JPH08162004A - Electron emitting device, electron source, and image forming apparatus using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a surface-conduction electron-emitting device having a novel structure, which has an electron-emitting characteristic suitable as an electron source for an image forming apparatus or the like. In a surface conduction electron-emitting device in which an electron-emitting portion 2 is provided on a conductive thin film 3 that connects the device electrodes 4 and 5, a continuous linear distribution is provided in the device electrode interval so that the device is electrically conductive in a single device. It is characterized in that the resistance value of the conductive thin film 3 has a distribution. [Effect] It is possible to suppress variations in the driving voltage due to noise or the like and changes in the emission current amount due to fluctuations without causing an unnecessary increase in the element driving voltage.

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 provided with a plurality of such devices, and an image forming apparatus such as a display device and an exposure device configured by using the electron source.

[0002]

2. Description of the Related Art A surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current is passed through a conductive thin film formed on an insulating substrate in parallel with the film surface.

As a typical configuration example of the surface conduction electron-emitting device, as shown in FIG. 19, a metal oxide or the like for connecting between a pair of device electrodes 4 and 5 provided on an insulating substrate 1 is used. An example of the conductive thin film 3 is one in which the electron emitting portion 2 is formed in advance by an energization process called forming. Forming is usually performed by applying a voltage across both ends of the conductive thin film 3 to locally destroy the conductive thin film 3,
This is a process of deforming or modifying the structure to change the structure and form the electron emitting portion 2 in an electrically high resistance state. The electron emission is performed from the vicinity of the crack generated in the electron emitting portion 2 by applying a voltage to the conductive thin film 3 on which the electron emitting portion 2 is formed and flowing a current.

Since the surface conduction electron-emitting device has a simple structure and is relatively easy to manufacture, it has an advantage that many arrays can be formed over a large area. Therefore, various applications for utilizing this feature are being researched. For example, it can be used for an image forming apparatus such as a charged beam source and a display device.

Conventionally, as an example in which a large number of surface conduction electron-emitting devices are formed in an array, surface conduction electron-emitting devices are arranged in parallel and both ends (both device electrodes) of each surface conduction electron-emitting device are wired. An electron source may be an electron source in which a plurality of rows (also referred to as a common wiring) are arranged in rows (also referred to as a ladder arrangement) (JP-A-64-31332 and JP-A-1-2).
No. 83749, Japanese Patent Laid-Open No. 2-257552).

Further, particularly in the case of the display device, a surface conduction electron emission device can be used as a self-luminous display device which can be a flat panel display device similar to the display device using liquid crystal and does not require a backlight. A display device has been proposed (US Pat. No. 5,066,883) in which an electron source in which a large number of elements are arranged and a phosphor which emits visible light when irradiated with an electron beam from the electron source are combined.

[0007]

The emission current Ie and the device current If of the surface conduction electron-emitting device and the device voltage V
A typical example of the relationship with f is shown in FIG. Note that, in FIG. 6, the emission current Ie is markedly smaller than the device current If, and is therefore shown in arbitrary units. Thus, the surface conduction electron-emitting device has a certain voltage (called a threshold voltage: FIG. 6).
Electron emission is obtained from the device voltage Vf of Vth), and the emission current Ie shows a non-linear large increase with respect to the change of the device voltage Vf equal to or higher than the threshold voltage Vth.

On the other hand, when an electron source in which a plurality of surface conduction electron-emitting devices are arranged and an image forming apparatus using this electron source are manufactured, wiring resistance connecting the electron source drive circuit and the surface conduction electron-emitting device is used. The voltage applied to each element electrode may vary among a plurality of elements due to the influence of a voltage drop or the like. Further, the drive voltage may fluctuate due to noise generated inside the electron source drive circuit or noise due to electromagnetic waves received from the environment outside the electron source and the image forming apparatus.

In such a case, due to the above-mentioned electron emission characteristics of the surface conduction electron-emitting device, a slight variation in the driving voltage causes a large variation in the emission current Ie, and in the image forming apparatus, variation in formed image. / May cause flicker.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to perform more stable electron emission with respect to fluctuations in the driving voltage due to noise and the like, and not to unnecessarily increase the driving voltage. It is an object of the present invention to provide a surface conduction electron-emitting device having a novel structure and an electron source in which a plurality of surface conduction electron-emitting devices are arranged.

Another object of the present invention is to enable high-quality image formation with less variation / flicker in the formed image in an image forming apparatus using an electron source.

[0012]

Means and Actions for Solving the Problems The constitution of the present invention made to achieve the above object is as follows.

That is, the first aspect of the present invention is a surface conduction electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects a pair of device electrodes, and the conductive thin film has an electric resistance value of An electron-emitting device is characterized in that it is formed with a preset distribution.

A second aspect of the present invention is a surface conduction electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects between a pair of device electrodes, and the distance between the pair of device electrodes is small. An electron-emitting device is characterized in that it is formed with a preset distribution.

The second aspect of the present invention is further characterized in that the distance distribution between the device electrodes is several tens nm to several hundreds μ.
Including linear distribution in the range of m.

A third aspect of the present invention is an electron source characterized by comprising a plurality of the above-described first or second electron-emitting devices of the present invention on a substrate.

The third aspect of the present invention is further characterized in that the electron source has at least one or more device rows in which a plurality of electron-emitting devices are arranged, and wiring for driving each electron-emitting device is a matrix. It is also arranged that the electron source has at least one row of elements in which a plurality of electron-emitting devices are arranged, and that the wiring for driving each electron-emitting element is arranged in a ladder shape. .

Further, a fourth aspect of the present invention resides in an image forming apparatus having the electron source of the third aspect of the present invention and an image forming member for forming an image by irradiation of an electron beam emitted from the electron source.

First, the basic structure of the surface conduction electron-emitting device of the present invention will be described.

FIG. 1 is a schematic view best showing the features of the surface conduction electron-emitting device of the present invention. In the figure, 1 is a substrate, 2 is an electron emitting portion, 3 is a conductive thin film including an electron emitting portion, and 4 and 5 are device electrodes. As shown in FIG. 2, the surface conduction electron-emitting device of the present invention may have a configuration in which the device electrodes 4, 5 and the conductive thin film 3 are arranged in a vertical relationship opposite to that of the device configuration of FIG. .

As the substrate 1, for example, quartz glass, Na
Examples thereof include glass having a reduced content of impurities such as blue glass, soda lime glass, a laminated body obtained by laminating SiO ₂ on soda lime glass by a sputtering method, and ceramics such as alumina.

As the material of the device electrodes 4 and 5 facing each other,
Common conductor materials are used, such as Ni, Cr, Au,
Metal or alloy such as Mo, W, Pt, Ti, Al, Cu and Pd, and printed conductor composed of metal or metal oxide such as Pd, Ag, Au, RuO ₂ , Pd-Ag and glass. , In ₂ O ₃ —SnO _{2 and} other transparent conductors, and polysilicon and other semiconductor conductor materials.

The device electrode interval is defined by L1 and L2, and L1 and L2 have different values in order to have a distribution in the electric resistance value of the conductive thin film 3 including the electron emitting portion 2 in a single device. The values of L1 and L2 are each preferably in the range of several tens nm to several hundreds of μm, and particularly preferably several μm to depending on the voltage applied between the device electrodes 4 and 5 and the electric field strength capable of emitting electrons. It is several tens of μm.

The element electrode spacing is not limited to the linear distribution defined by L1 and L2 as shown in FIGS. 1 and 2, but is appropriately set in combination with the design of the element characteristics described later. The distribution may be discontinuous.

The device electrode length W1 is preferably several μm to several hundreds μm, and the device electrode thickness d is several tens nm to several μm in consideration of the resistance value of the electrodes and electron emission characteristics.

The conductive thin film 3 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 3 depends on the step coverage of the device electrodes 4 and 5, and the device. It is appropriately set depending on the resistance value between the electrodes 4 and 5 and the forming conditions described later. The thickness of the conductive thin film 3 is preferably several Å to several thousand Å, particularly preferably 10 Å to 500 Å, and its resistance value is 10
The sheet resistance value is ³ to 10 ⁷ Ω / □.

The fine particle film 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 shape). (Including)). In the case of a fine particle film, the particle diameter of the fine particles is preferably several Å to several thousand Å, particularly preferably 10 Å to 200 Å.

