JP2008071661A - Image display device - Google Patents

Abstract

In a flat-type image display device, an electron source, signal wiring, and the like are protected from creeping discharge along the surface of a frame.
A rear substrate provided with a plurality of signal wirings and 9 and an electron source on a glass substrate, a front substrate (not shown) disposed opposite to the rear substrate, and between the rear substrate and the front substrate. A flat image display device provided with a frame body 3 interposed between the insulating layer 141 and the inside of the frame body 3 so as to cover a part of the signal wirings 8 and 9; A protective electrode 14 held at the ground potential was disposed.
[Selection] Figure 2

Description

  The present invention relates to a self-luminous flat panel image display device, and more particularly to an image display device in which electron sources are arranged in a matrix.

  As one of self-luminous flat panel displays (FPDs) having electron sources arranged in a matrix, a field emission image display (FED: Field Emission Display) using a small and stackable cold cathode or an electron emission type An image display device is known. These cold cathodes include spindt type electron sources, surface conduction type electron sources, carbon nanotube type electron sources, metal-insulator-metal (MIM) type metal-insulator-metal, and metal-insulator-semiconductors. There are stacked MIS (Metal-Insulator-Semiconductor) type or metal-insulator-semiconductor-metal type electron sources.

  A general self-luminous FPD includes a rear panel having the electron source as described above on a rear substrate made of a glass plate, a phosphor layer, and electrons emitted from the electron source to the phosphor layer. A front panel having an anode for forming an electric field on the front substrate made of a glass plate, and a frame body that holds internal spaces facing each other at a predetermined interval. The display space to be formed is configured to be kept in a vacuum state, and the display panel is configured by combining a drive circuit.

  The back panel of the back panel has a plurality of scanning signal wirings extending in one direction and arranged in parallel in another direction orthogonal to the one direction and sequentially applying a scanning signal in the other direction. Furthermore, a plurality of image signal wirings arranged in the one direction so as to extend in the other direction and intersect the scanning signal wirings are provided on the rear substrate. In addition, the electron source is provided near each intersection of the scanning signal wiring and the image signal wiring. The scanning signal wiring and the electron source are connected by a feeding electrode, and current is supplied from the scanning signal wiring to the electron source. The configuration is general.

  Further, the individual electron sources are paired with a corresponding phosphor layer to constitute a unit pixel. Usually, one pixel (color pixel, pixel) is composed of unit pixels of three colors of red (R), green (G), and blue (B). In the case of a color pixel, the unit pixel is also called a sub-pixel (sub-pixel).

  In addition to the above-described configuration, in the image display device as described above, a plurality of spacing members (spacers) are arranged and fixed in a display area surrounded by the frame body between the rear panel and the front panel, Is maintained at a predetermined interval in cooperation with the frame. This spacer is generally composed of a plate-like body formed of an insulating material such as glass or ceramics or a member having some conductivity, and is usually installed at a position where the operation of the pixel is not hindered for each of a plurality of pixels. .

The frame body serving as a sealing frame is fixed to the inner peripheral edge of the back substrate and the front substrate with a sealing member such as frit glass, and the fixing portion is hermetically sealed to form a sealing region. The degree of vacuum inside the display area formed by both substrates and the frame is, for example, about 10 ⁻⁵ to 10 ⁻⁷ Torr.

A scanning signal wiring lead terminal connected to the scanning signal wiring formed on the rear substrate and an image signal wiring lead terminal connected to the image signal wiring pass through the sealing region between the frame and both substrates.
JP 2002-75254 A JP 2002-100313 A JP 2004-363075 A

  With respect to the self-luminous image display device as described above, Patent Document 1 has a configuration in which electrodes are provided on the contact surfaces of the frame body with both substrates and a high resistance film is disposed on the side wall side surface in contact with the contact surfaces. It is disclosed. Patent Document 2 discloses a configuration in which two types of resistance films having different resistance values are sequentially arranged outside the display area in order to prevent discharge.

  In this type of image display apparatus, the countermeasure against discharge is indispensable. However, there has been a risk of causing contamination and damage to the inner surfaces of both substrates including the display area as a countermeasure against this, and this causes deterioration of display quality and a problem that hinders long life. Contains.

  It is an object of the present invention to provide a long-life image display device that solves the above-described problems and has excellent display quality.

