JPH11161223A - Electron source driving device and method, image display device using the electron source and driving method thereof - Google Patents

Abstract

(57) [Problem] To reduce the amount of invalid current flowing through a non-driving element,
Reactive power when driving the electron source is reduced. When a plurality of cold-cathode elements drive an electron source wired on a matrix by a plurality of row-direction wirings and a plurality of column-direction wirings, a correction amount calculation circuit (128) calculates image data of a line to be displayed. The application time of the predetermined voltage is determined based on When displaying the display line, the scanning signal generation circuit 129 applies the drive voltage −Vth to the row direction wiring corresponding to the line, and the modulation signal voltage conversion circuit 127 applies the display line to each of the plurality of column direction wirings. A modulation signal having a peak value + Vth based on the image data is applied. At this time, the scanning signal generation circuit 129 applies a voltage of + Vth to the unselected row direction wirings during the application time determined by the correction amount calculation circuit 128.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source driving apparatus and method in which a plurality of electron beam sources constituted by cold cathode devices are arranged on a two-dimensional plane, and an image display using the electron source. The present invention relates to an apparatus and a driving method thereof.

[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.

[0003] As a surface conduction type emission element, for example,
M. I. Elinson, Radio Eng. Ele
ctron Phys. , 10, 1290, (196
5) and other examples described later are known.

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 an O2 thin film, those using an Au thin film [G. Dittmer: "Thin Solid Fi
lms ", 9,317 (1972)] and In2O3 /
According to SnO2 thin film [M. Hartwell an
d C.I. G. FIG. Fonstad: "IEEE Tran
s. ED Conf. , 519 (1975)] and those using carbon thin films [Hisashi Araki et al .: Vacuum, Vol. 26,
No. 1, 22 (1983)].

[0005] As a typical example of the element structure 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 a schematic one, and the position and shape of the actual electron emitting portion are faithfully represented. Not necessarily.

[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 is to form an electron emission portion by energization. For example, a constant DC voltage is applied to both ends of the conductive thin film 3004 or a DC voltage is increased at a very slow rate of, for example, about 1 V / min. When a voltage is applied and current is applied, the conductive thin film 3004 is locally broken, deformed, or deteriorated, and the electron emitting portion 3005 in an electrically high resistance state
Is to form 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 30
When an appropriate voltage is applied to the element 04, electrons are emitted in the vicinity of 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, "Physicalpr
operations of thin-film figure
ld emissioncathodes 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 configuration of the FE type, FIG.
There is also an example in which an emitter and a gate electrode are arranged on a substrate almost in parallel with the plane of the substrate, instead of the laminated structure shown in FIG.

As an example of the MIM type, for example,
C. A. Mead, “Operation of tun
nel-emission Devices, J. et al. Ap
pl. Phys. , 32, 646 (1961). FIG. 19 shows a typical example of an MIM type device configuration.
Shown in The figure is a sectional view, in which 3020 is a substrate, 3021 is a lower electrode made of metal, 3022 is a thin insulating layer having a thickness of about 100 Å, 3023
Is an upper electrode made of a metal having a thickness of about 80 to 300 angstroms. In the MIM type, the upper electrode 3023
By applying an appropriate voltage between the upper electrode 3023 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 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 applications of the surface conduction electron-emitting device, for example, image forming apparatuses such as image display apparatuses and image recording apparatuses, charged beam sources, and the like have been studied.

Particularly, as an application to an image display device, 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. Meye
r: "Recent Development onM
microtips Display at LETI ",
Tech. Digest of 4th Int. V
acuum Microele-tronics C
onf. , Nagahama, pp .; 6-9 (199
1)].

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. 20, 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. Hereinafter, the signal applied to the row direction wiring is referred to as a scanning signal, and the signal applied to the column direction wiring is referred to as a modulation signal.

As described above, in driving the multi-electron beam source, it is possible to express the gradation of an image by changing the time width during which the electron beam is output.
That is, by changing the length of time during which the drive voltage Ve is applied, the length of time during which the electron beam is output can be changed, and multi-tone image display can be performed. The multi-electron beam source has, for example, a plurality of cold cathode devices arranged in a matrix as shown in FIG. 22, and scan signals by a pulse width modulation driving method as shown in FIG.
A modulation signal is applied.

As shown in FIG. 21, during period K, FIG.
The cold cathode elements in the first row (Dx1) of No. 2 are driven, and the period K +
In 1, the cold cathode elements in the second row (D × 2) are driven, and the period K
At +2, the cold cathode device (Dx3) in the third row is driven. Further, a scanning signal is applied to the row wiring and a modulation signal is applied to the column wiring. As the modulation signal, FIG.
As shown in FIG. 1, an image is displayed by applying pulses having different time widths with the same rising edge and manipulating the pulse width in accordance with an image signal. Note that a pulse having a polarity opposite to that of the above-described modulation signal is applied to the row direction wiring of the selected row, and the row direction wiring of the row not selected is grounded to the ground potential.

