JPH08250019A - Surface conduction electron emitting element, electron source substrate and image forming device and manufacture thereof - Google Patents

Abstract

PURPOSE: To prevent element characteristics from being scattered by forming paired electrodes by a printing method, irradiating a laser beam onto a space section sandwiched by the paired electrodes, and thereby forming the electron electrodes where a space between the element electrodes and the thickness of each film are accurate and uniform. CONSTITUTION: In the formation of element electrodes for surface conduction electrons, paired element electrodes are formed over a substrate 1 made of a flat blue glass and the like by using an element electrode pattern print by a screen printing method with MOD paste 2 composed of Au material and the like first. Following which, a laser beam 5 such as Nd:YAG second higher harmonics and the like is irradiated to the element electrode space section 6 of the substrate 1 with about 10μm intervals by scanning, so that blotted areas formed by the printing method, are thereby removed. By this constitution, the element electrodes can be formed, in which a space between the element electrodes and the thickness of a film are uniform. An electron source substrate and an image forming device are manufactured by using the aforesaid electron emitting element.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In recent years, various manufacturers have been researching and developing flat panel displays as an alternative to CRT displays in accordance with the increasing area and higher definition of displays. Flat panel displays include plasma displays, liquid crystal panel displays,
There are surface conduction electron-emitting device displays and the like.

Among them, a surface conduction electron-emitting device display having a good viewing angle, brightness and the like is obtained by applying a current in equilibrium to the film surface of a thin film of a small area formed on a substrate.
It utilizes the phenomenon of electron emission. As an example of the surface conduction electron-emitting device, Erinson's report (M.
I. Elinson, Radio Eng. Electron Phys., 10 (1965))
And the like.

An image display device can be manufactured by combining such an electron-emitting device and a phosphor and drawing.

FIG. 2 shows a Hartwell device structure as a typical device structure of these surface conduction electron-emitting devices. In the figure, 1 is a substrate, 4 is a conductive thin film, made of metal oxide or the like formed by sputtering in an H-shaped pattern, and the electron emitting portion 5 is formed by a process called forming described later. . Here, since it is necessary to apply a voltage uniformly to the electron-emitting device, it is desirable that the device electrodes have accurate and uniform device electrode intervals and film thicknesses.

Since these surface conduction electron-emitting devices have a simple structure, a large number of them can be arranged.
The image forming apparatus is configured by connecting the opposing element electrodes.

Since electron emission must be performed in a vacuum,
The electron source substrate on which the wiring and the electron emitting portion are formed and the face plate provided with the fluorescent pair are opposed to each other, and sealed with a frit glass at a temperature of about 400 ° C. or more through a support frame to form a vacuum container portion. To form.

After the above-mentioned sealing step, the wiring end outside the vacuum container, which is called mounting, is electrically connected to the electric drive unit, and then an electric field is applied to the thin film, which is called forming, to locally form the thin film. Destroyed, deformed or altered,
An electron emitting portion is formed through a process of making it electrically high resistance. By causing a current to flow in parallel with the film surface of the electron emitting portion, electron emission occurs, and the electrons collide with the phosphor of the face plate to display an image.

[0009]

However, the electron source substrate of these surface conduction electron-emitting device displays has the following problems.
It was produced using a thin film process (Japanese Patent Laid-Open No. 3-2
0941), in the thin film process, the number of steps is large and the cost is very high in order to increase the area.

On the other hand, it has been attempted to use a printing process such as screen printing to prepare an electron source substrate. However, since the device electrode applies a uniform voltage to the electron-emitting device, the device electrode is not used for the electron-emitting device. Since the voltage is applied uniformly, the device electrode spacing must be accurate and the film thickness must be uniform. However, in screen printing, the paste may bleed to cause large variations in device characteristics, and the surface conduction electron-emitting device display using the manufacturing method has a low manufacturing yield.

Therefore, an object of the present invention is to form device electrodes with accurate and uniform device electrode intervals and film thicknesses, which can reduce variations in device characteristics, which leads to cost reduction and improved manufacturing yield. An object of the present invention is to provide a method for manufacturing a conduction electron-emitting device, an electron source substrate using the electron-emitting device, and a method for manufacturing an image forming apparatus.

