JPH0917359A - Electron source, display panel and image forming device and manufacture of these - Google Patents

Abstract

PURPOSE: To reduce a failure occurrence rate in a connecting point, and inexpensively enable manufacture by connecting upper wiring and one electrode of an electron emitting element to each other by a recessed part in the direction in parallel to a base board surface of an insulating layer on the electron emitting element. CONSTITUTION: A dielectric thin film composed of a metallic material is formed on an excellently cleaned base board 1, and fine processing is performing on this pattern by a photolithographic method, and element electrodes 2 and 3 are formed, and a pattern of a lower wiring electrode 5 is formed of conductive paste by a printing method so as to contact with a part of the element electrode 3, and it is baked. A belt-like pattern having a recessed part 7 in a position of the element electrode 2 is printed and baked on it by insulating paste, and an insulator 6 is formed. Upper wiring 8 electrically continuing with the element electrode 2 by the recessed part 7 is printed, baked and formed on this by conductive paste. After a thin film composed of a particulate electron emitting material is formed over the whole surface on this, patterning is formed by a photolithographic method, and a thin film 4 is formed, and a crack of an electron emitting part 9 is formed by foaming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, an electron source mainly using a surface conduction electron-emitting device, a display panel, an image forming apparatus, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a simple matrix liquid crystal display device (LC) has been used as a display technique for realizing a flat display device.
D), thin film transistor liquid crystal display device (TFT / LC
D), plasma display (PDP), low-speed electron beam fluorescent display (VFD), and other flat panel display technologies.

As an example of these display technologies, a light emitting element that emits a phosphor using an electron source and a flat panel display using the same will be described below.

[0004] Conventionally, as an element which can emit electrons with a simple structure, a report by Elinson (MI Elinson, Radio
Eng. Electron Phys., 10 (1965)).

This utilizes a phenomenon in which electron emission occurs when a current is passed through a thin film having a small area formed on a substrate in parallel with the film surface.

As such a surface conduction electron-emitting device, one using a SnO ₂ thin film described in the above-mentioned Erinson report, one using an Au thin film (G. Dittmer, Thin Sol
id Films, 9, 317 (1972)), In ₂ O ₃ / SnO ₂ thin film (M. Hartwell and CG Fonstad, IEEE Tran
s. ED Conf., 519 (1975)), by a carbon thin film (Araki et al., Vacuum, Vol. 26, No. 1, p. 22 (198).
3)) etc. have been reported. FIG. 6 shows the Hartwell device structure as a typical device structure of these surface conduction electron-emitting devices. In the figure, 31 is a substrate, 32 is a thin film for forming an electron emitting portion, which is made of an H-shaped metal oxide or the like formed by sputtering, and is subjected to a process called forming (or energization forming). Is formed.

The term "forming" used herein means that a voltage is applied to both ends of the electron-emitting-portion forming thin film 32 to locally destroy, deform or alter the electron-emitting-portion forming thin film, thereby providing an electrically high resistance. This is to form the electron emission portion 33 in such a state. In some cases, the electron emitting portion 33 has a crack in a part of the electron emitting portion forming thin film, and electrons are emitted from the vicinity of the crack.

[0008] The present inventors have also proposed USP506688.
3 discloses a novel surface conduction electron-emitting device in which fine particles for emitting electrons are dispersedly arranged between device electrodes. According to the method disclosed therein, the electron emission position can be controlled more precisely, and the electron emission devices can be arranged more precisely, as compared with the case of manufacturing the conventional surface conduction electron emission device. FIG. 7 shows a typical device configuration of the surface conduction electron-emitting device thus manufactured. In this figure, 41 is an insulating substrate, 42 and 43 are element electrodes for obtaining electrical connection, 44 is a thin film made of dispersed fine particle electron emitting materials, and 45 is an electron emitting portion.

In such a surface conduction electron-emitting device, the electrode interval between the pair of electrodes 42 and 43 is
0.01 μm to 100 μm, and the sheet resistance of the electron emitting portion of the thin film 44 is preferably 1 × 10 ³ Ω / □ to 1 × 10 ⁹ Ω / □.

When the surface conduction electron-emitting device described above is used as an electron-emitting device, it must be placed in a vacuum container for flying an electron beam. A face plate is provided almost vertically above the device in a vacuum container, a phosphor is arranged, a voltage is applied between electrodes, and the phosphor is irradiated with the electron beam obtained from the electron emission section. It can be used as a light-emitting element or a flat-panel display by causing the body to emit light.

[0011]

However, when an image forming apparatus is manufactured using such a surface conduction electron-emitting device, there are the following problems.

In order to display pixels, the surface conduction electron-emitting device must be miniaturized and a large number of devices must be arranged two-dimensionally. A large number of wirings are required to individually control a large number of elements. Therefore, a structure in which wirings of two or more systems are stacked via an insulating layer and individual elements are connected is used.

As a manufacturing method for realizing such a structure, conventionally, a thin film formation and a photolithography method, which are widely used in the manufacture of semiconductor integrated circuits, have been used. Since the photolithography method enables accurate microfabrication, the electrode wiring provided on the insulating layer and the element are often connected to each other by a fine contact hole provided in the insulating layer.

However, the photolithography method is high in cost, and when the area is large as in the image forming apparatus, the manufacturing cost is further increased, which is disadvantageous in commercialization.

