JP2000250471A - Driving device and method for multiple electron source and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable electron beams to be outputted at high speed and uniformly from a multiple electron source which is provided with many electron emitting elements wired in a matrix. SOLUTION: In the driving of a display panel 101 having the multiple electron source in which a plurality of cold cathode elements are wired with a plurality of row wirings and a plurality of column wirings in a matrix shape, a scanning circuit 102 successively selects a row-direction wiring to be driven from a plurality of row-direction wirings. Moreover, pulse width modulation signals which are to be applied to each of a plurality of column-direction wirings are outputted in synchronization with the selection of the row-direction wirings by the circuit 102 and currents in accordance with a reference signal which is to be inputted from a waveform generating circuit 107 and whose voltage level in the prescribed period of a leading part is high are outputted from a current source 109. Then, these outputs are synthesized by current switches 108 and applied to the column wirings of the panel 101.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source and an image forming apparatus to which the electron source is applied.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a hot cathode device and a cold cathode device, are known. Among these, among the cold cathode devices, for example, a surface conduction type emission device, a field emission type device (hereinafter referred to as FE type), a metal / insulating layer / metal type emission device (hereinafter referred to as MIM type), and the like are known. I have.

Further, as a surface conduction type emission element, for example, M.S. I. Elinson, Radio Eng.
Electron Phys. , 10, 1290, (1
965) and other examples described later.

The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As this surface conduction type emission element, Sn described by Elinson et al.
In addition to those using the O ₂ thin film, those using the Au thin film [G. Dittmer: “Thin Solid Fi
lms ", 9,317 (1972)] and In ₂ O ₃ / S
nO ₂ thin film [M. Hartwell and
C. G. FIG. Fonstad: "IEEE Trans.
ED Conf. , 519 (1975)] and those using carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1
No. 22 (1983)].

As a typical example of the device configuration of these surface conduction electron-emitting devices, FIG. Hartwel
1 shows a plan view of an element according to the present invention. In FIG.
Reference numeral 1 denotes a substrate, and reference numeral 3004 denotes a conductive thin film made of a metal oxide formed by sputtering. The conductive thin film 3004 is formed in an H-shaped planar shape as shown. An electron emission portion 3005 is formed by performing an energization process called energization forming described later on the conductive thin film 3004. The interval L in the figure is 0.5 to 1 [mm], and W is
It is set at 0.1 [mm]. In addition, for convenience of illustration, the electron emitting portion 3005 is shown in a rectangular shape at the center of the conductive thin film 3004, but this is merely a schematic shape, and the position and shape of the actual electron emitting portion are faithfully represented. I am not doing it.

[0006] M. In the above-described surface conduction electron-emitting device including the device by Hartwell et al., The electron-emitting portion 3005 is formed by subjecting the conductive thin film 3004 to an energization process called energization forming before electron emission.
It was common to form That is, the energization forming means energizing by applying a constant DC voltage to both ends of the conductive thin film 3004, or a DC voltage which is boosted at a very slow rate of, for example, about 1 V / min.
The electron emitting portion 30 in a state where the conductive thin film 3004 is locally destroyed, deformed or deteriorated, and is in an electrically high resistance state.
05 is formed. Note that a crack is generated in a part of the conductive thin film 3004 that is locally broken, deformed, or altered. After the energization forming, the conductive thin film 3
When an appropriate voltage is applied to 004, electrons are emitted near the crack.

[0007] Examples of the FE type are described in, for example, W.S. P.
Dyke & W. W. Dolan, "Field emi
session ", Advance in Electro
nPhysics, 8, 89 (1956) or C.I. A. Spindt, "Physical pr
operations of thin-film figure
ld emission cathodes with
molybdenium cones ", J. App.
l. Phys. , 47, 5248 (1976).

As a typical example of the FE type device configuration, FIG. A. 1 shows a cross-sectional view of a device by Spindt et al. In the figure, reference numeral 3010 denotes a substrate;
Is an emitter wiring made of a conductive material, 3012 is an emitter cone, 3013 is an insulating layer, and 3014 is a gate electrode. This device comprises an emitter cone 3012 and a gate electrode 3
By applying an appropriate voltage during 014, field emission is caused from the tip of the emitter cone 3012.

As another element structure of the FE type, FIG.
There is also an example in which an emitter and a gate electrode are arranged on a substrate substantially in parallel with the plane of the substrate, instead of the laminated structure as in 1.

As an example of the MIM type, for example,
C. A. Mead, “Operation of tu
nnel-emission Devices, J. et al. A
ppl. Phys. , 32, 646 (1961). FIG. 2 shows a typical example of an MIM type device configuration.
It is shown in FIG. This figure is a cross-sectional view.
Is a substrate, 3021 is a lower electrode made of metal, 3022 is a thin insulating layer having a thickness of about 100 Å, 302
Reference numeral 3 denotes an upper electrode made of a metal having a thickness of about 80 to 300 angstroms. In the MIM type, the upper electrode 302
By applying an appropriate voltage between the third electrode 301 and the lower electrode 3021, electrons are emitted from the surface of the upper electrode 3023.

The above-mentioned cold cathode device can obtain electrons at a lower temperature than the hot cathode device, and therefore does not require a heater for heating. Therefore, the structure is simpler than that of the hot cathode element, and a fine element can be produced. Also,
Even if a large number of elements are arranged on a substrate at a high density, problems such as thermal melting of the substrate hardly occur. In addition, unlike the hot cathode device, which operates by heating the heater, the response speed is slow, and the cold cathode device also has the advantage that the response speed is fast.

For this reason, research for applying the cold cathode device has been actively conducted.

For example, the surface conduction electron-emitting device has the advantage of being able to form a large number of devices over a large area because it has a particularly simple structure and is easy to manufacture among the cold cathode devices. Therefore, for example, Japanese Patent Application Laid-Open No.
As disclosed in 332, methods for arranging and driving a large number of elements are being studied.

As for the application of the surface conduction electron-emitting device, for example, an image forming apparatus such as an image display device and an image recording device, a charged beam source, and the like have been studied.

In particular, as an application to an image display device, for example, as disclosed in US Pat. No. 5,066,883, JP-A-2-257551 and JP-A-4-28137 by the present applicant, a surface-conduction emission device is used. An image display device using a combination of a phosphor that emits light by irradiation with an electron beam has been studied. An image display device using a combination of a surface conduction electron-emitting device and a phosphor is expected to have better characteristics than other conventional image display devices. For example, compared to a liquid crystal display device that has become widespread in recent years, it can be said that it is superior in that it does not require a backlight because it is a self-luminous type and that it has a wide viewing angle.

A method of driving a large number of FE types is disclosed in US Pat. No. 4,904,89 by the present applicant.
5 is disclosed. Further, as an example in which the FE type is applied to an image display device, for example, R.F. The flat panel display reported by Meyer et al. Is known. [R. Mey
er: “Recent Development on
Microtips Display at LET
I ", Tech. Digest of 4th In
t. Vacuum Microele-troni
cs Conf. , Nagahama, pp .; 6-9
(1991)] Further, an example in which a number of MIM types are arranged and applied to an image display device is disclosed in, for example, Japanese Patent Application Laid-Open No.
-55738.

[0017]

SUMMARY OF THE INVENTION The present inventors have developed various materials, including those described in the above-mentioned prior art.
We have tried cold cathode devices with manufacturing method and structure. Furthermore, research has been conducted on a multi-electron beam source in which a large number of cold cathode devices are arranged, and on an image display device using the multi-electron beam source.

