JPH0864112A - Electron emitting device, electron source, and image forming apparatus using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the stability and durability of a surface conduction electron-emitting device used as an electron source of an image forming apparatus or the like. In a surface conduction electron-emitting device in which an electron emitting portion 2 is provided in a conductive thin film 3 that connects between device electrodes 4 and 5 provided on a substrate 1, the conductive thin film 3 is made of a metal oxide. The device electrodes 4 and 5 are the substrate 1 and the conductive thin film 3.
Subbing layers 4a and 5a made of a conductive oxide in contact with
It is characterized in that it is composed of metal electrode layers 4b and 5b covering the undercoat layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron-emitting device, particularly a surface conduction electron-emitting device, an electron source provided with a plurality of such devices, and an image of a display device, an exposure device or the like constructed by using the electron source. Forming apparatus

[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. 18, after a pair of device electrodes 4 and 5 made of metal electrodes are formed on an insulating substrate 1, the device electrodes are formed. Conductive thin film 3 such as metal oxide that connects between 4 and 5
And the electron emitting portion 2 is formed on the conductive thin film 3 by an energization process called forming. Forming is usually performed by applying a voltage across both ends of the conductive thin film 3, locally destroying, deforming or degrading the conductive thin film 3 to change the structure, and to form an electron with a high electrical resistance. This is a process of forming the emitting portion 2. The electron emission is performed by the conductive thin film 3 on which the electron emission portion 2 is formed.
A voltage is applied to the electrons to cause a current to flow, and
It is performed from the vicinity of the crack that occurred in the.

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. 1-257552).

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]

In the conventional surface conduction electron-emitting device, when metal oxide is selected as the material of the conductive thin film 3, the device electrodes 4, 5 made of metal electrodes and the conductive thin film 3 are used. It was difficult to secure sufficient adhesion with the element, and therefore, a sufficiently satisfactory element in terms of stability and durability could not be obtained.

Usually, a thin undercoat layer of Cr, Ti or the like is formed in order to improve the adhesion between the device electrodes 4, 5 made of metal electrodes and the substrate 1. For example, the device electrodes are formed in the same manner as described above. If the above-mentioned undercoating layer is formed at the interface between the conductive thin film 3 and the conductive thin film 3 to improve the adhesion between them, the above-mentioned undercoating layer is highly reactive with oxygen, so that it may come into contact with a metal oxide. By doing so, CrO, TiO, or the like is formed, the contact resistance between the element electrode and the conductive thin film increases, and the driving voltage of the element rises.

In view of the above problems of the prior art, the present invention provides a surface conduction electron-emitting device having a conductive thin film provided with an electron emitting portion, an electron source using the same, and an image forming apparatus. The purpose of the invention is to improve stability and durability without unnecessarily increasing the driving voltage of

[0010]

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

That is, a first aspect of the present invention is an electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects a pair of device electrodes provided on a substrate, and the conductive thin film is a metal oxide. The electron-emitting device is a film, and the device electrode is a conductive oxide electrode.

A second aspect of the present invention is an electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects a pair of device electrodes provided on a substrate, and the conductive thin film is a metal oxide. In the electron-emitting device, which is a film, at least a portion of the device electrode in contact with the substrate and the conductive thin film is a conductive oxide electrode.

The second aspect of the present invention is further characterized in that the element electrode comprises a conductive oxide electrode and a metal electrode.

The first and second aspects of the present invention are further characterized in that the conductive oxide electrode is In ₂ O.
₃ , SnO ₂ , or a mixture thereof.

A third aspect of the present invention is an electron source characterized by comprising a plurality of the above-mentioned 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 element row in which a plurality of electron-emitting elements are arranged, and a wiring for driving each electron-emitting element 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 is characterized by having the above-mentioned third electron source of the present invention and an image forming member for forming an image by irradiation of an electron beam emitted from the electron source. It is in the forming device.

As described above, the present invention particularly relates to a surface conduction electron-emitting device as an electron-emitting device, an electron source in which a plurality of surface-conduction electron-emitting devices are arranged, and an image forming apparatus using the electron source. Then, the configuration and operation of each invention will be further described below.