[0012]

The present invention includes a step of forming at least one pair of device electrodes on an insulating substrate so as to face each other, and a process of forming a thin film including an electron emitting portion between the device electrodes. In the method for manufacturing a surface conduction electron-emitting device, the device electrode pair is formed by printing, and then the gap between the electrode pair is formed by laser irradiation. A method for manufacturing a surface conduction electron-emitting device is provided.

[0013]

3 (a) and 3 (b) are a schematic plan view and a sectional view, respectively, showing the basic structure of the surface conduction electron-emitting device according to the present invention. In FIG. 3, 31 is a substrate,
32 and 33 are device electrodes, 34 is a conductive thin film, and 35 is an electron emitting portion.

As the substrate 31, quartz glass, glass having a small content of impurities such as Na, soda lime glass, a glass substrate having SiO ₂ laminated on the surface thereof, and a ceramic substrate such as alumina are used.

There is only one material for the device electrodes 32 and 33.
A general conductor is used, for example, Ni, Cr, Au, M
metal such as o, W, Pt, Ti, Al, Cu, Pd
Are their alloys, or alloys of these metals, or
Is Pd, Ag, Au, RuO ₂, Pd-Ag, etc.
Printed conductor composed of ruthenium oxide and glass, In
₂0₃-SnO₂Transparent conductors, etc., and polysilico
It is appropriately selected from semiconductors and the like.

The element electrode spacing L is preferably several hundred Å to several hundred μm. Further, it is desirable that the voltage applied between the device electrodes is low, and it is necessary to manufacture the device with good reproducibility.

The device electrode length W is several μm to several hundreds μm in view of the resistance value of the electrodes and electron emission characteristics, and the film thickness d of the device electrodes 32 and 33 is preferably several hundred Å to several μm.

Not limited to the structure shown in FIG. 3, in the present invention, a conductive thin film and a device electrode may be formed on the substrate in this order.

Here, a description will be given of a case where the device electrode forming step, which is a feature of the present invention, is performed by a screen printing method using an organic metal paste (hereinafter referred to as MOD paste) as a typical example.

The MOD paste is Au-MOD, Pt-
It is possible to use an organic metal compound containing various metals as a substituent, such as MOD or AuPd-MOD, dissolved in oil such as terpineol to adjust the viscosity to about 10,000 cps to 1 million cps.

Such a MOD paste is applied by screen printing on the substrate using a plate having an element electrode pattern, and then heat treatment is performed at 600 ° C. in air or oxygen atmosphere to remove organic substances from the paste. To do.

Among the element electrodes manufactured as described above, there are some in which the paste is bleeding or is thinly connected due to the printing pressure, the viscosity of the paste, and the like.

Therefore, the element electrode gap portion 36 of the element is irradiated with a laser to selectively remove the paste.

Considering that a laser used for processing melts and evaporates a conductor such as a metal, at least 1 × 10 ⁷ is considered.
With a power density of about W / cm ² or more, a laser suitable for the processing may be appropriately selected from the wavelength region of 0.2 to 10 μm in consideration of the absorption coefficient for the wavelength of the material of the processing target and the laser wavelength. The type of laser is not particularly limited.

As a method of irradiating the paste with a laser beam, a laser beam is converged by a lens and processed by changing a relative position of the paste and the laser beam, and a thick laser beam is shaped by a mask to paste. A method of irradiating an arbitrary laser beam on the surface can be applied.

Next, a conductive thin film 34 is formed on the device electrode manufactured by the above method.

The conductive thin film 34 is particularly preferably a fine particle film composed of fine particles in order to obtain electron emission characteristics. The thickness of the conductive thin film 34 is the step coverage of the device electrodes 32 and 33.
The resistance value between the device electrodes 32 and 33, and further, the energization forming conditions to be described later are appropriately set.
Is. The sheet resistance value is 10 ³ to 10 ⁷ Ω / □.

The material forming the conductive thin film 34 is
Pd, Pt, Ru, Ag, Au, Ti, In, Cu, C
Metals such as r, Fe, Zn, Sn, Ta, W, Pb; Pd
Oxides such as O, SnO ₂ , In ₂ O ₃ , PbO and Sb ₂ O ₃ ; HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , G
Borides such as dB ₄ ; TiC, ZrC, HfC, TaC,
Carbides such as SiC and WC; nitrides such as TiN, ZrN 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 where the fine particles are dispersed and arranged but also in a state where the fine particles are adjacent to each other or overlap each other (island). (Including the shape), and the particle size of the fine particles is several Å to several thousand Å, preferably 10 Å to 200 Å.