The inventors have tried a multi-electron beam source by an electric wiring method shown in FIG. 23, for example. That is, it is a multi-electron beam source in which a large number of cold cathode devices are two-dimensionally arranged and these devices are wired in a matrix as shown.

In the figure, 4001 schematically shows a cold cathode element, 4002 shows a wiring in a row direction, and 4003 shows a wiring in a column direction. Row direction wiring 4002 and column direction wiring 400
3 actually has a finite electrical resistance,
In the drawing, they are shown as wiring resistances 4004 and 4005. The above-described wiring method is called simple matrix wiring.

Although a 6 × 6 matrix is shown for convenience of illustration, the size of the matrix is not limited to this. For example, in the case of a multi-electron beam source for an image display device, a desired image display is performed. Elements that are sufficient to perform are arranged and wired.

In a multi-electron beam source in which cold cathode elements are arranged in a simple matrix, a row-directional wiring 4002 and a column-directional wiring 400 are required to output a desired electron beam.
3 is applied with an appropriate electric signal. For example, to drive one row of the cold cathode devices in the matrix, a selection voltage Vs is applied to the row direction wiring 4002 of the selected row,
At the same time, the non-selection voltage Vns is applied to the row direction wiring 4002 of the non-selected row. In synchronization with this, the column direction wiring 4003
Is applied with a drive voltage Ve for outputting an electron beam. According to this method, wiring resistances 4004 and 4004
If the voltage drop due to 5 is ignored, the voltage of Ve-Vs is applied to the cold cathode elements of the selected row, and the voltage of Ve-Vns is applied to the cold cathode elements of the non-selected rows. V
If e, Vs, and Vns are set to voltages of appropriate magnitudes, an electron beam of a desired intensity should be output only from the cold cathode elements in the selected row, and a different drive voltage Ve is applied to each of the column wirings. If applied, each of the elements in the selected row should output a different intensity electron beam. Further, if the length of time during which the drive voltage Ve is applied is changed, the length of time during which the electron beam is output should be changed.

Therefore, a multi-electron beam source having a cold-cathode element arranged in a simple matrix wiring has various applications. For example, if an electric signal corresponding to image information is appropriately applied, it is suitable as an electron source for an image display device. Can be used.

However, in a multi-electron beam source in which cold cathode devices are arranged in a simple matrix, the following problems actually occur.

That is, when the voltage source is actually connected to the multi-electron source and driven by the above-described voltage application method, a voltage drop occurs due to the wiring resistance, so that the voltage effectively applied to each electron-emitting device is generated. The problem that it fluctuated occurred.

The first cause of the variation in the voltage applied to each element is that the wiring length differs for each electron-emitting element in the simple matrix wiring (that is, the magnitude of the wiring resistance differs for each element). Can be

Second, the wiring resistance 4004 of each part of the row wiring
Is not uniform. This occurs because the current branches and flows from the row wiring of the selected row to each of the electron-emitting devices connected to the row, and the current flowing through each of the wiring resistors 4004 is not uniform. .

Third, the voltage drop caused by the wiring resistance varies depending on the driving pattern (display pattern in the case of an image display device).

If the voltage applied to each electron-emitting device varies due to the above reasons, the intensity of the electron beam output from each electron-emitting device deviates from a desired value, which is inconvenient in application. Met. For example, when applied to an image display device, the luminance of a display image becomes non-uniform or the luminance fluctuates depending on the display image pattern.

In addition, since the voltage variation tends to become more pronounced as the size of the simple matrix increases, it also becomes a factor in limiting the number of pixels in an image display device.

As a result of earnest research in view of such points,
The present inventors have already tried a driving method different from the voltage applying method described in the section of the prior art.

That is, when driving a multi-electron beam in which the electron-emitting devices are arranged in a simple matrix wiring, the column wiring is not connected to a voltage source for applying a driving voltage Ve, but is used to output a desired electron beam. This is a method of driving by connecting a current source for supplying a necessary current. This method controls the magnitude of the emission current Ie by controlling the magnitude of the element current If.

That is, the magnitude of the current If flowing through each electron-emitting device is determined with reference to the (device current If) vs. (emission current Ie) characteristics of the electron-emitting device, and the magnitude of the current If is determined by a current source connected to the column wiring. Supply. More specifically, a memory storing (device current If) vs. (emission current Ie) characteristics, an arithmetic unit for determining the device current If to flow,
The drive circuit may be configured by combining an electric circuit such as a control current source. Among them, the control current source may use a circuit form in which the magnitude of the element current If to be passed is once converted into a voltage signal and then converted into a current by a voltage / current conversion circuit.

According to this method, even if a voltage drop occurs in the wiring resistance, it is less susceptible to the voltage drop compared to the method of driving by connecting the above-mentioned voltage source. And a great effect in reducing fluctuations.

However, the method described below also occurs in a method of driving by connecting a current source.

That is, when supplying a constant current pulse having a short time length from a controlled constant current source to a multi-electron source in which a large number of electron-emitting devices are arranged in a matrix, Almost no electrons are emitted. When the constant current pulse is continuously supplied for a relatively long period of time, electrons start to be emitted, but a long rise time is required before the electron emission starts.

FIG. 24 is a time chart for explaining this, in which b1 is a graph showing the timing for scanning the row wiring, b2 is a graph showing a current waveform output from the control constant current source, and b3 is a graph showing the current waveform. Is a graph showing the drive current that effectively flows through the electron-emitting device, and b4 is a graph showing the intensity of the electron beam emitted from the electron-emitting device. As shown in the figure, even if a short current pulse is supplied from the control current, almost no current If flows through the electron-emitting device. In addition, even when a long pulse is supplied, the drive current flowing through the electron-emitting device is a current having a large rise time.

Although the cold-cathode type electron-emitting device itself has a high-speed response performance, the waveform of the current supplied to the electron-emitting device is distorted. As a result, the waveform of the emission current Ie is also deformed. Had been done.

The above-mentioned problem has occurred for the following reason. In an electron source wired in a simple matrix, as the size of the matrix is increased, the parasitic capacitance increases accordingly. The main part of the parasitic capacitance exists at the intersection of the row wiring and the column wiring, and this equivalent circuit is shown in FIG. When the supply of the constant current I1 from the control constant current source 5001 connected to the column wiring 5003 is started, the current is initially consumed for charging the parasitic capacitance 5005,
It hardly acts as a drive current for the electron-emitting device 5004. Therefore, the effective response speed of the electron-emitting device decreases.

More specifically, in order to achieve a practical emission luminance in a display device including a cold cathode device and a phosphor, at least 1 μm is generally required for a cold cathode device serving one pixel. It is necessary to supply a drive current of about 10 to 10 mA. On the other hand, if the drive current is supplied more than necessary, the life of the cold cathode element is shortened and the power consumption is increased.

Therefore, the output current of the control constant current is controlled to an appropriate value from 1 μA to 1 mA (actually, the type, material and form of the cold cathode, the luminous efficiency of the phosphor, the acceleration voltage The optimum drive current value is determined in consideration of such factors.