The basic structure of the surface conduction electron-emitting device of the present invention is not limited to that shown in FIG. 18, but may be the reverse of the device structure shown in FIG. 18 as shown in FIG.
In these figures, 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.

In the case of the device configuration shown in FIG. 18, when the device electrodes 4 and 5 are formed and then the organic metal-containing solution is applied by the spinner method or the like to form the conductive thin film 3, the obtained conductive thin film 3 is obtained. It tends to be thick near the element electrode and thin at the center. On the other hand, when the device configuration shown in FIG. 1 is used,
In order to eliminate unevenness in the thickness of the conductive thin film 3 and to relatively easily control the thickness, the electron-emitting portion 2 formed by the forming process described later can be made uniform, and the electron-emitting characteristics of each element can be made uniform. Is preferred.

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,
A conductive oxide is used, for example, In ₂ O ₃ , SnO.
₂ , RuO ₂ , ITO, or a mixture thereof is appropriately selected. By using the above-mentioned conductive oxide for the device electrodes 4 and 5, it is possible to obtain sufficient adhesion to the substrate 1 and the conductive thin film 3 made of a metal oxide described later.

Further, in the case of the element structure shown in FIG. 1, the element electrodes 4 and 5 are formed of the above-mentioned conductive oxide as the undercoat layers 4a and 5a and the general conductive material as shown in FIG. It can be composed of the metal electrode layers 4b and 5b. That is,
The above-mentioned conductive oxide is used as the subbing layers 4a and 5a in the portion in contact with the substrate 1 and the conductive thin film 3, and is further covered with the metal electrodes 4b and 5b. While maintaining the adhesion with the thin film 3 and the electrical contact with the conductive thin film 3, the metal electrode layers 4b, 5
It is preferable because it can have features such as high electrical conductivity and high thermal conductivity due to b.

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

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

The main materials constituting the conductive thin film 3 are, for example, PdO, SnO ₂ , In ₂ O ₃ , PbO, Sb ₂ O _3.
And other metal oxides.

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 to 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 individually 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.

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, 2 and 18.

The crack 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 can be considered as a method for manufacturing the basic structure of the surface conduction electron-emitting device of the present invention.
An example of the surface conduction electron-emitting device having the configuration shown in FIG. 3 will be described below based on the manufacturing process chart of FIG. still,
The steps a to c shown below correspond to (a) to (c) of FIG.

Step a: After the substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, an organometallic solution is applied and left to stand to form an organometallic film. 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 film is heated and baked to form a metal oxide, and the conductive thin film 3 patterned by lift-off, etching or the like is formed. 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.

Step b: After depositing the element electrode material of the conductive oxide on the substrate 1 provided with the conductive thin film 3 by the vacuum deposition method, the sputtering method or the like, the element having a desired shape is formed by the photolithography technique. The electrodes 4 and 5 are formed.

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.

It is preferable to further perform an activation step.

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 drive voltage applied when driving the element.

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.

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 and evaluation system for measuring the electron emission characteristics of the surface conduction electron-emitting device. First, this measurement and 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, etc. 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.

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 and evaluation system is set to 1 kV to 10 kV and the distance H between the anode electrode 54 and the surface conduction electron-emitting device is H. Is usually set to 2 mm to 8 mm, and the normal measurement is performed.

First, the emission current Ie and the device current If,
FIG. 6 (solid line in the figure) shows a typical example of the relationship of the element voltage Vf.
Shown in In FIG. 6, the emission current Ie is the device current Ie.
Since it is significantly smaller than f, it is shown in arbitrary units.

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

First, in the surface conduction electron-emitting device, when a device voltage Vf higher than a certain voltage (called threshold voltage: Vth in FIG. 6) is applied, the emission current Ie rapidly increases, while At the threshold voltage Vth or less, 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 the characteristic of monotonically increasing with respect to the element voltage Vf (called 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 characteristic characteristics of the surface conduction electron-emitting device of the present invention as described above, even in an electron source or an image forming apparatus in which a plurality of devices are arranged, the amount of emitted electrons can be easily adjusted according to an input signal. Since it can be controlled, 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 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 appropriately set according to the application. Is.