In order to achieve the above object, the present invention is arranged through an insulating layer that is close to the inside of the frame and provided on the back substrate and covers a part of the image signal wiring, and is held at a potential lower than the acceleration electrode potential. The protective electrode is provided.
The present invention is further characterized by further comprising a high-resistance film that covers the end of the fluorescent film and extends in the direction of the frame and is disposed at a predetermined distance from the frame.
Furthermore, the present invention is characterized in that in addition to the high resistance film connected to the fluorescent film, a second high resistance film is disposed on the inner surface of the frame.

A protective electrode is disposed through an insulating layer that covers a part of the image signal wiring in the vicinity of the inside of the frame, and this protective electrode is held at a potential lower than the acceleration electrode potential. The signal wiring on the rear substrate can be protected from surface creeping discharge, and a long-life image display device with excellent display quality has been made possible.
In addition, a high-resistance film is further arranged to cover the end of the fluorescent film, so that this high-resistance film becomes a high-voltage potential relaxation layer, and the electric field concentration at the end face of the high-voltage application portion of the fluorescent screen is alleviated, thereby suppressing discharge. In combination with the effect of the protective electrode, a long-life image display device with excellent display quality was made possible.
Furthermore, by disposing the second high resistance film on the inner side surface of the frame, it is possible to further suppress the occurrence of discharge and to enable a long-life image display device with excellent display quality.

  Hereinafter, the present invention will be described in detail with reference to the drawings of the embodiments.

  1 to 4 are schematic views for explaining a first embodiment of an image display device according to the present invention. FIG. 1A is a plan view seen from the front substrate side, and FIG. FIG. 2 is a plan view taken along line AA in FIG. 1B, FIG. 3 is a sectional view taken along line BB in FIG. 1, and FIG. 4 is CC in FIG. It is sectional drawing along a line.

  1 to 4, reference numeral 1 is a rear substrate, 2 is a front substrate, 3 is a frame, 4 is an exhaust pipe, 5 is a sealing member, 6 is a display area, 7 is a through hole, and 8 is a video signal. Wiring, 9 scanning signal wiring, 10 electron source, 11 connection wiring, 12 spacer, 13 adhesive member, 14 protective electrode, 15 phosphor layer, 16 BM (black matrix) film for light shielding, 17 is a metal back (acceleration electrode) made of a metal thin film, and 18 is a high resistance film.

  Both the substrates 1 and 2 are made of glass plates having a thickness of several millimeters, for example, about 1 to 10 mm, and both the substrates have a substantially rectangular shape and are laminated at a predetermined interval. Reference numeral 3 denotes a frame body having a frame shape. The frame body 3 is made of, for example, a sintered body of frit glass or a glass plate, and has a substantially rectangular shape by itself or a combination of a plurality of members. Between the two.

  The frame 3 is inserted in a peripheral portion between the substrates 1 and 2, and both end surfaces are hermetically bonded to the substrates 1 and 2. The thickness of the frame 3 is set to several mm to several tens mm, and the height thereof is set to a dimension substantially equal to the distance between the substrates 1 and 2. Reference numeral 4 is an exhaust pipe, and the exhaust pipe 4 is fixed to the back substrate 1. Reference numeral 5 denotes a sealing member. The sealing member 5 is made of, for example, frit glass. The frame 3 and the substrates 1 and 2 are joined and hermetically sealed.

A space including the frame 3 and the display region 6 surrounded by the substrates 1 and 2 and the sealing member 5 is evacuated through the exhaust pipe 4 and maintains a vacuum degree of 10 ⁻⁵ to 10 ⁻⁷ Torr, for example. ing. The exhaust pipe 4 is attached to the outer surface of the rear substrate 1 as described above, and communicates with a through hole 7 formed through the rear substrate 1 so that the exhaust pipe 4 is exhausted after exhausting is completed. Is sealed.

  Reference numeral 8 denotes a video signal wiring. The video signal wiring 8 is made of a metal material as will be described later, and extends in one direction (Y direction) on the inner surface of the rear substrate 1 and is arranged in parallel in the other direction (X direction). Has been. The video signal wiring 8 airtightly penetrates the sealing region between the frame 3 and the rear substrate 1 from the space including the display region 6 and extends to the end surface of the rear substrate 1. The video signal wiring 8 has a video signal wiring lead-out terminal 81 at the tip outside the sealing area.

  Reference numeral 9 denotes a scanning signal wiring. The scanning signal wiring 9 is made of a metal material as will be described later, and extends on the video signal wiring 8 in the other direction (X direction) intersecting with the one direction (X direction). (Y direction). The scanning signal wiring 9 airtightly penetrates the sealing region between the frame 3 and the back substrate 1 from the space including the display region 6 and extends to the vicinity of the end surface of the back substrate 1. The scanning signal wiring 9 has a distal end portion outside the sealing region as a scanning signal wiring lead terminal 91.