As the material for forming the conductive thin film 3, for example, Pd, Pt, Ru, Ag, Au, Ti, In, C are used.
Metals such as u, Cr, Fe, Zn, Sn, Ta, W and Pb, PdO, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O
Oxides such as ₃ HfB ₂ , ZrB ₂ , LaB ₆ , CeB
Borides such as ₆ , YB ₄ , GdB ₄ , TiC, ZrC, H
Carbides such as fC, TaC, SiC, WC, TiN, Zr
Examples thereof include nitride elements such as N and HfN, semiconductors such as Si and Ge, and carbon.

In the present invention, it is essential to have a distribution in the electric resistance value of the conductive thin film 3 including the electron emission portion 2 within a single element. Besides, the element electrode spacing is kept constant as in the conventional element shown in FIG. 19 and the film thickness of the conductive thin film 3 is changed within a single element to distribute the electric resistance value of the conductive thin film 3. May have. Further, both the element electrode spacing and the film thickness of the conductive thin film may have distribution.

A crack is included in the electron emitting portion 2, and the electron is emitted from the vicinity of the crack. The electron emission portion 2 including the crack and the crack itself are formed depending on the film thickness, film quality, material of the conductive thin film 3, the forming conditions described later, and the like. Therefore, the position and shape of the electron emitting portion 2 are not limited to the position and shape shown in FIGS. 1 and 2. In addition, depending on the manufacturing method, the entire space between the opposing device electrodes 4 and 5 may function as the electron emitting portion 2.

The cracks may have conductive fine particles having a particle diameter of several Å to several hundred Å. The conductive fine particles are the same as some or all of the elements of the material forming the conductive thin film 3. Further, the electron emitting portion 2 including a crack and the conductive thin film 3 in the vicinity thereof may contain carbon and a carbon compound.

Various methods are conceivable as a method of manufacturing the surface conduction electron-emitting device of the present invention, and the surface conduction electron-emitting device having the structure shown in FIG. 1 is taken as an example and based on the manufacturing process chart of FIG. An example will be described below. Note that steps a to c shown below correspond to (a) to (c) in FIG.

Step a: After the substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum deposition method, a sputtering method or the like, and then on the surface of the substrate 1 by a photolithography technique. Element electrodes 4 and 5 are formed on the substrate. At this time, the device electrodes 4 and 5 are formed so as to have a predesigned distribution, that is, a continuous linear distribution (L1 <L2) defined by L1 and L2 in the case of FIG.

Step b: An organic metal solution is applied on the substrate 1 provided with the device electrodes 4 and 5 and heated and baked to connect the device electrodes 4 and 5 to form a conductive thin film. . Then, the conductive thin film is patterned by lift-off, etching or the like to form the conductive thin film 3 having a predetermined pattern.

The organic metal solution is a solution of an organic compound whose main element is a metal which is a constituent material of the conductive thin film 3 described above. Here, the description has been given by using the coating method of the organic metal solution, but the present invention is not limited to this. For example, vacuum deposition method, sputtering method, chemical vapor deposition method, dispersion coating method, dipping method,
The conductive thin film can also be formed by a spinner method or the like.

Step c: Subsequently, an energization process called forming is performed. When electricity is applied between the device electrodes 4 and 5 from a power source (not shown), the electron emitting portion 2 having a changed structure is formed at the portion of the conductive thin film 3. By this energization treatment, the conductive thin film 3 is locally destroyed, deformed or altered, and the electron-emissive portion 2 is a portion whose structure is changed.

FIG. 4 shows an example of the voltage waveform of forming.

The voltage waveform is particularly preferably a pulse waveform,
There are a case where a voltage pulse whose pulse peak value is a constant voltage is continuously applied (FIG. 4A) and a case where a voltage pulse is applied while increasing the pulse peak value (FIG. 4B).

First, the case where the pulse peak value is a constant voltage will be described. In FIG. 4A, T1 and T2 are the pulse width and pulse interval of the voltage waveform, for example, T1 is 1 μsec to 10 msec, T2 is 10 μsec to 100 msec,
The peak value (peak voltage at the time of forming) is appropriately selected according to the form of the surface conduction electron-emitting device described above, and a suitable vacuum degree, for example, in a vacuum atmosphere of about 1 × 10 ⁻⁵ Torr. Apply for several seconds to several tens of minutes. The voltage waveform to be applied is not limited to the illustrated triangular wave, and a desired waveform such as a rectangular wave can be used.

Next, the case where the voltage pulse is applied while increasing the pulse peak value will be described. T1 and T2 in FIG. 4 (b) are the same as those in FIG. 4 (a), and the peak value (peak voltage during forming) is increased by, for example, about 0.1 V step, and FIG. The application is performed under an appropriate vacuum atmosphere similar to the description of 1.

In the pulse interval T2, the conductive thin film 3
(See FIGS. 1 and 2) A resistance value is obtained by measuring the device current at a voltage that does not locally break, deform, or alter the characteristics, for example, a voltage of about 0.1 V, and a resistance of 1 M ohm or more is shown. Sometimes forming ends.

The basic characteristics of the surface conduction electron-emitting device of the present invention thus obtained will be described below.

FIG. 5 is a schematic block diagram showing an example of a measurement / evaluation system for measuring the electron emission characteristics of the surface conduction electron-emitting device. First, the measurement / evaluation system will be described.

5, the same reference numerals as those in FIG. 1 indicate the same members. Further, 51 is a power supply for applying a device voltage Vf to the device, 50 is an ammeter for measuring a device current If flowing through the conductive thin film 3 between the device electrodes 4 and 5, and 54 is an electron emitting portion 2. An anode electrode for trapping the emission current Ie generated, 53 is a high-voltage power supply for applying a voltage to the anode electrode 54, and 52 is a measurement of the emission current Ie emitted from the electron emission portion 5. An ammeter, 55 is a vacuum device, and 56 is an exhaust pump.

The surface conduction electron-emitting device, the anode electrode 54 and the like are installed in a vacuum device 55.
Is equipped with necessary equipment such as a vacuum gauge (not shown),
The surface conduction electron-emitting device can be measured and evaluated under a desired vacuum.

The exhaust pump 56 is composed of a normal high vacuum system such as a turbo pump and a rotary pump, and an ultra high vacuum system such as an ion pump.
The entire vacuum device 55 and the substrate 1 of the surface conduction electron-emitting device can be heated up to about 200 ° C. by a heater (not shown).

The basic characteristics of the surface conduction electron-emitting device described below are that the voltage of the anode electrode 54 of the above-mentioned measurement evaluation system is 1 kV to 10 kV, and the distance H between the anode electrode 54 and the surface conduction electron-emitting device is H. Is normally set to 2 mm to 8 mm and the measurement is normally performed.

In order to easily understand the characteristics of the surface conduction electron-emitting device of FIG. 1, the approximate model of the surface conduction electron-emitting device of FIG. 1 is used here. As this approximate model, an element obtained by dividing the surface conduction electron-emitting device of FIG. 1 into three (hereinafter, referred to as “model element”) is shown in FIG. In FIG. 7, L3 and L5 correspond to L1 and L2 of FIG. 1, respectively, and L4 has an intermediate value between L1 and L2. Therefore,
Element electrodes of three element elements included in the model element 4,
When each of the five sets is electrically shorted, this can be considered approximately equivalent to the device shown in FIG. The surface conduction electron-emitting device of the present invention may actually be configured as such a model device and is not limited to three divisions.
You may comprise by 2 or 3 or more element elements.

The surface conduction electron-emitting device of the present invention is also shown in FIG.
As shown in FIG. 9, the element electrode interval L is constant, and the resistance value of the conductive thin film 3 does not have a particular distribution and is substantially uniform, and has the basic characteristics as shown in FIG. However, a big difference from the conventional device will be described with reference to the emission current Ie-device voltage Vf characteristic diagram shown in FIG.

In FIG. 8, the emission current-device voltage characteristics a, b, and c shown by dotted lines show the characteristics of the device elements having the device electrode intervals L3, L4, and L5 in the model device, respectively, and shown by the solid line. The given characteristics are the characteristics when the respective element electrodes of these three element elements are electrically connected, and are the sum of the characteristics a, b, and c. The characteristics indicated by the one-dot chain line and the two-dot chain line are the characteristics of the conventional element shown in FIG. still,
The alternate long and short dash line shows the characteristics of the conventional element in which the element electrode interval L is equal to L3 in the model element, the alternate long and two short dashes line represents the element electrode interval L in equal to L5 in the model element, and the other element configurations are the same as the model element.

