JPH08180795A - Surface conduction electron emitting element, electron source, image forming apparatus, and manufacture thereof - Google Patents

Abstract

PURPOSE: To uniformalize electron emitting properties of each element in an electron source for which a plurality of surface conduction electron emitting elements are used. CONSTITUTION: Element electrodes 4, 5 are formed on an insulating substrate 1, a first layer 3a made of PdO is deposited on them, a crevice 31 is formed by electric application treatment, and then a second layer 3b made of W is deposited and at the same time a crevice is formed in the crevice 31 by electric application treatment in the same way to form an electron emitting part 2. Consequently, the current value necessary for forming can be lowered and an element substrate at the time of forming can be prevented from being damaged and at the same time uniform and high electron emitting properties can be obtained.

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 using a plurality of such devices, an image forming apparatus such as a display device and an exposure device using the same, and a manufacturing method thereof.

[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 example of the structure of the surface conduction electron-emitting device, a conductive thin film such as a metal oxide which connects between a pair of device electrodes provided on an insulating substrate is referred to as forming in advance. The thing which formed the electron emission part by the electricity supply process is mentioned. Forming is usually performed by applying a voltage to both ends of the conductive thin film, and the structure is changed by locally destroying, deforming or degrading the conductive thin film, and the electron emitting portion in an electrically high resistance state is formed. Is a process for forming. The electron emission is performed from the vicinity of the crack generated in the electron emitting portion by applying a voltage to the conductive thin film in which the electron emitting portion is formed and flowing a current.

Since the electron-emitting device has a simple structure and is easy to manufacture, it has an advantage that many electron-emitting devices can be arrayed 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 display device.

Conventionally, as an example in which a large number of surface conduction electron-emitting devices are arranged and formed, the electron-emitting devices are arranged in parallel and both ends (both device electrodes) of each electron-emitting device are wired (also called common wiring). ), An electron source in which a large number of rows connected to each other (also referred to as a ladder arrangement) is provided (Japanese Patent Laid-Open Nos. 1-33132, 1-283749, and 1-257552). Further, particularly in the case of a display device, a large number of surface conduction electron-emitting devices can be used as a self-luminous display device that can be a flat panel display device similar to a 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 arranged electron source is combined with a phosphor that emits visible light when irradiated with an electron beam from the electron source.

In order to obtain a high-quality and high-definition image on a large screen in the display device using the surface conduction electron-emitting device, the number of rows and columns of the electron-emitting device is several hundreds to several thousands, respectively. It is necessary to arrange a large number of electron-emitting devices. Therefore, it is desired that each electron-emitting device has uniform electric characteristics and is easy to control.

[0007]

In the above-mentioned forming, by applying a voltage to the conductive thin film, usually continuous cracks are formed and the resistance is increased. However, depending on the conditions such as the material, if there are variations such as the thickness of the conductive thin film and the contact resistance with the element electrode, the width of the crack formed may vary greatly depending on the location.
If the width of the crack becomes larger than a certain level, electron emission cannot be performed, and as a result, the characteristics of the device become significantly lower than the characteristics that should be originally obtained. Such variations in the width of cracks are likely to occur when a simple process is used without performing special control during forming. Therefore, ideally, electrical control should be performed in response to subtle variations in the thickness of the conductive thin film for each element during forming so that cracks with a uniform narrow width are formed, or the film of the conductive thin film should be formed. It is necessary to use a film forming method that strictly suppresses variations in thickness and contact resistance with the device electrodes. However, the former is difficult to carry out as an actual production process, and the latter may increase the production cost.

If a conductive thin film is formed of a high melting point material, the durability of the device is improved, but if the conductive thin film of a high melting point material is thick, the forming step is completed. The value of the forming current, which is the maximum value of the element current required for this, becomes large, which causes a problem in the manufacturing method in an electron source having a plurality of elements.

Further, in the case where an electron source having a large number of elements, for example, an XY matrix, is subjected to the forming processing collectively for each line, the wiring resistance becomes larger than the resistance of the individual elements before forming when the number of elements in one line increases. The voltage applied to each element may vary depending on the position of the element due to the voltage drop caused by the wiring resistance, and the characteristics of the element at a specific position may be lower than those of other elements.

Further, due to the parasitic resistance of the conductive thin film,
There is a problem that the amount of electron emission varies depending on the distance from the power source.

As described above, the surface conduction electron-emitting device, the electron source using a plurality of such devices, and the image forming apparatus do not use special electrical control means and are inexpensive devices.
There has been a demand for a method capable of forming a uniform electron emitting portion in a conductive thin film, and further, a method for forming a large number of devices having uniform characteristics without being affected by wiring resistance.

[0012]

The invention according to claims 1 to 3 is a surface conduction electron-emitting device, wherein a conductive thin film is composed of upper and lower two layers, and a second layer is formed in a crack of the first layer. Is characterized in that cracks are formed.

The fourth and fifth aspects are an electron source formed by forming a plurality of the electron-emitting devices, and the sixth and seventh aspects are image forming apparatuses using the electron source.

Further, claims 8 to 11 are inventions of these manufacturing methods.

The present invention will be described in detail below.

The surface conduction electron-emitting device of the present invention includes a flat type and a vertical type, and any electron-emitting device can be used in the present invention. First, the basic structure of the planar electron-emitting device will be described.

FIGS. 1A and 1B are views showing the basic structure of a flat surface conduction electron-emitting device.

In FIG. 1, 1 is a substrate, 2 is an electron emitting portion,
Reference numeral 3 is a conductive thin film, and 4 and 5 are device electrodes.

The substrate 1 is, for example, quartz glass or 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.

The material of the opposing device electrodes 4 and 5 is as follows:
Common conductor materials are used, such as Ni, Cr, Au,
Metals or alloys such as Mo, W, Pt, Ti, Al, Cu, Pd and Pd, Ag, Au, RuO ₂ , Pd-Ag
A printed conductor composed of a metal or a metal oxide and glass, a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor conductor material such as polysilicon are appropriately selected.

The element electrode interval L, the element electrode length W, the shape of the conductive thin film 3 and the like are designed according to the applied form.

The device electrode interval L is preferably several hundred Å to several hundred μm, and more preferably several μm to several depending on the voltage applied between the device electrodes 4 and 5 and the electric field strength capable of emitting electrons. It is 10 μm.

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

In the present invention, the conductive thin film 3 is composed of at least two layers of the first layer 3a and the second layer 3b, which are formed of different materials. It is particularly preferable that both the first layer 3a and the second layer 3b are fine particle films composed of fine particles in order to obtain good electron emission characteristics. The thickness of the first layer 3a is set to the device electrodes 4, 5 Step coverage, device electrodes 4, 5
It is appropriately selected depending on the resistance value between them and the forming conditions described later, and is preferably several Å to several thousand Å, particularly preferably 10 Å to 500 Å, and the resistance value is 10 ³ to 1
The sheet resistance value is 0 ⁷ Ω / □. The film thickness of the second layer 3b is smaller than that of the first layer, and is set appropriately according to the forming conditions described later, preferably several Å to several hundred Å, particularly preferably 10 Å to 50 Å, and a resistance value. The sheet resistance value of 10 ³ to 10 ⁷ Ω / □ is preferable as in the first layer 3 a.