First, a description will be given focusing on how a current flows in the display panel during the period K. The cold cathode devices arranged in a matrix in the display panel have electric characteristics as described later in the embodiments. That is, first, the emission current Ie sharply increases when a voltage higher than a certain voltage (this is referred to as a threshold voltage Vth) is applied to the element, while the emission current Ie decreases when the voltage is lower than the threshold voltage Vth. Is hardly detected. That is, regarding the emission current Ie,
This is a nonlinear element having a clear threshold voltage Vth. Second, since the emission current Ie changes depending on the voltage Vf applied to the element, the magnitude of the emission current Ie can be controlled by the voltage Vf. Third, since the response speed of the current Ie emitted from the element to the voltage Vf applied to the element is high, the voltage Vf
The amount of charge of electrons emitted from the element can be controlled by the length of time during which f is applied. Fourth, when a voltage equal to or higher than the threshold voltage Vth is applied to the element, the element current If rapidly increases, while the element current flowing at the threshold voltage is extremely small.

In particular, due to the fourth characteristic, as shown in FIG. 22, most of the current flowing into the panel from the column wiring flows into the cold-cathode element of the selected row. The current flowing through one cold-cathode device in the non-selected row is very small as compared with the device current flowing through the selected cold-cathode device. In FIG. 22, the size (length) of the arrow indicates the amount of current flowing through the element.

However, when the number of elements is large, the small non-selection current becomes about the same as the current flowing through the selected element as a whole. In FIG. 22, the ratio of Ifr and Ifn is actually the same order. Ifr
Is a current necessary for obtaining the discharge current Ie as described later, while Ifn is an invalid current that does not contribute to the emission current Ie at all. Conventionally, there is a problem that power is consumed inactively due to the reactive current Ifn.

The present invention has been made in view of the above problems, and has been described in connection with an electron-emitting device comprising a cold cathode device.
When driving a plurality of electron beam sources arranged on a two-dimensional plane, an object of the present invention is to reduce the amount of invalid current flowing through a non-driving element and reduce the reactive power when driving the electron beam source. .

[0030]

Means for Solving the Problems An electron source driving apparatus according to one aspect of the present invention for achieving the above object has the following configuration. That is, a driving device for an electron source in which a plurality of cold cathode elements are wired in a matrix by a plurality of row-direction wirings and a plurality of column-direction wirings, and a non-driving voltage based on image data of a line to be displayed. Determining means for determining an application mode; row scanning means for selecting a row-directional wiring corresponding to the line to be displayed from the plurality of row-directional wirings and applying a driving voltage to the selected row-directional wiring; A non-selected row driving unit that applies the non-driving voltage to the row direction wiring that is not selected by the row scanning unit, and the line to be displayed on each of the plurality of column direction wirings in the application mode determined by the unit. And a column direction applying means for applying a drive signal based on the image data.

[0031]

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

[First Embodiment] The first embodiment will be described below. For convenience of explanation, the structure and the manufacturing method of the display panel, the structure and the manufacturing method of the electron-emitting device, and the structure of the electric circuit will be described in this order. Proceed.

(Configuration and Manufacturing Method of Display Panel) First, the configuration and manufacturing method of a display panel of an image display device to which the present invention can be applied will be described with reference to specific examples. FIG. 1 is a perspective view of a 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.
Are formed N × M. (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 substrate 1001 of the multi-electron beam source 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.
(A), a black conductor 1010 is provided between stripes of the fluorescent material. 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.

FIG. 2 shows how to paint the three primary color phosphors.
The arrangement is not limited to the stripe arrangement shown in FIG. 2A, and may be, for example, a delta arrangement as shown in FIG. 2B or another arrangement. 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
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 and 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 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 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 embodiment of the present invention have been described above.

(Method of Manufacturing Multi-Electron Beam Source)
A method for manufacturing the multi-electron beam source used for the display panel of the 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, under the circumstances 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 case of the MIM type, it is necessary to make the thicknesses 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 many 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.

(Planar surface conduction electron-emitting device) First, the structure and manufacturing method of a plane surface conduction electron-emitting device will be described. FIG. 3 shows a plan view (a) and a cross-sectional view (b) for explaining the configuration of a planar surface conduction electron-emitting device. In the figure, 1101 is a substrate, 1102 and 1
103, a device electrode; 1104, a conductive thin film; 1105, an electron-emitting portion formed by an energization forming process;
Reference numeral 13 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 laminated on the various substrates described above. Substrate or the like can be used.

The device electrodes 1102 and 1103 provided on the substrate 1101 so as to be parallel to the substrate surface are formed of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
The material may be appropriately selected from metals such as Ag and the like, alloys of these metals, metal oxides such as In 2 O 3 —SnO 2, and semiconductors such as polysilicon. 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 by other methods (for example, printing technique). I can't wait.

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, and 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.

More specifically, it is set within the range of several Angstroms to several thousand Angstroms, and the most preferable 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 nO2, In2 O3, PbO, Sb2 O3, 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 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. 3, the layers are stacked 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. I can't wait.

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, 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 [angstrom] or less, but 300 [angstrom] or less. Is 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, 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]. Pd or PdO is used as the main material of the fine particle film, and the thickness of the fine particle film is about 100 [angstrom].
The width W was 100 [micrometers].