Therefore, it is required to manufacture by a low cost method such as a printing method. In that case, the step of forming a contact hole in an insulating layer is difficult as compared with the photolithography method in terms of fine processing. However, a great deal of effort has been required to improve the product yield in contact holes.

Therefore, according to the present invention, a method of manufacturing an electron source, a display panel and an image forming apparatus at a low cost by reducing the occurrence rate of defects at connection points even when an insulating layer is formed by a printing method, and the method thereof. An object of the present invention is to provide a highly reliable electron source, a display panel and an image forming apparatus manufactured by such a method.

[0017]

According to the present invention, lower wirings and upper wirings are formed in a matrix on a substrate through a strip-shaped interlayer insulating layer, and device electrode pairs are formed on the substrate at the intersections of the upper and lower wirings. In the electron source in which the electron-emitting device is arranged, the upper wiring is formed on the strip-shaped interlayer insulating layer along the insulating layer, and the insulating layer is parallel to the substrate surface on the electron-emitting device. An electron source having a concave portion in any direction, and the upper wiring and one element electrode of the electron-emitting device are connected in the concave portion, and the electron source and the substrate facing each other. A display panel in which a substrate on which phosphors are arranged overlaps with each other through an envelope, and an internal space formed by these substrates and the envelope is evacuated, and at least a drive circuit is connected to the display panel. Provided is an image forming apparatus.

The present invention further includes 1) a step of forming an electron-emitting device having a device electrode pair on a substrate, and 2) forming a lower wiring connected to one electrode of the device electrode pair on the substrate. And 3) a step of forming an upper wiring connected to the other electrode of the element electrode pair on the lower wiring so as to form a matrix with the lower wiring via a strip-shaped interlayer insulating layer. In the method for manufacturing an electron source, the strip-shaped interlayer insulating layer is formed in the same direction as the upper wiring in the shape having a recess in a direction parallel to the substrate surface on the electron-emitting device, and the upper wiring is formed in the recess. A method of manufacturing an electron source, characterized in that the wiring is connected to one of the element electrodes of the electron-emitting device, the electron source and a substrate on which a phosphor is arranged facing the substrate via an envelope. Stacked inside, formed by both these substrates and the envelope Provided are a method of manufacturing a display panel that evacuates a space, and a method of manufacturing an image forming apparatus that connects at least a drive circuit to the display panel.

[0019]

FIG. 1 shows a schematic plan view of one embodiment of an electron source using a surface conduction electron-emitting device manufactured by the method of the present invention. In this figure, 1 is a substrate made of an insulator, 2
Reference numerals 3 and 3 are device electrodes for obtaining electrical connection, and 4 is a thin film made of a fine particle electron emitting material.

In this surface conduction electron-emitting device, the electrode spacing between the pair of electrodes 2 and 3 is several μm to several hundred μm, and the film thickness is several hundred Å to several thousand Å. It is formed by patterning the metal thin film formed by the photolithography method. Further, the film thickness of the thin film 4 is preferably in the range of several tens Å to several thousands Å, and can be appropriately set within the range. The thin film 4 is patterned and separated by the photolithographic method in the same manner as the electrode spacing. Reference numeral 5 denotes a lower wiring electrode connected to the device electrode 3, and both have a film thickness in the range of several μm to several tens of μm. Reference numeral 6 is an insulator, which is formed in a strip shape, and a recess 7 is provided at an intersection with the element electrode 2, and the element electrode 2 is exposed at that portion. Reference numeral 8 denotes an upper wiring electrode, which is connected to the device electrode 2 at the position of the recess 7. Reference numeral 9 is an extremely fine crack formed in the thin film 4 which serves as an electron emitting portion.

With the above structure as a unit, this constitutes one surface conduction electron-emitting device, and a large number of these are provided on the substrate 1 to form an electron source.

FIG. 2 shows a cross-sectional view of a display panel using the electron source having such a structure. The electron source of FIG. 1 is arranged in a vacuum container, and a face plate is provided vertically above the electron source. The face plate has a structure in which a phosphor 22 and a metal back 23 are laminated on a glass substrate 21.
Here, when a voltage is applied between the device electrodes 2 and 3, the crack-like structure formed in the thin film 4 between the device electrodes becomes the electron emitting portion 9, and the metal back 23 serves as the + side electrode, so that electrons are emitted to the phosphor. Upon irradiation, the phosphor emits light, which can be used as a light emitting element or a flat panel display device.

Further, by applying a voltage to the electron-emitting devices connected to the upper and lower wiring electrodes 5 and 8 shown in FIG. An image can be displayed by causing the fluorescent substance at the position to emit light.

The method of manufacturing the electron source of the present invention will be described below with reference to FIGS.

In FIG. 3, a conductive thin film made of a metal material is formed on the substrate 1 that has been thoroughly washed, and this pattern is finely processed by photolithography to form element electrodes 2 and 3 (FIG. 3A). ).

Next, a conductive paste is pattern-printed by a printing method to directly form a pattern of the lower wiring electrode 5 and firing is performed. These lower wiring electrodes 5 are arranged so as to contact a part of the device electrodes 3 (FIG. 3B).

An insulating paste is printed thereon and fired to form a band-shaped pattern having recesses 7, and the insulator 6 is formed.
To form The recess 7 is arranged at the position of the device electrode 2 (FIG. 3 (c)).