As can be seen from FIG. 8, the model device according to the present invention has the same amount of emission current I as the two conventional devices.
rate of change of the emission current Ie with respect to a change in element voltage Vf in e (I _ope) element is obtained voltage Vf (V _{openMosix is per)} is smaller.

The reason for this will be described below.

As described above, the emission current Ie of the surface conduction electron-emitting device changes depending on the device voltage Vf.
The threshold voltage Vth at this time is substantially defined by the voltage applied to the electron emitting portion 2. The voltage substantially applied here is a net voltage obtained by removing the voltage drop in the film quality portion of the conductive thin film 3 from the device voltage Vf.

That is, when the resistance value of the conductive thin film 3 is small (that is, when the element electrode interval is as small as L3) and when it is large (that is, when the element electrode interval is as large as L5), the conductive thin film 3 is formed. Since the degree of voltage drop due to V is different (the smaller the resistance value of the conductive thin film 3 is, the smaller the voltage drop is), the voltage applied to the electron emission portion 2 is substantially different even if the device voltages Vf are equal. Therefore, the element electrode intervals are L3, L4,
As L5 becomes larger, the threshold voltage also becomes Vtha,
A larger device voltage is required to obtain the same amount of electron emission while shifting to Vthb and Vthc to the higher voltage side.

Therefore, in FIG. 8, when it is assumed that each element is driven within the emission current Ie range of I _{0 to} I _max , the range of the driving voltage of each element is the model element according to the present invention shown by the solid line. Vtha to V _max2 , Vtha to V _{max1 for} the element indicated by the one-dot chain line, and Vt for the element indicated by the two-dot chain line
hc to V _max3 . Considering the magnitude relationship between the ranges of these driving voltages, Vtha to V are naturally obtained.
_{max2> Vtha~V} is _max1, Vtha~V _max3> V
tha to V _max1 . Further, according to the experiments by the present inventors, when divided like a model element, Vtha to V
_max2 ≈ Vthc to _Vmax3 , and the element electrode intervals are continuously and linearly distributed (the number of divisions is considered to be ∞).
In the element shown in the Vtha~V _max2 = Vthc~
It has been confirmed that V _max3 is _achieved .

In this way, the conventional element indicated by the one-dot chain line is
Although the threshold voltage Vth is low, since the range of the driving voltage is small, the degree of change of the emission current Ie with respect to the change of the element voltage Vf is large, and as described above, it is unstable with respect to the fluctuation of the driving voltage due to noise or the like. The electron emission characteristics are shown.

On the other hand, the conventional element indicated by the chain double-dashed line has a wider driving voltage range and more stable electron emission characteristics, but unnecessarily increases the driving voltage.

In contrast to the above two conventional elements, the element of the present invention shown by the solid line has no increase in the threshold voltage Vth,
Moreover, since the range of the drive voltage can be widened, more stable electron emission characteristics are exhibited without an unnecessary increase in the drive voltage.

Next, three characteristic characteristics of the surface conduction electron-emitting device of the present invention with respect to the emission current Ie will be described with reference to FIG.

First of all, the surface conduction electron-emitting device is
When the element voltage Vf equal to or higher than the threshold voltage Vth is applied, the emission current Ie rapidly increases, while the threshold voltage Vth
In the following, the emission current Ie is hardly detected. That is, it is a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie has a characteristic of monotonically increasing with respect to the element voltage Vf (referred to as MI characteristic), the emission current Ie can be controlled by the element voltage Vf.

Thirdly, the emitted charges trapped in the anode electrode 54 (see FIG. 5) depend on the time for applying the device voltage Vf. That is, the amount of charges captured by the anode electrode 54 can be controlled by the time for which the device voltage Vf is applied.

The characteristic shown by the solid line in FIG. 6 is the emission current Ie.
Has an MI characteristic with respect to the element voltage Vf, and at the same time, the element current If also has an MI characteristic with respect to the element voltage Vf. However, as indicated by a broken line in FIG. 6, the element current If becomes the element voltage Vf. On the other hand, it may exhibit a voltage control type negative resistance characteristic (called a VCNR characteristic). Which characteristic is exhibited is
It depends on the manufacturing method of the device and the measurement conditions at the time of measurement. However,
Even if the device current If has a VCNR characteristic with respect to the device voltage Vf, the emission current Ie is M with respect to the device voltage Vf.
It has the I characteristic.

Due to the above characteristic characteristics of the surface conduction electron-emitting device, the amount of emitted electrons can be easily controlled according to the input signal even in an electron source or an image forming apparatus in which a plurality of devices are arranged. Therefore, it can be applied to various fields.

Next, the arrangement of the surface conduction electron-emitting devices in the electron source of the present invention will be described.

As a method of arranging the surface conduction electron-emitting devices in the electron source of the present invention, in addition to the ladder arrangement as described in the section of the prior art, n Y's are arranged on m X-direction wirings. There is an arrangement method in which directional wirings are provided via an interlayer insulating layer and an X-direction wiring and a Y-direction wiring are connected to a pair of device electrodes of the surface conduction electron-emitting device. This is hereinafter referred to as a simple matrix arrangement. First, this simple matrix arrangement will be described in detail.

According to the basic characteristics of the surface conduction electron-emitting device described above, when the applied device voltage Vf exceeds the threshold voltage Vth, the electron is generated at the peak value and pulse width of the applied pulsed voltage. The amount of release can be controlled. On the other hand, below the threshold voltage Vth, almost no electrons are emitted. Therefore, even when a large number of surface conduction electron-emitting devices are arranged, it becomes possible to apply a pulsed voltage controlled according to an input signal only by simple matrix wiring, select individual devices and drive them independently. .

The simple matrix arrangement is based on the above principle, and the structure of the electron source of the simple matrix arrangement which is an example of the electron source of the present invention will be further described with reference to FIG.

In FIG. 9, the substrate 1 is a glass plate or the like as already described, and the number and shape of the surface conduction electron-emitting devices 104 arranged on the substrate 1 are appropriately set according to the application. Is.

The m number of X-direction wirings 102 each have external terminals DX1, DX2, ... DXm, and are provided on the substrate 1
A conductive metal or the like formed on the upper surface by a vacuum deposition method, a printing method, a sputtering method, or the like. In addition, the material, so that the voltage is supplied almost evenly to the large number of surface conduction electron-emitting devices 104,
The film thickness and wiring width are set.

The n Y-direction wirings 103 each have external terminals DY1, DY2, ... DYn, and are formed similarly to the X-direction wirings 102.

These m X-direction wirings 102 and n Y-wirings
An interlayer insulating layer (not shown) is provided between the directional wirings 103 and electrically separated to form a matrix wiring. In addition, both m and n are positive integers.

The interlayer insulating layer (not shown) is SiO ₂ or the like formed by a vacuum deposition method, a printing method, a sputtering method or the like, and has a desired shape on the entire surface or a part of the substrate 1 on which the X-direction wiring 102 is formed. In particular, the film thickness, material, and manufacturing method are appropriately set so as to withstand the potential difference at the intersection of the X-direction wiring 102 and the Y-direction wiring 103. The X-direction wiring 102 and the Y-direction wiring 103 are drawn out as external terminals.

Further, the opposing device electrodes (not shown) of the surface conduction electron-emitting device 104 are m number of X-direction wirings 102.
And n Y-direction wirings 103, a vacuum deposition method, a printing method,
Connection 1 made of a conductive metal or the like formed by a sputtering method or the like
05 are electrically connected.

Here, the m X-direction wirings 102, the n Y-direction wirings 103, the connection lines 105, and the opposing element electrodes may have the same or partial constituent elements. Further, they may be different from each other, and are appropriately selected from the above-mentioned material of the device electrode and the like. The wiring to these element electrodes may be generically referred to as an element electrode when the same material as the element electrode is used. The surface conduction electron-emitting device 104 may be formed either on the substrate 1 or on an interlayer insulating layer (not shown).

Further, as will be described in detail later, a scanning signal is applied to the X-direction wiring 102 in order to scan the rows of the surface conduction electron-emitting devices 104 arranged in the X-direction according to an input signal. A scanning signal applying means (not shown) is electrically connected.