Next, a description will be given of a method of manufacturing a suitable flat surface conduction electron-emitting device. (A) to (d) of FIG.
Is a cross-sectional view for explaining a 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. 4A, device electrodes 1102 and 1103 are formed on a substrate 1101.

In forming, the substrate 1
After sufficiently washing 101 with a detergent, pure water and an organic solvent,
The material of the device 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.) Thereafter, the deposited electrode material is patterned by using a photolithography / etching technique, and as shown in FIG. The illustrated pair of device electrodes (1102 and 110)
Form 3).

2) Next, a conductive thin film 1104 is formed as shown in FIG.

In the formation, 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 organic metal solution is a solution of an organic metal compound containing a material of fine particles used for the conductive thin film as a main element. (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.) In addition, as a method for forming a conductive thin film made 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, or a chemical vapor deposition method may be used. Sometimes used.

3) Next, as shown in FIG. 7C, a forming power supply 1110 supplies the device electrodes 1102 and 1102 with each other.
3, an appropriate voltage is applied, and an energization forming process is performed to form the electron-emitting portion 1105.

The energization forming treatment is to energize the conductive thin film 1104 made of a fine particle film, and to appropriately break, deform, or alter a part of the conductive thin film 1104 to change into a structure suitable for emitting electrons. This is the process that causes A portion of the conductive thin film made of a 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. 5 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. Also, monitor pulses Pm for monitoring the state of formation of the electron-emitting portion 1105 are inserted at appropriate intervals between the triangular-wave pulses, and the current flowing at that time is measured by the ammeter 1.
It was measured at 111.

In the embodiment, for example, in a vacuum atmosphere of about 10 to the fifth power [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 device electrodes 1102 and 1103 becomes 1 × 10 6 [ohm], that is, the current measured by the ammeter 1111 at the time of application of the monitor pulse is 1 × 10 −7 [A When the following conditions were reached, 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. 4D, an appropriate voltage is applied between the element electrodes 1102 and 1103 from the activating power supply 1112, and the energizing activation process is performed to perform electron emission. 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 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 4th 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. 6A 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 periodically applying a rectangular wave having a constant voltage, but specifically, the voltage Vac of the rectangular wave is 14 [V],
The pulse width T3 is 1 [millisecond], and the pulse interval T4 is 10
[Milliseconds]. Note that the above-described energization conditions are preferable conditions for the surface conduction electron-emitting device of the present embodiment,
When the design of the surface conduction electron-emitting device is changed, it is desirable to appropriately change the conditions accordingly.

An anode electrode 1114 shown in FIG. 4D 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 into 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 emission current Ie is measured by the ammeter 1116 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.
When the pulse voltage starts to be applied from 112, the emission current Ie increases with time, but eventually saturates and hardly increases. 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-mentioned 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 planar surface conduction electron-emitting device shown in FIG. 4E was manufactured.

(Vertical Type Surface Conduction Emission Element) Next, another typical structure 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. 7 is a schematic cross-sectional view for explaining the basic structure of the vertical type. In FIG.
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 device 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 SiO2 is used.

Next, a method for manufacturing a vertical surface conduction electron-emitting device will be described. FIGS. 8A to 8F are cross-sectional views for explaining a manufacturing process, and the notation of each member is the same as that in FIG.

1) First, as shown in FIG. 8A, an element electrode 1203 is formed on a substrate 1201.

2) Next, as shown in FIG. 8B, an insulating layer for forming a step forming member is laminated. The insulating layer may be formed by laminating SiO2 by sputtering, for example, but other film forming methods such as vacuum deposition or printing 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. 9D, a part of the insulating layer is removed by using, for example, an etching method to expose the element electrode 1203.

5) Next, as shown in FIG. 9E, 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, the energization forming process is performed to form an electron emission portion (the same process as the flat type energization forming process described with reference to FIG. 4C). Just do it.)

7) Next, similarly to the case of the above-mentioned planar type, an activation process is performed to deposit carbon or a carbon compound in the vicinity of the electron emitting portion (the planar type energizing described with reference to FIG. 4D). The same processing as the activation processing may be performed).

As described above, a vertical surface conduction electron-emitting device shown in FIG. 8F was manufactured.

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

FIG. 9 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 them on the same scale. In addition, these characteristics are changed by changing design parameters such as the size and shape of the element. Therefore, each of the two graphs is shown in arbitrary units.

The element used for the display device has the following three characteristics regarding the emission current Ie. Primarily,
When a voltage higher than a certain voltage (hereinafter referred to as 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 is increased.
e is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie. Second, since the emission current Ie changes depending on the voltage Vf applied to the element, the magnitude of the emission current Ie can be controlled by the voltage Vf. Third, since the response speed of the current Ie emitted from the element with respect to the voltage Vf applied to the element is high, the amount of charge of electrons emitted from the element can be controlled by the length of time during which the voltage Vf is applied.

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,
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. 10 is a plan view of the multi-electron beam source used for the display panel of FIG. On the substrate, surface conduction type emission elements similar to those shown in FIG. 3 are arranged, and these elements are wired in a simple matrix by row-direction wiring electrodes 1003 and column-direction wiring electrodes 1004. An insulating layer (not shown) is formed between the row-directional wiring electrodes 1003 and the column-directional wiring electrodes 1004 where they intersect, so that electrical insulation is maintained.