On the other hand, in order to be practical as a television receiver or a computer terminal, for example, 500 × 50
It is desirable that the number of pixels is 0 or more and the screen size is 15 inches or more on a diagonal. Therefore, when a matrix wiring is formed by a film forming technique generally used at present, a wiring resistance r and a parasitic capacitance c occur as described above. And this network is r
And c have a charging time constant Tc depending on the magnitude of c. (It should be noted that, strictly speaking, the time constant of the network depends on many parameters.) If driven by a voltage source, the electron-emitting device connected in parallel with the parasitic capacitance The limit of the response speed is determined by this time constant Tc.

However, when a constant current of 1 μA to 1 mA is supplied by using the control current source as described above, the time required for charging is longer than the time constant Tc. That is, the effective response speed of the electron-emitting device becomes slower than when driven by the voltage source.

For this reason, when the light emission luminance of the display device is controlled by the pulse width driving method, the linearity of the gray scale in a low luminance area is impaired. In addition, there are cases where an observer feels unnatural when displaying a fast-moving moving image.

As described above, when the modulation signal is supplied from the control constant current source, the effect of the voltage drop generated by the wiring resistance has been greatly improved, but the effective response speed has been reduced, so that the quality of the displayed image has been reduced. Had an adverse effect. If you increase the area of the display screen or increase the number of pixels,
This problem was more pronounced because the parasitic capacitance was even greater.

Accordingly, an object of the present invention is to provide a driving device and a driving method capable of outputting an electron beam at high speed and uniformly from a multi-electron source having a large number of electron-emitting devices wired in a matrix. It is also an object of the present invention to provide a display device which has no luminance unevenness, has excellent gradation linearity, and has a high response speed.

[0046]

In order to achieve the above object, a driving apparatus for a multi-electron source according to the present invention has, for example, the following configuration. That is, a driving device for driving a multi-electron source in which a plurality of cold cathode devices are arranged in a matrix using a plurality of row wirings and a plurality of column wirings, wherein the plurality of cold cathode elements are driven in a row direction by the plurality of row direction wirings. Scanning means for sequentially selecting wiring, and a drive signal to be applied to each of the plurality of column-directional wirings in synchronization with selection of a row-directional wiring by the scanning means, wherein a signal level in a predetermined period of a leading portion thereof is increased. Driving signal applying means for applying the driving signal to the column wiring.

[0047]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First Embodiment (Structure and Manufacturing Method of Display Panel) First, the structure and manufacturing method of a display panel of an image display device to which the present invention is applied will be described with reference to specific examples. .

FIG. 9 is a perspective view of the display panel used in the embodiment, in which a part of the panel is cut away to show the internal structure.

In the figure, 1005 is a rear plate, 1006
Is a side wall, 1007 is a face plate, 1005
1007 form an airtight container for maintaining the inside of the display panel at a vacuum. When assembling an airtight container, it is necessary to seal the joints of each member to maintain sufficient strength and airtightness.For example, apply frit glass to the joints, and in air or nitrogen atmosphere, Sealing was achieved by baking at 400 to 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container to a vacuum will be described later.

The rear plate 1005 has a substrate 1001
Is fixed, but the cold cathode device 1002 is provided on the substrate.
N × M are formed. (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, N = 3000, M It is desirable to set a number equal to or greater than 1000. In the present embodiment, N = 3072 and M = 1024.)
The cold cathode elements are arranged in a simple matrix by M row-directional wirings 1003 and N column-directional wirings 1004. The portion constituted by 1001 to 1004 is called a multi-electron beam source. The manufacturing method and structure of the multi-electron beam source will be described later in detail.

In this embodiment, the multi electron beam source substrate 1001 is fixed to the rear plate 1005 of the airtight container.
01 has sufficient strength, the substrate 10 of the multi-electron beam source is used as a rear plate of the hermetic container.
01 itself may be used.

On the lower surface of the face plate 1007, a fluorescent film 1008 is formed. Since the present embodiment is a color display device, the fluorescent film 1008 has C
Phosphors of three primary colors of red, green and blue used in the field of RT are separately applied. The phosphor of each color is, for example, as shown in FIG.
As shown in (A) of FIG.
A black conductor 1010 is provided between the phosphor stripes. The purpose of providing the black conductor 1010 is to prevent the display color from shifting even if the electron beam irradiation position is slightly shifted, and to prevent the reflection of external light to prevent the display contrast from lowering. And preventing 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.

The method of applying the three primary color phosphors is not limited to the stripe arrangement shown in FIG. 10A, but may be, for example, a delta arrangement as shown in FIG. Other arrangements may be used.

When a monochrome display panel is manufactured, a monochromatic phosphor material may be used for the phosphor film 1008, and a black conductive material may not be necessarily used.

A metal back 1009 known in the CRT field 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
A part of the light emitted from the fluorescent film 1008 is specularly reflected to improve the light utilization rate, or the fluorescent film 1008
8 to protect it, to act as an electrode for applying an electron beam acceleration voltage, and to act as a conductive path for excited electrons of the fluorescent film 1008. 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 an acceleration voltage or improving the conductivity of the fluorescent film, a transparent material made of, for example, ITO is provided between the face plate substrate 1007 and the fluorescent film 1008. Electrodes may be provided.

Dx1 to Dxm, Dy1 to Dyn, and Hv are electric connection terminals having an airtight structure provided for electrically connecting the display panel to an electric circuit (not shown). Dx1 to Dxm are the row wirings 10 of the multi-electron beam source.
03, Dy1 to Dyn are the column direction wirings 1004 of the multi-electron beam source, and Hv is the metal back 1 of the face plate.
009 electrically.

In order to evacuate the inside of the hermetic container, after assembling the hermetic container, an exhaust pipe (not shown) and a vacuum pump are connected, and the inside of the hermetic container is raised to the power of 10 −7 [T
orr]. 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. The getter film is, for example, a film formed by heating and depositing a getter material containing Ba as a main component by a heater or high-frequency heating,
Due to the adsorbing action of the getter film, the inside of the airtight container is 1 × 10 −5 or 1 × 10 −7 [Torr].
Is maintained at a vacuum degree.

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

Next, a method of manufacturing the multi-electron beam source used for the display panel of the above embodiment will be described. The material, shape, and manufacturing method of the cold cathode device are not limited as long as the multi-electron beam source used for the image display device of the present invention is an electron source in which cold cathode devices are arranged in a simple matrix. Therefore, for example, a cold cathode device such as a surface conduction type emission device, an FE type, or an MIM type can be used.

However, in a situation where a display device having a large display screen and an inexpensive display device is required, among these cold cathode devices, a surface conduction type emission device is particularly preferable. That is, in the FE type, since the relative position and shape of the emitter cone and the gate electrode greatly affect the electron emission characteristics, extremely high-precision manufacturing technology is required, but this achieves a large area and a reduction in manufacturing cost. Is a disadvantageous factor. In the MIM type, it is necessary to make the thickness of the insulating layer and the upper electrode thin and uniform, which is also a disadvantageous factor in achieving a large area and a reduction in manufacturing cost. On the other hand, since the surface conduction electron-emitting device has a relatively simple manufacturing method, it is easy to increase the area and reduce the manufacturing cost. In addition, the 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 particularly 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 beam source of a high-luminance, large-screen image display device. Therefore, in the display panel of the above 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 configuration, manufacturing method and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of a multi-electron beam 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) A typical configuration of a surface conduction electron-emitting device in which an electron-emitting portion or its peripheral portion is formed from a fine particle film is a flat type or a vertical type. Kinds are given.

