JPH09198999A - Electron source substrate and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relatively fine and stable display image suppressing the expanse and fluctuation of an emitted electron beam by preventing the insulating layer on a substrate from being exposed on the surface of the electron source substrate at the periphery of an electron emission section. SOLUTION: The lower wiring 102 made of Cr/Cu/Cr is formed at the desired position by the vacuum deposition method or the like on a cleaned blue sheet glass 101. An inter-layer insulating layer 103 of SiO2 and an element electrode 104 of Ti/Pt are formed in sequence by the sputtering method or the like. Cr/Au is formed by the lift-off method or the like at the positions of the upper wiring 105 and connecting wiring 106. The SiO2 at the positions other than the forming positions of an electron emission section forming thin film 17 and the upper and connecting wirings is removed by the dry etching method, then organic Pd is sprayed and baked to form the electron emission section forming thin film 107 made of fine grains of Pd, and it is forming-processed to form an electron emission section as an electron source substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron source substrate and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitting devices, a thermionic electron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type (hereinafter abbreviated as FE type), a metal / insulating layer / metal type (hereinafter abbreviated as MIM type), and a surface conduction type electron emission element.

As an example of the FE type, W. P. Dyke &
W. W. Dolan, "Field Emissi
on ”, Advance in Electron P
hysics, 8, 89 (1956) or C.I. A.
Spindt, "Physical Property"
es of thin-film field emi
session cats with with mollyb
denium "J. Appl. Phys., 47, 52.
48 (1976) and the like are known. Examples of the MIM type include C.I. A. Mead, "The tunnel-em
ision amplifier, J.I. Appl. Ph
ys. , 32, 646 (1961) and the like are known.
Examples of surface conduction electron-emitting devices include those described in M.S. I. Eli
nson, Radio Eng. Electron P
hys. , 10, (1965).

[0004] The surface conduction electron-emitting device utilizes the phenomenon that electron emission occurs when a current flows in a small-area thin film formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, one using a SnO2 thin film by Ellison et al., One using an Au thin film [G. Dittmer: "thin Solid Fi
lms ”9, 317 (1972)], In203 / Sn
O2 thin film [M. Hartwell and
C. G. FIG. Fonsted: "IEEE Trans.E
D Conf. , 519 (1972)], by carbon thin film [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1,
22 (1983)].

As a typical device configuration of these surface conduction electron-emitting devices, the above-mentioned M. The Hartwell device structure is shown in FIG. In the figure, 401 is a substrate, and 404 is a conductive thin film, which is composed of a metal oxide thin film formed by sputtering on an H-shaped pattern, and an electron emission portion 405 is formed by an energization process called energization forming described later. It The element electrode interval L in the figure is 0.5 to 1 m.
m and W ′ are set at 0.1 mm. Since the position and shape of the electron emitting portion 5 are unknown, they are shown as a schematic diagram.

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 405 has generally been formed in advance by conducting a current called a conductive forming process on the conductive thin film 404 before emitting electrons. That is, the energization forming is performed by applying a direct current voltage or a very slow rising voltage, for example, about 1 V / min to both ends of the conductive thin film 404 to locally energize the conductive thin film, electrically or electrically deform it. That is, the electron emitting portion 405 having a high resistance is formed. The electron emission unit 405
A crack is generated in a part of the conductive thin film 404, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the energization forming has the above-mentioned conductive thin film 404.
Electrons are emitted from the electron emitting portion 5 by applying a voltage to the element and passing a current through the element.

Since the surface conduction electron-emitting device described above has a simple structure and is easy to manufacture, it has an advantage that many devices can be arrayed over a large area. Therefore, various applications that can make full use of this feature are being researched. For example, a display device such as a charged beam source and an image display device can be used (Japanese Patent Laid-Open No. 6-342636).

3A and 3B show an example of an electron source substrate in which the above-described surface conduction electron-emitting devices are arranged in a lattice on the substrate. FIG. 3A is a plan view seen from above, and FIG. 3B is a plan view. A sectional view taken along a straight line AA ′ in FIG.

Thin film 30 for forming an electron-emitting portion of each electron-emitting device
One of a pair of device electrodes 304 facing each other across the upper electrode 7 is an upper wiring 305 along the upper surface of the insulating layer 303 on the substrate 301.
Connection wiring 3 which is connected to the other and vertically penetrates the insulating layer 303.
It is in contact with the lower wiring 302 along the lower surface of the insulating layer 303 via 06.