On the other hand, a modulation signal (not shown) is applied to the Y-direction wiring 103 in order to modulate each row of the surface conduction electron-emitting devices 104 arranged in the Y-direction according to an input signal. The signal applying means is electrically connected. The drive voltage applied to each surface conduction electron-emitting device 104 is supplied as a difference voltage between the scanning signal and the modulation signal applied to the surface conduction electron-emitting device.

Next, an example of the image forming apparatus of the present invention using the electron source of the present invention having the above simple matrix arrangement will be described with reference to FIGS. 10 is a basic configuration diagram of the display panel 201, and FIG. 11 is a fluorescent film 1.
14 is a view showing the display panel 20 of FIG.
1 is a block diagram showing an example of a drive circuit for performing television display in accordance with the NTSC system television signal in FIG.

In FIG. 10, 1 is a substrate of an electron source in which the surface conduction electron-emitting devices are arranged as described above, 111
Is a rear plate on which the substrate 1 is fixed, and 116 is a fluorescent film 11 which is an image forming member on the inner surface of the glass substrate 113.
4 and a metal back 115 etc.
Reference numeral 112 is a support frame. The rear plate 111, the support frame 112, and the face plate 116 are sealed by applying frit glass or the like to their joints and firing at 400 ° C. to 500 ° C. for 10 minutes or more in the air or a nitrogen atmosphere. Then, the outer envelope 118 is constructed.

In FIG. 10, 102 and 103 are a pair of device electrodes 4 and 5 of the surface conduction electron-emitting device 104 (see FIG. 1).
And the wiring in the Y direction connected to the external terminals Dx1 to Dxm and Dy1 to D, respectively.
have yn.

The envelope 118 is composed of the face plate 116, the support frame 112 and the rear plate 111 as described above. However, the rear plate 111 is provided mainly for the purpose of reinforcing the strength of the substrate 1, and when the substrate 1 itself has sufficient strength, the rear plate 1 is a separate body.
11, the support frame 112 may be directly sealed to the substrate 1, and the face plate 116, the support frame 112, and the substrate 1 may constitute the envelope 118. Further, by further installing a support body (not shown) called a spacer between the face plate 116 and the rear plate 111, it is possible to form the envelope 118 having sufficient strength against atmospheric pressure.

The fluorescent film 114 is composed of only the fluorescent material 122 in the case of monochrome, but is composed of the fluorescent material 1 in the case of color.
22 array has a black stripe (see FIG. 11).
(A)) or black matrix (Fig. 11 (b))
And the like, and a phosphor 122. The purpose of providing the black stripes and the black matrix is to make the color mixture, etc., inconspicuous by blackening the separately colored portions between the phosphors 122 of the three primary colors required for color display, and to reflect external light on the phosphor film 114. This is to suppress the decrease in contrast due to. As the material of the black conductive material 121, not only a commonly used material containing graphite as a main component, but also another material can be used as long as it is a material that is conductive and has little light transmission and reflection. .

As a method for applying the phosphor 122 to the glass substrate 113, a precipitation method or a printing method is used regardless of monochrome or color.

Further, as shown in FIG. 10, the fluorescent film 1
A metal back 115 is usually provided on the inner surface side of 14. The purpose of the metal back 115 is to allow the phosphor 122 (see FIG.
1)) to improve brightness by specularly reflecting the light to the inner surface side to the face plate 116 side, and to act as an electrode for applying an electron beam accelerating voltage from the high voltage terminal Hv. This is to protect the phosphor 122 from damage due to collision of negative ions generated in the envelope 118. The metal back 115 can be manufactured by performing smoothing processing (usually called filming) on the inner surface of the fluorescent film 114 after manufacturing the fluorescent film 114, and then depositing Al by vacuum vapor deposition or the like.

The face plate 116 may be provided with a transparent electrode (not shown) on the outer surface side of the fluorescent film 114 in order to further enhance the conductivity of the fluorescent film 114.

In the case of the above-mentioned sealing, in the case of a color, the phosphors 122 of the respective colors have to correspond to the surface conduction electron-emitting devices 104, so that it is necessary to perform sufficient alignment.

The inside of the envelope 118 is sealed through a vacuum degree of about 10 ^-6 Torr through an exhaust pipe (not shown).
Further, the getter process may be performed immediately before or after the envelope 118 is sealed. This is to heat a getter (not shown) arranged at a predetermined position in the envelope 118 by a heating method such as resistance heating or high frequency heating.
This is a process of forming a vapor deposition film. The getter usually contains Ba or the like as a main component.
^{This is} for maintaining a vacuum degree of ^-5 to 10 ^-7 Torr.

The above-mentioned forming process for the electron source is performed by the device electrode of each surface conduction electron-emitting device 104 through the X-direction wiring 102 and the Y-direction wiring 103 immediately before or after sealing the envelope 118. It can be performed by energizing between 4 and 5.

The display panel 201 described above is, for example, as shown in FIG.
It can be driven by a driving circuit as shown in FIG.
In FIG. 12, 201 is the display panel,
202 is a scanning circuit, 203 is a control circuit, 204 is a shift register, 205 is a line memory, 206 is a sync signal separation circuit, 207 is a modulation signal generator, and Vx and Va are DC voltage sources.

As shown in FIG. 12, the display panel 20
1 is connected to an external electric circuit via the external terminals Dx1 to Dxm, the external terminals Dy1 to Dyn, and the high-voltage terminal Hv. Of these, the external terminals Dx1 to Dx
In xm, a surface conduction electron-emitting device provided in the display panel 201, that is, a group of surface conduction electron-emitting devices arranged in a matrix of m rows and n columns is sequentially arranged for each row (n elements). A scanning signal for driving is applied.

On the other hand, the external terminals Dy1 to Dyn are connected to
A modulation signal for controlling the output electron beam of each element in one row selected by the scanning signal is applied. Further, the high voltage terminal Hv is, for example, 10 kV from the DC voltage source Va.
DC voltage is supplied. This is an accelerating voltage for giving enough energy to excite the phosphor to the electron beam output from the surface conduction electron-emitting device.

The scanning circuit 202 has therein m switching elements (schematically shown by S1 to Sm in FIG. 12).
Each of the switching elements S1 to Sm selects either the output voltage of the DC voltage source Vx or 0V (ground level) and is electrically connected to the external terminals Dx1 to Dxm of the display panel 201. It is a thing. Each of the switching elements S1 to Sm includes a control circuit 203.
It operates on the basis of the control signal Tscan output from the device, and in fact, it can be easily configured by combining elements having a switching function such as an FET.

The DC voltage source Vx in this example has a threshold drive voltage applied to the surface-conduction electron-emitting devices which are not scanned, based on the characteristics (threshold voltage) of the surface-conduction electron-emitting devices. It is set to output a constant voltage that is less than or equal to the value voltage.

The control circuit 203 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 synchronization signal Tsyn sent from the synchronization signal separation circuit 206 described below
Based on c, Tscan, Tsft, and Tmry control signals are generated for each unit.

The synchronizing signal separating circuit 206 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal inputted from the outside, and as is well known, a frequency separating (filtering) ) Using a circuit,
It can be easily constructed. Sync signal separation circuit 206
The synchronizing signal separated by means of a vertical synchronizing signal and a horizontal synchronizing signal are also well known. Here, for convenience of explanation, it is shown as Tsync. On the other hand, the luminance signal component of the image separated from the television signal is referred to as D for convenience.
This is shown as an ATA signal. This DATA signal is input to the shift register 204.

The shift register 204 is for serial / parallel conversion of the DATA signal serially input in time series for each line of the image, and based on the control signal Tsft sent from the control circuit 203. Operate. The control signal Tsft is supplied to the shift register 20.
In other words, it may be said that the shift clock is four. Also,
One line of serial / parallel converted image (corresponding to driving data for n elements of the surface conduction electron-emitting device)
Data is output from the shift register 204 as n parallel signals Id1 to Idn.

The line memory 205 is a storage device for storing data for one line of an 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 203. The stored contents are output as I′d1 to I′dn and input to the modulation signal generator 207.

The modulation signal generator 207 is a signal line for appropriately driving and modulating each of the surface conduction electron-emitting devices according to each of the image data I'd1 to I'dn.
The output signal is applied to the surface conduction electron-emitting device in the display panel 201 through the external terminals Dy1 to Dyn.