(Flat-Type Surface-Conduction-Type Emission Element) First, the structure and manufacturing method of a flat-type surface-conduction-type emission element will be described. FIG. 11 shows a plan view (a) and a cross-sectional view (b) for describing the configuration of a planar surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1103 are device electrodes, 1104 is a conductive thin film, 1105
Are electron-emitting portions formed by an energization forming process;
Reference numeral 113 denotes a thin film formed by the activation process.

As the substrate 1101, for example, various glass substrates such as quartz glass and blue plate glass, various ceramics substrates such as alumina, or an insulating layer made of, for example, SiO ₂ is formed on the various substrates described above. A laminated substrate or the like 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,
A material such as Ag or the like, an alloy of these metals, a metal oxide such as In ₂ O ₃ —SnO ₂ , or a semiconductor such as polysilicon may be appropriately selected and used. . To form the electrodes, for example, film forming technology such as vacuum evaporation and photolithography,
Although it can be easily formed by using a combination of patterning techniques such as etching, it may be formed by other methods (for example, printing technique).

The shapes of the device electrodes 1102 and 1103 are appropriately designed according to the application purpose of the electron-emitting device.
Generally, the electrode spacing L is usually designed by selecting an appropriate value from the range of several hundreds of angstroms to several hundreds of micrometers. It is in the range of ten micrometers. Further, regarding the thickness d of the device electrode,
Usually, an appropriate numerical value is 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 is a film containing many fine particles as a constituent element (including an island-shaped aggregate).
I mean If you examine the microparticle film microscopically, usually
A structure in which the individual fine particles are spaced apart, 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, but 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 11
02, or 1103, conditions necessary for satisfactorily performing energization forming described later, conditions necessary for setting the electric resistance of the fine particle film itself to an appropriate value described later. , And so on.

Specifically, it is set within a range of several angstroms to several thousand angstroms, and a preferable value is between 10 angstroms and 500 angstroms.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T
a, W, Pb, and other metals, PdO, S
Oxides such as nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , etc., HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ ,
Borides such as YB ₄ , GdB ₄ , etc., Ti
Carbides including C, ZrC, HfC, TaC, SiC, WC, etc., nitrides including TiN, ZrN, HfN, etc., semiconductors including Si, Ge, etc., carbon, etc. And these are appropriately selected from these.

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

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.
Although the substrate, the device electrode, and the conductive thin film are stacked in this order from the bottom, in some cases, the substrate, the conductive thin film, and the device electrode may be stacked in this order from the bottom.

The electron emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has an electrical property higher than that of the surrounding conductive thin film. The crack is formed by performing 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, 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.

The thin film 1113 is made of any one of single crystal graphite, polycrystal graphite and amorphous carbon, or a mixture thereof, and has a thickness of 500 [Å] or less, but 300 [Å] or less. Is more preferred.

Since it is difficult to accurately show the actual position and shape of the thin film 1113, it is schematically shown in FIG. Also, in the plan view (a), the thin film 11
13 shows a device in which a part of the device 13 is removed.

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

That is, a soda lime glass was used for the substrate 1101, and a Ni thin film was 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].

As a main material of the fine particle film, Pd or P
Using dO, the thickness of the fine particle film was set to about 100 [angstrom], and the width W was set to 100 [micrometer].

Next, a method of manufacturing a suitable flat surface conduction electron-emitting device will be described. (A) to (d) of FIG.
Is a cross-sectional view for explaining the manufacturing process of the surface conduction electron-emitting device, and the notation of each member is the same as in FIG.

1) First, as shown in FIG. 12A, device electrodes 1102 and 1103 are formed on a substrate 1101. Before forming, the substrate 1101
Is thoroughly washed using a detergent, pure water, and an organic solvent, and then a material for an element electrode is deposited. (As a deposition method, for example, a vacuum film forming technique such as a vapor deposition method or a sputtering method may be used.) Then, the deposited electrode material is patterned using a photolithography / etching technique.
A pair of device electrodes (1102 and 1103) shown in FIG.
To form

2) Next, a conductive thin film 1104 is formed as shown in FIG. In forming, first, an organic metal solution is applied to the substrate of (a) and dried,
After heating and baking to form a fine particle film, it is 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, P as a main element
d was used. 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. In addition, as a method of forming a conductive thin film formed of a fine particle film, other than the method of applying the organometallic solution used in the present embodiment, for example, a vacuum evaporation method, a sputtering method, a chemical vapor deposition method, or the like. May be used.

3) Next, as shown in FIG. 9C, a forming power supply
3, an appropriate voltage is applied, and an energization forming process is performed to form the electron-emitting portion 1105. The energization forming process refers to a conductive thin film 1104 made of a fine particle film.
Is a process in which a current is applied to a part of the structure to break, deform, or alter the structure of the structure, thereby changing the structure to a structure suitable for emitting electrons. In a portion of the conductive thin film made of the fine particle film which has been changed to a structure suitable for emitting electrons (that is, the electron emitting portion 1105), an appropriate crack is formed in the thin film. Note that the electron emission unit 1105
As compared with before the formation, the electrical resistance measured between the device electrodes 1102 and 1103 greatly increases after the formation.

FIG. 13 shows an example of an appropriate voltage waveform applied from the forming power supply 1110 in order to explain the 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 this 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 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 the embodiment, for example, in a vacuum atmosphere of about 10 −5 [torr], for example, the pulse width T1 is 1 [millisecond], the pulse interval T2 is 10 [millisecond], and the peak value Vpf is The voltage was increased by 0.1 [V] for each pulse. Then, the monitor pulse Pm was inserted at a rate of one every time five triangular waves were applied. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. Then, when the electric resistance between the element electrodes 1102 and 1103 becomes 1 × 10 6 [ohm], that is, the current measured by the ammeter 1111 when the monitor pulse is applied becomes 1 × 10 −7 [A] or less. At this stage, the energization related to the forming process was terminated.

The above 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 distance L between the device electrodes is changed. In such a case, it is desirable to appropriately change the energization conditions accordingly.

4) Next, as shown in FIG.
The device electrodes 1102 and 1103 are supplied from the activation power source 1112.
During the energization activation process, apply an appropriate voltage during
Improve electron emission characteristics. The energization activation process refers to the electron emission portion 11 formed by the energization forming process.
This is a process of energizing under conditions 05 to deposit 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.

Specifically, 10 minus the fourth power to 1
By applying a voltage pulse periodically in a vacuum atmosphere within the range of 0 to the fifth power [torr], carbon or a carbon compound originating from an organic compound existing in the vacuum atmosphere is deposited. The deposit 1113 is any of single crystal graphite, polycrystalline graphite, and amorphous carbon, or a mixture thereof, and has a thickness of 500.
[Angstrom] or less, more preferably 300 [angstrom] or less.

FIG. 14A shows an example of an appropriate voltage waveform applied from the activation power supply 1112 in order to explain the energization 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]. 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 change the conditions accordingly.

An anode electrode 1114 shown in FIG. 11D is for capturing an emission current Ie emitted from the surface conduction electron-emitting device, and is connected to a DC high voltage power supply 1115 and an ammeter 1116. (Note that the substrate 1101
When the activation process is performed after the display panel is incorporated in the display panel, the phosphor screen of the display panel is connected to the anode electrode 1114.
Used as While the voltage is applied from the activation power supply 1112, the ammeter 1116 measures the emission current Ie to monitor the progress of the energization activation process.
12 is controlled. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG. 14B. When the pulse voltage is started to be applied from the activation power supply 1112, the emission current Ie increases with the passage of time, but eventually saturates. And hardly increase. As described above, when the emission current Ie is substantially saturated, the application of the voltage from the activation power supply 1112 is stopped, and the energization activation process ends.