FIG. 11 is a sectional view taken along the line AA ′ of FIG.
Shown in

Incidentally, 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.

(Drive Circuit for Driving Multi-Electron Beam Source) Next, a drive circuit which is a characteristic configuration of the present embodiment will be described in detail. In the present embodiment, the scanning method is line-sequential scanning. Further, by controlling the electron emission period within one horizontal scanning time (1H) by the time width of the modulation signal, the total light emission amount of the phosphor is controlled, and the gradation of the display image is expressed. A feature of the present embodiment is that when an image is displayed line by line in line-sequential scanning, a correction signal described later is applied to the row direction wiring of the non-selected row. With this correction signal, the purpose of reducing the reactive current consumed in the cold-cathode elements in the non-selected rows and reducing the power consumed in the display panel is achieved.

FIG. 12 is a diagram for explaining a driving method of the multi-electron source and the image display device in the present embodiment. In the present embodiment, an example in which the number of row-direction elements M = 1000 and the number of column-direction elements N = 3000 will be described.

In FIG. 12, reference numeral 101 denotes a row-direction wiring,
02 is a column direction wiring, and 103 is a cold cathode element. Vx1 to VxM applied to the ends of the respective wirings are voltages applied to the ends of the row direction wirings from the first row to the Mth row, respectively.
y1 to VyN represent voltages applied to the ends of the column-directional wirings from the first row to the Nth row, respectively.

Voltages Vx1 to Vx Applied to Row Direction Wiring
FIG. 13 shows a time chart of M and the voltages Vy1 to VyN applied to the column wiring. In FIG. 13, the cold cathode elements in the first row in the period K, the second row in the period K + 1, and the period K +
FIG. 2 shows an example of voltage application timing when a voltage equal to or higher than the threshold voltage Vth is applied to the third row of cold cathode elements and electrons are emitted from the cold cathode elements for each row.

In the period K, Vx1 is set to -Vth (Vth = 7 in this embodiment) in order to drive the cold cathode elements in the first row.
V is applied, and a modulation signal (peak value = + Vth) having a time width corresponding to the image signal is applied to each column wiring. Further, a correction signal (peak value + Vth), which will be described later, is applied to the row-direction wirings of the second and third rows that are non-selected rows. Note that the same correction signal is applied to the row direction wirings of the other unselected rows. The correction signal is a signal based on a correction amount created by performing a predetermined process on a modulation signal (or an image signal) applied to each column-directional wiring. The peak value is + Vth as described above, and the time width is displayed. This reflects the image signal of the row to be read.

As described above with reference to FIG. 22, in the cold-cathode devices in the non-selected rows, when a potential difference between the voltage applied to the non-selected rows and the modulation signal applied to each column-direction wiring occurs, an invalid current flows, and Consumes power. For this reason, invalid power is generated in a general driving method in which 0 V is applied to a non-selected row. On the other hand, if a correction signal is applied to a non-selected row as shown in the time chart of FIG.
Since the peak value of both the correction signal and the modulation signal is equal to Vth, there is no potential difference between them at the beginning of each period. The potential difference occurs when the correction signal falls from Vth to 0V or when the modulation signal falls from Vth to 0V. The direction of the potential difference generated in each element is related to the time width of the modulation signal applied to each column direction wiring and the length of the time width of the correction signal, and the reactive current flows according to the direction in which the potential difference occurs. become.

Assuming that the time width of the modulation signal applied to each column direction wiring is τ1 to τN and the time width of the correction signal is T, the reactive power P (T) consumed by the cold cathode elements in the non-selected rows is as follows: 1)
It can be expressed by an equation.

[0108]

(Equation 1)

In the above equation, W is the power consumed when the threshold voltage Vth is applied to one cold cathode element, and M is the number of elements in the row direction. Although a large number of cold cathode devices are arranged in the display panel, their characteristics are almost uniform.

Since the reactive power P (T) also depends on the number M of wirings in the row direction, it increases as the number of elements (row direction) in the display panel increases. Therefore, the effect of reducing the reactive power by the correction signal is greater for a display panel having a larger number of row direction elements.

To reduce the reactive power P (T), equation (1)
May be determined so that the time width T of the correction signal is as small as possible. Compared with a case where the row direction wiring of the non-selected row is set to the ground potential without applying a pulse as a correction signal, the ratio R can be expressed as the following equation (2).

[0112]

(Equation 2)

When the time width of the correction signal is determined so that the above equation (1) becomes smaller for a certain moving image data, the magnitude of the reactive power is on average about 48% of the conventional case. . As a whole, since the reactive power was reduced, it was possible to drive the motor without consuming, on average, more than 10% of the power consumption in the conventional case.

The ratio between the reactive power consumed in the non-selected rows and the effective power consumed in the cold cathode elements in the selected row increases as the number of cold cathode elements in the display panel increases, that is, as the definition increases. . Therefore, the display panel of this embodiment (M = 1
(N, 3,000) can be expected to save more power.