The m X-direction wirings 102 have external terminals DX1, DX2, ... DXm, respectively, 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 evaporation 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, even if some or all of the constituent elements of the m X-direction wirings 102, the n Y-direction wirings 103, the connection lines 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 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 later in detail, 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. 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 an SC system television signal.

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 on which the substrate 1 is fixed, and 116 is a glass substrate 1.
The fluorescent film 114, which is an image forming member, is formed on the inner surface of 13.
And a face spray formed with a metal back 115 and the like.
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. 8, 102 and 103 are X-direction wirings and Y-direction wirings connected to the pair of device electrodes 4 and 5 (see FIGS. 1 and 2) of the surface conduction electron-emitting device 104, each of which is an external terminal. Dx1 to Dxm, Dy1 to D
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.

In the case of monochrome, the fluorescent film 114 is composed of only the phosphor 122, but in the case of color, the phosphor 1 is used.
22 stripes, black stripes (Fig. 9 (a))
Alternatively, it is composed of a black conductive material 121 called a black matrix (FIG. 9B) and the like, and a phosphor 122.
The purpose of providing the black stripes and the black matrix is to provide each of the three primary color phosphors 12 required for color display.
It is to make the color-mixed portions between the two black so as to make the color mixture inconspicuous and to suppress the deterioration of the contrast due to the reflection of external light on the fluorescent film 114. Black conductive material 12
As the material of No. 1, 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 having conductivity and little transmission and reflection of light.

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 allow the light emitted from the phosphor 122 (see FIG. 9) toward the inner surface side to face the face plate 11.
6 to improve the brightness by specular reflection, to act as an electrode for applying an electron beam accelerating voltage from the high voltage terminal Hv, and to prevent damage due to collision of negative ions generated in the envelope 118. For example, protection of the fluorescent substance 122 from the light. 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.

When the above-mentioned sealing is performed, 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 ^-7 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 forming and activating steps described above are usually performed immediately before or after sealing the envelope 118, and the contents thereof are as described above.

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. 10, 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. 10, 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
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 includes therein m switching elements (schematically shown by S1 to Sm in FIG. 10).
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 type electron-emitting devices which are not scanned, based on the characteristics (threshold voltage) of the surface-conduction type 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 the 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 separation circuit 206 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input 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 performing 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 appropriately stores the contents of Id1 to Idn according to 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 that can appropriately modulate 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.

Further, 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 example, a well-known D / A conversion circuit may be used as the modulation signal generator 207, 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 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 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. 11 and 12.

In FIG. 11, 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.

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 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. 12 is a diagram showing the structure of a display panel 301 provided with the above-mentioned ladder-type electron sources.

In FIG. 12, 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.

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 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 shape is not necessarily 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, 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, etc. 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.

[0111]

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

Example 1 A surface conduction electron-emitting device having the structure shown in FIG. 1 was produced as the electron-emitting device of this example. FIG. 1A shows a plan view of this element, and FIG. 1B shows a sectional view. In the figure, W represents the width of the device electrodes 4 and 5, L represents the distance between the device electrodes 4 and 5, and d represents the thickness of the device electrodes.

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: A quartz substrate is used as the substrate 1, which is thoroughly washed with an organic solvent, coated with an organic palladium-containing solution, and then heat-treated at 300 ° C. for 10 minutes to obtain palladium oxide (PdO). Fine particles (average particle size: 7n
A fine particle film of m) was formed to obtain the conductive thin film 3.
Here, the conductive thin film 3 had a width of 300 μm and a length of 500 μm.

The particle diameter of the fine particles described here means the diameter of the fine particles whose particle shape can be recognized.

Step b: Device electrodes 4 and 5 made of ITO were formed on the substrate 1 on which the conductive thin film 3 was formed. This time,
The element electrode spacing L is 3 μm, and the element electrode width W is 500 μm.
m and its thickness d was 100 nm. The resistance value between the device electrodes 4 and 5 was 250Ω to 300Ω.

