JP2000235837A - Display panel and image display device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation in light transmittance of a face plate without increasing the thickness of the face plate. SOLUTION: This display panel includes a cathode ray target 1009 for applying a high voltage formed on an inner surface side of a face plate 1006. An image is formed on the face plate by colliding an electron emitted from an electron source on the cathode ray target 1009. In this case, a potential prescribing conductive layer 1014 provided on an outer surface side of the face plate 1006 and the cathode ray target 1009 are connected with each other through a high resistant conductive film 1019. The potential prescribing conductive layer 1014 is taken as almost the same in potential as the cathode ray target 1009, by applying a high voltage between the conductive film 1019 and the cathode ray target 1009, and a current valve flowing through the potential prescribing conductive layer 1014 is restricted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel having an antistatic film formed on an outer surface of a face plate and an image display device using the same.

[0002]

2. Description of the Related Art In image surface devices using a cathode ray tube such as a CRT, research for increasing the display screen has been conducted. Accordingly, reduction in thickness, weight, and cost of the display portion have become important issues.

In response to these problems, the present inventors have studied a multi-electron source in which a number of surface conduction electron-emitting devices having various materials, manufacturing methods, and structures are arranged, and an image display device using the multi-electron source. I went.

The inventors of the present application have attempted to apply a multi-electron source by, for example, an electrical wiring method shown in FIG.
That is, a large number of surface conduction emission devices are two-dimensionally arranged,
A multi-electron source in which these elements are wired in a simple matrix as shown.

[0005] In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 shows a row direction wiring (row wiring),
4003 is a column direction wiring (column wiring). In addition, for convenience of illustration, although shown here as a 6 × 6 matrix,
Of course, the size of the matrix is not limited to this,
Elements that are sufficient for displaying a desired image are arranged and wired.

FIG. 20 is a schematic view showing a structure of a cathode ray display panel using the multi-electron source of the wiring shown in FIG. 19, wherein an outer container bottom 4005 provided with a multi-electron source 4004, an outer container frame 4007, and a phosphor are provided. Layer 4008 and metal back 4
It has a structure provided with a face plate 4006 provided with 009. A high voltage is applied to the metal back 4009 of the face plate 4006 by a high voltage power supply 4010 through a high voltage terminal 4011.

In such a multi-electron source in which the surface conduction electron-emitting devices are wired in a simple matrix, a row wiring 4002 and a column wiring 40 are required to output a desired electron beam.
03, an appropriate electric signal is applied. For example, in order to drive any one of the surface conduction electron-emitting devices in the matrix, the selection voltage Vs is applied to the row wiring 4002 of the selected row, and at the same time, the row wiring 4002 of the non-selected row is applied Applies a non-selection voltage Vns. In synchronization with this, the column wiring 400
3 is applied with a drive voltage Ve corresponding to an image signal for outputting an electron beam. According to this method, the voltage (Ve−Vs) is applied to the surface conduction type emission elements in the selected row, and the voltage (Ve−Ve) is applied to the surface conduction type emission elements in the non-selected row.
-Vns). If these voltage values Ve, Vs, Vns are set to voltages of appropriate magnitudes, an electron beam of a desired intensity is output only from the surface conduction electron-emitting device of the selected row, and a display is provided on each of the column wirings. When the drive voltage Ve according to the image signal to be applied is applied, electron beams having different intensities according to the image signal are output from each of the elements in the selected row. Further, since the response speed of the surface conduction electron-emitting device is high, if the length of time for applying the drive voltage Ve is changed, the length of time for outputting an electron beam from each device can also be changed.

The electron beam output from the multi-electron source 4004 by the application of such a voltage is applied to a metal back 4009 to which a high voltage is applied, and excites a target phosphor to emit light. Therefore, for example, if a voltage signal corresponding to image information is appropriately applied, an image display device can be obtained.

[0009]

In the image display device having such a configuration, the face plate 4006, the outer container bottom 4005, and the outer container frame 4007 are formed by the cost of the image display device, the ease of assembling the outer container, and the like. And blue plate glass (or soda lime glass) are preferably used. And, as described above, the face plate 40
When a high voltage is applied to the inner surface of the face plate 2006, a minute current flows from the inner surface to the outer surface of the face plate 4006 due to an electric field generated between the inner surface of the image display device and the GND potential. This is a current due to the cationization and movement of Na in the blue plate glass of the face plate 4006. When the Na cations move and reach the outer surface of the face plate 4006 in this manner, the shape of the glass surface changes due to the precipitation of the Na cations, and the glass surface becomes rough, or the precipitated Na cations form in the air. Phenomena such as reaction with moisture and the like to change to hydroxide and the surface to become cloudy occur, and the light transmittance of the face plate 4006 is deteriorated, and the contrast is deteriorated. Will decrease. In addition, there is a problem that the withstand voltage is deteriorated due to the movement of the Na cation.

Further, the outer surface potential of the face plate 4006 rises, and the image quality deteriorates due to the attachment of dust, or the inner surface potential changes due to the influence of the outer surface potential, and the image quality deteriorates or approaches. Also, problems such as discharge to the observer occur.

On the other hand, a transparent antistatic film 4012 is formed on the surface of the face plate 4006, and the antistatic film
There is also a method for eliminating the rise in the surface potential of the substrate 06 so that the above-mentioned problem does not occur. However, as shown in FIG. 21, when an antistatic film 4012 is formed on the surface of a glass face plate 4006 and its potential is set to the ground potential,
When the high voltage Va is applied to the cathode ray target on the back surface of the face plate, that is, the metal back 4009, the high voltage Va is applied between the front and back of the face plate 4006. When the face plate 4006 is a soda lime glass containing a large amount of Na cation, similarly to the case where the antistatic film 4012 is not provided, when the high voltage Va is applied for a long time, The cations move and are deposited on the ground electrode side, that is, on the antistatic film 4012 side.

In order to avoid this, the glass thickness of the face plate 4006 is set to several centimeters to reduce the electric field strength to reduce the moving speed of Na cations, or the content of Na cations is very small. Glass had to be used. However, the former makes it very difficult to reduce the weight, and the latter makes it very difficult to reduce the cost.

Further, as shown in FIG. 22A, a protective plate 4013 made of a resin having a lower specific gravity than glass is attached to the surface of the glass face plate 4006 to lower the potential generated at both ends of the face plate 4006. There are ways.
In the drawing, the phosphor layer is omitted for convenience. Here, assuming that the resistance and the capacitance of the face plate 4006 and the protection plate 4013 are Rg, Rp, Cg, and Cp, respectively, FIG.
The equivalent circuit of (a) is as shown in FIG.
In the equivalent circuit shown in FIG.
3 and the face plate 4006 are electrically connected without any problem, that is, they are in uniform contact, and the potential of the interface is constant regardless of the location. Actually, a certain gap or an adhesive layer may be present at the interface.However, even if the capacitance component and the resistance component are taken into consideration, they can be simplified to a similar equivalent circuit. Board 40
It was assumed as shown in FIG. Here, the face plate 4006 and the protection plate 4013
The change of the potential Vf-p in the middle of the above is as shown in FIG. That is, at the initial stage of the application of the high voltage, the potential Vi determined by the dielectric constants εg and εp of the face plate 4006 and the protection plate 4013 and the thicknesses Tg and Tp, ie, Vi = Va × {Cp / (Cp + Cg)} = Va × 1 / {1+ (εp × Tg) / (εg × Tp)} (1), and the potential Vf determined by each volume resistance value ρg, ρp with time, that is, Vf = Va × {Rg / (Rp + Rg)} = Va × ρg × Tg / (ρp × Tp + ρg × Tg) (2) The time constant τ at this time is τ = {ρg × Tg × ρp × Tp / (ρp × Tp + ρg × Tg)}
× (εp / Tp) + (εg / Tg).