Reference numeral 301 denotes quartz glass, glass having a reduced content of impurities such as Na, soda-lime glass, a glass substrate having SiO2 laminated on the soda-lime glass by a sputtering method, and an insulating substrate such as ceramics such as alumina. N
i, Cr, Au, Mo, W, Pt, Ti, Al, Cu,
Metals or alloys such as Pd and In203-SnO2
A conductive lower conductor such as a transparent conductor and a semiconductor conductor material such as polysilicon or a printed conductor made of glass, 303 is an interlayer insulating layer such as SiO 2, Si 3 N 4, 304 is an element electrode having conductivity, 305 Is a conductive upper wiring, 306 is Pd, Ru, Ag, Au,
Ti, In, Cu, Cr, Fe, Zn, Sn, Ta,
Metals such as W and Pd, PdO, SnO2, In203, P
bO, oxides such as Sb203, HfB2, ZrB2, L
boride such as aB6, CeB6, YB4, GdB4B,
Carbides such as TiC, ZrC, HfC, TaC, SiC, WC, nitrides such as TiN, ZrN, HfN, Si, Ge
Semiconductors such as carbon, AgMg, NiCu, Pb, S
An electron emission portion forming thin film made of n or the like, and 307 is a conductive connection wiring.

Each electron emission portion forming thin film 307, device electrode 3
04 and the connection wiring 306, the insulating layer 303 was exposed in the peripheral portion thereof, and these made the electric field in the vicinity of the electron emission portion unstable.

[0012]

As described above, when the insulating layer is exposed on the surface of the substrate in the vicinity of the electron emitting portion, the electric field near the electron emitting portion becomes unstable, and the electron beam emitted from the electron emitting portion. Will cause instability of the shape.

It is an object of the present invention to provide an electron source substrate in which an insulating layer is not exposed on the surface of the substrate in the vicinity of the electron emitting portion of the electron source substrate, and an image forming apparatus using such an electron source substrate. .

[0014]

The electron source substrate of the present invention comprises:
The insulating layer is not exposed on the surface of the substrate around the electron emitting portion.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described.

First, the electron source substrate and the image forming apparatus according to the present invention will be described.

The cold cathode electron source used in the present invention is preferably a surface conduction electron-emitting device which has a simple structure and is easy to manufacture.

The surface conduction electron-emitting device that can be used in the present invention is basically a planar surface conduction electron-emitting device.

FIG. 5 is a schematic plan view and a sectional view showing the structure of a basic surface conduction electron-emitting device.

In FIG. 5, reference numeral 501 is a substrate, and 502 and 50.
Reference numeral 3 is a device electrode, 504 is a conductive thin film, and 505 is an electron emitting portion.

The device electrode spacing L is preferably several hundreds of μm to several hundred μm. Further, it is desirable that the voltage applied between the device electrodes is low, and since it is required to form the device with good reproducibility, the preferred device electrode interval is several μm to several tens μm.

The device electrode length W is from several μm to several hundreds μm in view of the electrode resistance value and electron emission characteristics, and the device electrode 50
The membrane pressure d of 2,503 is preferably several μm rather than several hundred A.

The conductive thin film 504 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The thickness of the conductive thin film 504 is the step coverage to the device electrodes 502 and 503 and the resistance between the device electrodes 502 and 503. The value is appropriately set depending on the value and energization forming conditions described later, but is preferably several A to several thousand A, particularly preferably 10 A.
It is 500A than A. The sheet resistance value is 10 ^{3 to} 10 ⁷ Ω / □.

The fine particle film described 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 fine particles are individually dispersed and arranged but also in a state in which fine particles are adjacent to each other or overlap each other (island). (Including the shape), and the particle size of the fine particles is from several A to several thousand A, preferably from 10 A to 200 A.

The electron emitting portion 505 is a high resistance crack formed in a part of the conductive thin film 504, and is formed by energization forming or the like. In some cases, conductive particles having a particle diameter of several A to several hundred A are contained in the crack. The conductive fine particles contain at least a part of the elements forming the conductive thin film 504.