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, the conditions should be changed accordingly. desirable.

As described above, the plane type surface conduction electron-emitting device shown in FIG.

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

FIG. 15 is a schematic cross-sectional view for explaining the basic structure of the vertical type.
202 and 1203 are device electrodes, 1206 is a step forming member, 1204 is a conductive thin film using a fine particle film, 1205
Are electron-emitting portions formed by an energization forming process;
213 is 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.
Is the step height L of the step forming member 1206 in the vertical type.
s. In addition, the substrate 1201, the element electrode 1
202 and 1203, conductive thin film 1 using fine particle film
204, the materials listed in the description of the planar type can be used in the same manner. For the step forming member 1206, an electrically insulating material such as SiO ₂ is used.

Next, a method of manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 16A to 16F are cross-sectional views for explaining a manufacturing process.
Same as 5. (1) First, as shown in FIG.
An element electrode 1203 is formed thereover. (2) Next, as shown in FIG. 2B, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by laminating, for example, SiO2 by a sputtering method. However, another film forming method such as a vacuum evaporation method or a printing method may be used. (3) Next, as shown in FIG. 3C, an element electrode 1202 is formed on the insulating layer. (4) Next, as shown in FIG. 3D, a part of the insulating layer is removed by using, for example, an etching method, and the device electrode 1 is removed.
Expose 203. (5) Next, as shown in FIG. 5E, a conductive thin film 1204 using a fine particle film is formed. For the formation, as in the case of the flat 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 emission portion. (FIG. 12
What is necessary is just to perform the same process as the planar energization forming process described using (c). (7) Next, as in the case of the flat type, a current activation process is performed to deposit carbon or a carbon compound near the electron emission portion. (The same process as the planar energization activation process described with reference to FIG. 12D may be performed.)

As described above, the vertical surface conduction electron-emitting device shown in FIG.

(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. 17 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 element current If, and it is difficult to show the same current on the same scale.
Since these characteristics are changed by changing design parameters such as the size and shape of the element, the two graphs are shown in arbitrary units.

The element used in the display device has the following three characteristics regarding the emission current Ie.

First, a certain voltage (this is referred to as a threshold voltage Vth
When a voltage of the above magnitude is applied to the element, the emission current Ie sharply increases. On the other hand, at a voltage lower than the threshold voltage Vth, the emission current 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.
The magnitude of e can be controlled.

Third, since the response speed of the current Ie emitted from the element is faster than 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 characteristics, the surface conduction electron-emitting device could 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,
The driving element has a threshold voltage Vt according to a desired light emission luminance.
h or higher, and a voltage lower than the threshold voltage Vth is applied to the non-selected elements. By sequentially switching the elements to be driven, the display screen can be sequentially scanned and displayed.

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

(Structure of a multi-electron beam source in which a large number of elements are arranged in a simple matrix) Next, a structure of a multi-electron beam source in which the above-mentioned surface conduction electron-emitting elements are arranged on a substrate and arranged in a simple matrix will be described.

FIG. 18 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate, surface conduction type emission devices similar to those shown in FIG. 11 are arranged.
And the column-directional wiring electrodes 1004 are arranged in a simple matrix. An insulating layer (not shown) is formed between the row-directional wiring electrodes 1003 and the column-directional wiring electrodes 1004 where they intersect, so that electrical insulation is maintained.

FIG. 19 is a sectional view taken along the line AA ′ in FIG.
Shown in

The multi-electron source having such a structure is as follows.
After previously forming a row direction wiring electrode 1003, a column direction wiring electrode 1004, an interelectrode insulating layer (not shown), and a device electrode and a conductive thin film of a surface conduction electron-emitting device on a substrate,
Row direction wiring electrode 1003 and column direction wiring electrode 1004
The device was manufactured by supplying power to each element through the device and performing an energization forming process and an energization activation process.

Next, a driving method and a correction method of the image display device, which is the subject of the present invention, will be described with reference to FIG.

In the figure, the display panel 101 is connected to an external electric circuit via terminals Dx1 to Dxm and Dy1 to Dyn. A high-voltage terminal Hv on the face plate is also connected to an external high-voltage power supply Va to accelerate emitted electrons. The terminals Dx1 to Dxm are used to sequentially drive the multi-electron beam sources provided in the above-described panel, that is, the surface conduction electron-emitting devices arranged in a matrix of M rows and N columns, one row at a time. Are applied. On the other hand, terminals Dy1 to Dy1
A modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting device in one row selected by the scanning signal is applied to yn.

Next, the scanning circuit 102 will be described.
The scanning circuit 102 includes M switching elements therein. Each switching element selects either the output voltage of the DC voltage source Vx or 0 [V] (ground level), It is electrically connected to the terminals Dx1 to Dxm. Each switching element controls a control signal Tscan output from the control circuit 103.
It operates based on
It is possible to easily configure by combining the switching elements as described above.

In the present embodiment, the DC voltage source Vx is scanned based on the characteristics of the surface conduction electron-emitting device illustrated in FIG. 17 (electron emission threshold voltage is 8 [V]). It is set so as to output a constant voltage of 7 [V] so that the drive voltage applied to the element not having the voltage is equal to or lower than the electron emission threshold voltage.

The control circuit 103 has a function of matching the operation of each unit so that an appropriate display is performed based on an image signal input from the outside, and based on a synchronization signal Tsync described below. , T for each part
scan and Tsft, and Tmry and Tmod control signals.

As is well known, the synchronization signal Tsync is composed of a vertical synchronization signal and a horizontal synchronization signal, but is shown here as a Tsync signal for convenience of explanation. On the other hand, a video signal (luminance component) is input to the shift register 104.

The shift register 104 is for serially / parallel-converting the digital signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 103. Works. (That is, the control signal Tsft may be rephrased as a shift clock of the shift register 104.) The data of one line of the serial / parallel-converted image (corresponding to the drive data of N electron-emitting devices) is , Id1 to Idn are output from the shift register 104 as N parallel signals.

The latch circuit 105 is a storage device for storing data for one line of an image for a required time only.
The contents of Id1 to Idn are stored as appropriate according to the control signal Tmry sent from the control circuit 103. The stored contents are output as Id′1 to Id′n and input to the pulse width modulation circuit 106.

The pulse width modulation circuit 106 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices in accordance with each of the image data Id′1 to Id′n.
Its output is connected to the gate of the switch through terminals Id "1 through Id" n. Then, a voltage signal having a pulse width corresponding to the data is output in accordance with the timing signal Tmod from the 103 control circuit.

The current switch 108 is a p-channel MOSF
ET is used to switch the output current of the current source 109 between the display panel 101 side and the ground side by the output of the pulse width modulation circuit.

The waveform generation circuit 107 generates a current control waveform according to the synchronization signal Tscan from the control circuit 103, and outputs the generated current control waveform to the current source 109. The waveform generation circuit 107 will be described with reference to FIG.