Furthermore, an upper wiring electrode 8 is formed by printing and firing a conductive paste on the strip-shaped insulator 7. The upper wiring electrode 8 is electrically connected to the element electrode 2 in the recess 7 (FIG. 3 (d)).

A thin film made of a fine particle electron emitting material is formed on the entire surface, and then patterned by photolithography to form a thin film 4, and a crack 9 is formed by forming (FIG. 3 (e)).

Here, as the substrate 1, quartz glass, N
Glass with low content of impurities such as a, soda lime glass, Si
A glass substrate having O ₂ laminated on the surface thereof, a ceramic substrate of alumina or the like is used.

Device electrodes 2 and 3, which face each other, lower wiring electrode
5, the material of the upper wiring electrode 8 has conductivity
Anything can be used, for example,
Ni, Cr, Au, Mo, W, Pt, Ti, Al, C
Metals such as u and Pd, their alloys, or this
Alloys of these metals, or Pd, Ag, Au, Ru
O_Two, Metal such as Pd-Ag or oxide and glass
Printed conductor composed of In _Two0_Three-SnO_TwoTransparent guidance
Appropriately selected from electric conductors and semiconductors such as polysilicon
Selected.

As a material for the insulator 6, a general glass paste can be used.

Further, as a material for forming the thin film 4 including the electron emitting portion, Pd, Pt, Ru, Ag, Au, Ti,
In, Cu, Cr, Fe, Zn, Sn, Ta, W, Pb
Metals such as PdO, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂
Oxides O _{3,; HfB 2, ZrB 2, LaB} 6, Ce
Borides of B ₆ , YB ₄ , GdB _4, etc .; TiC, ZrC, H
Carbides such as fC, TaC, SiC, WC; TiN, Zr
Examples thereof include nitrides such as N and HfN; semiconductors such as Si and Ge; carbon and the like.

The fine particle film mentioned here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state in which the fine particles are individually dispersed and arranged but also in a state in which the fine particles are adjacent to each other or overlap each other (island). (Including the shape) refers to the film.

The electron emitting portion 9 is a high-resistance crack formed in a part of the conductive thin film 4 by the forming process. The crack may have several Å to several hundred Å conductive fine particles. The conductive fine particles contain at least a part of the elements forming the conductive thin film 4. Further, the electron emitting portion 9 and the conductive thin film 4 in the vicinity thereof may contain carbon or a carbon compound.

In the energization forming, electricity is applied between the device electrodes 2 and 3 from a power source (not shown) to locally destroy, deform or alter the conductive thin film 4 to form a portion having a changed structure. . The site where the structure is locally changed is the electron emitting portion 9. FIG. 8 shows an example of the voltage waveform of energization forming.

The voltage waveform is preferably a pulse shape, and the voltage pulse having a constant pulse peak value is continuously applied (FIG. 8A) and the voltage pulse is applied while increasing the pulse peak value (FIG. 8A). 8 (b)). First,
A case where the pulse peak value is a constant voltage (FIG. 8A) will be described.

In FIG. 8A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, and T1 is 1 μsec to 10 μs.
Millisecond, T2 is set to 10 μsec to 100 msec, the peak value of the triangular wave (peak voltage during energization forming) is appropriately selected according to the form of the surface conduction electron-emitting device, and a suitable vacuum degree, for example, 1 × 10. ^In a vacuum atmosphere of about ^-5 Torr,
Apply for several seconds to several tens of minutes. The waveform applied between the electrodes of the element is not limited to the triangular wave, and a desired waveform such as a rectangular wave may be used.

T1 and T2 in FIG.
Similar to the case of (a), the peak value of the triangular wave (peak voltage during energization forming) is increased by, for example, about 0.1 V step and applied in an appropriate vacuum atmosphere.

In the energization forming process in this case, the conductive thin film is locally destroyed during the pulse interval T2.
With a voltage that does not deform, for example, a voltage of about 0.1 V,
The device current is measured, the resistance value is obtained, and when the resistance is 1 MΩ or more, the energization forming is completed.

Next, it is desirable to perform a process called an activation process on the element for which the energization forming has been completed.

The activation step is, for example, 10 ^-4 to 10 ^-5.
Similar to energization forming, this is a process of repeatedly applying a voltage pulse with a constant pulse peak value at a vacuum degree of about Torr. Carbon or a carbon compound derived from an organic substance existing in a vacuum is deposited on a conductive thin film. Element current I
This is a process of significantly changing the emission current Ie. The activation process is completed, for example, when the emission current Ie is saturated while measuring the device current If and the emission current Ie. Further, it is preferable that the applied voltage pulse is an operation drive voltage.

Here, carbon or carbon compound means graphite (which refers to both single crystal and polycrystal) and amorphous carbon (which refers to a mixture of amorphous carbon and polycrystal graphite), and its film. Thickness is 500
It is preferably Å or less, more preferably 300 Å or less.

The electron-emitting device thus manufactured is preferably operated and driven in an atmosphere having a vacuum degree higher than the vacuum degree in the energization forming step and the activation step. Also, in an atmosphere with a higher degree of vacuum, 80 ° C to 150 ° C
It is desirable to drive after heating.

The degree of vacuum higher than the degree of vacuum obtained by the energization forming process and activation treatment means, for example, about 10 ⁻⁶ Tor.
The degree of vacuum is equal to or higher than r, more preferably an ultrahigh vacuum system, and the degree of vacuum is such that new carbon or carbon compound is hardly deposited on the conductive thin film. By doing so, the device current If and the emission current Ie can be stabilized.