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

In the present invention, the constituent material of the second layer 3b is selected from the above materials so as to have a higher melting point than that of the first layer. For example, Pd is used for the first layer 3a, and Pt, Ru, W, etc., which have a higher melting point than Pd, are selected as the material for the second layer 3b. The melting point of the thin film, particularly the fine particle film, is lower than the general melting point of the material.

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.

The electron emitting portion 2 is a conductive thin film 3 consisting of two layers.
It is a high resistance crack formed in a part of the
After forming a and forming a high resistance crack, the second layer 3b is laminated by an appropriate method, and a high resistance crack is further formed in the second layer 3b. Therefore, the vicinity of the final high-resistance crack is mainly made of the material of the second layer, but the crack is formed depending on the film thickness of the conductive thin film 3, the film quality, the material, the forming conditions described later, and the like. . Further, the crack may have conductive 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.

Next, the basic structure of the vertical surface conduction electron-emitting device will be described.

FIG. 2 is a view showing the basic structure of a vertical electron-emitting device, in which 21 is a step forming member, and others are shown in FIG.
The same reference numerals as in the above denote the same members.

The substrate 1, the electron emitting portion 2, the conductive thin film 3 and the device electrodes 4 and 5 are made of the same material as that of the above-mentioned flat type electron emitting device.

The step forming member 21 is formed by, for example, a vacuum vapor deposition method,
It is made of an insulating material such as SiO ₂ attached by a printing method, a sputtering method or the like. The film thickness of the step forming member 21 corresponds to the device electrode distance L (see FIG. 1) of the planar electron-emitting device described above. It is set according to the applied voltage and the electric field strength that can emit electrons, but preferably several hundred Å ~
It is several tens of μm, and particularly preferably several hundred Å to several μm.

In the following description, of the above-mentioned planar type electron-emitting device and vertical type electron-emitting device, the planar type is taken as an example, but instead of the planar type electron-emitting device, a vertical type electron-emitting device is used. Good.

Various methods can be considered as a method of manufacturing the surface conduction electron-emitting device, and one example thereof will be described with reference to FIG. In FIG. 3, the same reference numerals as those in FIG. 1 denote the same members.

1) 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 a device is formed on the surface of the substrate 1 by a photolithography technique. The electrodes 4 and 5 are formed (FIG. 3A).

2) On the substrate 1 provided with the device electrodes 4 and 5,
By applying the organometallic solution of the first layer and leaving it to stand,
The organic metal thin film is formed by connecting the device electrodes 4 and 5 with each other. The organic metal solution is a solution of an organic compound whose main element is a metal that is a constituent material of the conductive thin film 3 described above. Then, the organic metal thin film is heated and baked to form the first layer 3a of the conductive thin film which is patterned by lift-off, etching or the like (FIG. 3B). In addition, although the description has been given here by using the coating method of the organic metal solution, the present invention is not limited to this, and for example, a vacuum deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like can be used. A film can also be formed.

3) Subsequently, an energization process called forming is performed. When a power supply (not shown) is applied between the device electrodes 4 and 5, a crack 31 is formed in the first layer 3a (see FIG. 3).
(C)).

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

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

First, the case where the pulse peak value is a constant voltage will be described with reference to FIG.

In FIG. 4A, T ₁ and T ₂ are the pulse width and pulse interval of the voltage waveform, for example, T ₁ is 1 μm.
sec to 10 msec, T ₂ 10 μsec to 100 m
sec, the peak value (peak voltage during forming) is appropriately selected according to the form of the electron-emitting device described above, and a suitable vacuum degree, for example, several seconds to several tens of minutes in a vacuum atmosphere of about 10 ⁻⁵ torr. Apply. 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 of applying a voltage pulse while increasing the pulse crest value will be described with reference to FIG.

T ₁ and T ₂ in FIG. 4B are shown in FIG.
Similar to (a), the crest value (peak voltage during forming) is increased by, for example, about 0.1 V step,
Application is performed in an appropriate vacuum atmosphere similar to the description of FIG.

Incidentally, in this case, the forming process is terminated by locally destroying the first layer 3a during the pulse interval T ₂ .
Voltage that does not cause deformation or alteration, for example 0.1V
The element current is measured at a voltage of about the same to obtain the resistance value, and the forming is terminated when the resistance value is, for example, 1 MΩ or more.

4) The device metal electrodes 4 and 5, the first layer 3a having the cracks 31 and the substrate 1 are coated with the second layer of the organometallic solution, heated and baked, and patterned to give the same effect as the first layer 3a. , The second layer 3b is formed (FIG. 3D). Here again, the method for forming the second layer 3b is not limited to the coating method, as is the case with the first layer 3a. If the resistance of the second layer is sufficiently large, patterning by lift-off, etching or the like may be omitted.

5) Similar to step 3), the second layer 3b is subjected to a forming treatment to form a crack similar to the first layer 3a, thereby forming the electron emitting portion 2 (FIG. 3 (e)).

6) Next, it is preferable to perform an activation process on the element which has completed the forming process.

The activation step is, for example, 10 ^-4 to 10 ^-5 t.
As with the description in the forming step, it means a process of repeating the application of pulses with a pulse peak value of a constant voltage at a degree of vacuum of about orr, which is used to remove carbon and carbon compounds from an organic substance existing in a vacuum atmosphere. By depositing on the emission part 2 (see FIGS. 1 and 2), the state of the device current and the emission current can be remarkably improved. It is effective to perform this activation step while measuring the device current and the emission current, for example, and to end it when the emission current is saturated, because it is effective. The pulse peak value in the activation step is preferably the peak value of the driving voltage.

The carbon and the carbon compound are graphite (both single crystal and polycrystal) and amorphous carbon (amorphous carbon and a mixture thereof with polycrystal graphite). The deposited film thickness is preferably 500 Å or less, more preferably 300 Å or less.

7) More preferably, the electron-emitting device thus manufactured is operated and driven in a vacuum atmosphere having a vacuum degree higher than the vacuum degree in the forming step and the activation step. In addition, more preferably, operation is performed after heating at 80 ° C. to 150 ° C. in a vacuum atmosphere having a higher degree of vacuum.

The vacuum atmosphere having a higher degree of vacuum than that of the forming step and the activation treatment is, for example, about 10 ^−6.
A vacuum degree having a vacuum degree of not less than torr, more preferably an ultra-high vacuum system, and a vacuum degree at which carbon and a carbon compound are not newly deposited.

By the step 7), further deposition of carbon and carbon compounds is suppressed, and the device current and the emission current are stabilized.