  Reference numeral 10 is, for example, a kind of MIM type electron source disclosed in Patent Document 3, and this electron source 10 is provided in the vicinity of each intersection of the scanning signal wiring 9 and the video signal wiring 8. The electron source 10 is connected to the scanning signal wiring 9 through a connection line 11. An interlayer insulating film INS is disposed between the video signal wiring 8 and the upper electrode of the electron source 10 and the scanning signal wiring 9.

  Here, the video signal wiring 8 is made of, for example, an Al (aluminum) film, and the scanning signal wiring 9 is made of, for example, a Cr / Al / Cr film or a Cr / Cu / Cr film. The wiring lead terminals 81 and 91 are provided at both ends of the signal wiring, respectively, but may be provided only at one end.

Next, reference numeral 12 denotes a spacer, and the spacer 12 is formed of a plate-like body formed of an insulating material such as glass or ceramics or a member having some conductivity. Installed in a position that does not interfere with operation. The spacer 12 has a specific resistance of about 10 ⁸ to 10 ⁹ Ω · cm, and has a configuration in which the resistance value is unevenly distributed as a whole. Then, every other spacer 12 is arranged upright on the scanning signal wiring 9 substantially parallel to the frame 3, and is bonded and fixed to both the substrates 1 and 2 by an adhesive member 13. Further, the spacer 12 may be fixed to the substrate only on one end side, and the arrangement is usually set at a position where the operation of the pixel is not hindered for each of the plurality of pixels. Furthermore, it is possible to arrange every several lines on the scanning signal wiring 9.

  The dimensions of the spacer 12 are set according to the substrate dimensions, the height of the frame 3, the substrate material, the spacer spacing, the spacer material, etc. Generally, the height is substantially the same as the frame 3 described above, The thickness is several tens μm to several mm or less. The length of the spacer can be about 20 mm to 1000 mm, and even longer. A practical value is preferably about 80 mm to 300 mm.

  Reference numeral 14 is a protective electrode, and the protective electrode 14 is made of a silver (Ag) material. The protective electrode 14 is close to the inside of the frame 3 over the entire circumference, and the both electrodes are interposed via an insulating layer 141 made of a glass plate. The signal wirings 8 and 9 are arranged so as to cover a part. The glass plate constituting the insulating layer 141 has a plate thickness of 0.3 mm and a width of 3 mm, and the protective electrode 14 has a thickness of 20 μm.

The protective electrode 14 is connected to a power supply terminal 142 disposed at each corner, and is connected to one end of the protective electrode wiring 143 via the power supply terminal 142 and is held at a predetermined potential, for example, a ground potential. The power supply terminal 142 has a role of fixing the protective electrode 14 together with the electrical connection described above.
On the other hand, the other end side of the protective electrode wiring 143 hermetically penetrates the sealing region between the frame 3 and the rear substrate 1 and is provided in the gap between the signal wiring leading terminals 81 and 91. 144 is connected.

  The protective electrode 14 can be made of a metal material that emits less gas, such as gold (Au) or nickel (Ni), in addition to the above-described Ag, and the insulating layer 141 can be made of the glass plate described above. For example, an insulating material such as a ceramic plate or frit glass such as the sealing member 5 can be used.

  The power supply terminal 142 is made of a metal material (42% Ni, 6% Cr, 52% Fe) having a thermal expansion coefficient close to that of glass in the first embodiment, and the power supply terminal 142 is fixed to the rear substrate 1. Used.

  On the other hand, on the inner surface of the front substrate 2 to which one end side of the spacer 12 is fixed, a phosphor layer 15 for red, green, and blue is disposed in a window section partitioned by a light-shielding BM (black matrix) film 16. A metal back (acceleration electrode) 17 made of a metal thin film is provided by, for example, a vapor deposition method so as to cover these to form a phosphor screen. During operation, an anode voltage of about 3 kv to 20 kv is applied to this phosphor screen. The metal back 17 is a light reflecting film for reflecting the light emitted to the side opposite to the front substrate 2, that is, the back substrate 1 toward the front substrate 2, and increasing the light emission efficiency, and charging the surface of the phosphor particles. Also has a function to prevent.