The electron emitting portion 35 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 34. Further, the electron emitting portion 35 and the conductive thin film 34 in the vicinity thereof may contain carbon or a carbon compound.

The energization forming is performed by the device electrodes 32 and 33.
An electric power is supplied from a power source (not shown) in the meantime to locally break, deform or alter the conductive thin film 34 to form a portion having a changed structure. The part where the structure is locally changed is referred to as an electron emission part 35. An example of the voltage waveform of energization forming is shown in FIG.

The voltage waveform is preferably a pulse shape, and the voltage pulse having a constant pulse peak value is continuously applied (FIG. 4A) and the voltage pulse is applied while increasing the pulse peak value (FIG. 4A). 4 (b)). First,
A case where the pulse peak value is a constant voltage (FIG. 4A) will be described.

In FIG. 4A, 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. 4 (b) are shown 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.

The carbon or carbon compound is graphite (both single crystal and polycrystal) or amorphous carbon (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 step and the activation treatment means, for example, about 10 ⁻⁶ Torr.
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 image forming apparatus of the present invention will be described.

The electron source substrate used in the image forming apparatus is formed by arranging a plurality of surface conduction electron-emitting devices on the substrate.

As a method of arranging the surface conduction electron-emitting devices, the surface conduction electron-emitting devices are arranged in parallel, and both ends of each device are connected by a ladder arrangement (hereinafter, ladder 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 number of X-direction wirings 52 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 thereof. The X-direction wiring 52 and the Y-direction wiring 53 are drawn out as external terminals.

Further, the 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, the surface conduction electron-emitting devices 54 arranged in the X direction are arranged 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 driving 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 using only 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. 6, 7 and 8. FIG. 6 is a diagram showing a basic configuration of the image forming apparatus, FIG. 7 is a fluorescent film, and FIG. 8 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. 6, 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 the envelope 68 is constituted by these members.

Reference numeral 54 denotes an electron emitting element, which corresponds to the electron emitting portion in FIG. 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. Furthermore,
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. 7, 72 is a phosphor. Phosphor 72
In the case of monochrome, it is composed of only the phosphor, 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 the phosphor and a phosphor 72. In the case of color display, the purpose of providing the black stripes (black matrix) is to make the color-separated portion between the phosphors 72 of the three primary color phosphors black so as to make the color mixture inconspicuous, and the phosphor film 64. This is to suppress the deterioration of the contrast due to the reflection of external light. 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. 6) is usually provided on the inner surface side of the fluorescent film 64 (FIG. 6). 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. For the metal back, after the fluorescent film is manufactured, the inner surface of the fluorescent film is smoothed (usually called filming), and then Al
Can be manufactured by depositing 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.

When performing the above-mentioned sealing, in the case of a 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.
The vacuum degree of Torr is maintained. The steps after energization forming of the surface conduction electron-emitting device are appropriately set.

Next, regarding the image forming apparatus constructed 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 an unscanned element is equal to or lower than the electron emission threshold based on the characteristics of the surface conduction electron-emitting element (electron emission threshold voltage). 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 an 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 NTSC television signal inputted from the outside, and can be constituted 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 the image for a required time, and stores the contents of Id1 to Idn as appropriate in accordance with 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 the present element is applied, for example, electron emission does not occur 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 according to the input signal, a voltage modulation method, a pulse width modulation method or the like can be mentioned. 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 peak 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 sync 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 if necessary.

Further, in the case of the pulse width modulation method, the modulation signal generator 87 outputs the output value of the counter and the counter of the counter which counts the number of waves output from the high speed oscillator and the oscillator, for example. 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 an analog signal 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 or 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 will be described with reference to FIGS. 9 and 10.
Will be explained.

In FIG. 9, 90 is an electron source substrate, 91 is an electron-emitting device, and 92 Dx1 to Dx10 are common wirings connected to the electron-emitting device. A plurality of electron-emitting devices 91 are arranged in parallel in the X direction on the substrate 90 (this is called a device row). Arrange a plurality of this element row on the substrate,
It becomes 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 to each element row is
For example, Dx9 and Dx2 and Dx3 may have the same wiring.