The basic characteristics of the surface conduction electron-emitting device 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, this 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 V _f to the device, 50 is an ammeter for measuring a device current I _f flowing through the conductive thin film 3 between the device electrodes 4 and 5, and 54 is an electron emitting portion. An anode electrode for capturing the emitted emission current I _e , 53 a high voltage power source for applying a voltage to the anode electrode 54, 52 an ammeter for measuring the emission current I _e , 55 a vacuum device, 56 Is an exhaust pump.

The electron-emitting device, the anode electrode 54, etc. are installed in a vacuum device 55, and this vacuum device 55 is equipped with necessary equipment such as a vacuum system (not shown) so that the electron-emitting device can be operated under a desired vacuum. It is possible to measure and evaluate.

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.
Further, the entire vacuum device 55 and the substrate 1 of the electron-emitting device are
It can be heated up to about 200 ° C by a heater. In addition, this measurement and evaluation system is configured such that the display panel and the inside thereof are configured as the vacuum device 55 and the inside thereof at the stage of assembling the display panel (see 201 in FIG. 8) to be described later, so that the above-described forming process It can be applied to measurement evaluation and treatment in the chemical conversion step and the subsequent steps described later.

The basic characteristics of the surface conduction electron-emitting device described below were performed by setting the voltage of the anode electrode 54 of the measurement and evaluation system to 1 kV to 10 kV and setting the distance H between the anode electrode 54 and the electron-emitting device to 2 to 8 mm. It is based on measurement.

First, the emission current I _e and the device current I _f ,
FIG. 6 shows a typical example of the relationship with the device voltage V _f . still,
In FIG. 6, the emission current I _e is markedly smaller than the device current I _f, and therefore is shown in arbitrary units. Incidentally, the vertical axis,
The horizontal axis is a linear scale.

As is apparent from FIG. 6, the electron-emitting device has the following three characteristic characteristics with respect to the emission current I _e .

First, the electron-emitting device has a device voltage V _f equal to or higher than a certain voltage (referred to as a threshold voltage: V _{th in} FIG. 6).
When the voltage is applied, the emission current I _e rapidly increases, while at the threshold voltage V _th or less, the emission current I _e is hardly detected.
That is, it is a non-linear element having a clear threshold voltage V _th with respect to the emission current I _e .

Secondly, since the emission current I _e has a characteristic of monotonically increasing with respect to the device voltage V _f (referred to as MI characteristic), the emission current I _e can be controlled by the device voltage V _f .

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

The emission current I _e is MI with respect to the device voltage V _f .
At the same time having a characteristic, it may have a MI characteristic with respect to the device current I _f also the device voltage V _f. An example of the characteristics of such a surface conduction electron-emitting device is the characteristics shown by the solid line in FIG. On the other hand, as indicated by a broken line in FIG. 6, the device current _If is different from the device voltage _Vf in the voltage-controlled negative resistance characteristic (VCN).
R characteristics). Which characteristic is exhibited depends on the manufacturing method of the electron-emitting device and the measurement conditions at the time of measurement. However, in FIG. 6, the characteristics represented by the solid line and the broken line are shown on a scale different from each other in the vertical and horizontal axes. Further, the device current _If is VCN with respect to the device voltage _Vf .
Even in the electron-emitting device having the R characteristic, the emission current I _e has the MI characteristic with respect to the device voltage V _f .

When the morphology of cracks in the conventional surface conduction electron-emitting device is observed with a scanning electron microscope, there are a narrow crack portion and a wide crack portion. It is considered that the local electron emission amount and current amount change variously depending on the crack width, and it is considered that the narrow portion of the crack probably contributes to the electron emission. The cause of such distribution of crack width is considered as follows.

The applied current is distributed according to the film thickness of the conductive thin film, and cracks start to be generated when the temperature rise due to the Joule heat exceeds a certain threshold value. Once cracks start to form, a large amount of power is concentrated at the ends of the cracks, and a wide crack is formed all at once. And stop. When the voltage is increased, the next process starts again, and by repeating this process, a wide crack location and a narrow crack location alternately appear.

In the surface conduction electron-emitting device of the present invention, the current is not concentrated at the place where the crack of the conductive thin film of the first layer is wide, because the resistance of the second layer is increased due to the re-application. . Rather, the electric current concentrates on a small crack in the first layer and the crack starts to propagate from here. Further, in the present invention, since the material having a higher melting point than that of the first layer is used for the second layer, the crack of the formed second layer is narrower than the crack width of the first layer, and the crack of the first layer is The portion formed inside and contributing to electron emission is increased, and the electron emission characteristic is improved.

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 Ys 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 respectively connected to a pair of device electrodes of an 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, the emitted electrons in the electron-emitting device arranged in the simple matrix are:
It can be controlled by the peak value and pulse width of the pulsed voltage applied between the opposing element electrodes. On the other hand, almost no electrons are emitted below the threshold voltage. Therefore, even when a large number of electron-emitting devices are arranged, if the pulsed voltage is appropriately applied to each device, the electron-emitting device can be selected according to the input signal, and the electron emission amount can be controlled. Individual electron-emitting devices can be selected and driven independently by only matrix wiring.

The simple matrix arrangement is based on such a principle, and the structure of the electron source having 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. 7, 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 set appropriately according to the application. is there.

The m wirings in the X direction 102 have external terminals D _x1 , D _x2 , ..., D _xm , respectively.
It is a conductive metal or the like formed by a vacuum deposition method, a printing method, a sputtering method, or the like. Further, the material, the film thickness, and the wiring width are set so that the voltage is supplied to the many electron-emitting devices 104 substantially evenly.

The n Y-direction wirings 103 have external terminals D _y1 , D _y2 , ..., D _yn , respectively.
It is created in the same way as 02.

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.

Further, opposing device electrodes (not shown) of the electron-emitting device 104 are formed by m X-direction wirings 102 and n Y-direction wirings 103 by a vacuum evaporation method, a printing method, a sputtering method or the like. They are electrically connected by a connecting wire 105 made of a conductive metal or the like.

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

Further, as will be described later in detail, the electron-emitting devices 104 arranged in the X direction are formed on the X-direction wiring 102.
In order to scan the row according to the input signal, a scanning signal applying means (not shown) for applying the scanning signal is electrically connected.

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

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. Note that FIG. 8 is a basic configuration diagram of the display panel 201, FIG. 9 is a diagram showing the fluorescent film 114, and FIG. 10 is the display panel 201 of FIG.
It is a block diagram showing an example of a drive circuit for performing a television display according to a television signal of a TSC system.

In FIG. 8, 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 to which the substrate 1 is fixed, and 116 is a glass substrate 1.
A face plate having a fluorescent film 114, a metal back 115 and the like formed on the inner surface of 13 and a support frame 112. Frit glass or the like is applied to the rear plate 111, the support frame 112, and the face plate 116, and the atmosphere or nitrogen is used. Then, the envelope 118 is configured by sealing by baking at 400 to 500 ° C. for 10 minutes or more.

