JP3320182B2 - Electron emitting element, electron source and image forming apparatus using the same - Google Patents

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 the electron-emitting devices, and an image forming apparatus using the electron source.

[0002]

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

[0003] The SCE utilizes the phenomenon that electron emission occurs when a current flows in a small area thin film formed on a substrate in parallel with the film surface. As a typical configuration, a pair of device electrodes is provided on an insulating substrate, a metal oxide thin film is formed so as to connect the electrodes, and the thin film is locally formed by an energization process called forming in advance. The thin film before and after the forming is basically formed of a fine particle film. The SCE is a non-linear element in which the emission current increases sharply when an element voltage higher than a certain voltage (threshold voltage) is applied, while the emission current is hardly detected below the threshold voltage. The emission current of the SCE can be controlled by the device voltage, and the emission charge can be controlled by the application time of the device voltage. Further, various display devices are configured by combining an electron source having a plurality of SCEs arranged therein and a phosphor that emits visible light by electrons emitted from the electron source. However, since it is a self-luminous display device that can be manufactured relatively easily and has excellent display quality, it is expected as an image forming device replacing a CRT.

[0004]

The above-mentioned SCE has low adhesion at the interface between the electrode and the thin film on which the electron-emitting portion is provided, and causes peeling or disconnection due to thermal stress generated during forming. There was a case. Further, there is a problem that the electron emission characteristics become unstable due to the peeling.

An object of the present invention is to solve the above-mentioned problems and to provide an electron-emitting device in which peeling or disconnection of a thin film is prevented, an electron source using the device, and an image forming apparatus.

[0006]

In the electron-emitting device of the present invention, a pair of electrodes are embedded in the surface of a substrate, and a thin film is formed on the substrate so that both ends are electrically connected to the electrodes. The SCE is characterized in that an electron emission portion is formed on the thin film. Further, the electron source of the present invention is the same as the above-mentioned SCE.
The present invention also provides an image forming apparatus by combining an image forming member with the electron source.

FIG. 1 shows the basic configuration of the SCE of the present invention. FIG. 1A is a sectional view, and FIG. 1B is a plan view. In the figure, 1 is an insulating substrate, 2 is an electrode, 3 is an insulating layer, 4 is a thin film including an electron emitting portion, 5 is an electron emitting portion, and 6 is an extraction electrode.

In the present invention, the insulating substrate 1 may be quartz glass, glass having a low impurity content such as Na, blue plate glass, a glass substrate obtained by laminating SiO ₂ on a blue plate glass by a sputtering method or the like, or ceramic such as alumina. And the like.

The electrode 2 and the lead electrode 6 may be made of any material as long as it has conductivity. For example, Ni, Cr, Au, Mo,
W, Pt, Ti, Al, Cu, metal or alloy and Pd such as Pd, Ag, Au, printed conductors composed of RuO _2, metal or a metal oxide such as Pd-Ag and glass,
Examples include a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor material such as polysilicon.

In the electron-emitting device of the present invention, the electrode 2
Is embedded in the surface of the substrate 1, but the manufacturing process of this configuration is not particularly limited. For example, an electrode material is embedded by shaving the surface of the substrate 1, or after the electrode 2 is formed on the surface of the substrate 1. Any of the stacked insulating layers 3 may be used. Further, for example, a material that changes into conductive or nonconductive by doping or heat treatment such as an oxide material or a semiconductor material such as silicon, a difference in crystal or amorphous state, or a deviation from the stoichiometric composition is deposited on the substrate 1. A method of laminating and changing the conductivity by the above-described doping or heat treatment and using the conductive region as the electrode 2 is preferably used.

The electrode 2 is a conductive substance formed by a chemical change of the insulating layer 3. In such an electrode configuration, since there is no step at the contact portion between the electrode and the thin film including the electron-emitting portion and the electrode is flat, the problem of peeling of the thin film does not occur.