(Method of Creating Correction Signal) Next, a method of creating the correction signal described in the first embodiment and a specific driving method will be described. As the time width T of the correction signal, a value that minimizes Expression (1) is optimal. However, calculating the time width T that minimizes the expression (1) requires a large number of repetitive calculations. Therefore, the calculation in the correction amount calculation circuit described below is simplified, and an appropriate correction amount, that is, a time width T of the correction signal is determined in real time.

FIG. 14 is a diagram for explaining the image display device of the present embodiment. The signal flow will be described with reference to FIG.

First, a video signal such as an NTSC signal is input to the decoder 121. Although not shown here, the decoder 121 includes a video intermediate frequency circuit, a video detection circuit, a synchronization separation circuit, an A / D conversion circuit, and the like.
It outputs a synchronization signal Sync and digital image signals R, G, and B. Here, the synchronization signal Sync includes a vertical synchronization signal and a horizontal synchronization signal, and R, G, and B include luminance data for each of red, green, and blue.

The timing control circuit 123 generates a timing signal for adjusting the operation timing of each section based on the synchronization signal supplied from the data. The flow of the timing signal from the timing control circuit 123 to each unit is indicated by a dotted arrow in FIG.

The data arrangement conversion circuit 122 arranges the luminance data (R, G, B) of the three primary colors supplied from the decoder in accordance with the pixel arrangement of the display panel, and outputs it as a serial digital signal Data. Data array conversion circuit 1
The digital image signal Data output from 22 is sequentially stored in the S / P conversion circuit 124 and the correction amount calculation circuit 128 based on the timing signal supplied from the timing control circuit.

The correction amount corresponding to the time width of the correction signal is 1
The correction amount is calculated by the correction amount calculation circuit 128 every horizontal period. FIG.
5 is a block diagram showing a detailed configuration of the correction amount calculation circuit 128. As shown in FIG. 15, the correction amount calculation circuit 128
Are average value calculation circuit 201, median value detection circuit 202, S
/ P conversion circuit 203, one-line memory 204, CPU2
05.

The calculation procedure of the correction amount by the correction amount calculation circuit 128 will be described with reference to the flowchart of FIG.

The digital image signal Data transferred from the data array conversion circuit 122 is converted into a correction amount calculation circuit 128
, Average value calculation circuit 201, median value detection circuit 202, S
The signal is input to the / P conversion circuit 203 in parallel.

The S / P conversion circuit 203 accumulates the digital signal Data transferred serially and transfers the data for one horizontal line to the one-line memory 204 when the transfer of the digital signal for one horizontal period is completed. (Steps S100, S110).

The average value calculation circuit 201 is a circuit for calculating the average value of the digital image signal within one horizontal period. In the average value calculation circuit 201, Data is added as Data is serially transferred. Then, the digital image signal Data for one horizontal period is transferred, but the average value is calculated and output almost simultaneously with the end of the transfer (step S101).

The median value detection circuit 202 is a circuit for detecting the median value of a digital image signal within one horizontal period. Since the configuration of such a circuit for detecting the median value is obvious to those skilled in the art, the circuit configuration is not shown, but a multiplexer and 256 counters (however, 8-bit image data having a value of 0 to 255 are used). Case) and a comparator. At about the same time when the transfer of the digital image signal Data for one horizontal period ends, the median value of the digital image signal Data is detected (step S10).
2). Note that, in the present embodiment, the median value of the image signal Data indicates the most frequent value in the distribution map when the distribution map of the image signal Data in one horizontal period is created. I do.

When the average value and the median value are calculated by the average value calculation circuit 201 and the median value detection circuit 202 as described above, the CPU 205 calculates these values and the digital image signal Data stored in the one-line memory 204. And read. Then, the calculation of the above equation (1) is performed for each of the average value and the median value (step S103), and the smaller value of the equation (1) is selected as the correction amount (step S104). The correction amount thus selected is transferred to the scanning signal generation circuit 129 (step S10).
5).

In FIG. 14, scanning signal generation circuit 129
Is a circuit for generating a scanning signal for sequentially scanning a multi-electron beam source incorporated in the display panel in accordance with the timing of displaying an image. Specifically, among the terminals Dx1 to DxM of the display panel, the selection signal Vs is applied to the selected row direction wiring, and the correction amount calculated by the correction operation circuit 128 is applied to the other non-selected row direction wirings. And outputs a correction signal Vns having a time width corresponding to.

On the other hand, the output of the one-line memory 125 is connected to the input of the pulse width modulation circuit 126. The pulse width modulation circuit 126 has modulation control signals D1 to D having pulse widths corresponding to data supplied from the one-line memory 125.
N is output. The pulse width modulation circuit 126 mainly includes a counter and a latch, counts in accordance with the timing supplied from the timing control circuit, and has a pulse width modulation having a time width corresponding to the digital video signal supplied from the one-line memory. It is a circuit that converts it into a signal.

In the modulation signal voltage conversion circuit 127, the pulse width modulation signals D1 to D1 supplied from the pulse width modulation circuit 126 are output.
This is a circuit for converting DN to a voltage level optimal for driving the display panel. The display panel 130 has an Hv terminal as shown in the figure, and a high voltage Va is applied.