Here, when soda lime glass is used for the face plate 4006 and acrylic or polycarbonate is used for the protective plate 4013, the volume resistivity ρg and ρp are respectively 10 (12 to 14) powers and 10 (15 to 17). To the power [Ω · c
m], the dielectric constants εg and εp are respectively “7” to “8”,
"2" to "3". The same thickness of each plate (Tg = Tp)
Then, Vf-p becomes the initial value Vi = (0.6 to 0.7 of Va)
(Double potential) and gradually changes to Vf ≒ 0. However, at that time, the constant τ is a very large value, and does not substantially change from the initial value Vi.

In order to prevent the image quality from deteriorating due to the movement of Na cations in the soda lime glass even when the image display device is driven for tens of thousands of hours at room temperature, the electric field applied to the soda lime glass should be about 100. [V / mm] or less. When the acceleration voltage Va is changed from several kV to 10 kV,
It is necessary to lower the initial value Vi of the voltage applied to the soda lime glass.
It is necessary to make the plate thickness Tg of No. 06 very thin or the plate thickness Tp of the protection plate 4013 thick. However, it is very difficult to reduce the thickness of the glass plate to about 2 mm or less in order to maintain atmospheric pressure resistance in terms of strength. Also, the protection plate thickness Tp is
>> In order to increase the thickness to Tg, for example, for a glass face plate having a thickness of 2 mm, a protective plate made of resin needs to be 400 mm, which makes it difficult to reduce the thickness and significantly increases the weight. Further, it is not practical even if the light transmittance of the protection plate is considered.

In addition, when the electrodes are exposed due to breakage of the panel during operation because of driving using a high voltage, it is necessary to take measures against electric shock when a person comes into contact with the exposed electrodes. Due to these problems, it has been very difficult to realize a thin, lightweight, low-cost cathode ray tube with a large screen.

The present invention has been made in view of the above conventional example, and provides a display panel which prevents a decrease in light transmittance of a face plate without increasing the thickness of the face plate, and an image display device using the same. The purpose is to do.

It is another object of the present invention to provide a display panel capable of preventing electric shock to a user and an image display device using the same.

[0019]

In order to achieve the above object, a display panel according to the present invention has the following arrangement. That is, a display panel having a face plate on which a cathode ray target for applying a high voltage is formed on an inner surface side, wherein an electron emitted from an electron source collides with the cathode ray target to form an image on the face plate. ,
A potential regulating conductive layer provided on the outer surface side of the face plate, and the potential of the potential regulating conductive layer is set to substantially the same potential as a high voltage applied to the cathode ray target to limit a current value flowing through the potential regulating conductive layer. Current limiting means.

In order to achieve the above object, the display panel of the present invention has the following configuration. That is, claims 1 to 1
7. The display panel according to claim 6, a high voltage source for applying a high voltage to the cathode ray target, input means for inputting an image signal, and the display according to the image signal input by the input means. And driving means for driving the panel by supplying electricity to the electron source of the panel.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing a preferred embodiment of the present invention in detail with reference to the accompanying drawings, features of the present embodiment will be described.

The cathode ray display device according to the present embodiment has a potential regulating conductive layer (1014 in FIG. 1) formed on the outer surface of a glass face plate (1006 in FIG. 1) on which a cathode target for applying a high voltage Va is formed on the inner surface. ), And applying the voltage of the potential regulating conductive layer to the cathode ray target at a voltage V
A current limit that regulates the voltage applied to the glass face plate to “0” or a potential close to “0” by limiting the voltage applied to the glass face plate to the same as or a potential close to the voltage Va. Means are provided.

Further, the cathode ray display device of the present embodiment
A protective plate made of a transparent member, for example, a protective plate is laminated on the glass face plate to prevent an observer from coming into contact with the potential regulating layer to which a high voltage is applied.

Further, the cathode ray display device according to the present embodiment is provided with an antistatic film on the surface of the protective plate to prevent dust from adhering and discharging to an observer.

Further, in the cathode ray display device of the present embodiment, the potential regulating conductive layer is connected to the cathode ray target by a conductor having a resistance value r, and the resistance value r is determined between the antistatic film on the surface of the transparent protective plate and the potential regulating conductive layer. Is sufficiently smaller than the resistance value R1 of Va.
/ R2 is larger than R2 at which 1 mA is obtained.

Alternatively, the potential regulating conductive layer is a transparent conductive layer. Alternatively, the potential regulating conductive layer may be a black conductor having a large number of minute pinholes having a specific aperture ratio. Alternatively, the potential regulating conductive layer may be a transparent conductive film provided on the back surface of the transparent protective plate. Alternatively, the potential regulating conductive layer may be a transparent conductive film provided on the surface of the glass face plate. Alternatively, the potential regulating conductive layer may be a transparent adhesive layer provided with conductivity.

Further, in the cathode ray display device according to the present embodiment, a multilayer film for preventing reflection of external light is formed on the surface of the protective plate, or an antiglare effect is provided.

The transparent protective plate made of resin has a sufficiently high withstand voltage as compared with soda lime glass and does not contain Na, so that the above problem does not occur even if a high potential is applied as a thin plate. Thus there is no significant increase in weight and thickness. It may be plate-shaped.

Further, this potential regulating layer can also have the effect of shielding leakage electromagnetic waves emitted from the cathode ray tube system and preventing the influence on the human body and other devices.

The protective plate can also have an explosion-proof effect of preventing crushed fragments from scattering when the glass face plate is broken. Further, the protective plate can also have an effect of reducing contrast deterioration due to external light reflection.

In addition, even if the human body comes into contact with the potential regulating conductive layer, the current limiting means limits the current that can flow into the human body and minimizes the damage.

As a current limiting means, a lead line of a potential regulating conductive layer is provided and connected to a high voltage terminal of a high voltage power supply applied to a cathode line target such as an aluminum back via a resistance element. Instead, a method of directly and electrically connecting to the cathode ray target with a conductor such as a buyer hole having a resistance value r is provided. A lead wire is provided after a conductive film having a resistance value r is continuously provided on the potential regulating conductive layer. ,
There is a method of connecting to a cathode ray target, and the like.

The details will be described below with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is a sectional view showing a configuration of an image display device according to an embodiment of the present invention.

In the figure, reference numeral 1001 denotes a substrate on which electron-emitting devices are arranged in a matrix. The face plate 1006 is made of soda lime glass and has a thickness of 3 mm.
And a phosphor layer 1008 having a thickness of about 20 μm on its inner surface.
Are formed. Further, an aluminum metal back layer 1009 having a thickness of about 1000 mm is formed so as to cover the phosphor layer 1008.
Are formed. The high voltage terminal 1011 is connected to the aluminum metal back 1009. Also,
On the surface of the face plate 1006, a potential regulating layer 1014, which is a transparent conductive film made of ITO, is deposited. As a conductive film 1019 between the potential regulating layer 1014 and the lead wire 1015, a thick film resistor having a film resistance of up to 10 9 [Ω / square cm] by mixing a glass material with ruthenium oxide particles. Is formed. At this time, the resistance between the potential regulating layer 1014 and the lead wire 1015 was a maximum of 10 9 [Ω]. In this embodiment, a thick-film resistor made of ruthenium oxide particles and a glass material is used for current limiting. However, such a current limiting material is not limited to this material. Any resistance may be used as long as it has a resistance value such as Ta-Si.
A material generally used as a high-resistance material, such as a film formed by sputtering -O, TA-Ti-Nt, or the like, may be used.

The conductive film 1019 is connected to the high voltage terminal 1011 by a lead 1015. The high voltage terminal 1011 is further connected to a high voltage power supply 1010, and the aluminum metal back 1009 and the potential regulating layer 1
014 can be applied with a high potential (for example, 10 kV).

1013 is made of acrylic (PMMA) and has a length of 3 m.
An antistatic film 1012 which is a transparent conductive film made of ITO is deposited on the surface of a protective plate having a thickness of m. The aforementioned transparent potential regulating layer 1014 and antistatic film 1012 are not limited to such a deposited ITO film,
For example, a deposited film of tin oxide or indium oxide, or a solution containing them may be applied and then heated to form a film.