The electron emitting portion 505 and the conductive thin film 4 in the vicinity thereof may contain carbon and carbon compounds.

An energization process called energization forming is performed. In the energization forming, electricity is applied between the element electrodes 502 and 503 from a power source (not shown) to locally destroy, deform or alter the conductive thin film 504 to form a site where the structure is changed. The part where the structure is locally changed is called an electron emission part 505. FIG. 7 shows an example of the voltage waveform of energization forming.

A pulse waveform is particularly preferable as the voltage waveform, and a voltage pulse having a constant pulse peak value is continuously applied (FIG. 6a) and a voltage pulse is applied while increasing the pulse peak value (FIG. 6b). There is. First, the case where the pulse peak value is a constant voltage (FIG. 6a) will be described.

In FIG. 6a, T1 and T2 are the pulse width and pulse interval of the voltage waveform, where T1 is 1 microsecond to 10 milliseconds, T2 is 10 microseconds to 100 milliseconds, and the peak value of the triangular wave (energizing forming). The peak voltage) is appropriately selected according to the form of the surface conduction electron-emitting device, and is applied for several seconds to several tens of minutes under an appropriate vacuum atmosphere, for example, a vacuum atmosphere of about 10 ⁻⁵ torr. The waveform applied between the electrodes of the element is not limited to a triangular wave, and a desired waveform such as a rectangular wave may be used.

T1 and T2 in FIG. 6b are the same as those in FIG. 6a, and the crest 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 element current is measured during the pulse interval T2 at a voltage that does not locally break or deform the conductive thin film, for example, a voltage of about 0.1 V, and the resistance value is measured. Is determined, and the energization forming is completed when the resistance is 1 MΩ or more.

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 process is, for example, a process of repeatedly applying a voltage pulse having a constant pulse peak value at a vacuum degree of about 10 ⁻⁴ to 10 ⁻⁵ torr, similarly to the energization forming, and is an organic substance existing in a vacuum. This is a process of depositing carbon and a carbon compound derived from a substance on a conductive thin film to remarkably change the device current If and 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 and carbon compounds are graphite (single and polycrystalline) amorphous carbon (a mixture of amorphous carbon and polycrystalline graphite).
The film thickness is preferably 500 A or less, more preferably 300 A or less. It is preferable that the electron-emitting device thus produced is placed in an atmosphere having a vacuum degree higher than the vacuum degree in the forming step and the activation step and driven. Further, in an atmosphere of higher vacuum degree, 80 ° C to 150 ° C.
It is desirable to drive after heating at ℃. The degree of vacuum higher than the degree of vacuum formed by the forming process or activation is, for example, a degree of vacuum of about 10 ⁻⁶ or more, more preferably an ultrahigh vacuum system, and a new carbon or carbon compound is added on the conductive thin film. The degree of vacuum is such that it hardly deposits on the surface. 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.

The surface conduction electron-emitting devices are arranged in a simple matrix arrangement (hereinafter referred to as a matrix-type arrangement electron source substrate) in which a pair of device electrodes of the surface conduction electron-emitting devices are connected with X-direction wiring and Y-direction wiring, respectively. can give.

The structure of the electron source constructed based on this principle will be described below with reference to FIG. 871 is an electron source substrate, 872 is an X-direction wiring, 873 is a Y-direction wiring 874 is a surface conduction electron-emitting device, and 875 is a connection.

In the figure, the substrate used for the electron source substrate 871 is the above-mentioned glass substrate or the like, and its shape is appropriately set according to the application. The m X-direction wirings 872 are DX1,
DX2, ... DXm, and the Y-direction wiring 873 is D
It consists of n wirings Y1, DY2 ... DYn.

These m X-direction wires 872 and n Y wires
The directional wirings 873 are electrically separated by an interlayer insulating layer (not shown) to form a matrix wiring (m and n are both positive integers).

An interlayer insulating layer (not shown) is formed in a desired region on a part of the substrate 871 on which the X-direction wiring 872 is formed.
The X-direction wiring 872 and the Y-direction wiring 873 are drawn out as external terminals.

Further, the device electrodes (not shown) of the surface conduction electron-emitting device 874 are electrically connected to the m X-direction wirings 872 and the n Y-direction wirings 873 by the connection wires 875.