FIG. 2A is a diagram showing the configuration of the waveform generation circuit. As shown in FIG. 2A, the waveform generation circuit 107 of the present embodiment includes a timer 201 and a voltage source a2.
02, a voltage source b203, and a changeover switch 204. The timer 201 is reset by the scanning control signal Tscan.
During the period of chg, the changeover switch 204 is set to the voltage source a20.
Switch to direction 2. Then, after Tchg, the switch 204 is switched to the voltage source b203. The changeover switch 204 can be easily configured by combining an FET, a transistor, and the like, and can switch at a high speed. Voltage source a202 and voltage source b203
Are DC power supplies for outputting Vchg and Vdrv, respectively. Here, the method of calculating Vchg and Vdrv will be described later.

By these operations, the waveform generation circuit 107
Is as shown in FIG. 2B. Where T
sel represents the selection time of one scan line (one cycle of Tscan).

Next, the current source 109 will be described with reference to FIG. The current source 109 includes n current sources 301 as shown in FIG.
n are all commonly connected, and the output waveform of the waveform generation circuit 107 is connected. Each current source 301 is shown in FIG.
The current mirror circuit shown in FIG. This circuit includes an operational amplifier 302, an NPN transistor 303, a PNP transistor 304, and a setting resistor 305, and outputs an output current Iout with respect to a control voltage Vin.
Is represented by the following equation: Iout = Vin / Ri (Equation 1)

Next, a method of calculating the voltage setting values Vchg and Vdrv in the above-described 107 waveform generating circuit will be described.

As described with reference to FIG. 17 at the beginning of the embodiment, the electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, FIG.
As is clear from the graph of Ie of FIG. 7, a clear threshold voltage Vth (8 in the device of the present embodiment)
[V]]), and electron emission occurs only when a voltage equal to or higher than Vth is applied.

For a voltage equal to or higher than the electron emission threshold, the emission current changes in accordance with the change in the voltage as shown in the graph of FIG. The material and configuration of the electron-emitting device,
By changing the manufacturing method, the electron emission threshold voltage Vt
Although the value of h and the degree of change of the emission current with respect to the applied voltage may change, the following can be said in any case.

That is, when a pulse-like voltage is applied to the present element, for example, as shown in FIG. 8A, application of a voltage equal to or lower than the electron emission threshold does not cause electron emission.
When a voltage higher than the electron emission threshold is applied as in (b), an electron beam is output.

In the present embodiment, specifically, the element current If is controlled by applying a voltage (for example, 7 V) lower than the threshold by the scanning circuit and applying a voltage higher than the threshold by the current output. As a result, Ie is uniquely determined as shown in FIG. 17, and an electron beam can be emitted in accordance with the video signal.

From these facts, referring to Vdrv, this is a set voltage corresponding to the element current If necessary for the original electron emission after the completion of the charging of the parasitic capacitance as described above. That is, for example, it is assumed that it is necessary to output an emission current Ie of 1.5 μA from the surface conduction electron-emitting device in order to achieve a desired luminance of the display device.
In this case, as is clear from the characteristic graph of FIG. 17, the device current If may be passed through the surface conduction type emission device by 1.2 mA. Therefore, the output current of the current source 109 is set to 1.2
You can control it to a milliamp. That is, from the above (Equation 1), Vdrv = Ri × l. It is determined by 2 mA. At this time, from FIG.
Will be applied.

Next, referring to Vchg in this case, this is a set voltage corresponding to supplying a charge amount necessary for charging the above-mentioned parasitic capacitance. First,
Since the modulation circuit is connected to each column wiring, the sum of the parasitic capacitances 上 の c on one column wiring is m elements on one column wiring (the row direction wiring and the There is a crossing part), and it can be obtained by the following equation. As described above, the voltage of the lower wiring to be charged is 14V because the element requires a voltage of 14V. If the selection voltage 7V of the scanning wiring is subtracted, 14V-7V = 7V. This is a value that does not take into account the voltage drop on the scanning wiring. If the current is actually driven, a larger voltage is required depending on the location of the screen. That is, the above 7V
Is the minimum required column wiring voltage.

From this, the amount of charge required for charging is given by Q = c × m × 7. Further, in order to perform charging in the time of Tchg shown in FIG. 2, a necessary current Ichg can be expressed by Ichg = Q / Tchg = 7 × c × m / Tchg. Here, Tchg must be at least Tscan / k or less, assuming that the required number of gradations is k, in order not to lower the gradation of the image. Then, from (Equation 1), the control voltage Vch required to output Ichg from the current source 109 is obtained.
g is obtained by Vchg = 7 × c × m × Ri / Tchg.

FIG. 26 is a diagram showing output waveforms at various parts in FIG. Tscan shown in (a) is Tsync
, And indicates the switching timing of the scanning row. Tmod shown in (b)
Represents a period during which the pulse width modulation circuit 106 can output a pulse. Id ″ n shown in (c) indicates the output waveform of the n-th terminal of the pulse width modulation circuit 106. That is,
The latch circuit 105 has a pulse width based on the n-th digital value. (D) represents an output current waveform of the current source 109, and a waveform according to the current control waveform from the waveform generation circuit 107 described with reference to FIG. 2 is output. (E) is Dy
n indicates the applied voltage to the n, and Id ″ shown in (c)
While the pulse of n is being output, the output current of the current source 109 shown in (d) is applied to the terminal dyn.

As a result of trial production of an image display apparatus having the above-described configuration and settings, it was possible to obtain an image having a small luminance distribution, a high linearity of gradation, and a high responsiveness to a moving image.

In this embodiment, the waveform generation circuit 10
Although an example realized by switching between two types of voltage sources has been described as an example of the seventh example, the configuration is not limited to this. The configuration does not matter as long as such a voltage waveform can be obtained.

The above-mentioned video signal may be analog or digital, but a digital signal whose data processing is easier is adopted in this embodiment. Further, as the serial / parallel conversion means, a shift register which can easily process digital signals is employed, but the present invention is not limited to this.

As described above, according to the present embodiment, the deterioration of the gradation due to the parasitic capacitance on the multi-electron source wiring can be reduced even in the current driving method by a simple method without providing a special charging circuit or the like. It is possible to realize an excellent image display device which can be improved, has a small luminance distribution, has high gradation linearity, and has a high responsiveness to moving images.

<Second Embodiment> Next, a second embodiment according to the present invention will be described. In the first embodiment, the application of the present invention to gradation display by pulse width modulation has been described. In the second embodiment, application to gradation display by amplitude modulation will be described. . The structures of the electron-emitting device and the panel according to the second embodiment are the same as those of the first embodiment, and a description thereof will be omitted.

The configuration of the drive circuit according to the present embodiment will be described with reference to FIG. 4, a display panel 101,
Scanning circuit 102, control circuit 103, shift register 10
4. The latch circuit 105 is the same as that of the first embodiment, and the same reference numerals are given and the description is omitted.

Next, the amplitude modulation circuit 201 will be described with reference to FIG. The amplitude modulation circuit 201 includes the latch circuit 1
One line of image data Id'l to Id 'from 05
n is output to the V / I conversion circuit 403 through Id ″ 1 to Id ″ n.
As shown in the figure, it is composed of n DA converters 501.

The reference voltage Vr of the DA converter 501
The ef and the input terminal of the conversion start clock ST are respectively connected to the n terminals by a common line, and are connected to the output of the waveform generation circuit 402 and the control clock Tmod. Then, a voltage value corresponding to the data is output in accordance with the timing signal Tmod from the control circuit 103. The reference voltage Vref specifies the full span of the output of the DA converter. That is, when a full luminance signal is input to Id′1 to Id′n, the output voltage Vo of the DA converter 501 is set.
ut becomes equal to Vref.