Next, the display panel and the image forming apparatus of the present invention will be described.

The electron source used for the display panel is formed by arranging a plurality of surface conduction electron-emitting devices on the substrate.

As a method of arranging the surface-conduction type electron-emitting devices, the surface-conduction type electron-emitting devices are arranged in parallel, and both ends of the individual devices are connected by a ladder arrangement (hereinafter referred to as a ladder-type arrangement electron source substrate). And a simple matrix arrangement (hereinafter referred to as a matrix-type arrangement electron source substrate) in which the X-direction wiring and the Y-direction wiring of a pair of device electrodes of the surface conduction electron-emitting device are connected, respectively. An image forming apparatus having a ladder type electron source substrate requires a control electrode (grid electrode) which is an electrode for controlling the flight of electrons from the electron-emitting device.

The structure of the electron source manufactured based on this principle will be described below with reference to FIG. In the figure, 51 is an electron source substrate, 52 is an X-direction wiring, 53 is a Y-direction wiring, 5
Reference numeral 4 is a surface conduction electron-emitting device, and 55 is a connection.

In the figure, the substrate used for the electron source substrate 51 is the above-mentioned glass substrate or the like, and its shape is appropriately set according to the application.

The m wirings 52 in the X direction are Dx1, Dx2,
... Dxm, and the Y-direction wiring 53 is Dy1, Dy
2, ... Dyn n wirings.

The material, the film thickness, and the wiring width are appropriately set so that a substantially uniform voltage is supplied to a large number of surface conduction electron-emitting devices.

The m X-direction wirings 52 and the n Y-direction wirings 53 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring (m and n are both positive integers). .

The interlayer insulating layer (not shown) is formed on the entire surface of the electron source substrate 51 on which the X-direction wiring 52 is formed or on a desired region of the electron source substrate 51. The X-direction wiring 52 and the Y-direction wiring 53 are drawn out as external terminals.

Further, device electrodes (not shown) of the surface conduction electron-emitting device 54 are electrically connected to the m X-direction wirings 52, the n Y-direction wirings 53, and the connection wires 55.

The surface conduction electron-emitting device may be formed either on the substrate or on an interlayer insulating layer (not shown).

As will be described later in detail, a surface conduction electron-emitting device 54 arranged in the X direction is formed on the X-direction wiring 52.
Is electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for scanning the row according to the input signal.

On the other hand, a modulation signal (not shown) for applying a modulation signal for modulating each row of the surface conduction electron-emitting devices 54 arranged in the Y direction according to the input signal to the Y-direction wiring 53. It is electrically connected to the signal generating means.

Further, the drive voltage applied to each element of the surface conduction electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the element.

In the above structure, individual elements can be selected and driven independently by simple matrix wiring.

Next, an image forming apparatus using the electron source of the simple matrix wiring manufactured as described above will be described with reference to FIGS. 10, 11 and 12. FIG. 10 is a diagram showing a basic configuration of the image forming apparatus, FIG. 11 is a fluorescent film, and FIG. 12 is a block diagram of a drive circuit for displaying in accordance with an NTSC television signal, including the drive circuit. Represents an image forming apparatus.

In FIG. 10, reference numeral 51 is an electron source substrate having an electron-emitting device formed on the substrate, 61 is a rear plate to which the electron source substrate 51 is fixed, and 66 is a fluorescent film 64 and a metal back 65 on the inner surface of a glass substrate 63. The face plate 62 on which is formed is a support frame, and an envelope 68 is constituted by these members.

Reference numeral 54 is an electron-emitting device, which corresponds to the above-mentioned electron-emitting portion. 52 and 53 are X-direction wiring and Y connected to a pair of device electrodes of the surface conduction electron-emitting device.
Directional wiring.

The envelope 68 is composed of the face plate 66, the support frame 62, and the rear plate 61 as described above, but the rear plate 61 is provided mainly for the purpose of reinforcing the strength of the electron source substrate 51. If the electron source substrate 51 itself has sufficient strength, the separate rear plate 61 is not necessary, and the support frame 62 is directly bonded to the electron source substrate 51, and the face plate 66, the support frame 62 and the electron source substrate You may comprise the envelope 68 with 51. In addition,
By installing an atmospheric pressure resistant support member called a spacer between the face plate 66 and the rear plate 61,
It is also possible to use the envelope 68 having sufficient strength against atmospheric pressure.

In FIG. 11, 72 is a phosphor. Phosphor 7
In the case of monochrome, 2 is composed of only phosphors, but in the case of a color phosphor film, it is composed of a black conductive material 71 called a black stripe or a black matrix depending on the arrangement of phosphors and a phosphor 72. The purpose of providing the black stripe (black matrix) is to provide each of the phosphors 72 of the three primary color phosphors necessary for color display.
That is to make the mixed color portions inconspicuous by blackening the colored portions between them and to suppress the deterioration of the contrast due to the reflection of external light on the fluorescent film 64. As a material for the black stripe, not only a commonly used material containing graphite as a main component, but also a material having conductivity and little transmission and reflection of light can be used.

As a method of applying the phosphor to the glass substrate 73, a precipitation method or a printing method is used regardless of whether it is monochrome or color.