Examples of the phosphor include Y ₂ O ₃ : Eu and Y ₂ O ₂ S: Eu for red, ZnS: Cu, Al, Y ₂ SiO ₅ : Tb for green, and ZnS for blue. : Ag, Cl, ZnS: Ag, Al, etc. can be used. The phosphor layer 15 has an average particle diameter of phosphor particles of, for example, 4 μm to 9 μm, and a film thickness of, for example, about 10 μm to 20 μm.

Next, FIG. 5 is a schematic cross-sectional view corresponding to FIG. 4 for explaining the second embodiment of the image display device according to the present invention. In FIG.
In FIG. 5, the protective electrode 14 is disposed on the insulating layer 141 and is electrically connected to the protective electrode wiring 143 through the metal layer 146 of the through hole 145 that penetrates the insulating layer 141.
The insulating layer 141 covers a signal wiring (not shown) and is fixed to the back substrate 1 through a fixing material 147 such as frit glass.

  In the configuration of the second embodiment, since the insulating layer 141 is fixed to the back substrate 1 via the fixing material 147, the above-described feeding terminal 142 is not required, and the number of parts and the number of man-hours can be reduced. .

Next, FIG. 6 is a schematic cross-sectional view for explaining a third embodiment of the image display device according to the present invention. In FIG.
In FIG. 6, the configuration on the back substrate 1 side is the same as that of the above-described second embodiment, and a high resistance film 18 is arranged on the phosphor screen side of the front substrate 2.
The high-resistance film indicated by reference numeral 18 covers the entire periphery of the end 171 of the metal back 17 and extends in the direction of the frame 3, and the end 181 is not spaced apart from the frame 3 by a certain distance S 1. Arranged as a contact. On the other hand, the start end 182 of the high-resistance film 18 is disposed so as to overlap and cover the entire circumference of the end 171 of the metal back 17 as described above, and functions as a high-voltage potential relaxation layer.

  The high / low resistance film 18 covers the end 171 of the metal back 17 and extends in the direction of the frame 3, but has a length from the end 171 of the metal back 17 to the end 181 of the high resistance film 18. L1 needs to be about 3 mm to 10 mm. If this length is less than 3 mm, the high-voltage potential relaxation effect cannot be expected, and if it exceeds 10 mm, the display area becomes narrow and the peripheral area becomes wide. Preferably, it is about 4 mm to 8 mm. Further, the film thickness is required to be 3 μm to 20 μm, and particularly preferably 5 μm to 10 μm. If this is less than 3 μm, the film may disappear, and if it exceeds 20 μm, the high-voltage potential relaxation effect cannot be expected.

The high and low resistance film 18 is made of an insulating high resistance oxide such as iron oxide or chromium oxide and an inorganic binder such as water glass. For example, Fe ₂ O _{3 which} has been used in cathode ray tubes or the like is recommended as iron oxide, and Cr ₂ O ₃ is recommended as chromium oxide. In this configuration, the iron oxide, chromium oxide or the like having a particle size of 0.1 μm to 10 μm is used. In particular, if it exceeds 10 μm, there is a problem that the potential relaxation effect is small, and it is preferably about 0.5 μm to 3 μm.

In the case of using water glass that has been used in cathode ray tubes or the like as the inorganic binder of the high and low resistance film 18, the water glass is 1 to 20% by weight, preferably about 3 to 10% by weight. Further, in the combination of water glass and Fe ₂ O ₃ or the combination of water glass and Cr ₂ O ₃ , the mixing ratio is 1: 4 to 1:10 for water glass: Fe ₂ O ₃ , and water glass: Cr ₂ O _3. Is preferably 1: 4 to 1:10.

The formation of the high and low anti-film 18 is completed by applying a mixed solution of the above materials to the site using a known jig such as a sponge, a brush, or a brush, and drying. The resistance value after completion is 10 ⁹ Ω / □ to 10 ¹³ Ω / □, which is a highly different high resistance film compared to about 10 ² Ω / □ or less of the resistance of the phosphor screen on which the metal back 17 is formed. Yes.

  In the third embodiment, the high voltage resistance is reduced by the arrangement of the high and low resistance film 18, and the electric field in the vicinity of the end 171 of the metal back 17 is smoothed. As a result, the number of occurrences of discharge is drastically reduced. As a result, a long-life image display device with excellent display quality could be obtained.

  FIG. 7 is a schematic cross-sectional view showing a fourth embodiment of the image display device of the present invention, which corresponds to FIG. 6, and the same parts as those shown in FIG.