[0012] The electrode interval L ₁ is a few hundred Å~ is several hundred μm, photo lithography technologies that are the basis of preparation of the electrode,
That is, it is set according to the performance of the exposure machine, the etching method, the voltage applied between the electrodes, the electric field strength capable of emitting electrons, and the like. The electrode length W _1, the resistance value of the film thickness d is the electrode 2, the wiring of the drive wiring is appropriately designed from placement problems of elements for configuring the electron source, typically, W ₁ is the number μm~ Several hundred μm and d is several hundreds of μm to several μm.

In the present invention, the film thickness of the thin film 4 including the electron emitting portion is several Å to several thousand Å, preferably several tens to several hundred Å, and the resistance value between the electron emitting portion 5 and the extraction electrode 6. And the diameter of the conductive fine particles of the electron-emitting portion 5, the energization processing conditions described later, and the like. The resistance value is 10 ³ to
Indicates a sheet resistance of 10 ⁷ Ω / □. The constituent materials of the thin film 4 including the electron emitting portion include Pd, Ru, Ag, Au,
Ti, In, Cu, Cr, Fe, Zn, Sn, Ta,
Metals such as W and Pb, PdO, SnO ₂ In ₂ O ₃ , Pb
Oxides such as O, Sb ₂ O ₃ , HfB ₂ , ZrB ₂ , La
Borides such as B ₆ , CeB ₆ , YB ₄ , GdB ₄ , Ti
Carbides such as C, ZrC, HfC, TaC, SiC, WC, etc., nitrides such as TiN, ZrN, HfN, semiconductors such as Si, Ge, carbon, AgMg, NiCu, Pb, Sn
Etc., which are composed of fine particle films.

The fine particle film described here is a film in which a plurality of fine particles are aggregated. The fine structure is not limited to a state in which the fine particles are dispersed and arranged here, but the fine particles are adjacent to each other.
Alternatively, it refers to a film in an overlapping state (including an island shape).

The electron-emitting portion 3 is made up of a large number of conductive fine particles having a particle size of several to several thousand, preferably 1 to 200, and has a film thickness of the thin film 4 including the electron-emitting portion and a method for forming a conductive condition to be described later. Is set as appropriate depending on. The constituent material of the electron-emitting portion 3 is the same as some or all of the constituent elements of the constituent material of the thin film 4.

A preferred example of the manufacturing process of the electron-emitting device of the present invention will be described with reference to FIG.

(1) After sufficiently cleaning the insulating substrate 1 with a detergent, pure water and an organic solvent, vacuum evaporation, sputtering, C
After depositing an insulator layer by a VD method or the like, a mask 8 is formed by a photolithography technique (a).

(2) Next, the conductive electrode 2 having a desired pattern is formed by doping with ion implantation, heat treatment, or the like (b).

(3) After removing the mask layer 8, an organic metal solution is applied and left to form an organic metal thin film 4. The organic metal solution is defined as Pd, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T
This is a solution of an organic compound containing a metal such as a, W, or Pb as a main element. Thereafter, the organic metal thin film 4 is heated and baked, and is patterned by lift-off, etching or the like to form the electron-emitting-portion-forming thin film 4 (c). In addition, here, the method of applying the organometallic solution has been described. However, the present invention is not limited thereto, and a vacuum evaporation method, a sputtering method, a chemical vapor deposition method,
It can be formed by a dispersion coating method, a dipping method, a spinner method, or the like.

(4) Subsequently, after forming the extraction electrode 6,
A pulsed or high-speed voltage increase is applied to the thin film 4 by a power supply (not shown), and an energization process is performed to form an electron emission portion 5 (d). FIG. 3 shows a voltage waveform of the energization process. In the figure, T ₁ and T ₂ are the pulse width and pulse interval of the voltage waveform, T ₁ is ₁ μs to 10 μs, and T ₂ is 10 μs to 10 μs.
0 ms, the peak value of the triangular wave (peak voltage at the time of forming) is about 4 V to 10 V, and the processing is performed for about several tens of seconds in a vacuum atmosphere.