A metal back 65 (FIG. 10) is usually provided on the inner surface side of the fluorescent film 64 (FIG. 10). The purpose of the metal back is to improve the brightness by specularly reflecting the light to the inner surface side of the light emitted from the phosphor to the face plate 66 side, to act as an electrode for applying an electron beam accelerating voltage, and This is to protect the phosphor from damage due to collision of negative ions generated in the enclosure. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after producing the fluorescent film, and then depositing Al by vacuum evaporation or the like.

The face plate 66 may be further provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 64 in order to enhance the conductivity of the fluorescent film 64.

At the time of performing the above-mentioned sealing, in the case of color, the phosphors of the respective colors and the electron-emitting device must be opposed to each other, and it is necessary to perform sufficient alignment.

The envelope 68 is 10 ⁻⁷ through an exhaust pipe (not shown).
The degree of vacuum is set to about Torr and sealing is performed. Also,
A getter process may be performed to maintain the degree of vacuum after the envelope 68 is sealed. This is a process of heating a getter placed at a predetermined position (not shown) immediately before or after sealing the envelope 68 to form a vapor deposition film.
The getter usually has Ba as a main component, and due to the adsorption action of the deposited film, for example, 1 × 10 ⁻⁵ Torr to 1 × 10 ^−7.
It maintains the degree of vacuum of Torr. The steps after energization forming of the surface conduction electron-emitting device are appropriately set.

Next, regarding the image forming apparatus constituted by using the electron source having the simple matrix arrangement type substrate, the NTS
A schematic configuration of a drive circuit for performing television display based on a C system television signal will be described with reference to the block diagram of FIG. 81 is the display panel, 82 is a scanning circuit, 83 is a control circuit, 84 is a shift register, 85 is a line memory, 86 is a sync signal separation circuit, 87 is a modulation signal generator, and Vx and Va are DC voltage sources. Is.

The function of each unit will be described below.

First, the display panel 81 has terminals Dox1 to Dox.
m, terminals Doy1 to Doyn, and a high-voltage terminal Hv to connect to an external electric circuit. Of these, terminals Dox1
In Doxm, an electron source provided in the display panel, that is, a group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns is sequentially driven row by row (n elements). A scanning signal for

On the other hand, a modulation signal for controlling the output electron beam of each element of the surface conduction electron-emitting devices of one row selected by the scanning signal is applied to the terminals Dy1 to Dyn. A DC voltage source Va supplies a DC voltage of, for example, 10 kV to the high-voltage terminal Hv, which supplies sufficient energy to excite the phosphor into the electron beam output from the surface conduction electron-emitting device. It is an acceleration voltage for applying.

Next, the scanning circuit 82 will be described. The circuit has m switching elements inside (indicated by S1 to Sm in the figure), and each switching element is either the output voltage of the DC voltage source Vx or 0 (V) (ground level). Select either one and display panel 81
The terminals Dx1 to Dxm are electrically connected. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 83, but can be actually configured by combining switching elements such as FETs.

The DC voltage source Vx is a constant voltage such that the driving voltage applied to the non-scanned element based on the characteristics of the surface conduction electron-emitting device (electron emission threshold voltage) is below the electron emission threshold. Is set to output.

Further, the control circuit 83 has a function of matching the operation of each part so that an appropriate display is performed based on the image signal input from the outside. The control signals Tscan, Tsft, and Tmry are generated for each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 86 described below.

The synchronizing signal separating circuit 86 is a circuit for separating a synchronizing signal component and a luminance signal component from an externally input NTSC television signal, and can be constructed by using a frequency separating (filter) circuit. The sync signal separated by the sync signal separation circuit 86 is composed of a vertical sync signal and a horizontal sync signal, as is well known, but it is shown here as a Tsync signal for convenience of description. on the other hand,
The luminance signal component of the image separated from the television signal is represented as a DATA signal for convenience sake, but this signal is the shift register 8
4 is input.

The shift register 84 is for serially / parallel converting the DATA signals serially input in time series for each line of the image, and operates based on the control signal Tsft sent from the control circuit 83. (That is, the control signal Tsft may be rephrased as the shift clock of the shift register 84).

The serial / parallel converted image data for one line (corresponding to driving data for n electron-emitting devices) is output from the shift register 84 as n parallel signals Id1 to Idn. .

The line memory 85 is a storage device for storing data for one line of an image only for a required time, and appropriately stores the contents of Id1 to Idn according to the control signal Tmry sent from the control circuit 83. The stored contents are output as Id1 to Idn and input to the modulation signal generator 87.

The modulation signal generator 87 outputs the image data I
A signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of d1 to Idn, and an output signal thereof is applied to the surface conduction electron emission devices in the display panel 81 through terminals Doy1 to Doyn. To be done.

As described above, the electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, as described above, the electron emission has a clear threshold voltage Vth, and the electron emission occurs only when a voltage higher than Vth is applied.

Further, for a voltage equal to or higher than the electron emission threshold value, the emission current also changes according to the change in the voltage applied to the element. The electron emission threshold voltage Vth or the degree of change of the emission current with respect to the applied voltage may be changed by changing the material, the configuration, or the manufacturing method of the electron emitting element.
In any case, the following can be said.

That is, when the pulsed voltage of this element is applied, for example, no electron emission occurs even if a voltage below the electron emission threshold is applied, but when a voltage above the electron emission threshold is applied, an electron beam is output. To be done. At that time, firstly, the intensity of the output electron beam can be controlled by changing the peak value Vm of the pulse. Second, it is possible to control the total amount of charges of the electron beam output by changing the pulse width Pw.