FIG. 1 shows a time chart of the voltage applied to each row-direction wiring and column-direction wiring of the display panel.
It looks like 3. The selection signal, correction signal and modulation signal are shown in FIG.
As shown in FIG. 3, when viewed within one horizontal scanning period, all of the waveforms become rectangular waves whose rising edges are synchronized. The selection signal is a rectangular wave of a peak value -Vth having a time width of about one horizontal scanning period, and the modulation signal applied to each column direction wiring has a pulse width corresponding to the image data of the displayed row. ,
This is a rectangular wave having a peak value + Vth. The correction signal applied to the row direction wiring of the non-selected row, which is a characteristic signal of the present embodiment, corresponds to the correction amount created by performing the above-described calculation on the image signal of the displayed row. Is a rectangular wave having a peak value + Vth having the specified time width T.

When the display panel is driven with such a circuit configuration, the reactive power is reduced as described above, and the power consumed by the display panel is on average 10 times less than when driven by the conventional drive circuit. % Could be reduced. The average value of the amount of power that can be reduced naturally depends on the image to be displayed, not to mention the design specifications of the display panel. However, the present results were obtained as a result of the inventors measuring the power consumption of the present image display device for some images. Therefore, when the same measurement is performed for different image signals, the value that can be reduced may slightly change, but the power is saved more than when the correction signal is not applied as in the conventional example described in the problem. The present inventors have confirmed that this is possible.

As described above, according to the first and second embodiments, when driving the multi-electron source and the image display device to which the multi-electron source is applied, the cold cathode devices arranged in the non-selected rows are used. The consumed reactive power can be saved. As a result, it is possible to reduce the power consumption of the multi-electron source driving device and the entire image display device. In the above embodiment, since the gradation expression is performed by the pulse width modulation, the correction amount calculation circuit 128 sets an appropriate time width of the correction signal applied to the non-selected row, but is not limited thereto. For example, it is apparent that the present invention can be applied to a case where a gray scale is expressed by a voltage value applied to an electron-emitting device. In this case, the correction amount calculation circuit 128
An appropriate voltage value is set as a correction signal based on the image data for the line.

(Application Example of Display Panel According to the Present Embodiment) FIG. 23 shows a display panel using the surface conduction electron-emitting device described above as an electron beam source, and various image information sources such as television broadcasting. FIG. 3 is a diagram illustrating an example of a multi-function display device configured to display image information provided by the multi-function display device. In the figure, 210
0 is a display panel, 2101 is a display panel driving circuit, 2102 is a display controller,
2103 is a multiplexer, 2104 is a decoder, 21
05 is an input / output interface circuit, 2106 is a CP
U and 2107 are image generation circuits, 2108 and 2109
And 2110 are image memory interface circuits, 2
111 is an image input interface circuit, 2112 and 2113 are TV signal receiving circuits, and 2114 is an input unit.

When the present display device receives a signal containing both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Descriptions of circuits, speakers, and the like relating to reception, separation, reproduction, processing, storage, and the like of audio information that are not directly related to the features of the invention are omitted. Hereinafter, the function of each unit will be described along the flow of the image signal.

First, the TV signal receiving circuit 2113 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication.
The type of TV signal to be received is not particularly limited,
For example, various systems such as the NTSC system, the PAL system, and the SECAM system may be used. A TV signal (for example, a so-called high-definition TV such as the MUSE system) composed of a larger number of scanning lines 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. As with the TV signal receiving circuit 2113, 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.

The image input interface circuit 21
Reference numeral 11 denotes a circuit for receiving an image signal supplied from an image input device such as a TV camera or an image reading scanner.
Is output to

The image memory interface circuit 2
110 is a video tape recorder (hereinafter abbreviated as VTR)
Is a circuit for capturing the image signal stored in the decoder 2104. The captured image signal is output to the decoder 2104.

The image memory interface circuit 2
Reference numeral 109 denotes a circuit for capturing an image signal stored in the video disk, and the captured image signal is output to the decoder 2104.

The image memory interface circuit 2
Reference numeral 108 denotes a circuit for taking in an image signal from a device that stores still image data, such as a so-called still image disk.
04 is output.

The input / output interface circuit 210
Reference numeral 5 denotes 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 is provided with image data, character / graphic information input from the outside via the input / output interface circuit 2105, or a CPU.
A circuit for generating display image data based on the image data and character / graphic information output from 2106.
The circuit includes a rewritable memory for storing, for example, 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 this circuit is output to the decoder 2104, but may be input / output to an external computer network or a printer via the input / output interface circuit 2105 in some cases.

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 multiplexer 2103, and image signals to be displayed on the display panel are appropriately selected or combined. In this case, a control signal is generated for the display panel controller 2102 in accordance with the image signal to be displayed, and the display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines on one screen, and the like are displayed. The operation of the device is appropriately controlled.

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 access the image data or character / graphic information. Enter graphic information.

The CPU 2106 may, of course, be involved in work for other purposes. For example, it may directly relate to a function of generating and processing information, such as a personal computer or a word processor.