In forming the above-described electron emitting portion,
Although the forming process is performed by applying a triangular wave pulse between the electrodes of the element, the waveform is not particularly limited to a triangular wave, and a desired waveform such as a rectangular wave is provided as long as the electron emitting portion is formed well. A desired value can be selected for the peak value, pulse width, pulse interval, and the like.

In the electron-emitting device of the present invention, the electrode is embedded in the substrate surface, and the step at the contact portion between the electrode and the thin film is preferably equal to or less than the thickness of the thin film, more preferably 0 ± 10 μm. Therefore, since the thin film is formed on a substantially flat surface, the contact resistance between the thin film and the electrode can be minimized, and the variation in the contact resistance between the elements can be minimized. In addition, since the thin film is formed on the electrode embedded in the substrate, the thin film does not peel off due to internal stress generated in the electrode, and exhibits good device characteristics.

As described in the prior art, the SCE is a non-linear element, and the emitted electrons are controlled to the peak value and the width of the pulse voltage applied between the opposing electrodes. Therefore, even when a large number of SCEs are arranged, an arbitrary element can be selected and the amount of electron emission can be controlled by appropriately applying the pulse voltage to each element. Hereinafter, the configuration of the electron source of the present invention configured based on this principle will be described.

FIG. 4 is a diagram showing a basic configuration of the electron source of the present invention. In the figure, 42 is an X-direction wiring, 43 is a Y-direction wiring,
44 is an SCE of the present invention, and 45 is a connection.

In the figure, the substrate 1 is the above-mentioned insulating substrate 1 of SCE, and its size and thickness
The number of CEs, the design shape of each element, and the configuration of a container are appropriately selected depending on conditions for maintaining the container in a vacuum. The m X-directional wirings 42 composed of D _X1 , D _X2 ... D _Xm and the Y-directional wiring 43 composed of n wirings D _Y1 , D _Y2 ... D _Yn are vacuum-deposited on the insulating substrate 1. A material, a film thickness, and a wiring width are set so that a substantially uniform voltage is supplied to a large number of SCEs 74 by using a conductive metal or the like formed in a desired pattern by a method, a printing method, a sputtering method, or the like. . An interlayer insulating layer (not shown) is provided between the m X-directional wirings 42 and the n Y-directional wirings 43, and electrically separated to form a matrix wiring (m and n are both positive. integer). The interlayer insulating layer (not shown) is formed by vacuum evaporation, printing, sputtering, or the like.
iO ₂ or the like, which is formed in a desired shape on the entire surface or a part of the insulating substrate 1 on which the X-direction wirings 42 are formed.
The film thickness, material, and manufacturing method are appropriately selected so as to withstand the potential difference between the intersections of the directional wirings 42 and the Y-directional wirings 43, and may be provided only at the intersections of the X-directional wirings 42 and the Y-directional wirings 43. At this time, the connection 45 and the X-direction wiring 42 or Y
The electrical connection of the directional wiring 43 can be made without using a contact hole.

Further, the electrode (not shown) of the SCE 44
The wiring 45 is electrically connected to the directional wiring 42 and the Y-directional wiring 43 by a connection 45. Connection 45 is a vacuum deposition method, a printing method,
It is made of a conductive metal or the like formed by a sputtering method or the like.

In the present invention, the X-direction wiring 42, the Y-direction wiring 43, and the connection 45 constituting the electron source are different even if they are made of the same or partially the same material as the electrodes of the element of the present invention described in the first embodiment. The material that can be used is the same as the electrode.

The X-direction wiring 42 is electrically connected to a scanning signal generating means (not shown) for applying a scanning signal for arbitrarily scanning a row of the SCEs 44 arranged in the X-direction, and is connected to the Y-direction. The wiring 43 is a SCE4 arranged in the Y direction.
It is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for arbitrarily modulating the 4th row.

Further, the drive voltage applied to each element is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element.

Next, an image forming apparatus of the present invention using the above-mentioned electron source will be described with reference to FIG. FIG. 5 is a basic configuration diagram thereof. In the drawing, reference numeral 51 denotes a rear plate to which an electron source is fixed; 56, a face plate in which a fluorescent film 54 and a metal back 55 are formed on the inner surface of a glass substrate 53; 52, a support frame; and the rear plate 51 and the face plate 56 are made of frit glass. The envelope 58 is formed by sealing.