Therefore, as a method of modulating the electron-emitting device in accordance with the input signal, there are a voltage modulation method, a pulse width modulation method, and the like. To implement the voltage modulation method, the modulation signal generator 87 is fixed. A circuit of a voltage modulation system is used that generates a voltage pulse of a length but appropriately modulates the peak value of the pulse according to the input data.

In order to implement the pulse width modulation method, the modulation signal generator 87 generates a voltage pulse having a constant crest value, but a pulse for appropriately modulating the width of the voltage pulse according to the input data. A width modulation type circuit is used.

Through the series of operations described above, the image display device of the present invention can display television using the display panel 81. Although not particularly described in the above description, the shift register 84 and the line memory 85 may be either digital signal type or analog signal type, and the important point is that serial / parallel conversion and recording of image signals are performed. It may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separation circuit 86 into a digital signal, which is possible if the output section of 86 is equipped with an A / D converter. . Further, in relation to this, the circuit used for the modulation signal generator 87 is slightly different depending on whether the output signal of the line memory 85 is a digital signal or an analog signal.

First, the case of digital signals will be described. In the voltage modulation method, the modulation signal generator 87 is
For example, a well-known D / A conversion circuit may be used, and an amplification circuit or the like may be added as needed.

In the case of the pulse width modulation method, the modulation signal generator 87 outputs the output value of the counter and the counter for counting the number of waves output from the oscillator and the oscillator, for example, to the output value of the memory. It can be configured by using a circuit in which comparators for comparison are combined. If necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator up to the drive voltage of the surface conduction electron-emitting device may be added.

Next, the case of analog signals will be described. In the voltage modulation method, for example, a well-known amplifier circuit using an operational amplifier may be used as the modulation signal generator 87, and a level shift circuit or the like may be added if necessary. In the case of the pulse width modulation method, for example, a well-known voltage controlled oscillator (VCO)
May be used, and an amplifier for voltage amplification up to the drive voltage of the surface conduction electron-emitting device may be added if necessary.

In the image display device completed as described above, each of the electron-emitting devices thus has terminals outside the container Dox1 to Dox1.
Electrons are emitted by applying a voltage through Doxm and Doy1 to Doyn, and a high voltage is applied to the metal back 85 or the transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam and cause the fluorescent film 64 to pass through. An image can be displayed by colliding, exciting and emitting light.

The structure described above is a schematic structure necessary for manufacturing a suitable image forming apparatus used for display and the like, and the detailed parts such as the material of each member are not limited to the above contents. Instead, it is appropriately selected to suit the application of the image forming apparatus. Also, although the NTSC system is given as an example of the input signal, the input signal is not limited to this, and PAL,
Various systems such as the SECAM system may be used, or a TV signal (for example, a high-definition TV such as the MUSE system) that includes a larger number of scanning lines may be used.

Next, the ladder type electron source substrate and the image display device using the same described above will be described with reference to FIGS.
4 will be described.

In FIG. 13, 90 is an electron source substrate, and 91.
Is an electron-emitting device, and Dx1 to Dx10 of 92 are common wirings connected to the electron-emitting device. The electron-emitting device 91 is
A plurality of substrates are arranged in parallel in the X direction on the substrate 90 (this is called an element row). A plurality of this element row is arranged on the substrate to form a ladder type electron source substrate. By appropriately applying a drive voltage between the common wirings of each element row, each element row can be independently driven. That is, an electron beam having a voltage equal to or higher than the electron emission threshold may be applied to the element row that emits the electron beam, and a voltage equal to or lower than the electron emission threshold may be applied to the element row that does not emit the electron beam. Also, the common wiring Dx2 between each element row
˜Dx9 may have the same wiring, for example, Dx2 and Dx3.

FIG. 14 is a diagram showing the structure of an image forming apparatus provided with a ladder-type electron source. 100 is a grid electrode, 101 is a hole for passing electrons, and 102 is D
ox1, Dox2 ... Dox external terminals made of Dox, 103 is G1, G2 ... Gn connected to the grid electrode 100
And 104 is an electron source substrate in which the common wiring between each element row is the same wiring as described above. In addition,
The same reference numerals as those in FIGS. 10 and 13 denote the same members. The difference from the image forming apparatus having the simple matrix arrangement (FIG. 10) described above is that the grid electrode 100 is provided between the electron source substrate 90 and the face plate 66.

The grid electrode 100 is capable of modulating the electron beam emitted from the surface conduction electron-emitting device, and the electron beam is applied to the stripe-shaped electrodes provided orthogonally to the ladder-shaped element rows. A circular opening 101 is provided for each element in order to pass it. The shape and installation position of the grid are not necessarily as shown in FIG. 14, and a large number of passage openings may be provided in the form of a mesh as openings. For example, they may be provided around or near the surface conduction electron-emitting device. Good.

The external terminal 102 and the grid external terminal 103 are electrically connected to a control circuit (not shown).

In this image forming apparatus, the modulation signals for one line of the image are simultaneously applied to the grid electrode columns in synchronization with the sequential driving (scanning) of the element rows one column at a time so that each electron beam Control the irradiation to the phosphor and display the image 1
Can be displayed line by line.

Further, according to the present invention, it is possible to provide an image forming apparatus suitable for not only a display device for television broadcasting but also a display device such as a video conference system and a computer. Further, it can be used as an image forming apparatus as an optical printer including a photosensitive drum or the like.