Alternatively, the computer may be connected to an external computer network via the input / output interface circuit 2105 as described above, and operations such as numerical calculation may be performed in cooperation with an external device.

The input unit 2114 is connected to the CPU 21.
06 is for the user to input commands, programs, data, and the like. For example, in addition to a keyboard and a mouse, a joystick, a barcode reader,
Various input devices such as a voice recognition device can be used.

Also, the decoder 2104 has the
And 2113 are circuits for inversely converting various image signals inputted from 2113 into three primary color signals or luminance signals and I and Q signals. 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 a television signal that requires an image memory when performing inverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of a still image, or enables image processing and editing including image thinning, interpolation, enlargement, reduction, and synthesis in cooperation with the image generation circuit 2107 and the CPU 2106. This is because there is an advantage that it can be easily performed.

The multiplexer 2103 is connected to the C
A display image is appropriately selected based on a control signal input from the PU 2106. 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 2
Reference numeral 102 denotes a circuit for controlling the operation of the drive 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, for example, a signal for controlling an operation sequence of a driving power supply (not shown) for the display panel is output to the driving circuit 2101. Also,
A signal for controlling, for example, a screen display frequency and a scanning method (for example, interlaced or non-interlaced) 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 brightness, contrast, color tone, and sharpness of a display image may be output to the drive circuit 2101.

The drive circuit 2101 is a circuit for generating a drive signal to be applied to the display panel 2100. The drive circuit 2101 is a circuit for generating an image signal input from the multiplexer 2103 and the display panel controller 21.
02 operates based on a control signal input from the control unit 02.

The function of each section has been described above. With the configuration illustrated in FIG. 23, the display device according to the present embodiment can display image information input from various image information sources on the display panel 2.
100 can be displayed. That is, various image signals including television broadcasting are transmitted to the decoder 21.
After the inverse conversion at 04, the multiplexer 2103
And is input to the driving circuit 2101 as appropriate. 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 drive circuit 2101 controls the display panel 2 based on the image signal and the control signal.
100 is applied with a drive signal. Accordingly, an image is displayed on display panel 2100. These series of operations are totally controlled by the CPU 2106.

Further, in the present display device, the image memory built in the decoder 2104, the image generation circuit 21
07 and the CPU 2106 involve not only displaying a selected one of a plurality of pieces of image information but also enlarging, reducing, rotating, moving, edge emphasizing, thinning out, and interpolating the displayed image information. , Color conversion,
It is also possible to perform image processing such as image aspect ratio conversion and the like, and image editing such as combining, erasing, connecting, exchanging, and fitting. Although not specifically mentioned 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 present display device is a television broadcast display device, a video conference terminal device, an image editing device that handles still and moving images, a computer terminal device, an office terminal device including a word processor,
It can be equipped with the functions of a game machine etc. by one unit, and has a very wide application range for industrial or consumer use.

FIG. 23 shows only an example of the configuration of a display device using a display panel using a surface conduction electron-emitting device as an electron beam source, and the present invention is not limited to this. Needless to say. For example, FIG.
Circuits related to functions unnecessary for the purpose of use among the three components 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 beam source can be easily made thin, so that the depth of the entire display device can be reduced. In addition, the display panel using surface conduction electron-emitting devices as the electron beam source can easily enlarge the screen, and has high brightness and excellent viewing angle characteristics. It is possible to display well.

[0160]

As described above, according to the present invention,
When driving an electron source in which a plurality of electron-emitting devices constituted by cold cathode devices are arranged on a two-dimensional plane, the amount of invalid current flowing through the non-driving device is reduced, Reactive power is reduced.

[0161]

[Brief description of the drawings]

FIG. 1 is a perspective view of an image display apparatus according to an embodiment of the present invention, in which a part of a display panel is cut away.

FIG. 2 is a plan view illustrating a phosphor array of a face plate of the display panel.

FIG. 3A is a plan view of a planar type surface conduction electron-emitting device used in the embodiment, and FIG. 3B is a cross-sectional view thereof.

FIG. 4 is a cross-sectional view illustrating a manufacturing process of the planar surface-conduction emission type electron-emitting device.

FIG. 5 is a diagram showing an applied voltage waveform at the time of energization forming processing.

FIG. 6A is a diagram showing an applied voltage waveform at the time of an energization activation process, and FIG. 6B is a diagram showing a change in a discharge current Ie.

FIG. 7 is a sectional view of a vertical surface conduction electron-emitting device used in the embodiment.

FIG. 8 is a sectional view showing a manufacturing process of a vertical surface conduction electron-emitting device.

FIG. 9 is a view showing typical characteristics of the surface conduction electron-emitting device used in the embodiment.

FIG. 10 is a plan view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 11 is a partial cross-sectional view of a substrate of the multi-electron beam source used in the embodiment.

FIG. 12 is a diagram showing a matrix wiring of an electron source in the display device used in the embodiment.

FIG. 13 is a timing chart of a drive signal used in the embodiment.

FIG. 14 is a block diagram illustrating a configuration of a drive circuit used in the embodiment.

FIG. 15 is a block diagram illustrating a configuration of a correction amount calculation circuit used in the embodiment.