The envelope 58 is composed of the face plate 56, the support frame 52, and the rear plate 51 as described above.
Since the rear plate 51 is provided mainly for the purpose of reinforcing the strength of the substrate 1, if the substrate 1 alone has sufficient strength, the separate rear plate 51 is unnecessary, and the support frame 52 is directly mounted on the substrate 1. After sealing, the envelope 58 may be constituted by the face plate 56, the support frame 52, and the substrate 1.

FIG. 6 shows the fluorescent film 54. Fluorescent film 54
Is composed of only a phosphor in the case of monochrome, but in the case of color, it is a black conductive material 61 called a black stripe or a black matrix depending on the arrangement of the phosphor.
And a phosphor 62. The purpose of providing the black stripes and the black matrix is to make the mixed portions inconspicuous by making the painted portions between the phosphors 62 of the three primary color phosphors necessary in the case of color display less noticeable. The purpose is to suppress a decrease in contrast due to light reflection. The material of the black stripe is not limited to the commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection. In addition, as a method of applying the phosphor on the glass substrate 53, a precipitation method or a printing method is used regardless of monochrome or color.

A metal back 55 is usually provided on the inner surface side of the fluorescent film 54. The purpose of the metal back is to improve the brightness by mirror-reflecting the light emitted from the phosphor toward the inner surface side to the face plate 56 side, to act as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from damage due to collision of negative ions generated in the enclosure. The metal back 55 can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like.

The face plate 56 is further provided with a fluorescent film 5.
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 54 in order to increase the conductivity of the phosphor film 4.

When the envelope is sealed as described above, in the case of color, the phosphors of each color must correspond to the SCE, so that it is necessary to perform sufficient alignment.

The envelope 58 is sealed by evacuating the inside through an exhaust pipe (not shown), and then D _{X1 to} D _Xm and D _{Y1 to} D _Yn.
A voltage is applied to the electrode of the SCE 44 through the external terminal of the SCE 44 to perform forming, thereby forming an electron emission portion. Further, a getter process may be performed to maintain the degree of vacuum after sealing the envelope 58. This is because the getter disposed at a predetermined position (not shown) in the envelope 58 is heated by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 58 is sealed. This is a process for forming a deposited film. The getter is usually composed mainly of Ba or the like, and the degree of vacuum is maintained by the adsorption action of the deposited film.

In the image forming apparatus of the present invention configured as described above, a voltage is applied to each SCE through a terminal outside the container to emit electrons, and the high voltage terminal H
Through _V , metal back 55 or transparent electrode (not shown)
The image is displayed by applying a high voltage of several kV or more, accelerating the electron beam to collide with the fluorescent film 54, exciting and emitting light.

The configuration described above is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display and the like. For example, detailed portions such as materials of each member are not limited to those described above. Instead, it is appropriately selected so as to be suitable for the use of the apparatus. In addition, the above-mentioned electron source is SCE in a matrix form.
, But is not limited to this.

Further, the image forming apparatus of the present invention can be used as an alternative light source for a light emitting diode of an optical printer comprising, for example, a photosensitive drum and a light emitting diode. In this case, by appropriately selecting the above-mentioned m row-directional wirings and n column-directional wirings, the present invention can be applied not only to a linear light emitting source but also to a two-dimensional light emitting source.

[0040]

【Example】

(Example 1) A manufacturing process of an electron-emitting device according to a first example of the present invention will be specifically described with reference to FIGS.

Step-a On a cleaned blue sheet glass (insulating substrate 1), a thickness of 0.5
A μm zinc oxide thin film (insulating layer 3) was formed by sputtering. The zinc oxide thin film is usually an insulating layer, but has a property of easily changing to a conductor by doping. The low efficiency of the zinc oxide thin film obtained above was 8 × 10 ⁸ Ωcm. On this zinc oxide thin film, a photoresist (AZ13
70; manufactured by Hoechst Co.) was spin-coated with a spinner and baked, and then a photomask image was exposed and developed to form a resist pattern, and the resist was used as a mask layer 8 (FIG. 2A).

