purpose.
[0046]
Further, the method of separately applying the phosphors of the three primary colors is not limited to the stripe arrangement shown in FIG. 4, and may be, for example, a delta arrangement as shown in FIG. 5 or other arrangements. 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.
[0047]
Further, a metal back 1019 as an acceleration electrode, which is well known in the field of CRT, is provided on the surface of the fluorescent film 1018 on the rear plate 1015 side. The purpose of providing the metal back 1019 is to improve the light utilization 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 to increase the electron beam acceleration voltage. This is because it acts as an electrode for application, or acts as a conductive path for excited electrons in the fluorescent film 1018. The metal back 1019 is formed by a method of forming the 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 fluorescent film 1018, the metal back 1019 is not used.
[0048]
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.
[0049]
Next, the spacer in the image forming apparatus shown in FIG. 1 will be described in more detail.
[0050]
As shown in FIG. 1, the spacer 1020 is longer than the width of the electron beam emission region, and is fixed to the face plate 1017 or the rear plate 1015 by the fixing member 1021 outside the electron beam emission region. Usually, the fixed region of the spacer 1020 is separated from the electron emission region (image forming region) by several tens of mm or more.
[0051]
In this embodiment, the spacer 1020 is fixed by first fixing a fixing member 1021 made of an insulating material (for example, alumina) in which a groove for fixing the spacer 1020 is formed outside the image forming area on the rear plate 1015. This is performed by fixing the region using an adhesive and fixing the spacer 1020 to the groove using an adhesive. As the adhesive, an adhesive that can withstand a high temperature of several hundred degrees and has little degassing in a vacuum is desirable. For example, a ceramic adhesive is effective.
[0052]
6 is a cross-sectional view taken along line AA of the image forming apparatus shown in FIG. 1, and FIG. 7 is a front view showing the spacer and the like shown in FIG. In FIG. 6, reference numeral 1040 denotes a device electrode.
[0053]
The spacer 1020 includes a high resistance film 1020b made of a conductive film, a rear plate 1015, and a face plate 1017 for the purpose of preventing charging at least in a region excluding a fixing region of the spacer 1020 (a region fixed by the fixing member 1021). A plurality of stripe-shaped conductive films 1020d are formed to eliminate the influence on the potential distribution between the two. As described above, by forming the high resistance film 1020b and the striped conductive film 1020d on the spacer 1020 at least in the region excluding the fixed region of the spacer 1020, the high resistance film 1020b, the striped conductive film 1020d, and the spacer are formed. Electric field concentration at the boundary with the fixing member 1021 of 1020 can be prevented. The high resistance film 1020b and the stripe-shaped conductive film 1020d are formed in at least a portion of the spacer 1020 disposed in the image forming region.
[0054]
Alternatively, the high-resistance film 1020b and the stripe-shaped conductive film 1020d may be formed so as to extend to a portion disposed outside the image forming area of the spacer 1020 except for the fixed area of the spacer 1020. . As a result, the high resistance film 1020b and the stripe-shaped conductive film 1020d are provided over the entire portion of the spacer 1020 that is disposed in the image forming region, so that the spacer 1020 is more reliably prevented from being charged. The At this time, the high-resistance film 1020b and the stripe-shaped conductive film 1020d are provided in a state where a length several times the height of the spacer 1020 is extended outside the image forming region.
[0055]
Each stripe-shaped conductive film 1020d is provided along a direction perpendicular to the direction of the electric field generated between the electron source of the rear plate 1015 and the fluorescent film 1018 of the face plate 1017. Note that the spacer 1020 may have a structure in which at least one of the high resistance film 1020b and the striped conductive film 1020d is formed.
[0056]
The high resistance film 1020b is formed on at least the surface of the insulating member 1020a that is exposed to the vacuum in the airtight container. The high resistance film 1020b is formed inside the face plate 1017 (metal back 1019 and the like) and the surface of the substrate 1011 ( The row direction wiring 1013 or the column direction wiring 1014) is electrically connected. In the present embodiment, the spacer 1020 is formed in a thin plate shape, is disposed in parallel along the row direction wiring 1013, and is electrically connected to the row direction wiring 1013.
[0057]
The spacer 1020 has an insulating property 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, and the spacer 1020 It is necessary to have conductivity sufficient to prevent the surface from being charged. This point has already been described.
[0058]
Examples of the material of the insulating member 1020a of the spacer 1020 include quartz glass, glass with reduced impurity content such as Na, ceramic member such as soda lime glass, and alumina. The insulating member 1020a preferably has a coefficient of thermal expansion close to that of the members constituting the hermetic container and the substrate 1011.