When the high-voltage power supply 1010 is turned on in this state, the capacitance C of the protective plate 1013 and the conductive film 101
9, the potential defining layer 1014
Is approaching a high potential. The capacitance C of the protection plate 1013 of this embodiment is about 2000 pF,
Since the resistance R of 019 is 10 9 [Ω], the potential becomes high in about 1 second. That is, each time the power is turned on / off, there is a time during which a potential difference is generated between the front side and the back side of the face plate 1006 made of soda lime glass for about 1 second, but this time does not matter.

The antistatic film 1012 is formed of the conductive rubber 1
017 is connected to the housing 1018 and the housing 101
8 is grounded. As a result, the surface potential of the protection plate 1013 is kept at the ground potential, and the surface is prevented from being charged. The periphery of the protection plate 1013 is fixed to the glass face plate 1006 by an adhesive layer 1016 having a thickness of 1 mm. As described above, a high voltage is applied to the potential regulating layer 1014 on the surface of the face plate 1006.
6 can be prevented from adhering to the dust.

The surface resistance of the antistatic film 1012 is 10 2 to 10 3 [Ω / □], and electromagnetic waves generated from inside the image display device are
06 to prevent impact on the observer and surrounding equipment.

FIG. 2 is a top view of the vicinity where the potential regulating layer 1014, the current-limiting conductive film 1019, and the lead wire 1015 are connected. Parts common to FIG. 1 described above are denoted by the same reference numerals. .

FIG. 3 is a perspective view of a display panel of the image display device according to the present embodiment, in which a part of the display panel is cut away to show the internal structure.

In the figure, 1001 is an element substrate, 1002 is a surface conduction electron-emitting device, 1003 is a row wiring, 1004 is a column wiring, 1005 is an outer container bottom (rear plate), 1019 is a side wall, 1006 is a face plate, 1005-
1006 and 1019 form an airtight container for maintaining the inside of the display panel at a vacuum.

In assembling this airtight container,
It is necessary to seal the joints of the members to maintain sufficient strength and airtightness. For example, frit glass is applied to the joints, and the joints are 400 to 5 degrees Celsius in air or nitrogen atmosphere.
Sealing was achieved by baking at 00 degrees for 10 minutes or more. A method for evacuating the inside of the hermetic container to a vacuum will be described later.

On the surface of the face plate 1006, an ITO film for forming the potential regulating layer 1014 is deposited as described above, and a protective plate 1013 provided with an antistatic film 1012 is further formed thereon by an adhesive layer 1016. Loaded and fixed.

The rear plate 1005 has a substrate 1001
Are fixed. On the substrate 1001, n × m surface conduction electron-emitting devices 1002 are formed. Here, 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 displaying high-definition television,
It is desirable to set a number of n = 3000 and m = 1000 or more. In the present embodiment, n = 3072, m
= 1024. These n × m surface conduction electron-emitting devices are arranged in a simple matrix by m row wirings 1003 and n column wirings 1004. Here, the part constituted by these 1001 to 1004 is called a multi-electron source. The manufacturing method and structure of the multi-electron source will be described later in detail.

In this embodiment, the substrate 1001 of the multi-electron source is fixed to the rear plate 1005 of the airtight container. However, when the substrate 1001 of the multi-electron source has a sufficient strength, The substrate 1001 of the multi-electron source may be used as the rear plate of the airtight container.

On the lower surface of the face plate 1007, a fluorescent film 1008 is formed. Since this embodiment is a color display device, phosphors of three primary colors of red, green, and blue used in the field of CRT are separately applied to a portion of the fluorescent film 1008. The phosphor of each color is, for example, as shown in FIG.
As shown in FIG. 2A, a black conductor 1010 is provided between stripes of the phosphor, which are separately applied in stripes. 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 to prevent the display contrast from being lowered. This is to prevent charge-up of the fluorescent film by the electron beam. Although graphite is used as a main component for the black conductor 1010, any other material may be used as long as it is suitable for the above purpose.

FIG. 4 shows how to paint the three primary color phosphors.
The arrangement is not limited to the stripe arrangement shown in FIG. 4A, but may be, for example, a delta arrangement as shown in FIG.
Other arrangements may be used. Note that when a monochrome display panel is manufactured, a single-color phosphor material may be used for the phosphor film 1008, and a black conductive material is not necessarily used.

A metal back 1009 known in the field of CRTs is provided on the surface of the fluorescent film 1008 on the rear plate side.
Is provided. The purpose of providing the metal back 1009 is
In order to improve the light utilization rate by mirror-reflecting a part of the light emitted from the fluorescent film 1008,
08, to act as an electrode for applying an acceleration voltage of an electron beam,
To act as a conductive path for the excited electrons. The metal back 1009 was formed by forming a fluorescent film 1008 on the face plate substrate 1007, smoothing the surface of the fluorescent film, and vacuum-depositing Al thereon. Note that when a fluorescent material for low voltage is used for the fluorescent film 1008, the metal back 1009 is not used.

Although not used in the present embodiment,
For the purpose of applying acceleration voltage and improving the conductivity of the fluorescent film,
A transparent electrode made of, for example, ITO may be provided between the face plate substrate 1007 and the fluorescent film 1008.

The row terminals Dx1 to Dxm and the column terminals Dy1 to DyD
The yn and the high-voltage terminal Hv are air-tightly structured electric connection terminals provided for electrically connecting the display panel to an electric circuit (not shown). These row terminals Dx1 to Dx1
xm denotes the row wiring 1003 of the multi-electron source and the column terminals Dy1 to Dy1
yn is the column wiring 1004 of the multi-electron source and the high voltage terminal Hv
Are electrically connected to the metal back 1009 of the face plate.

In order to evacuate the interior 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 raised to the power of 10 −7 [to
rr]. Thereafter, the exhaust pipe is sealed, but a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing in order to maintain the degree of vacuum in the airtight container. This getter film is, for example, B
is a film formed by heating and depositing a getter material containing a as a main component by a heater or high-frequency heating, and the inside of the airtight container is 1 × 10 −5 to 1 × 10 −7 due to the adsorption action of the getter film. The degree of vacuum is maintained at the power of [torr].

The basic configuration of the display panel according to the embodiment of the present invention and the manufacturing method thereof have been described above.

Next, a method of manufacturing the multi-electron source used for the display panel of the present embodiment will be described. The multi-electron source used in the image display device of the present embodiment is an electron source in which the surface conduction electron-emitting devices are wired in a simple matrix.
There is no limitation on the material, shape, or manufacturing method of the surface conduction electron-emitting device. However, the present inventors have found that among the surface conduction electron-emitting devices, those in which the electron-emitting portion or its peripheral portion is formed of a fine particle film have excellent electron-emitting characteristics and can be easily manufactured. Therefore, it can be said that it is most suitable for use in a multi-electron source of a high-luminance, large-screen image display device. Therefore, in the display panel of the present embodiment, a surface conduction electron-emitting device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is used. Therefore, the basic structure, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron source in which a large number of devices are arranged in a simple matrix will be described.

(Suitable Device Configuration and Manufacturing Method of Surface Conduction Emission Device) There are two typical types of surface conduction electron-emitting devices in which an electron-emitting portion or its peripheral portion is formed of a fine particle film, a flat type and a vertical type. Is raised.

(Flat-type surface conduction electron-emitting device) First, the structure and manufacturing method of a flat-surface conduction electron-emitting device will be described.

FIGS. 5A and 5B are a plan view and a sectional view, respectively, for explaining the structure of a planar surface conduction electron-emitting device.

In the figure, 1101 is a substrate, 1102 and 110
Reference numeral 3 denotes an element electrode; 1104, a conductive thin film; 1105, an electron-emitting portion formed by an energization forming process;
Is a thin film formed by the activation process. Substrate 11
01, for example, various glass substrates including quartz glass and blue plate glass, various ceramics substrates including alumina, or the above-described various substrates such as Si
A substrate on which an insulating layer made of O2 is stacked can be used.