In FIG. 8, 2 corresponds to the electron emitting portion in FIG. 102 and 103 are electron-emitting devices 104.
X-direction wiring and Y connected to the pair of device electrodes 4, 5
The directional wiring has external terminals D _{x1 to} D _xm and D _{y1 to} D _yn , respectively.

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 separate rear plate 111 is not necessary, and the rear plate 111 is directly supported on the substrate 1. 112 is sealed,
The envelope 118 may be composed of the face plate 116, the support frame 112, and the substrate 1. 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.

In the case of monochrome, the fluorescent film 114 is composed of only the phosphor 122, but in the case of the color fluorescent film 114, depending on the arrangement of the phosphors 122, a black stripe (FIG. 9A) or a black matrix (FIG. 9) is used. 9
(B)) Black conductive material 121 and phosphor 122, etc.
Composed of and. The purpose of providing the black stripes and the black matrix is to make the color mixture, etc., inconspicuous by making the coating portions between the phosphors 122 of the three primary colors necessary for color display black, 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 may be used as long as it is conductive and has little light transmission and reflection. it can.

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.
A metal back 115 is usually provided on the inner surface side of 4.
The purpose of the metal back 115 is to improve the brightness by specularly reflecting the light to the inner surface side of the light emission of the phosphor 122 (see FIG. 9) to the glass substrate 113 side, and to apply an electron beam acceleration voltage. Acting as an electrode,
For example, protection of the phosphor 122 from damage due to collision of negative ions generated in the envelope 118. Metal back 1
15 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 evaporation 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.

At the time of performing the above-mentioned sealing, in the case of color, the phosphors 122 of the respective colors have to correspond to the 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 1 × 10 ⁻⁷ torr through an exhaust pipe (not shown). Also, the getter process may be performed immediately before or after the envelope 118 is sealed. This is a process of heating a getter (not shown) arranged at a predetermined position in the envelope 118 to form a vapor deposition film. The getter usually has Ba or the like as a main component, and is for maintaining a vacuum degree of, for example, 1 × 10 ⁻⁵ to 1 × 10 ⁻⁷ torr by the adsorption action of the vapor deposition film.

The above-described forming process and the subsequent manufacturing steps of the electron-emitting device are usually performed immediately before or after the encapsulation of the envelope 118, and the contents thereof are as described above.

The above-mentioned display panel 201 is shown in FIG.
It can be driven by a driving circuit as shown in FIG.
In FIG. 10, 201 is a 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, 2
Reference numeral 07 is a modulation signal generator, and V _x and V _a are DC voltage sources.

As shown in FIG. 10, the display panel 20
1 is connected to an external electric circuit via the external terminals D _{x1 to} D _xm , the external terminals D _{y1 to} D _yn, and the high voltage terminal Hv.
Of these, the external terminals D _{x1 to} D _xm are connected to the display panel 201.
A scanning signal is applied for sequentially driving the electron-emitting devices provided therein, that is, the electron-emitting devices arranged in a matrix of m rows and n columns, one row at a time (n elements).

On the other hand, a modulation signal for controlling the output electron beam of each electron-emitting device of one row selected by the scanning signal is applied to the external terminals D _{y1 to} D _yn . Also,
The high-voltage terminal Hv receives, for example, 10 k from the DC voltage source V _a.
A DC voltage of V is supplied. This is an acceleration voltage for giving enough energy to excite the phosphor to the electron beam output from the electron-emitting device.

The scanning circuit 202 is provided with m switching elements (schematically shown by S _{1 to} S _m in FIG. 10) inside, and each switching element S _{1 to} S _m is a DC voltage source V _x. Output voltage or 0 V (ground level) is selected and electrically connected to the external terminals D _{x1 to} D _{xm of} the display panel 201. Each of the switching elements S _{1 to} S _m operates based on the control signal T _scan output from the control circuit 203, and in practice, is easily configured by combining elements having a switching function such as FETs. It is possible.

The DC voltage source V _x in this example is based on the characteristics (threshold voltage) of the surface conduction electron-emitting device, and the drive voltage applied to the unscanned electron-emitting device is the threshold voltage. It is set to output a constant voltage as follows.

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. Based on a synchronization signal T _sync sent from a synchronization signal separation circuit 206 described below, control signals T _scan , T _sft, and T _mry are generated for each unit.

The sync signal separation circuit 206 is a circuit for separating a sync signal component and a luminance signal component from an NTSC television signal input from the outside, and as is well known, a frequency separation (filter). If you use a circuit,
It can be easily constructed. Sync signal separation circuit 206
As is well known, the sync signal separated by is composed of a vertical sync signal and a horizontal sync signal. here,
For convenience of explanation, it is shown as T _sync . Meanwhile, the luminance signal component of the image separated from the television signal is DAT for convenience.
A signal is illustrated. This DATA signal is input to the shift register 204.

The shift register 204 is for converting the DATA signal serially input in time series into serial / parallel conversion for each line of the image, and based on the control signal T _sft sent from the control circuit 203. Works. In other words, the control signal T _sft is the shift clock of the shift register 204. Further, the data of one line of the serial / parallel-converted image (corresponding to the driving data of n elements of the electron-emitting device) is I
Examples n parallel signals _d1 ~I _dn shift register 2
It is output from 04.

The line memory 205 is a storage device for storing data for one line of an image for a required time,
The contents of I _{d1 to} I _dn are appropriately stored according to the control signal T _mry sent from the control circuit 203. The stored content is I
_The signals are output as _{d'1 to} I _d'n and input to the modulation signal generator 207.

The modulation signal generator 207 is a signal source for appropriately driving and modulating each of the electron-emitting devices in accordance with each of the image data I _{d'1 to} I _d'n , and its output signal is
It is applied to the electron-emitting devices in the display panel 201 through the terminals D _{y1 to} D _yn .

As described above, the 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. Further, when the voltage exceeds the threshold voltage, the emission current also changes according to the change in the voltage applied to the 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 change by changing the material, configuration, and manufacturing method of the electron-emitting device, but the following can be said in any case.

That is, when a pulsed voltage is applied to the electron-emitting device, for example, when a voltage below the threshold voltage is applied, no electron emission occurs, but when a voltage exceeding the threshold voltage is applied. Produces electron emission. 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. Second
In addition, 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 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 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 an amplifier circuit using, for example, a well-known operational amplifier, and a level shift circuit or the like may be added if necessary. May be. Further, in the case of a pulse width modulation method using an analog signal, for example, a well-known voltage control type oscillation circuit (VCO) may be used, and an amplifier for amplifying the voltage up to the driving voltage of the electron-emitting device may be used if necessary. May be added.

In the image forming apparatus of the present invention having the display panel 201 and the driving circuit as described above, by applying a voltage from the terminals D _{x1 to} D _xm and D _{y1 to} D _yn , electrons are emitted from necessary electron-emitting devices. Excitation caused by applying a high voltage to the metal back 115 or a transparent electrode (not shown) through the high voltage terminal Hv to accelerate the electron beam, and causing the accelerated electron beam to collide with the fluorescent film 114. -By light emission, television display can be performed according to an NTSC television signal.