Step-b The exposed portion of the zinc oxide thin film was doped with Al by ion implantation, and the electrode 2 was formed by modifying the conductor layer to have a low efficiency of 1 × 10 ³ Ωcm. Electrode interval L ₁ is 3μ
m, electrode width W ₁ is set to 300 [mu] m [FIG 2 (b)].

Step-c Next, organic Pd (ccp4230; manufactured by Okuno Pharmaceutical Co., Ltd.)
Was spin-coated with a spinner and heated and baked at 350 ° C. for 12 minutes. The thus formed thin film 4 for forming an electron emission portion is made of fine particles containing Pd as a main element.
Its film thickness is 100 ° and its sheet resistance is 5 × 10 ⁴ Ω / □.
Met. Thereafter, after forming the resist pattern used in step-a, a desired region of the fine particle thin film was removed by ion milling, and the resist pattern was removed [FIG.
(C)].

Step-d After forming a photoresist pattern of the extraction electrode 6 on the electrode 2, a Ti film having a thickness of 50 ° and an A film having a thickness of 5000 ° are formed.
u was sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form a lead electrode 6 having a desired shape [FIG. 2 (d)].

Next, forming processing of the thin film 4 was performed. Applied voltage waveform using a waveform shown in FIG. 3, T ₁
And T ₂ are the pulse width and pulse interval of the voltage waveform,
₁ was set to ₁ μs to 10 ms, T ₂ was set to 10 μs to 100 ms, the peak value of the triangular wave (peak voltage at the time of forming) was set to about 4 to 10 V, and the forming processing was appropriately set in a vacuum atmosphere for about several tens of seconds.

The electron emitting portion 5 was formed by this forming. At this time, the peeling of the electrode 2 and the thin film 4 was inspected by microscopic observation. When 100 pieces were measured, no peeling causing a failure was observed.

Further, in order to grasp the characteristics of the SCE manufactured in the above-described steps, the electron emission characteristics were measured using the measurement and evaluation apparatus shown in FIG. The measurement conditions were as follows: the distance H between the anode electrode 74 and the element was 4 mm, the potential of the anode electrode 74 was 1 kV, and the degree of vacuum in the vacuum apparatus at the time of measurement was 1 × 10 ^−6.
torr. At this time, the applied voltage was fixed at 14 V, but the change rate of _Ie was 3 after 2000 hours.
%.

Next, in the same manner as in the above steps, a plurality of electron-emitting devices are formed on the substrate 1 to form the electron source shown in FIG. 4, and the image forming apparatus shown in FIG. Was configured. However, the forming process was performed after the envelope 58 was sealed.

In the present image forming apparatus, luminance unevenness due to voltage drop caused by resistance change due to film thickness unevenness peculiar to a thin film and luminance unevenness considered to be caused by peeling are not observed, and a good image is confirmed. Was.

FIG. 8 shows an example of a display device configured so that image information provided from various image information sources such as television broadcasting can be displayed on a display panel using the SCE as an electron source. It is a figure for showing. In the figure, 100 is a display panel, 101 is a display panel driving circuit, 102 is a display controller, 103 is a multiplexer, 104 is a decoder, 105 is an input / output interface circuit, and 106 is C
PU, 107 is an image generation circuit, 108, 109 and 11
0 is an image memory interface circuit, 111 is an image input interface circuit, 112 and 113 are TV signal receiving circuits, and 114 is an input unit. (Note that when the present display device receives a signal containing both video information and audio information, such as a television signal, it naturally reproduces the audio simultaneously with the display of the video. Receiving, separating, playing, processing,
A description of a circuit related to storage, a speaker, and the like is omitted. )

Hereinafter, each part will be described along the flow of the image signal.