The device electrodes 1102 and 1103 provided on the substrate 1101 in parallel with the substrate surface are formed of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
Ag and other metals, or alloys of these metals,
Alternatively, a material may be appropriately selected from metal oxides such as In2O3-SnO2, semiconductors such as polysilicon, and the like. An electrode can be easily formed by using a combination of a film forming technique such as vacuum evaporation and a patterning technique such as photolithography and etching. However, the electrode can be formed using other methods (for example, printing technique). No problem.

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 value from the range of several hundreds of angstroms to several hundreds of micrometers. Micrometer range. As for the thickness d of the device electrodes 1102 and 1103, an appropriate numerical value is usually selected from the range of several hundred angstroms to several micrometers.

A fine particle film is used for the conductive thin film 1104. The fine particle film mentioned here refers to a film containing a large number of fine particles as constituent elements (including an island-shaped aggregate). When the fine particle film is examined microscopically, usually, a structure in which the individual fine particles are spaced 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.

The particle size of the fine particles used in the fine particle film is in the range of several Angstroms to several thousand Angstroms, and particularly preferably in the range of 10 Angstroms to 200 Angstroms. Further, the thickness of the fine particle film is appropriately set in consideration of various conditions described below. That is, the device electrode 1102
Or conditions necessary for good electrical connection with 1103, conditions necessary for good energization forming described later, conditions necessary for setting the electrical resistance of the fine particle film itself to an appropriate value described later. , And so on.

More specifically, the setting is made in the range of several Angstroms to several thousand Angstroms, but the range is preferably between 10 Angstroms and 500 Angstroms.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, A
g, Au, Ti, In, Cu, Cr, Fe, Zn, S
metals such as n, Ta, W, Pb, etc .;
Oxides such as O, SnO2, In2O3, PbO, Sb2O3, etc., HfB2, ZrB2, LaB6, C
Borides such as eB6, YB4, GdB4, etc., TiC, ZrC, HfC, TaC, SiC, WC,
And other carbides, TiN, ZrN, Hf
Nitrides such as N, etc., semiconductors such as Si, Ge, etc., carbon, and the like are listed, and are appropriately selected from these.

As described above, the conductive thin film 1104 is formed of a fine particle film.
It was set so as to be included in the range of 10 3 to 10 7 [Ω / □].

The conductive thin film 1104 and the device electrode 11
Since it is desirable that the wires 02 and 1103 be electrically connected well, they have a structure in which a part of each overlaps with the other. In the example of FIG. 5, the overlapping is performed in the order of the substrate, the device electrode, and the conductive thin film from the bottom, but in some cases, the substrate, the conductive thin film, and the device electrode are stacked in the order of the bottom. No problem.

The electron emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has a higher electrical property than the surrounding conductive thin film. The crack is formed by performing a later-described energization forming process on the conductive thin film 1104. Fine particles having a particle size of several Angstroms to several hundred Angstroms may be arranged in the crack. Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion 1105, they are schematically shown in FIG.

The thin film 1113 is a thin film made of carbon or a carbon compound, and covers the electron emitting portion 1105 and its vicinity. The thin film 1113 is formed by performing an energization activation process described later after the energization forming process. This thin film 1113 is any one of single crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 [Å] or less, but preferably 300 [Å] or less. More preferred.

Since it is difficult to precisely show the actual position and shape of the thin film 1113, it is schematically shown in FIG. Further, in the plan view (a), the thin film 111 is formed.
The device from which a part of 3 is removed is shown.

The basic structure of the preferred element has been described above. In the embodiment, the following element is used.

That is, blue glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrode was 1000 [angstrom], and the electrode interval L was 2 [micrometer].

Further, Pd or PdO was used as a main material of the fine particle film, and the thickness of the fine particle film was about 100 [angstrom] and the width W was 100 [micrometer].

Next, a method of manufacturing a suitable flat surface conduction electron-emitting device will be described.

FIGS. 6A to 6D are cross-sectional views for explaining a manufacturing process of the planar type surface conduction electron-emitting device, and the notation of each member is the same as FIG.

(1) First, as shown in FIG. 6A, device electrodes 1102 and 1103 are formed on a substrate 1101. In forming these element electrodes 1102 and 1103, the substrate 1101 is sufficiently washed in advance with a detergent, pure water, and an organic solvent, and then a material for the element electrodes is deposited. As a deposition method, for example, a vacuum film forming technique such as an evaporation method or a sputtering method may be used. Thereafter, the deposited electrode material is patterned by using a photolithography / etching technique to form a pair of device electrodes 1102 and 1103 shown in FIG.

(2) Next, a conductive thin film 1104 is formed as shown in FIG. This conductive thin film 1104
In forming (a), first, an organic metal solution is applied to the substrate (a), dried, heated and baked 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 material of fine particles used for the conductive thin film. Specifically, in the present embodiment, Pd is used as a main element. In the embodiment, a dipping method is used as a coating method, but other methods such as a spinner method and a spray method may be used.

As a method of forming a conductive thin film made of a fine particle film, other than the method of applying an organic metal solution used in the present embodiment, for example, a vacuum evaporation method, a sputtering method, or a chemical vapor deposition method may be used. In some cases, a phase deposition method or the like is used.

(3) Next, as shown in FIG. 7C, the forming electrodes 1110 and 1112 are supplied from the forming power supply 1110.
The electron emitting portion 1105 is formed by applying an appropriate voltage during the period 03 and performing the energization forming process.

The energization forming treatment is to energize the conductive thin film 1104 made of a fine particle film, to appropriately break, deform, or alter a part of the conductive thin film 1104 to obtain a structure suitable for emitting electrons. This is the process of changing.
A portion of the conductive thin film made of the fine particle film that has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 110
In 5), an appropriate crack is formed in the thin film.
Note that the electrical resistance measured between the device electrodes 1102 and 1103 is significantly increased after the formation of the electron emission portions 1105 as compared to before the formation.

FIG. 7 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 in order to explain this energization method in more detail. When forming a conductive thin film made of a fine particle film, a pulse-like voltage is preferable. In the case of the present embodiment, a triangular wave pulse having a pulse width T1 is continuously generated at a pulse interval T2 as shown in FIG. Was applied. At that time, the peak value Vpf of the triangular wave pulse
Was sequentially increased in pressure. In addition, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 were inserted at appropriate intervals between the triangular-wave pulses, and the current flowing at that time was measured by the ammeter 1111.

In this embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is set to 1 [millisecond] and the pulse interval T2 is set to 10
[Milliseconds], and the peak value Vpf is set to 0.1 for each pulse.
The voltage was increased by [V]. Then, each time five triangular waves were applied, the monitor pulse Pm was inserted once.
In order not to adversely affect the forming process,
The monitor pulse voltage Vpm was set to 0.1 [V].
Then, when the electric resistance between the element electrodes 1102 and 1103 becomes 1 × 10 6 [Ω], that is, when the current measured by the ammeter 1111 when the monitor pulse is applied is 1 × 10
At the stage when the power became −7 [A] or less, the energization related to the forming process was terminated.

The above-described method is a preferable method for the surface conduction electron-emitting device of the present embodiment. For example, 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 determined. If it is changed, it is desirable to appropriately change the energization conditions accordingly.

(4) Next, as shown in FIG. 6D, an appropriate voltage is applied between the element electrodes 1102 and 1103 from the activating power supply 1112 to carry out an energizing activation process, and the electron emission is performed. Improve characteristics.

The energization activation process is a process of energizing the electron emitting 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 a member 1113.) By performing the activation process, the emission current at the same applied voltage is typically smaller than that before the activation. Specifically, it can be increased by 100 times or more.

More specifically, by periodically applying a voltage pulse in a vacuum atmosphere within the range of 10 −4 to 10 −5 [torr], the organic compound existing in the vacuum atmosphere is applied. Is deposited. The deposit 1113 is one of single-crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500 Å.
Or less, more preferably 300 [angstrom] or less.