[0059]
The high resistance film 1020b 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, etc.) by the resistance value Rs of the high resistance film 1020b as an antistatic film. Flows. Therefore, the resistance value Rs of the spacer is set in a desirable range from antistatic and power consumption. Surface resistance R / □ is 10 from the viewpoint of antistatic¹⁴It is preferable that it is below Ω. In order to obtain a sufficient antistatic effect, the surface resistance R / □ is 10¹³More preferably, it is Ω or less. The lower limit of the surface resistance depends on the shape of the spacer 1020 and the voltage applied between the spacers.⁷It is preferable that it is Ω or more.
[0060]
The thickness t of the high resistance film 1020b 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 having a thickness of 10 nm or less is generally formed in an island shape, and has unstable resistance and poor reproducibility. 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. Accordingly, the film thickness t is desirably 50 to 500 nm. The surface resistance R / □ is represented by ρ / t. From the above-described preferred range of the surface resistance R / □ and the thickness t of the high resistance film 1020b, the specific resistance ρ of the antistatic film is from 0.1 Ωcm to 10⁸It is preferably Ωcm. Furthermore, in order to realize a more preferable range of surface resistance and film thickness, ρ is 10²To 10⁶It is preferable to set to Ωcm.
[0061]
As described above, the temperature of the spacer 1020 rises when a current flows through the high resistance film 1020b formed thereon or when the entire display generates heat during operation. If the temperature coefficient of resistance of the high resistance film 1020b is a large negative value, the resistance value decreases when the temperature rises, the current flowing through the spacer 1020 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. Therefore, it is desirable that the resistance temperature coefficient of the high resistance film 1020b is less than −1%.
[0062]
As a material of the high resistance film 1020b having antistatic properties, for example, a metal oxide can be used. Among metal oxides, chromium, nickel, and copper oxides are preferable materials. The reason is considered that these oxides have a relatively low secondary electron emission efficiency, and are difficult to be charged even when electrons emitted from the cold cathode element 1012 hit the spacer 1020. Besides metal oxides, carbon is a preferable material because of its low secondary electron emission efficiency. In particular, since amorphous carbon has a high resistance, it is easy to control the resistance of the spacer 1020 to a desired value.
[0063]
As another material of high resistance film 1020b having antistatic properties, nitride of aluminum and transition metal alloy controls the resistance value in a wide range from a good conductor to an insulator by adjusting the composition of the transition metal. Since it can be used, it is a suitable material. Furthermore, it is a stable material with little change in resistance value in the manufacturing process of the image forming apparatus to be described later, and its temperature coefficient of resistance is less than −1%. Examples of the transition metal element include Ti, Cr, Ta and the like.
[0064]
The alloy nitride film is formed on the insulating member 1020a 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. Since the film forming range is only a portion exposed in the image forming region, the region for fixing the spacer 1020 to the face plate 1017 or the rear plate 1015 is subjected to mask processing or the like. In addition, a film forming method such as dipping can be used by using the region where no film is formed.
[0065]
Referring to FIG. 1 again, 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.
[0066]
Further, in order to evacuate the inside of the hermetic container to a vacuum, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is^-7Exhaust to a vacuum level of about 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 10 by the adsorption action of the getter film.^-FiveTo 10^-7The Torr vacuum is maintained.
[0067]
The image forming apparatus using the display panel described above emits electrons from each cold cathode element 1012 when a voltage is applied to each cold cathode element 1012 through the container 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 the fluorescent film 1018 as a target on the inner surface of the face plate 1017. Collide with. Thereby, the phosphors of the respective colors forming the fluorescent film 1018 are excited to emit light, and an image is displayed.
[0068]
Usually, the voltage applied to the surface conduction electron-emitting device (cold cathode device 1012) is about 12 to 16 [V], and the distance between the metal back 1019 and the cold cathode device 1012 is about 0.1 to 8 [mm]. The voltage between 1019 and the cold cathode element 1012 is about 0.1 to 10 [kV].
[0069]
The basic configuration and manufacturing method of the display panel in the image forming apparatus of the present embodiment and the outline of the image forming apparatus have been described above.
[0070]
Note that the present invention is not limited to an image forming apparatus suitable for image display, and is described above as a light-emitting source that replaces a light-emitting diode or the like in an optical printer that includes, for example, a photosensitive drum and a light-emitting diode. Such an image forming apparatus can also be used. The image forming member is not limited to a material that directly emits light, such as a phosphor, and may be a member that forms a latent image by charging with electrons. Furthermore, the present invention can also 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 generator that does not specify the electron irradiated member.