First, the TV signal receiving circuit 113 is a circuit for receiving a TV image signal transmitted using a wireless transmission system such as radio waves or spatial optical communication. The format of the received TV signal is not particularly limited, and may be, for example, various systems such as the NTSC system, the PAL system, and the SECAM system. Further, a TV signal (for example, a so-called high-definition TV including the MUSE system) composed of a larger number of scanning lines than the above is suitable for taking advantage of the display panel suitable for a large area and a large number of pixels. Signal source. TV received by the TV signal receiving circuit 113
The signal is output to the decoder 104.

The image TV signal receiving circuit 112 is a circuit for receiving a TV image signal transmitted using a wired transmission system such as a coaxial cable or an optical fiber. As with the TV signal receiving circuit 113, the type 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 104.

The image input interface circuit 11
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 104.

The image memory interface circuit 1
10 is a video tape recorder (hereinafter abbreviated as VTR)
Is a circuit for taking in the image signal stored in the decoder 104. The taken image signal is output to the decoder 104.

The image memory interface circuit 1
Reference numeral 09 denotes a circuit for capturing an image signal stored in the video disk, and the captured image signal is output to the decoder 104.

An image memory-interface circuit 108 is a circuit for taking in an image signal from a device storing still image data, such as a so-called still image disk.
4 is output.

The input / output interface circuit 105
Is a circuit for connecting the present display device to an output device such as an external computer, a computer network, or a printer. In addition to inputting and outputting image data and character / graphic information, control signals and numerical data can be input and output between the CPU 106 provided in the display device and the outside in some cases.

The image generating circuit 107 is provided with image data and character / graphic information input from the outside via the input / output interface circuit 105 or the CPU 106.
This is a circuit for generating display image data based on the image data and character / graphic information output from the display unit. Inside this circuit, for example, a rewritable memory for storing image data and character / graphic information, a read-only memory storing an image pattern corresponding to a character code,
A circuit necessary for generating an image such as a processor for performing image processing is incorporated therein.

The display image data generated by the present circuit is output to the decoder 104, but may be output to an external computer network or printer via the input / output interface circuit 105 in some cases.

The CPU 106 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 103, and an image signal to be displayed on the display panel is appropriately selected or combined. At that time, a control signal is generated for the display panel controller 102 in accordance with the image signal to be displayed, and a display frequency, a scanning method (for example, interlaced or non-interlaced), the number of scanning lines per screen, and the like are displayed. The operation of the device is appropriately controlled.

Further, image data and character / graphic information are directly output to the image generation circuit 107, or an external computer or memory is accessed through the input / output interface circuit 105 to access the image data or character / graphic information.
Enter graphic information.

The CPU 106 may, of course, be involved in work for other purposes. For example, like a personal computer or word processor,
It may be directly related to the function of generating and processing information.

Alternatively, by connecting to an external computer network via the input / output interface circuit 105 as described above, operations such as numerical calculations may be performed in cooperation with external devices.

The input unit 114 is connected to the CPU 106.
The user inputs commands, programs, data, or the like, and various input devices such as a joystick, a barcode reader, and a voice recognition device can be used, for example, in addition to a keyboard and a mouse.

The decoder 104 converts various image signals input from the above 107 to 113 into three primary color signals,
Alternatively, it is a circuit for inversely converting a luminance signal into an I signal and a Q signal. As shown by the dotted line in FIG.
It is desirable that the image processor 04 has an image memory therein. This is for handling television signals that require an image memory when performing inverse conversion, such as the MUSE method. In addition, the provision of the image memory facilitates the display of a still image, or the image generation circuit 10
7 and the CPU 106 in cooperation with the image processing, such as thinning, interpolating, enlarging, reducing, and combining images.

The multiplexer 103 is connected to the CPU
A display image is appropriately selected based on a control signal input from the control unit 106. That is, the multiplexer 103 selects a desired image signal from the inversely converted image signals input from the decoder 104 and outputs the selected image signal to the drive circuit 101. In that case, by switching and selecting an image signal within one screen display time, it is also 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 TV. .

The display panel controller 1
A circuit 02 controls the operation of the drive circuit 101 based on a control signal input from the CPU 106.