The X-direction wiring 8 will be described later in detail.
72 is a surface conduction electron-emitting device 87 arranged in the X direction.
It is electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for scanning the four rows in accordance with the input signal. On the other hand, a modulation signal generating means (not shown) for applying a modulation signal for modulating each row of the surface conduction electron-emitting devices 874 arranged in the Y direction to the Y-direction wiring 873 according to an input signal. Is electrically connected to.

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 applied to the element and the modulation signal.

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 arrangement created as described above will be described with reference to FIGS. 8, 9 and 11. 8 is a basic configuration diagram of the image forming apparatus, FIG. 9 is a fluorescent film, and FIG. 11 is NT.
The block diagram of the drive circuit for displaying according to the SC type | mold television signal is shown, and the image forming apparatus containing the drive circuit is shown.

In FIG. 8, 971 is an electron source substrate having an electron-emitting device formed on the substrate, 981 is a rear plate to which the electron source substrate 871 is fixed, and 986 is a glass substrate 983 having a fluorescent film 984 and a metal back 985 on its inner surface. The formed face plate 982 is a support frame, and the rear plate 981, the support frame 982, and the face plate 986 are coated with frit glass or the like, and the surface of the rear plate 981, the support frame 982, and the face plate 986 is 4 in the atmosphere or nitrogen.
An envelope 988 is formed by sealing by baking at a temperature of 00 to 500 degrees for 10 minutes or more.

Reference numeral 974 in FIG. 8 corresponds to the electron emitting portion in FIG. Reference numerals 972 and 973 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the surface conduction electron-emitting device.

The envelope 988 comprises the face plate 986, the support frame 982, and the rear plate 981 as described above, and the rear plate 981 is mainly for the purpose of reinforcing the strength of the electron source substrate 971. Because it is provided,
If the electron source substrate 971 itself has sufficient strength, the separate rear plate 981 is not necessary, and the support frame 982 is directly sealed to the electron source substrate 971 and the face plate 986,
The support frame 982 may be directly sealed to the support frame 982 and the electron source substrate 971, and the face plate 986, the support frame 982, and the electron source substrate 971 may form an envelope 988. Furthermore, a face plate 986 and a rear plate 981
An envelope 988 having sufficient strength against atmospheric pressure by installing an atmospheric pressure resistant supporting member called a spacer between them.
You can also

In FIG. 9, 1092 is a phosphor. Phosphor 1
In the case of monochrome, 092 consists only of phosphor,
In the case of a color fluorescent film, it is composed of a black conductive material 1091 and a fluorescent material 1092 called a black stripe or a black matrix depending on the arrangement of the fluorescent materials. In the case of a color display, the purpose of providing the black stripes and the black matrix is to make the mixed portions between the phosphors 1092 of the three primary color phosphors black so as to make the color mixture inconspicuous and the external light in the phosphor film 984. This is to suppress a decrease in contrast due to reflection. The material for the black stripe is not limited to the commonly used material containing graphite as a main component, but is not limited to this as long as it is a material having conductivity and little light transmission and reflection.

As a method for applying the phosphor to the glass substrate 983, a precipitation method or a printing method is used regardless of monochrome or color.

A metal back 985 (FIG. 9) is usually provided on the inner surface of the fluorescent film 984 (FIG. 8). The purpose of the metal back is to improve the brightness by specularly reflecting the light to the inner surface side of the emission of the phosphor to the face plate 986 side, to act as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from the damage caused by the collision of negative ions generated inside the container. For the metal back, after the phosphor film is formed, the inner surface of the phosphor film is smoothed (usually called filming), and then Al
Can be produced by depositing by vacuum evaporation or the like.

The face plate 986 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 984 in order to further enhance the conductivity of the fluorescent film 984.

When the above-mentioned sealing is performed, in the case of color, it is necessary to make the respective color phosphors correspond to the electron-emitting devices and to perform sufficient alignment.

The envelope 988 is provided through an exhaust pipe (not shown)
The degree of vacuum is set to about 0 ^-7 torr and sealing is performed. In addition, a getter process may be performed to maintain the degree of vacuum after the envelope 988 is sealed. This is the envelope 98
A process for heating a getter arranged at a predetermined position (not shown) in the envelope 988 by a heating method such as resistance heating or high-frequency heating immediately before or after the sealing of No. 8 to form a vapor deposition film. Is. The getter usually has Ba as a main component, and due to the adsorption action of the deposited film, for example, 1 × 10 ⁻⁵
The degree of vacuum of torr or 1 × 10 ⁻⁷ torr is maintained. The steps after forming the surface conduction electron-emitting device are appropriately set.