Next, the V / I conversion circuit 403 will be described with reference to FIG. The actual configuration of the V / I conversion circuit 403 is such that the inputs Vin of the n individual V / I conversion circuits 601 are the outputs Id ″ 1 to Id ″ of the amplitude modulation circuit 401, respectively.
n and a current value according to the voltage amplitude
Output to t. The circuit configuration of the individual V / I conversion circuit 601 is the same as that of the current source circuit shown in FIG. 3B, and the current value Iout output with respect to the input voltage Vin is as follows: Iout = Vin / Ri (Expression 2) is represented by The output Iout is output to the display panel 101.
Column wirings Dy1 to Dyn.

Next, the waveform generation circuit 402 will be described with reference to FIG. FIG. 7A shows the configuration of the waveform generation circuit 402. The counter 701 counts up by an internal clock, and is reset by a synchronization signal Tscan from the control circuit 103. The data of the counter 701 is connected to an address line of the waveform memory 702, and waveform data stored in advance is output from the waveform memory 702. The waveform data (digital) output from the waveform memory 702 is input to a DA converter 703, and is converted into an analog voltage value (not shown) in synchronization with the clock of the above-described counter. Is output as the reference voltage Vref of the detector 501.

FIG. 7B shows waveforms actually output based on these configurations and operations. Vc in FIG.
The numerical values of hg, Vdrv, Tchg, and Tscan are the same as those of the first embodiment, but are briefly described as follows. From FIG. 17, assuming that the emission current required for the highest luminance is 1.5 μA as in the first embodiment, the element voltage to be applied at this time is 14 V, so the applied voltage of the column wiring is 7 V And the subsequent calculations are the same as in the first embodiment. Thus, Vch
If g is determined, the output of the waveform generator is applied to the reference of the DA conversion, so that the voltage necessary for charging the parasitic capacitance is applied to the column wiring according to the voltage value of the amplitude modulation (charging). Is also proportional to the modulation voltage).

ΔTchg limits the rising angle of the waveform in order to suppress the occurrence of a ringing voltage due to the presence of a parasitic inductance in a circuit or a multi-electron source. Of 1
It was set to about / 10. As in the second embodiment,
When the waveform memory 702 is used as the waveform generation circuit 402, an arbitrary waveform can be easily generated for achieving the object of the present invention.

FIG. 27 is a diagram for explaining signals of respective parts shown in FIG. Tscan and Tmod shown in (a) and (b) are the same as in the first embodiment (FIG. 26).
(C) is the value of Id'n, that is, n of the latch circuit 105.
It represents a digital value which is the second latch data (a value corresponding to a video signal). (D) indicates Vref generated by the waveform generation circuit 402 and provided to the amplitude modulation circuit 401. In FIG. 27, (b) of FIG.
The expression of the rising angle as described in (1) is omitted. (E) represents Id''n which is the output voltage of the n-th terminal of the amplitude modulation circuit 401. The output voltage changes according to the magnitude of the input digital value (Id'n) while maintaining the Vref waveform shape. The V / I conversion circuit 403 receives a voltage signal as shown in (e), outputs a current corresponding to the voltage signal, and outputs a corresponding terminal (Dy
Appropriate voltages will be applied to 1 to n).

As a result of trial production of an image display apparatus having the above-described configuration and settings, it was possible to obtain an image having a small luminance distribution, a high linearity of gradation, and a good response to a moving image.

In the second embodiment, as the example of the waveform generation circuit 402, one realized by a combination of a digital memory and a DA converter has been described. However, the configuration is not limited to this. Any configuration can be used as long as the above-described voltage waveform is obtained, such as waveform generation by an analog circuit. It is also possible to apply the configuration of the waveform generation circuit (FIG. 2) shown in the first embodiment. Of course, the waveform generation circuit of the second embodiment can be applied to the first embodiment.

Although the above-mentioned video signal may be analog or digital, a digital signal whose data processing is easier is employed in this embodiment. Further, as the serial / parallel conversion means, a shift register which can easily process digital signals is employed, but the present invention is not limited to this.

According to the present embodiment, similarly to the first embodiment, the deterioration of gradation due to the parasitic capacitance on the multi-electron source wiring can be reduced by a simple method without providing a special charging circuit or the like. , The luminance distribution was small, the gradation linearity was high, and an excellent image display device with good responsiveness to moving images was realized.

That is, according to each of the above embodiments, when driving a multi-electron source in which cold cathode devices are wired in a matrix,
By controlling the control current source with a preset waveform (the waveform shown in FIG. 2 or FIG. 7) and supplying the drive current, the parasitic capacitance can be charged at high speed. For this reason, it becomes possible to make an electron-emitting device respond quickly,
In addition, since the current language is used, the driving can be performed without being affected by the wiring resistance. Therefore, the image forming apparatus to which the present embodiment is applied has excellent gradation linearity, and does not give an unnatural feeling even when a moving image is displayed. In particular, even in a large-screen display device, excellent quality images can be displayed without adding a circuit for charging a parasitic capacitance.

[0152]

As described above, according to the present invention, it is possible to output an electron beam at high speed and uniformly from a multi-electron source having a large number of electron-emitting devices wired in a matrix.

Further, it is possible to provide a display device which has no luminance unevenness, has excellent gradation linearity, and has a high response speed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a drive circuit according to a first embodiment.

FIG. 2 is a diagram illustrating a configuration example and an output waveform example of a waveform generation circuit according to the first embodiment.

FIG. 3 is a diagram illustrating a circuit configuration example of a current source according to the first embodiment.

FIG. 4 is a diagram illustrating a configuration example of a drive circuit according to a second embodiment.

FIG. 5 is a diagram illustrating an amplitude modulation circuit according to a second embodiment.

FIG. 6 is a diagram illustrating a V / I conversion circuit according to a second embodiment.

FIG. 7 is a diagram illustrating a configuration example and an output waveform example of a waveform generation circuit according to a second embodiment.

FIG. 8 is a diagram illustrating an element applied voltage.

FIG. 9 is a perspective view of the image display device according to the embodiment of the present invention, in which a part of a display panel is cut away.

FIG. 10 is a plan view illustrating a phosphor array of a face plate of a display panel.

11A and 11B are a plan view and a cross-sectional view, respectively, of a planar surface-conduction emission type electron-emitting device used in the embodiment.

FIG. 12 is a cross-sectional view showing a manufacturing process of the planar type surface conduction electron-emitting device.

FIG. 13 is a diagram showing an applied voltage waveform during the energization forming process.

FIG. 14 shows an applied voltage waveform (a) at the time of energization activation processing,
It is a figure showing change (b) of discharge current Ie.

FIG. 15 is a sectional view of a vertical surface conduction electron-emitting device used in the embodiment.

FIG. 16 is a cross-sectional view showing a step of manufacturing a vertical surface conduction electron-emitting device.

FIG. 17 is a view showing typical characteristics of the surface conduction electron-emitting device used in the embodiment.

FIG. 18 is a plan view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 19 is a partial cross-sectional view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 20 is a view showing an example of a general surface conduction electron-emitting device.

FIG. 21 is a diagram showing an example of a general FE type element.

FIG. 22 is a diagram illustrating an example of a general MIM element.

FIG. 23 is a diagram schematically showing a multi-electron beam source wired in a matrix.

FIG. 24 is a timing chart for explaining a problem in a case where a current source is connected to the circuit shown in FIG. 23 for driving.