[0071]
【Example】
Next, a specific configuration of the image forming apparatus described above will be described with reference to the drawings.
[0072]
(First embodiment)
FIG. 8 is a sectional view showing a first embodiment of the image forming apparatus of the present invention. In FIG. 8, reference numeral 1015 denotes a rear plate, reference numeral 1016 denotes a side wall, and reference numeral 1017 denotes a face plate. The rear plate 1015, the side wall 1016, and the fuse plate 1017 are used to maintain the inside of the display panel in a vacuum. An envelope (airtight container) is formed.
[0073]
A cold cathode element 1021 (see FIG. 1) is formed on the substrate 1011 fixed on the rear plate 1015, and row-direction wirings 1013 and column-direction wirings 1014 (see FIG. 1) are wired. At least a portion where the row direction wiring 1013 and the column direction wiring 1014 intersect each other, an insulating layer (not shown) is formed between the both wirings, and electrical insulation is maintained.
[0074]
A phosphor film 1018 made of a phosphor is formed on the lower surface of the face plate 1017, and phosphors of three primary colors (not shown) of red (R), green (G), and blue (B) are separately applied. Yes. Also, a black body (not shown) is provided between the color phosphors forming the fluorescent film 1018, and a metal back 1019 made of Al or the like is formed on the surface of the fluorescent film 1018 on the rear plate 1015 side. ing.
[0075]
Further, a support body (referred to as a spacer or a rib) 1120 made of a relatively thin glass plate and supporting atmospheric pressure is provided inside the image forming apparatus using an insulating jig (not shown) on the substrate 1011. Is provided.
[0076]
As shown in FIGS. 8 and 9, the spacer 1120 of this embodiment has at least a surface in contact with the rear plate 1015 or the fluorescent film 1018 in order to make the high resistance film 1120 b as an antistatic film function reliably. A low resistance film 1120c is provided on one surface. Thereby, the electrical connection between the high resistance film 1120b and the rear plate 1015 or the fluorescent film 1018 is ensured. In addition, by adopting a configuration in which at least a part of the low resistance film 1120c is covered with the high resistance film 1120b, electric field concentration at the edge portion of the low resistance film 1120c is reduced.
[0077]
Here, the low resistance film 1120c means that carriers (electrons or holes) are substantially transferred from the high resistance film 1120b to the electron source side or the positive control electrode (acceleration electrode) side as compared with the case where the low resistance film is not provided. That can be moved easily. More specifically, the relationship between the high resistance film and the low resistance film is such that the resistivity of the high resistance film is higher than the resistivity of the low resistance film, or the sheet resistance of the high resistance film is low. It is only necessary to satisfy at least one of the conditions that the sheet resistance of the film is higher and the carrier of the high resistance film can be easily moved to the electron source side or the control electrode side. Hereinafter, the name of the intermediate electrode layer (intermediate layer) is also used for the low resistance film. The intermediate electrode layer (intermediate layer) has a plurality of functions listed in the following (1) to (3).
[0078]
(1) The high resistance film 1120b is electrically connected to the face plate 1017 and the substrate 1011.
[0079]
As described above, the high-resistance film 1120b is provided for the purpose of preventing charging on the surface of the spacer 1120. However, the high-resistance film 1120b is formed by using the face plate 1017 (metal back 1019 and the like) and the substrate 1011 (wiring). 1013, 1014, etc.), a large contact resistance is generated at the interface of the connection portion, and there is a possibility that charges generated on the surface of the spacer 1120 cannot be quickly removed. In order to avoid this, a low-resistance intermediate layer is provided on the contact surface or side surface of the spacer 1120 that contacts the face plate 1017 and the substrate 1011.
[0080]
(2) The potential distribution of the high resistance film 1120b is made uniform.
[0081]
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 1120, it is necessary to control the potential distribution of the high resistance film 1120b over the entire region. When the high resistance film 1120b is directly connected to the face plate 1017 (metal back 1019, etc.) and the substrate 1011 (wirings 1013, 1014, etc.), unevenness of the connection state occurs due to the contact resistance at the interface of the connection portion. There is a possibility that the potential distribution of 1120b 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 end portion (contact surface or side surface portion) of the spacer 1120 where the spacer 1120 contacts the face plate 1017 and the substrate 1011. By applying a potential, the potential of the entire high resistance film 1120b can be controlled.
[0082]
(3) Control the orbit of emitted electrons.