FIG. 10 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,
6 and 9 indicate the same members. The difference from the image forming apparatus (FIG. 6) having the simple matrix arrangement described above is
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. A circular opening 101 is provided for each element in order to pass it. The shape and installation position of the grid may not necessarily be as shown in FIG. 10, and a large number of passage openings may be provided in the form of a mesh as openings. For example, the grid 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, a modulation signal for one line of an image is simultaneously applied to the grid electrode column 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.

[0097]

【Example】

(Embodiment 1) FIG. 1 is a view best showing the features of the present invention, and a method for forming a device electrode will be described with reference to this drawing.

First, in FIG. 1A, a plate having a device electrode pattern (device electrode interval 20 μm) of a screen printing method was used on a substrate 1 made of cleaned soda-lime glass, and Au was used.
A device electrode pair was formed with the MOD paste 2 of the material. At this time, the Au paste partly bleeded, and in some extreme cases, the Au paste was connected. The paste material is A
The same applies to Cu, Ag, etc., as well as u.

Next, in FIG. 1B, the laser beam 8 of the second harmonic of Nd: YAG is irradiated to the element electrode interval portion of the substrate 1 by scanning at 10 μm to remove the bleeding portion of FIG. And molded. The thickness of the paste in the bleeding part is
Since it is much thinner than the film thickness of the device electrode portion, there is little drows by the laser. As such, FIG. 1 (c)
A device electrode having a uniform device electrode interval and a uniform film thickness was formed as shown in FIG.

In this embodiment, the laser uses the second harmonic of Nd: YAG, but the laser is not limited to this, and Nd: YAG fundamental wave, third harmonic, KrF excimer, etc. can be used in the same manner. The gap width can be controlled at 1 to 50 μm. Further, instead of scanning, it is possible to irradiate the pattern with a laser using a mask.

As a result of evaluating the characteristics by using the device electrode according to this manufacturing method, the variation was small and a good result was given.

(Example 2) In this example, an electron source substrate for a surface conduction electron-emitting device display and an image forming apparatus were manufactured by using the device electrodes manufactured by the manufacturing method of Example 1.

FIG. 2 shows a part of an electron source substrate of a surface conduction electron-emitting device display having a simple matrix electron arrangement.

First, the row-direction wiring 6, the interlayer insulating film 7 and the column-direction wiring 8 were sequentially formed on the glass substrate having the device electrodes 4 formed in Example 1 by the screen printing method. Next, electron-emitting devices 9 using Pd were formed in a matrix so as to overlap with the device electrodes.

Here, as the method of forming the wirings 6 and 8, it is possible to form thinly by screen printing and then thickly form by plating.

Thereafter, the rear plate having the wiring and the electron emitting portion formed thereon and the face plate provided with the phosphor are opposed to each other, the supporting frame is opened, and the frit glass is sealed at a temperature of about 400 ° C. or higher.

After the sealing step, the above-mentioned mounting and forming were performed to form an electron emitting portion. When a current was passed in parallel with the film surface of the electron-emitting portion and an image was displayed, uniform brightness was obtained.

In this embodiment, the element electrode is first formed, but the wiring and the insulating layer may be formed first by the printing method, and then the element electrode may be formed by the method of the first embodiment.

By the above manufacturing method, the surface conduction electron-emitting device display could be manufactured with high yield.

(Embodiment 3) In this embodiment, the electron source substrate of the surface conduction electron-emitting device display of the ladder type electron arrangement and the image forming apparatus are manufactured by using the device electrode manufactured by the method of the embodiment 1. explain.

FIG. 12 shows a part of the electron source substrate of the surface conduction electron-emitting device display of the ladder type electron arrangement.

First of all. The wiring 10 was formed by the screen printing method on the glass substrate on which the device electrode was manufactured in Example 1.
Next, the electron-emitting devices 9 were formed in a matrix so as to overlap the device electrodes.

Here, as the method of forming the wiring 10, it is possible to form it thin by screen printing and then form it thickly by plating.

Thereafter, sealing, mounting and forming were performed in the same manner as in the electron source substrate of the matrix type electronic arrangement of Example 2, and an image was displayed, and uniform brightness was obtained.