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 described as the input signal, the image forming apparatus according to 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. It is also possible to use a high-definition TV system such as a TV signal 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. 11 and 12.

In FIG. 11, reference numeral 1 is a substrate, 104 is a surface conduction electron-emitting device, and 304 is a common wiring for connecting the electron-emitting device 104. Ten common wirings are provided, each having external terminals D _{1 to} D ₁₀ . ing.

A plurality of 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.

Each element row can be independently driven 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 D ₁ and D ₂ ). 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. Application of the driving voltage, the common wiring D ₂ to D ₉ located at each element rows, the external terminals D ₂ and D ₃ adjacent common wiring 304, i.e. each phase adjacent each phase, D ₄ and D ₅ , D ₆ and D ₇ , and D ₈ and D ₉ common wiring 304 can be integrated into the same wiring.

FIG. 11 is a diagram showing the structure of a display panel 301 provided with the above-mentioned ladder-type electron source, which is another example of the electron source of the present invention.

In FIG. 11, 302 is a grid electrode, 303 is an opening through which electrons pass, D _{1 to} D _m are external terminals for applying a voltage to each electron-emitting device, and G _{1 to} G _n are grid electrodes 302. Is an external terminal connected to. Further, the common wiring 304 between each element row is formed on the substrate 1 as an integrated single wiring.

In FIG. 12, the same reference numerals as those in FIG. 8 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 electron-emitting device 104, and is for passing the electron beam through the stripe-shaped electrode provided orthogonal to the device row in the ladder type arrangement. In addition, one circular opening 303 is provided for each electron-emitting device 104.

The shape and position of the grid electrode 302 are
It does not necessarily have to be the one shown in FIG. 12, and a large number of openings 303 may be provided in a mesh shape, and the grid electrode 302 may be provided, for example, around or near the electron-emitting device 104.

The external terminals D _{1 to} D _m and G _{1 to} G _n are connected to a drive circuit (not shown). Then, by applying a modulation signal for one image line to the columns of the grid electrode 302 in synchronization with the sequential driving (scanning) of the element rows one column at a time, irradiation of each electron beam to the fluorescent film 114 is performed. 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 configured with a photosensitive drum.

[0123]

【Example】

Example 1 and Comparative Examples 1 and 2 As a first example of the present invention, the surface conduction electron-emitting device shown in FIG. 1 was manufactured according to the manufacturing process of FIG. The process will be described below.

Step-a On the insulating substrate 1 made of quartz, as a thin film for device electrodes, T was formed.
Films of i50Å and Pt250Å were formed. A resist was spinner-coated on this, and exposed and developed using a mask for electrode patterns to form an electrode pattern of the resist.
After removing the excess thin film by etching, the resist was removed to obtain device electrodes 4 and 5 (FIG. 3A).

Step-b A Cr film was formed on the entire surface by a sputtering method, a resist was spinner-coated on the Cr film, and a pattern for forming a first layer described later was exposed using a photomask. This was developed to remove unnecessary resist, the unnecessary Cr film was removed by etching to form an opening, and the remaining resist was removed. Organic Pd complex solution (Okuno Pharmaceutical Co., Ltd.)
Product: CCP4230) spinner coated, 300 ° C
It heat-processed for 12 minutes and formed the PdO film. This coating / baking process was repeated 7 times, and the Cr film and the unnecessary PdO film were removed by lift-off to form the first layer 3a (FIG. 3).
(B)).

Step-c A pulse voltage was applied between the device electrodes 4 and 5 to form a crack 31 in a part of the first layer 3a. The applied voltage has a pulse width of 1
It was a triangular wave pulse with a pulse interval of 10 msec and msec, and the pulse height was increased from 0 V to 14 V at 5 V / min (FIG. 3C).

Step-d After forming the Cr film opening in the same manner as in Step-b,
A W film was formed by the sputtering method, and the second layer 3b was formed by lift-off (FIG. 3 (d)).

Step-e Similar to the step-c, a crack was formed in the second layer 3b to form the electron emitting portion 2 (FIG. 3 (e)).

As Comparative Example 1, step-a of Example 1 above.
After forming a PdO film so that the total film thickness is the same as that of the conductive thin film 3 of Example 1 in the same manner as in steps b to b, the process-
The electron-emitting portion was formed by carrying out the energization treatment of c. The voltage of the forming process is the same as that in the first embodiment.

Further, as Comparative Example 2, after the device electrodes 4 and 5 were prepared in the same manner as in Example 1, PdO was formed in step-b.
A W film was formed instead of the film, and a Pt film was formed by omitting step-c to form a conductive thin film, and the same forming process as in Example 1 was performed to form an electron emitting portion.

As described above, Example 1 and Comparative Example 1,
A plurality of elements of No. 2 are produced, and I _e and I _{f of} each element are manufactured.
Was measured by the measurement system shown in FIG. The applied voltage is a 14 V rectangular wave pulse with a pulse interval of 10 msec.
The pulse width is 0.1 msec. In addition, the anode electrode 5
The distance H between 4 and the element is 2 mm, and the extraction voltage is 1 kV.

[0132] I _e, the value of I _f is slightly different for each element, but about 6 times I _e as compared with Example 1. Comparative Example 1, showed about 2 times greater value I _f. The fact that the improvement in I _e exceeds the improvement in I _f means that an electron-emitting device with sufficient performance can be designed with low power consumption, and a very desirable result was obtained.

Next, when I _e and I _f were compared between Example 1 and Comparative Example 2, although the respective values were slightly different for each element,
It was almost the same value. However, the forming current, which is the maximum value of the current required for crack formation, was required to be 5 times the forming current of the second layer of the element of Example 1 in the element of Comparative Example 2.

When the forming current value is large, there is no problem when forming each element, but when forming a plurality of elements arranged side by side by wiring electrodes, an excessive current flows to the wiring electrodes. There are problems such as heat generation and, in severe cases, cracking of the substrate. Therefore, it is desirable in manufacturing that the forming current be kept small.

The device of Example 1 was capable of forming cracks with a small forming current value, and had a large electron emission amount, which was a very desirable result. Further, when each device was operated in vacuum, the device of Example 1 showed a smaller amount of deterioration of the emission current as compared with Comparative Example 1, and favorable results were obtained. Although the melting point in the thin film state is unknown, the melting point of the bulk metal is 1555 ° C. for Pd and 3655 ° C. for W.

[Embodiment 2] Similar to Embodiment 1, FIG.
The surface conduction electron-emitting device shown in was produced. However, in the conductive thin film, the first layer was an Au film and the second layer was an Ir film. The melting points of Au are 1063 ° C. and Ir are 2454 ° C., respectively. When this element was measured and evaluated in the same manner as in Example 1,
The same effect as in Example 1 was obtained.