  In FIG. 7, reference numeral 28 is a high-resistance film, and this high-resistance film 28 is disposed on the inner surface 31 of the frame 3 in a non-contact state with the inner surface 31 thereof. The high resistance film 28 is formed of the same composition as the high resistance film 18 disposed on the phosphor screen side. The film thickness is also set within the same dimensions as in Example 3.

  In Example 4, in addition to the high and low resistance film 18 disposed on the phosphor screen side, the second high resistance film 28 is disposed on the inner surface 31 over the entire circumference of the frame 3, thereby reducing the high voltage potential. As a result, the inclination of the equipotential line near the terminal end 171 of the metal back 17 is further smoothed. As a result, the number of occurrences of discharge is drastically reduced, coupled with the effect of the protective electrode 14, and a long-life image display with excellent display quality. Could get the device.

  In each of the above-described embodiments, the structure using the MIM as the electron source is taken as an example. However, the present invention is not limited to this, and the self-luminous FPD using the various electron sources described above is also applicable. The same applies.

FIG. 1A is a schematic diagram for explaining a first embodiment of an image display device according to the present invention, FIG. 1A is a plan view seen from the front substrate side, and FIG. 1B is a side view of FIG. . It is a schematic plan view along the AA line of FIG.1 (b). It is a schematic cross section along the BB line of Drawing 1 (a). It is a schematic cross section along the CC line of FIG. It is a schematic cross section corresponding to FIG. 4 explaining the 2nd Example of the image display apparatus by this invention. It is a schematic cross section explaining the 3rd example of the image display device by the present invention. It is a schematic cross section corresponding to FIG. 6 explaining the 4th Example of the image display apparatus by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Back substrate, 2 ... Front substrate, 3 ... Frame body, 4 ... Exhaust pipe, 5 ... Sealing member, 6 ... Display area, 7 ... Through-hole, 8 ... Image signal wiring, 81 ... Image signal wiring lead terminal, 9 ... Scanning signal wiring, 91 ... Scanning signal wiring lead terminal, 10 ... Electron source, 11 ... Connection wiring, DESCRIPTION OF SYMBOLS 12 ... Spacer, 13 ... Adhesive member, 14 ... Protection electrode, 141 ... Insulating layer, 143 ... Protection electrode wiring, 144 ... Protection electrode wiring extraction terminal, 15 ... Fluorescence Body layer, 16 ... BM film, 17 ... Metal back (acceleration electrode), 171 ... Metal back termination, 18, 28 ... High resistance film, 181 ... High resistance film termination, 18 ... the beginning of the high resistance film, INS ... insulating film (interlayer insulating film).

Claims (8)

A plurality of scanning signal wirings extending in one direction and arranged in parallel in the other direction perpendicular to the one direction, and a plurality of scanning signal wirings extending in the other direction and arranged in parallel in the one direction so as to intersect the scanning signal wiring A back surface comprising: an image signal wiring; an interlayer insulating film disposed between the image signal wiring and the scanning signal wiring; and an electron source provided near each intersection of the scanning signal wiring and the image signal wiring. A substrate,
A phosphor layer provided corresponding to the electron source, and a phosphor film having an acceleration electrode for accelerating electrons emitted from the electron source so as to be directed to the phosphor layer; And a front substrate facing each other,
A frame that is inserted around the display area between the rear substrate and the front substrate, and holds the predetermined interval;
An image display device comprising a sealing member that hermetically seals the frame and the front substrate and the rear substrate in a sealing region,
An image display device comprising: a protective electrode that is disposed through an insulating layer that is close to the inside of the frame and covers a part of the signal wiring, and is held at a potential lower than the acceleration electrode potential.   The image display device according to claim 1, wherein the protective electrode is held at a ground potential.   The image display device according to claim 1, wherein the protective electrode includes a conductive film on an insulating glass plate.   4. The image display device according to claim 1, wherein a lead line connected to the protective electrode is provided independently of the signal line lead line.   The high-resistance film that covers the terminal end of the fluorescent film and extends in the frame direction and is disposed at a predetermined interval from the frame is provided. The image display device described.   6. The image display device according to claim 1, wherein the high-resistance film is further disposed on a portion separated from the rear substrate and the front substrate on an inner surface of the frame body. The image display device according to claim 5, wherein the high resistance film has a resistance value of 10 ⁹ Ω / □ to 10 ¹³ Ω / □.   The image display device according to claim 5, wherein the high-resistance film includes an insulating high-resistance oxide.

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