In this embodiment, the element electrode is first formed, but the wiring and the insulating layer may be formed first by the printing method, and then the element electrode may be formed by the method of the first embodiment.

By the manufacturing method as described above, the surface conduction electron-emitting device display could be manufactured with high yield.

[0117]

As described above, according to the manufacturing method of the present invention, it is possible to form element electrodes having accurate and uniform element electrode intervals and film thicknesses, and variations in element characteristics are reduced. Further, in the surface conduction electron-emitting device display using the device electrode formed by the method, the cost can be reduced,
Furthermore, it is possible to improve the manufacturing yield.

[Brief description of drawings]

FIG. 1 is a method 1 for manufacturing a surface conduction electron-emitting device according to the present invention.
It is process drawing which shows an example.

FIG. 2 is a schematic plan view of a conventional surface conduction electron-emitting device.

3A and 3B are schematic diagrams showing an example of the configuration of a surface conduction electron-emitting device manufactured by the method of the present invention, FIG. 3A being a plan view and FIG. 3B being a sectional view.

FIG. 4 is a graph showing voltage waveforms during energization forming during manufacturing of the surface conduction electron-emitting device of the present invention,
(A) shows the case where the pulse peak value is constant, and (b) shows the case where the pulse peak value increases.

FIG. 5 is a schematic partial plan view showing an example of an electron source having a simple matrix arrangement.

FIG. 6 is a schematic configuration diagram of an example of an image forming apparatus manufactured by the method of the present invention.

FIG. 7 is a schematic partial view showing a configuration 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. 8 is a block diagram of a drive circuit in one example of the image forming apparatus manufactured by the method of the present invention, which is for displaying according to an NTSC television signal.

FIG. 9 is a schematic partial plan view of an electron source having a ladder arrangement.

FIG. 10 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.

FIG. 11 is a schematic view showing a part of a rear plate of an example of a surface conduction electron-emitting device display with a simple matrix type electron arrangement manufactured by the method of the present invention.

FIG. 12 is a schematic view showing a part of a rear plate of an example of a surface conduction electron-emitting device display having a ladder type electron arrangement manufactured by the method of the present invention.

[Explanation of symbols]

 1 Glass Substrate 2 Paste 3 Conductive Thin Film 4 Element Electrode 5 Laser Beam 6 Element Electrode Interval 7 Row Direction Wiring 8 Interlayer Insulating Film 9 Column Direction Wiring 10 Electron Emitting Element 11 Wiring 31 Substrate 32, 33 Element Electrode 34 Conductive Thin Film 35 Electron Emission part 51 Electron source substrate 52 X-direction wiring 53 Y-direction wiring 54 Surface conduction electron-emitting device 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 Phosphor 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 emission element 92 Common wiring 100 Grid electrode 101 Void 102 Outer terminal 10 3 Outer terminal 104 Electron source substrate

Claims (7)

[Claims] 1. A surface conduction electron emission device comprising: a step of forming at least one pair of device electrodes facing each other on an insulating substrate; and a step of forming a thin film including an electron emission portion between the device electrodes. In the element manufacturing method, the element electrode pair is formed by forming the electrode pair by a printing method and then performing molding by laser irradiation on a gap portion sandwiched by the electrode pair. Method for manufacturing surface conduction electron-emitting device. 2. A plurality of surface conduction electron-emitting devices are formed on an insulating substrate by the method according to claim 1, and each pair of device electrodes facing each other is connected to a row-direction wiring on the substrate. A method of manufacturing an electron source substrate, which is connected by a column-direction wiring laminated via an insulating layer. 3. A method of manufacturing an electron source substrate, wherein a plurality of surface conduction electron-emitting devices are formed in parallel on an insulating substrate by the method according to claim 1, and both ends of each device are connected by wiring. 4. An electron source substrate is formed by at least the method according to claim 2, a rear plate having the electron source substrate is formed, and the rear plate and a face plate having a fluorescent film are formed. A method of manufacturing an image forming apparatus, comprising a step of joining both plates via a support frame so as to face each other. 5. A surface conduction electron-emitting device manufactured by the method according to claim 1. 6. An electron source substrate manufactured by the method according to claim 2. 7. An image forming apparatus manufactured by the method according to claim 4.