[0102]

【Example】

Example 1 An example of manufacturing an electron source using a surface conduction electron-emitting device and matrix wiring by the method of the present invention will be described with reference to FIGS.

In FIG. 1, reference numeral 1 is a substrate made of soda-lime glass. After forming a metal thin film by a sputter deposition method, element electrodes 2 and 3 were formed by a photolithographic etching method. The material is 10 Å with a thickness of 50Å
It consists of a 00Å Ni thin film, and the electrode spacing is 2 at the center.
The width is 0 μm and the electrode width is 300 μm. The lower wiring electrode 5 is Ag
It is a printed wiring having a thickness of about 7 μm obtained by printing and firing paste ink, and is connected to the element electrode 3.

Reference numeral 6 denotes a strip-shaped insulating layer formed by baking a paste containing glass as a main component after printing and orthogonal to the lower printed wiring, and a recess 7 is provided at the intersection with the device electrode 2. There is.

Reference numeral 8 denotes an upper wiring electrode, which is formed on the insulating layer 6 and is electrically connected to the element electrode 2 by the recess 7, and is formed by firing the printed metal paste after printing it into a predetermined pattern. To be done.

Reference numeral 4 denotes a thin film of Pd fine particles having a thickness of about 200 Å obtained by coating and baking an organometallic solution, which is coated and formed on the entire surface and then patterned by photolithography. As shown in FIG. It was formed at a position above 2.3.

A glass substrate 21 made of soda lime glass is opposed to the substrate 1 with a distance of 5 mm. Reference numeral 22 denotes a fluorescent substance, which is arranged on the substrate 21 and is formed at a position corresponding to an electrode interval portion composed of the device electrodes 2 and 3 arranged on the substrate 1 facing each other. The fluorescent substance 22 is formed by mixing a photosensitive resin with a fluorescent substance to form a slurry, coating and drying it, and then patterning it by a photolithographic method. In 23, after performing the filming process on the phosphor,
Form an Al thin film with a thickness of about 300Å by vacuum evaporation,
It is a metal back obtained by burning this to burn off the film layer. A device including the device formed on the substrate 1 is called an device substrate, a device including the phosphor formed on the glass substrate 21 and a metal back is called a face plate.

After arranging the above in a vacuum envelope, a voltage is applied between the upper and lower wiring electrodes 8 and 5 to energize the thin film 4 between the device electrodes 2 and 3, and a crack-shaped electron emitting portion is formed. Got 9.

After that, an electron extraction voltage of 3 kV is applied with the metal back 23 as an anode electrode, and the device electrodes 2 and 3 are applied to the electron emission portion 9 through the upper and lower wiring electrodes 8.5.
When a voltage of 4V was applied, electrons were emitted. By irradiating the phosphor 22 with the emitted electrons and adjusting the amount of emitted electrons, the phosphor 22 was made to emit light at an arbitrary intensity and an image could be displayed.

The electron source of this example was 40 cm square, and the electron-emitting devices were arranged in a matrix with a device array pitch of 1 mm and a device count of 350 × 350. In addition, the phosphors 22 in which the respective colors of R, G, and B are separately coated are arranged on the face plate corresponding thereto.

As a result of producing ten electron sources having 350 × 350 elements, no element failure due to unconnection between the upper wiring electrode and the element electrode did not occur.

(Embodiment 2) FIG. 4 shows another example of the electron source manufactured by the manufacturing method of the present invention.

In the electron source shown in this figure, the element electrode 3 has a pattern longer than that of the first embodiment, and thereby the upper electrode 8 is connected at the position of the concave portion 7 on the opposite side with the strip-shaped insulating layer 6 interposed therebetween. It is structured.

With such a structure, the photomask used when patterning the device electrodes 2 and 3 by the photolithographic method in the method of Example 1 is changed, and the pattern of the screen plate used for printing the insulating layer 6 is changed. Can be made with.

With such a structure, the width of the recess 7 can be widened, and the tolerance of the positional deviation of the insulating layer 6 during printing can be increased.

That is, when the width of the recess 7 is widened in the structure as in the first embodiment, if the amount of positional deviation during printing of the insulating layer is large, not only the element electrode 2 but also the element electrode 3 and the upper wiring 8 may come into contact with each other. Cause However, as in the structure shown in FIG. 4, the possibility of contact between the element electrode 2 and the upper wiring 8 can be reduced by connecting the recess 7 on the opposite side via the insulating layer 6.

(Embodiment 3) FIG. 5 shows a pattern of device electrodes 2 and 3 which is a main part of a third example of an electron source manufactured by the method of the present invention.

That is, the electron source of this example uses the structure of the insulating layer in which the width of the recess 7 in Example 2 is widened, and
As shown in (3), the structure is such that the connection portion of the device electrode 3 is widened. This makes it possible to reduce the electrical resistance at the connection between the device electrode 3 and the upper wiring 8, and improve the electrical characteristics of the electron-emitting device.

[0119]

As described above, in the manufacture of the electron source, the display panel and the image forming apparatus using the surface conduction electron-emitting device, the recess is formed in the strip-shaped insulating layer arranged at the position where the upper wiring is arranged. By providing the connection between the upper wiring and the element electrode at the provided portion, it is possible to reduce the occurrence rate of defects at the connection point even when the insulating layer is formed by the printing method.