[0083]
As described above, the electrons emitted from the cold cathode element 1012 form an electron trajectory according to the potential distribution formed between the face plate 1017 and the substrate 1011. With respect to the trajectory of electrons emitted from the cold cathode element 1012 in the vicinity of the spacer 1120, restrictions (wiring, change in element position, etc.) associated with the installation of the spacer 1120 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 of the face plate 1017 and the substrate 1011 that comes into contact with the substrate, the potential distribution in the vicinity of the spacer 1120 can have desired characteristics and the trajectory of emitted electrons can be controlled. .
[0084]
The material of the low resistance film 1120c may be selected from those having a sufficiently low resistance value compared to the material of the high resistance film 1120b. Ni, Cr, Au, Mo, W, Py, Ti, Al, Cu , Pd and other metals or alloys, and Pd, Ag, Au, RuO₂, Pd-Ag or other metal or metal oxide and printed conductor made of glass, or In₂O_Three-SnO₂It can be selected as appropriate from transparent conductors such as, and semiconductor materials such as polysilicon.
[0085]
Further, in order to eliminate the influence on the potential distribution from the rear plate 1015 to the fluorescent film 1018, a striped conductive film 1120d was formed on the spacer 1120. As described above, the high resistance film 1120b, the low resistance film 1120c, and the striped conductive film 1120d are formed on the spacer 1120 in at least the region excluding the fixed region of the spacer 1120, whereby the high resistance film 1120b and the low resistance film are formed. 1120c and stripe-shaped conductive film 1120d prevent the electric field from being expanded, the influence on the emitted electron trajectory is eliminated, and high-resistance film 1120b, low-resistance film 1120c, stripe-shaped conductive film 1120d and fixing member 1021 for spacer 1120 Electric field concentration at the boundary of the
[0086]
FIG. 9 is a front view showing the spacer and the like shown in FIG. Cold cathode elements 1012 are arranged on the substrate 1011, and an electron emission region L is formed. The spacer 1120 is fixed by a fixing member 1021 at a distance of L2 from the electron emission region. Here, the length of L2 is about 20 mm. On the spacer 1120, a conductive film is formed from the electron emission region to L1. Here, the length of L1 was 6 mm. The height of the spacer 1120 was 2 mm.
[0087]
Thus, the gap between the rear plate 1015 on which the multi-beam electron source is formed as described above and the face plate 1017 on which the fluorescent film 1018 is formed is maintained at a distance of about 2 mm. High vacuum is maintained.
[0088]
(Second embodiment)
FIG. 10 is a cross-sectional view showing a second embodiment of the image forming apparatus of the present invention, and FIG. 11 is a front view showing the spacer and the like shown in FIG. 10, the same components as those in the image forming apparatus shown in FIG. 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0089]
The spacer 1220 in this embodiment is configured in the same manner as the spacer 1120 shown in FIGS. 8 and 9 except that the stripe-shaped conductive film is not provided on the side surface. Also in this example, electric field concentration at the boundary between the high resistance film 1220b and the low resistance film 1220c and the fixing member 1021 of the spacer 1220 could be prevented.
[0090]
(Third embodiment)
FIG. 12 is a sectional view showing a third embodiment of the image forming apparatus of the present invention, and FIG. 13 is a front view showing the spacer and the like shown in FIG. 12, the same components as those in the image forming apparatus shown in FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0091]
The spacer 1320 in this embodiment is configured in the same manner as the spacer 1120 shown in FIGS. 8 and 9 except that the high resistance film and the low resistance film are not provided. Also in this example, electric field concentration at the boundary between the stripe-shaped conductive film 1320d and the fixing member 1021 of the spacer 1320 could be prevented.
[0092]
In the above embodiment and each example, the case where the spacer fixing member is fixed to the rear plate 1015 is described as an example. However, even when the spacer fixing member is fixed to the face plate 1017 side, The same effect can be obtained.
[0093]
【The invention's effect】
As described above, according to the present invention, the support is placed outside the predetermined region sandwiched between the region where electrons are emitted from the electron source and the region where electrons are irradiated on the electron irradiated member. Since a fixing member for fixing to the irradiation member is provided, and a conductive member for preventing the support from being charged is formed in a portion arranged in at least a predetermined region of the support, It is possible to prevent electric field concentration from occurring at the boundary between the conductive member and the fixing member, and consequently to prevent discharge from being induced between the electron source or the electron irradiated member and the fixing member.
[Brief description of the drawings]
FIG. 1 is a perspective view of a display panel used in an embodiment of an image forming apparatus of the present invention, with a part cut away to show the internal structure.