Example 3 and Comparative Example 3 As a third example of the present invention, a simple matrix electron source shown in FIG. 7 was produced. A plan view of a part of the electron source is shown in FIG. 14 is a sectional view taken along the line AA 'in FIG. 14, and FIGS. 15 to 16 show the manufacturing process of this electron source. However, the same reference numerals in FIGS. 13 to 16 indicate the same things. Here, 141 is an interlayer insulating layer, and 142 is a contact hole. The manufacturing process will be described in detail below with reference to FIGS.

Step-a On a cleaned soda-lime glass, a Cr film having a thickness of 50Å, a thickness of 6
000 Å Au are sequentially laminated, and a photoresist (AZ1
370, manufactured by Hoechst Co., Ltd. by spin coating,
After baking, the 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 the lower wiring 102 having a desired shape.
Was formed.

Step-b Next, an interlayer insulating layer 141 made of a silicon oxide film having a thickness of 1000 L was deposited by a high frequency sputtering method.

Step-c A photoresist pattern for forming the contact hole 142 was formed in the silicon oxide film deposited in the step-b, and the interlayer insulating layer 141 was etched using this as a mask to form the contact hole 142. The etching is RIE (Reactive) using CF ₄ and H ₂ gas.
Ion Etching) method.

Step-d: Form a photoresist (RD2000N-41, manufactured by Hitachi Chemical Co., Ltd.) having a pattern to be a gap between the device electrodes,
50 Å Ti and 1000 Å N by vacuum deposition
i were sequentially laminated, the photoresist was dissolved in an organic solvent, and the excess Pt film was lifted off to form element electrodes 4 and 5. The element electrode gap L was 2 μm.

Step-e After forming a photoresist pattern for the upper wiring 103 on the device electrodes 4 and 5, Ti having a thickness of 50 Å and thickness of 3000 is formed.
Au of Å was sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form the upper wiring 103 having a desired shape.

Step-f A resist film is formed so as to cover portions other than the contact holes 142, and Ti having a thickness of 50Å is formed by a vacuum evaporation method.
000 Å Au were sequentially laminated. Contact holes 142 were filled by removing unnecessary portions by lift-off.

Step-g A Cr film was deposited and patterned in the same manner as in Example 1, and then Pd was formed by a sputtering method.
The film was baked at 0 ° C. for 15 minutes in the atmosphere to form a PdO film.
Subsequently, unnecessary PdO was removed together with the Cr mask by lift-off to form the first-layer conductive thin film 3a.

As shown in FIG. 18, the Y-direction wiring (upper wiring) 103 is used as a common connection, and the X-direction wiring (lower wiring) 1
The element connected to No. 02 was energized line by line to form a crack 31 in the first layer. In the figure, reference numeral 102 is a lower wiring which is a wiring in the X direction, and 103 is an upper wiring which is a wiring in the Y direction, which are grounded via a common electrode 181. One electron-emitting device 104 of the present invention is arranged corresponding to each intersection of the upper wiring and the lower wiring. 18
A pulse generator 2 has a positive electrode connected to one of the lower wirings 102, and a negative electrode connected to the ground via a shunt resistor 183. Reference numeral 184 is an oscilloscope for monitoring the pulse current. The applied pulse is the same as that described in the first embodiment.

Step-h In the same manner as in Step-g, after forming a pattern, Ir was formed into a film by a sputtering method and subjected to energization treatment to form an electron-emitting portion 2.

Through the above steps, the lower wiring 102, the interlayer insulating layer 141, the upper wiring 103, the device electrodes 4, 5 and the conductive thin film 3 were formed on the insulating substrate 1.

Next, as Comparative Example 3, in the same manner as in Example 3 above, only the Ir film was deposited so as to have the same total film thickness of the PdO film and the Ir film of Example 3, and forming was performed. I did. As a result, in Comparative Example 3, in order to form a crack in the conductive thin film, a current which is 5 times the forming current value which is the maximum value of the current required for forming a crack in the first layer in Example 3 was required. .

The electron sources of the above Example 3 and Comparative Example 3 are shown in FIG.
As shown in FIG. 9, the extraction electrode 198 and the fluorescent plate were attached, and all the elements were time-sequentially scan-driven. The surface conduction electron-emitting device applies a driving pulse to the X-direction wiring during driving by utilizing the non-linear characteristic that almost no current flows and the electron emission does not occur when the applied voltage is below a certain threshold. Then, by setting the Y-direction wiring connected to the element to be lit to the ground level, and setting the other Y-direction wiring to the middle of the maximum voltage of the pulse and the ground level (half-selection voltage), only the element at the desired position It can emit electrons.

The measurement system of FIG. 19 will be described. Reference numeral 191 denotes a vacuum chamber, which is 5 × 10 ⁻⁷ torr due to an exhaust system (not shown).
Exhausted below. 192 is a window, 1 is an element substrate, 1
Reference numeral 94 is an element body including an electron emitting portion, electrodes, wirings and the like. Reference numerals 195 and 196 are drive wirings for X-direction and Y-direction lines, respectively. A driver 197 applies an appropriate pulse to the wiring. Reference numeral 198 denotes an extraction electrode, which is obtained by fitting glass on which an ITO thin film of a transparent electrode is formed into an aluminum frame and applying a phosphor on the lower surface thereof.

Drive voltage 14V, half selection voltage 7V
A rectangular wave pulse was applied by a driver so that The extraction voltage was 5 kV.

When the light emission of the phosphor due to electron emission was visually observed through the window 192, it was found that the electron source of Example 3 was
The same luminance was recognized as compared with the electron source of Comparative Example 3.

The display panel shown in FIG. 8 was constructed using each of the above electron sources to form the image display device of the present invention.

After fixing the unformed electron source substrate 1 manufactured in the above step to the rear plate 111, the electron source 1
5 mm above, a face plate 116 (a fluorescent film 114 and a metal back 116 are formed on the inner surface of the glass substrate 113) is sufficiently aligned and arranged via a support frame 112, and the face plate 116 is supported. Frame 11
2. Frit glass was applied to the joint portion of the rear plate 111, and baked at 400 ° C. to 500 ° C. for 10 minutes or more in the air to seal the frit glass. Further, the frit glass was used to fix the electron source substrate 1 to the rear plate 111.

In this embodiment, the fluorescent material has a stripe shape (see FIG. 9A), a material having graphite as a main component is used as the material of the black stripe, and the glass substrate 11 is used.
A slurry method was used as a method for applying a phosphor to No. 3.

Further, the metal back 115 provided on the inner surface side of the fluorescent film 114 performs a smoothing process (filming) on the inner surface side of the fluorescent film after the fluorescent film is produced, and then A
1 was vacuum-deposited. Face plate 1
16 may be provided with a transparent electrode on the outer surface side of the fluorescent film 114 in order to further increase the conductivity of the fluorescent film 114, but in this embodiment, sufficient conductivity was obtained only with the metal back 115. Omitted.