FIG. 16 is a flowchart of a correction amount calculation used in the embodiment.

FIG. 17 is a view showing an example of a conventionally known surface conduction electron-emitting device.

FIG. 18 is a diagram showing an example of a conventionally known FE.

FIG. 19 is a diagram showing an example of a conventionally known MIM type.

FIG. 20 is a diagram illustrating a wiring method of an electron-emitting device in which a problem that the inventors have attempted has occurred.

FIG. 21 is a timing chart for explaining a conventional pulse width modulation driving method.

FIG. 22 is a diagram for explaining the problem of the present invention.

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

Claims (15)

[Claims] 1. An electron source driving device in which a plurality of cold cathode devices are wired in a matrix by a plurality of row-direction wirings and a plurality of column-direction wirings, wherein the driving device operates based on image data of a line to be displayed. Determining means for determining a driving voltage application form; row scanning means for selecting a row wiring corresponding to the line to be displayed from the plurality of row wirings and applying a driving voltage to the selected row wiring. And a display unit configured to apply the non-driving voltage to the row-direction wiring not selected by the row scanning unit in the application mode determined by the determination unit, and to display the display on each of the plurality of column-direction wirings. And a column direction applying means for applying a drive signal based on image data of a line to be driven. 2. The electron source driving device according to claim 1, wherein each of the plurality of row direction wirings corresponds to one horizontal scan of an image. 3. The column direction applying means generates a modulation signal having a time width corresponding to the image data of the line to be displayed and a predetermined peak value, and uses the modulation signal as a drive signal for the plurality of column direction wirings. 2. The electron source driving device according to claim 1, wherein each of the non-driving voltages is applied, and the determining unit determines an application time of the non-driving voltage as an application form. 4. The non-driving voltage has substantially the same polarity and crest value as the modulation signal.
3. The electron source driving device according to claim 1. 5. The determination means determines the application time such that the sum of the absolute value of the difference between the time width of the modulation signal applied to each column direction wiring and the application time is minimized. The electron source driving device according to claim 3, wherein 6. The electron source driving device according to claim 3, wherein the determination unit determines an average value of a time width of the modulation signal applied to each column direction wiring as the application time. 7. The electronic device according to claim 3, wherein the determination unit determines, as the application time, a most frequent time width among the modulation signals applied to each column direction wiring. Source drive. 8. The electron source according to claim 1, wherein the determination unit calculates an average value of the image data of the line to be displayed, and determines the application mode based on the average value. Drive. 9. The method according to claim 1, wherein the determining unit extracts a value having the highest frequency from the image data of the line to be displayed, and determines the application mode based on the extracted value. 2. The electron source driving device according to 1. 10. The electron source driving device according to claim 1, wherein the application form is a voltage value of the non-driving voltage. 11. The electron source driving device according to claim 1, wherein said cold cathode device is a surface conduction electron-emitting device. 12. A method for driving an electron source in which a plurality of cold cathode devices are wired in a matrix by a plurality of row-direction wirings and a plurality of column-direction wirings, wherein a non-cold cathode device is driven based on image data of a line to be displayed. A determining step of determining a driving voltage application mode, and a row scanning step of selecting a row direction wiring corresponding to the line to be displayed from the plurality of row direction wirings and applying a driving voltage to the selected row direction wiring; A non-selected row driving step of applying the non-driving voltage to the row direction wiring not selected in the row scanning step in the application mode determined in the determining step, and the display in each of the plurality of column direction wirings. Applying a drive signal based on image data of a line to be applied in a column direction. 13. A non-driving voltage application mode based on an electron source in which a plurality of cold cathode devices are wired in a matrix by a plurality of row-direction wirings and a plurality of column-direction wirings, and image data of a line to be displayed. Determining means for selecting, a row-directional wiring corresponding to the line to be displayed from the plurality of row-directional wirings, and a row scanning means for applying a drive voltage to the selected row-directional wiring; In the determined application mode, the non-selected row driving means for applying the non-driving voltage to the row direction wiring not selected by the row scanning means and the image of the line to be displayed on each of the plurality of column direction wirings A column direction applying unit that applies a driving signal based on data, and a driving voltage applied by the row scanning unit and a driving signal applied by the column direction applying unit.
An image display device comprising: a light emitting unit that emits light by electrons emitted from the electron source. 14. The image display device according to claim 13, wherein said light emitting means is a phosphor. 15. A plurality of cold cathode devices, an electron source wired in a matrix by a plurality of row wirings and a plurality of column wirings, a driving voltage applied to the row wirings and a voltage applied to the column wirings. A light emitting unit that emits light by the electrons emitted from the electron source in response to a driving signal, wherein a non-driving voltage application mode is determined based on image data of a line to be displayed. Determining a row-directional wiring corresponding to the line to be displayed from the plurality of row-directional wirings, and applying the driving voltage to the selected row-directional wiring; A non-selected row driving step of applying the non-driving voltage to the row direction wiring not selected in the row scanning step, and a method of applying the line to be displayed to each of the plurality of column direction wirings. A column direction application step of applying a drive signal based on image data.