First, as a signal related to the basic operation of the display panel, for example, a signal for controlling an operation sequence of a drive power supply (not shown) for the display panel is output to the drive circuit 101.

As a signal related to the display panel driving method, a signal for controlling, for example, a screen display frequency and a scanning method (for example, interlace or non-interlace) is output to the drive circuit 101.

In some cases, a control signal relating to image quality adjustment such as brightness, contrast, color tone, and sharpness of a display image may be output to the drive circuit 101.

The drive circuit 101 is a circuit for generating a drive signal to be applied to the display panel 100. The drive circuit 101 converts the image signal input from the multiplexer 103 and the control signal input from the display panel controller 102. It operates on the basis of:

The function of each part has been described above. With the configuration illustrated in FIG. 8, in the present display device, image information input from various image information sources is displayed on the display panel 10.
0 can be displayed. That is, various image signals including television broadcasts are inversely converted by the decoder 104, are appropriately selected by the multiplexer 103, and are input to the drive circuit 101. On the other hand, the display controller 102 generates a control signal for controlling the operation of the drive circuit 101 according to an image signal to be displayed. The drive circuit 101 applies a drive signal to the display panel 100 based on the image signal and the control signal. Thus, an image is displayed on the display panel 100. These series of operations are performed by the CPU 10
6 is totally controlled.

In the present display device, an image memory built in the decoder 104, an image generation circuit 107
And the involvement of the CPU 106, not only displays the image information selected from the plurality of image information, but also displays, for example, enlargement, reduction, rotation, movement, edge emphasis, thinning, interpolation, It is also possible to perform image processing such as color conversion and image aspect ratio conversion, and image editing such as combining, erasing, connecting, exchanging, and fitting. In the description of the present embodiment,
Although not particularly mentioned, a dedicated circuit for processing and editing audio information may be provided as in the above-described image processing and image editing.

Accordingly, the present display device is a television broadcast display device, a video conference terminal device, an image editing device that handles still images and moving images, a computer terminal device, an office terminal device such as a word processor, a game device, and the like. It is possible to combine the functions of a single machine, etc., and has a very wide range of applications for industrial or consumer use.

FIG. 8 shows only an example of the configuration of a display device using a display panel using an SCE as an electron source, and it goes without saying that the present invention is not limited to this. For example, among the components shown in FIG. 8, circuits relating to functions that are not necessary for the purpose of use may be omitted.
Conversely, additional components may be added depending on the purpose of use. For example, when this display device is applied as a video phone, a TV camera, a voice microphone,
It is preferable to add an illuminator, a transmitting / receiving circuit including a modem, and the like to the components.

In the present display device, in particular, it is easy to reduce the thickness of the display panel using SCE as an electron source, so that the depth of the display device can be reduced. In addition, since the display panel using the SCE as the electron source is easy to enlarge the screen, has high brightness and excellent viewing angle characteristics, this display device can display images full of presence and full of power with good visibility. It is possible.

Embodiment 2 A manufacturing process of an electron-emitting device according to a second embodiment of the present invention will be described with reference to FIG. This example is the same as Example 1 except for the step of making the zinc oxide thin film conductive.

Steps -a, c, d: Same as in Example 1.

Step-b After depositing an Al thin film (30 °) by vacuum evaporation,
The resist was removed, and heat diffusion was performed by heating at 400 ° C. for 1 hour in vacuum. As a result, the portion of the zinc oxide thin film in which Al is diffused is made conductive, and the electrode 2 is formed. By this heat diffusion, low efficiency is 3 × 10 ¹ Ωc
m, and it was confirmed that the efficiency was lower by 7 orders of magnitude than before the conductivity. In this case the electrode spacing L ₁ is 3 [mu] m, electrode width W ₁ is set to 300 [mu] m.

The characteristics of the SCE manufactured in this manner are almost the same as those of the first embodiment, and an electron source and an image forming apparatus having the same characteristics can be constructed.

(Embodiment 3) As a third embodiment of the present invention,
The SCE was manufactured using a semiconductor process.