The atmosphere in the glass container completed as described above is exhausted by a vacuum pump through an exhaust pipe (not shown), and after reaching a sufficient degree of vacuum, the external terminals D _{x1 to} D _xm to D _y1. A voltage was applied between the device electrodes through D _yn to perform a forming process to form an electron emitting portion. At this time, the voltage waveform of the forming treatment was the same as that of Example 1, and was performed in a vacuum atmosphere of about 1 × 10 ⁻⁵ torr.

Next, in a vacuum atmosphere having a vacuum degree of 10 ^-5 torr, a voltage pulse of 20 V was repeatedly applied for 30 minutes to deposit 80 Å of a compound containing carbon as a main component.

At a vacuum degree of about 1 × 10 ^−6.5 torr,
Fusing the exhaust pipe (not shown) by heating it with a gas burner,
The envelope 118 was sealed.

Finally, in order to maintain the degree of vacuum after sealing, a getter process was performed by a high frequency heating method.

The terminals D _{x1 to} D _xm to D _{y1 to} D _yn outside the container and the high voltage terminal H of the display panel manufactured as described above.
Each v was connected to a required drive system to complete the image forming apparatus. External terminals D _{x1 to} D _xm to D _y1 to each SCE
Electrons are emitted by applying a scanning signal and a modulation signal by a signal generating means (not shown) through D _yn , and a few k is applied to the metal back 115 through the high voltage terminal Hv.
A high voltage of V or more is applied to accelerate the electron beam, and the fluorescent film 1
A good image was displayed by colliding with 14 and exciting and emitting light.

[Embodiment 4] FIG. 17 is an example of a display device in which the image forming apparatus of Embodiment 3 is configured to display image information provided from various image information sources such as television broadcasting. It is a figure for showing. 2 in the figure
80 is a display panel, 261 is a display panel drive circuit, 262 is a display controller, 2
63 is a multiplexer, 264 is a decoder, 265 is an input / output interface circuit, 266 is a CPU, 267 is an image generation circuit, 268, 269 and 270 are image memory interface circuits, 271 is an image input interface circuit, 272 and 273 are TV signal reception. Circuit, 27
Reference numeral 4 is an input unit. It should be noted that 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, storage, etc. of audio information not directly related to are omitted.

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

First, the TV signal receiving circuit 273 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The system of the TV signal to be received is not particularly limited, and various systems such as NTSC system, PAL system and SECAM system may be used. Further, a TV signal (for example, a so-called high-definition TV such as the MUSE method) including a larger number of scanning lines than these is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. It is a signal source. TV received by the TV signal receiving circuit 273
The signal is output to the decoder 264.

The image TV signal receiving circuit 272 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 273, the TV signal system to be received is not particularly limited, and the TV signal received by this circuit is also output to the decoder 264.

Further, the image input interface circuit 27
Reference numeral 1 denotes 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 264.

Further, the image memory interface circuit 2
70 is a video tape recorder (hereinafter abbreviated as VTR)
The circuit for fetching the image signal stored in is output to the decoder 264.

Further, the image memory interface circuit 2
Reference numeral 69 denotes a circuit for capturing the image signal stored in the video disc, and the captured image signal is output to the decoder 264.

The image memory-interface circuit 268 is a circuit for fetching an image signal from a device that stores still image data, such as a so-called still image disc. The fetched still image data is decoded by the decoder 26.
4 is output.

Further, the input / output interface circuit 265
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 266 of the display device and the outside.

Further, the image generation circuit 267 receives image data, character / graphic information, or CPU 266 input from the outside via the input / output interface circuit 265.
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 264, but in some cases, it can be output to an external computer network or printer via the input / output interface circuit 265.

Further, the CPU 266 mainly carries out operations relating 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 263, and the image signals to be displayed on the display panel 280 are appropriately selected or combined. At that time, a control signal is generated for the display panel controller 262 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.

Image data or character / graphic information is directly output to the image generation circuit 267, or an external computer or memory is accessed via the input / output interface circuit 265 to generate image data or character / figure information.
Enter graphic information.

It should be noted that the CPU 266 may of course be involved in work for purposes other than this. For example, like a personal computer or word processor,
It may be directly related to the function of generating and processing information.

Alternatively, as described above, it may be connected to an external computer network through the input / output interface circuit 265, and work such as numerical calculation may be performed in cooperation with an external device.

The input unit 274 is the CPU 266.
The user inputs commands, programs, data, and the like, and various input devices such as a joystick, a bar code reader, and a voice recognition device can be used in addition to a keyboard and a mouse.

Further, the decoder 264 converts various image signals input from the above 267 to 273 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 preferable that 64 has an image memory therein. This is to handle a television signal that requires an image memory for reverse conversion, such as the MUSE method. Further, the provision of the image memory facilitates the display of a still image, or the image generation circuit 26.
This is because, in cooperation with the CPU 7 and the CPU 266, there is an advantage that image processing and editing such as image thinning, interpolation, enlargement, reduction, and composition can be easily performed.

Also, the multiplexer 263 is the CPU
The display image is appropriately selected based on the control signal input from 266. That is, the multiplexer 263 selects a desired image signal from the inversely converted image signals input from the decoder 264 and outputs it to the drive circuit 261. 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. .

Also, the display panel controller 2
Reference numeral 62 is a circuit for controlling the operation of the drive circuit 261 based on a control signal input from the CPU 266.

First, regarding the basic operation of the display panel, for example, a signal for controlling the operation sequence of the power source (not shown) for driving the display panel is output to the drive circuit 261.

Further, regarding the driving method of the display panel, for example, a signal for controlling the screen display frequency and the scanning method (for example, interlace or non-interlace) is output to the drive circuit 261.

In some cases, control signals relating to image quality adjustment such as brightness, contrast, color tone, and sharpness of a display image may be output to the drive circuit 261.

The drive circuit 261 is a circuit for generating a drive signal to be applied to the display panel 280. The drive circuit 261 receives an image signal input from the multiplexer 263 and a control signal input from the display panel controller 262. It operates based on.

The functions of the respective parts have been described above. With the configuration illustrated in FIG. 17, the display panel 2 displays image information input from various image information sources in this display device.
70 can be displayed. That is, various image signals such as television broadcasts are inversely converted by the decoder 264, appropriately selected by the multiplexer 263, and input to the drive circuit 261. On the other hand, the display controller 262 generates a control signal for controlling the operation of the drive circuit 261 according to the image signal to be displayed. The drive circuit 261 applies a drive signal to the display panel 280 based on the image signal and the control signal. As a result, the image is displayed on the display panel 280. These series of operations are performed by the CPU 2
It is totally controlled by 66.

Further, in the present display device, the image memory built in the decoder 264 and the image generation circuit 267 are provided.
With the involvement of the CPU 266, not only the selected one of the plurality of image information is displayed, but also the image information to be displayed is enlarged, reduced, rotated, moved, edge emphasized, thinned, interpolated, or the like. 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. Further, in the description of this embodiment,
Although not particularly mentioned, a dedicated circuit for processing and editing audio information may be provided as in the above-mentioned image processing and image editing.