As described above, the surface conduction electron-emitting device has a clear threshold voltage for electron emission, and electron emission occurs only when a voltage exceeding the threshold voltage is applied. For voltages exceeding the threshold voltage,
The emission current also changes according to the change in the voltage applied to the surface conduction electron-emitting device. The value of the threshold voltage and the degree of change of the emission current with respect to the applied voltage may be changed by changing a part of the material, structure, and manufacturing method of the surface conduction electron-emitting device. Can be said.

That is, when a pulsed voltage is applied to the surface conduction electron-emitting device, no electron emission occurs even if a voltage below the threshold voltage is applied, but a voltage exceeding the threshold voltage is applied. If it does, electron emission occurs. At that time, firstly, it is possible to control the intensity of the output electron beam by changing the peak value of the voltage pulse. Secondly, it is possible to control the total amount of charges of the output electron beam by changing the width of the voltage pulse.

Therefore, as a method of modulating the surface conduction electron-emitting device according to the input signal, there are a voltage modulation method and a pulse width modulation method. In the case of performing the voltage modulation method, the modulation signal generator 207 uses a voltage modulation method circuit that generates a voltage pulse of a constant length, but can appropriately modulate the pulse peak value according to the input data. In the case of performing the pulse width modulation method, the modulation signal generator 207 generates a voltage pulse having a constant peak value, but a circuit of the pulse width modulation method capable of appropriately modulating the pulse width according to the input data is used. To use.

The shift register 204 and the line memory 20
5 may be of a digital signal type or an analog signal type as long as it can perform serial / parallel conversion and storage of an image signal 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 206 into a digital signal. This can be done by providing an A / D converter at the output of the sync signal separation circuit 206.

In connection with this, the line memory 20
Depending on whether the output signal of 5 is a digital signal or an analog signal,
The circuit provided in the modulation signal generator 207 is slightly different.

That is, in the case of the voltage modulation method using a digital signal, for the modulation signal generator 207, 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 a pulse width modulation method using a digital signal, the modulation signal generator 207, for example, a high-speed oscillator and a counter (counter) that counts the number of waves output by the oscillator, and the output value of the counter and the output value of the memory. It can be easily configured by using a circuit in which comparators for comparison are combined. Further, if necessary, an amplifier for voltage-amplifying the pulse-width-modulated modulation signal output from the comparator to the drive voltage of the surface conduction electron-emitting device may be added.

On the other hand, in the case of the voltage modulation method using analog signals, the modulation signal generator 207 may be, for example, an amplifier circuit using a well-known operational amplifier or the like, and a level shift circuit or the like may be added if necessary. May be. Further, in the case of the pulse width modulation method using an analog signal, for example, a well-known voltage controlled oscillation circuit (VCO) may be used, and the voltage is amplified to the drive voltage of the surface conduction electron-emitting device as necessary. May be added.

The image forming apparatus of the present invention having the display panel 201 and the driving circuit as described above has the external terminals Dx1 to Dx1.
By applying a voltage from Dxm and Dy1 to Dyn, an electron can be emitted from any electron-emitting device 104, and a high voltage is applied to the metal back 115 or a transparent electrode (not shown) through the high-voltage terminal Hv. Bee
A television display can be performed according to an NTSC television signal by excitation / light emission caused by accelerating the beam and causing the accelerated electron beam to collide with the fluorescent film 114.

The above-described structure is a schematic structure necessary for obtaining the image forming apparatus of the present invention used for display or the like, and the detailed parts such as the material of each member are limited to the above contents. However, it is appropriately selected so as to suit the purpose of the image forming apparatus. Further, although the NTSC system has been taken as an example of the input signal, the image forming apparatus of the present invention is not limited to this, and other systems such as PAL and SECAM systems may be used, and more scanning lines than these may be used. The TV signal may be a high-definition TV system such as the MUSE system.

Next, an example of the above-mentioned ladder-type electron source and an image forming apparatus of the present invention using the electron source will be described with reference to FIGS. 13 and 14.

In FIG. 13, 1 is a substrate, 104 is a surface conduction electron-emitting device, and 304 is a common wiring for connecting the surface conduction electron-emitting device 104. Ten common wirings are provided, each having external terminals D1 to D10. are doing. A plurality of surface conduction electron-emitting devices 104 are arranged in parallel on the substrate 1. This is called an element row. A plurality of these element rows are arranged to form an electron source.

It is possible to drive each element row independently by applying an appropriate drive voltage between the common wiring 304 of each element row (for example, the common wiring 304 of the external terminals D1 and D2). That is, a voltage exceeding the threshold voltage may be applied to the element row where the electron beam is desired to be emitted, and a voltage lower than the threshold voltage may be applied to the element row where the electron beam is not desired to be emitted. The application of such a driving voltage is performed on the common wirings D2 to D9 located between the element rows by the common wirings 304 adjacent to each other, that is, the external terminals D adjacent to each other.
The common wiring 304 of 2 and D3, D4 and D5, D6 and D7, and D8 and D9 can also be formed as an integrated same wiring.

FIG. 14 is a diagram showing the structure of a display panel 301 having the above-mentioned ladder-type electron sources.

In FIG. 14, 302 is a grid electrode,
Reference numeral 303 is an opening through which electrons pass, D1 to Dm are external terminals for applying a voltage to each surface conduction electron-emitting device, and G1 to Gn are terminals connected to the grid electrode 302. Further, the common wiring 304 between each element row is formed on the substrate 1 as an integrated single wiring.

Note that, in FIG. 14, the same reference numerals as those in FIG. 10 indicate the same members, and a big difference from the display panel 201 using the electron source of the simple matrix arrangement shown in FIG. The point is that the grid electrode 302 is provided between 116.

The grid electrode 302 is provided between the substrate 1 and the face plate 116 as described above. The grid electrode 302 is capable of modulating the electron beam emitted from the surface conduction electron-emitting device 104, and the electron beam is applied to the stripe-shaped electrodes provided orthogonally to the device rows in the ladder type arrangement. To pass
A circular opening 303 is provided for each of the surface conduction electron-emitting devices 104.

The shape and arrangement position of the grid electrode 302 are
The openings 303 are not necessarily shown in FIG. 14, and a large number of openings 303 may be provided in a mesh shape, and the grid electrode 302 may be provided, for example, in the surface conduction electron-emitting device 10.
It may be provided around 4 or in the vicinity thereof.

The external terminals D1 to Dm and G1 to Gn are connected to a drive circuit (not shown). Then, in synchronization with the sequential driving (scanning) of the element rows one column at a time, a modulation signal for one line of the image is applied to the columns of the grid electrode 302, so that each electron beam is applied to the fluorescent film 114. The irradiation can be controlled and the image can be displayed line by line.

As described above, the image forming apparatus of the present invention is
An image formation that can be obtained by using the electron source of the present invention in either a simple matrix arrangement or a trapezoidal arrangement and is suitable not only as a display device for the television broadcast described above but also as a display device for a video conference system, a computer, or the like. The device is obtained. Further, it can also be used as an exposure device of an optical printer constituted by a photosensitive drum and the like.

[0119]

EXAMPLES The present invention will be further described with reference to the following examples.

Example 1 In this example, an example in which the surface conduction electron-emitting device shown in FIG. 1 was manufactured will be described. FIG.
FIG. 1A is a plan view of a surface conduction electron-emitting device.
(B) has shown sectional drawing. In the figure, W1 is the width of the element electrode, W2 is the width of the conductive thin film 3, L1 and L2 are the intervals between the element electrodes 4 and 5, and d is the thickness of the element electrode.

A method of manufacturing the surface conduction electron-emitting device of this embodiment will be described with reference to FIG. The following steps a to c correspond to (a) to (c) in FIG.

Step a: On a substrate 1 in which a 0.5 μm-thick silicon oxide film is formed on a cleaned soda-lime glass by a sputtering method, a pattern in which a gap between element electrodes should be L1 to L2 is formed by a photoresist (RD- 2000N-41 ・
Made by Hitachi Chemical Co., Ltd.), and the thickness is 5n by the vacuum deposition method.
m of Ti and 100 nm of Ni were sequentially deposited. The photoresist pattern is dissolved in an organic solvent, the Ni / Ti deposition film is lifted off, and the device electrode spacing L1 is 2 μm, L2.
Of 5 μm and a width W1 of 300 μm were formed.