For comparison, the device electrodes 4 and 5 were replaced with Ti / P.
In the case of t (Ti is an undercoat layer to 3 nm), TiO is formed at the interface with the conductive thin film 3, so that the contact resistance with the conductive thin film 3 becomes very high, and the element The resistance value between the electrodes 4 and 5 was 1 kΩ to 10 kΩ.

Step c: By applying a voltage between the device electrodes 4 and 5 and subjecting the conductive thin film 3 to a forming treatment,
The electron emitting portion 2 was formed. FIG. 4 shows the forming process.
The voltage waveform shown in (a) was used.

In this embodiment, T1 is 1 msec and T2 is 10 m.
The peak value of the triangular wave (peak voltage during forming) is 5 V, and the forming process is about 1 × 10 ⁻⁶ To.
It was performed for 60 seconds under a vacuum atmosphere of rr. The electron-emitting portion 2 thus produced contained cracks, and the fine particles containing palladium element as a main component were dispersed and arranged, and the average particle diameter of the fine particles was 3 nm.

The electron emission characteristics of the surface conduction electron-emitting device produced as described above were measured using the measurement evaluation system shown in FIG.

The measurement conditions are as follows: the distance H between the anode electrode 54 and the surface conduction electron-emitting device is 4 mm, the potential of the anode electrode 54 is 1 kV, and the vacuum device 5 for measuring electron emission characteristics is used.
The degree of vacuum in 5 was set to about 1 × 10 ⁻⁶ Torr. As a result, in the element of this example, the current-voltage characteristics as shown by the solid line in FIG. 6 were obtained. In this element, the element voltage is 8V
The emission current Ie increases sharply from the
And the device current If is 2.2 mA and the emission current Ie is 1.1 μm.
A, and the electron emission efficiency η = Ie / If (%) is 0.0
5%.

Example 2 A surface conduction electron-emitting device having the structure shown in FIG. 2 was produced as the electron-emitting device of this example. FIG. 2A shows a plan view of this element, and FIG. 2B shows a sectional view. In the figure, W represents the width of the device electrodes 4 and 5, L represents the distance between the device electrodes 4 and 5, and d represents the thickness of the device electrodes.

A method of manufacturing the surface conduction electron-emitting device of this embodiment will be described.

(1) A quartz substrate is used as the substrate 1, which is thoroughly washed with an organic solvent, coated with an organic palladium-containing solution, and then heat-treated at 300 ° C. for 10 minutes to obtain palladium oxide (PdO). Fine particles (average particle size: 7n
A fine particle film of m) was formed to obtain the conductive thin film 3.
Here, the conductive thin film 3 had a width of 300 μm and a length of 500 μm.

(2) On the substrate 1 on which the conductive thin film 3 is formed, the undercoat layers 4a and 5a made of ITO having a thickness of 10 nm.
After forming, the metal electrode layers 4b and 5b made of Ni and having a thickness of 90 nm were formed to form the device electrodes 4 and 5. At this time, the device electrode interval L is 3 μm, and the device electrode width W is 500 μm.
μm.

The resistance value between the device electrodes 4 and 5 of this embodiment is 5
It was 0 Ω to 100 Ω, and high electrical conductivity due to the metal electrode layers 4b and 5b could be obtained at the same time while maintaining good electrical contact with the conductive thin film 3.

(3) The electron-emitting portion 2 was formed by performing the forming process in the same manner as in Example 1.

Regarding the device manufactured as described above,
When the electron emission characteristics were measured in the same manner as in Example 1, both the device current If and the emission current Ie increased, and the electron emission efficiency η = Ie / If (%) was 0.08%.

[Embodiment 3] In this embodiment, an electron source as shown in FIG. 7 in which a large number of surface conduction electron-emitting devices having the structure as shown in FIG. 18 are formed and arranged in a simple matrix is used. An example in which an image forming apparatus as shown in FIG. 8 is manufactured will be described.

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 the figure. However, the same reference numerals in FIG. 7, FIG. 8, FIG. 13 and FIG. 14 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, and 401 is an interlayer. An insulating layer 402 is a contact hole for electrically connecting the device electrode 4 and the lower wiring 102.