Next, the block diagram of FIG. 11 is a schematic diagram of a drive circuit for performing television display on an image forming apparatus constructed by using an electron source having a simple matrix arrangement type substrate based on an NTSC television signal. Will be explained. 1101 is the display panel, 1102 is a scanning circuit, 1103 is a control circuit, 1104 is a shift register, 1105 is a line memory 1106 is a sync signal separation circuit, 1107 is a modulation signal generator, and Vx and Va are DC voltage sources. is there.

The functions of the respective parts will be described below. First, the display panel 1101 is connected to an external electric circuit via the terminals Dox1 to Doxm, the terminals Doyl to Doyn and the high voltage terminal Hv. Among them, the terminals Doxl to Doxm sequentially drive the electron sources provided in the display panel, that is, the surface conduction electron-emitting device groups arranged in a matrix of M rows and N columns matrix by row (N elements). A scanning signal for application is applied.

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 Dyl to Dyn. Further, from the DC voltage source Va to the high voltage terminal Hv,
For example, a DC voltage of 10 K [V] is supplied, which is an accelerating voltage for imparting sufficient energy to excite the phosphor to the electron beam output from the surface conduction electron-emitting device.

Next, the scanning circuit 1102 will be described.
The circuit is provided with M switching elements inside (schematically shown by S1 to Sm in the figure), and each switching element is an output voltage of the DC voltage source Vx or 0.
One of [V] (ground level) is selected and electrically connected to the terminals Dxl to Dxm of the display panel 1101. Each of the switching elements Sl to Sm has a control signal Tscan output from the control circuit 1103.
However, in practice, it can be constructed by combining switching elements such as FETs.

It should be noted that the DC voltage source Vx is such that the driving voltage applied to an unscanned element is equal to or lower than the electron emission threshold voltage based on the characteristics (electron emission threshold voltage) of the surface conduction electron-emitting element. It is set to output a constant voltage such that

Further, the control circuit 1103 has a function of matching the operation of each part so that an appropriate display is performed based on an image signal inputted from the outside. The synchronization signal Ts sent from the synchronization signal separation circuit 1106 described below
The control signals of Tscan, Tsft, and Tmry are generated for each unit based on the sync.

The sync signal separation circuit 1106 is a circuit for separating the sync signal component and the luminance signal component from the NTSC system television signal input from the outside, and can be constructed by using a frequency separation (filter) circuit. The sync signal separated by the sync signal separation circuit 1106 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 referred to as a DATA signal for convenience, but the signal is input to the shift register 1104.

The shift register 1104 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 1103. . (That is, the control signal Tsft may be rephrased as a shift lock of the shift register 1104.) The data of one line of the serial / parallel-converted image (corresponding to the drive data of N electron-emitting devices) is Idl. To Idn are output from the shift register 1104 as N parallel signals.

The line memory 1105 is a storage device for storing data for one line of an image for a required time, and stores the contents of Idl to Idn in accordance with the control signal Tmry sent from the control circuit 1103.
The stored contents are output as Idl to Idn and input to the modulation signal generator 1107.

The modulation signal generator 1107 is a signal source for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data Idl to Idn, and its output signal is displayed through terminals Doyl to Doyn. It is applied to the surface conduction electron-emitting device in the panel 1101.

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, electron emission has a clear threshold voltage Vth, and electron emission occurs only when a voltage equal to or higher than Vth is applied.

Further, for a voltage above the electron emission threshold value, the emission current also changes according to the change in the voltage applied to the device. The value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may be changed by changing the material, configuration, and manufacturing method of the electron emitting element. I can say things.

That is, when a pulsed voltage is applied to this element, 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, the electron beam is Is output. At that time, first, it is possible to control the intensity of the output electron beam 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, there are a voltage modulation method, a pulse width modulation method and the like. To implement the voltage modulation method, the modulation signal generator 1107 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 1107 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 1101. Although not particularly described in the above description, the shift register 1104 and the line memory 1105 may be digital signal type or analog signal type, and the point is that serial / parallel conversion and storage of image signals are performed at a predetermined speed. It should be done.