Step b: Device electrodes 4 and 5 formed in step a
After depositing a Cr film with a film thickness of 50 nm by vacuum vapor deposition on the entire surface of the substrate including, and further applying a photoresist on the entire surface, the length of the element electrode gap and its vicinity are not less than the gap between the element electrodes, and the width W2 By using a mask (not shown) having openings, patterning, development, and etching of Cr in the openings are performed to form the device electrode gaps and the device electrodes 4, 5
A part of was exposed to produce a Cr mask having a width W2. Note that W2 was 100 μm. Organic Pd on it
(Ccp4230 / Okuno Pharmaceutical Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 10 minutes. Then, etch Cr with an acid etchant,
The conductive thin film 3 was formed by lifting off. The conductive thin film 3 formed of fine particles having Pd as a main element has a thickness of about 100Å and a sheet resistance value of 2 × 10.
It was ⁴ Ω / □. Incidentally, the fine particle film described here is a film in which a plurality of fine particles are aggregated as described above, and as a fine structure thereof, not only the fine particles are individually dispersed and arranged, but also the fine particles are adjacent to each other or overlap each other. Membrane in the open state (including islands).

Step c: Next, the substrate 1 on which the element electrodes 4 and 5 and the conductive thin film 3 are formed is placed in the vacuum device 55 of the measurement evaluation system of FIG. After the inside of the vacuum device 55 is set to 2 × 10 ⁻⁵ Torr, a voltage is applied between the element electrodes 4 and 5 by a power source 51 for applying the element voltage Vf to perform a forming process, and the electron emitting portion 2 is Formed. The voltage waveform shown in FIG. 4B was used for the forming process.

In this embodiment, T1 in FIG. 4B is set to 1 m.
Seconds, T2 was set to 10 msec, and the crest value (peak voltage) of the voltage pulse was increased in 0.1 V steps to perform the forming process. Also, during the forming process, T
A resistance measuring pulse of 0.1 V was inserted between the two to measure the resistance. The forming process was ended when the measured value by the resistance measurement pulse became about 1 MΩ or more, and at the same time, the application of the voltage to the element was ended. The forming voltage at this time was about 5.5V.

Further, as a comparative element, a conventional element in which the element electrode spacings L1 and L2 are both 2 μm and the element electrode spacing is constant was manufactured by the same material and manufacturing method as described above.

The electron emission characteristics of the surface conduction electron-emitting device manufactured as described above were measured using the above-described measurement evaluation system of FIG. The measurement conditions are the anode electrode 5
4 and the surface conduction electron-emitting device at a distance H of 4 mm.
The potential of the electrode 54 was set to 1 kV, and the degree of vacuum in the vacuum device 55 at the time of measuring electron emission characteristics was set to about 1 × 10 ^-6 Torr.

As a result, the device of the present invention of this embodiment exhibits the emission current-device voltage characteristics as shown by the solid line in FIG. 8, and the conventional device for comparison is shown by the chain line in FIG. The emission current-device voltage characteristics are shown as above. The threshold voltage Vth of the device of this example and the conventional device for comparison were both about 10V.

When each element was driven to emit electrons, the driving voltage V _{ope at} which the emission current Ie was 1.0 μA was 16 V for the element of this example and 14 V for the conventional element for comparison. It was The change amount ΔIe of the emission current Ie with respect to the device voltage Vf at each drive voltage V _ope is 0.9 μA / V in the comparative device, whereas it is 0.5 μA / V in the device of the present embodiment. Met.

As described above, since the surface conduction electron-emitting device of the present invention manufactured in this embodiment has the characteristic that the amount of emitted electrons changes little with respect to the device voltage Vf, there are variations and fluctuations in the driving voltage. It is less susceptible to the influence of, and stable electron emission can be performed.

[Embodiment 2] In this embodiment, an electron source as shown in FIG. 9 in which a large number of the surface conduction electron-emitting devices of the present invention as shown in FIG. 1 are arranged in a simple matrix is used. An example of manufacturing the image forming apparatus as shown in FIG. 10 will be described.

A plan view of a part of the electron source is shown in FIG. 16 is a sectional view taken along the line AA ′ in the figure. However, the same reference numerals in FIG. 9, FIG. 10, FIG. 15 and FIG. 16 indicate the same members.

Here, 1 is a substrate, 102 is an X-direction wiring (also called lower wiring), 103 is a Y-direction wiring (also called upper wiring), 3 is a conductive thin film, 4 and 5 are element electrodes, 401
Is an interlayer insulating layer, and 402 is a contact hole for electrically connecting the device electrode 4 and the lower wiring 102.

First, a method of manufacturing an electron source will be specifically described in the order of steps with reference to FIG. The following steps a to
h corresponds to (a) to (h) in FIG.

Step a: Cr having a thickness of 5 nm and a thickness of 6 by vacuum deposition on a substrate 1 in which a silicon oxide film having a thickness of 0.5 μm is formed on a cleaned soda-lime glass by a sputtering method.
After sequentially stacking Au of 00 nm, a photoresist (AZ
(1370 Hoechst) is spin coated by a spinner and baked, and then a photomask image is exposed and developed to form a resist pattern of the lower wiring 102, and the Au / Cr deposited film is wet-etched to obtain a desired pattern. Lower wiring 1
02 was formed.

Step b: Next, an interlayer insulating layer 401 made of a silicon oxide film having a thickness of 1.0 μm was deposited by the RF sputtering method.

Step c: A photoresist pattern for forming a contact hole 402 is formed on the silicon oxide film deposited in step b, and this is used as a mask for the interlayer insulating layer 40.
1 was etched to form a contact hole 402. The etching is performed by RIE using CF ₄ and H ₂ gas (R
The active Ion Etching method was used.

Step d: After that, a pattern to form the device electrodes 4 and 5 and the gaps L1 to L2 between the device electrodes is formed by a photoresist (RD-2000N-41 manufactured by Hitachi Chemical Co., Ltd.), and a thickness is formed by a vacuum deposition method. 5 nm Ti, thickness 100
nm of Ni was sequentially deposited. The photoresist pattern is dissolved in an organic solvent and the Ni / Ti deposited film is lifted off. The device electrode spacing L1 is 3 μm, L2 is 5 μm, and the width W1 is 30.
The device electrodes 4 and 5 of 0 μm were formed.

Process e: Upper wiring 10 on the device electrodes 4 and 5
After forming the photoresist pattern of No. 3, Ti with a thickness of 5 nm and Au with a thickness of 500 nm were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form the upper wiring 103 of a desired shape. .

Step f: Using a mask (not shown) for forming a conductive thin film having a gap between the device electrodes and an opening in the vicinity thereof, a Cr film 403 having a film thickness of 100 nm is deposited and patterned by vacuum vapor deposition on this mask, and then a mask is formed. Organic P
d (ccp-4230 manufactured by Okuno Chemical Industries Co., Ltd.) was spin-coated with a spinner and heated and baked at 300 ° C. for 10 minutes. The thickness of the conductive thin film 3 formed of fine particles of Pd as the main element thus formed is 10 nm,
The sheet resistance value was 5 × 10 ⁴ Ω / □.

Step g: The Cr film 403 and the conductive thin film 3 after firing were etched with an acid etchant to obtain a conductive thin film 3 having a desired pattern.

Step h: A resist was applied on the entire surface, exposed using a mask and developed to remove the resist only from the contact hole 402 portion. After that, by vacuum evaporation, Ti with a thickness of 5 nm and Au with a thickness of 500 nm are sequentially deposited,
Contact holes 402 were filled by removing unnecessary portions by lift-off.

Through the above steps, the lower wiring 10 is formed on the substrate 1.
2, interlayer insulating layer 401, upper wiring 103, device electrode 4,
5, the conductive thin film 3 and the like were formed to obtain an unformed electron source.

Next, an image forming apparatus was manufactured using the unformed electron source manufactured as described above. The manufacturing procedure will be described below with reference to FIGS.

First, the substrate 1 of the electron source is mounted on the rear plate 11
After being fixed to 1, the face plate 116 (formed by forming a fluorescent film 114, which is an image forming member, and a metal back 115 on the inner surface of the glass substrate 113) is formed 5 mm above the substrate 1. Arranged via the support frame 112, the face plate 116, the support frame 112, the rear plate 1
Apply frit glass to the joint of 11 and
It was sealed by baking at 0 ° C. for 10 minutes. Further, the frit glass was also used to fix the substrate 1 to the rear plate 111.