First, a method of manufacturing the 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: On a substrate 1 in which a 0.5 μm-thick silicon oxide film was formed on a cleaned soda-lime glass by a sputtering method, by vacuum evaporation, Cr having a thickness of 5 nm and a thickness of 6 were formed.
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 the interlayer insulating layer 40 is formed using this as a mask.
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 for forming the gap G between the device electrodes 4 and 5 and the device electrodes is formed by a photoresist (R).
D-2000N-41 manufactured by Hitachi Chemical Co., Ltd.), and ITO having a thickness of 100 nm was deposited by a sputtering method. The photoresist pattern is dissolved in an organic solvent, the ITO deposited film is lifted off, and the element electrode spacing L is 3 μm and the width W 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: FIG. 16 shows a part of a plan view of the mask of the conductive thin film 3 relating to this step. This is a mask having a gap L between the element electrodes and an opening in the vicinity thereof. With this mask, a Cr film 403 having a film thickness of 100 nm is deposited and patterned by vacuum evaporation, and an organic P layer is formed thereon.
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: Cr film 403 by lift-off method
To remove the conductive thin film 3 having a desired pattern shape.
Was formed.

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 produced using the above electron source. The manufacturing procedure will be described below with reference to FIGS.

First, after fixing the substrate 1 of the unformed electron source to the rear plate 111, the face plate 116 (which is an image forming member on the inner surface of the glass substrate 113 is located 5 mm above the substrate 1). The fluorescent film 114 and the metal back 115 are formed.) The support frame 112
Through the face plate 116, the support 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 rear plate 111. 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. 9A), and a black stripe is first formed with the black conductive material 121. Each color phosphor 12 is formed in the gap by the slurry method.
2 was applied to produce a fluorescent film 114. Black conductive material 12
As 1, 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 the present 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 color, the phosphors 122 of the respective colors have to correspond to the electron-emitting devices 104, and therefore, sufficient alignment is performed.

The atmosphere inside the envelope 118 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 Dx1 to Dxm.
And Dy1 to Dyn, a voltage was applied between the device electrodes 4 and 5 of each surface conduction electron-emitting device 104, and a forming process was performed in the same manner as in Example 1 to fabricate the electron-emitting portion 2.

Thereafter, the envelope 1 is passed through an exhaust pipe (not shown).
The inside of 18 was evacuated to a degree of vacuum of about 10 ^-6.5 Torr, and the exhaust pipe was heated by a gas burner to be welded to seal the envelope 118. 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.

In the display panel 201 (see FIG. 8) constructed by using the electron sources of the simple matrix arrangement as described above, scanning signals and modulation signals (not shown) are supplied through the external terminals Dx1 to Dxm and Dy1 to Dyn. Electrons are emitted by applying each to the electron-emitting devices 104 by the signal generating means, and a high voltage of several kV or more is applied to the metal back 115 through the high-voltage terminal Hv to accelerate the electron beam and collide with the fluorescent film 114. Then, an image could be displayed by exciting and emitting light.

[Fourth Embodiment] FIG. 17 shows the display panel (display panel) 201 (see FIG. 8) of the third embodiment, which displays image information provided from various image information sources such as television broadcasting. It is a figure which shows an example of the image display apparatus of this invention comprised so that it could display.

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 receiving a signal including both video information and audio information, such as a television signal, the present display device 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.

It should be noted that 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. 17, 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. 17 shows only an example of the configuration in the case of an image forming apparatus using a display panel having an electron emitting element as an electron beam source, 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. 17, circuits relating to functions 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 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 this image forming apparatus, the display panel 201 according to the present invention can be easily thinned, so that 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.

[0182]

As described above, according to the present invention,
By using a conductive oxide as the device electrode in the surface conduction electron-emitting device, a sufficient adhesion force between the substrate and the conductive thin film is obtained while maintaining the electrical connection with the conductive thin film made of a metal oxide. be able to. This allows
The stability and durability of the device are improved without unnecessarily increasing the drive voltage of the device.

In particular, when the interface portion between the substrate and the conductive thin film is made of a conductive oxide and a metal electrode layer is provided so as to cover the conductive oxide to form an element electrode, the above effect is obtained. In addition, the metal electrode layer can have features such as high conductivity and high thermal conductivity, and the electron emission efficiency of the final device is improved.