When the digital signal type is used, it is necessary to convert the output signal DATA of the sync signal separation circuit 1106 into a digital signal, which can be achieved by providing an A / D converter at the output section of 1106. Further, in connection with this, the circuit used for the modulation signal generator 1107 is slightly different depending on whether the output signal of the line memory 1105 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 1107 has
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 1107 compares the output value of the memory with the output value of the counter and the counter for counting the number of waves output from the oscillator, for example. It can be configured by using a circuit in which comparators (comparators) 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, the modulation signal generator 1107 has
For example, a well-known amplifier circuit using an operational amplifier may be used, 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 oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage to the drive voltage of the surface conduction electron-emitting device may be used if necessary. May be added.

In the image display device completed as described above, each electron-emitting device is thus provided with the external terminal Doxl of the container.
To Doxm and Doyl to Doyn to apply a voltage to emit electrons, and a high voltage is applied to the metal back or a transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam and cause the fluorescent film 84 to move. 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. , Is appropriately selected to suit the application of the image forming apparatus. Further, although the NTSC system is given as an example of the input signal, the input signal is not limited to this, and PAL, SECA
Various methods such as the M method may be used, or a TV signal (for example, a high-definition TV such as the MUSE method) including a number of scanning lines may be used.

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.

[0078]

EXAMPLES Two examples of the electron source substrate according to the present invention will be described below with reference to FIGS.

FIGS. 1 and 2 show the steps of manufacturing the electron source substrate by sectional views. The plan view and the sectional view of the electron source substrate completed in the final step, that is, the constitution of the electron source substrate of the embodiment of the present invention. It is shown.

[0080]

[Embodiment 1] A method of manufacturing an electron source substrate according to a first embodiment of the present invention will be described with reference to FIG. Step-a Cr / Cu / Cr (300A / 7000A) is formed on the cleaned soda-lime glass 101 using a vacuum deposition method and a lift-off method.
The lower wiring 102 made of / 300A) is formed at a desired position. Step-b Next, the interlayer insulating layer 103 made of SiO2 (10000A) is formed at a desired position by using a sputtering method, a photolithography method, and a dry etching method. Step-c A device electrode 104 made of Ti / Pt (50A / 500A) is formed at a desired position by using a sputtering method, a photolithography method, and a dry etching method. Step-d After that, using the lift-off method and the vacuum deposition method, Cr / A
u (300 A / 10000 A) is formed at the upper wiring 105 forming position and the connecting wiring 106 forming position. Step-e Next, a resist is arranged at the electron emitting portion forming thin film, the upper wiring, and the connection wiring forming position, and SiO2 in other portions is removed by a dry etching method. Step-f After that, organic Pd (ccp4230 manufactured by Okuno Chemical Industries Co., Ltd.) is spray-coated and baked, and an electron emission consisting of fine particles of Pd as a main element at a desired position is formed by a photolithography method and a dry etching method. Part forming thin film 1
07 is formed. The electron emitting portion forming thin film thus formed is subjected to a forming process to form an electron emitting portion, and an electron source substrate is produced.

An image forming apparatus can be manufactured by using the simple matrix arrangement type electron source substrate having the surface conduction type electron emitting device thus obtained.

Comparing the electron source substrate shown in step f (final step) of FIG. 1 with the conventional electron source substrate shown in FIG.
The insulating layer around the electron-emitting portion forming thin film of each electron-emitting device, the device electrode and the connection wiring as shown in FIG. 1 is removed, and the insulating layer is almost absent in step f of FIG. . (Note that the electron source substrate of FIG.
This corresponds to the case where step e is not included in. )

[0083]

Second Embodiment The manufacturing process of the second embodiment of the electron source substrate according to the present invention is shown in FIG. Step-a Cr / Cu / Cr (300A / 7000A) on the cleaned soda-lime glass 201 using a vacuum deposition method and a lift-off method.
The lower wiring 202 made of / 300A) is formed at a desired position. Step-b Next, the interlayer insulating layer 203 made of SiO2 (10000A) is formed at a desired position by using a sputtering method, a photolithography method, and a dry etching method. Step-c The element electrode 204 made of Ti / Pt (50A / 500A) is formed at a desired position by using a sputtering method, a photolithography method, and a dry etching method. Step-d After that, using the lift-off method and the vacuum deposition method, Cr / A
u (300 A / 10000 A) is formed at the upper wiring 205 formation position and the connection wiring 206 formation position. Step-e Subsequent formation of the electron emission portion forming thin film 207 and formation of the electron emission portion by the forming process are the same as in the first embodiment. Also in this case, the insulating layer is barely exposed in the periphery of the electron emission portion forming thin film, the device electrode, and the connection flow line, and the lower wiring can be seen.