FIG. 8A shows an example of an appropriate voltage waveform applied from the activating power supply 1112 in order to explain this energizing method in more detail. In the present embodiment, the energization activation process is performed by applying a rectangular wave of a constant voltage periodically, but specifically, the rectangular wave voltage Vac is 14
[V], pulse width T3 is 1 [millisecond], pulse interval T4
Was set to 10 [milliseconds]. Note that the above-described energization conditions 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 appropriately change the conditions accordingly.

Reference numeral 1114 shown in FIG. 6D denotes an anode electrode for capturing the emission current Ie emitted from the surface conduction electron-emitting device. The anode electrode 1114 is connected to a DC high-voltage power supply 1115 and an ammeter 1116. Note that in the case where the activation process is performed after the substrate 1101 is incorporated into a display panel, the phosphor screen of the display panel is used as the anode electrode 1114. While applying the voltage from the activation power supply 1112,
The emission current Ie is measured by the ammeter 1116 to monitor the progress of the energization activation process, and control the operation of the activation power supply 1112. Emission current Ie measured by ammeter 1116
FIG. 8B shows an example. When the pulse voltage is started to be applied from the activation power supply 1112, the emission current Ie increases with the lapse of time, but eventually saturates and hardly increases. In this way, when the emission current Ie is almost saturated, the application of the voltage from the activation power supply 1112 is stopped,
The energization activation process ends.

The above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment. If the design of the surface conduction electron-emitting device is changed, the conditions should be changed accordingly. Is desirable.

As described above, a planar surface conduction electron-emitting device shown in FIG. 6E was manufactured.

(Vertical Surface Conduction Emitting Element) Next, another typical structure of a surface conduction electron emitting element in which the electron-emitting portion or its periphery is formed of a fine particle film, that is, a vertical surface conduction electron-emitting device. The configuration of the element will be described.

FIG. 9 is a schematic cross-sectional view for explaining the basic structure of a vertical type.
02 and 1203 are device electrodes, 1206 is a step forming member,
Reference numeral 1204 denotes a conductive thin film using a fine particle film, 1205 denotes an electron-emitting portion formed by an energization forming process, 121
Reference numeral 3 denotes a thin film formed by the activation process.

The difference between the vertical type and the flat type described above is that one of the element electrodes (1202) is provided on the step forming member 1206, and the conductive thin film 1204 is provided on the side surface of the step forming member 1206. It is in the point of coating. Therefore, the element electrode interval L in the planar type shown in FIG. 5 is set as the step height Ls of the step forming member 1206 in the vertical type. Note that for the substrate 1201, the element 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 similarly used. For the step forming member 1206, an electrically insulating material such as SiO2 is used.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described.

FIGS. 10 (a) to 10 (f) are cross-sectional views for explaining the manufacturing process, and the notation of each member is the same as FIG.

(1) First, as shown in FIG.
An element electrode 1203 is formed over a substrate 1201.

(2) Next, as shown in FIG. 9B, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by stacking, for example, SiO2 by sputtering,
For example, another film formation method such as a vacuum evaporation method or a printing method may be used.

(3) Next, as shown in FIG. 9C, an element electrode 1202 is formed on the insulating layer.

(4) Next, as shown in FIG. 11D, a part of the insulating layer is removed by using, for example, an etching method, so that the element electrode 1203 is exposed.

(5) Next, as shown in FIG. 11E, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the planar type, a film forming technique such as a coating method may be used.

(6) Next, as in the case of the flat type, an energization forming process is performed to form an electron-emitting portion. (A process similar to the planar energization forming process described with reference to FIG. 6C may be performed.) (7) Next, as in the case of the planar type, the energization activation process is performed, and the electron emission section is performed. Carbon or a carbon compound is deposited in the vicinity. (A process similar to the planar energization activation process described with reference to FIG. 6D may be performed.) As described above, the vertical surface conduction electron-emitting device shown in FIG. Manufactured.

(Characteristics of Surface Conduction Emitting Element Used in Display Device) The element structure and manufacturing method of the planar and vertical surface conduction electron-emitting devices have been described above. Next, the characteristics of the element used in the display device will be described. Is described.

FIG. 11 shows typical examples of (emission current Ie) versus (device applied voltage Vf) characteristics and (device current If) versus (device applied voltage Vf) characteristics of the device used in the display device. . Note that the emission current Ie is significantly smaller than the device current If, and it is difficult to show them on the same scale. In addition, these characteristics are changed by changing design parameters such as the size and shape of the device. Therefore, each of the two graphs is shown in arbitrary units.

The elements used in the display device of this embodiment are as follows:
The emission current Ie has the following three characteristics.

First, when a voltage higher than a certain voltage (this is called a threshold voltage Vth) is applied to the element, the emission current Ie sharply increases. On the other hand, when the voltage is lower than the threshold voltage Vth, the emission current Ie increases. Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie changes depending on the voltage Vf applied to the element, the emission current Ie depends on the voltage Vf.
Size can be controlled.

Third, since the response speed of the current Ie emitted from the element is fast with respect to the voltage Vf applied to the element, the amount of charge of the electrons emitted from the element depends on the length of time during which the voltage Vf is applied. Can control.

Because of the above-described 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 pixels of a display screen, if the first characteristic is used, display can be performed by sequentially scanning the display screen. That is, a voltage equal to or higher than the threshold voltage Vth is appropriately applied to the element under driving according to the desired light emission luminance, and the threshold voltage Vth is applied to the element in the unselected state.
Apply less than voltage. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

Further, by using the second characteristic or the third characteristic, the light emission luminance can be controlled, so that a gradation display can be performed.

(Structure of a Multi-Electron Source in which Many Devices are Wiring in a Simple Matrix) Next, a structure of a multi-electron source in which the above-mentioned surface conduction electron-emitting devices are arranged on a substrate and wired in a simple matrix will be described.

FIG. 12 is a plan view of the multi-electron source used for the display panel of FIG. On the substrate, surface conduction type emission devices similar to those shown in FIG. 5 are arranged, and these devices are composed of row wiring electrodes 1003 and column wiring electrodes 1004.
Are arranged in a simple matrix. At a portion where the row wiring electrode 1003 and the column wiring electrode 1004 intersect, an insulating layer (not shown) is formed between the electrodes, and electrical insulation is maintained.

FIG. 13 shows a cross section taken along the line AA ′ of FIG.

Incidentally, the multi-electron source having such a structure is as follows.
A row wiring electrode 1003, a column wiring electrode 100
4. After forming an inter-electrode insulating layer (not shown), an element electrode of a surface conduction electron-emitting device and a conductive thin film, a row wiring electrode 1 is formed.
003 and the column wiring electrode 1004 to supply electric power to each element to perform an energization forming process and an energization activation process.

As a comparative example, an image display device in which an antistatic film was formed on the outer surface of a face plate made of soda lime glass having a thickness of 3 mm and 40 mm without a protective plate and a potential regulating layer was manufactured. The device was driven for 48 hours by applying a high voltage (10 kV) under an atmosphere of a temperature of 70 ° C. and a humidity of 85% together with the image display device according to the embodiment. The result is shown in FIG.

As described above, according to the present embodiment, it is possible to realize an image display device which is light and thin and has no deterioration in image quality.

Further, according to the display device of the present embodiment, since the current is limited to such a degree that it is safe even if it is touched, it is safe even if it is touched by a human.

[Second Embodiment] Next, the configuration of a display panel of an image display device according to a second embodiment of the present invention will be described.

FIG. 15A is a sectional view showing the structure of the face plate portion of the display panel according to the second embodiment.

In the figure, an approximately 20 μm-thick phosphor layer (not shown) is formed on the inner surface of a face plate 206 made of soda lime glass and having a thickness of 3 mm. Aluminum metal back layer 2
09 is formed. Then, the high voltage terminal 211 is connected to the aluminum metal back 209. The high voltage terminal 211 is further connected to the output of the switch 222.
The switch 222 is controlled by the controller 221 so that one of two inputs is selected and output. One of the inputs of the switch 222 has an output voltage of 1
It is connected to a 0 kV high voltage power supply 210 and the other is connected to ground. Note that the same electron source as that used in Embodiment 1 was used.