Further, an electron source in which a large number of surface conduction electron-emitting devices are arrayed and formed, and an image forming apparatus using the same are
It is possible to fabricate with a higher yield, obtain stable electron emission, and form a bright, high-quality image with low power.

[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 the relationship between the emission current Ie and the device current If and the device voltage Vf of the surface conduction electron-emitting device of the present invention.

FIG. 7 is a schematic diagram of an electron source with a simple matrix arrangement.

FIG. 8 is a partially cutaway perspective view showing a schematic configuration of a display panel provided with an electron source having a simple matrix arrangement.

FIG. 9 is a diagram showing a configuration example of a fluorescent film used in a display panel.

FIG. 10 is a block diagram showing an example of a drive circuit of an image forming apparatus that displays an image in accordance with an NTSC television signal.

FIG. 11 is a schematic view of a ladder-type electron source.

FIG. 12 is a partial cutaway perspective view showing a schematic configuration of a display panel provided with a trapezoidal arrangement of electron sources.

FIG. 13 is a partial plan view of an electron source having a simple matrix arrangement shown in a third embodiment.

FIG. 14 is a partial cross-sectional view of the electron source of FIG.

FIG. 15 is a diagram for explaining a manufacturing process of the electron source in FIG.

16 is a partial plan view of a mask used in a manufacturing process of the electron source of FIG.

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

FIG. 18 is a diagram for explaining the basic configuration of a surface conduction electron-emitting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 Electron emission part 3 Conductive thin film 4,5 Element electrodes 4a, 5a Subbing layers 4b, 5b made of conductive oxide 4b, 5b Metal electrode layer 50 Ammeter for measuring element current If flowing through the conductive thin film 3 51 Power Supply for Applying Element Voltage Vf to Electron Emitting Element 52 Ammeter for Measuring Emission Current Ie Emitted from Electron Emitting Section 2 53 High Voltage Power Supply for Applying Voltage to Anode Electrode 54 Electron Emitting Section Anode electrode for trapping electrons emitted from 2 55 Vacuum device 56 Exhaust pump 102 X-direction wiring 103 Y-direction wiring 104 Surface conduction electron-emitting device 105 Connection 111 111 Rear plate 112 Support frame 113 Glass substrate 114 Fluorescence Membrane 115 Metal back 116 Face plate Hv High voltage terminal 118 Envelope 121 Black conductive material 122 Fluorescent 201 display panel 202 scanning circuit 203 control circuit 204 shift register 205 line memory 206 synchronization signal separation circuit 207 modulation signal generator Va direct current voltage source Vx direct current voltage source 301 display panel 302 grid electrode 303 electron passage opening 304 electron emission Common wiring 401 for wiring the element 104 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 receiving circuit 1014 Input unit

Claims (8)

[Claims] 1. An electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects between a pair of device electrodes provided on a substrate, wherein the conductive thin film is a metal oxide film, and the device electrode Is an electrically conductive oxide electrode. 2. An electron-emitting device in which an electron-emitting portion is provided in a conductive thin film that connects between a pair of device electrodes provided on a substrate, wherein the conductive thin film is a metal oxide film, and the device electrode An electron-emitting device characterized in that at least a portion in contact with the substrate and the conductive thin film is a conductive oxide electrode. 3. The electron emitting device according to claim 2, wherein the device electrode comprises a conductive oxide electrode and a metal electrode. 4. The conductive oxide electrode is In ₂ O ₃ ,
The electron-emitting device according to any one of claims 1 to 3, wherein the electron-emitting device is made of SnO ₂ or a mixture thereof. 5. An electron source comprising a plurality of electron-emitting devices according to claim 1 on a substrate. 6. The electron source has at least one element row in which a plurality of electron emitting elements are arranged, and wirings for driving each electron emitting element are arranged in a matrix. Item 5. The electron source according to item 5. 7. 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 5. 8. An image forming apparatus comprising: the electron source according to claim 5; and an image forming member that forms an image by irradiation with an electron beam emitted from the electron source.