FIG. 2 is a perspective view showing an image forming area in the image forming apparatus shown in FIG.
3 is a plan view showing a multi-electron beam source (electron source) used in the image forming apparatus shown in FIG.
4 is a diagram illustrating a state in which phosphors are separately applied to the phosphor film of the image forming apparatus illustrated in FIG. 1. FIG.
FIG. 5 is a diagram showing another state where the phosphor in the phosphor film of the image forming apparatus shown in FIG. 1 is separately applied.
6 is a cross-sectional view taken along line AA of the image forming apparatus shown in FIG.
7 is a front view showing the spacer and the like shown in FIG. 6. FIG.
FIG. 8 is a cross-sectional view showing a first embodiment of the image forming apparatus of the present invention.
9 is a front view showing the spacer and the like shown in FIG.
FIG. 10 is a cross-sectional view showing a second embodiment of the image forming apparatus of the present invention.
11 is a front view showing the spacer and the like shown in FIG.
FIG. 12 is a cross-sectional view showing a third embodiment of the image forming apparatus of the present invention.
13 is a front view showing the spacer and the like shown in FIG.
FIG. 14 is a perspective view showing an example of a display panel portion forming a conventional flat type image forming apparatus, with a part of the display panel cut away in order to show the internal structure.
FIG. 15 is a diagram illustrating a potential distribution around a spacer fixing member in a conventional image forming apparatus.
[Explanation of symbols]
1010 Black conductive material
1011 substrate
1012 Cold cathode device
1013 Row direction wiring electrode
1014 Column direction wiring electrode
1015 Rear plate
1016 side wall
1017 Face plate
1018 Fluorescent film
1019 Metal back
1020, 1120, 1220, 1320 Spacer
1020a, 1120a, 1220a, 1320a Insulating member
1020b, 1120b, 1220b High resistance film
1020d, 1120d, 1320d Striped conductive film
1021 Fixing member
1120c, 1220c Low resistance film

Claims (11)

A rear plate with an electron emission region;
A face plate having an electron irradiation region facing the rear plate and irradiated with electrons emitted from the electron emission region;
An insulating support installed between the rear plate and the face plate;
Provided outside the space sandwiched between the electron emission region and the electron irradiation region, an insulating fixing member for fixing the support to the Riapure bets,
Have
Wherein a region of the space of the support, and the outer region of the front Symbol space of the support, and the conductive member is formed on,
The conductive member is not formed in a region where the support is fixed by the fixing member and a region between the fixing member and the face plate.
An image forming apparatus. A rear plate with an electron emission region;
A face plate provided with an electron irradiation region facing the rear plate and irradiated with electrons emitted from the electron emission region;
An insulating support disposed between the face plate;
An insulating fixing member that is provided outside a space sandwiched between the electron emission region and the electron irradiation region, and fixes the support to the face plate;
Have
Conductive members are formed in the region of the space of the support and the region outside the space of the support,
The conductive member is not formed in a region where the support is fixed by the fixing member and a region between the fixing member and the rear plate.
An image forming apparatus. The conductive member along the electric field direction perpendicular to the direction between the electron emission region and the electron irradiation region provided with a plurality, the image forming apparatus according to claim 1 or 2. 4. The image forming apparatus according to claim 1, wherein the conductive member is a high resistance film having a sheet resistance of 10 ⁷ to 10 ¹⁴ Ω / □. 5. A low resistance film is formed on a portion including at least one surface of the support in contact with the electron emission region and the electron irradiation region, and the high resistance film is formed between the electron emission region and the electron irradiation region. The image forming apparatus according to claim 4 , wherein the image forming apparatus is electrically connected to at least one of the low resistance films. The image forming apparatus according to claim 5 , wherein at least a part of the low resistance film is covered with the high resistance film. The image forming apparatus according to claim 6 , wherein a boundary portion between the low resistance film and the high resistance film is covered with the high resistance film. 8. The image forming apparatus according to claim 7 , wherein a portion of the low-resistance film excluding a portion in contact with the electron emission region or the electron irradiation region is covered with the high-resistance film. The image forming apparatus according to claim 8 , wherein the low resistance film is entirely covered with the high resistance film. The support is the low resistance film is constructed by the high resistance film is formed after the formed image forming apparatus according to any one of claims 5 9. Wherein the outermost surface of the support has a plurality of stripe-shaped conductive film is provided along a direction perpendicular to the direction of the electric field between the electron-irradiated region and the electron-emitting region, 10 from claim 5 The image forming apparatus according to any one of the above.

Images