As a result, a low cost printing method can be used in place of the costly photolithographic processing, and a large cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a part of an example of an electron source manufactured by the method of the present invention.

FIG. 2 is a schematic cross-sectional view of an example of a display panel manufactured using the electron source of FIG.

FIG. 3 is a process drawing showing a procedure for manufacturing the electron source of FIG.

FIG. 4 is a schematic plan view showing a part of another example of the electron source manufactured by the method of the present invention.

FIG. 5 is a schematic diagram showing an element electrode pattern in an electron source of Example 3.

FIG. 6 is a schematic plan view of a conventional surface conduction electron-emitting device.

FIG. 7 is a schematic diagram showing an example of the configuration of a surface conduction electron-emitting device in an electron source manufactured by the method of the present invention,
(A) is a plan view and (b) is a sectional view.

FIG. 8 is a graph showing voltage waveforms during energization forming during manufacturing of the surface conduction electron-emitting device, where (a) shows a case where the pulse peak value is constant and (b) shows a case where the pulse peak value increases.

FIG. 9 is a schematic partial plan view showing an example of an electron source substrate having a simple matrix arrangement.

FIG. 10 is an image forming apparatus 1 manufactured by the method of the present invention.
It is a schematic block diagram of an example.

FIG. 11 is a schematic partial view showing a structure of a fluorescent film,
(A) is provided with a black stripe, (b)
[Fig. 3] is a diagram of a device provided with a black matrix.

FIG. 12 is an image forming apparatus 1 manufactured by the method of the present invention.
It is a drive circuit in an example, Comprising: It is a block diagram of the drive circuit for displaying according to the television signal of NTSC system.

FIG. 13 is a schematic partial plan view of an electron source substrate in a ladder arrangement.

FIG. 14 is an image display device 1 manufactured by the method of the present invention.
It is a general | schematic perspective view which fractured | ruptured a part which shows an example.

[Explanation of symbols]

 1 Substrate 2 Element Electrode 3 Element Electrode 4 Thin Film 5 Lower Wiring Electrode 6 Insulator 7 Recess 8 Upper Wiring Electrode 9 Electron Emitting Part 21 Glass Substrate 22 Phosphor 23 Metal Back 31 Substrate 32 Electron Emitting Part Forming Thin Film 33 Electron Emitting Part 41 Insulating substrate 42 Element electrode 43 Element electrode 44 Thin film 45 Electron emission part 51 Electron source substrate 52 X direction wiring 53 Y direction wiring 54 Surface conduction electron emission element 55 Connection 61 Rear plate 62 Support frame 63 Glass substrate 64 Fluorescent film 65 Metal Back 66 Face plate 67 High voltage terminal 68 Envelope 71 Black conductive material 72 Fluorescent material 73 Glass substrate 81 Display panel 82 Scanning circuit 83 Control circuit 84 Shift register 85 Line memory 86 Synchronous signal separation circuit 87 Modulation signal generator 90 Electron source substrate 91 electron-emitting device 92 common wiring 1 0 grid electrode 101 holes 102 vessel terminals 103 vessel terminals 104 electron source substrate

Claims (9)

[Claims] 1. An electron-emitting device having lower wirings and upper wirings formed in a matrix on a substrate through a strip-shaped interlayer insulating layer, and having an element electrode pair on the substrate at the intersection of the upper and lower wirings. In the arranged electron source, the upper wiring is formed on the strip-shaped interlayer insulating layer along the insulating layer, and the insulating layer has a recess in a direction parallel to the substrate surface on the electron-emitting device, An electron source, wherein the upper wiring is connected to one of the device electrodes of the electron-emitting device in the recess. 2. The electron source according to claim 1, wherein the electron-emitting device is a surface conduction electron-emitting device having a conductive thin film having an electron-emitting portion between a pair of electrodes. 3. The electron source according to claim 1 and the substrate on which the phosphor is arranged so as to face the substrate overlap with each other via an envelope, and are formed by these both substrates and the envelope. A display panel whose interior space is evacuated. 4. An image forming apparatus in which at least a drive circuit is connected to the display panel according to claim 3. 5. A step of forming an electron-emitting device having an element electrode pair on a substrate, a step of forming a lower wiring connected to one electrode of the element electrode pair on the substrate, 3) A step of forming an upper wiring connected to the other electrode of the element electrode pair so as to form a matrix shape with the lower wiring via a strip-shaped interlayer insulating layer on the lower wiring. In the method of manufacturing an electron source, the strip-shaped interlayer insulating layer is formed in the same direction as the upper wiring in the shape having a recess in a direction parallel to the substrate surface on the electron-emitting device, and the upper wiring and the upper wiring are formed in the recess. A method of manufacturing an electron source, which comprises connecting to one of device electrodes of an electron-emitting device. 6. The method for manufacturing an electron source according to claim 5, wherein the electron-emitting device is a surface-conduction electron-emitting device having a conductive thin film having an electron-emitting portion between a pair of electrodes. 7. The method of manufacturing an electron source according to claim 5, wherein the belt-shaped interlayer insulating layer is formed by a printing method. 8. The electron source according to any one of claims 5 to 7 and a substrate on which a phosphor is disposed so as to face the substrate are stacked via an envelope, and both the substrate and the outside A method of manufacturing a display panel in which an internal space formed by an envelope is evacuated. 9. A method of manufacturing an image forming apparatus, wherein at least a drive circuit is connected to the display panel according to claim 8.