[0084]

EFFECTS OF THE INVENTION By avoiding exposing the insulating layer around the electron emitting portion of the surface conduction electron-emitting device that constitutes the electron source substrate, the spread of the electron beam emitted from each electron source substrate can be increased. In addition, it is possible to suppress fluctuations, and it is possible to obtain a relatively fine and stable display image in an image forming apparatus using such an electron source substrate.

[Brief description of drawings]

[0085]

FIG. 1 is a diagram showing a first embodiment of an electron source substrate according to the present invention and a manufacturing process thereof.

[0086]

FIG. 2 is a diagram showing a second embodiment of an electron source substrate according to the present invention and a manufacturing process thereof.

[0087]

FIG. 3 is a configuration example of a conventional electron source substrate.

[0088]

FIG. 4 is a typical device configuration diagram.

[0089]

FIG. 5 is a schematic plan view (a) and a sectional view (b) showing the configuration of a basic surface conduction electron-emitting device of the present invention.

[0090]

FIG. 6 is an example of a voltage waveform of energization forming according to the present invention.

[0091]

FIG. 7: Electron source with simple matrix arrangement

[0092]

FIG. 8 is a schematic configuration diagram of an image forming apparatus.

[0093]

FIG. 9: Fluorescent film

[0094]

FIG. 10 is a block diagram of a drive circuit for displaying according to an NTSC television signal, and an image display device having the drive circuit.

[0095]

[Explanation of symbols]

Reference Signs List 101 blue plate glass 102 lower wiring 103 interlayer insulating layer 104 element electrode 105 upper wiring 106 connection wiring 107 electron emission portion forming film 201 blue glass glass 202 lower wiring 203 interlayer insulating layer 204 element electrode 205 upper wiring 206 connection wiring 207 electron emission portion forming thin film 301 Insulating Substrate 302 Lower Wiring 303 Interlayer Insulating Layer 304 Element Electrode 305 Upper Wiring 306 Connection Wiring 307 Electron Emitting Part Forming Thin Film 401 Substrate 402, 403, 404 Conductive Thin Film 405 Electron Emitting Part 501 Substrate 502, 503 Element Electrode 504 Conductive Thin film 505 Electron emission portion 871 Electron source substrate 872 X-direction wiring 873 Y-direction wiring 874 Surface conduction electron-emitting device 875 Connection 981 Rear plate 982 Support frame 983 Glass substrate 984 Fluorescent film 985 Metal bag 986 Face plate 987 High voltage terminal 988 Enclosure 1091 Black conductive material 1092 Fluorescent substance 1093 Glass substrate 1104 Shift register 1105 Line memory 1106 Synchronous signal separation circuit 1107 Modulation signal generator, Vx and Va, DC voltage source 1210 Electron source substrate 1211 Electronic Emitting elements 1212 Dx1 to Dx10 are common wirings 1220 for wiring the electron emitting elements 1220 Grid electrodes 1221 Holes for passing electrons 1222 Doxl, Dox2. . . Doxm outer terminal 1223 G1, connected to grid electrode 1320
G2 ,. . . Outer container terminal made of Gn 1324 Electron source substrate

Claims (2)

[Claims] 1. A plurality of surface conduction electron-emitting devices are arranged in an array on a substrate, and one of a pair of device electrodes facing each other with a thin film forming an electron-emitting portion of each of the electron-emitting devices sandwiched therebetween. Is connected to the upper wiring along the upper surface of the insulating layer on the substrate, the other element electrode is connected to the lower wiring along the lower surface of the insulating layer through the connection wiring that penetrates the insulating layer, The electron source substrate, wherein the insulating layer is not exposed on the surface of the electron source substrate around the electron emitting portion. 2. An image forming apparatus using the electron source substrate according to claim 1.