Fluorescent film 114 which is an image forming member
In the case of monochrome, it is composed of only the phosphor, but in this embodiment, the phosphor has a stripe shape (see FIG. 11A).
And the black stripes are first formed by the black conductive material 121, and the phosphors 1 of the respective colors are formed in the gaps by the slurry method.
22 was applied to produce a fluorescent film 114. Black conductive material 1
As 21, a commonly used material containing graphite as a main component was used.

A metal back 115 is provided on the inner surface side of the fluorescent film 114. The metal back 115 is the fluorescent film 1.
After producing 14, the inner surface of the fluorescent film 114 is smoothed (usually called filming), and then A
1 was vacuum-deposited.

The face plate 116 may be provided with a transparent electrode on the outer surface side of the fluorescent film 114 in order to further enhance the conductivity of the fluorescent film 114, but in this embodiment, only the metal back 115 is used. It was omitted because sufficient conductivity was obtained.

When performing the above-mentioned sealing, in the case of a color, since the phosphors 122 of the respective colors and the electron-emitting devices 104 have to correspond to each other, a sufficient alignment is performed.

Thereafter, the envelope 1 is passed through an exhaust pipe (not shown).
After the inside of 18 was evacuated to about 10 ⁻⁵ Torr, the forming voltage similar to that of the first embodiment was applied between the device electrodes 4 and 5 of each surface conduction electron-emitting device 104 through the terminals Dx1 to Dxm and Dy1 to Dyn outside the container. Was applied to form the electron emitting portion 2. The electron emission portion 2 formed in this way
Had a state in which fine particles containing a palladium element as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 3.0 nm.

Next, the inside of the envelope 118 is set to 10 ^-6.5 Torr.
The envelope 118 was sealed by evacuating to a degree of vacuum and heating an exhaust pipe (not shown) by heating with a gas burner.
Finally, in order to maintain the degree of vacuum after sealing, a getter process was performed by a high frequency heating method. The getter was mainly composed of Ba.

A display panel 201 (see FIG. 10) constructed by using electron sources arranged in a simple matrix as described above.
At the external terminals Dx1 to Dxm and Dy1 to Dyn, a scanning signal and a modulation signal are applied to the surface conduction electron-emitting device 104 by signal generating means (not shown) to emit electrons, and the high voltage terminal Hv is applied.
A high voltage of several kV or more is applied to the metal back 115 through the electron beam to accelerate the electron beam and collide with the fluorescent film 114.
An image was displayed by exciting and emitting light. as a result,
All the surface conduction electron-emitting devices 10 of the electron source of this embodiment.
Sample No. 4 was hardly affected by fluctuations in driving voltage and fluctuations, and stable electron emission was performed, so that it was possible to display an extremely good image with less fluctuations in brightness and flicker.

[Third Embodiment] FIG. 18 shows a display panel (display panel) 201 (see FIG. 10) of the second embodiment.
It is a figure which shows an example of the image display apparatus of this invention comprised so that the image information provided from various image information sources, such as television broadcasting, can be displayed.

In the figure, 201 is a display panel, 100
1 is a display panel drive circuit, 1002 is a display controller, 1003 is a multiplexer, 10
Reference numeral 04 is a decoder, 1005 is an input / output interface circuit, 1006 is a CPU, 1007 is an image generation circuit, 10
08, 1009 and 1010 are image memory interface circuits, 1011 are image input interface circuits,
Reference numerals 1012 and 1013 are TV signal receiving circuits and 1014 is an input unit.

When the display device receives a signal including both video information and audio information, such as a television signal, it naturally reproduces audio at the same time as displaying video. Descriptions of circuits, speakers, etc. relating to reception, separation, reproduction, processing, and storage of audio information that are not directly related to the features of the invention will be omitted.

Each section will be described below along the flow of the image signal.

First, the TV signal receiving circuit 1013 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication.

The TV signal system to be received is not particularly limited, and examples thereof include NTSC system, PAL system and SE.
Various methods such as a CAM method may be used. Further, a TV signal including a larger number of scanning lines than these, for example, a so-called high-definition TV such as the MUSE system is suitable for taking advantage of the display panel 201 suitable for a large area and a large number of pixels. It is a signal source.

T received by the TV signal receiving circuit 1013
The V signal is output to the decoder 1004.

The image TV signal receiving circuit 1012 is a circuit for receiving a TV image signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. Similar to the TV signal receiving circuit 1013, the system of the TV signal to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 1004.

Image input interface circuit 1011
Is a circuit for capturing an image signal supplied from an image input device such as a TV camera or an image reading scanner, and the captured image signal is output to the decoder 1004.

Image memory interface circuit 1010
Is a circuit for capturing an image signal stored in a video tape recorder (hereinafter abbreviated as VTR), and the captured image signal is output to the decoder 1004.

Image memory interface circuit 1009
Is a circuit for capturing the image signal stored in the video disc.
It is output to 04.

Image memory-interface circuit 100
Reference numeral 8 denotes a circuit for capturing an image signal from a device that stores still image data, such as a so-called still image disc. The captured still image data is decoded by a decoder 1004.
Is output to

The input / output interface circuit 1005 is
It is a circuit for connecting the display device to an external computer, a computer network, or an output device such as a printer. It is of course possible to input / output image data and character / graphic information, and in some cases, input / output control signals and numerical data between the CPU 1006 of the display device and the outside.

The image generation circuit 1007 receives image data, character / graphic information, or CPU 1006 input from the outside via the input / output interface circuit 1005.
It is a circuit for generating display image data based on image data and character / graphic information output from the output. Inside this circuit, for example, a rewritable memory for accumulating image data and character / graphic information, a read-only memory that stores image patterns corresponding to character codes,
The circuits necessary for image generation, such as a processor for image processing, are incorporated.

The display image data generated by this circuit is output to the decoder 1004, but in some cases, it can be output to an external computer network or printer via the input / output interface circuit 1005.

The CPU 1006 mainly performs operations related to operation control of the display device and generation, selection and editing of a display image.

For example, a control signal is output to the multiplexer 1003 to appropriately select or combine image signals to be displayed on the display panel 201. At that time, a control signal is generated to the display panel controller 1002 according to the image signal to be displayed, and the screen display frequency, the scanning method (for example, interlaced or non-interlaced), the number of scanning lines in one screen, etc. are displayed. The operation of the device is controlled appropriately. In addition, image data and character / graphic information are directly output to the image generation circuit 1007,
Alternatively, the external computer or memory is accessed through the input / output interface circuit 1005 to input image data or character / graphic information.

The CPU 1006 may, of course, be involved in work for other purposes. For example, it may be directly related to a function of generating and processing information, such as a personal computer or a word processor. Alternatively, as described above, the computer may be connected to an external computer network via the input / output interface circuit 1005, and work such as numerical calculation may be performed in cooperation with an external device.

The input unit 1014 is used by the user to input commands, programs, data, etc. to the CPU 1006. For example, in addition to a keyboard and a mouse,
It is possible to use various input devices such as a joystick, a bar code reader, and a voice recognition device.

The decoder 1004 converts various image signals input from the above 1007 to 1013 into three primary color signals,
Alternatively, it is a circuit for inverse conversion into a luminance signal, an I signal, and a Q signal. In addition, as shown by a dotted line in FIG.
It is desirable that 004 has an image memory inside. This is to handle a television signal that requires an image memory for reverse conversion, such as the MUSE method.

The provision of the image memory makes it easy to display a still image. Alternatively, the image processing circuit 1007 and the CPU 1006 cooperate with each other to obtain an advantage of facilitating image processing and editing such as image thinning, interpolation, enlargement, reduction, and composition.

The multiplexer 1003 is the CPU 10
The display image is appropriately selected on the basis of the control signal input from 06. That is, the multiplexer 1003 selects a desired image signal from the inversely converted image signals input from the decoder 1004 and outputs it to the drive circuit 1001. In that case, by switching and selecting image signals within one screen display time, it is possible to divide one screen into a plurality of areas and display different images depending on the areas, as in a so-called multi-screen television. .

Display panel controller 1002
Is a circuit for controlling the operation of the drive circuit 1001 based on a control signal input from the CPU 1006.