The protective plate 213 is made of polycarbonate and has a thickness of 3 mm, and on the surface thereof, an antistatic film 212 which is a transparent conductive film made of ITO is deposited. This antistatic film 21
2 is kept at the ground potential, and the face plate 206
To prevent electrification of the surface. The surface on the opposite side of the protection plate 213 has conductivity, and at least the protection plate 21
A potential regulating layer 214 having a light reflectance of 1% or less on the third side is formed.

In the second embodiment, the potential regulating layer 214
For example, as shown in FIG. 15B, a carbon paste in which a large number of openings 224 having a diameter of 20 μm are arranged at a pitch shown in FIG. This potential regulating layer 214 is connected to the output of the switch 222 via the high voltage terminal 215 and the diode 220. The outputs of the switch 222 and the high-voltage power supply 210 are controlled by the controller 221. When the power of the image display apparatus according to the second embodiment is turned off or when the housing is opened, the high-voltage power supply 21 is turned off.
The output of 0 is turned off, the ground of the input of the switch 222 is selected, and the potential defining layer 214 is grounded.

The potential regulating layer 214 and the high voltage power supply 210
Are connected in the illustrated direction by the diode 220, so that the potential of the
The output potential of the high-voltage power supply 210 is set according to the reverse characteristic of 0.

FIG. 16 is a diagram schematically showing a change in the potential of the potential defining layer 214 when the high voltage power supply 210 is turned on / off.

In the second embodiment, the reverse current is 10 μm.
By selecting a diode 220 of about A, 10 kV
In a minute unit with respect to the application of the high voltage of
The potential of 14 becomes a high voltage. However, the current that can be taken out from the potential regulating layer 214 is limited by the reverse current of the diode 220 and is a maximum of 10 μA. Therefore, even if a person touches the potential regulating layer 214, there is no fear of electric shock and the safety is ensured. .

When the high voltage power supply 210 is turned off by the controller 221, the electric charge of the potential regulating layer 214 is released by the forward characteristic of the diode 211 according to the output voltage of the high voltage power supply 210. This prevents charges from remaining on the potential regulating layer 214 for a long time,
As shown in FIG. 16, since the potential instantaneously drops, a device with higher safety can be realized.

Here, the protective plate 213 is made of the photocurable adhesive 2
19 is fixed to the glass face plate 206. Here, the refractive index of the protective plate 213 is “1.56”, the refractive index of the glass face plate 206 is “1.51”,
The refractive index of the cured adhesive is “1.54” in between. As a result, the light reflectance at each boundary surface is about 1% or less without performing any anti-reflection processing.

The reason why the photo-curing type was used as the adhesive was as follows.
For the ease of the manufacturing process, after applying an adhesive to the glass face plate 206, the protective plate 213 is loaded and irradiated with light through the protective plate 213 to be cured.

The antistatic film 212 is wrapped around the adhesive layer as shown in the figure (however, in FIG.
15 and 211, the antistatic film 212 does not extend to the temporary adhesive layer, but the portion other than the vicinity of the lead wire 215 extends to the adhesive layer.)
This prevents the high voltage application electrode or the portion where the surface potential has increased from being exposed to the surface.

Further, the light transmittance of the potential regulating layer 214 is 70%.
Therefore, the reflectance of external light reaching the phosphor layer can be reduced to half or less, and the contrast can be improved.

The potential regulating layer 214 also has the effect of shielding the leakage electromagnetic waves emitted from the cathode ray tube system and preventing the influence on the human body and other devices.

[Embodiment 3] FIG. 17 is a sectional view showing a configuration of a display panel of an image display device according to Embodiment 3 of the present invention.

In the figure, a phosphor layer 308 having a thickness of about 20 μm is formed on the inner surface of a face plate 306 made of soda lime glass, and an aluminum metal back layer 309 having a thickness of about 1000 mm is formed so as to cover the phosphor layer 308. Are formed. The high voltage terminal 311 is connected to the aluminum metal back 309. High voltage terminal 31
1 is further connected to a high voltage power supply 310 having an output voltage of 10 kV. In addition, a lead line 315 is taken out from the transparent conductive adhesive layer 316 and connected to the high voltage power supply 310 via a resistance element 321 having a resistance value of 10 7 [Ω]. Therefore, the output voltage of the high voltage power supply 210 is 10 kV
In this case, even if a person touches the surface of the face plate 306, the value of the current flowing through the lead wire 315 is suppressed to 1 mA or less, which is safe. The same element substrate 1001 as that described in the first embodiment was used as the element substrate 1001 including the electron sources wired in a matrix.

Reference numeral 313 denotes a protection plate made of polycarbonate.
The surface is roughened for antiglare, and an antistatic film 312 which is a transparent conductive film made of ITO is further deposited.
The potential of the antistatic film 312 is kept at the ground potential to prevent the surface of the substantially plate 313 from being charged. Antistatic film 312
Is connected to the housing 1018 by a conductive rubber 1017, and the housing 1018 is grounded. Thus, the potential of the surface of the protection plate 313 is kept at the ground potential, and the surface is prevented from being charged.

The protective plate 313 is made of a transparent conductive adhesive 31.
6 to adhere to the surface of the glass face plate 306
The transparent conductive adhesive layer 316 is fixed and functions as the potential regulating layer in the first and second embodiments. Here, the refractive index of the protective plate 313 is “1.56”, the refractive index of the glass face plate 306 is “1.51”, and the adhesive layer 3
The refractive index of 16 is "1.54" in the middle. As a result, the light reflectance at each boundary surface is 1% or less even if no antireflection processing is performed. Here, as the transparent conductive adhesive layer 316, a material obtained by dispersing ITO fine particles in a photocurable adhesive was used.

In addition, the conductive rubber 1017 and the housing 1018
Is surrounded by an insulating rubber 320. As a result, the creepage distance between the transparent conductive adhesive layer 316 and the antistatic film 312 or the housing 1018 can be increased to prevent unnecessary discharge.

Further, in the present embodiment, the current is limited to such a degree that it is safe for humans to touch it.

[Embodiment 4] FIG. 18 is a sectional view showing a structure of a display panel of an image display device according to Embodiment 4 of the present invention.

In the figure, a phosphor layer 408 having a thickness of about 20 μm is formed on the inner surface of a face plate 406 made of soda lime glass, and an aluminum metal back layer 409 having a thickness of about 2000 mm is formed so as to cover the phosphor layer 408. Are formed. The high voltage terminal 411 is connected to the aluminum metal back 409. On the surface of the face plate 406, a potential regulating layer 414, which is a transparent conductive film made of ITO, is deposited. The face plate 406 has a conductive via hole 415 having a resistance value r.
Is provided, and the potential regulating layer 414 is connected to the aluminum metal back 409 via the via hole 415. The high voltage terminal 411 is connected to a high voltage power supply 410 having an output voltage of 10 kV, and a high voltage supplied from the high voltage terminal 411 is applied to the aluminum metal back 409 and the potential regulating layer 414. The same element substrate 1011 as that described in the above-described embodiment was used as the element substrate 1011 provided with the electron sources wired in a matrix.

413 is a protective plate made of polycarbonate.
On its surface, an antistatic and antireflection multilayer film 412 whose outermost surface is a transparent conductive film made of deposited ITO is formed. The transparent potential regulating layer 414 and the antistatic film 412 are not limited to the deposited ITO film. For example, a deposited film of tin oxide or indium oxide, or a solution containing them is applied and then heated to form a film. You may. Here, the resistance value r of the via hole 415 depends on the antistatic film 412 and the potential regulating layer 4.
The resistance value is set to be sufficiently small as compared with the resistance value R between the fourteen elements, that is, the element voltage Vf is sufficiently small when Rg = r in the above equation (2). In the fourth embodiment, 10
The resistance value was 7th power [Ω]. Thereby, the high voltage terminal 41
Even if 10 kV is applied to 1, only a potential of 1 V or less is applied to the face plate 406. In addition, even when a person touches the potential regulating layer 414 during driving at 10 KV, the value of the current flowing therethrough is suppressed to 1 mA, which is safe.