Therefore, the present display device 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, and a game. It is possible to combine the functions of a machine, etc., and has a very wide range of applications for industrial or consumer use.

It is needless to say that FIG. 17 described above merely shows an example of the image forming apparatus of the present invention, and the present invention is not limited to this. For example, of the constituent elements of FIG. 17, circuits relating to functions that are unnecessary 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 display device 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 this display device, in particular, since it is easy to thin the display panel using the surface conduction electron-emitting device as an electron source, the depth of the display device can be reduced. In addition, a display panel using surface conduction electron-emitting devices as an electron source can easily make a large screen, has high brightness, and has excellent viewing angle characteristics, so that this display device provides a realistic and powerful image. It can be displayed well.

Furthermore, since the electron source of the present invention has uniform electron emission characteristics among the surface conduction electron-emitting devices, the quality of the formed image is high and a high-definition image can be displayed. .

[0192]

As described above, according to the present invention,
It is possible to obtain a surface conduction electron-emitting device having uniform and improved electron emission characteristics without taking complicated electric control means. Therefore, an even electron source can be obtained for each device and high display quality can be obtained. An image forming apparatus is provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a surface conduction electron-emitting device of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the surface conduction electron-emitting device of the present invention.

FIG. 3 is a diagram showing an example of a manufacturing process of a surface conduction electron-emitting device of the present invention.

FIG. 4 is a diagram showing a voltage waveform of an energization process for manufacturing the surface conduction electron-emitting device of the present invention.

FIG. 5 is a diagram showing a measurement evaluation system for evaluating electron emission characteristics of the surface conduction electron-emitting device of the present invention.

FIG. 6 is a diagram showing electron emission characteristics of the surface conduction electron-emitting device of the present invention.

FIG. 7 is a schematic diagram of a simple matrix electron source of the present invention.

FIG. 8 is a diagram showing an embodiment of a display panel of the image forming apparatus of the present invention.

FIG. 9 is a diagram showing a fluorescent film used in the image forming apparatus of the present invention.

FIG. 10 is a block diagram of an embodiment of the image forming apparatus of the present invention.

FIG. 11 is a schematic view of a ladder type electron source of the present invention.

FIG. 12 is a diagram showing a display panel of an image forming apparatus of the present invention using a ladder type electron source.

FIG. 13 is a diagram showing an electron source of Example 3 of the present invention.

FIG. 14 is a partial sectional view of an electron source of Example 3 of the present invention.

FIG. 15 is a manufacturing process diagram of the electron source of Example 3;

FIG. 16 is a manufacturing process diagram of the electron source of Example 3;

FIG. 17 is a block diagram of an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 18 is a diagram showing a connection form during forming of an electron source according to the third embodiment of the present invention.

FIG. 19 is a diagram showing a measurement system of an electron source according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Electron emission part 3 Conductive thin film 3a 1st layer 3b 2nd layer 4,5 Element electrode 21 Step forming member 31 Crack 50 Ammeter 51 Power supply 52 Ammeter 53 High voltage power supply 54 Anode electrode 55 Vacuum device 56 Exhaust Pump 102 X-direction wiring 103 Y-direction wiring 104 Surface conduction electron-emitting device 105 Connection 111 Rear plate 112 Support frame 113 Glass substrate 114 Fluorescent film 115 Metal back 116 Face plate 118 Envelope 121 Black conductive material 122 Phosphor 141 Inter-layer Insulation layer 142 Contact hole 181 Common electrode 182 Pulse generator 183 Shunt resistance 184 Oscilloscope 191 Vacuum chamber 192 Window 194 Element body 195 X-direction drive wiring 196 Y-direction drive wiring 197 Driver 198 Extraction electrode 199 Source 201 Display panel 202 Scanning circuit 203 Control circuit 204 Shift register 205 Line memory 206 Synchronous signal separation circuit 207 Modulation signal generator 261 Drive circuit 262 Display panel controller 263 Multiplexer 264 Decoder 265 Input / output interface 266 CPU 267 Image generation circuit 268 Image memory Interface 269 Image memory interface 270 Image memory interface 271 Image input memory interface 272 TV signal receiving circuit 273 TV signal receiving circuit 274 Input section 280 Display panel 301 Display panel 302 Grid electrode 303 Opening 304 Common wiring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 49/00 // H04N 5/66 Z

Claims (11)

[Claims] 1. An electron-emitting device comprising a pair of device electrodes provided on an insulating substrate so as to face each other, and a conductive thin film having an electron-emitting portion provided between the device electrodes,
The conductive thin film is composed of at least two upper and lower layers, the first thin film has a crack approximately in the middle between the device electrodes, and the second thin film is made of a material having a higher melting point than the first layer. Surface conduction characterized by being formed on the thin film of and in the crack of the first layer, and the crack of the thin film of the second layer being formed inside the crack of the first layer to form an electron emission part. Electron-emitting device. 2. The surface conduction electron-emitting device according to claim 1, wherein the device electrodes are flat devices formed on the same surface. 3. The surface conduction electron according to claim 1, wherein the device electrodes are vertically arranged with an insulating layer interposed therebetween, and a conductive thin film is formed on a side surface of the insulating layer. Emissive element. 4. A ladder-like arrangement in which at least one row of the electron-emitting devices according to any one of claims 1 to 3 is arranged in parallel and connected and the wiring for driving each device is a ladder-like arrangement. An electron source characterized by being stored. 5. The device according to claim 1, further comprising at least one device row in which a plurality of electron-emitting devices are arranged, and wirings for driving the devices are arranged in a matrix. Electron source. 6. An image forming apparatus comprising the electron source according to claim 4, an image forming member, and a control electrode for controlling an electron beam emitted from each element according to an information signal. 7. An image forming apparatus comprising the electron source according to claim 5 and an image forming member. 8. The method of manufacturing a surface conduction electron-emitting device according to claim 1, wherein a thin film of a first layer is formed between device electrodes on an insulating substrate, and the thin film is cracked by an electric current treatment. A method of manufacturing a surface-conduction electron-emitting device, characterized in that after the forming step, the step of forming a thin film of the second layer and conducting an electric current to form a crack is repeated once or a plurality of times. 9. A method of manufacturing an electron source according to claim 8, wherein a plurality of surface conduction electron-emitting devices are formed on the same substrate. 10. An electron source is manufactured by the manufacturing method according to claim 9, and the obtained electron source is irradiated with an electron beam emitted from the electron source and a control electrode for controlling an electron beam emitted from the electron source. A method for manufacturing an image forming apparatus, characterized in that the method is combined with an image forming member for forming an image. 11. An image produced by manufacturing an electron source by the manufacturing method according to claim 8, and combining the obtained electron source with an image forming member which forms an image by irradiation of an electron beam from the electron source. Manufacturing method of forming apparatus.