As the elements related to the basic operation of the display panel 201, for example, the display panel 201
A signal for controlling the operation sequence of the driving power source (not shown) is output to the driving circuit 1001. As a signal relating to the driving method of the display panel 201, for example, a signal for controlling a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 1001. In some cases, the drive circuit 10 outputs control signals relating to image quality adjustment such as brightness, contrast, color tone, and sharpness of a display image.
It may be output to 01.

The drive circuit 1001 is a circuit for generating a drive signal to be applied to the display panel 201, based on the image signal input from the multiplexer 1003 and the control signal input from the display panel controller 1002. It works.

The functions of the respective parts have been described above. With the configuration illustrated in FIG. 18, the display panel 2 displays image information input from various image information sources in this display device.
01 can be displayed. That is, various image signals such as television broadcasts are transmitted to the decoder 1004.
After being inversely converted in, the signal is appropriately selected in the multiplexer 1003 and input to the driving circuit 1001. On the other hand, the display controller 1002 generates a control signal for controlling the operation of the drive circuit 1001 according to the image signal to be displayed. The drive circuit 1001 applies a drive signal to the display panel 201 based on the image signal and the control signal. As a result, the image is displayed on the display panel 201. These series of operations are centrally controlled by the CPU 1006.

In this image forming apparatus, the image memory built in the decoder 1004 and the image generating circuit 100 are included.
7 and the CPU 1006 are involved not only to display one selected from a plurality of image information but also to enlarge, reduce, rotate, move, edge emphasize, thin out, and interpolate the displayed image information. It is also possible to perform image processing such as color conversion and aspect ratio conversion of images, and image editing such as combining, erasing, connecting, replacing, and fitting. Although not particularly mentioned in the description of the present embodiment, a dedicated circuit for performing processing and editing on audio information may be provided as in the above-mentioned image processing and image editing.

Therefore, the present image forming apparatus is a display device for television broadcasting, a terminal device for a video conference, an image editing device for handling still images and moving images, a computer terminal device, an office terminal device such as a word processor,
It is possible to combine the functions of a game console etc. with one unit,
It has an extremely wide range of applications for industrial or consumer use.

Note that FIG. 18 merely shows an example of the configuration in the case of an image forming apparatus using a display panel in which the electron-emitting devices are electron beam sources, and the image forming apparatus of the present invention is not limited thereto. It goes without saying that it is not limited.

For example, among the constituent elements shown in FIG. 18, circuits relating to functions not necessary for the purpose of use may be omitted.
On the contrary, the constituent elements may be added depending on the purpose of use. For example, when the image forming apparatus is applied as a videophone, it is preferable to add a television camera, a voice microphone, an illuminator, a transmission / reception circuit including a modem, and the like to the constituent elements.

In the present image forming apparatus, since the display panel 201 according to the present invention can be easily thinned, the depth of the display apparatus can be reduced. In addition, since it is easy to make a large screen, has high brightness, and has excellent viewing angle characteristics, it is possible to display a highly realistic image with high power and good visibility.

[0184]

As described above, the present invention has the following effects.

1) The resistance value of the conductive thin film which becomes a film for electron emission of the surface conduction electron-emitting device is made to be a single device by providing a predetermined distribution in the device electrode interval or the film thickness of the conductive thin film. It is possible to reduce the degree of change of the emission current amount with respect to the change of the drive voltage without causing an unnecessary increase of the drive voltage by changing the value within the range, and to reduce the emission current amount due to the variation and fluctuation of the drive voltage. It has become possible to suppress unplanned fluctuations.

2) Especially in a large-area electron source in which a large number of surface conduction electron-emitting devices are arrayed and formed, it is mixed in the drive voltage variation due to wiring resistance and the drive voltage without an unnecessary increase in power consumption. The influence of the generated noise can be reduced, and uniform and stable electron emission becomes possible.

3) In particular, in a large-screen image forming apparatus using the above-mentioned electron source, it becomes possible to form a high-quality image with less variation / flicker in the formed image.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a surface conduction electron-emitting device of the present invention.

FIG. 2 is a diagram showing another configuration example of the surface conduction electron-emitting device of the present invention.

FIG. 3 is a diagram illustrating an example of a method of manufacturing the surface conduction electron-emitting device of FIG.

FIG. 4 is an example of a voltage waveform used in forming processing.

FIG. 5 is a schematic diagram of a measurement evaluation system for measuring electron emission characteristics of a surface conduction electron-emitting device.

FIG. 6 is a diagram showing a typical example of a relationship between an emission current Ie and a device current If and a device voltage Vf of a surface conduction electron-emitting device.

FIG. 7 is a diagram showing a model device used for explaining electron emission characteristics of the surface conduction electron-emitting device of FIG.

FIG. 8 is a diagram for explaining a difference in emission current-device voltage characteristic between the surface conduction electron-emitting device of the present invention and the conventional surface conduction electron-emitting device.

FIG. 9 is a schematic diagram of an electron source having a simple matrix arrangement.

FIG. 10 is a partial cutaway perspective view showing a schematic configuration of a display panel including an electron source having a simple matrix arrangement.

FIG. 11 is a diagram showing a configuration example of a fluorescent film used in a display panel.

FIG. 12 is a block diagram showing an example of a drive circuit of an image forming apparatus that displays an image according to an NTSC television signal.

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

FIG. 14 is a partially cutaway perspective view showing a schematic configuration of a display panel including a trapezoidal arrangement of electron sources.

FIG. 15 is a partial plan view of an electron source having a simple matrix arrangement shown in a second embodiment.

16 is a partial cross-sectional view of the electron source of FIG.

17 is a diagram for explaining a manufacturing process of the electron source of FIG.

FIG. 18 is a block diagram of the image forming apparatus according to the third embodiment.

FIG. 19 is a configuration diagram of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 Electron emission part 3 Conductive thin film 4,5 Element electrode 50 Ammeter for measuring the device current If flowing through the electroconductive thin film 51 Power supply for applying a device voltage Vf to an electron emission device 52 Electron emission part Ammeter 53 for measuring emission current Ie emitted from 2 High voltage power source for applying voltage to anode electrode 54 Anode electrode 55 for trapping electrons emitted from electron emission unit 55 Vacuum device 56 Exhaust Pump 102 X-direction Wiring 103 Y-direction Wiring 104 Surface Conduction Electron Emitting Element 105 Wiring 111 Rear Plate 112 Support Frame 113 Glass Substrate 114 Fluorescent Film 115 Metal Back 116 Face Plate Hv High Voltage Terminal 118 Envelope 121 Black conductive material 122 Phosphor 201 Display panel 202 Scanning circuit 203 Control circuit 204 Shift Register 205 Line memory 206 Synchronous signal separation circuit 207 Modulation signal generator Va DC voltage source Vx DC voltage source 301 Display panel 302 Grid electrode 303 Electron passage opening 304 Common wiring for wiring electron-emitting device 104 401 Interlayer insulating layer 402 contact hole 403 Cr film 1001 display panel 201 drive circuit 1002 display controller 1003 multiplexer 1004 decoder 1005 input / output interface circuit 1006 CPU 1007 image generation circuit 1008, 1009, 1010 image memory interface circuit 1011 image input interface circuit 1012, 1013 TV signal Receiver circuit 1014 Input section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masato Yamanobe 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (7)

[Claims] 1. A surface conduction electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects between a pair of device electrodes, wherein the conductive thin film has a preset distribution of electric resistance. An electron-emitting device characterized by being formed. 2. A surface conduction electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects between a pair of device electrodes, wherein the pair of device electrodes has a distribution in which the distance between them is set in advance. An electron-emitting device characterized by being formed. 3. The distance distribution between the device electrodes is several tens nm.
3. The electron-emitting device according to claim 2, wherein the electron-emitting devices are linearly distributed in the range from 1 to several hundred μm. 4. An electron source comprising a plurality of electron-emitting devices according to claim 1 on a substrate. 5. The electron source has at least one row of elements in which a plurality of electron-emitting devices are arranged, and wirings for driving the respective electron-emitting elements are arranged in a matrix. Item 4. The electron source according to item 4. 6. The electron source has at least one device row in which a plurality of electron-emitting devices are arranged, and wirings for driving each electron-emitting device are arranged in a ladder shape. The electron source according to claim 4. 7. An image forming apparatus, comprising: the electron source according to claim 4; and an image forming member that forms an image by irradiation with an electron beam emitted from the electron source.