The antistatic film 412 is made of the conductive rubber 101.
7 and connected to the housing 1018.
Is grounded. As a result, the surface potential of the protective plate 413 is maintained at the ground potential, and the surface is prevented from being charged. The protection plate 413 has its periphery fixed to the glass face plate 406 by an adhesive layer 416. With such a configuration, a high voltage is applied to the potential regulating layer 414. However, by sealing the periphery, dust can be prevented from adhering.

In each of the embodiments described above, acrylic or polycarbonate is used as the protective plate. However, the present invention is not limited to this. For example, polypropylene (PP) or polyethylene terephthalate (PET) may be used. Good.

FIG. 23 shows a structure in which image information provided from various image information sources such as television broadcasting can be displayed on a display panel using the above-mentioned surface conduction electron-emitting device as an electron source. It is a block diagram for explaining an example of a multifunctional image display device.

In the figure, reference numeral 2100 denotes the display panel according to the present embodiment, 2101 denotes a driving circuit of the display panel 2100, 2102 denotes a display controller, 2103
Is a multiplexer, 2104 is a decoder, 2105 is an input / output interface circuit, 2106 is a CPU, 210
7 is an image generation circuit, 2108, 2109 and 21
10 is an image memory interface circuit, 2111 is an image input interface circuit, 2112 and 2113
Denotes a TV signal receiving circuit, and 2114 denotes an input unit. In addition,
The display device of the present embodiment, when receiving a signal including both video information and audio information, such as a television signal, naturally reproduces audio simultaneously with the display of video. Descriptions of circuits, speakers, and the like related to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the present embodiment will be omitted. Hereinafter, the function of each unit will be described along the flow of the image signal.

The TV signal receiving circuit 2113 is a circuit for receiving a TV image signal transmitted using a radio transmission system such as radio waves or spatial optical communication. The type of the TV signal to be received is not particularly limited.
Various systems such as the NTSC system, the PAL system, and the SECAM system may be used. Further, a TV signal (for example, a so-called high-definition TV including the MUSE system) composed of a larger number of scanning lines than the above is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. Signal source. The TV signal received by the TV signal receiving circuit 2113 is output to the decoder 2104. The TV signal receiving circuit 2112 is a circuit for receiving a TV image signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. The TV signal receiving circuit 21
Similarly to 13, the type of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 2104.

Image input interface circuit 2111
Is a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner. The captured image signal is output to the decoder 2104. The image memory interface circuit 2110 includes:
This is a circuit for capturing an image signal stored in a video tape recorder (hereinafter abbreviated as VTR). The captured image signal is output to a decoder 2104. The image memory interface circuit 2109 is a circuit for taking in an image signal stored in the video disk, and the taken-in image signal is output to the decoder 2104. The image memory interface circuit 2108 is a circuit for taking in an image signal from a device storing still image data, such as a so-called still image disk, and the taken still image data is output to the decoder 2104.

The input / output interface circuit 2105 comprises:
A circuit for connecting the present display device to an external computer, a computer network, or an output device such as a printer. In addition to inputting and outputting image data, character data, and graphic information, control signals and numerical data can be input and output between the CPU 2106 included in the display device and the outside in some cases. . The image generation circuit 2107 generates display image data based on image data and character / graphic information input from the outside via the input / output interface circuit 2105, or image data and character / graphic information output from the CPU 2106. It is a circuit for performing. Within this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory for storing image patterns corresponding to character codes, and a processor for performing image processing Circuits necessary for generating an image, such as those described above, are incorporated. The display image data generated by the present circuit is output to the decoder 2104. In some cases, the input / output interface circuit 2
It is also possible to input and output an external computer network and a printer via 105.

The CPU 2106 mainly performs operations related to operation control of the display device and generation, selection and editing of a display image. For example, a control signal is output to the multiplexer 2103, and image signals to be displayed on the display panel are appropriately selected or combined. In that case, the display panel controller 2102 according to the image signal to be displayed.
A control signal is generated to appropriately control the operation of the display device such as the screen display frequency, the scanning method (for example, interlaced or non-interlaced), and the number of scanning lines in one screen.
Further, image data and character / graphic information are directly output to the image generating circuit 2107, or an external computer or memory is accessed via the input / output interface circuit 2105 to convert the image data or character / graphic information. input. The CPU 2106 may, of course, be involved in work for other purposes. For example, it may be directly related to a function of generating and processing information, such as a personal computer or a word processor. Alternatively, as described above, the input / output interface circuit 210
5 to connect to an external computer network,
For example, work such as numerical calculation may be performed in cooperation with an external device.

The input unit 2114 is for the user to input commands, programs, data, and the like to the CPU 2106. For example, in addition to a keyboard and a mouse, various input devices such as a joystick, a barcode reader, and a voice recognition device can be used. It is possible to use equipment. Decoder 210
Reference numeral 4 designates various image signals input from the above 2107 to 2113 as three primary color signals, or a luminance signal and an I signal,
This is a circuit for inversely converting to a signal. It is to be noted that the decoder 2104 desirably includes an image memory therein, as indicated by a dotted line in FIG. This is for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. In addition, the provision of the image memory facilitates the display of a still image.
Alternatively, there is an advantage that image processing and editing including image thinning, interpolation, enlargement, reduction, and synthesis can be easily performed in cooperation with the image generation circuit 2107 and the CPU 2106.

The multiplexer 2103 includes a CPU 210
The display image is appropriately selected based on the control signal input from the control unit 6. That is, the multiplexer 2103 selects a desired image signal from the inversely converted image signals input from the decoder 2104 and outputs the selected image signal to the drive circuit 2101. In that case, by switching and selecting an image signal within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen TV. . The display panel controller 2102 is a circuit for controlling the operation of the driving circuit 2101 based on a control signal input from the CPU 2106.

First, as a signal related to the basic operation of the display panel 2100, for example, a signal for controlling an operation sequence of a drive power source (not shown) for the display panel is output to the drive circuit 2101. In addition, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlaced or non-interlaced), which is related to the display panel driving method, is output to the driving circuit 2101. In some cases, a control signal related to image quality adjustment such as luminance, contrast, color tone, and sharpness of a display image may be output to the driving circuit 2101. The drive circuit 2101 is a circuit for generating a drive signal to be applied to the display panel 2100, and operates based on an image signal input from the multiplexer 2103 and a control signal input from the display panel controller 2102. .

The function of each section has been described above. With the configuration illustrated in FIG. 23, in the display device of the present embodiment, image information input from various image information sources can be displayed on the display panel 2100. Is possible. That is, various image signals such as television broadcasts are inversely converted by the decoder 2104 and then converted by the multiplexer 21.
03 is selected as appropriate and input to the drive circuit 2101. On the other hand, the display controller 2102 generates a control signal for controlling the operation of the drive circuit 2101 according to the image signal to be displayed. The driving circuit 2101 includes:
Display panel 2100 based on the image signal and the control signal
Is applied with a drive signal. Thereby, the display panel 210
At 0, an image is displayed. These series of actions are:
The CPU 2106 controls the entire system.

In the present display device, the decoder 2
An image memory built in the image processing circuit 104;
And the CPU 2106 involve not only displaying a selected one of a plurality of pieces of image information but also displaying, for example, enlargement, reduction, rotation, movement, edge emphasis, thinning, interpolation, It is also possible to perform image processing such as color conversion and image aspect ratio conversion, and image editing such as combining, deleting, connecting, replacing, and fitting. Although not particularly described in the description of the present embodiment, a dedicated circuit for processing and editing audio information may be provided as in the above-described image processing and image editing.