Step-a On a cleaned P-type Si substrate (insulating substrate 1), a thickness of 0.
A 5 μm Si epitaxial film was formed by a CVD method. The conductivity of this epi film can be easily changed by doping. These techniques are usually used in the process of manufacturing a MOS transistor. A photoresist (AZ1370; manufactured by Hoechst) is spin-coated on the Si epi film with a spinner, baked, and then a photomask image is exposed and developed to form a resist pattern, and the resist is used as a mask layer 8 [FIG. 2 (a)].

Step-b Next, doping of the epi film was performed by ion implantation, the exposed portion was modified into an n ⁺ layer, and the electrode 2 was formed. At this time, the electrode interval L ₁ is 2 μm and the electrode width W ₁ is 15
The thickness was set to 0 μm (FIG. 2B).

Step-c: A Cr film having a thickness of 1000 ° in the form of a thin film for forming an electron-emitting portion having an opening in the vicinity of the electrode 2 is deposited and patterned by vacuum evaporation, and an organic Pd (cc)
p4230; manufactured by Okuno Pharmaceutical Co., Ltd.) was spin-coated with a spinner and baked at 300 ° C. for 10 minutes. The thin film 4 composed of fine particles of Pd as the main element thus formed had a thickness of 75 ° and a sheet resistance of 1 × 10 ⁵ Ω / □. Thereafter, the Cr film and the fired thin film 4 were wet-etched with an acid etchant to form a desired pattern [FIG. 2 (c)].

Step-d After forming a photoresist pattern of a lead electrode on the electrode 2, a Ti film having a thickness of 50 ° and an Au film having a thickness of 5000 ° are formed.
Were sequentially deposited by vacuum evaporation, and unnecessary portions were removed by lift-off to form a lead electrode 6 having a desired shape [FIG. 2 (d)].

In the SCE manufactured in this manner, the same characteristics as those in Examples 1 and 2 were confirmed, and an excellent configuration of the electron source and the image forming apparatus was possible.

[0089]

According to the present invention, the adhesion between the thin film including the electron-emitting portion and the electrode is high, and the influence of peeling which causes a failure is prevented. As a result, it is possible to provide an image forming apparatus having stable electron emission characteristics over a long period of time, high durability, and less luminance unevenness.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of an SCE of the present invention.

FIG. 2 is a manufacturing process diagram of the SCE of the present invention.

FIG. 3 is a diagram showing an example of a voltage waveform in an energization process of an SCE of the present invention.

FIG. 4 is a diagram showing a configuration of an electron source of the present invention.

FIG. 5 is a diagram illustrating an image forming apparatus of the present invention.

FIG. 6 is a diagram illustrating a fluorescent film according to the image forming apparatus of the present invention.

FIG. 7 is a diagram showing a configuration of an apparatus for measuring and evaluating electron emission characteristics of SCE of the present invention.

FIG. 8 is a block diagram of a display device using the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Electrode 3 Insulating layer 4 Thin film 5 Electron emission part 6 Extraction electrode 8 Mask 42 X direction wiring 43 Y direction wiring 44 SCE 45 Connection 51 Rear plate 52 Supporting material 53 Glass substrate 54 Fluorescent film 55 Metal back 56 Face plate 58 envelope 61 black conductor 62 phosphor 70 ammeter 71 power supply 72 ammeter 73 high voltage power supply 74 anode electrode 100 display panel 101 drive circuit 102 display panel controller 103 multiplexer 104 decoder 105 input / output interface circuit 106 CPU 107 image generation circuit 108 Image memory interface 109 Image memory interface 110 Image memory interface 111 Image input interface 112 TV signal receiving circuit 113 T Signal receiving circuit 114 input unit

Claims (3)

(57) [Claims] 1. An electron-emitting device comprising: a thin film having an electron-emitting portion formed on a substrate having a pair of electrodes embedded in a surface so that both ends are electrically connected to the electrodes. . 2. An electron source comprising a plurality of the electron-emitting devices according to claim 1 . 3. An image forming apparatus comprising: the electron source according to claim 2 ; and an image forming member.