FIG. 25 is a diagram illustrating a problem in a case where a current source is connected to the circuit illustrated in FIG. 23 and driven.

FIG. 26 is a diagram illustrating signals of respective units illustrated in FIG. 1;

FIG. 27 is a diagram illustrating signals of respective units illustrated in FIG. 4;

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 641 G09G 3/20 641C H04N 5/68 H04N 5/68 BF Term (Reference) 5C058 AA11 AB02 BA01 BA06 BA07 BA22 BA25 BB03 BB25 5C080 AA08 BB05 CC03 DD05 DD08 EE29 EE30 FF12 GG08 JJ02 JJ04 JJ05 JJ06 5C094 AA03 AA13 AA14 AA15 BA21 BA32 CA19 CA24 DA13 DB04 EA04 EA05 EB05 EB02

Claims (22)

[Claims] 1. A driving device for driving a multi-electron source in which a plurality of cold cathode devices are arranged in a matrix by using a plurality of row wirings and a plurality of column wirings, wherein the plurality of cold cathode elements are driven from the plurality of row direction wirings Scanning means for sequentially selecting the row-direction wirings, and a driving signal to be applied to each of the plurality of column-direction wirings in synchronization with the selection of the row-direction wirings by the scanning means. And a driving signal applying means for applying the driving signal to the column wiring at a higher height. 2. The multi-electron source according to claim 1, wherein the drive signal applying unit detects a leading portion of the drive signal based on a switching timing of selection of a row wiring by the scanning unit. Drive. 3. The driving signal applying unit has a first voltage level for a predetermined period from a switching timing of selection of a row wiring by the scanning unit, and a second voltage level lower than the first voltage level in another period. Waveform generating means for generating a reference signal having a voltage level of; and a pulse width modulating means for generating and outputting a pulse signal obtained by pulse width modulating the video signal in synchronization with selection of a row wiring by the scanning means. 2. The multi-electron according to claim 1, further comprising: an application unit configured to apply a signal for driving the column wiring based on a voltage signal obtained by synthesizing the reference signal and the pulse signal. 3. Source drive. 4. The driving device according to claim 3, wherein the applying unit includes a current source that outputs a current value according to the voltage signal. 5. The driving signal applying unit has a first voltage level for a predetermined period from a switching timing of selection of a row wiring by the scanning unit, and a second voltage level lower than the first voltage level in another period. A waveform generating means for generating a reference signal having a voltage level of; and an amplitude modulation means for generating and outputting an amplitude-modulated signal obtained by amplitude-modulating a video signal in synchronization with selection of a row-direction wiring by the scanning means; 2. The multi-electron source driving device according to claim 1, further comprising: a current source having a current value based on the reference signal and the pulse signal and outputting a current for driving the column wiring. 3. . 6. The waveform generating unit includes: a first voltage source that generates the first voltage level; a second voltage source that generates the second voltage level; and a switching timing of a row wiring in the scanning unit. 6. A selecting means for selecting an output of the first voltage source for a predetermined period from a predetermined period, and selecting an output of the second voltage source for another period. Drive device for multi-electron source. 7. The waveform generating means includes: a counter reset at a switching timing of the scanning circuit; a memory addressed by the counter to output waveform data stored in advance; and a waveform data output from the memory as a voltage. The driving apparatus for a multi-electron source according to any one of claims 3 to 5, further comprising: a D / A converter that converts the signal into a reference signal. 8. The driving device for a multi-electron source according to claim 1, wherein the cold cathode device is a surface conduction electron-emitting device. 9. The driving device for a multi-electron source according to claim 1, wherein said cold cathode device is an FE-type emission device. 10. The driving device for a multi-electron source according to claim 1, wherein said cold cathode device is an MIM type emission device. 11. The apparatus according to claim 11, wherein the predetermined period in the waveform generating unit is shorter than a period obtained by dividing a period in which one row wiring is selected by the scanning unit by the number of display gradations of each color. 4. The driving device for a multi-electron source according to 3. 12. The first voltage level in the waveform generating means is set so that a parasitic capacitance existing in one column-direction wiring can be charged to a voltage for driving the cold cathode element in the predetermined period. The method of claim 11, wherein
4. The driving device for a multi-electron source according to claim 1. 13. A driving method for driving a multi-electron source in which a plurality of cold cathode devices are arranged in a matrix using a plurality of row wirings and a plurality of column wirings, wherein the plurality of cold cathode elements are driven by the plurality of row direction wirings. A scanning step of sequentially selecting the row-direction wirings, and a driving signal to be applied to each of the plurality of column-direction wirings in synchronization with the selection of the row-direction wirings in the scanning step. And applying a drive signal to the column wiring by increasing the height of the column wiring. 14. The multi-electron source according to claim 13, wherein in the driving signal applying step, a leading portion of the driving signal is detected based on a switching timing of selection of a row wiring in the scanning step. Drive method. 15. The driving signal applying step has a first voltage level for a predetermined period from a switching timing of selection of a row wiring in the scanning step, and a second voltage level lower than the first voltage level in another period. A waveform generation step of generating a reference signal having a voltage level of: a pulse width modulation step of generating and outputting a pulse signal obtained by pulse width modulation of a video signal in synchronization with selection of a row direction wiring in the scanning step. 14. An applying step of applying a signal for driving the column wiring based on a voltage signal obtained by synthesizing the reference signal and the pulse signal.
3. The method for driving a multi electron source according to claim 1. 16. The method according to claim 15, wherein the applying step outputs a current value according to the voltage signal. 17. The driving signal applying step has a first voltage level for a predetermined period from a switching timing of selection of a row wiring in the scanning step, and a second voltage level lower than the first voltage level in another period. A waveform generation step of generating a reference signal having a voltage level of; and an amplitude modulation step of generating and outputting an amplitude-modulated signal obtained by amplitude-modulating the video signal in synchronization with selection of a row-direction wiring in the scanning step. The method according to claim 13, further comprising: a current source having a current value based on the reference signal and the pulse signal, the current source outputting a current for driving the column wiring. . 18. The method according to claim 18, wherein the waveform generating step includes: a first voltage source for generating the first voltage level;
Selecting an output voltage of one of the second voltage sources that generates the voltage level of the first voltage source for a predetermined period from the switching timing of the row wiring in the scanning step. 18. The method according to claim 15, wherein the output of the second voltage source is selected during the period. 19. The waveform generating step according to claim 15, wherein the waveform data stored in advance is read from a memory, and the read waveform data is converted into a reference signal as a voltage signal. 3. The method for driving a multi-electron source according to claim 1. 20. The method according to claim 20, wherein the predetermined period in the waveform generating step is shorter than a period obtained by dividing a period in which one row wiring is selected in the scanning step by the number of display gradations of each color. 16. The driving method of the multi-electron source according to 15. 21. The first voltage level in the waveform generating step is set such that a parasitic capacitance existing in one column-direction wiring can be charged to a voltage for driving the cold cathode element in the predetermined period. 21. The method according to claim 20, wherein
3. The method for driving a multi electron source according to claim 1. 22. A multi-electron source in which a plurality of cold cathode devices are arranged in a matrix by using a plurality of row wirings and a plurality of column wirings, and a plurality of cold cathode devices are emitted from the multi-electron source at a position facing the multi-electron source. And an image forming member that forms a visible image in response to the irradiation of the electron beam, wherein the multi-electron source is driven by the driving device according to any one of claims 1 to 10. .