Therefore, the display device of the present embodiment can be used as a display device for television broadcasting, a terminal device for video conference, an image editing device for handling still images and moving images, a terminal device for computers, office work including a word processor. It is possible to combine the functions of a terminal device, a game machine, etc. by one unit, and it has a very wide range of applications for industrial or consumer use. Note that FIG. 23 merely shows an example of a configuration of a display device using the display panel 2100 using a surface conduction electron-emitting device as an electron source, and it goes without saying that the present invention is not limited to this. For example, among the components shown in FIG. 23, circuits relating to functions that are not necessary for the purpose of use may be omitted. Conversely, additional components may be added depending on the purpose of use. For example, when the present display device is applied as a video phone, it is preferable to add a transmission / reception circuit including a television camera, an audio microphone, an illuminator, and a modem to the components.

In the present display device, in particular, a display panel using a surface conduction electron-emitting device as an electron source can be easily thinned, so that the depth of the entire display device can be reduced. In addition, the display panel using the surface conduction electron-emitting device as the electron source is easy to enlarge the screen, has high brightness, and has excellent viewing angle characteristics. It is possible to display.

Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), a device including one device (for example, a copying machine, a facsimile machine) Etc.).

Further, an object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or a CPU or a CPU) of the system or the apparatus. MP
U) is also achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying such a program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. Can be.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. System) performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, The case where the CPU of the function expansion board or the function expansion unit performs part or all of the actual processing, and the function of the above-described embodiment is realized by the processing.

As described above, according to the present embodiment, a face plate made of soda-lime glass on which a cathode ray target for applying a high voltage is formed, and a transparent plate having an antistatic conductive film formed on the surface. A protective plate, a potential regulating conductive layer between the face plate and the protective plate, means for setting the potential of the potential regulating conductive layer to a prescribed potential of characteristics, and a potential of the potential regulating conductive layer to a cathode ray target. The voltage applied to the face plate can be reduced by setting the voltage to be the same as or close to the voltage applied to the face plate.

As a result, the movement of Na cations in the face plate can be suppressed, the light transmittance does not deteriorate, and a light-weight, thin, and low-cost cathode ray tube that does not deteriorate image quality for a long time is obtained.

Further, by providing current limiting means for limiting the current that can be taken out of the potential regulating conductive layer, it is possible to ensure safety when a person touches the potential regulating layer.

[0163]

As described above, according to the present invention, it is possible to prevent a decrease in light transmittance of the face plate without increasing the thickness of the face plate.

Further, according to the present invention, it is possible to provide a display panel capable of preventing electric shock to a user and an image display device using the same.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a main part of a display panel of an image display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating connection of a lead line from a potential regulating conductive layer according to the first embodiment.

FIG. 3 is a perspective view of the display panel of the image display device according to the embodiment of the present invention, in which a part of the display panel is cut away.

FIG. 4 is a plan view illustrating a phosphor array of a face plate of the display panel according to the embodiment.

FIGS. 5A and 5B are a plan view and a cross-sectional view, respectively, of the planar surface conduction electron-emitting device used in the present embodiment.

FIG. 6 is a cross-sectional view showing a step of manufacturing the planar type surface conduction electron-emitting device according to the present embodiment.

FIG. 7 is a diagram showing an applied voltage waveform during energization forming processing according to the present embodiment.

FIG. 8 is a diagram showing an applied voltage waveform (a) and a change (b) in a discharge current Ie during the energization activation process according to the present embodiment.

FIG. 9 is a cross-sectional view of a vertical surface conduction electron-emitting device used in the present embodiment.

FIG. 10 is a cross-sectional view showing a manufacturing process of the vertical surface conduction electron-emitting device of the present embodiment.

FIG. 11 is a graph showing typical characteristics of the surface conduction electron-emitting device used in the present embodiment.

FIG. 12 is a plan view of a substrate of the multi-electron source used in the present embodiment.

13 is a cross-sectional view of the substrate of the multi-electron source of FIG. 12, taken along the line AA '.

FIG. 14 is a diagram illustrating a characteristic comparison example between the display panel according to the present embodiment and a conventional display panel.

FIGS. 15A and 15B are diagrams showing a structure of a display panel according to Embodiment 2 of the present invention, wherein FIG.
(B) is a plan view of the potential regulating conductive layer.

FIG. 16 is a diagram illustrating an on / off state of a high-voltage power supply according to a second embodiment of the present invention.

FIG. 17 is a cross-sectional view illustrating a configuration of a main part of a display panel of an image display device according to a third embodiment of the present invention.

FIG. 18 is a cross-sectional view illustrating a configuration of a main part of a display panel of an image display device according to a fourth embodiment of the present invention.

FIG. 19 is a diagram in which surface conduction electron-emitting devices are connected by matrix wiring.

FIG. 20 is a perspective view of a display panel of a conventional image display device with a part thereof cut away.

FIG. 21 is a diagram illustrating a configuration of a face plate in a conventional display panel.

FIG. 22 is a diagram illustrating a problem that occurs when a potential defining layer is not provided on a face plate of a conventional display panel.

FIG. 23 is a block diagram illustrating a configuration of a multi-function image display device using a display panel according to an embodiment of the present invention.

Claims (17)

[Claims] 1. A display panel having a face plate on which a cathode ray target for applying a high voltage is formed on an inner surface side, wherein an electron emitted from an electron source collides with the cathode ray target to form an image on the face plate. A potential regulating conductive layer provided on the outer surface side of the face plate; and a current flowing through the potential regulating conductive layer, wherein a potential of the potential regulating conductive layer is set to substantially the same potential as a high voltage applied to the cathode ray target. A display panel comprising: current limiting means for limiting a value. 2. The display panel according to claim 1, further comprising a protective layer made of a transparent member on the potential regulating conductive layer. 3. The display panel according to claim 2, further comprising an antistatic film on a surface of said protective layer. 4. The potential regulating conductive layer is connected to the cathode ray target by a conductor having a resistance value r, the resistance value r is smaller than the resistance value between the antistatic film and the potential regulating conductive layer, and the high voltage 4. The display panel according to claim 3, wherein a current value flowing when is applied is suppressed to a current value on the order of microamperes. 5. The display panel according to claim 1, wherein the potential regulating conductive layer is a transparent conductive layer. 6. The display panel according to claim 1, wherein the potential regulating conductive layer is a black conductor having a plurality of openings having a predetermined aperture ratio. 7. The device according to claim 1, wherein the current limiting means includes a diode having a forward direction from the potential regulating conductive layer toward the cathode ray target.
The display panel according to any one of the above items. 8. A switch for selectively switching between a state in which a high voltage is applied to the cathode ray target and a state in which the cathode ray target is grounded; and The display panel according to claim 7, further comprising control means for applying the high voltage and grounding the cathode ray target by the switch when the power supply of the display panel is turned off. 9. The display panel according to claim 2, wherein the potential regulating conductive layer is a transparent conductive film provided on a back surface of the protective layer. 10. The display panel according to claim 1, wherein the potential regulating conductive layer is a transparent conductive film provided on a surface of a glass-like face plate. 11. The display panel according to claim 1, wherein the potential regulating conductive layer is a transparent adhesive layer having conductivity. 12. The display panel according to claim 2, wherein the protective layer has a multilayer film for preventing reflection of external light on the surface of the protective layer, or has an antiglare function. 13. The display panel according to claim 1, wherein the face plate is made of soda lime glass. 14. The display panel according to claim 1, wherein the electron source has a plurality of surface conduction electron-emitting devices. 15. The display panel according to claim 1, wherein the protection layer is a protection plate. 16. The display panel according to claim 15, wherein said protection plate is a plate made of resin. 17. The display panel according to claim 1, a high voltage source for applying a high voltage to the cathode ray target, an input unit for inputting an image signal, and an input by the input unit. A driving unit for supplying an electric current to the electron source of the display panel in accordance with the image signal and driving the electron source.